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Articles containing the keyword 'gene'

Category : Article

article id 5605, category Article
Matti Haapanen, Marja-Leena Annala, Pirkko Velling. (1997). Progeny trial estimates of genetic parameters for growth and quality traits in Scots pine. Silva Fennica vol. 31 no. 1 article id 5605. https://doi.org/10.14214/sf.a8506
Keywords: Pinus sylvestris; Scots pine; wood quality; genetic correlation; heritability; progeny testing
Abstract | View details | Full text in PDF | Author Info

Estimates of individual heritability and genetic correlation are presented for a set of 10 growth and quality traits based on data from 16 Scots pine (Pinus sylvestris L.) progeny trials in Finland. Seven of the traits (tree height, stem diameter, crown width, Pilodyn value, branch diameter, branch angle and branch number) were objectively measured, whereas three traits (stem straightness, branching score and overall score) were assessed visually. The genetic correlations were mostly moderate or low, and favourable from the tree breeder's point of view. All variables related to tree size correlated relatively strongly and positively. Tree height exhibited a more favourable genetic relationship with the crown form traits than diameter, the latter showing positive correlation with branch diameter. Except for the slight negative correlation between branch angle and branch diameter, the branching traits were not notably correlated. The pilodyn value was positively correlated with stem diameter, reflecting negative correlation between diameter growth and wood density. The highest genetic correlations occurred among the two visually evaluated quality scores and branch diameter. All of the heritabilities were less than 0.4. Overall score, Pilodyn, branch angle, branching score and tree height showed the highest heritability.

  • Haapanen, E-mail: mh@mm.unknown (email)
  • Annala, E-mail: ma@mm.unknown
  • Velling, E-mail: pv@mm.unknown
article id 5573, category Article
Ilkka Vanha-Majamaa, Raili Suominen, Tiina Tonteri, Eeva-Stiina Tuittila. (1996). Seedling establishment after prescribed burning of a clear-cut and a partially cut mesic boreal forest in southern Finland. Silva Fennica vol. 30 no. 1 article id 5573. https://doi.org/10.14214/sf.a9218
Keywords: Pinus sylvestris; Betula pendula; Picea abies; Betula pubescens; natural regeneration; seedling establishment; prescribed burning; controlled burning; Sorbus aucuparia; seed dispersal; mesic forest; seed rain; autoregression model; GLM
Abstract | View details | Full text in PDF | Author Info

The prescribed burning of a 7.3 ha clear-cut and a 1.7 ha partially cut forest (volume 150 m3/ha) was carried out in Evo (61 °12'N, 25°07'E) on 1 June 1992. The forest was a mesic Myrtillus site type forest dominated by Norway spruce (Picea abies (L.) H. Karst.). Practically all the trees and the above-ground parts of the understorey vegetation died in the fire, while the mor layer was thinned by an average of 1.5 cm.

A study was made on the change of germinated seedling population in time and their dependence on environmental factors. Seedlings of Norway spruce, Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth), pubescent birch (B. pubescens Ehrh.) and rowan (Sorbus aucuparia L.) were inventoried in 1993 and in 1994 on permanent plots, four times per growing season. Autoregression models were used to compare regeneration of tree species in the burned forest with regeneration in the burnt clear-cut area, and to study the effect of distance from nearest seed source to regeneration.

The average number of seedlings germinating in 1993 was higher than in 1994, probably because of differences between these consecutive years in regard to the amount of seed rain and weather conditions. The number of Norway spruce and rowan seedling was higher inside the forest area than in the clear-cut area. The distance to the bordering forest and to the closest seed tree did not explain the result. It is suggested that the more stable microclimatic conditions under the shade of dead tree promote germination and seedling establishment in the forest area. As rowan is a bird-dispersed species, it is likely that dead trees help the dispersal of rowan seed by providing birds place to sit and defecate. The shade provided by dead trees may influence the further succession of the tree stand and vegetation composition and diversity.

  • Vanha-Majamaa, E-mail: iv@mm.unknown (email)
  • Suominen, E-mail: rs@mm.unknown
  • Tonteri, E-mail: tt@mm.unknown
  • Tuittila, E-mail: et@mm.unknown
article id 5571, category Article
Katarina Lindgren, Dag Lindgren. (1996). Germinability of Norway spruce and Scots pine pollen exposed to open air. Silva Fennica vol. 30 no. 1 article id 5571. https://doi.org/10.14214/sf.a9216
Keywords: Pinus sylvestris; Picea abies; gene flow; pollen; pollen viability; conifer pollen
Abstract | View details | Full text in PDF | Author Info

Germination of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) pollen decreased during exposure to open air conditions. Usually more than half of the pollen remained germinative after a few days outdoors, but following more than four days outdoors the germination became very low. This study supports the opinion that pollen in the atmosphere remains viable long enough to allow for long-distance gene flow by pollen migration, as an important factor in genetic management of conifers and in evolution, maintaining diversity and potential for adaptation.

  • Lindgren, E-mail: kl@mm.unknown (email)
  • Lindgren, E-mail: dl@mm.unknown
article id 5562, category Article
Janne Uuttera, Matti Maltamo. (1995). Impact of regeneration method on stand structure prior to first thinning. Comparative study North Karelia, Finland vs. Republic of Karelia, Russian Federation. Silva Fennica vol. 29 no. 4 article id 5562. https://doi.org/10.14214/sf.a9213
Keywords: natural regeneration; stand structure; artificial regeneration; potential biodiversity; regeneration strategy
Abstract | View details | Full text in PDF | Author Info

Comparisons were made between artificially and naturally regenerated stands in the south-eastern part of North Karelia, Finland, and naturally regenerated stands in the western parts of the Republic of Karelia, Russian Federation. The effect of soil fertility and silvicultural operations on the stand structure was also investigated.

The results of the study show clearly that when forests are artificially regenerated the stand structure includes less variation when compared with the stands naturally regenerated. Differences between the regeneration methods are clearer the more fertile the forest site is. Within the regeneration method there is also a clear trend in stand structure, with the variation decreasing the poorer the site. The effect of silvicultural operations, i.e. the cleaning of the sapling stand, has disappeared by the time of first thinning, although it appears to have a permanent effect on the dynamics of the tree species within a stand.

The variation of the stand structure can be regarded as an essential factor for the potential biodiversity of the stand also at its young vegetation succession stage. This capacity for maintaining the forest biodiversity, developed at the young vegetation succession stage, becomes increasingly important in subsequent vegetation succession stages. Natural regeneration provides improved possibilities for the operations preserving forest biodiversity, as it generates more dense stands with a wider variation in stand structure, compared to artificial regeneration.

  • Uuttera, E-mail: ju@mm.unknown (email)
  • Maltamo, E-mail: mm@mm.unknown
article id 5557, category Article
Klaus Silfverberg. (1995). Forest regeneration on nutrient-poor peatlands: Effects of fertilization, mounding and sowing. Silva Fennica vol. 29 no. 3 article id 5557. https://doi.org/10.14214/sf.a9208
Keywords: Pinus sylvestris; Betula; soil preparation; natural regeneration; drained peatlands; mounding; ground vegetation; sowing; seedling number
Abstract | View details | Full text in PDF | Author Info

The effects of wood ash and PK fertilization on natural regeneration and sowing of Scots pine (Pinus sylvestris L.) were studied in field experiments on nitrogen-poor (Ntot 0.87–1.26%) peat substrates. The study material was derived from three drained, nutrient-poor pine mires (64°52’ N, 25°08’ E) at Muhos, near Oulu, Finland. The experimental fields were laid out in 1985 as a split-split-plot design including the following treatments; mounding, natural regeneration and sowing and fertilization; PK (400 kg ha-1) and wood ash (5,000 kg ha-1). The seedlings were inventoried in circles in July–August 1991.

Changes in the vegetation were small and there were no statistical differences due to the fertilization treatments in the ground vegetation. PK or ash fertilization did not cause vegetation changes harmful to Scots pine regeneration on nitrogen-poor peatlands. Both sowing and fertilization significantly increased the number of pine seedlings, but not their height. Wood ash increased seedling number more than PK fertilizer. The number of seedlings varied from 7,963 (control) to 42,781 ha-1 (mounding + sowing + ash). The seedling number was adequate for successful regeneration even on non-mounded, non-fertilized naturally regenerated plots.

The number of birch seedlings varied more than that of pine (370–25,927 ha-1). Mounding especially increased the number of birches. The difference between PK fertiliser and ash was less pronounced than that for pine. In addition, to the field studies the effects of ash and PK fertilizer on the germination of Scots pine seeds was studied in a greenhouse experiment. Soaking in ash solutions strongly reduced seed germination, while the PK solution was less harmful.

  • Silfverberg, E-mail: ks@mm.unknown (email)
article id 5552, category Article
Liisa Saarenmaa, Timo Leppälä. (1995). Fill-in seedlings in constituting the stocking of Scots pine stands in northern Finland. Silva Fennica vol. 29 no. 2 article id 5552. https://doi.org/10.14214/sf.a9203
Keywords: Pinus sylvestris; planting; spatial pattern; artificial regeneration; fill planting; survival of seedlings
Abstract | View details | Full text in PDF | Author Info

Fill planting is a common procedure following reforestation in Finland. In 1990, 13% of the total of seedlings planted was used for fill planting. The objective of this study is (i) to survey the survival of fill-in seedlings and (ii) to estimate the spatial pattern of stands to evaluate the importance of fill-in seedlings in constituting the stocking of Scots pine (Pinus sylvestris L.) stands in Central and Northern Finland.

A survey of 63 artificially regenerated Scots pine stands was conducted in 1990. Stand densities varied from 950 to 3,925 seedlings/ha. The mean densities of originally planted, fill planted and naturally regenerated seedlings were 863, 639 and 791/ha, respectively. The survival of originally planted seedlings was 36% and that of fill-in seedlings 48%. Death rate of fill-in seedlings of Scots pine increased with longer times between original and fill planting. The survival rate of Norway spruce (Picea abies) seedlings was correlated with temperature sum. Height of the fill-in seedlings was less than that of the originally planted ones. Most stands had an even spatial distribution with the exception of sparsely populated stands, which were somewhat clustered. This indicates that dying of seedlings is not randomly spread. Because of poor survival, fill planting seems to be a risky business in most cases.

  • Saarenmaa, E-mail: ls@mm.unknown (email)
  • Leppälä, E-mail: tl@mm.unknown
article id 5546, category Article
Oliver Schabenberger, Timothy G. Gregoire. (1995). A conspectus on Estimating Function theory and its applicability to recurrent modeling issues in forest biometry. Silva Fennica vol. 29 no. 1 article id 5546. https://doi.org/10.14214/sf.a9197
Keywords: modelling; mixed models; statistical methods; longitudinal data; generalized linear models; optimality
Abstract | View details | Full text in PDF | Author Info

Much of forestry data is characterized by a longitudinal or repeated measures structure where multiple observations taken on some units of interest are correlated. Such dependencies are often ignored in favour of an apparently simpler analysis at the cost of invalid inferences. The last decade has brought to light many new statistical techniques that enable one to successfully deal with dependent observations. Although apparently distinct at first, the theory of Estimating Functions provides a natural extension of classical estimation that encompasses many of these new approaches. This contribution introduces Estimating Function Theory as a principle with potential for unification and presents examples covering a variety of modelling issues to demonstrate its applicability.

  • Schabenberger, E-mail: os@mm.unknown (email)
  • Gregoire, E-mail: tg@mm.unknown
article id 5539, category Article
Tore Skrøppa. (1994). Impacts of tree improvement on genetic structure and diversity of planted forests. Silva Fennica vol. 28 no. 4 article id 5539. https://doi.org/10.14214/sf.a9179
Keywords: diversity; tree breeding; seed orchards; production; adaptability; genetic factors; trees
Abstract | View details | Full text in PDF | Author Info

After a presentation of basic biodiversity concepts, reviews are made of studies reporting genetic implications of tree improvement activities: seed treatments, seedling production, provenance transfers, plus tree selection, seed production in seed orchards and progeny testing.

Several of the activities may influence the genetic structure and diversity of the planted forests. The general conclusion is, however, that planted forests are at least as genetically diverse as the natural stands that they replace. The diversity in forest management and use is best assurance for the future adaptability of the forests.

  • Skrøppa, E-mail: ts@mm.unknown (email)
article id 5537, category Article
Anu Mattila, Anne Pakkanen, Juha Raisio, Pekka Vakkari. (1994). Genetic variation in English oak (Quercus robur) in Finland. Silva Fennica vol. 28 no. 4 article id 5537. https://doi.org/10.14214/sf.a9177
Keywords: Quercus robur; allozymes; populations; genetic differences; heterozygosity
Abstract | View details | Full text in PDF | Author Info

Genetic variation in 5 natural stands of Quercus robur L. in Finland was analysed electrophoretically for 13 isozyme loci. Stands were on average polymorphic at 49.2% of the loci, with 2.1 alleles per locus. Observed heterozygosities, ranging from 13.6% to 16.9%, were slightly lower than estimates reported for German stands. The majority of the species’ genetic variation was found within each studied stand, and only 5.5% was between stands. Mean genetic differentiation (∂) was the same as that found in the primary range of the species, but the differentiation estimates (D) for single Finnish population were more variable.

  • Mattila, E-mail: am@mm.unknown (email)
  • Pakkanen, E-mail: ap@mm.unknown
  • Raisio, E-mail: jr@mm.unknown
  • Vakkari, E-mail: pv@mm.unknown
article id 5534, category Article
Hyun Kang, Inger Ekberg, Gösta Eriksson, Johan Ununger. (1994). Second and third growth period responses of Picea abies families to first growth period photoperiodic, light intensity and temperature treatments. Silva Fennica vol. 28 no. 4 article id 5534. https://doi.org/10.14214/sf.a9174
Keywords: Picea abies; growth; maturation; temperature; seedlings; photoperiod; environmental effects; genetic effects; juvenility
Abstract | View details | Full text in PDF | Author Info

Seedlings of Picea abies (L.) H. Karst. full-sib families of contrasting origins were cultivated in a phytotron under different photoperiodic, light-intensity and temperature treatments during their first growth period. The effects of the treatments on juvenile growth traits – whether enhanced or delayed maturation was induces – were observed during the two subsequent growth periods. The following hypotheses were tested: (A) Enhanced maturation can be induced in the first growth period from sowing with (i) a long period of continuous light during active growth (24 weeks vs. 8 weeks); (ii) a shorter night during bud maturation (12 h vs. 16 h); high temperature (25°C vs. 20°C) during (iii) active growth, growth cessation and bud maturation; and during (iv) the latter part of growth cessation and bud maturation only. (B) Delayed maturation can be induced after (i) low light intensity during growth cessation and bud maturation (114 μmol m-2 s-1 vs. 340 μmol m-2 s-1); low temperature (15°C vs. 20°C) during (ii) active growth, growth cessation and bud maturation; and during (iii) the latter part of growth cessation and bud maturation only.

The most dramatic effect was observed after 24 weeks of continuous light during active growth. All traits showed a significantly more mature performance in the second growth period compared with the control. The effect for all but one trait was carried over to the third growth period. This is in accordance with the hypothesis that the activity of apical shoot meristems controls the maturation process. For the other treatments there was only weak or no support for the hypothesis of induction of enhanced or delayed maturation. Strong family effects were observed for all traits. Differential responses of the various latitudinal families were observed, suggesting that family effects must be considered to predict and interpret correctly how plants will respond to environmental effects.

  • Kang, E-mail: hk@mm.unknown (email)
  • Ekberg, E-mail: ie@mm.unknown
  • Eriksson, E-mail: ge@mm.unknown
  • Ununger, E-mail: ju@mm.unknown
article id 5400, category Article
Kari J. Jokinen, Don J. Durzan. (1994). Properties of rescued embryonal suspensor masses of Norway spruce determined by the genotype and the environment in vitro. Silva Fennica vol. 28 no. 2 article id 5400. https://doi.org/10.14214/sf.a9165
Keywords: Norway spruce; Picea abies; growth; somatic embryogenesis; callus
Abstract | View details | Full text in PDF | Author Info

53 genotypes of embryonal suspensor masses (ESMs) rescued from mature seeds of Norway spruce (Picea abies (L.) H. Karst.) were examined for their pattern of growth and development under standardized culture conditions in vitro. Patterns were classified according to the colour of the colonies grown in darkness, clarity of cell masses and proembryos in the mucilaginous ESM, surface boundary topology of colonies, structure of suspensors, growth rate of the ESM, and recovery of mature embryos.

Five distinctive major growth patterns were observed among ESM colonies under standardized culture conditions. The multiplication of proembryos and early embryos by cleavage and budding polyembryony was the main factor contributing to proliferation and colony growth and further determined the morphology of the colonies. Callus and teratological structures were induced from early embryos by changing the standardized culture conditions i.e. inadequate subculture, excessive dose of 2,4-D in the medium and premature exposure of the colonies to light. Results enable the selection of ESM genotypes for the predictable recovery of mature somatic embryos.

  • Jokinen, E-mail: kj@mm.unknown (email)
  • Durzan, E-mail: dd@mm.unknown
article id 5466, category Article
Hely Häggman. (1991). Application of biotechnology to forest tree breeding. Silva Fennica vol. 25 no. 4 article id 5466. https://doi.org/10.14214/sf.a15624
Keywords: tree breeding; micropropagation; vegetative propagation; somatic embryogenesis; conventional breeding; somaclonal variation; biotechnology; gene transfer
Abstract | View details | Full text in PDF | Author Info

Forest tree breeding involves manipulation of genetic composition of populations and individuals, and biotechnology focuses on selected individuals. The new techniques cannot replace the conventional breeding techniques but both need effective cooperation of each other. Thus, the distinction between conventional breeding and biotechnology is artificial. The biotechnology methods are new and fast developing and the future with field and progeny testing will show which techniques will be permanently adopted into tree breeding. For instance, the earlier hope of the use of somaclonal variation as a new source of variability and a powerful tool for the breeder seem today quite the opposite. Somaclonal variation constituting a major problem in present-day micropropagation is due to the unpredictable variation. Based on knowledge of today, especially micropropagation via somatic embryos, transgenic trees and the identification of major genes seem to be good candidates to be permanently adopted into tree breeding.

  • Häggman, E-mail: hh@mm.unknown (email)
article id 5460, category Article
R. C. Schmidtling. (1991). Effect of rootstock and scion on flowering, growth and foliar nutrients of loblolly pine (Pinus taeda) grafts. Silva Fennica vol. 25 no. 4 article id 5460. https://doi.org/10.14214/sf.a15618
Keywords: seed orchards; Pinus taeda; grafting; incompatibility; genetics
Abstract | View details | Full text in PDF | Author Info

In two separate studies, seedlings from 20 loblolly pine (Pinus taeda L.) families and Virginian pine (Pinus virginiana Mill.) were used as root stocks for grafting loblolly pine seed orchard clones. The rootstocks were open-pollinated seedlings from orchard clones chosen to represent a wide range of flowering and survival capabilities, based on their performance in a first-generation seed orchard. Scions were derived from the same 20 loblolly clones. The effects of scion clone were significant and large for nearly all measured traits. Rootstock significantly affected survival, growth, flowering and foliar nutrients of the grafted ramets. Neither survival nor growth of the crafts was related to survival of growth of the orchard clones from which their rootstocks were derived, however. Survival of incompatible clones was enhanced by grafting on genetically related rootstocks.

The PDF includes an abstract in Finnish.

  • Schmidtling, E-mail: rs@mm.unknown (email)
article id 5458, category Article
Jaroslaw Burczyk, Grzegorz Kosiński, Andrzej Lewandowski. (1991).  . Silva Fennica vol. 25 no. 4 article id 5458. https://doi.org/10.14214/sf.a15616
English title: Mating pattern and empty seed formation in relation to crown level of Larix decidua (Mill.) clones.
Keywords: seeds; crown; Larix decidua; mating systems; genetic load; grafting
Abstract | View details | Full text in PDF | Author Info

The mating system was analysed in the upper and lower crown of two groups of European larch (Larix decidua Mill.) clones divided according to the percentage of full seeds in the upper and lower crown parts. The overall multilocus estimate of outcrossing rate (t) was calculated to be 0.929. The differences of outcrossing rates between crown levels and clonal groups respectively were not statistically significant. The t estimates were greater for the upper crown level and for clones with higher percentage of full seeds in the upper crown level. However, among all observations there was no correlation between outcrossing rates and percentages of full seeds for particular crown levels and groups of clones. Observed similarity of outcrossing among grafts of the same clones may indicate genetic control of self-fertilization rate in individual European larch. 

The PDF includes an abstract in Finnish.

  • Burczyk, E-mail: jb@mm.unknown (email)
  • Kosiński, E-mail: gk@mm.unknown
  • Lewandowski, E-mail: al@mm.unknown
article id 5445, category Article
Taneli Kolström. (1991). Kuusen kylvö- ja istutuskoe viljavilla kivennäismailla Pohjois-Karjalassa. Silva Fennica vol. 25 no. 2 article id 5445. https://doi.org/10.14214/sf.a15599
English title: Results from the sowing and planting experiment of Norway spruce (Picea abies) on fertile sites in North Karelia, Finland.
Original keywords: kuusi; kylvö; istutus; metsänuudistaminen; heinäntorjunta; kuolleisuus; pituuskasvu
English keywords: Picea abies; height growth; planting; mortality; sowing; artificial regeneration; survival rate; control of ground vegetation
Abstract | View details | Full text in PDF | Author Info

Different methods of sowing and planting of Norway spruce (Picea abies (L.) H. Karst.) were compared on fertile sites in North Karelia (62°20’N, 29°35’E, 85–120 m a.s.l.). The planting material were 4-year-old bare-rooted transplants, 2-year-old bare-rooted seedlings, and 2-year-old containerized seedlings raised in plastic greenhouse. The sowing methods were band sowing and shelter sowing. Ground vegetation was controlled during the first growing season mechanically or chemically, or the control was omitted totally.

Planting of spruce gave better results than sowing. After eight growing seasons there were sowed seedlings left in 30% of the sowing pots. The average height of them was 35 cm. Seedling survival was best with large bare-rooted transplants (91%). Survival of containerized seedlings was 79% and of small bare-rooted transplants 71%. The average height of large bare-rooted transplants was 131 cm, of containerized seedlings 86 cm and small bare-rooted seedlings 68 cm.

Sowing is not an advisable method for regeneration of spruce due to the small survival rate and slow initial development when ground vegetation is controlled only once. Also 2-year-old seedlings gave a satisfactory result in regeneration. Seedlings raised in greenhouse were more sensitive to frost damage than seedlings grown on open ground.

The PDF includes an abstract in English.

  • Kolström, E-mail: tk@mm.unknown (email)
article id 5420, category Article
Toyohiro Miyazava, Jukka Laine. (1990). Effect of macroclimate on the development of Scots pine seedling stands on drained oligotrophic pine mires. Silva Fennica vol. 24 no. 2 article id 5420. https://doi.org/10.14214/sf.a15574
Keywords: Pinus sylvestris; fertilization; regeneration; drained peatlands; plantations; ditch spacing; effective temperature sum; microtopography
Abstract | View details | Full text in PDF | Author Info

The influence of different fertilization treatments and ditch spacings on the height growth of young Scots pine (Pinus sylvestris L.) seedling stands growing under various climatic regimes were determined. Comparisons were made between naturally regenerated and planted seedling stands. The effective temperature sum had a stronger effect on the height growth of planted seedlings, and in Northern Finland the planted seedlings seemed to be influenced to a greater degree by the adverse climatic conditions. The heavier the dose of fertilizer that had been applied, the greater the difference in growth caused by macroclimate. A considerably larger proportion of natural seedlings were located on hummocks compared with that of planted seedlings, irrespective of the region. On plots with wider ditch spacings, seedlings growing on hummocks were superior in height growth to those on flat surfaces.

The PDF includes an abstract in Finnish.

  • Miyazava, E-mail: tm@mm.unknown (email)
  • Laine, E-mail: jl@mm.unknown
article id 5415, category Article
Kim von Weissenberg. (1990). Host-parasite relationships in forest ecosystems: A review. Silva Fennica vol. 24 no. 1 article id 5415. https://doi.org/10.14214/sf.a15567
Keywords: Pinus; resistance; Ophiostoma; rust diseases; Cronartium; Cryphonectria; Melampsora; polygenic; oligogenic; gene-for-gene
Abstract | View details | Full text in PDF | Author Info

Based on a survey of world literature it is concluded that 1) the better -researched epidemic forest pathosystems are caused by anthropogenic factors, 2) the systems most likely have a polygenic background, and 3) resistance breeding should maintain polygenic resistance with restrictive incorporation of oligogenic resistance. Corresponding objectives are valid in breeding programs of presently balanced pathosystems, which may turn epidemic if man causes changes in the gene pool and alters critical environmental conditions.

The PDF includes an abstract in English.

  • Weissenberg, E-mail: kw@mm.unknown (email)
article id 5413, category Article
Eljas Pohtila. (1990). Metsän uudistuminen Kivalon vanhoilla kaistalehakkuualoilla. Silva Fennica vol. 24 no. 1 article id 5413. https://doi.org/10.14214/sf.a15565
English title: Forest regeneration of old strip cutting areas in Kivalo.
Original keywords: kuusi; metsänhoito; luontainen uudistaminen; Lappi; kaistalehakkuu
English keywords: Picea abies; natural regeneration; northern Finland; strip cutting; spruce stands
Abstract | View details | Full text in PDF | Author Info

The results of regenerating 54 and 36–38-year old strip cuttings were surveyed in the Kivalo Research Forest (N 66°20’, E 26°40’). 15 measurement plots were placed on each strip. The most common forest type was Hylocomnium-Myrtillus type. Regeneration of the strips proved to be slow. Most of the spruces growing on the strips probably originated from the time before the cutting. The average number of stems was 1,155 per ha, of which one third consisted of broadleaved trees. The average volume increment of stem wood after cutting had been about 1 m3/ha/yr, but it was increasing at the time of the inventory. Both the reforestation of the strips and the development of the emergent stands were dependent on elevation and site fertility. Site fertility was indicated by the abundance of Vaccinium myrtillus.

The PDF includes an abstract in English.

  • Pohtila, E-mail: ep@mm.unknown (email)
article id 5412, category Article
Jari Parviainen. (1990). Metsäpuiden paakkutaimituotannon nykynäkymät. Silva Fennica vol. 24 no. 1 article id 5412. https://doi.org/10.14214/sf.a15564
English title: Future trends for containerized tree seedling production: A literature review.
Original keywords: metsänuudistaminen; juuristo; kustannukset; paakkutaimituotanto; taimilaatu; epämuodostumat
English keywords: regeneration; containerized seedlings; costs; spacing; quality; tree nurseries; root systems; deformations
Abstract | View details | Full text in PDF | Author Info

Containerized tree seedlings will be used on an increasing scale in the future in different parts of the world. There are number of techniques for the production of small one-year-old seedlings but it has not been possible to develop a completely satisfactory methods for large containerized seedlings production. In the long-term development of pine plantations established with containerized seedlings the greatest problem has been deformation of the root system. With a new method, based on a sheet of peat and root pruning, it has been possible to produce conifer seedlings with a good root regeneration potential and favourable morphological root system development. The use of small containerized seedlings allows an increase in planting density without any marked increase in regeneration costs.

The PDF includes an abstract in English.

  • Parviainen, E-mail: jp@mm.unknown (email)
article id 5379, category Article
Timo Kuuluvainen, Timo Pukkala. (1989). Effect of Scots pine seed trees on the density of ground vegetation and tree seedlings. Silva Fennica vol. 23 no. 2 article id 5379. https://doi.org/10.14214/sf.a15536
Keywords: Pinus sylvestris; natural regeneration; spatial variation; ground vegetation; seedlings; seed trees; regeneration models; ecological fields; resource consumption; competitive interface
Abstract | View details | Full text in PDF | Author Info

The study uses the methodology of ecological field theory to model the effect of Scots pine (Pinus sylvestris L.) seed trees on the density of tree seedlings and other plants in the field layer. The seed trees had a clear effect on the expected value of the amount and distribution of the ground vegetation. The vicinity of seed trees had an adverse effect on the growth of grasses, herbs and seedlings, while mosses were most abundant near the trees. Models based on the ecological field approach were derived to describe the effect of seed trees on the ground vegetation.

The PDF includes an abstract in Finnish.

  • Kuuluvainen, E-mail: tk@mm.unknown (email)
  • Pukkala, E-mail: tp@mm.unknown
article id 5365, category Article
Pasi Puttonen. (1988). Metsänuudistamistutkimuksen arvioinnin seminaari 28.4.1988. Silva Fennica vol. 22 no. 4 article id 5365. https://doi.org/10.14214/sf.a15522
English title: Presentation report of evaluation group on forest regeneration research in Finland.
Original keywords: metsäntutkimus; metsänuudistaminen; Suomen Akatemia; arviointi
English keywords: evaluation; forest research; forest regeneration research; Academy of Finland
Abstract | View details | Full text in PDF | Author Info

The Academy of Finland commissioned a review of forest regeneration research. This paper summarises the evaluation. The report deals with the individual research projects and, in addition, the international evaluation group gives several recommendations to develop the forest regeneration research further. The recommendations concern education and training, publications, peer review, experimental design, routine work and extension service, and technology transfer. The paper also includes comments of the Finnish Forest Institute, the Finnish Society of Forest Science and a research scientist on the results of the evaluation.

The PDF includes a summary in English.

  • Puttonen, E-mail:
article id 5350, category Article
Heikki Hänninen, Paavo Pelkonen. (1988). Frost hardiness and over-wintering of forest trees. Silva Fennica vol. 22 no. 3 article id 5350. https://doi.org/10.14214/sf.a15507
Keywords: frost hardiness; breeding; frost damage; genetic variation; dormancy; annual cycle of development; nursery management
Abstract | View details | Full text in PDF | Author Info

This issue of Silva Fennica consists of eight articles, which are based on a co-nordic conference ”Frost hardiness and over-wintering in forest tree seedlings”, held in Joensuu, Finland, during December 1–3, 1986. The whole annual cycle of the trees is considered. Emphasis is given on methods for the study of frost hardiness, genetic variation in frost hardiness, nitrogen metabolism, bud dormancy release, and joint effect of natural and anthropogenic stress factors in the winter damage of forest trees. Practical implications for tree breeding and nursery management are discussed.

The PDF includes an abstract in Finnish.

  • Hänninen, E-mail:
  • Pelkonen, E-mail:
article id 5311, category Article
Timo Pukkala. (1987). Kuusen ja männyn siemensadon ennustemalli. Silva Fennica vol. 21 no. 2 article id 5311. https://doi.org/10.14214/sf.a15468
English title: Model for predicting the seed crop of Picea abies and Pinus sylvestris.
Original keywords: kuusi; mänty; luontainen uudistaminen; Lappi; siemensato; lämpötila; kukinnan aloitus; ennustemalli
English keywords: Pinus sylvestris; Norway spruce; Picea abies; natural regeneration; Scots pine; Finland; Lapland; predictive modelling; seed crop; flowering initiation; influence of temperature
Abstract | View details | Full text in PDF | Author Info

The seed crop of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) is predicted with the help of mean monthly temperatures during May–August one and two years before the flowering year. The prediction models were made separately for Lapland and for the rest of Finland. The models are based on 10-year periods of seed crop measurements and climatic data. The total number of time series was 59.

In Lapland, Norway spruce flowered abundantly and produced an abundant seed crop after warm July–August and two years after cool July–August. In other parts of Finland, warm June and July produced a good flowering year, especially if these months were cool two years before the flowering year.

In Lapland, Scots pine flowered abundantly if the whole previous growing season was warm. Elsewhere in Finland, a cool June preceded prolific flowering in the coming year if the rest of the growing season was considerably warmer than the average.

The prediction models explained 37–49 % of the variation in the size of the seed crop. The occurrence of good and poor seed years was usually predicted correctly. Using the presented models, the prediction of the seed crop is obtainable 1.5 year for Norway spruce and 2.5 year for Scots pine before the year of seed fall.

The PDF includes an abstract in English.

  • Pukkala, E-mail: tp@mm.unknown (email)
article id 5302, category Article
Seppo Kellomäki, Heikki Hänninen, Taneli Kolström, Ahti Kotisaari, Timo Pukkala. (1987). A tentative model for describing the effects of some regenerative process on the properties of natural seedling stands. Silva Fennica vol. 21 no. 1 article id 5302. https://doi.org/10.14214/sf.a15459
Keywords: Pinus sylvestris; natural regeneration; Scots pine; modelling; stand density; seed crop; seed dispersal; parent tree
Abstract | View details | Full text in PDF | Author Info

The effect of the size of seed crop, dispersal of seeds and the early development of seedlings on the density and spatial distribution of young Scots pine (Pinus sylvestris L.) stands are evaluated on the basis of theoretical models. The models include (i) number and spatial distribution of parent trees on the regeneration area, (ii) size of annual seed crop, (iii) seed dispersal from a particular parent tree, (iv) germination of the seeds (germination percentage), (v) death of ageing seedlings after the establishment process, and (vi) height growth of the seedlings.

As expected, stand density and spatial distribution varied within a large range in relation to the density of the parent trees and the distance from them. The simulations also showed that natural seedling stands can be expected to be heterogenous due to the geometry of seed dispersal, emphasizing the frequency of young and small trees. The properties of the seedling stands were, however, greatly dependent on the density of the parent trees and the length of the regeneration period.

The PDF includes an abstract in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
  • Hänninen, E-mail: hh@mm.unknown
  • Kolström, E-mail: tk@mm.unknown
  • Kotisaari, E-mail: ak@mm.unknown
  • Pukkala, E-mail: tp@mm.unknown
article id 5243, category Article
Eljas Pohtila, Tapani Pohjola. (1985). Maan kunnostus männyn viljelyssä Lapissa. Silva Fennica vol. 19 no. 3 article id 5243. https://doi.org/10.14214/sf.a15422
English title: Soil preparation in reforestation of Scots pine in Lapland.
Original keywords: mänty; istutus; kulotus; maanmuokkaus; Lappi; laikutus; lautasauraus; uudistustavat; hajakylvö
English keywords: Pinus sylvestris; soil preparation; Scots pine; planting; regeneration methods; scalping; prescribed burning; disc ploughing; broadcast sowing
Abstract | View details | Full text in PDF | Author Info

The study deals with the interaction of various soil preparation and reforestation methods. The most favourable time of the year for broadcast sowing and the effect of stabilization after soil preparation on restocking were studied as special problems.

Prescribed burning, scalping and disc ploughing made a better combination with sowing than planting, and ploughing better combination with planting than sowing. The longer the period was between sowing and germination the fewer seedlings emerged. The best stocking was clearly resulted with sowing in June. Stabilization of soil after preparation had a negative effect on reforestation results.

The PDF includes a summary in English.

  • Pohtila, E-mail: ep@mm.unknown (email)
  • Pohjola, E-mail: tp@mm.unknown
article id 5227, category Article
Harri Vasander, Tapio Lindholm. (1985). Tulen voimakkuus ja maanpinnan lämpötila kulotuksen aikana. Silva Fennica vol. 19 no. 1 article id 5227. https://doi.org/10.14214/sf.a15406
English title: Fire intensities and surface temperatures during prescribed burning.
Keywords: regeneration; slash; prescribed burning; logging waste; controlled burning; surface temperatures; fire intensity
Abstract | View details | Full text in PDF | Author Info

Surface temperature during two prescribed burnings were measured in 1983 in Evo, Southern Finland. Surface temperatures in relation to the amount of slash burned, energy released during the fires, and the fire intensities were studied. The fire intensity was also measured during a third burn. The Lake Nimetön site was burned int the end of May. Due to the uneven distribution of slash, colonization by Calamagrostis arundinacea and the spring moisture, the burning was very uneven. Surface temperatures varied between 410–809°C and the intensity of fire was low (range 0–900 kW/m).

The fire intensity on the other sites burned in May was also low (880 kW/m). During the burn in August the surface temperatures varied between 701–869°C and the intensity of fire was moderate (1,170 kW/m). Slash was burned more evenly and more thoroughly due to the dryness of the site and slash and the fact that grasses and other herbs were not abundant.

The PDF includes a summary in Finnish.

  • Vasander, E-mail: hv@mm.unknown (email)
  • Lindholm, E-mail: tl@mm.unknown
article id 5218, category Article
Jouni Suoheimo. (1984). Isokorvakärsäkkään aikuisten esiintyminen ja merkitys männyn luontaiselle uudistamiselle Pohjois-Lapissa. Silva Fennica vol. 18 no. 3 article id 5218. https://doi.org/10.14214/sf.a15397
English title: The occurrence of Otiorrhynchus nodosus and its significance for the natural regeneration of Scots pine in Lapland.
Original keywords: hyönteistuhot; mänty; luontainen uudistaminen; taimituhot; Pohjois-Lappi; isokorvakärsäkäs
English keywords: Pinus sylvestris; natural regeneration; Scots pine; insect damage; seedling damages; weevils; occurrence
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to survey the occurrence of Otiorrhynchus nodosus Müller weevils and their significance for the natural regeneration of Scots pine (Pinus sylvestris L.). The study was carried out during summer 1982 at Inari in northern Lapland.

There were two sample plots, one situated in a Scots pine seed-tree area and the other, the control sample plot, in an area with a coverage of mountain birch (Betula pubescens subsp. tortuosa, now subsp. czerepanovii). A total of 177 Otiorhynchus weevils were caught. Movement of the weevils reached its climax in July. There were 86% more individuals in the seed-tree area than in the mountain birch area. No damage to the pine germlings or seedlings was not observed, although the situation could be different during the peaks of the veewil populations.

The PDF includes a summary in English.

  • Suoheimo, E-mail: js@mm.unknown (email)
article id 5198, category Article
Leo Heikurainen, Jukka Laine, Jarmo Lepola. (1983). Lannoitus- ja sarkaleveyskokeita karujen rämeiden uudistamisessa ja taimikoiden kasvatuksessa. Silva Fennica vol. 17 no. 4 article id 5198. https://doi.org/10.14214/sf.a15181
English title: Fertilization and ditch spacing experiments concerned with regeneration and growth of young Scots pine stands on nutrient poor pine bogs.
Original keywords: mänty; luontainen uudistaminen; istutus; uudistaminen; lannoitus; ojitetut suot; taimikot; pituuskasvu; sarkaleveys
English keywords: Pinus sylvestris; fertilization; regeneration; natural regeneration; drained peatlands; Scots pine; height growth; planting; ditch spacing
Abstract | View details | Full text in PDF | Author Info

The effects of variations in the intensity of drainage and NPK fertilization on the natural regeneration and planting results and the subsequent development of seedling stands under various climatic conditions on drained nutrient poor pine bogs was investigated in a 16-year-old study.

Comparison of height development of Scots pine (Pinus sylvestris L.) stands on drained peatlands to that of pine stands growing in mineral soil sites show that in Southern Finland the most efficient forest improvement measures (10 m ditch spacing and 1,000 kg/ha NPK-fertilization) resulted in growth that corresponds a to a height index of a stand in a Vaccinium type site. Less efficient treatment (30 m ditch spacing and no fertilizer) resulted in growth corresponding the development of young stand in a Calluna type site. In Northern Finland the effect of fertilization on height growth was almost negligible. This is possibly due to a decrease in the nitrogen mobilization from south to north of Finland. Thus, it seems evident that fertilization of young Scots pine stands on nutrient poor drained peatlands can be recommended only in the southern part of the country.

The effect of ditch spacing is same in the whole country. The narrower the spacing the better the height growth. In the south planted stands thrive better than naturally regenerated stands, but the situation is reversed in the north.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@mm.unknown (email)
  • Laine, E-mail: jl@mm.unknown
  • Lepola, E-mail: jl@mm.unknown
article id 5191, category Article
Juha Lappi. (1983). Metsänuudistamisen vaatiman ajan merkitys uudistamispäätöksissä. Silva Fennica vol. 17 no. 3 article id 5191. https://doi.org/10.14214/sf.a15174
English title: Elevation of the time factor in reforestation decisions.
Original keywords: metsänuudistaminen; metsäsuunnittelu; kustannukset; uudistamisen viivästyminen; uudistumisaika; normaalimetsälaskelma; nollakorkomenetelmä; päätehakkuuikä; nykyarvomenetelmä
English keywords: forest planning; net present value; forest regeneration; cost of time delay; regeneration costs; final cutting age; regeneration method; zero percent interest rate
Abstract | View details | Full text in PDF | Author Info

Length of the regeneration period is a criterion commonly used for comparing different reforestation methods. The time factor should be evaluated using a realistic system for long-term planning. In this paper the preliminary evaluation is made by simplified calculations based on the development series. The slow regeneration method is assumed to be otherwise equal to the rapid one but it has a 5- or 10-years delay at the beginning, and the rotation is thus the final cutting age plus 5- or 10-years delay. Cost of the time delay is taken to be the difference in reforestation costs that makes the rapid and the slow methods equivalent. Calculations are made using zero costs for the slow method; but if the cost of the slow method increases, the critical cost difference decreases very slowly. The final cutting age and the regeneration method must be decided simultaneously. Therefore, the cost of the time delay is presented as a function of final cutting age. By maximizing the average annual revenue, rotation can be even increased if more rapid but more expensive regeneration method is used.

The PDF includes a summary in English.

  • Lappi, E-mail: jl@mm.unknown (email)
article id 5188, category Article
Eljas Pohtila, Tapani Pohjola. (1983). Vuosina 1970-1972 Lappiin perustetun aurattujen alueiden viljelykokeen tulokset. Silva Fennica vol. 17 no. 3 article id 5188. https://doi.org/10.14214/sf.a15171
English title: Results from the reforestation experiment on ploughed sites established in Finnish Lapland during 1970–1972.
Original keywords: kuusi; kylvö; mänty; istutus; maanmuokkaus; Lappi; uudistaminen; kuolleisuus; rauduskoivu; siperianlehtikuusi; auraus
English keywords: Pinus sylvestris; Norway spruce; Betula pendula; Picea abies; regeneration; soil preparation; Scots pine; silver birch; planting; ploughing; Lapland; mortality; Siberian larch; sowing; Larix sibirica
Abstract | View details | Full text in PDF | Author Info

The objective of the study was to compare different reforestation methods on ploughed areas in Finnish Lapland. Four species were compared: Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), silver birch (Betula pendula Roth) and Siberian larch (Larix sibirica Ledeb.). The experiments were established in different parts of Lapland on different types of sites in 1970–72.

In Scots pine there was a difference of 15 percentage points in survival of seedlings between the best and worst methods of regeneration. Containerized seedlings and paper pot seedlings had the best survival rates. In Norway spruce the respective difference between sowing and planting was about 20 percentage points. In favour of planting. The survival rate can be increased by about 20 percentage points by selecting the right tree species. The average height varied from 25 cm (the sowed Norway spruce) to 179 cm (the planted silver birch) after 10 growing seasons. The birch was planted at the most fertile sites only. The longer time passed from the afforestation the clearer was the effect of the local growing conditions on the development of the seedlings. The elevation of the site was one factor seemed to influence the success of the seedlings.

The PDF includes a summary in English.

  • Pohtila, E-mail: ep@mm.unknown (email)
  • Pohjola, E-mail: tp@mm.unknown
article id 5176, category Article
J. Lappi, A. Kotisaari, H. Smolander. (1983). Height relascope for regeneration surveys. Silva Fennica vol. 17 no. 1 article id 5176. https://doi.org/10.14214/sf.a15091
Keywords: sampling; forest mensuration; seedling stands; measuring instruments; regeneratoin surveys; seedling height; relascope
Abstract | View details | Full text in PDF | Author Info

The choice of sampling method is of prime importance when seeking relevant information about the height distribution and spatial arrangement of seedlings in the regeneration surveys. It is suggested that the size of sampling plots should depend on the height of the seedlings. Tall seedlings should be sampled from a larger area than short ones since tall seedlings are more important for the future development of the stand. We suggest principles for a technical development task to construct a device which is easy to use in practical regeneration surveys and by which sampling can be made proportional to plant height or any desired function of height.

The PDF includes a summary in Finnish.

  • Lappi, E-mail: jl@mm.unknown (email)
  • Kotisaari, E-mail: ak@mm.unknown
  • Smolander, E-mail: hs@mm.unknown
article id 5160, category Article
P. M. A. Tigerstedt. (1982). Metsäpuiden populaatiogenetiikka. Helsingissä 1981 pidetyn symposion tutkimusraportit. Silva Fennica vol. 16 no. 2 article id 5160. https://doi.org/10.14214/sf.a15075
English title: Population genetics of forest trees.
Original keywords: metsäntutkimus; metsänjalostus; kokoukset; siemenviljelmät; metsägenetiikka; populaatiogenetiikka; populaatiorakenne; sopeutuminen ympäristöolosuhteisiin; ekologinen erilaistuminen
English keywords: adaptation; seed orchards; population structure; population genetics; forest research; forest tree breeding; forest genetics; conference; ecological variation
Abstract | View details | Full text in PDF | Author Info

The publication comprises proceedings of a conference held in Helsinki in 1981. Forest tree populations are investigated for population genetic structure, mating systems, mechanisms of genetic adaptation and ecological adaptation. Methods and techniques used in population genetic research of forest trees are presented. Much concern is given to applications by means of forest tree breeding, particularly the seed orchard breeding technique. Generally, the application of population genetics in cultivated forests is discussed.

The PDF includes a preface and the presentations of the conference (25 short papers) in English, and a comprehensive summary of the themes of the conference in Finnish.

  • Tigerstedt, E-mail:
article id 5127, category Article
Simo Kaila, Juhani Päivänen. (1981). Metsämaanmuokkauksen suoritemäärät ja konekalusto vuosina 1976-1979. Silva Fennica vol. 15 no. 3 article id 5127. https://doi.org/10.14214/sf.a15068
English title: Forest soil cultivation areas and machinery in 1976–1979 in Finland.
Original keywords: maanmuokkaus; uudistaminen; metsäkoneet; lautasauraus; pyöräkoneet; telakoneet; auraus
English keywords: regeneration; soil preparation; disc plow; plowing; ploughing equipment; wheel tractors; crawler tractors
Abstract | View details | Full text in PDF | Author Info

The areas of soil cultivation in regeneration sites using different methods in 1976–1979 and the cultivation units in use in Finland in 1979 were studied by means of a questionnaire. Application of soil cultivation methods appears to have become strongly polarized: in Southern Finland disc plowing with wheel tractors are used, whilst in Northern Finland wing plowing with crawler tractors is the most popular method, each being practically the only alternative in the respective area.

The PDF includes a summary in English.

  • Kaila, E-mail: sk@mm.unknown (email)
  • Päivänen, E-mail: jp@mm.unknown
article id 5068, category Article
S. A. Petrov. (1980). Quantitative analysis of the effect of genotype and environment in forest tree populations. Silva Fennica vol. 14 no. 1 article id 5068. https://doi.org/10.14214/sf.a15009
Keywords: heritability; population structure; population genetics; genotype; Symposiums; intrapopulation variability; environment; quantitative characteristics
Abstract | View details | Full text in PDF | Author Info

The paper discusses the theoretical basis of quantitative analysis of the effect of genotype and environment in forest trees. Perhaps the main problem in the understanding of the laws of intrapopulation variability of the species of woody forest plants is the study of the structure of their populations. It may be characterized by a number of parameters. The intrapopulation variability of quantitative characteristics appears as a result of environmental and genetic factors, but to determine the relative weight of these factors in a concrete case is not easy. The study of the structure of a population by its quantitative characteristics has a wider task: to establish the relevance of the hereditary differences of the individuals of a population. Also, the differences caused by diverse growth conditions and how they are reflected in the level of general phenotypic variability of the quantitative characteristics in a given population has to be identified. The author gives examples of assessment of heritability in forest trees.

The PDF includes a summary in Finnish.

  • Petrov, E-mail: sp@mm.unknown (email)
article id 5058, category Article
Max Hagman. (1980). Suomalais-neuvostoliittolainen metsägenetiikan ja siemenhuollon symposiumi Punkaharjulla 17.–18.8.1978. Silva Fennica vol. 14 no. 1 article id 5058. https://doi.org/10.14214/sf.a14999
English title: Reports of the Finnish-Soviet symposium on forest genetics and forest tree seed production, Punkaharju, Finland, August 17-18. 1978.
Original keywords: metsänjalostus; Suomi; kokoukset; siemenviljely; Neuvostoliitto; seminaarit; genetiikka
English keywords: Finland; seed orchards; forest tree breeding; Soviet Union; USSR; symposium; forest genetics
Abstract | View details | Full text in PDF | Author Info

As a part of the scientific and technical cooperation between Finland and the USSR a symposium and an excursion on forest genetics and seed production was organized in Finland in August 1978. The symposium paper presented at Punkaharju are published here in order to bring them available for a wider audience.

The 12 symposium reports deal with the following subjects: Practical application of forest genetic research (A.I. Novoselceva), geographical variability and provenance transfer (E.P. Prokazin, M. Hagman, I. Etverk), variation in wood density (P. Velling), variation of flowering and seed crops in seed orchards (Y.P. Efimov), and natural stands (V. Koski), vegetative propagation (J. Niiranen), seed size effects and early test problems (J. Mikola), quantitative analysis of genotypic and environmental effects (S.A. Petrov), hormonal induction of flowering (O. Luukkanen) and x-ray photography analysis of the ageing of seeds during storage (M. Ryynänen).

The PDF includes a summary in Finnish.

  • Hagman, E-mail: mh@mm.unknown (email)
article id 5026, category Article
Alpo Enivaara. (1979). Pyynikin harjumännikön uudistaminen ja elvyttäminen. Silva Fennica vol. 13 no. 2 article id 5026. https://doi.org/10.14214/sf.a14881
English title: Regeneration and improvement of the Scots pine forest of Pyynikki esker in Southern Finland.
Original keywords: mänty; uudistaminen; seminaarit; maankäyttö; harju; Pyynikki; taajamametsät
English keywords: Pinus sylvestris; regeneration; Scots pine; urban forests; seminar; MAB; natural park
Abstract | View details | Full text in PDF | Author Info

Pyynikki is a unique natural park in the centre of the city of Tampere in Southern Finland. Currently, the forest of Pyynikki is losing its vigour because of aging and environmental factors. In 1977 a policy was designed for the regrowth of Scots pine (Pinus sylvestris L.) forest and improvement of the condition of the trees to avoid the situation that the whole pine forest (34 ha) would be regrown at one time. The period of regrowth of pine forest is 60 years. It is accomplished by cutting small openings, on which 4-year old potted pine saplings are planted. Birch will be planted only on two spots. The aim is that the forest scenery will be maintained as undamaged as possible. The condition of the growing forest will be improved by fertilization and thinning.

This paper was presented in the ‘Man and the Biosphere’ programme project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki.

The PDF includes a summary in English.

  • Enivaara, E-mail: ae@mm.unknown (email)
article id 5003, category Article
Hannu Saarenmaa. (1978). The occurrence of bark beetles (Col., Scolytidae) in a dead spruce stand flooded by beavers (Castor canadensis Kuhl.) . Silva Fennica vol. 12 no. 3 article id 5003. https://doi.org/10.14214/sf.a14857
Original keywords: kuusi; hyönteistuhot; tulva-alueet; kaarnakuoriaiset; kanadanmajava
English keywords: bark beetles; Norway spruce; Picea abies; Castor canadensis; insect damages; Trypodendron lineatum; flooded areas; Pityogenes chalcographus; Hylurgops palliatus; Ips typographus; Dryocetes autographus
Abstract | View details | Full text in PDF | Author Info

 

The aim of the study was to determine which kinds of insects had infected the Norway spruce (Picea abies (L.) H. Karst.) in different stands killed by flooding caused by beavers (Castor canadensis Kuhl), and if there was any danger that they would subsequently cause damage in the surrounding forests. The effect of tree diameter and certain stand characteristics on the fauna of dead trees are discussed. The occurrence of different insect combinations and qualifications for their coexistence were studied.

Pityogenes chalcographus L., Trypodendron lineatum O., Hylurgops palliatus Gyll. and Dryocetes autographus Ratz. occurred most abundantly. 20 phloem or wood boring species were observed in 5 regular succession types. Secondary species occurred in a virgin stand while Ips typographus L. was found at the edge of a felling area. Owing to the flooding, species preferring moist conditions were abundant. In this case damages had not spread to the surrounding forests which, however, might be possible under certain conditions.

The PDF includes a summary in English.

  • Saarenmaa, E-mail: hs@mm.unknown (email)
article id 4984, category Article
Jyrki Raulo. (1978). Forestation chain for birch (Betula pendula Roth) in Finland. Silva Fennica vol. 12 no. 1 article id 4984. https://doi.org/10.14214/sf.a14838
Keywords: forest management; Betula pendula; regeneration; silver birch; Finland
Abstract | View details | Full text in PDF | Author Info

During the 1970’s an average of 4 million Betula pendula (Roth) seedlings have been planted annually in Finland. The activities connected with the planting of this tree species, the selection of forestation sites, site preparation, planting out the seedlings and follow-up work on the forestation sites are briefly reviewed in the article. The manuscript is based on the studies into the breeding, seedling production and planting techniques of B. pendula started by the Finnish Forest Research Institute already in 1960’s, as well as on practical observations made at the planting sites. A list of some of the Finnish studies concerning B. pendula which have been published in English and studies with a summary in English is included.

The PDF includes a summary in Finnish.

  • Raulo, E-mail: jr@mm.unknown (email)
article id 4962, category Article
Matti Keltikangas, Kustaa Seppälä. (1977). Ojitusalueiden hieskoivikoiden kasvatus taloudellisena vaihtoehtona. Silva Fennica vol. 11 no. 1 article id 4962. https://doi.org/10.14214/sf.a14813
English title: The economics of growing downy birch stands on drained peatlands in Finland.
Original keywords: kannattavuus; mänty; metsän uudistaminen; ojitetut suot; hieskoivu; uudistamiskustannukset
English keywords: Pinus sylvestris; regeneration; Betula pubescens; Scots pine; downy birch; profitability
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to determine under what conditions and with what premises the growing of Betula pubescens Ehrh. is an economically competitive alternative to the growing of Scots pine (Pinus sylvestris L.) in drained peatlands. The basic material consisted of all drainage projects in Ostrobothnia in Western Finland in 1937–38 and 1957–59, according to the archives of the Central Board of Forestry Tapio, including such areas that were at least moderately fertile and had birch dominated young stands or no tree cover. A total of 202 sample plots were measured.

According to the results, the discounted timber yield of the thinned B. pubescens stands is about 10% greater than that of untreated stands. The removing of birch seedlings and the subsequent growing of fully stocked Scots pine is more profitable than growing B. pubescens stands only if the establishment and subsequent development of the pine stand involve no costs. If the site in question is a fertile open drained peatland, establishment of a pine stand is obviously a better financial proposition than a naturally regenerated birch stand. However, if there is already a fully stocked young birch stand on the site, it is more economical to let it grow using a shortish rotation time.

The PDF includes a summary in English.

  • Keltikangas, E-mail: mk@mm.unknown (email)
  • Seppälä, E-mail: ks@mm.unknown
article id 4888, category Article
Olavi Luukkanen. (1973). Havaintoja kuusen vapaapölytysjälkeläistöjen ja männyn metsikköalkuperien CO2-aineenvaihdunnasta. Silva Fennica vol. 7 no. 4 article id 4888. https://doi.org/10.14214/sf.a14726
English title: Observations on CO2 exchange in open pollinated progenies of Norway spruce and provenances of Scots pine.
Original keywords: kuusi; mänty; metsänjalostus; pluspuu; fotosynteesi; geneettinen muuntelu; pimeähengitys; yhteyttämisteho
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; tree breeding; photosynthesis capacity; genetic variance; dark respiration
Abstract | View details | Full text in PDF | Author Info

Photosynthesis and dark respiration in five families of autochtonous Norway spruce (Picea abies (L.) H. Karst.) and in seedlings from twenty Finnish stands of Scots pine (Pinus sylvestris L.) were investigated in constant environmental conditions. Values of CO2 exchange were compared with the height growth and weight of seedlings in Norway spruce and with the weight alone in Scots pine. No statistically significant differences were found in CO2 exchange among progenies or stands. Photosynthetic efficiency and photosynthetic capacity showed a positive correlation both in spruce and in pine. Growth and net photosynthetic capacity were linearly and positively correlated in pine. Spruce and a higher light compensation point than pine. The use of an open IRGA system with several simultaneous measurements and the trap-type cuvette construction in genetic work are discussed.

The PDF includes a summary in English.

  • Luukkanen, E-mail: ol@mm.unknown (email)
article id 4876, category Article
Tapio Lehtiniemi, Juhani Sarasto. (1973). Kokemuksia rauduksen istutuksesta ojitetuille soille. Silva Fennica vol. 7 no. 1 article id 4876. https://doi.org/10.14214/sf.a14706
English title: Betula verrucosa plantations on peat.
Original keywords: taimet; turvemaat; uudistaminen; ojitetut suot; kuolleisuus; rauduskoivu; ravinnetasapaino
English keywords: Betula pendula; regeneration; drained peatlands; planting; nutrient deficiency; mortality; seedlings; Betula verrucosa; Godronia multispora
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to assess whether two-year old Betula verrucosa Ehrh. (now Betula pendula Roth.) transplants can be used in afforestation of drained peatlands and what factors affect the development of the young trees. The seedlings were planted in 1967. The site was repair planted next spring due to mortality caused by a undefined fungal disease, and the plantations were fertilized with NPK fertilizer (soil application. The seedlings were measured twice a year until the autumn 1970.

Only 28% of the original transplants, and 73.4% of the repair plantations were alive in 1970. In some cases, fertilization improved the results, while in others it was detrimental to the trees or had no effect on survival. According to peat analysis, the poor survival and development of the plants could be due to the too high ratios of N/Ca and N/P. Stunted or dead trees displayed often necrosis caused by Godronia multispora. According to the experiences, Betula verrucosa plantations are inferior to those obtained with Scots pine (Pinus sylvestris L.). In addition, the results indicate that in old draining areas calcium and phosphorus are often too low in comparison to nitrogen.

The PDF includes a summary in English.

  • Lehtiniemi, E-mail: tl@mm.unknown (email)
  • Sarasto, E-mail: js@mm.unknown
article id 4869, category Article
Ole Oskarsson, P. M. A. Tigerstedt. (1972). Metsänjalostuksen mahdollisuudet II. Silva Fennica vol. 6 no. 3 article id 4869. https://doi.org/10.14214/sf.a14672
English title: The possibilities in forest tree breeding II. Selection differences and genetic gains in selected seed stands of Scots pine.
Original keywords: mänty; metsänjalostus; tilavuuskasvu; valintahyöty; siemenkeräysmetsät; fenotyyppi; kuutiokasvu
English keywords: Pinus sylvestris; Scots pine; volume growth; genetic gain; forest tree breeding; seed stands; phenotype
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to estimate the genetic gain of volume growth in Scots pine (Pinus sylvestris L.) selected seed stands. To obtain highest possible accuracy, the estimations are based on a large statistical material comprising 197 separate seed stands. It is concluded that the genetic gain of volume growth ranges between 7.4–15.0%. Unwanted pollen contaminations may, however, in the worst case halve this genetic gain.

The PDF includes a summary in English.

  • Oskarsson, E-mail: oo@mm.unknown (email)
  • Tigerstedt, E-mail: pt@mm.unknown
article id 4868, category Article
Mikko Tormilainen. (1972). Havaintoja Oitin siemenviljelyksen mäntykloonien kukinnasta ja käpysadosta. Silva Fennica vol. 6 no. 2 article id 4868. https://doi.org/10.14214/sf.a14671
English title: Studies of flowering and cone crop in a seed orchard of Scots pine.
Original keywords: Etelä-Suomi; mänty; kloonit; siemenviljelmä; siemenviljely; kukinta; käpysato; geneettinen vaihtelu
English keywords: Pinus sylvestris; Scots pine; flowering; genetic variation; seed orchards; clones; Southern Finland; cone production
Abstract | View details | Full text in PDF | Author Info

Male and female flowering, cone crop, and some vegetative characteristics were studied in grafts 10 to 16 years of age in a clonal seed orchard of Scots pine (Pinus sylvestris L.). Genetic variation was found between clones in flowering as well as in cone production. Clone evaluation resulted in similar classifications of clones in different years. A regression analysis showed that crown size clearly increased but previous height growth slightly decreased flowering and cone production. The percentage of pollinated female strobili did not differ between clones.

The PDF includes a summary in English.

  • Tormilainen, E-mail: mt@mm.unknown (email)
article id 4863, category Article
Olavi Luukkanen. (1972). Metsäpuiden fotosynteesin geneettinen vaihtelu. Silva Fennica vol. 6 no. 2 article id 4863. https://doi.org/10.14214/sf.a14666
English title: Genetic variation of photosynthesis in forest trees.
Original keywords: fotosynteesi; geneettinen muuntelu; hengitys; fotorespiraatio; poppeli; hiilidioksidi; kaasuaineenvaihdunta
English keywords: photosynthesis; carbon dioxide; photorespiration; CO2 exhange
Abstract | View details | Full text in PDF | Author Info

In the literature review the current status of information on the genetic variation of CO2 exchange and some reviews and investigations on this subject are listed. Photorespiration is separately discussed and unpublished data of an electron microscope study of poplar leaf microbodies are presented.

Considerable genetic inter- and intraspecific variation is found in several characteristics that affect CO2 exchange in trees. Photosynthesis in young trees does not correlate well with growth through the whole rotation cycle. A special interest has been shown to marginal environmental conditions (e.g. water deficit, low temperature, and low light intensity), as opposed to optimal conditions often employed in laboratory studies of CO2 exchange in trees.

In an unpublished poplar studies by the author et.al. a preliminary experiment with poplar clones showed variation in the CO2 competition point. This variation was negatively correlated with the photosynthesis efficiency of these clones.

The PDF includes a summary in English.

  • Luukkanen, E-mail: ol@mm.unknown (email)
article id 4832, category Article
Paavo Yli-Vakkuri, Pentti K. Räsänen. (1971). Siementen peittämisen ja kylvökohdan polkaisun vaikutus männyn ruutukylvön tulokseen. Silva Fennica vol. 5 no. 1 article id 4832. https://doi.org/10.14214/sf.a14621
English title: The influence of covering and tramping the seeds into the soil on the success of spot sowing of Scots pine.
Original keywords: kylvö; mänty; metsänviljely; taimettuminen; itäminen; kylvösyvyys; siementen suojaus; ruutukylvö
English keywords: Pinus sylvestris; germination; Scots pine; sowing; artificial regeneration; covering of the seeds; stocking with seedlings
Abstract | View details | Full text in PDF | Author Info

This paper reports spot sowing experiments of Scots pine (Pinus sylvestris L.). The seeds were either covered with coarse sand, tramped in the substrate or sowed without any covering, 30 seeds in each treatment in 70 replications. The site was of Vaccinium type with sandy soil. The germination percentage was 81 and 91 on the respective years. The development of seedlings was observed for 3–4 years.

The results indicate that both tramping and covering the seeds to some extent increased the number of seedlings and improved the early development. The highest numbers of seedlings were recorded in the first growing season, after which there was 23 seedlings/100 seeds in the uncovered spots, 27 seedlings in the covered spots and 31 seedlings in the tramped spots in the experiment sowed in 1965.

Mortality of the seedlings was highest between the first and second growing season, and empty spots increased with the time. There was no difference in mortality between the sowing methods, but the number of seedlings after first growing season affected the result. Under favourable conditions four seedlings per spot seemed enough to secure the survival of minimum one seedling per spot during the three first growing seasons. In poor conditions seven seedlings was needed.

The PDF includes a summary in English.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
  • Räsänen, E-mail: pr@mm.unknown
article id 4816, category Article
P. M. A. Tigerstedt, Eero Malmivaara. (1970). Metsänjalostuksen mahdollisuudet I.Pluspuiden valintaero ja siemenviljelysten valintahyöty. Silva Fennica vol. 4 no. 2 article id 4816. https://doi.org/10.14214/sf.a14605
English title: The possibilities in forest tree breeding. I Selection differential of plus trees and genetic gain in seed orchards in Finland.
Original keywords: mänty; metsänjalostus; siemenviljelmät; pluspuut; valintahyöty; periytyvyys; vieraspölytys
English keywords: Pinus sylvestris; Scots pine; tree breeding; seed orchards; genetic gain; heredity; selection differential; foreign pollen sources
Abstract | View details | Full text in PDF | Author Info

An attempt was made to estimate critically the genetic gain in clonal seed orchards of Scots pine (Pinus sylvestris L.) in Finland. The selection differential of Scots pine and Norway spruce (Picea abies (L.) H. Karst.) is calculated on the basis of filed information on selected plus trees which has been kept by the genetic register at the Finnish Forest Research Institute. The differentials were computed as realized differences in height between plus-trees and normal stand characteristics on respectively site class and as a function of age.

The genetic gain in height growth of Pinus sylvestris was computed on the basis of information on selection differential and heritability. This genetic gain is between 2.6–4.4% provided there is no pollen contamination from unknown sources outside the seed orchard. The genetic gain of volume growth in Scots pine is about 7–15%, provided there is no pollen contamination in the seed orchard. However, according to investigations, there is invariably some pollen contamination in this kind of seed orchards. The contamination decreases to about 30–50% as the orchard matures and starts to produce endemic pollen. If the pollination would be entirely due to foreign pollen sources, the mathematically calculated genetic gain would be 3.5–7.5%.

The PDF includes a summary in English.

  • Tigerstedt, E-mail: pt@mm.unknown (email)
  • Malmivaara, E-mail: em@mm.unknown
article id 4784, category Article
Matti Leikola, Pentti Pylkkö. (1969). Verhopuuston tiheyden vaikutus metsikön minimilämpötiloihin hallaöinä. Silva Fennica vol. 3 no. 1 article id 4784. https://doi.org/10.14214/sf.a14570
English title: Influence of stand density on the minimum temperatures during frost nights.
Original keywords: kuusi; tiheys; koivu; uudistuminen; lämpötila; suojapuusto; halla
English keywords: Norway spruce; Picea abies; regeneration; Betula pubescens; temperature; stand density; white birch; shelter stand; frost
Abstract | View details | Full text in PDF | Author Info

The objective of this investigation was to study the influence of stand density of white birch (Betula pubescens Ehrl.) on the minimum temperatures in the stand during the growing season, and the actual minimum temperatures of the leading shoot of Norway spruce (Picea abies (L.) H. Karst.) seedlings growing in the open. The 40-year-old uniform white birch stand was situated in 142 m above the sea level in Southern Finland. The stand was treated with thinnings of three different densities in 1961.

Air temperature was recorded in four sample plots at heights of 0.1 m, 0.5 m, 1.0 m, 2 m and 4 m. In the stand of moderate density, temperatures were measured at heights of 6.0 m, and in the stand of full density at 6.0 m, 8.0 m and 10.0 m.

The temperature differences between stands of various densities proved to be rather small. Especially the thinnest stand differed very little from the open area. The soil surface has in all cases been warm compared with the higher air layers indicating meadow-fog-type by Geier (1965). On cloudy or windy weather all the temperature profiles in the various stands resembled each other. The difference between the air temperature and temperature of the spruce shoot was greatest at midnight and decreased steadily thereafter.

The problem in using shelter stands for spruce regeneration areas is that optimum shelter stand density is difficult to define. Already a thin shelter stand causes drawbacks to the young seedlings, but in order to be effective enough against early frosts, the shelter stand should be comparatively dense.

The PDF includes a summary in English.

  • Leikola, E-mail: ml@mm.unknown (email)
  • Pylkkö, E-mail: pp@mm.unknown
article id 4769, category Article
Paavo Yli-Vakkuri, Aimo Autio, Juhani Vehkaoja. (1968). Päätehakkuun ja metsänviljelyn välinen aika. Silva Fennica vol. 2 no. 3 article id 4769. https://doi.org/10.14214/sf.a14554
English title: Time lag between final cutting and regeneration.
Original keywords: kylvö; metsänviljely; istutus; uudistaminen; uudistusaika; istutusrästit; viivästys
English keywords: planting; final felling; sowing; artificial regeneration; seeding; time lag
Abstract | View details | Full text in PDF | Author Info

The time interval between final felling and plantation means a waste of time and thus a production loss, and may lead to lush growth of ground cover and hardwood sprouts, which increases expenses in forest management. The objective of this study was to determine the length of time between final felling and artificial regeneration in private forests in the forest districts of Uusimaa-Häme in Southern Finland and Pohjois-Häme in Central Finland. The material consists of a sample of 150 plans of the 952 cutting and regeneration plans in the district of Uusimaa-Häme and a sample of 140 plans of the 1,102 plans in Pohjois-Häme.

The time lag between final cutting and seeding or planting was on average 1.4 years in Pohjois-Häme district and 0.7 years in Uusimaa-Häme. In the latter district, 56% of the logged area was regenerated in the spring immediately following the cutting, and 84% not later than in the second spring. In Pohjois-Häme, 29% of the harvested area was regenerated immediately in the first spring following cutting, and 79% not later than in the third spring following cutting.

In Pohjois-Häme, the interval was shortest in the smallest forest holdings, and longest in the largest holdings with the largest regeneration areas. The length seems to depend mainly on the size of the regeneration area. In Uusimaa-Häme district, the interval was shortest in the smallest holdings, rather short in the largest, and longest in the intermediate-size forest properties. Seeding with Scots pine (Pinus sylvestris L.) was used in almost all regeneration areas.

The forest owners had mainly carried out the regeneration work themselves. In the Pohjois-Häme area, the interval was shorter when the district forestry board regenerated the area. 35% of the regenerated areas had required supplementary planting in Pohjois-Häme, and 47% in the Uusimaa-Häme area. Supplementary planting was more common in areas regenerated later after the cutting. In Pohjois-Häme, according to the reports of the forest owners, 75% of the regenerated areas required tending during the first three years, in Uusimaa-Häme, 80%.

The PDF includes a summary in English.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
  • Autio, E-mail: aa@mm.unknown
  • Vehkaoja, E-mail: jv@mm.unknown
article id 4731, category Article
Leo Heikurainen, Juhani Päivänen, Kustaa Seppälä. (1966). Koetuloksia männyn kylvöstä ja istutuksesta ojitetuilla soilla. Silva Fennica no. 119 article id 4731. https://doi.org/10.14214/sf.a14289
English title: Scots pine seeding and planting on drained peat soils.
Original keywords: kylvö; mänty; istutus; uudistaminen; lannoitus; turvekankaat; ojitetut suot
English keywords: Pinus sylvestris; fertilization; regeneration; Scots pine; planting; sowing; artificial regeneration; seeding
Abstract | View details | Full text in PDF | Author Info

This paper describes the preliminary results of Scots pine (Pinus sylvestris L.) seeding and planting trials on drained peat soils.

The results showed that a perpared peat surface was a better surface for seeding than the unprepared one. Planting of 2+1-year seedlings succeeded better than planting 1-year seedlings. Planting on the turf gave better survival than planting on the unprepared soil surface. The whole growing season was suitable time for planting Scots pine seedlings except May when the peat soil under the surface was still frozen.

Using fertilizers in connection with planting was surveyed in two ways. Mortality of seedlings increased when they were top-dressed with NPK fertilizer. Using a so-called spot fertilizing with several combinations of fertilizers resulted in K and N tending to increase the mortality of seedlings, but P decreasing mortality.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@mm.unknown (email)
  • Päivänen, E-mail: jp@mm.unknown
  • Seppälä, E-mail: ks@mm.unknown
article id 4723, category Article
Toivo Matilainen. (1965). Kasvutappiosta ja sen määrittämisestä Etelä-Suomen talousmetsissä. Silva Fennica no. 117 article id 4723. https://doi.org/10.14214/sf.a14281
English title: The increment loss and its determination in economically exploited forests in Southern Finland.
Original keywords: Etelä-Suomi; menetelmät; vajaatuottoiset metsät; kasvutappiot; uudistaminen
English keywords: regeneration; Southern Finland; methods; under-productive forests; deficient stock volume; increment loss
Abstract | View details | Full text in PDF | Author Info

The present study is an attempt to clarify the decrease in growth, or the increment loss, caused by sudden reduction of growth of the growing stock below a certain level, and to find a method for its determination. Increment loss is defined as a decrease in growth during the rotation due to a deficient stock volume. The material consists of Koivisto’s yield tables for repeatedly thinned stands in Southern Finland, and the results of the Third National Forest Inventory concerning the mean volume and increment in the productive sites.

For the calculation of increment loss three formulae were constructed where the increment loss is calculated 1) as the difference between the removal by thinnings in normally developed stands during a time equal with the period of deficient stock and the suddenly removed stock, 2) according to the compound interest calculation principle as the sum of the differences which are obtained by subtracting from the removal in each thinning during the period of deficient stock its initial value, and 3) as the straight interest of the stock deficiency during the period of deficient stock.

According to the calculations, the increment loss is greatest in stands to be grown, viz. 50 m3 solid measure excluding bark per hectare tended Norway spruce stands on Oxalis-Myrtillus type sites at 40% deficiency below minimum stock. In stands to be regenerated the losses are, too, greatest in the similar stands. It exceeds 200 m3/ha when stands younger than 50 years have to been regenerated and the removal amounts to 50% of the stock. In stands to be regenerated the increment loss for spruce, due to the slow initial development by the species, is greater than for Scots pine and birch. The loss is the same at different period of age if the relative deficiency of the stock is of equal size.

According to the study, each stand has a characteristic variation in the increment loss which depends mainly on the relative degree of deficiency from the minimum stock. The formulae and methods can be used to determine the increment loss in average and better stands in Southern Finland when the stock suddenly decreases.

The PDF includes a summary in English.

  • Matilainen, E-mail: tm@mm.unknown (email)
article id 4669, category Article
V. A. Kolehmainen. (1957). Vehkatallinmaa. Silva Fennica no. 90 article id 4669. https://doi.org/10.14214/sf.a9116
English title: Vehkatallinmaa, a successful reforestation area in Central Finland.
Original keywords: luontainen uudistuminen; kylvö; metsitys; metsäpalot
English keywords: regeneration; natural regeneration; forest fire; sowing
Abstract | View details | Full text in PDF | Author Info

In 1933, forest fire caused by locomotive sparkle burned about 600 hectares of forest in a forest district named Vehkatallinmaa, in Central Finland. In 1934–36, the burned area was reforested, using different sowing and planting methods. At the same time, areas with poor runoff were drained. The results from reforestation throughout the area have been good. Also, natural regeneration of coniferous trees, especially Scots pine (Pinus sylvestris L.) has occurred. Even deciduous trees, especially birch (Betula sp.), have regenerated naturally in the area. The forests are an evidence of the adaptability of broadcast sowing on snow crust as a method of reproduction.

The PDF includes a summary in English.

  • Kolehmainen, E-mail: vk@mm.unknown (email)
article id 4644, category Article
Vilho Antero Kolehmainen. (1955). Havaintoja kulotuksen merkityksestä metsiemme uudistamisessa. Silva Fennica no. 85 article id 4644. https://doi.org/10.14214/sf.a9106
English title: Effect of prescribed burning in the forest regeneration.
Original keywords: luontainen uudistaminen; kulotus; metsänuudistaminen; taimettuminen; siemenpuu
English keywords: Pinus sylvestris; Norway spruce; Picea abies; natural regeneration; Scots pine; Betula sp.; seed trees; prescribed burning
Abstract | View details | Full text in PDF | Author Info

Prescribed burning has reported to avail forest regeneration, for instance, by releasing nutrients for the use of seedlings, changing the pH of the soil and decreasing competition of ground vegetation. The aim of the study was to find out if the effects could be verified. Sample plots were measured in the experimental area of Tuomarniemi, in Central Finland, both in previously burned and untreated seedling stands and young forests. The main species in the sample plots was Scots pine (Pinus sylvestris L.).

According to the results, prescribed burning prepares the soil for regeneration. Germination percentage of the seeds is higher on the burned soil. All the species, Scots pine, Norway spruce (Picea abies (L.) Karst.) and birch species (Betula sp.) grow faster. Prescribed burning increases the amount of birch seedlings by improving its regeneration compared to unburned sites. The seed trees survive burning better if they are tall and have short crown, and have thick bark. In general, prescribed burning improves regeneration in seed tree stands.

The article includes a summary in German.

  • Kolehmainen, E-mail: vk@mm.unknown (email)
article id 4638, category Article
Risto Sarvas. (1953). Ohjeita pluspuiden valitsemista ja ilmoittamista varten. Silva Fennica no. 80 article id 4638. https://doi.org/10.14214/sf.a14054
English title: Instruction for the selection and registration of plus trees.
Original keywords: metsäopetus; jatkokoulutus; metsänuudistaminen; siementuotanto; metsänjalostus; pluspuu
English keywords: regeneration; selection; breeding; seed production; forest education
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes principles of breeding of forest trees and the selection of fast growing, healthy and qualitatively good trees, named plus trees, for seed production in Finland.

  • Sarvas, E-mail: rs@mm.unknown (email)
article id 4637, category Article
Eero Paavola. (1953). Selostus kenttäkokeista, jotka koskivat eräiden kemiallisten aineiden käyttömahdollisuuksia metsänkylvössä. Silva Fennica no. 80 article id 4637. https://doi.org/10.14214/sf.a14053
English title: Review of field experiments on the fitness of certain chemicals for use at seeding.
Original keywords: metsäopetus; kylvö; metsänviljely; jatkokoulutus; metsänuudistaminen; heinäntorjunta; herbisidit; torjunta-aineet
English keywords: ground vegetation; herbicides; forest regeneration; forest education; seeding
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes a field experiment on the use of herbicides to prevent growth of ground vegetation in cutting areas before sowing. The study suggests that the chemicals used in the experiment were not effective enough to prevent growth of ground vegetation in the more fertile lands, but were effective in poorer lands. However, the treatment affected also growth of tree seedlings.

  • Paavola, E-mail: ep@mm.unknown (email)
article id 4636, category Article
Tauno Hautamäki. (1953). Metsämaan laikutuksen koneellistamiskokeiluista. Silva Fennica no. 80 article id 4636. https://doi.org/10.14214/sf.a14052
English title: Mechanization of ground preparation.
Original keywords: metsäopetus; jatkokoulutus; maanmuokkaus; metsänuudistaminen; koneellistaminen; laikutus
English keywords: regeneration; soil preparation; mechanization; scalping; forest education
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

Soil preparation improves formation of seedlings in natural regeneration sites. This presentation describes mechanization of the work using four different machines. According to the study, the effectiveness and quality of the work has improved compared to the earlier machines, and the method is becoming a competitive alternative to slash burning.

  • Hautamäki, E-mail: th@mm.unknown (email)
article id 4628, category Article
Gustaf Sirén. (1952). Havaintoja Peräpohjolan valtion mailla vuosina 1948-50 suoritetuista männyn kylvöistä. Silva Fennica no. 78 article id 4628. https://doi.org/10.14214/sf.a9100
English title: Observations on stands of Scots pine sown in state forests in Peräpohjola in northern Finland in 1948-50.
Original keywords: Pohjois-Suomi; valtionmetsät; kylvö; mänty; metsänviljely; Peräpohjola; uudistuminen
English keywords: Pinus sylvestris; regeneration; Scots pine; northern Finland; state forests; sowing
Abstract | View details | Full text in PDF | Author Info

The most common way to artificially regenerate cutting areas in Northern Finland has been sowing, which has, however, often given poor results. The aim of the study was to assess the success rate of sowing and study the causes of poor regeneration.

An inventory was made of 28 areas on Empetrum-Myrtillus and Hylocomnium-Myrtillus type sites sown with Scots pine (Pinus sylvestris L.) seeds in 1948-1950. In addition, to study the effect of substrata, a sowing experiment was established. According to the inventory, regeneration failed completely in 8 and partially in 6 of the 28 sown areas. Factors that explained the poor regeneration included unfavourable weather conditions in 1948-1952, insufficient clearing of sowing spot especially when the humus layer was thick, and insect damage by Otiorynchus dubius weevil.

The article includes a summary in English.

  • Sirén, E-mail: gs@mm.unknown (email)
article id 4578, category Article
Sakari Saarnijoki. (1942). Jalavan esiintymisestä Pyhäjärven, Kokemäenjoen vesistön keskusjärven tulvarannoilla. Silva Fennica no. 58 article id 4578. https://doi.org/10.14214/sf.a9082
English title: Distribution of European white elm in flooded shores of the central lake of Pyhäjärvi and Kokemäenjoki water system.
Original keywords: levinneisyys; jalava; kynäjalava; vuorijalava; rantametsä; tulva-alueet; Ulmus glabra; Ulmus laevis; Ulmus montana; uudistuminen
English keywords: regeneration; distribution; elm; European white elm; coastal forests; flood plains
Abstract | View details | Full text in PDF | Author Info

Distribution of European white elm (Ulmus laevis Pallas) is on its northernmost border in Pyhäjärvi and Kokemäenjoki area. This survey describes distribution of European white elm in the flooded shores of the central lake of Pyhäjärvi and Kokemäenjoki river water system.

Both Ulmus laevis and U. montana (now U. Glabra Hudson) can be found in the area, but most of the elms qrowing in thea area are U. laevis. U. laevis occurs around the lake in two separate areas, almost entirely in flooded shores of the lake. Regeneration of elm from seeds was limited on a narrow belt on the higher part of the flooded shore. Consequently, U. laevis can be found as zones around the lake, created by the changes in water level of the lake. The trees are judged to be native for the area.

The article includes an abstract in German.

  • Saarnijoki, E-mail: ss@mm.unknown (email)
article id 4568, category Article
Atri S. Arimo. (1939). Paloalojen metsittämisestä. Silva Fennica no. 52 article id 4568. https://doi.org/10.14214/sf.a13975
English title: Forest regenration of burned areas.
Original keywords: metsäopetus; kylvö; metsänviljely; metsänhoitajien jatkokurssit; kulotus; metsäpalo; jatkokoulutus; metsänuudistaminen; kulo
English keywords: regeneration; planting; forest fire; forest education; sowing; professional development courses
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 52 includes presentations held in professional development courses, arranged for foresters working in public administration in 1938. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes preparation and forest regeneration methods of a burned area.

  • Arimo, E-mail: aa@mm.unknown (email)
article id 4559, category Article
A. A. Räsänen. (1939). Metsien uudistamisesta Perä-Pohjolassa. Silva Fennica no. 52 article id 4559. https://doi.org/10.14214/sf.a13966
English title: Forest regeneration in Northern Finland.
Original keywords: hakkuut; metsäopetus; metsänviljely; metsänhoitajien jatkokurssit; jatkokoulutus; maanmuokkaus; metsänuudistaminen; Lappi; yli-ikäiset metsät
English keywords: forest management; Norway spruce; Picea abies; regeneration; fellings; forest education; professional development courses
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 52 includes presentations held in professional development courses, arranged for foresters working in public administration in 1938. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes the state of forests in Northern Finland, and suggests that fellings are targeted at the oldest forests until the over-presented over-aged forest are harvested. The preferred regeneration method is natural regeneration in most forest types.

  • Räsänen, E-mail: ar@mm.unknown (email)
article id 4558, category Article
Olli Heikinheimo. (1939). Kokemuksia paksusammaltyypin metsien käsittelystä. Silva Fennica no. 52 article id 4558. https://doi.org/10.14214/sf.a13965
English title: Experiences in forest management of Hylocomnium-Myrtillus type forests in Northern Finland.
Original keywords: hakkuut; metsänhoito; metsäopetus; metsänhoitajien jatkokurssit; jatkokoulutus; metsänuudistaminen; paksusammalkuusikko; Peräpohjola; Lappi; siementuotanto
English keywords: Norway spruce; Picea abies; regeneration; Lapland; seed production; fellings; forest education; professional development courses; Hylocomnium-Myrtillus type
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 52 includes presentations held in professional development courses, arranged for foresters working in public administration in 1938. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes a study of forest management practices suitable for in Hylocomnium-Myrtillus site type forests, typical for Northern Finland. A special problem for the forest site type is poor regeneration due weak seed production of Norway spruce (Picea abies L. Karst.) and thick moss layer.

  • Heikinheimo, E-mail: oh@mm.unknown (email)
article id 4571, category Article
Tauno Lampimäki. (1939). Nautakarjan laiduntamisesta metsämailla. Silva Fennica no. 50 article id 4571. https://doi.org/10.14214/sf.a9074
English title: Grazing of cattle in forest land.
Original keywords: metsätalous; taimettuminen; metsänuudistuminen; laiduntaminen; laitumet; karja; karjatalous; pintakasvillisuus; taimet; taimituhot; metsälaidun
English keywords: regeneration; forestry; ground vegetation; tree seedlings; grazing; cattle; animal husbandry; woodland pasture
Abstract | View details | Full text in PDF | Author Info

Finland has a long tradition of grazing cattle in the forests and common land. There are also reports of degradation of forests by grazing already in 1600th century. The aim of the survey was to study which positive and negative effects grazing has in forests.

The study concludes that grazing has caused considerable economic losses through damages to forests. In addition, woodland pastures cannot give the yields required in modern animal husbandry. The quality of woodland pastures have decreased after the woodlands used in slash and burn culture have become wooded.

Grazing has also some positive effects to forests. It increases the diversity of vegetation in the woodland pastures and spreads species to new areas. This is supported by the lists of species found in different woodland pastures. Cattle destroy large grasses like Calamagrostis, which may avail growth of tree seedlings in the pastures. Grazing can also prepare the site for tree seedlings. On the other hand, prolonged grazing destroys tree seedlings and prevents regeneration.

The article includes a German summary.

  • Lampimäki, E-mail: tl@mm.unknown (email)
article id 4543, category Article
Erkki Laitakari. (1938). Metsän uudistamisesta laihoilla kangasmailla. Silva Fennica no. 46 article id 4543. https://doi.org/10.14214/sf.a13952
English title: Forest regeneration on poor forest sites.
Original keywords: luontainen uudistuminen; kuiva kangas; metsäopetus; metsänhoitajien jatkokurssit; kulotus; kuivahko kangas; kasvupaikka; metsänuudistuminen; uudistushakkuu
English keywords: natural regeneration; forest regeneration; forest education; professional development courses; broadcast burning; dry upland forest site; dryish upland forest site; regeneration felling
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes forest regeneration on poor forest sites.

  • Laitakari, E-mail: el@mm.unknown (email)
article id 4542, category Article
Erkki Laitakari. (1938). Eräitä metsän uudistamisessa huomioon otettavia näkökohtia. Silva Fennica no. 46 article id 4542. https://doi.org/10.14214/sf.a13951
English title: Forest regeneration.
Original keywords: metsäopetus; metsänviljely; metsänhoitajien jatkokurssit; luontainen uudistaminen; metsänuudistaminen
English keywords: natural regeneration; planting; forest education; professional development courses; articifial regeneration
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes factors that should be taken into account in forest regeneration. 

  • Laitakari, E-mail: el@mm.unknown (email)
article id 4536, category Article
V. K. Ahola. (1938). Metsän uudistumisen tarkkailusta kovilla metsämailla ja ojitetuilla soilla sekä ojien tarkkailusta. Silva Fennica no. 46 article id 4536. https://doi.org/10.14214/sf.a13945
English title: Inspection of regeneration of forests in mineral soil forests and drained peatlands and checking of ditches.
Original keywords: valtionmetsät; ojitus; metsäopetus; metsänviljely; metsänhoitajien jatkokurssit; luontainen uudistaminen; suot; hoitoalueet; taimettuminen; taimikko; ojitusalueet
English keywords: natural regeneration; drained peatlands; peatlands; seedling stands; forest education; state forests; artificial regeneration; professional development courses; districts
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes inspection of forest regeneration of mineral soil forest types and drained peatlands, and inspection of ditches. 

  • Ahola, E-mail: va@mm.unknown (email)
article id 4534, category Article
Martti Tertti. (1938). Hakkausalan raivaamisesta. Silva Fennica no. 46 article id 4534. https://doi.org/10.14214/sf.a13943
English title: Clearing of a felling area.
Original keywords: hakkuut; metsäopetus; metsänhoitajien jatkokurssit; metsänraivaus; hakkuuala; metsänuudistaminen; raivaus; alikasvos
English keywords: regeneration; fellings; forest education; professional development courses; cutting area; clearing of felling areas; undergrowth
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 46 includes presentations held in professional development coursesarranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administrationespecially in regional levelThe education was arranged by Forest Service. 
This presentation describes clearing of felling areas. 

  • Tertti, E-mail: mt@mm.unknown (email)
article id 4530, category Article
O. J. Lukkala. (1938). Ojitettujen soiden metsittämisestä. Silva Fennica no. 46 article id 4530. https://doi.org/10.14214/sf.a13939
English title: Afforestation of drained peatlands.
Original keywords: valtionmetsät; Metsähallitus; ojitus; metsäopetus; metsänviljely; metsänhoitajien jatkokurssit; luontainen uudistaminen; metsitys; suot
English keywords: afforestation; natural regeneration; drained peatlands; peatlands; forest regeneration; Forest Service; forest education; state forests; professional development courses
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes afforestation of drained peatlands. 

  • Lukkala, E-mail: ol@mm.unknown (email)
article id 4529, category Article
V. T. Aaltonen. (1938). Maa ja metsän uudistuminen. Silva Fennica no. 46 article id 4529. https://doi.org/10.14214/sf.a13938
English title: Forest regeneration and soil.
Original keywords: metsäopetus; metsänhoitajien jatkokurssit; luontainen uudistaminen; kulotus; maanmuokkaus; metsämaa; maaperä
English keywords: regeneration; soil preparation; natural regeneration; soil; forest education; professional development courses; broadcast burning
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes the effect of properties of soil on forest regeneration. 

  • Aaltonen, E-mail: va@mm.unknown (email)
article id 4492, category Article
V. K. Ahola. (1937). Metsän keinollisesta uudistamisesta. Silva Fennica no. 39 article id 4492. https://doi.org/10.14214/sf.a13902
English title: Artificial regeneration of forests.
Original keywords: metsäopetus; kylvö; metsänhoitajien jatkokurssit; metsän uudistaminen; istutus
English keywords: planting; forest regeneration; forest education; sowing; professional development courses
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level.

 This presentation describes the methods of artificial regeneration of forests.

  • Ahola, E-mail: va@mm.unknown (email)
article id 4486, category Article
Martti Tertti. (1937). Metsien luontaisen uudistumisen edistämisestä. Silva Fennica no. 39 article id 4486. https://doi.org/10.14214/sf.a13896
English title: Facilitating natural regeneration.
Original keywords: metsänhoito; metsäopetus; kylvö; metsänhoitajien jatkokurssit; luontainen uudistaminen; taimetuminen
English keywords: natural regeneration; silviculture; forest education; sowing; professional development courses
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes natural regeneration in forests and factors affecting the success of regeneration.

  • Tertti, E-mail: mt@mm.unknown (email)
article id 4479, category Article
L. E. T. Borg. (1936). Hankikylvöt Tuomarniemen hoitoalueessa vv. 1913-1930. Silva Fennica no. 38 article id 4479. https://doi.org/10.14214/sf.a9065
English title: Areas broadcast sown on snow in Tuomarniemi district in Finland in 1913-1930.
Original keywords: kuusi; Picea abies; kylvö; euroopanlehtikuusi; kylvömenetelmät; hankikylvö; Larix decidua; mänty; metsänviljely; Pinus sylvestris
English keywords: Norway spruce; sowing; broadcast sowing on snow; Socts pine; artificial regeneration
Abstract | View details | Full text in PDF | Author Info

Broadcast sowing on snow was relatively new method in the beginning of the 20th century in Finland, and the experiences of regeneration were diverse. The aim of the survey was to study the success rate of regeneration in the oldest and largest areas regenerated with this sowing method in Tuomarniemi district. Scots pine (Pinus sylvestris L.) was the most common tree species, but also Norway spruce (Picea abies (L.) H. Karst.) and European larch (Larix decidua Mill.) were used in broadcast sowing on snow.

According to the study, the success of broadcast sowing on snow was as good as patch sowing and sowing in furrows in the sites typical for Tuomarniemi. The regeneration areas were often drained peatlands or paludified lands. When sowing is done using Norway spruce seeds, site preparation either by broadcast burning or scalping with hoe is recommended. Mixed sowing with pine and spruce seldom succeeded due to the differences in site requirements of the species and growth of seedlings. Sowing of Scots pine succeeded well on the drained peatlands. Sowing should be done some years after draining to let the peat dry and sink. Site preparation is needed in sites growing Polytrichum-moss. Broadcast burned areas larger than 10 hectares seemed to regenerate poorer than sites in average, possibly due to dryness of the sites. Trials with European larch were successful, and the growth of the seedlings acceptable despite the sites being relatively poor for the species.

The PDF includes a summary in German.

  • Borg, E-mail: lb@mm.unknown (email)
article id 4451, category Article
Pekka Urho Sakari Tikka. (1928). Havaintoja kuusen esiintymisestä ja kehityksestä Pohjois-Suomen kuivissa kangasmetsissä. Silva Fennica no. 10 article id 4451. https://doi.org/10.14214/sf.a8399
English title: Observations on Norway spruce growth and development in dry mineral soil sites in Northern Finland.
Original keywords: Pohjois-Suomi; luontainen uudistuminen; kuiva kangas; kuusi; Picea abies; taimi
English keywords: Norway spruce; natural regeneration; seedling; northern Finland; dry upland site
Abstract | View details | Full text in PDF | Author Info

Norway spruce (Picea abies (L.) H. Karst.) is rarely the dominant species on dry mineral soil sites in Northern Finland. These sites are, in general, too poor and dry for spruce, and suit better for Scots pine (Pinus sylvestris L.). According to the study, the natural regeneration of spruce is in Northern Finland poor. In the sample plots, cones could be found in 35% of spruce trees in the stands in natural state and 46% in the harvested stands. Compared to the spruce areas in Northern Finland, or fresh mineral soil sites in Southern Finland, cone and seed production of Norway spruce was in dry mineral soil sites very low due to scarcity of seed trees and their low cone number. There were few spruce seedlings in the sample plots, but according to the observations, spruce is able to regenerate on lichen and heath covered sites. The seedling growth was, however, poor on dry sites. Spruce seedlings were often found near fallen trees and stumps. The growing trees prevent growth of seedlings of all species. Norway spruce seems, however, to be able to spread also to the poor sites. The success depends on the vegetation and dryness of the site. For instance, spruce can spread to dry mineral soil sites from seed trees of nearby peatlands.

The PDF includes a summary in German.

  • Tikka, E-mail: pt@mm.unknown (email)

Category : Article

article id 7181, category Article
Eino Oinonen. (1967). Keltalieon (Lycopodium complanatum L.) itiöllinen uudistuminen Etelä-Suomessa kloonien laajuutta ja ikää koskevan tutkimuksen valossa. Acta Forestalia Fennica vol. 83 no. 3 article id 7181. https://doi.org/10.14214/aff.7181
English title: Sporal regeneration of ground pine (Lycopodium complanatum L.) in Southern Finland in the light of the dimensions and the age of its clones.
Keywords: regeneration; forest fire; Pteridium aquilinum; bracken fern; ground pine; Lycopodium complanatum; Diphasiastrum complanatum; sporal regeneration
Abstract | View details | Full text in PDF | Author Info

In an earlier paper of the author it was established that sporal regeneration of bracken fern (Pteridium aquilinum (L.) Kuhn.) is almost entirely connected with fire, and that the size of the bracken fern clones, distinguished by their characteristics, was related to the time of the fire. In previous studies has been found that also sporal regeneration of ground pine (Lycopodium complanatum L., now Diphasiastrum complanatum) is rare. The occurrence of several plant species were studied in relation to bracken fern in the earlier investigation. This paper reports findings concerning ground pine.

When the size-age problem of bracken fern was solved, parallel measurements of ground pine stand on the same site led to the solution of the size-age problem and sporal regeneration of ground pine. The linkage is also valid when the size of ground pine stands was compared to the dates of fires. The ground pine stands are very long-lasting. The stands are fragmented more easily than bracken fern by environmental factors, such as fires, and tend to form large patch clusters with time. Large individual stands reveal the rarity of sporal regeneration of ground pine. The resemblance with bracken fern clones indicate a common factor of regeneration, fire, and a very even spreading rate. Though considerable variation of the colour and structure of ground pine was observed, the circular stands were identical patch by patch.

The PDF includes a summary in English.

  • Oinonen, E-mail: eo@mm.unknown (email)
article id 7180, category Article
Eino Oinonen. (1967). The correlation between the size of Finnish bracken (Pteridium aquilinum (L.) Kuhn.) clones and certain periods of site history. Acta Forestalia Fennica vol. 83 no. 2 article id 7180. https://doi.org/10.14214/aff.7180
Keywords: regeneration; distribution; forest fire; Pteridium aquilinum; bracken fern; wars; ground fire
Abstract | View details | Full text in PDF | Author Info

In an earlier paper of the author it was established that bracken fern (Pteridium aquilinum (L.) Kuhn.) that the sporal regeneration of the species is almost entirely connected with fire, and that the size of the bracken fern clones, distinguished by their characteristics, was related to the time of the fire. The time of the fire was determined by the samples taken with auger from the trees on the sample plots. A large data on the occurrence of bracken fern was collected around Finland, but only part of it could be used in the previous study, as the trees of the site provided no means to find out it the site had been burned earlier.

In earlier studies, a mass occurrence of sporelings of bracken fern in England has been connected to cities bombed and burned during the World War II. In this study the data of the clones is connected to historical sources and the time of wars in Finland. The comparisons in this study have confirmed the results achieved by comparing the dimensions of the bracken clones to the fire dates. It was found that the wars have caused an increase in the regeneration frequency of bracken fern.

  • Oinonen, E-mail: eo@mm.unknown (email)
article id 7179, category Article
Eino Oinonen. (1967). Sporal regeneration of bracken (Pteridium aquilinum (L.) Kuhn.) in Finland in the light of the dimensions and the age of its clones. Acta Forestalia Fennica vol. 83 no. 1 article id 7179. https://doi.org/10.14214/aff.7179
Keywords: regeneration; distribution; Pteridium aquilinum; bracken fern
Abstract | View details | Full text in PDF | Author Info

The objective of the present study was to obtain information on the regeneration by spores of bracken fern (Pteridium aquilinum (L.) Kuhn.) as well as the permanence and vegetative spreading of the clones. Prevention of bracken fern, which can hinder forest regeneration, is possible only when the basic facts of the life cycle is known. It would be useful to know if it is probable that bracken fern can become prevalent by spore regeneration, and to what extent it invades forest land by vegetative spreading.

No bracken fern sporelings were found, and the experiments of regeneration by spores were unsuccessful, therefore, the studies were concentrated on the clones. Due to the fire tolerance of the plant, it was expected that the clone material would show gradation according to the periods of fire. The first part of the work concerns individual variation in bracken, the second part concentrates on the data collected from sample plots, which latest fire could be dated from the trees.

The results of the studied clones confirm the correlation between the stands interpreted as clones and the length of the post-fire period. The stands were delimited to clones by their individual characteristics. The spreading on average sites (Vaccinium and Myrtillus type forests) was in average 35.8±2 cm annually. It is concluded that bracken fern regeneration by spores is very rare in Finland and that it has been rarer during the last 50 years compared to the preceding period. This is probably caused by the end of slash-and-burn cultivation and decrease of forest fires in Finland. Bracken fern clones often survive the fires through their rhizomes, and fragments of old clones originating before the fire could be found in the study areas. These clones may be even 300 years old. Especially in its northern areas of distribution, bracken fern is connected with settlement and old slash and burn sites. Regeneration by spores in the northern distribution areas seem to be less than in the southern areas.

  • Oinonen, E-mail: eo@mm.unknown (email)
article id 7178, category Article
Matti Keltikangas, Pekka Tiililä. (1968). Koivun ja kuusen istutuksen keskinäinen edullisuusjärjestys käenkaali-mustikkatyypin metsämailla. Acta Forestalia Fennica vol. 82 no. 5 article id 7178. https://doi.org/10.14214/aff.7178
English title: The economic sequence of silver birch (Betula pendula) and Norway spruce (Picea abies) when planting Oxalis-Myrtillus type forest land.
Original keywords: kuusi; kannattavuus; koivu; istutusmetsikkö; puulajivalinta; tuottotaulukot
English keywords: Norway spruce; Betula pendula; Picea abies; silver birch; planting; profitability; artificial regeneration; yield tables; choise of tree species
Abstract | View details | Full text in PDF | Author Info

The present study proposes to calculate the economic sequence of two of Finland’s three main tree species, Norway spruce (Picea abies (L.) H. Karst.) and silver birch (Betula pendula Roth) when planted on Oxalias-Myrtillus type sites where both species are equally suitable, on biological grounds. In addition, the accuracy and applicability of the present Finnish yield tables to an economic comparison is tested. Benefit/cost ratio was selected as criterion of profitableness. All future net incomes and costs were discounted into the planting time and added together. The ratio between the discounted net revenues and the discounted investment costs (later called profit ratio) was the criterion. There is no reliable method to forecast the future wood prices, therefore two price ratios, birch veneer timber to spruce pulpwood and birch cordwood to spruce pulpwood, were chosen as free variables. The economic sequence of the tree species was determined as the function of these variables.

The main conclusions are, first, that under the present price ratios spruce appears to be the better choice for the forest owner, and the most promising policy for changing the situation seems to decrease the production costs of plants in birch nurseries. Second, the present Finnish yield tables are not consistent or accurate enough to enable any sufficiently reliable economic comparisons of tree species in artificial regeneration. The possible error of difference between two rather uncertain estimates is big. More work is needed to construct a uniform system of yield tables covering all main tree species, all site types, all macro climate conditions and all types of regeneration.

The PDF includes a summary in English.

  • Keltikangas, E-mail: mk@mm.unknown (email)
  • Tiililä, E-mail: pt@mm.unknown
article id 7135, category Article
Paavo Yli-Vakkuri. (1961). Kokeellisia tutkimuksia taimien syntymisestä ja ensi kehityksestä kuusikoissa ja männiköissä. Acta Forestalia Fennica vol. 75 no. 1 article id 7135. https://doi.org/10.14214/aff.7135
English title: Experimental studies on the emergence and development of tree seedlings in spruce and pine stands.
Original keywords: kuusi; kylvö; mänty; taimettuminen; uudistuminen; uudistaminen; itäminen
English keywords: Pinus sylvestris; Norway spruce; Picea abies; germination; regeneration; Scots pine; seedlings; sowing; seeding; restocking with seedlings
Abstract | View details | Full text in PDF | Author Info

This paper aims at studying regeneration of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) by sowing and natural regeneration of birch (Betula sp.) in Western Finland.

Germination of spruce and pine seeds may be prevented by dryness and temperatures below the optimum for germination. In natural conditions, when temperature and moisture is insufficient for germination, the type of seedbed generally has en effect on germination result. Trenching of the seeding spots showed that root competition during the early stage of regeneration was not of decissive importance. It seemed to, however, improve the preservation of the seedlings later. It is common that it can take long before the seeds germinate, and during that time the number of viable seeds decrease strongly.

Also, the seedling stock quickly began to decrease in number after germination, especially during the first growing season and the following winter. The decrease was larger in intact vegetation than on mineral soil or in the humus layer. The emerging seedlings were destroyed by drought very easily, but their tolerance to drought improved later on.

The PDF includes a summary in English.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
article id 7130, category Article
Paavo Yli-Vakkuri. (1961). Tutkimuksia männyn kylvöalojen metsittymisvaiheesta. Acta Forestalia Fennica vol. 74 no. 3 article id 7130. https://doi.org/10.14214/aff.7130
English title: Studies on the development of young sown pine stands in Central Finland.
Original keywords: kylvö; mänty; taimikko; uudistaminen
English keywords: Pinus sylvestris; regeneration; Scots pine; seedling stand; sowing; seeding
Abstract | View details | Full text in PDF | Author Info

In this paper the development of sown Scots pine (Pinus sylvestris L.) seedling stands into forests is studied. The material was collected in stands sown in 1930–1940 in private forests in the Forestry Board districts of Central and Northern Ostrobothnia. The 119 areas, including both burned and other areas, were studied in 1955.

Most seedings had been carried out on relatively poor soils, mostly representing Vaccinium and Calluna type forests. 71% of the areas consisted of large forest fires, mostly from 1933. The most burned areas did not have seed producing trees nearby. The other sown areas were in general small, 1–2 ha, and near forests capable of producing seeds. The species of previous tree generation, in the older areas mostly pine and in the younger areas Norway spruce, affected tree species composition of the new tree generation.

Over 90% of the burned areas were in silviculturally good or satisfactory condition, while the main part of the other sown stands was in fair or poor condition. Weeding and thinning had been done only in the oldest stands. Most stands had been left untended. Natural new trees often competed with the sown pines, and cull-trees and border forest increased natural regeneration in the areas. In Calluna type the poor soil limited regeneration and growth of broadleaf trees. The worst competitors were naturally regenerated pine seedlings both on Calluna and Vaccinium type. On Vaccinium type also birch and sometimes also aspen (Populus tremula L.) competed with sown pine. On better sites and paludified areas competition by broadleaf trees increased. The rhythm of development of broadleaved trees is so different from pine that only those broadleaved trees that are formed in the stand when the pine seedlings are larger can develop harmoniously with pine. Due to the harmful competition, the seedling stands should be tended early on. In addition, it may be advisable to abandon the practise to leave trees on sowing areas.

The PDF includes a summary in Finnish.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
article id 7129, category Article
Erkki K. Kalela. (1961). Natural regeneration of agricultural lands in so-called Porkkala-area of leased land. Acta Forestalia Fennica vol. 74 no. 2 article id 7129. https://doi.org/10.14214/aff.7129
Keywords: natural regeneration; agricultural land; dominant species
Abstract | View details | Full text in PDF | Author Info

The size of the field and the ditching on it as well as the condition of the field at the time of the surrender of Porkkala area (from Finland to Russia) play an important role on how far the natural regeneration of the fields has progressed.

Larger open fields have naturally regenerated only on sides where the surrounding forest can spread the seeds or the thicket of saplings has reached, whereas small parcels of fields have normally been fully forested. Most important species have been e.g. silver birch and pubescent birch, grey and common alders and European aspen as well as pine and spruce. The broad leaved species are dominant.     

The PDF contains a summary in Finnish.

 

  • Kalela, E-mail: ek@mm.unknown (email)
article id 7128, category Article
Paavo Yli-Vakkuri. (1961). Emergence and initial development of tree seedlings on burnt-over forest land. Acta Forestalia Fennica vol. 74 no. 1 article id 7128. https://doi.org/10.14214/aff.7128
Keywords: Pinus sylvestris; Norway spruce; Picea abies; germination; regeneration; Scots pine; seeds; prescribed burning; sowing; seeding
Abstract | View details | Full text in PDF | Author Info

Prescribed burning has been used in regeneration areas in Finland as a method to treat the humus layer and creating more favourable chemical, physical and biological conditions for the seedlings. At the same time, fire clears away seedlings and shoots of unwanted trees and other vegetation. Direct sowing or planting, mostly Scots pine (Pinus sylvestris L.), seldom natural regeneration, is used. In this paper, the initial stages of the formation of a new tree generation of Scots pine and Norway spruce (Picea abies (L.) Karst.) on prescribed burned areas is studied in Central Finland in 1956–1960.

The burned area remains almost without vegetation for about two growing seasons. Conditions on a burned area which has not been tiled are very unfavourable for germination of seeds of coniferous and deciduous trees. On the other hand, shoots of deciduous trees occur soon after burning. Conditions for regeneration were found to be better 3–5 years after burning. Removal of humus layer in spots improved regeneration. However, the patches facilitated also natural regeneration of Norway spruce and especially birch (Betula sp.), which compete with Scots pine seedlings.

Continuous rainy periods improved the germination of Scots pine and Norway spruce seeds sown on the humus layer. Pine and spruce developed more rapidly on the exposed soil, however, young seedlings were easily destroyed. Seed eaters destroyed the pine and spruce seeds sown on the humus layer of newly burned areas completely or almost completely. The viability of pine seeds sown on the burned humus layer did not decrease for three weeks, but the viability greatly weakened after six or more weeks. Spruce seeds lost their viability faster than pine seeds.

The PDF includes a summary in Finnish.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
article id 7478, category Article
Paavo Yli-Vakkuri. (1958). Tutkimuksia ojitettujen turvemaiden kulotuksesta. Acta Forestalia Fennica vol. 67 no. 4 article id 7478. https://doi.org/10.14214/aff.7478
English title: Studies on prescribed burning of drained peatlands.
Original keywords: mänty; luontainen uudistaminen; kulotus; suot; pintakasvillisuus; turvemaat; uudistaminen; turvekankaat; vesaikko
English keywords: Pinus sylvestris; regeneration; natural regeneration; drained peatlands; Scots pine; coppice; peatlands; ground vegetation; prescribed burning
Abstract | View details | Full text in PDF | Author Info

Prescribed burning has been used to treat the mineral soil sites, but the method has been little used in drained peatlands. The course and methods of prescribed burning in drained peatlands, and the effect of burning on sprouting of broadleaved trees, growth of ground vegetation and regeneration of Scots pine (Pinus sylvestris L.) by sowing was studied in drained pine bogs in Southern Finland. The top layer of the peat was mostly Sphagnum peat. The material included a prescribed burned 12 ha drained peatland area in Tuomarniemi district, in addition to which ten previously burned areas were investigated.

The burning had succeeded mostly well, but also unsuccessfully burned sites were observed. Estinguishing of the fire was easy, and no peat fires occurred. The fire burned only the logging residue, ground vegetation and the dry top layer of the peat. The roots of brushwood and grasses survived in the peat that insulated the top layer from the heat. For instance, the abundance of cloudberry (Rubus chamaemorus L.) increased after the fire. Similarly, burning did not affect sprouting of the stumps of downy birch (Betula pubescens Ehrh.). It cannot thus be used as a method to restrict the growth of coppice in regenerated areas. The seeds of Scots pine germinated well on the burned surface. 46% of the seeds developed to seedlings on sphagnum-shrub vegetation and 16% in feathermoss-shrub vegetation.

The PDF includes a summary in German.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
article id 7472, category Article
Jaakko Lehto. (1956). Tutkimuksia männyn luontaisesta uudistumisesta Etelä-Suomen kangasmailla. Acta Forestalia Fennica vol. 66 no. 2 article id 7472. https://doi.org/10.14214/aff.7472
English title: Studies on the natural regeneration of Scots pine on the upland soils of Southern Finland.
Original keywords: mänty; luontainen uudistaminen; taimettuminen; uudistuminen
English keywords: Pinus sylvestris; regeneration; natural regeneration; Scots pine; stocking with seedlings
Abstract | View details | Full text in PDF | Author Info

Natural regeneration of Scots pine (Pinus sylvestris L.) by leaving a seed tree stand on a cutting area has long been the most popular regeneration method in Finland. Results of the method have, however, been unsatisfactory. The aim of the investigation was to study the basic problems of natural regeneration of Scots pine. Regeneration success was studied in 144 sample plots in pine stands at different stages of regeneration in Southern Finland. In addition, the data included information of 42 previously investigated areas.

According to the results, Scots pine can be successfully regenerated naturally on sandy and gravelly soils in Southern Finland. Preparing the ground surface by breaking or burning considerably facilitates the establishment of a seedling stand. The number of seedlings was considerably lower in the ground vegetation than in the mineral soil. Considering growth of the seedlings, root competition of the mother trees was heavy in dense stands, but insignificant in thin stands. The stand density did not affect germination of the seeds. In regeneration areas proper, where the density of mother trees usually is under 50 per hectare, there was in average 4,700 seedlings per hectare in Calluna type forests and 5,200 in Vaccinium type forests.

The PDF includes a summary in English.

  • Lehto, E-mail: jl@mm.unknown (email)
article id 7453, category Article
Gustaf Sirén. (1955). The development of spruce forest on raw humus sites in Northern Finland and its ecology. Acta Forestalia Fennica vol. 62 no. 4 article id 7453. https://doi.org/10.14214/aff.7453
Keywords: Norway spruce; regeneration; succession; northern Finland
Abstract | View details | Full text in PDF | Author Info

According to the National Forest Inventory of Finland, the age structure of forests in Northern Finland require large-scale fellings. One of the problems is regeneration of low-productive Norway spruce (Picea abies (L.) Karst.) forests in the area. The objectives of this investigation were to study the natural development of Hylocomnium-Myrtillus (HMT) type Norway spruce forests in Northern Finland and the ecological causes of the development. A total of 83 sample plots were studied in 1950-52. The stands were chosen to have a total effective temperature during growing season between 600-800 ºC.

According to the results, the HMT type forests represent secondary developmental stages of the northern Myrtillus type, characterized by tree stands of poor quality. By returning the habitats that have reached their secondary stages to their primary stage, e.g. by means of fires, the potential site quality is restored. The climax theory is inapplicable to the Northern Finland’s spruce stands on fresh site types. The natural development of HMT follows not the climax theory, i.e. a return in each succession to the same type stage expressing the same site quality. One reason is accumulation of the thick humus layer, caused by incomplete decomposition of litter. The humus binds nutrients inaccessible to the trees, and the substratum becomes cold, more acid, and moist.

These forests should be managed by clear-cutting, burning-over and artificial regeneration. When thinning the stands, at least a slight mixture of deciduous trees must be left in the stand.

The article is divided into two separate PDFs. The second PDF is in a supplementary file and includes a summary in Finnish.

  • Sirén, E-mail: gs@mm.unknown (email)
article id 7440, category Article
Erkki K. Kalela. (1954). Mäntysiemenpuiden ja -puustojen juurisuhteista. Acta Forestalia Fennica vol. 61 no. 28 article id 7440. https://doi.org/10.14214/aff.7440
English title: Root systems of Scots pine seed trees and stands.
Original keywords: mänty; taimettuminen; juuristo; uudistuminen; siemenpuut; juurikilpailu
English keywords: Pinus sylvestris; regeneration; natural regeneration; Scots pine; seedlings; seed trees; root system; root competition
Abstract | View details | Full text in PDF | Author Info

Root systems of a Scots pine (Pinus sylvestris L.) stands of seed trees on a Vaccinium sites in Southern Finland were studied by taking soil samples around the seed trees. The results show that root system of an old Scots pine spreads relatively evenly around the tree up to at least 10 meters from the stem. The densest part of the root system is near the stem, which part is often acentric. This is probably due to root competition in the early stages of growth of the tree.

Root systems of the seed trees affect stocking of the site with seedlings and the growth of the seedlings. The root competition can cause, for instance, uneven grouping of the seedlings. It seems that the largest trees of a stand have the most even root system. It is therefore recommended to choose the strongest trees of the stand as seed trees, to ensure even distribution of seedlings.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in German.

  • Kalela, E-mail: ek@mm.unknown (email)
article id 7439, category Article
Leo Heikurainen. (1954). Rämemänniköiden uudistamisesta paljaaksihakkausta käyttäen. Acta Forestalia Fennica vol. 61 no. 27 article id 7439. https://doi.org/10.14214/aff.7439
English title: Regeneration of Scots pine stands of pine swamps through clear cutting.
Original keywords: männikkö; luontainen uudistuminen; mänty; suot; alikasvos; uudistaminen; räme; turvekangas; avohakkuu
English keywords: Pinus sylvestris; regeneration; natural regeneration; drained peatlands; Scots pine; peatlands; seedlings; fellings; undergrowth; pine swamps; clear cutting
Abstract | View details | Full text in PDF | Author Info

Pine swamps are easily regenerated by natural regeneration of Scots pine (Pinus sylvestris L.). Usually seeding felling is used, but also strip system or clear cutting and regeneration along stand edge has been suggested. This article discusses the regeneration by clear cutting and sparing the existing undergrowth. The article focuses on pine swamps to be drained and the ones in natural state.

Pine swamps in natural state usually have plenty of trees of smaller diameter classes, that can be trusted to form the future tree generation after the felling. This shortens the rotation by 20-30 years. The undergrowth has been shown to recover quickly. The method suits for regeneration of drained peatlands but could fit also for regeneration of pine swamps in natural state.

The seedlings in the pine swamps are mainly 1-5 years old, and the stock is changing. It seems that larger trees produce a wider selection of age groups, but the seedlings survive longer under smaller mother trees. Part of the younger generations of seedlings seem to be destroyed when the peatland is drained. Further studies are needed to investigate how the draining and felling are to be performed to spare the young seedlings.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in German.

  • Heikurainen, E-mail: lh@mm.unknown (email)
article id 7402, category Article
Gustaf Sirén. (1950). Alikasvoskuusten biologiaa. Acta Forestalia Fennica vol. 58 no. 2 article id 7402. https://doi.org/10.14214/aff.7402
English title: On the biology of undergrown Norway spruce.
Original keywords: kuusi; alikasvos; juuristo; uudistuminen; iänmääritys; latvus; toipumiskyky
English keywords: Norway spruce; Picea abies; regeneration; natural regeneration; age; crown; undergrowth; root system
Abstract | View details | Full text in PDF | Author Info

Norway spruce (Picea abies (L.) Karst.) invading sites is common in Finland. The species tends to establish itself as undergrowth, and takes over when it gets space to grow. To determine whether the undergrowth is suitable as the new generation requires knowledge on the biology of spruce undergrowth. One of the issues is determining the age of the stunted trees. In this investigation, 100 undergrown spruce trees, their crown and their root systems were studied. A method was developed to determine the age of the trees.

The root system of all trees in Vaccinium sites and of stunted trees in Myrtillius sites were superficial. The root systems of older spruces were purely of adventitious origin. The longer the period of stunting growth, the younger is the root system. In addition to acropetal and general adventitious ramification there is often adventitious branching of the roots of pathological causes. Mortality among the long roots is frequent.

A stunted tree has not the same ability as a viable tree to make use of already existing branches for building assimilating surface. When comparing trees with equally large assimilating surface, a stunted tree had greater sum of roots compared to a viable tree. The root system of a stunted undergrown spruce was very superficial compared with the other trees.

The PDF includes a summary in English.

  • Sirén, E-mail: gs@mm.unknown (email)
article id 7377, category Article
S. E. Multamäki. (1942). Kuusen taimien paleltuminen ja sen vaikutus ojitettujen soiden metsittymiseen. Acta Forestalia Fennica vol. 51 no. 1 article id 7377. https://doi.org/10.14214/aff.7377
English title: Frost injuries of Norway spruce seedlings and their effect on afforestation of drained peatlands .
Original keywords: kuusi; ojitus; uudistuminen; kylmänkestävyys; turvekangas; pakkasvaurio; keväthalla; ojitettu suo; suojametsä
English keywords: Norway spruce; Picea abies; regeneration; drained peatlands; frost damage; peatlands; frost resistance; spring frost; prorective forest
Abstract | View details | Full text in PDF | Author Info

The aim of the investigation was to study natural regeneration of Norway spruce (Picea abies (L.) Karst.) in drained peatlands and frost injuries in seedlings, and to compare microclimates of the regeneration areas. The experiments included peatlands in Satakunta in Western Finland. Restocking of the areas with seedlings and their survival was followed in 1935-40 at sample plots that were mainly 1 are large.

Susceptibility to freezing was shown to be dependent on the stage of development of the shoots. Shoots that have just begun to grow contain little water, and withstand better freezing temperatures than shoots in later stages of growth. Damages to the seedlings were observed when the temperatures decreased to -2.8–-4.3 °C. The most severe damage to a seedling was caused by the death of the leading shoot by spring frost.

Norway spruce regenerates easily on moist peatlands, but peatlands with dry surface tend to have little or no seedlings. The species regenerated better in marshy sites than correspondingly fertile mineral soil sites. However, it needs shelter to avoid frost damage. On clear cut spruce swamp the undergrowth spruce seedlings that were left in the site got severe frost damage. If the site had birch (Betula sp.) coppice or undergrowth, spruce seedlings survived in their shelter depending on the height and density of the birch trees. To be effective, the protective forest should have relatively even crown cover. Young spruce seedlings could grow well even under relatively dense birch stand.

The PDF includes a summary in German.

  • Multamäki, E-mail: sm@mm.unknown (email)
article id 7356, category Article
Peitsa Mikola. (1942). Koivun vesomisesta ja sen metsänhoidollisesta merkityksestä. Acta Forestalia Fennica vol. 50 no. 3 article id 7356. https://doi.org/10.14214/aff.7356
English title: Silvicultural usefulness of sprouting of birch.
Original keywords: Etelä-Suomi; Pohjois-Suomi; koivu; uudistuminen; rauduskoivu; hieskoivu; vesominen; vesatalous; juurivesa
English keywords: birch; Betula pendula; coppicing; regeneration; silver birch; sprouting; downy birch; decay; Betula verrucosa
Abstract | View details | Full text in PDF | Author Info

Birches’ (Betula sp.) ability to grow sprouts is low. The stump grows root collar and stump shoots, but the stump shoots are not proper stump shoots that will grow from the space between wood and bark. The buds are situated very low in the base, even under the ground. In this study, no actual root shoots could be found. Also the bushy alpine birches seem to be formed from stump and root collar shoots.

In Southern Finland silver birch (Betula pendula Roth) is more common than downy birch (Betula pubescens Ehrh.) in dry upland forest sites, while downy birch is common in fresh mineral soil forests and peatlands. In Northern Finland downy birch is the dominant birch species. Of the two species downy birch has markedly better capacity to form stump and root collar shoots both in Northern and Southern Finland. In general, birches grow sprouts much more strongly in Northern Finland.

Growth of the shoots is fastest during the first year after the felling of the parent tree and slows down gradually. The stump shoots may get separated from the stump when the stump decays, and the decay may also spread to the shoots. It is common that the shoots have no own roots, and die along with the stump. The shoots may have own root system or use roots of the parent tree that have stayed alive, in the latter case decay spreads almost always from the stump to the shoot. Whether the tree was felled with axe or saw had no effect on sprouting, probably because the sprouting buds are situated in the base of the tree. The larger stumps had usually fewer sprouts than smaller stumps. The fertility of the site seemed to have little effect on sprouting, but more moist sites formed more sprouts.

Forest regeneration using sprouts may be possible in peatlands for firewood production. on mineral soil sites birch does not suit for coppicing. The proportion of trees originating from sprouts decreases strongly by the time. Consequently, in Southern Finland sprouts have little effect on regeneration of birch. In Northern Finland sprouting is the most important way of regeneration.

The PDF includes a summary in German.

  • Mikola, E-mail: pm@mm.unknown (email)
article id 7351, category Article
Esko Kangas. (1940). Tuloksia Pohjankankaan ja Hämeenkankaan metsänviljelyksistä. Acta Forestalia Fennica vol. 49 no. 4 article id 7351. https://doi.org/10.14214/aff.7351
English title: Studies on artificial regeneration in Pohjankangas and Hämeenkangas in Southern Finland.
Original keywords: kylvö; mänty; metsäpalo; metsänuudistaminen; taimikko; kulo; hyönteistuho; sienituho
English keywords: Pinus sylvestris; regeneration; Scots pine; seedling damage; ; seedling stands; insect damage
Abstract | View details | Full text in PDF | Author Info

The regeneration of forests in Hämeenkangas area in Southern Finland has been difficult due to various damages from the middle of the 1800s. Few seed trees were left in the area, and artificial regeneration has been used since 1880s. The area became an experimental area of the Forest Research Institute in 1924. The aim of the study was to survey the area before it was transferred to the Finnish Defense Forces.

The original Scots pine (Pinus sylvestris L.) forest of the esker area suffered from many forest fires. The total area is 13,000-14,000 ha, of which the experimental forests of Forest Research Institute cover 6,000 ha. The area is dry upland forest, and drought affects the survival of germlings. Soil frost is a major cause of loss of young seedlings. Sowing method affects the early development of the seedlings. Band sowing proved to be the best method regarding the soil frost. A total of 39 different harmful insect species, 8 pathogen species and 7 other causes of damages have been detected in the area.

The development of seedling stands follow a certain pattern, reported also in other studies. Many of the pine seedling stands develop well until they reach a certain height. After that seedlings begin to suffer from damages, but after reaching another stage develop normally. The damages affect the height growth of the seedlings. Some common damages are caused by Pissoides weevils, needle damages caused by certain beetles, shoot damages by Evetria resinella, and pine blister rust (Peridermium pini and Cronartium flaccidum).

The PDF includes a summary in German
  • Kangas, E-mail: ek@mm.unknown (email)
article id 7350, category Article
Ilmari Paasio. (1941). Plant sociological principles of open bog types. Acta Forestalia Fennica vol. 49 no. 3 article id 7350. https://doi.org/10.14214/aff.7350
Keywords: population; classification; treeless bog; open bog; plant sociology; plant stand; phytogenesis
Abstract | View details | Full text in PDF | Author Info

The plant populations of Finnish open bogs are typically formed of two layers. The layers normally consist of one or rarely two species. The structure of plant populations in open bogs is a consequence of the development where determining factors are different site requirements of the species, and the differences in the biotic vitality and capacity for reproduction.

Phytogenesis should be taken as a basic unit for describing the plant societies or vegetation of treeless bogs. However, acknowledging the sub-populations may be of advantage for describing the ecological, genetic and regional characters of open bogs.

The basic classification of open bogs must be done based on the ground layer. The more detailed classification follows mostly based on field layer, partly also based on the ground layer.

The PDF contains a summary in Finnish. 

  • Paasio, E-mail: ip@mm.unknown (email)
article id 7300, category Article
Olli Heikinheimo. (1934). Metsänviljelysmenetelmiä koskevista tutkimuksista. Acta Forestalia Fennica vol. 40 no. 23 article id 7300. https://doi.org/10.14214/aff.7300
English title: Research on forest regeneration methods.
Original keywords: metsäntutkimus; metsänviljely; metsän uudistaminen; viljelykoe
English keywords: articifial regeneration; forest researc
Abstract | View details | Full text in PDF | Author Info

The article is a review on the research about forest regeneration in Finland, executed in the Forest Research Institute. The climate affects the results of different regeneration methods. Thus, sample plots have been established in different parts of the country. In 1933 there was a total of 386 sample plots around the country. To compare the effect of weather conditions in the regeneration, sample plots have been established in successive years. Other conditions that affect forest regeneration are soil, forest site type, tree species, time from the felling of the stand, and tending of the seedling stand. Of the 386 sample plots 245 were planting experiments and 141 sowing experiments.

The PDF includes a summary in German.

  • Heikinheimo, E-mail: oh@mm.unknown (email)
article id 7294, category Article
Martti Hertz. (1934). Tutkimuksia karjan vaikutuksesta hakkausalojen kasvillisuuteen. Acta Forestalia Fennica vol. 40 no. 17 article id 7294. https://doi.org/10.14214/aff.7294
English title: Studies on influence of grazing on the vegetation of cutting areas.
Original keywords: luontainen uudistuminen; kuusi; karja; laidunnus; mesälaidun; hakkuualue
English keywords: Picea abies; natural regeneration; spruce; cattle; forest pasture
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to determine the effect of grazing of the cutting areas to the ground vegetation and regeneration of spruce. The cutting areas could be divided into two kinds of areas based on the vegetation. Hillocks were drier and poorer than other parts of the cutting areas. Their vegetation did suffer less from grazing than the other parts of the cutting areas. The shade-loving plant species decreased, but as the poorer sites have less edible plants, cattle caused less damage than in the better sites. The even spaces between the hillocks had both positive and negative changes. Cattle transport seeds, tile and fertilize the soil, promote paludification, and decrease competition by the primary species like large grasses. This is beneficial to new species. Grazing is directed to large grass species like Calamagrostis. Those species that cattle reject, become more abundant. Stamping damages especially shallow rooted species and perennial species, like Norway spruce (Picea abies (L.) H. Karst.). Larger tree seedlings may get injuries in the stem.

The PDF includes a summary in German.

  • Hertz, E-mail: mh@mm.unknown (email)
article id 7256, category Article
V. Pöntynen. (1929). Tutkimuksia kuusen esiintymisestä alikasvoksina Raja-Karjalan valtionmailla. Acta Forestalia Fennica vol. 35 no. 1 article id 7256. https://doi.org/10.14214/aff.7256
English title: Studies on Norway spruce undergrowth in state forests in Karelia.
Original keywords: kuusi; Picea abies; valtion metsät; metsätyyppi; alikasvos; Karjala
English keywords: natural regeneration; forest site type
Abstract | View details | Full text in PDF | Author Info

The abundance of Norway spruce (Picae abies (L.) H. Karst.) undergrowth is common for the state forests in Karelia near the Russian border, in Finland. In the survey, the occurrence of the undergrowth was studied. The article includes a review on the ownership of the forest, forest soils in the area, and the state of forests in the area. Scots pine (Pinus sylvestris L.) is the dominative species in 67%, Norway spruce in 27% and Betula sp. 6% of the state forests. Only 2% of the forests are 1‒20 years of age. Stands in the age group of 61‒80 years are the most common (25%). Norway spruce undergrowth is most abundant in the municipality of Salmi. The forests are typically moist forest site types or grass-herb site types. If the stands are allowed to develop naturally, even the Vaccinium sites become Norway spruce dominated. Spruce undergrowth is formed seldom under a spruce forest unless the stand is thin or has openings. Because Norway spruce is often rare in the mineral soil sites, the undergrowth is often regenerated from seeds that spread from spruce swamps. Earlier practiced shifting cultivation and its frequent fires prevented regeneration of spruce undergrowth. Similarly, the common felling method used, clear felling in strips, does not promote spruce undergrowth. Consequently, their occurrence is likely to decrease in the future.

The PDF includes a summary in German.

  • Pöntynen, E-mail: vp@mm.unknown (email)
article id 7232, category Article
Edvard Wibeck. (1929). Discussions on the choice of cultivation method in coniferous forests in Sweden. Acta Forestalia Fennica vol. 34 no. 19 article id 7232. https://doi.org/10.14214/aff.7232
Keywords: regeneration; afforestation; cultivation; Sweden; forest type
Abstract | View details | Full text in PDF | Author Info

In Sweden lot of state owned forests or earlier mining districts or districts of ironworks have been afforested during the last decade. The amount of afforested areas sinks from south to north. Afforestation has taken place also in privately owned forests.

The article discusses the common economic questions related to afforestation work and the biological viewpoints related to it. The best cultivation methods are presented for several common forest types, such as herb-rich forest types, moss-grown forests types, swampy forests with heavy raw humus and barren pine forest sites (lichen type).

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

  • Wibeck, E-mail: ew@mm.unknown (email)
article id 7228, category Article
Agnar Barth. (1929). Skjermforyngelsen i produksjonsökonomisk belysning. Acta Forestalia Fennica vol. 34 no. 15 article id 7228. https://doi.org/10.14214/aff.7228
English title: Natural regeneration from the production economic point of view.
Keywords: yield; natural regeneration; Norway; volume growth; seed tree stands; economic result
Abstract | View details | Full text in PDF | Author Info

Natural regeneration has been studied so far mostly on the perspective of regeneration, while the production capacity of the seed crop stand has been of little interest in the earlier studies. This paper studied volume growth of the seed trees and the economic impact of this regeneration method both in a literature review and measuring sample stands consisting of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) dominated stands and mixed forests in Norway.

It is concluded that in the most cases the seed tree stands give better pulpwood and timber yield than the stands in the average. The reason might be that the elite stems can better use their production capacity, and, thus, reach bigger and more valuable dimensions. Even though the growing stock diminishes in the seeding felling, the growth of the stand does not decrease or decreases only little. At the same time, the quality growth improves. In addition, the new tree regeneration is achieved usually without extra costs, and there is no unproductive time period in the stand.

  • Barth, E-mail: ab@mm.unknown (email)
article id 7227, category Article
D. Fehér. (1929). Biology of forest soil and its physiological meaning in the life of forest. Acta Forestalia Fennica vol. 34 no. 14 article id 7227. https://doi.org/10.14214/aff.7227
Keywords: forest management; regeneration; forest soil; soil physiology
Abstract | View details | Full text in PDF | Author Info

The article presents three studies about different aspects of the bio-chemical functions of forest soil. The three studies are i) research on microflora and microfauna of forest soils; ii) study on carbon nutrition of forests in relation to microbial functions of soil and effecting site factors and iii) study on nitrogen metabolism of forest soil. The results of the studies are summarized by every study.

The article discusses the meaning of the results for forest management in practice. The good biological and physiological condition of forest soil is important for the forest growth and it needs to be taken care in regeneration and other forest management. The natural regeneration seems to be better for soil functions. Favoring broadleaved trees as undergrowth enhances the biological processes of forest soil.   

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

  • Fehér, E-mail: df@mm.unknown (email)
article id 7195, category Article
Martti Hertz. (1925). Niinipuun uudistumisesta Suomessa. Acta Forestalia Fennica vol. 29 no. 5 article id 7195. https://doi.org/10.14214/aff.7195
English title: Regeneration of small leaved lime in Finland.
Original keywords: luontainen uudistuminen; siementuotanto; levinneisyys; lehmus; pohjoisraja; niinipuu; Tilia cordata
English keywords: regeneration; natural regeneration; distribution; seed production; northern limit
Abstract | View details | Full text in PDF | Author Info

The northern range of small leaved lime (Tilia cordata Mill.) in Finland has remained the same since the end of 1800s, but according to the studies of subfossiles of lime found in peatlands, the northern limit has once been higher than at the present. The northernmost natural specimens of the species in Reisjärvi do not produce seed, and are therefore probably a relict. The article includes a review on the distribution of the species in Finland and its capacity to regenerate. The natural regeneration of lime in Finland is at present very rare. The species has lost its ability to sexual reproduction, but reproduces readily vegetatively.

The PDF includes a summary in German.

  • Hertz, E-mail: mh@mm.unknown (email)
article id 7036, category Article
I. Lassila. (1920). Tutkimuksia mäntymetsien synnystä ja kehityksestä pohjoisen napapiirin pohjoispuolella. Acta Forestalia Fennica vol. 14 no. 3 article id 7036. https://doi.org/10.14214/aff.7036
English title: Studies on the regeneration and development of Scots pine forests north of the arctic circle.
Original keywords: luontainen uudistuminen; mänty; Pinus sylvestris; siemensato; käpy
English keywords: natural regeneration; cone; seed yield
Abstract | View details | Full text in PDF | Author Info

The frequency of years when Scots pine (Pinus sylvestris L.) produces cones and seeds affects its reproduction in the north. The study area covered most of the pine lands in Northern Finland. Scots pine seems to be able to produce cones relatively often in the north. The amount of seeds produced in one year was, however, not sufficient to produce a dense seedling stand. Thus, the natural pine stands contain usually trees in different ages-classes, which have germinated in different years. The cone production is highest in 150-170 years old trees. Pine also needs warm summers to produce viable seeds. Brush fires avail the growth of seedlings, because they clear of ground vegetation that hinders germination of seeds. The seedlings need also moisture to survive; good regeneration years have often had rainy summers.

The PDF includes a summary in German.

  • Lassila, E-mail: il@mm.unknown (email)
article id 7035, category Article
V. T. Aaltonen. (1920). Use of water of the trees and the moisture conditions in the soil. Acta Forestalia Fennica vol. 14 no. 2 article id 7035. https://doi.org/10.14214/aff.7035
Keywords: regeneration; forest soil; water consumption; use of water; moisture conditions; heathy forests type
Abstract | View details | Full text in PDF | Author Info

The data has been collected in the dry heathy forests in Harjavalta commune in south-west Finland and in Sodankylä commune in Lapland in summer time 1918 and 1919. The aim to the study was to find out how does the water consumption of the trees affect the moisture conditions of the soil and how they are linked to the regeneration of the forest.

Trees in one age class have a certain spatial distribution: the greater the distance between trees the older the trees and the smaller the distance, the younger the trees. This seem to rather be due to the development of the root system and the nutrition intake of a tree than the competition for light. The moisture content of the upper soil layers is higher in the open areas than in the closed canopy stands. Hence there are more seedlings growing in open areas.   However, it is not clear whether the results apply for other forest site types as well, and more research is needed.     

  • Aaltonen, E-mail: va@mm.unknown (email)
article id 7024, category Article
August Renvall. (1919). Suojametsäkysymyksestä IV. Poronlaidunnan järjestely suojametsäalueella. Acta Forestalia Fennica vol. 11 no. 4 article id 7024. https://doi.org/10.14214/aff.7024
English title: Protection forests IV.
Original keywords: luontainen uudistuminen; mänty; Pinus sylvestris; metsäraja; poronhoito
English keywords: natural regeneration; Scots pine; grazing; timber line; reindeer
Abstract | View details | Full text in PDF | Author Info

This fourth part of the six-article series about protection forest in the Northern Finland is a proposal for organizing reindeer grazing to enable scots pine (Pinus sylvestris L.) regeneration near the timber line. Protection forests in the Northern Finland cover third of the natural pastures of reindeer in the area. In these areas reindeer grazing can harm the young pine seedlings. The proposal suggests temporary restrictions in grazing in the coniferous forests. Also, in the northernmost parts of Lapland the pine timberline area would be used only as winter pastures. Regional limits should be set for the number of reindeer. Also the ownership of reindeer herds and herding coopearatives included problematic issues that should be solved.

The article is divided in six parts. A German summary is in a separate PDF.

  • Renvall, E-mail: ar@mm.unknown (email)
article id 7022, category Article
August Renvall. (1919). Suojametsäkysymyksestä II. Suojametsäjärjestelmän tarkoitusperät ja edellytykset. Acta Forestalia Fennica vol. 11 no. 2-3 article id 7022. https://doi.org/10.14214/aff.7022
English title: Protection forests II.
Original keywords: luontainen uudistuminen; mänty; Pinus sylvestris; metsäraja
English keywords: natural regeneration; Scots pine; timber line
Abstract | View details | Full text in PDF | Author Info

The second part of the six-article series about protection forest in Northern Finland outlines the principles of protecting Scots pine (Pinus sylvestris L.) timber line. The protected areas should include at least all of the viable pine stands and those birch (Betula sp.) lands that are necessary to safeguard fuel wood supply in the pine forest zone. Outside the actual pine forest zone also those birch stands that are near populated regions should be protected to secure sustainable fuel wood supply. Third, south and down of the pine forest zone should be protected pine forest stands and adjacent open fell areas where forests are especially vulnerable. A new protection forest commission should be established to execute the protection forest legislation.

The article is divided in six parts. The parts II and III of the article series are included in the same PDF. A German summary is in a separate PDF.

  • Renvall, E-mail: ar@mm.unknown (email)
article id 7088, category Article
Uunio Saalas. (1919). Kaarnakuoriaisista ja niiden aiheuttamista vahingoista Suomen metsissä. Acta Forestalia Fennica vol. 10 no. 1 article id 7088. https://doi.org/10.14214/aff.7088
English title: Bark beetles and insect damages in Finnish forest.
Original keywords: kaarnakuoriaiset; hyönteistuho; entomologia
English keywords: forest pests; Tomicus piniperda; insect damage; Pityogenes chalcographus; Ips typographus; entomology; Scolytus Ratzburgi
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to investigate the abundance of bark beetle species and their damage in Finland. The bark beetle populations were studied in several areas in Finland, both in sites with known beetle damage and without. Two-meter wide lines were measured in the sample plots, where all trees were studied for bark beetle damage in the stem and the crown of the trees. The abundance of bark beetle species and the beetle damages in 25 study areas, and 52 different species are discussed in detail.

Divided by their lifestyle, the most important groups of bark beetles are the pine shoot beetles (Tomicus sp.), beetles reproducing in Scots pine (Pinus sylvestris L.) stems and branches under the bark, beetles reproducing in Norway spruce (Picea abies (L.) H. Karst.) stems and branches under the bark, beetles living in the other coniferous trees, beetles reproducing in roots, beetles reproducing under the Betula sp. bark, beetles reproducing in other deciduous trees and beetles reproducing inside of the stems. Of individual species, Blastophagus piniperda (now Tomicus piniperda) and B. minor cause worst damage to pine and Ips typographus (L.) and Pityogenes chalcographus (L.) to spruce. Serious damage is caused also by Xyloterus lineatus to coniferous trees, Polygraphus polygraphus and P. subopacus to Norway spruce and Scolytus Ratzburgi to Betula sp.

The PDF includes a summary in German.
  • Saalas, E-mail: us@mm.unknown (email)
article id 7018, category Article
Olli Heikinheimo. (1917). Metsänhävityksen ja polton vaikutuksesta metsämaahan. Acta Forestalia Fennica vol. 8 no. 3 article id 7018. https://doi.org/10.14214/aff.7018
English title: Effects of forest devastation and shifting cultivation on forest soil.
Original keywords: maaperä; metsittyminen; kaskeaminen
English keywords: regeneration; soil; shifting cultivation
Abstract | View details | Full text in PDF | Author Info

Soil of open and forest covered lands have different properties. Forest devastation has negative effect on forest soil, for instance, through leaching of nutrients. There are different views on how forest fire influences chemical properties of the soil. Burning of forests can have both positive and negative consequences.

The article publishes partial results from a study that aimed to find out how shifting cultivation affects the soil, and how it may change natural regeneration and forest growth of the stands. Soil samples were collected from four burnt-over sites. Of the samples, size classes of the soil particles, volatile solids and nutrient contents were determined. According to the results, the burning increased soluble nutrients, but the effect was not long-lasting. However, more sample sites would be needed to give definitive results of the differences.

  • Heikinheimo, E-mail: oh@mm.unknown (email)
article id 7013, category Article
Lauri Ilvessalo. (1917). Tutkimuksia mäntymetsien uudistumisvuosista Etelä- ja Keski-Suomessa. Acta Forestalia Fennica vol. 6 no. 2 article id 7013. https://doi.org/10.14214/aff.7013
English title: Studies on the regeneration years of Scots pine forests in Southern and Central Finland.
Original keywords: luontainen uudistuminen; uudistuminen; siemensato; siemenvuosi
English keywords: natural regeneration; seed production; seed year
Abstract | View details | Full text in PDF | Author Info

The success of natural regeneration of Scots pine (Pinus sylvestris L.) is dependent on the amount and quality of seeds produced in each year. While seed production of Scots pine in Northern Finland is well known, there is little information about frequency of good seed years in Southern and Central Finland. The success of regeneration of Scots pine was studied by defining from the growth rings of felled sample trees in which year they started to grow. The aim was to choose sample trees so that they would form a continual series from seedlings to 100 years old trees. In the material there was too little sample trees from certain years. However, within the period of 1827-1910 it could be identified 13 good regeneration years of pine in Southern Finland. According to the study, pine has regenerated very well every 6th year and at least moderately well every 4th year. When compared to the previous studies made in Northern Finland, part of the good regeneration years seems to be same both in Northern and Southern Finland. Regeneration of Scots pine is affected also by the type and condition of the site.

The PDF includes a summary in German.

  • Ilvessalo, E-mail: li@mm.unknown (email)
article id 7512, category Article
Mauno Pesonen, Arto Kettunen, Petri Räsänen. (1995). Non-industrial private forest landowners’ choices of timber management strategies. Acta Forestalia Fennica no. 250 article id 7512. https://doi.org/10.14214/aff.7512
Keywords: forest owners; timber management strategies; genetic algorithm; strategic decision making
Abstract | View details | Full text in PDF | Author Info

The factors affecting the non-industrial, private forest owners’ (NIPF) strategic decisions in management planning are studied. A genetic algorithm is used to induce a set of rules predicting potential cut of the forest owners’ choices of preferred timber management strategies. The rules are based on variables describing the characteristics of the landowners and their forest holdings. The predictive ability of a genetic algorithm is compared to linear regression analysis using identical data sets. The data are cross-validated seven times applying both genetic algorithm and regression analyses in order to examine the data-sensitivity and robustness of the generated models.

The optimal rule set derived from genetic algorithm analyses included the following variables: mean initial volume, forest owner’s positive price expectations for the next eight years, forest owner being classified as farmer, and preference for the recreational use of forest property. When tested with previously unseen test data, the optimal rule set resulted in a relative root mean square error of 0.40.

In the regression analyses, the optimal regression equation consisted of the following variables: mean initial volume, proportion of forestry income, intention to cut extensively in future, and positive price expectations for the next two years. The R2 of the optimal regression equation was 0.3 and the relative root mean square error from the test data 0.38.

In both models, mean initial volume and positive stumpage price expectations were entered as significant predictors of potential cut of preferred timber management strategy. When tested with complete data set of 201 observations, both the optimal rule set and the optimal regression model achieved the same level of accuracy.

  • Pesonen, E-mail: mp@mm.unknown (email)
  • Kettunen, E-mail: ak@mm.unknown
  • Räsänen, E-mail: pr@mm.unknown
article id 7506, category Article
Eero Kubin, Lauri Kemppainen. (1994). Effect of soil preparation of boreal spruce forest on air and soil temperature conditions in forest regeneration areas. Acta Forestalia Fennica no. 244 article id 7506. https://doi.org/10.14214/aff.7506
Keywords: soil preparation; soil temperature; forest regeneration; air temperature; boreal spruce forest
Abstract | View details | Full text in PDF | Author Info

The effect of scarification, ploughing and cross-directional ploughing on temperature conditions in the soil and adjacent air layer have been studied during 11 growth periods by using an unprepared clear-cut area as a control site. The development of seedling stand was followed to determine its shading effect on the soil surface.

Soil preparation decreased the daily temperature amplitude of the air at the height of 10 cm. The maximum temperatures on sunny days were lower in the tilts of the ploughed and in the humps of the cross-directional ploughed sites compared with the unprepared area. Correspondingly, the night temperatures were higher and so the soil preparation reduced the risk of night frost. In the soil at the depth of 5 cm, soil preparation increased daytime temperatures and reduced night temperatures compared with unprepared area. The maximum increase in monthly mean temperatures was almost 5°C, and the daily variation in the surface parts of the tilts and humps increased so that excessively high temperatures for the optimal growth of the root systems were measured from time to time. The temperature also rose at the depths of 50 and 100 cm.

Soil preparation also increased the cumulative temperature sum. The highest sums accumulated during the summer months were recorded at the depth of 5 cm in the humps of cross-directional ploughed area (1,127 dd.) and in the tilts of the ploughed area (1,106 dd.), while the corresponding figure in the unprepared soil was 718 dd. At the height of 10 cm the highest temperature sum was 1,020 dd. in the hump, and 925 dd. in the unprepared area.

The incidence of high temperature amplitudes and frequency of high temperatures at the depth of 5 cm decreased most rapidly in the humps of cross-sectional ploughed area and the ploughing tilts towards the end of the study period. The decrease was attributed principally to the compressing of tilts, the ground vegetation succession and the growth of seedlings. The difference between the prepared and unprepared area did not diminish. The increase in temperature due to soil preparation, thus, lasted at least over 10 years.

  • Kubin, E-mail: ek@mm.unknown (email)
  • Kemppainen, E-mail: lk@mm.unknown
article id 7656, category Article
Kari Leinonen, Matti Leikola, Antti Peltonen, Pentti Räsä­nen. (1989). Kuusen luontainen uudistaminen Pirkka-­Hämeen metsälautakunnassa. Acta Forestalia Fennica no. 209 article id 7656. https://doi.org/10.14214/aff.7656
English title: Natural regeneration of Norway spruce in Pirkka-Häme Forestry Board District, Southern Finland.
Original keywords: kuusi; luontainen uudistaminen; taimettuminen; suojuspuumenetelmä
English keywords: Picea abies; natural regeneration; shelterwood method; restocking
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to evaluate and develop the use of natural regeneration of Norway spruce (Picea abies (L.) H. Karst.) in private forestry. The study was carried out using a line-plot survey with permanent circular sample plots. In total 40 regeneration sites were measured. The study includes results from three successive inventories: prior to the shelterwood cutting, in the summer after the cutting, and one year after the cutting. Regression and logistic regression analyses were used to construct models describing the effect of various factors on the restocking of the stands.

The standing volume prior to the shelterwood cutting was on average 236 m3/ha (ranging from 80 to 428 m3/ha) and after the cutting 120 m3/ha (39–220 m3/ha). The average number of stems per hectare decreased from 435 to 186. Prior to the shelterwood cutting 22% of the stands were satisfactorily restocked. After the cutting and one year later these percentages were 6 and 29%, respectively. Prior to the shelterwood cutting the number of acceptable seedlings was 1,440/ha, in the summer and year later 1,308/ha and 1,546/ha, respectively. Prior to the shelterwood cutting the characteristics of the mother stands did not correlate well with the number of seedlings. The change in the number of seedlings during the initial stage of shelterwood method depended on height of the seedling stand, amount of logging waste and number of germlings prior to the cutting. The risk to fail in regeneration was highest in the poorly restocked, sparse shelterwood stands, where a fast expansion of grass vegetation took place.

The PDF includes a summary in English.

  • Leinonen, E-mail: kl@mm.unknown (email)
  • Leikola, E-mail: ml@mm.unknown
  • Peltonen, E-mail: ap@mm.unknown
  • Räsä­nen, E-mail: pr@mm.unknown
article id 7647, category Article
Shikui Peng. (1987). On the combination of multitemporal satellite and field data for forest inventories. Acta Forestalia Fennica no. 200 article id 7647. https://doi.org/10.14214/aff.7647
Keywords: stratification; SPR; two phase sampling; generalized least squares; multitemporal
Abstract | View details | Full text in PDF | Author Info

The study concerns with the methodology and efficiency of integrating multitemporal satellite image data with permanent sample plots in a continuous forest inventory and compartment wise estimation. The generalized least squares estimation for the population, and the unsupervised stratification for compartments, are the main estimation methods employed. The experimental material is composed of real and simulated multitemporal images (Landsat TM) and field data. Precision analyses for the estimation and comparisons for a number of estimation and updating methods, as well as statistical options are given.

The PDF includes a summary in Finnish.

  • Peng, E-mail: sp@mm.unknown (email)
article id 7642, category Article
Alpo Luomajoki. (1986). Timing of microsporogenesis in trees with reference to climatic adaptation: a review. Acta Forestalia Fennica no. 196 article id 7642. https://doi.org/10.14214/aff.7642
Keywords: photoperiod; annual cycle; heat sum; microsporogenesis; meiosis; tetrad
Abstract | View details | Full text in PDF | Author Info

The timing of the tetrad phase of microsporogenesis in sixteen tree species, belonging to the genera of Abies, Larix, Picea, Pinus, Alnus, Betula, Corylus and Populus, was studied. The tetrad phase of microsporogenesis in conifers and in Populus tremula L. was reached from late March to early June including the yearly and latitudinal variation. The tetrad phase in Betulaceae was reached in late July to mid-August. The microsporogenesis in Betulaceae species differed in ecophysiological terms from the other species studied in that the timing in Betulaceae was rather day-length dependent than heat sum-correlated. In conifers and in Populus the timing of tetrad phase correlated with heat sums accumulated and did not correlate with day length or any kind of thermal threshold. This difference was, however, judged to be associated to seasonal adaptive strategies rather than taxonomic relationships.

The PDF includes a summary in Finnish.

  • Luomajoki, E-mail: al@mm.unknown (email)
article id 7625, category Article
Antti Turakka, Olavi Luukkanen, Suree Bhumibhamon. (1982). Notes on Pinus kesiya and P. merkusii and their natural regeneration in watershed areas of northern Thailand. Acta Forestalia Fennica no. 178 article id 7625. https://doi.org/10.14214/aff.7625
Keywords: forest fires; natural regeneration; Pinus kesiya; Thailand; Pinus mercusii
Abstract | View details | Full text in PDF | Author Info

The aim of the present work was to clarify the structure of selected natural Pinus kesiya Royale ex Gord. And P. merkusii Jungh. et de Vriese stands, with particular attention on the amount and quality of naturally-occurring seedlings and young trees. Furthermore, basic information required in the management of pine stands in watershed areas of northern Thailand was obtained.

Large number of pine seedlings were found in P. kesiyana stands only. Two of the examined four localities where this species occurred also included various intermediary height classes under the mature trees. In dense stands the number of seedlings was generally smaller as compared with lower seed tree densities. Neither one of the two localities where P. Merkusii was investigated indicated sufficient natural regeneration. Young pines (over 5 m height) seemed to survive the frequent ground fires quite well, whereas younger seedlings were destroyed and the ground layer vigour was lowered in these cases.

In situ sowing experiments at the beginning of the dry season indicated a faster development and better survival of emerging P. Kesiya seedlings as compared to P. Merkusii. Soil preparation and exposure to sun decreased the survival of seedlings in both species. Utilization of natural regeneration and direct sowing of pines as a silvicultural method as well as the general significance of the two pine species in the succession of plant communities under the influence of forest fires is also discussed.

The PDF includes a summary in Finnish.

  • Turakka, E-mail: at@mm.unknown (email)
  • Luukkanen, E-mail: ol@mm.unknown
  • Bhumibhamon, E-mail: sb@mm.unknown
article id 7620, category Article
Min-Sup Chung. (1981). Biochemical methods for determining population structure in Pinus sylvestris L. Acta Forestalia Fennica no. 173 article id 7620. https://doi.org/10.14214/aff.7620
Keywords: Scots pine; tree breeding; Finland; genetic variation; population structure; plus trees; self-fertilization
Abstract | View details | Full text in PDF | Author Info

Studies on Finnish Scots pine (Pinus sylvestris L.) plus tree clones by monoterpene and isozyme analyses was undertaken to further investigate mating system, population structure and pollination. Six allozyme systems (3 GOT, 1 GDH and 2 LAP) were properly analysed on the basis of segregation. Monoterpenes were analysed from needle material and segregation in high and low 3-carene content was found to depend on two alleles C and c. Thus, six allozyme systems and one monoterpene system were used as markers in this study.

It was shown that the northern clonal group maintains a much genetic variation as the central or southern clonal groups. The conditional probability of self-fertilization in about 20-year old clones estimated by the multilocus model was 14.1%, of which 8% originate from mating between trees that carry the same alleles to one of the maternal parent at some loci and 6% through self-fertilization.

There was no prominent difference in allele frequency of male gametes that pollinated the very early or very late flowering clones. The northern clonal group has higher a lower frequency of alleles GOT B2 and B3 respectively than of the southern clonal groups. The artificial plus tree selection, particularly in northern Finland, appears to favour heterozygous genotypes for the alleles that control 3-carene content n Scots pine.

The PDF includes a summary in Finnish.

  • Chung, E-mail: mc@mm.unknown (email)
article id 7575, category Article
Robert T Brown, Peitsa Mikola. (1974). The influence of fruticose soil lichens upon the mycorrhizae and seedling growth of forest trees. Acta Forestalia Fennica no. 141 article id 7575. https://doi.org/10.14214/aff.7575
Keywords: Pinus sylvestris; Norway spruce; Betula pendula; Picea abies; regeneration; Scots pine; lichens; Cladonia alpestris; Cladonia rangiferina; Cladonia arbuscula; Cladonia pleurota; Cetraria islandica; Stereocaulon paschale; growth inhibition
Abstract | View details | Full text in PDF | Author Info

Water extracts of six common soil lichens, Cladonia alpestris, C. rangiferina, C. arbuscula (sylvatica), C. pleurota, Cetraria islandica, Stereocaulon paschale, inhibited growth of ectomycorrhizae of Pinus sylvestris (L.). Of 17 fungi (12 mycorrhizal) tested, many were inhibited while others were scarcely influenced or even occasionally stimulated by the extracts. Cladonia alpestris extract inhibited most fungi while C. rangiferina showed much less influence.

In pure culture synthesis experiments, 32P uptake of Pinus sylvestris was significantly reduced by C. alpestris extract. Different species of fungi showed widely variant abilities to pick up 32 P. in nursery experiments, much more vigorous growth of P. sylvestris and Picea abies (L.) H. Karst. was obtained on plots without C. alpestris than on paired plots covered with it. Betula verrucosa (B. pendula Roth) showed no difference. Under natural forest conditions, P. sylvestris seedlings grow much more rapidly where C. alpestris had been eliminated by road building or reindeer grazing than do seedlings only one meter distant under undisturbed C. alpestris cover. It is suggested that by properly controlled reindeer grazing, establishment and early growth of P. sylvestris on Cladonia sites can be much enhanced. By the time that C. alpestris could become re-established the pine seedlings would have grown large enough to suffer little from reindeer grazing. This study shows the continuity of the major components of the forest tundra biome – the dependence of pines, mycorrhizae, lichens, and reindeer and their predators (human or otherwise) upon each other for a healthy existence.

The PDF includes a summary in Finnish.

  • Brown, E-mail: rb@mm.unknown (email)
  • Mikola, E-mail: pm@mm.unknown
article id 7561, category Article
Kalervo Salonen. (1973). On the life cycle, especially on the reproduction biology of Blastophagus piniperda L. ( Col., Scolytidae). Acta Forestalia Fennica no. 127 article id 7561. https://doi.org/10.14214/aff.7561
Keywords: regeneration; Tomicus piniperda; swarming; egg galleries; Blastophagus piniperda
Abstract | View details | Full text in PDF | Author Info

Blastophagus piniperda L. (now Tomicus piniperda) life cycle, especially temperature effects at various stages, has been studied in laboratory, outdoor development experiments and in natural conditions in the field in Finland, 1961–1970.

It was established that when a tree with overwintering beetles in its base is felled during the winter, the overwintered insects can establish an egg gallery into the stump without leaving for swarming flight. The egg gallery can be established in this case already about a month before swarming starts. Swarming starts after temperature in the shade exceeds 10° C. It is at its maximum at a temperature over 12° C and in conditions of no wind. The swarming starts in Southern Finland generally in the latter half of April, and in Lapland two to four weeks later than in Southern Finland, and it lasts from a few days to a few weeks. As the temperature rises, the rate of egg gallery construction and the rate of egg laying increase. The characteristics of the galleries and pupal stage are described in detail.

In Finnish conditions, B. Piniperda does not have a diapause. Movement into overwintering sites starts after the minimum daily temperature goes below 0° C. About 10% of the insects found in the overwintering sites in spring were estimated to have died during the winter. With increasing density, the number of new beetles which developed from each egg gallery decreased.

The PDF includes a summary in Finnish.

  • Salonen, E-mail: ks@mm.unknown (email)
article id 7545, category Article
Lalli Laine, Matti Nuorteva. (1970). On the antagonistic influence of insect pathogenic fungi Beauveria bassiana (Bals.) Vuill. and B. tenella (Delacr.) Siem. on root rot disease spongy saprot (Fomes annosus (Fr.) Cooke). Acta Forestalia Fennica no. 111 article id 7545. https://doi.org/10.14214/aff.7545
Keywords: antagonism; root rot; Fomitopsis annosa; insect pathogenic
Abstract | View details | Full text in PDF | Author Info

The article presents the studies about antagonistic influence of insect pathogenic fungi Beauveria bassiana (Bals.) Vuill. and B. tenella (Delacr.) Siem. against root rot diseases. The experiments were conducted in laboratory where the fungi were grown in Petri dishes. The results show that these fungi are antagonistic with each other. The used stem of B. bassiana was proved as strongest antagonist against all studied F.annosus.

The PDF contains a summary in German. 

  • Laine, E-mail: ll@mm.unknown (email)
  • Nuorteva, E-mail: mn@mm.unknown
article id 7607, category Article
Eino Oinonen. (1969). The time table of vegetative spreading of the lily-of-the-valley (Convallaria majalis L.) and the wood small-reed (Calamagrostis epigeios (L.) Roth) in southern Finland. Acta Forestalia Fennica no. 97 article id 7607. https://doi.org/10.14214/aff.7607
Keywords: regeneration; forest fire; Calamagrostis epigeios; lily-of-the-valley; Convallaria majalis; wood small-reed
Abstract | View details | Full text in PDF | Author Info

The purpose of this study has been to compile a time-table for the vegetative spreading o the lily-of-the-valley and the wood small-reed. The diameters of the mainly solitary stands of these species have been compared to stand diameters of bracken (Lycopodium clavatum, L. annotium, and L. complanatum), to tree age determined by basal borings, and to times of fires in the site.

Regeneration of the lily-of-the-valley (Convallaria Majalis L.) and the wood small-reed (Calamagrostis epigeios (L.) Roth) from seed is relatively infrequent, and distance between stands may be considerable. Regeneration is more common after fire. The stands of the species are relatively fire resistant, especially on heathlands, where the subsurface parts are safe in the mineral soil. Large stands are generally due to vegetative spreading.

The rate of vegetative spreading of both of the species is practically constant, and about equal, 12.5 cm/year in diameter and 6.2 cm/year in the radial direction. When the actual regeneration time after the fire is not known, the rate of the spreading can be lower than this number.

  • Oinonen, E-mail: eo@mm.unknown (email)
article id 7187, category Article
Eino Oinonen. (1968). Lycopodium clavatum L.- ja L. annotium L.-kasvustojen laajuus rinnastettuna samanpaikkaisiin L. complanatum L.- ja Pteridium aquilinum (L.) Kuhn -esiintymiin sekä puuston ikään ja paloaikoihin. Acta Forestalia Fennica no. 87 article id 7187. https://doi.org/10.14214/aff.7187
English title: The size of Lycopodium clavatum and L. Annotinum stands as compared to that of L. Complanatum and Pteridium aquilinum stands, the age of the stand and the dates of fire, on the site.
Original keywords: metsäpalo; uudistuminen; kloonit; katinlieko; riidenlieko; lisääntyminen
English keywords: regeneration; forest fire; clones; Pteridium aquilinum; Lycopodium complanatum; Lycopodium clavatum; Lycopodium annotium
Abstract | View details | Full text in PDF | Author Info

The present study is a part of larger project into the size and age of certain forest plants. This study seeks to confirm the size-age relationship of Lycopodium clavatum L. and L. annotium L. stands, and the time of sporal regeneration. The stand dimensions were plotted against the size of bracken (Pteridium aquilinum (L.) Kuhn) and ground pine (Lycopodium complanatum L.) stands growing on the same site, and against the age of the timber and the time of fire on the site.

The method based on parallel measurements carried out in burned forests has proved to be suitable for establishing the rate of spreading of stands and their age. The three club-moss species proved to be much alike in their sporal regeneration. They, as well as bracken, regenerate under the condition created by fire. The largest detached patches are often clones. Both Lycopodium clavatum and L. annotium survive fire poorly. Thus, the maximum size of the clones is usually connected with the last forest fire. Pieces of the shoots may survive the fires.

Sporal regeneration of these species also occur without the aid of fire. As also variation in the annual growth of the shoots can be considerable, the stand size of these species is not as good indicator of the date of fire as with Pteridium aquilinum and L. complanatum. The winding appearance of the shoots increases the error in determination of stand age by the stand size further.

The results emphasize the importance of taking into account the time and spread of the plants in the traditional vegetation analysis. A central question is: what is an individual.

The PDF includes a summary in English.

  • Oinonen, E-mail: eo@mm.unknown (email)

Category : Research article

article id 23045, category Research article
Laura Pikkarainen, Harri Strandman, Eerik Vento, Aaron Petty, Olli-Pekka Tikkanen, Antti Kilpeläinen, Heli Peltola. (2024). Effects of forest conservation and management on timber, ecosystem carbon, dead wood and habitat suitability area in a boreal forest under climate change. Silva Fennica vol. 58 no. 2 article id 23045. https://doi.org/10.14214/sf.23045
Keywords: saproxylic species; simulation; carbon storage; forest fertilization; Fennoscandia; forest ecosystems services; improved regeneration material
Highlights: Increasing forest conservation areas increased all other ecosystem services except timber yield. Intensive forest management enhanced this increase; Increased conservation area decreased timber yield, but intensive forest management reduced this effect and even overcompensated it at the end of simulation period in the 10% conservation scenario with intensified forest management; Climate change increased all other ecosystem services, except carbon stocks.
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We used forest ecosystem model simulations to study how forest conservation and management intensity affected timber yield, ecosystem carbon stocks, amount of dead wood, and habitat suitability area in a middle boreal forest region of Finland under changing climate over a 90-year simulation period. We used the following forest conservation and management scenarios: baseline forest management (BM), BM with 10 or 20% increase of conservation area with or without intensified forest management (i.e. improved forest regeneration material and forest fertilization). The simulations were done under current climate (reference period of 1981–2010), and Representative Concentration Pathway (RCP) climate change projections under the RCP2.6 and RCP4.5 forcing scenarios. Overall, increasing the forest conservation area decreased timber yield and increased the ecosystem carbon stock, the amount of dead wood and consequently the area of suitable habitat for saproxylic species. The use of intensified forest management reduced the loss of timber yield, increased ecosystem carbon stock, the amount of dead wood and area of suitable habitat for saproxylic species. At the end of simulation period, the use of intensified forest management even overcompensated (4–6% higher) the timber loss from 10% increase of conservation area. Under changing climate, timber yield, the amount of dead wood and the area of suitable habitats for saproxylic species increased. To conclude, with intensified forest management it is possible, in the short term, to decrease the loss of timber yield through increased forest conservation area and in the long term maintain or even increase it compared to baseline forest management.

  • Pikkarainen, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland ORCID https://orcid.org/0000-0001-5301-3639 E-mail: laura.pikkarainen@uef.fi (email)
  • Strandman, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland ORCID https://orcid.org/0000-0002-9400-6424 E-mail: harri.strandman@uef.fi
  • Vento, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland E-mail: eerik.vento@gmail.com
  • Petty, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland ORCID https://orcid.org/0009-0006-6595-1386 E-mail: aaron.petty@uef.fi
  • Tikkanen, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland ORCID https://orcid.org/0000-0002-3875-2772 E-mail: olli-pekka.tikkanen@uef.fi
  • Kilpeläinen, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland ORCID https://orcid.org/0000-0003-4299-0578 E-mail: antti.kilpelainen@uef.fi
  • Peltola, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland E-mail: heli.peltola@uef.fi
article id 23072, category Research article
Matti Haapanen. (2024). Realised genetic gains from past Finnish silver birch seed orchards. Silva Fennica vol. 58 no. 1 article id 23072. https://doi.org/10.14214/sf.23072
Keywords: Betula pendula; seed orchards; genetic gain; forest reproductive materials
Highlights: Seed orchard materials generally outperformed unimproved trees in all growth and quality traits, but individual seed orchards showed substantial performance variability; Realised gains in stem volume and forking showed an increasing temporal trend, whereas gains in branch quality were positive and steady; Gains in stem volume and branch quality trade off slightly; The bi-clonal seed orchard variety “JR-2” emerged as the best overall performer across all the seed orchards, whereas the older variety “JR-1” was mediocre; An alternative statistical concept, D-value, was introduced to compare levels of genetic gains for different scaled, normally distributed traits.
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Genetic gains realised through silver birch (Betula pendula Roth) seed orchards were studied using data from common-garden trials established at 34 sites in southern and central Finland. The test materials include seedlots representing 19 commercial seed orchards that operated between 1972 and 2009, and 21 natural stands. All the trials were assessed for several growth and quality traits between the ages of 9 and 24. Realised gains were estimated based on univariate linear mixed models with corrections for latitudinal seed transfer effects. Overall, seed orchard materials outperformed unimproved reference materials in all the traits but results for individual seed orchards varied substantially. Stem volume gains ranged from 1.0% to 31.1%. Improved trees had, on average, 6.8% (up to 26.7%) fewer ramicorn branches and 16.2% (up to 57.6%) fewer forks than unimproved trees. Branch and overall quality showed consistently positive gains. More recently established seed orchards performed better than older ones, and seed orchards with fewer clones outperformed those with dozens of clones. "JR-1" and "JR-2" bi-clonal seed orchards fared differently, with "JR-1" showing modest genetic gains and "JR-2" emerging as the top overall performer across all seed orchards. An alternative statistical concept, the D-value, was utilised to assess the magnitude of genetic gain for different scaled, normally distributed traits. Average D-values implied a similar level of improvement for stem volume, branch quality, and forking, and a smaller gain for stem slenderness and the number of ramicorn branches. The results for individual seed orchards suggest a slight trade-off between stem volume growth and branch quality.
article id 23004, category Research article
Per Nordin, Erika Olofsson, Karin Hjelm. (2023). Within-site adaptation: growth and mortality of Norway spruce, Scots pine and silver birch seedlings in different planting positions across a soil moisture gradient. Silva Fennica vol. 57 no. 3 article id 23004. https://doi.org/10.14214/sf.23004
Keywords: regeneration; microsite; decision making; mounding; planting; depth-to-water
Highlights: A soil moisture map could be used to support the choice of planting position for different soil moisture conditions; Mounds reduced mortality rates for conifers when conditions were wet, but at drier conditions differences between planting positions were small; Contradictory, silver birch had higher survival in lower planting positions compared with mounds; Height and diameter were higher in mounds for conifers, but only small differences occurred between planting positions for silver birch.
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Adapting to site conditions is a central part of forest regeneration and can be done through selection of different planting positions. Requirements are tree species specific, and the use of soil moisture maps could be a way to support decision making in forest regeneration planning. At two experimental sites with varying soil moisture conditions in southern Sweden Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and silver birch (Betula pendula Roth) seedlings were planted in four different planting positions following mounding site preparation; Depression, Hinge, Mound and Unscarified. Soil moisture estimates were obtained from a high-resolution depth-to-water raster for each planting spot. The effect of soil moisture, planting position and their interactions on mortality, height and diameter was evaluated for each tree species. In wet conditions mounds proved to be the best option to minimize seedling mortality for conifers, but with decreasing soil moisture, differences between the planting positions decreased. Birch on the other hand had the greatest survival in the hinge. The coniferous species displayed increased height and diameter when planted in mounds independent of the soil moisture conditions, whereas silver birch was less dependent on a specific planting position. Results from this study shows that a soil moisture map can explain mortality, height and diameter and thus can be a useful tool when choosing planting position in different soil moisture conditions.
article id 22013, category Research article
Bodil Häggström, Reimo Lutter, Tomas Lundmark, Fredrik Sjödin, Annika Nordin. (2023). Effect of arginine-phosphate addition on early survival and growth of Scots pine, Norway spruce and silver birch. Silva Fennica vol. 57 no. 2 article id 22013. https://doi.org/10.14214/sf.22013
Keywords: Pinus sylvestris; Betula pendula; Picea abies; forest regeneration; seedling growth; seedling survival; arginine
Highlights: Arginine-phosphate addition (APA) represents a potential tool to aid regeneration of planted trees, especially to increase survival of Scots pine seedlings on sites where susceptible to pests;Effects of APA however varies between different sites.
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Applying arginine-phosphate (AP) to tree seedlings at planting is a novel silvicultural practice in Northern Europe to improve the success of forest regeneration. We present three case-studies of the potential advantages of adding AP at planting on the establishment and damage susceptibility of seedlings in pure and mixed plantings of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst. ) and silver birch (Betula pendula Roth) over two years in the field. Location of study sites were in southern (S), northeastern (NE) and northwestern (NW) Sweden. The main agents of damage were pine weevil (Hylobius abietis L.) on conifers at the south site, browsing of birch at all sites and browsing/other top damage to conifers at the north sites. The effect of adding AP varied between the sites. It was positive for survival of pine at site S, despite considerable damage by pine weevil. However, at the S site more of the surviving spruce and birch were browsed when treated with AP. At the NE site AP-treatment had positive effects on conifer growth. At the NW site adding AP positively affected survival and growth of all three species, and AP-treated seedlings of all species were less browsed than untreated seedlings. AP treatment presents a potential tool to improve the success of forest regeneration, especially when establishing pine stands in south Sweden.
  • Häggström, Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden ORCID https://orcid.org/0000-0002-7738-5493 E-mail: bodil.haggstrom@slu.se
  • Lutter, Institute of Forestry and Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu 51006, Estonia ORCID https://orcid.org/0000-0001-5847-4282 E-mail: reimo.lutter@emu.ee
  • Lundmark, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden ORCID https://orcid.org/0000-0003-2271-3469 E-mail: tomas.lundmark@slu.se
  • Sjödin, Unit for field-based forest research, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden E-mail: fredrik.sjodin@slu.se
  • Nordin, Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden ORCID https://orcid.org/0000-0002-5765-3550 E-mail: annika.nordin@slu.se
article id 10762, category Research article
Karri Uotila, Jaana Luoranen, Timo Saksa, Tiina Laine, Juha Heiskanen. (2022). Long-term growth response of Norway spruce in different mounding and vegetation control treatments on fine-textured soils. Silva Fennica vol. 56 no. 4 article id 10762. https://doi.org/10.14214/sf.10762
Keywords: boreal forest; establishment; regeneration; site preparation; plantation; tree growth; scarification; fine-textured soils; mechanical vegetation control
Highlights: Spot and ditch mounding methods favoured spruce sapling development on fine-textured soils; Inverted and unprepared plots showed the weakest growth; Vegetation control suppressed the growth differences between site preparation methods; Vegetation control reduced the density of resprouts after early cleaning.
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Mechanical site preparation (MSP) is a common practice that precedes the planting of Norway spruce (Picea abies (L.) H. Karst.) in Nordic forests. Mounding has become the most used method in spruce planting in recent years. This study examined the effects of different mounding treatments (spot and ditch mounding, inversion, unprepared control with or without herbicide application) and a mechanical vegetation control (MVC) treatment done 3–4 years after planting on the post-planting growth of spruce container seedlings and their development to saplings during the first 11–13 years on two forest till soils in central Finland, one on flat terrain and other on a southwest slope. On these fine-textured soils the spot and ditch mounding methods favoured spruce saplings development. Inversion and unprepared plots showed weakest growth. On the site with flat terrain, 11 years post planting, spruce saplings were 78–144 cm (38–80%) taller and their breast height diameters were 11–13 mm (60–74%) thicker for ditch or spot mounding than for inversion or herbicide treatment. On the site with sloped terrain the differences were minor between the MSP treatments. MVC improved spruce height growth on sites which did not have intensive MSP, especially on control saplings planted on unprepared soil in herbicide and inversion treatments. On the flat terrain, MVC reduced the density of resprouts to be removed later in pre-commercial thinning. As a conclusion, spot or ditch mounding favoured the growth of spruce over inversion especially on flat terrain with fine-textured soil.

  • Uotila, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: karri.uotila@luke.fi (email)
  • Luoranen, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID https://orcid.org/0000-0002-6970-2030 E-mail: jaana.luoranen@luke.fi
  • Saksa, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID https://orcid.org/0000-0002-1776-2357 E-mail: timo.saksa@luke.fi
  • Laine, Metsä Forest, Revontulenpuisto 2, FI-02100 Espoo, Finland ORCID https://orcid.org/0000-0002-6448-8274 E-mail: tiina.laine@metsagroup.com
  • Heiskanen, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID https://orcid.org/0000-0002-0549-835X E-mail: juha.heiskanen@luke.fi
article id 10544, category Research article
Lars Sprengel, Heinrich Spiecker, Shuirong Wu. (2022). Two subject specific modelling approaches to construct base-age invariant polymorphic site index curves with varying asymptotes. Silva Fennica vol. 56 no. 1 article id 10544. https://doi.org/10.14214/sf.10544
Keywords: generalized algebraic difference approach; stem analysis; dummy variable approach; gnls; nonlinear mixed-effects models; nlme; Zhongtiaoshan forest region
Highlights: Base-age invariant families of height growth curves with polymorphism and varying asymptotes are presented for the seven economically most important tree species in Zhongtiaoshan forest region, China; The nonlinear fixed-effects approach outperforms the nonlinear mixed-effects approach according to the AIC, but according to RMSE and bias these results are not fully supported.
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For constructing growth and yield models the concept of site index as measure of productivity is crucial. Here, we use nonlinear mixed-effects models (NLME) with random individual effects and nonlinear models with dummy variables as fixed individual effects (NLFE) to fit mechanistic growth functions to stem analysis data of the economically most important tree species in Zhongtiaoshan forest region, China. The Richards and Lundqvist function are formulated into five dynamic equations (R1, R2, L1, L2 and L3) applying the generalized algebraic difference approach (GADA), which inherit polymorphism, varying asymptotes and base-age invariance. According to Akaike information criterion the R1 model as NLFE fits height growth data of Pinus tabuliformis Carrière, Pinus armandii Franch., Quercus liaotungensis Koidz., Quercus aliena Blume and Betula platyphylla Sukaczev best, while for Quercus variabilis Blume R2 as NLFE fits height growth data best. For Larix principis-rupprechtii Mayr L1 as NLME has been selected as best model, as R1 and R2 both as NLFE and NLME are not extrapolating the comparably short length of height growth data well enough. However, according to the root mean square error and bias differences between model fits of both the selected equation and the chosen model fitting approach are not so clear. Presented families of height growth curves serve as planning tools to identify site index and therefore assess productivity of forest stands in the studied region. A direct comparison of the productivity of forest stands of the same tree species is possible due to base-age invariance of the selected models.

  • Sprengel, Chair of Forest Growth and Dendroecology, Albert-Ludwigs-University Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany ORCID https://orcid.org/0000-0002-6332-7911 E-mail: lars.sprengel@iww.uni-freiburg.de (email)
  • Spiecker, Chair of Forest Growth and Dendroecology, Albert-Ludwigs-University Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany E-mail: instww@uni-freiburg.de
  • Wu, Research Institute of Forest Policy and Information, Chinese Academy of Forestry, No. 1 Dongxiaofu, Haidian District, Beijing 100091, China E-mail: shuirongwu@126.com
article id 10512, category Research article
Mateusz Liziniewicz, Ignacio Barbeito, Andis Zvirgzdins, Lars-Göran Stener, Pentti Niemistö, Nils Fahlvik, Ulf Johansson, Bo Karlsson, Urban Nilsson. (2022). Production of genetically improved silver birch plantations in southern and central Sweden. Silva Fennica vol. 56 no. 1 article id 10512. https://doi.org/10.14214/sf.10512
Keywords: Betula pendula; planting; generalized algebraic difference approach; genetic gain; stand basal area starting function
Highlights: The basal area development of genetically improved birch in Sweden was modeled using a generalized algebraic difference approach; The best model fit, both graphically and statistically was delivered by the Korf base model; The analysis of realized gain trial showed a stability of relative differences in basal area between tested genotypes.
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Investing in planting genetically improved silver birch (Betula pendula Roth) in Swedish plantations requires understanding how birch stands will develop over their entire rotation. Previous studies have indicated relatively low production of birch compared to Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). This could result from using unrepresentative basic data, collected from unimproved, naturally-regenerated birch (Betula spp.) growing on inventory plots often located in coniferous stands. The objective of this study was to develop a basal area development function of improved silver birch and evaluate production over a full rotation period. We used data from 52 experiments including planted silver birch of different genetic breeding levels in southern and central Sweden. The experimental plots were established on fertile forest sites and on former agricultural lands, and were managed with different numbers of thinnings and basal area removal regimes. The model best describing total stand basal area development was a dynamic equation derived from the Korf base model. The analysis of the realized gain trial for birch showed a good stability of the early calculated relative differences in basal area between tested genotypes over time. Thus, the relative difference in basal area might be with cautious used as representation of the realized genetic gain. On average forest sites in southern Sweden, improved and planted silver birch could produce between 6–10.5 m3 ha–1 year–1, while on fertile agriculture land the average productivity might be higher, especially with material coming from the improvement program. The performed analysis provided a first step toward predicting the effects of genetic improvement on total volume production and profitability of silver birch. However, more experiments are needed to set up the relative differences between different improved material.

  • Liziniewicz, The Forestry Research Institute of Sweden, Ekebo, SE-268 90 Svalöv, Sweden E-mail: mateusz.liziniewicz@skogforsk.se
  • Barbeito, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp, Sweden; Université de Lorraine, AgroParisTech, INRAE, UMR Silva, Nancy, France E-mail: ignacio.barbeito@slu.se
  • Zvirgzdins, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Box 49, 23053 Alnarp, Sweden E-mail: andis.zvirgzdins@slu.se (email)
  • Stener, The Forestry Research Institute of Sweden, Ekebo, SE-268 90 Svalöv, Sweden E-mail: lg.stener@telia.com
  • Niemistö, Natural Resources In-stitute Finland (Luke), Natural resources, Seinäjoki, Finland E-mail: pentti.niemisto@luke.fi
  • Fahlvik, The Forestry Research Institute of Sweden, Ekebo, SE-268 90 Svalöv, Sweden E-mail: nils.fahlvik@skogforsk.se
  • Johansson, Tönnersjöheden Experimental Forest, SLU, Simlångsdalen, Sweden E-mail: ulf.johansson@slu.se
  • Karlsson, The Forestry Research Institute of Sweden, Ekebo, SE-268 90 Svalöv, Sweden E-mail: curly.birch@gmail.com
  • Nilsson, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Box 49, 23053 Alnarp, Sweden E-mail: urban.nilsson@slu.se
article id 10528, category Research article
Jaana Luoranen, Heli Viiri. (2021). Comparison of the planting success and risks of pine weevil damage on mineral soil and drained peatland sites three years after planting. Silva Fennica vol. 55 no. 4 article id 10528. https://doi.org/10.14214/sf.10528
Keywords: survival; planting; mechanical site preparation; ground vegetation; forest regeneration; Hylobius abietis
Highlights: The planting success was poorer on peatland sites than on mineral soil; Dense ground vegetation cover is more probable on peatland than on mineral soil; No differences in pine weevil feeding damage on mineral soil and peatland were found; Cultivated mineral soil reduced the vegetation cover, feeding damage and seedling mortality.
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Over 20% of regeneration operations will be on drained peatland in the next decade in Finland. There are only a few studies comparing the planting success and the risk of pine weevil (Hylobius abetis (L.) feeding damage on mineral soil and drained peatland. Thirty sites planted with Norway spruce (Picea abies (L.) H. Karst.) container seedlings in 2009 in Southern and Central Finland were inventoried three growing seasons after planting. Prediction models for the probability of survival, pine weevil damage and the presence of ground vegetation cover were done separately for peatland and mineral soil sites. The planting success was 17% lower on peatland sites (1379 surviving seedlings ha–1) than on mineral soil (1654 seedlings ha–1). The factors explaining the survival were the ground vegetation cover and type of the planting spot on the peatland, and the ground vegetation cover on mineral soil. On mineral soil, 76% of the planting spots were on cultivated mineral soil while on peatland only 28% of the seedlings were planted on similar spots. There were also fewer seedlings that were surrounded by dense ground vegetation on mineral soil (4%) than on peatland (14%). Pine weevil feeding damage did not differ significantly on peatland (23%) or mineral soil (18%). The more time there was from clear-cutting, the more the probability of pine weevil feeding damage was reduced on both soil classes. Additionally, cover vegetation in the vicinity of the seedlings increased on mineral soil. Cultivated planting spots, especially those covered by mineral soil, prevented pine weevil feeding and reduced the harmful effects of vegetation on the seedlings both on mineral soil and peatland.

article id 10485, category Research article
Felicia Dahlgren Lidman, Emma Holmström, Tomas Lundmark, Nils Fahlvik. (2021). Management of spontaneously regenerated mixed stands of birch and Norway spruce in Sweden. Silva Fennica vol. 55 no. 4 article id 10485. https://doi.org/10.14214/sf.10485
Keywords: Betula pendula; Picea abies; Betula pubescens; natural regeneration; mixed forest; land expectation value
Highlights: The absence of forest management does not always mean economic loss; With dense spontaneous regeneration of birch and Norway spruce, the first competition release can have a high impact on future stem development; Significantly different effects on stand volume production and diameter development of Norway spruce can be expected with different biomass harvest strategies.
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Timber production and profitability were evaluated for spontaneously-regenerated mixtures on two formerly clearcut areas. The abandoned areas developed into birch-dominated (Betula pendula Roth and Betula pubescens Ehrh.) stands with successional ingrowth of Norway spruce (Picea abies (L.) H. Karst.). An experiment with randomized treatments within blocks was established, using three management strategies and one unthinned control, resulting in variation in optimal rotation age, merchantable volume and species composition. The management strategies were evaluated based on total production (volume) by using measured growth data 42 years after clearcutting and the modelled future stand development. The long-term effects of spontaneous regeneration and management strategies were evaluated based on land expectation value (LEV) and compared with a fifth management strategy using artificial regeneration and intense thinnings. 12 years after treatment, at a stand age of 42 years, the unthinned control had produced the highest total stem volume. At interest rates of 2% or higher, the unmanaged forest was an economically viable strategy, even compared to an intensive management strategy with a preferred merchantable timber species. Interest rates clearly impacted the profitability of the different management strategies. This study shows that when spontaneous regeneration is successful and dense, the first competition release can have a high impact on the development of future crop trees and on the species mixture.

article id 10506, category Research article
Mikko Tikkinen, Terhi Latvala, Tuija Aronen. (2021). Interest in vegetatively propagated Norway spruce materials – a survey among Finnish forest owners and professionals. Silva Fennica vol. 55 no. 3 article id 10506. https://doi.org/10.14214/sf.10506
Keywords: Picea abies; desired traits; intention of adoption; somatic embryogenesis; willingness to pay
Highlights: Survey among forest owners and professionals’ perceptions towards tree breeding and vegetative propagation yielded over 3000 responses; Most valued features in reforestation material were: improved resilience in changing climate, improved pest and pathogen resistance, and securing the species’ gene pool; Majority of respondents accepted reforestation with vegetatively propagated material to some extent; Willingness to pay for improved features was indicated.
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Forests and forestry will encounter several changes of unknown magnitude within the coming decades. In the Nordic, long rotations complicate any anticipation to the upcoming changes. Tree breeding can contribute to coping with these changes. The time span of implementing breeding results in practice may be shortened through vegetative propagation. Introducing vegetative propagation to forest regeneration may phase several challenges before adopted by the industry, some of which are related to perceptions about new technology. Firstly, private forest owners are in a key role in implementing the technology in practice; although they do not represent the overall public, they are the decision makers in their own estates regarding forestry and forest regeneration. Secondly, the professionals related to the production of forest regeneration material and plants from forest species are in a key role when it comes to practically introducing the new technology to the forest owners. In this survey, perceptions of forest owners and professionals towards tree breeding and vegetative propagation were investigated. Additionally, the respondents were asked which traits they considered important to be improved by breeding, and their willingness to pay for these improved traits. The respondents valued the most: improved pest and pathogen resistance, improved resilience of forest in changing climate, and securing the species’ gene pool. Responses indicated that forest owners would be willing to pay more for the improved traits in forest regeneration material. The current novel study provides a foundation to concern public awareness regarding tree breeding and vegetative propagation in the future.

  • Tikkinen, Natural Resources Institute Finland ORCID https://orcid.org/0000-0002-2368-8042 E-mail: mikko.tikkinen@luke.fi (email)
  • Latvala, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: terhi.latvala@luke.fi
  • Aronen, Natural Resources Institute Finland (Luke), Production systems, Vipusenkuja 5, FI-57200 Savonlinna, Finland E-mail: tuija.aronen@luke.fi
article id 10369, category Research article
Tiina Laine, Ville Kankaanhuhta, Juho Rantala, Timo Saksa. (2020). Effects of spot mounding and inverting on growth of conifers, exposed mineral soil and natural birch regeneration. Silva Fennica vol. 54 no. 5 article id 10369. https://doi.org/10.14214/sf.10369
Keywords: boreal forest; regeneration; site preparation; mounding; young stand management
Highlights: There were 21% fewer naturally regenerated birches ha–1 in inverted areas (22 951) compared to spot mounded areas (29 086); Spot mounding exposed slightly, but not statistically significantly, larger area of mineral soil than inverting; There was no difference in seedling mortality or growth between the site preparation methods.
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In Nordic forests, consistent evidence about better seedling survival rate and increased growth due to site preparation have been obtained in numerous studies. Proper site preparation method can reduce costs of the whole regeneration chain through its effects on survival of planted seedlings, abundance of natural regeneration and competition in early stand development. This study compared the natural regeneration of birches (silver birch (Betula pendula Roth) and downy birch (B. pubescens Ehrh.)), amount of exposed mineral soil, and growth of planted seedlings between spot mounding and inverting site preparation methods. Present study was conducted in eight forest stands established in 2012 or 2015. Even though difference was not statistically significant, inverting exposed less mineral soil than spot mounding and thus reduced the natural regeneration of birch seedlings by 6135 seedlings ha–1 compared to spot mounding. However, the variation between regeneration areas was remarkable. There was no difference in seedling mortality or growth between the site preparation methods. In order to achieve high growth of conifers, moderate amount of exposed mineral soil and thus less naturally regenerated birch, inverting should be favored over spot mounding.

  • Laine, Metsä Group, P.O. Box 208, FI-70101 Kuopio, Finland E-mail: tiina.laine@metsagroup.com (email)
  • Kankaanhuhta, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: ville.kankaanhuhta@luke.fi
  • Rantala, Metsä Group, P.O. Box 10, FI-02020 METSÄ, Finland E-mail: juho.rantala@metsagroup.com
  • Saksa, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@luke.fi
article id 10370, category Research article
Juha Lappi, Timo Pukkala. (2020). Analyzing ingrowth using zero-inflated negative binomial models. Silva Fennica vol. 54 no. 4 article id 10370. https://doi.org/10.14214/sf.10370
Keywords: regeneration; continuous cover forestry; count data; generalized linear model; overdispersion; right-censoring
Highlights: Models were developed to describe ingrowth in national forest inventory data; The data were more dispersed than Poisson data and included many zeros; Fixed-effects models had larger zero-inflation probability and overdispersion parameter than mixed-effect models; Mixed-effects models had larger likelihood than fixed-effects models but provided biased predictions; Prediction of right-censored ingrowth may be useful owing to large overdispersion.
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Ingrowth is an important element of stand dynamics in several silvicultural systems, especially in continuous cover forestry. Earlier predictive models for ingrowth in Finnish forests are few and not based on up-to-date statistical methods. Ingrowth is here defined as the number of trees over 1.3 m entering a plot. This study developed new ingrowth models for Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.) and birch (Betula pendula Roth and B. pubescens Ehrh.) using data from the permanent sample plots of the Finnish national forest inventory. The data were over-dispersed compared to a Poisson process and had many zeros. Therefore, a zero-inflated negative binomial model was used. The total and species-specific stand basal areas, temperature sum and fertility class were used as predictors in the ingrowth models. Both fixed-effects and mixed-effects models were fitted. The mixed-effects model versions included random plot effects. The mixed-effects models had larger likelihoods but provided biased predictions. Also censored prediction was considered where only a certain maximum number of ingrowth trees were accepted for a plot. The models predicted most pine ingrowth in pine-dominated stands on sub-xeric and xeric sites where stand basal area was low. The predicted amount of spruce ingrowth was maximized when the basal area of spruce was 13 m2 ha–1. Increasing temperature sum increased spruce ingrowth. Predicted birch ingrowth decreased with increasing stand basal area and towards low fertility classes. An admixture of pine increased the predicted amount of spruce ingrowth.

  • Lappi, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: juha.lappi.sjk@gmail.com (email)
  • Pukkala, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: timo.pukkala@uef.fi
article id 10220, category Research article
Arnis Gailis, Pauls Zeltiņš, Andis Purviņš, Juris Augustovs, Valts Vīndedzis, Inga Zariņa, Āris Jansons. (2020). Genetic parameters of growth and quality traits in open-pollinated silver birch progeny tests. Silva Fennica vol. 54 no. 2 article id 10220. https://doi.org/10.14214/sf.10220
Keywords: Betula pendula; tree breeding; genetic gain; genetic parameters
Highlights: Growth and stem quality traits were under strong genetic control; Weak genetic correlations between tree growth and stem quality were found; Strong age-age and type-B correlations suggest robust improvement over time and different environments; Simultaneous improvement of growth and stem quality might be applicable.
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Genetic parameters of growth and stem quality traits were estimated for open-pollinated silver birch Betula pendula Roth progenies in Latvia at the age of 10 and 14 years. Tree height and stem volume were found to be under strong genetic control at both inventories (narrow-sense heritabilities varied from 0.41 to 0.66). Mainly low heritabilities were found for stem defects, yet genetic control of branch diameter, stem straightness and overall stem quality varied from low to high depending on study site. High additive genetic coefficient of variation was found for stem volume (25.3–32.5%). Genetic correlations among growth traits were strong and positive (0.90–0.99). Mainly weak genetic correlations between growth and quality traits implied simultaneous improvement. Still, strong negative correlations between branch angle and stem straightness might result in enlarged knot size for straighter logs. The genetic age-age correlations were strong. Weak genotype by environment interaction and stability of best genotypes over different sites was indicated by strong genetic correlations between trials. Each growth or quality trait alone showed substantial improvement in terms of estimated genetic gain (up to 62% over trial mean for stem volume). Therefore, selection index combining both growth and stem quality may be developed.

  • Gailis, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: arnis.gailis@silava.lv
  • Zeltiņš, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia ORCID https://orcid.org/0000-0002-6286-5814 E-mail: pauls.zeltins@silava.lv (email)
  • Purviņš, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: andis.purvins@silava.lv
  • Augustovs, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: juris.augustovs@silava.lv
  • Vīndedzis, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: valts.vindedzis@silava.lv
  • Zariņa, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: inga.zarina@silava.lv
  • Jansons, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: aris.jansons@silava.lv
article id 10243, category Research article
Laura Pikkarainen, Jaana Luoranen, Antti Kilpeläinen, Teppo Oijala, Heli Peltola. (2020). Comparison of planting success in one-year-old spring, summer and autumn plantings of Norway spruce and Scots pine under boreal conditions. Silva Fennica vol. 54 no. 1 article id 10243. https://doi.org/10.14214/sf.10243
Keywords: Pinus sylvestris; Picea abies; seedling damage; forest regeneration; field performance; planting season
Highlights: In Norway spruce, 84% of all plantings were successful, whereas in Scots pine, the corresponding number was 52%; The major reason for poor planting results was poor work quality; An extended planting season is possible for Norway spruce in southern and central Finland; In Scots pine, there are still large uncertainties in the success of summer and autumn plantings.
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In Nordic countries, tree planting of seedlings is mainly performed during spring and early summer. Interest has increased in extending the planting window throughout the unfrozen growing season. This study compared the success of one-year-old spring, summer and autumn plantings in practical forestry in Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in southern and central Finland. Planting success was based on the number of viable seedlings per hectare relative to a species-specific target density. The influence of different factors to poor planting results were determined, including quality of site preparation and planting, and sources of natural damage. Overall, in Norway spruce, 85, 69 and 84% and in Scots pine 53, 55 and 40% of spring, summer and autumn plantings succeeded. In Norway spruce, the planting results were consistent between the southern and central regions, whereas in Scots pine, the success was slightly lower in the south. The poor work quality and a low density of appropriate planting spots, contributed to poor planting results, regardless of planting season, region or tree species. Considering different damages, especially mammal damage contributed to the failure of Scots pine spring plantings, whereas in summer plantings, corresponding single failure reason could not be identified. Based on our findings, extending the planting season of Norway spruce could be recommended in both regions. For Scots pine, there is still significant uncertainty about the success of summer and autumn plantings, partially due to the limited number of plantings available for analyses.

  • Pikkarainen, School of Forest Sciences, University of Eastern Finland, Yliopistonkatu 7, FI-80100 Joensuu, Finland E-mail: laura.pikkarainen@uef.fi (email)
  • Luoranen, Natural Resources Institute Finland (Luke), Production Systems, Neulaniementie 5, FI-70210 Kuopio, Finland E-mail: jaana.luoranen@luke.fi
  • Kilpeläinen, School of Forest Sciences, University of Eastern Finland, Yliopistonkatu 7, FI-80100 Joensuu, Finland E-mail: antti.kilpelainen@uef.fi
  • Oijala, Metsä Group, Metsä Forest, Kuormaajantie 7, FI-40320 Jyväskylä, Finland E-mail: teppo.oijala@metsagroup.com
  • Peltola, School of Forest Sciences, University of Eastern Finland, Yliopistonkatu 7, FI-80100 Joensuu, Finland E-mail: heli.peltola@uef.fi
article id 10019, category Research article
Junyan Liu, Junfeng Tang, Si-Chong Chen, Wenbao Ma, Zheng Zheng, Tingfa Dong. (2019). Do tree cavity density and characteristics vary across topographical habitats in the tropics? A case study from Xishuangbanna, southwest China. Silva Fennica vol. 53 no. 1 article id 10019. https://doi.org/10.14214/sf.10019
Keywords: heterogeneity; cavity-dependant animals; tropical rainforest; biodiversity conservation
Highlights: Cavities were significantly more abundant in high- and low-slope than high-plateau habitats; There are more “butt hollow” cavities in high-slope habitat and they occurred at a lower height; More “crack” cavities in low-slope habitat and they had a narrower entrance diameter; Certain types of cavities are concentrated in specific habitats, which provide opportunities for forest management and biodiversity conservation.
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Despite the influence of cavities on the survival and distribution of cavity-dependent fauna, the variation in the density and characteristics of tree cavities across different habitat types in tropical forests is unknown. In this study, we surveyed 26 312 living trees from 376 species and compared cavity density and characteristics (height, size, type, and orientation) across five habitat types (valley, low-slope, high-slope, high-gully, and high-plateau) in a 20-hectare tropical rainforest in southwest China. From a total of 2047 cavities, we found that cavity density was mainly driven by habitat rather than tree species richness or diameter at breast height (DBH), and the characteristics of cavities were not uniformly distributed across habitats. Cavities were significantly more abundant in high- and low-slope than high-plateau habitats. Compared with other habitats, more “butt hollow” cavity types were found in high-slope habitat and they occurred at a lower tree height, whereas more “crack” cavities were found in low-slope habitat and they had a narrower entrance diameter. Although the mean orientation of cavities faced towards the northeast, cavity orientation varied significantly across habitat types. Our results indicate that certain types of cavities are concentrated in specific habitat types, which can provide avenues for forest management and biodiversity conservation. We highlight the importance of habitat heterogeneity in providing resources for cavity nesters.

  • Liu, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China; Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China E-mail: liujunyan2300@163.com
  • Tang, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China E-mail: jft@nn.ch
  • Chen, Royal Botanic Gardens, Kew, Wakehurst Place, West Sussex RH17 6TN, UK; Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Beer-Sheva 8499000, Israel E-mail: chensichong0528@gmail.com
  • Ma, Ecological Restoration and Conservation of Forests and Wetlands Key Laboratory of Sichuan Province, Sichuan Academy of Forestry, Chengdu 610081, China E-mail: mawenbao_2000@126.com
  • Zheng, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China E-mail: dioeco@outlook.com
  • Dong, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China E-mail: dongtf@aliyun.com (email)
article id 10036, category Research article
Karin Hjelm, Lars Rytter. (2018). The demand of hybrid aspen (Populus tremula × P. tremuloides) on site conditions for a successful establishment on forest land. Silva Fennica vol. 52 no. 5 article id 10036. https://doi.org/10.14214/sf.10036
Keywords: regeneration; site preparation; clone effects; poplars; soil acidity
Highlights: Low pH (below 3.5) reduced growth, but not survival, in a greenhouse study; Site preparation methods did not affect survival in field, but differences were found for growth; Mounding had generally the best effect on growth; Clonal differences were found that could be useful for improving establishment and growth.
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Hybrid aspen (Populus tremula L. × P. tremuloides Michx.) is a deciduous tree species suitable for producing large amounts of renewable biomass during short rotations. Its potential under North European conditions could be largely extended if not only agricultural land but also forest land was used for cultivation. Unfortunately, the knowledge of appropriate forest site conditions and effects of site preparation methods on hybrid aspen establishment is limited. In this paper, two studies that explore these questions are presented. In the first study, the sensitivity to acid soils was tested under greenhouse conditions in two type of soils: a) peat soil limed to certain pH levels (3.4–5.7) and b) collected forest soils where pH varied from 3.9 to 5.3. The lowest pH level resulted in reduced growth, elsewhere no significant differences were found. The second study was applied in the field and investigated the effect of four site preparation methods on survival and growth. The methods were: 1) control with no site preparation, 2) patch scarification, 3) mounding and 4) soil inversion. While no differences were found for survival, mounding was generally the method with the highest growth and patch scarification was least successful. The result was probably an effect of good soil aeration and less competition from vegetation after mounding. The field study also revealed clonal differences in growth performance, which stresses the importance of clone selection prior to planting. The results of these studies indicate that hybrid aspen is less sensitive to variation in pH and site preparation methods compared with other poplar species, as have been found in similar studies.

  • Hjelm, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden E-mail: karin.hjelm@skogforsk.se (email)
  • Rytter, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden ORCID http://orcid.org/0000-0001-6183-4832 E-mail: lars.rytter@skogforsk.se
article id 10000, category Research article
Hamed Yousefzadeh, Rasta Rajaei, Anna Jasińska, Łukasz Walas, Yann Fragnière, Gregor Kozlowski. (2018). Genetic diversity and differentiation of the riparian relict tree Pterocarya fraxinifolia (Juglandaceae) along altitudinal gradients in the Hyrcanian forest (Iran). Silva Fennica vol. 52 no. 5 article id 10000. https://doi.org/10.14214/sf.10000
Keywords: plant variation; Caucasian wingnut; population genetics; refugium; riparian forest; river system
Highlights: The Caucasian wingnut (Pterocarya fraxinifolia Spach) is an emblematic and relict riparian tree with limited distribution in Hyrcanian forest which investigating its genetic population structure and diversity along altitudinal gradients, and migration patterns are novel; We concluded that rivers are the main seed dispersal vector among P. fraxinifolia populations and there was no trend from upstream to downstream; The high level of gene flow and uniform genetic diversity along each river system suggest the “classical” metapopulation structure of the species.
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Riparian trees, especially relict trees, are attractive and important for research to understand both past and recent biogeographical and evolutionary processes. Our work is the first study to elucidate the genetic diversity and spatial genetic structure of the canopy-dominating riparian Pterocarya fraxinifolia (Juglandaceae) along two altitudinal gradients in different river systems of the Hyrcanian forest, which is one of the most important refugium of relict trees in Western Eurasia. Altitudinal gradients were chosen along two river systems at 100, 400 and 900 m a.s.l. Leaf samples were collected from 116 trees, and the genetic diversity was evaluated with eight SSR markers. Overall, 39 alleles were identified for all of the populations studied. The observed heterozygosity (Ho) varied from 0.79 to 0.87 (with a mean of 0.83). The results of the AMOVA analysis indicated that the variation within populations was 88%, whereas the variation among populations was 12% for all of the gradients. A structure analysis indicated that 93% of the trees were grouped in the same gradient. The genetic distance based on Fst confirmed the structure result and indicated a high rate of gene flow among the investigated populations. Based on high gene flow (low differentiation of the population along the same river) and the clearly distinct genetic structure of the investigated gradients, it can be concluded that rivers are the main seed dispersal vector among P. fraxinifolia populations. The genetic diversity of P. fraxinifolia did not show any trend from upstream to downstream. The high level of gene flow and uniform genetic diversity along each river suggest the “classical” metapopulation structure of the species.

  • Yousefzadeh, Department of Environmental Science, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran E-mail: h.yousefzadeh@modares.ac.ir (email)
  • Rajaei, Department of Forestry, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran E-mail: r.rajaei@modares.ac.ir
  • Jasińska, Laboratory of Systematics and Geography, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, PL-62-035 Kornik, Poland E-mail: jasiak9@wp.pl
  • Walas, Laboratory of Systematics and Geography, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, PL-62-035 Kornik, Poland E-mail: lukaswalas@wp.pl
  • Fragnière, Department of Biology and Botanic Garden, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland E-mail: yann.fragniere@unifr.ch
  • Kozlowski, Department of Biology and Botanic Garden, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland; Natural History Museum Fribourg, Chemin du Musée 6, CH-1700 Fribourg, Switzerland E-mail: gregor.kozlowski@unifr.ch
article id 9987, category Research article
Monika Dering, Katarzyna Sękiewicz, Grzegorz Iszkuło, Aleksandra Chojnacka, Dominik Tomaszewski, Emilia Pers-Kamczyc, Piotr Karolewski. (2018). Spatial genetic structure and clonal structure of Prunus serotina during invasive spread. Silva Fennica vol. 52 no. 3 article id 9987. https://doi.org/10.14214/sf.9987
Keywords: genetic structure; invasiveness; black cherry; colonization; clonal structure
Highlights: The spread of Prunus serotina in invaded forests is facilitated by high propagule pressure; The seed shadow overlap prevents strong spatial genetic structure; During colonization of isolated site, a strong spatial genetic structure is produced due to founder effect; Overall clonality in P. serotina was low but may efficiently support seedling bank thus contributing to species invasiveness.
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Prunus serotina Ehrh. (black cherry) is one of the most important invaders in the European forests, but existing studies have given limited insight into demo-genetic factors underpinning the process of species invasion. Fine-scale genetic structure (FSGS) may deliver important knowledge on genetics of invasion contributing to efficient management of the alien species. Using eight microsatellites we investigated FSGS, clonal structure and relatedness in four black cherry populations which represented different stages of the invasive spread into Scots pine forests. Three populations were in a continuous forest complex and represented the colonization (Z_1) and established stages (Z_2 and Z_3). To investigate how colonization ability of the species is modified by landscape features, we analyzed an isolated population at colonization stage located in limited forest patch located in an agricultural landscape (R). Populations from continuous forest showed low yet significant positive FSGS with Sp = 0.0068 in Z_1, 0.0054 in Z_2, and 0.0066 in Z_3, while in R spatial structure was the strongest (0.0145). Considerable relatedness noted in population R suggests a dominance of within-population mating and recruitments, low immigration rate and limited seed dispersal, all of which led to the observed strong FSGS. Also, we presume that a founder effect likely involved during colonization of isolated forest patch R led to strong FSGS. In contrary, the seed shadow overlap in the populations from continuous forest prevented strong FSGS and facilitated colonization. Despite of low level of clonality, we argue that it may efficiently support black cherry seedling bank contributing to species invasiveness.

  • Dering, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: mdering@man.poznan.pl (email)
  • Sękiewicz, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: ksekiewicz@man.poznan.pl
  • Iszkuło, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland; Faculty of Biological Sciences, University of Zielona Góra, Prof. Z. Szafrana 1, 65-516 Zielona Góra, Poland E-mail: iszkulo@man.poznan.pl
  • Chojnacka, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: jagoda900@gmail.com
  • Tomaszewski, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: dominito@man.poznan.pl
  • Pers-Kamczyc, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: epk@man.poznan.pl
  • Karolewski, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: pkarolew@man.poznan.pl
article id 9946, category Research article
Frauke Fedderwitz, Niklas Björklund, Velemir Ninkovic, Göran Nordlander. (2018). Does the pine weevil (Hylobius abietis) prefer conifer seedlings over other main food sources? Silva Fennica vol. 52 no. 3 article id 9946. https://doi.org/10.14214/sf.9946
Keywords: Pinus sylvestris; Picea abies; forest regeneration; feeding preference; herbivore; plant tissues
Highlights: Adult pine weevils feed on seedlings and mature conifers, but cause economic damage only on seedlings; Their feeding preferences for branches and roots over seedlings were tested in a laboratory experiment; The only clear preference was for Norway spruce roots; Results support new approaches of seedling protection attempting to redirect pine weevils from planted seedlings to other food sources.
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Adult pine weevils (Hylobius abietis (L.)) feed on the tender bark of branches and roots of mature conifer trees and on the stem bark of conifer seedlings. Their feeding on mature trees does not cause any economic damage, but their feeding on planted seedlings is so devastating that the pine weevil is considered one of the most important forest pest insects in Europe. We asked whether the pine weevil prefers seedlings over other regularly utilized food sources. This question is of particular interest because new approaches to seedling protection are based on decreasing any preference for seedlings by using less palatable plants or by enhancing their defence (by genetic selection or by methyl jasmonate treatment). In a laboratory choice experiment we tested pine weevil feeding preferences for seedlings compared with branches and roots from mature trees (separately for Norway spruce and Scots pine). Pine weevils preferred roots, but not branches, of Norway spruce over seedlings of the same species. With Scots pine there were no clear preferences, but the weevils showed a tendency to prefer roots over seedlings. These results provide support for seedling protection approaches that attempt to redirect pine feeding from planted seedlings to other food sources.

  • Fedderwitz, Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-750 07 Uppsala, Sweden E-mail: frauke.fedderwitz@slu.se (email)
  • Björklund, Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-750 07 Uppsala, Sweden E-mail: niklas.bjorklund@slu.se
  • Ninkovic, Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-750 07 Uppsala, Sweden E-mail: velemir.ninkovic@slu.se
  • Nordlander, Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-750 07 Uppsala, Sweden E-mail: goran.nordlander@slu.se
article id 9933, category Research article
Timo Saksa, Jari Miina, Hilkka Haatainen, Kauko Kärkkäinen. (2018). Quality of spot mounding performed by continuously advancing mounders. Silva Fennica vol. 52 no. 2 article id 9933. https://doi.org/10.14214/sf.9933
Keywords: soil preparation; slash; logging residues; forest regeneration; mixed modelling
Highlights: The number and quality of mounds varied considerably according to the operating conditions;The main factors reducing the quality of spot mounding were steep terrain, a thick humus layer, fresh logging residues, stoniness and soil texture;With careful selection of timing and conditions for mounding, the quality obtained by continuously advancing mounders can be improved.
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Operating conditions affecting the quality of spot mounding by Bracke continuously advancing mounders were investigated on 66 regeneration areas (124 ha) in eastern Finland. The quality of mounds was classified as suitable (good or acceptable after additional compression) or unsuitable for planting. Models were constructed for the number of suitable planting spots obtained per hectare (good and acceptable mounds), the probability of successful mounding (≥1600 planting spots ha–1) and the probability of creating a suitable mound as a function of terrain, site and soil characteristics, as well as slash conditions (removed, fresh or dry logging residues). The average number of mounds created was 1892 ± 290 mounds ha–1, of which 1398 ± 325 mounds ha–1 (74%) were classified as suitable for planting. The quality of spot mounding was reduced by steep terrain, a thick humus layer and fresh logging residues. Stoniness and soil texture also affected the number of planting spots created. Mounding after logging residues had dried increased the number of planting spots by 191 spots ha–1 compared with mounding in the presence of fresh residues. Removing residues did not significantly increase the number of planting spots compared with mounding amongst dry residues. A thick humus layer, very stony soil, steep slopes and valley terrain decreased the number of planting spots by 150–450 spots ha–1. The number and quality of mounds varied considerably according to the operating conditions, but with careful selection of timing and sites the quality obtained by a continuously advancing mounder can be improved.

  • Saksa, Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@luke.fi (email)
  • Miina, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: jari.miina@luke.fi
  • Haatainen, Faculty of Science and Forestry, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hilkka.haatainen@storaenso.com
  • Kärkkäinen, Tornator Oyj, Muuntamontie 2, FI-80100 Joensuu, Finland E-mail: kauko.karkkainen@tornator.fi
article id 7738, category Research article
Samuel Egbäck, Bo Karlsson, Karl-Anders Högberg, Kenneth Nyström, Mateusz Liziniewicz, Urban Nilsson. (2018). Effects of phenotypic selection on height-diameter ratio of Norway spruce and Scots pine in Sweden. Silva Fennica vol. 52 no. 2 article id 7738. https://doi.org/10.14214/sf.7738
Keywords: Pinus sylvestris; Picea abies; genetic correlations; heritability; Genetic selection; slenderness
Highlights: Swedish plus-tree selection promoted less slender Norway spruce trees and more slender Scots pine trees compared to neighboring trees; Similar results were also found for progeny trials which indicated that genetics played a prominent role in phenotypic appearance.
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Genetically improved Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) are extensively used in operational Swedish forestry plantations. However, relatively little is known about the stem slenderness (height-diameter ratio) of genetically improved material. Thus, in this study we investigated effects of plus-tree selection on stem slenderness of Norway spruce and Scots pine in Sweden by evaluating both the plus-tree selection and a large number of progeny trials. Species-specific models for predicting the height-diameter ratio were estimated using regression and mixed model approach. Our results show that phenotypic plus-tree selection promoted less slender Norway spruce trees and more slender Scots pine trees compared to neighboring trees. Similar results were also found for the progeny trials which indicated that genetics played a prominent role in the phenotypic appearance. Compared to the progeny of neighboring trees, Norway spruce plus-tree progenies had a 5.3% lower height-diameter ratio, while Scots pine plus-tree progenies had a 1.5% greater height-diameter ratio. The narrow sense heritability for height-diameter ratio was 0.19 for Norway spruce and 0.11 for Scots pine, indicating that it is possible to modify the height-diameter ratio by breeding. Correlation coefficients between breeding values for height-diameter ratio and diameter were negative for Scots pine (–0.71) and Norway spruce (–0.85), indicating that selection for diameter only would result in less slender stems of both species. Similar correlations were also found between breeding values for height-diameter ratio and height of Scots pine (–0.34) and Norway spruce (–0.74).

  • Egbäck, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, 230 53 Alnarp, Sweden E-mail: samuel.egback@slu.se (email)
  • Karlsson, Skogforsk, Ekebo, 268 90 Svalöv, Sweden E-mail: bo.karlsson@skogforsk.se
  • Högberg, Skogforsk, Ekebo, 268 90 Svalöv, Sweden E-mail: karl-anders.hogberg@skogforsk.se
  • Nyström, Swedish University of Agricultural Sciences, Department of Forest Resource Management, Skogsmarksgränd, 901 83 Umeå, Sweden E-mail: kenneth.nystrom@slu.se
  • Liziniewicz, Skogforsk, Ekebo, 268 90 Svalöv, Sweden E-mail: Mateusz.Liziniewicz@skogforsk.se
  • Nilsson, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, 230 53 Alnarp, Sweden E-mail: urban.nilsson@slu.se
article id 1665, category Research article
Lauri Haataja, Ville Kankaanhuhta, Timo Saksa. (2018). Reliability of self-control method in the management of non-industrial private forests. Silva Fennica vol. 52 no. 1 article id 1665. https://doi.org/10.14214/sf.1665
Keywords: forest management; soil preparation; quality control; young stand management; forest regeneration; boreal silviculture; forest planting
Highlights: Self-control method was found reliable at the main stages of the forest regeneration process; Only slight overestimation was found in self-control results of soil preparation and planting and small underestimation in self-control of young stand management; Diverse utilizing of self-control data is possible in support of service providers operations.
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This study seeks to determine the extent to which self-control data can be relied upon in the management of private forests. Self-control (SC) requires the forest workers to evaluate their own work quality to ensure the clients’ needs are met in terms of soil preparation, planting and young stand management. Self-control data were compared to an independent evaluation of the same worksites. Each dataset had a hierarchical structure (e.g., sample plot, regeneration area and contractor), and key quality indicators (i.e., number of prepared mounds, planted seedlings or crop trees) were measured for each plot.  Self-control and independent-assessments (IA) were analyzed by fitting a multi-level multivariate model containing explanatory variables. No significant differences were observed in terms of soil preparation (number of mounds) or young stand management (number of crop trees) between self-control and independent-assessments. However, the self-control planting data included a slight but significant overestimation of the number of planted seedlings. Discrepancies are discussed in terms of sampling error and other explanatory factors. According to overall results, self-control methods are reliable at every stage of the forest regeneration process. As such, the diverse utilizing of self-control data is possible in support of service providers operations.
  • Haataja, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: lauritapiohaataja@gmail.com (email)
  • Kankaanhuhta, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: ville.kankaanhuhta@luke.fi
  • Saksa, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@luke.fi
article id 1760, category Research article
Marek Fajstavr, Kyriaki Giagli, Hanuš Vavrčík, Vladimír Gryc, Josef Urban. (2017). The effect of stem girdling on xylem and phloem formation in Scots pine. Silva Fennica vol. 51 no. 4 article id 1760. https://doi.org/10.14214/sf.1760
Keywords: Pinus sylvestris; radial increment; cambial activity; cell differentiation; phloemogenesis; xylogenesis
Highlights: Stem girdling ceased the cambial activity, below the girdled area, immediately after the removal of the bark strip; Pinus sylvestris survived for up to two years after stem girdling; The girdled trees formed phloem cells above the girdled area but failed to form latewood cells in the next growing season.
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Scots pine (Pinus sylvestris L.) is a resilient, wide spread species. This paper reports on the xylem and phloem cell formation process, before and after, the species was put under artificial stress by stem girdling. Microcore method was applied to a healthy control group and a standing group of girdled trees within an 80-year-old pine forest for two consecutive growing seasons (2013 and 2014). The stem girdling was applied in the middle of the first growing season (July 2013). Cambial activity timings (onset and cessation of cell division), cell formation intensity, cell differentiation, and the dynamics of the annual radial increment in the stem were analyzed. Cambial activity was inhibited and eventually ceased below the stem girdling immediately after the removal of the strip. Therefore, no latewood tracheids were formed. However, above the stem girdling and in the control trees, cell formation and tissue differentiation continued until the end of the growing season, with the girdled trees moving at a less intensive pace but for a longer period of time. During the following growing season (2014), the cambial zone was reactivated only above the stem girdling, not below, and eventually the girdled trees died. In 2014, the onset of the cambial activity was delayed and the division rate of the cells was slower in the girdled trees. Furthermore, the girdled trees formed less phloem cells than the control trees.

  • Fajstavr, Department of Wood Science, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, 613 00 Brno, Czech Republic E-mail: fajstavr.marek@seznam.cz (email)
  • Giagli, Department of Wood Science, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, 613 00 Brno, Czech Republic E-mail: kyriaki.giagli@mendelu.cz
  • Vavrčík, Department of Wood Science, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, 613 00 Brno, Czech Republic E-mail: vavrcik@mendelu.cz
  • Gryc, Department of Wood Science, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, 613 00 Brno, Czech Republic E-mail: gryc@mendelu.cz
  • Urban, Department of Forest Botany, Dendrology and Geobiocenology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, 613 00 Brno, Czech Republic;  Siberian Federal University, Svobodnyj Prospect 79, Krasnoyarsk, 660041 Krasnoyarsk, Russia E-mail: josef.urban@email.cz
article id 1691, category Research article
Enéas Ricardo Konzen, Raquel Peron, Márcio Akira Ito, Gilvano Ebling Brondani, Siu Mui Tsai. (2017). Molecular identification of bamboo genera and species based on RAPD-RFLP markers. Silva Fennica vol. 51 no. 4 article id 1691. https://doi.org/10.14214/sf.1691
Keywords: molecular markers; molecular screening; restriction enzymes; genetic divergence; Dendrocalamus; Bambusa
Highlights: We investigated the potential of RAPD-RFLP (Random Amplified Polymorphic DNA, Restriction Fragment Length Polymorphism) in detecting genetic relationships among bamboo genera and species; RFLP profiles resolved in acrylamide gels revealed high number of markers, which accurately differentiated species and genera, based on cophenetic correlation coefficients; We recommend RAPD-RFLP for analyses of genetic diversity and divergence among bamboo genera, species and varieties.
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Bamboo species have a very significant ecological and economic impact. Determining morphological and genetic differences among bamboo genera and species are crucial to explore desirable traits for breeding purposes. Several advances have been made in the taxonomy of bamboos by using molecular fingerprinting tools and next generation sequencing technologies. Nevertheless, classical molecular markers such as RAPD (Random Amplified Polymorphic DNA), AFLP (Amplified Fragment Length Polymorphism) and ISSR (Inter Simple Sequence Repeats) also provide an accurate discrimination among genera and species. Moreover, the RAPD-RFLP (Random Amplified Polymorphic DNA, Restriction Fragment Length Polymorphism) method, in which amplification products from RAPD are digested with restriction enzymes, is a reliable, fast and cost-effective method for fingerprinting. RAPD-RFLP has been scarcely used in the literature and no report regarding bamboo taxonomy is available with this method. Here we explored the molecular (RAPD, RAPD-RFLP) variation among genera (Bambusa, Dendrocalamus, Guadua and Phyllostachys) and species of bamboo cultivated in Brazil. Both molecular markers allowed clear distinction among the genera studied. Moreover, high cophenetic correlation values in UPGMA clusters indicated their potential for discriminating bamboo species. The digestion of RAPD products (RFLP) resulted in high number of polymorphic bands and produced very characteristic profiles for each genus with three enzyme combinations (HindIII/HaeIII, HinfI/RsaI, and single digestion with MspI). We recommend RAPD-RFLP as a reproducible and informative method for screening differences among genera, species and varieties of bamboos. Providing a cost-effective and accurate method for species identification and characterization is straightforward for bamboo conservation, management and breeding.

  • Konzen, Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture (CENA), University of Sao Paulo (USP), Centenário Av., 303, Piracicaba, SP, P.O. Box 96, Brazil; Forest Sciences, Federal University of Lavras (UFLA), Lavras, MG, P.O. Box 3037, Brazil E-mail: erkonzen@gmail.com (email)
  • Peron, Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture (CENA), University of Sao Paulo (USP), Centenário Av., 303, Piracicaba, SP, P.O. Box 96, Brazil E-mail: rperon@purdue.edu
  • Ito, Embrapa Western Agriculture, Brazilian Agricultural Research Corporation (EMBRAPA), BR 163 Rd., km 253, Dourados, MS, P.O. Box 449, Brazil E-mail: marcio.ito@embrapa.br
  • Brondani, Forest Sciences, Federal University of Lavras (UFLA), Lavras, MG, P.O. Box 3037, Brazil E-mail: gebrondani@gmail.com
  • Tsai, Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture (CENA), University of Sao Paulo (USP), Centenário Av., 303, Piracicaba, SP, P.O. Box 96, Brazil E-mail: tsai@cena.usp.br
article id 7001, category Research article
Fei-Fei Zhai, Jun-Xiang Liu, Zhen-Jian Li, Jin-Mei Mao, Yong-Qiang Qian, Lei Han, Zhen-Yuan Sun. (2017). Assessing genetic diversity and population structure of Salix viminalis across Ergun and West Liao basin. Silva Fennica vol. 51 no. 3 article id 7001. https://doi.org/10.14214/sf.7001
Keywords: genetic variation; microsatellites; geographic barrier; basket willow; common osier
Highlights: High genetic diversity and moderate population differentiation were detected in twelve Salix viminalis populations; Populations from Ergun basin presented higher genetic diversity than populations from West Liao basin; Populations with short distances presented low differentiation.
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Salix viminalis L. is an important shrub that has potential for use as a bioenergy crop, for phytoremediation of heavy metal contaminated soil and sewage sludge treatment. It is mainly distributed in the northeast of China, but the species has not yet been used a resource here. We examined the genetic diversity and population structure of populations from the Ergun basin and West Liao basin using 20 microsatellite markers. A high level of genetic diversity (Na = 16.45, He = 0.742) was detected for S. viminalis, and populations from the Ergun basin exhibited higher genetic diversity and private alleles numbers than the West Liao basin. The 12 populations could be divided into two clusters by both Bayesian analysis and UPGMA clustering which were consistent with the populations derived from the two basins. Moderate population differentiation (FST = 0.076) was shown in S. viminalis, and AMOVA analysis confirmed that most of the genetic variation (86.13%) was attributed to individual differences within populations, while 11.49% was attributed to differences between basins and 2.38% to differences within each basin. Significant correlations of FST/(1–FST) with log (geographic distance) among 12 populations (r = 0.634, p < 0.00) and 10 populations within the Ergun basin (r = 0.482, p = 0.0002) indicated that geographical distance was the principal factor influencing genetic structure. As most of genetic variation exist within populations, so protection measures should be focused on populations with higher genetic diversity and unique alleles, such as Tuli, Mordaga downstream, Zhadun1 and Genhe.

  • Zhai, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China; School of Architectural and Artistic Design, Henan Polytechnic University, Century Avenue, Jiaozuo, Henan, 454000, PR China E-mail: lkyzff@163.com
  • Liu, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: liu-jx295@163.com
  • Li, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: zhenjianli@163.com
  • Mao, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China; Research Institute of Economic Forest, Xinjiang Academy of Forestry, Anjunanlu, Urumqi, Xinjiang, PR China E-mail: 350512173@qq.com
  • Qian, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: qianyq@caf.ac.cn
  • Han, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: hdd@caf.ac.cn
  • Sun, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: lkyszy@126.com (email)
article id 5662, category Research article
Samuel Egbäck, Urban Nilsson, Kenneth Nyström, Karl-Anders Högberg, Nils Fahlvik. (2017). Modeling early height growth in trials of genetically improved Norway spruce and Scots pine in southern Sweden. Silva Fennica vol. 51 no. 3 article id 5662. https://doi.org/10.14214/sf.5662
Keywords: Pinus sylvestris; Picea abies; individual tree growth model; genetic component; genetic multiplier; unimproved material; improved material
Highlights: The developed height growth model based on unimproved material predicted the development relatively well for genetically improved Norway spruce; For genetically improved Scots pine, however, the model needed to be modified; By incorporating a genetic component into the Scots pine model, the prediction errors were reduced.
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Genetically improved Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) are used extensively in operational Swedish forestry plantations to increase production. Depending on the genetic status of the plant material, the current estimated genetic gain in growth is in the range 10–20% for these species and this is expected to increase further in the near future. However, growth models derived solely from data relating to genetically improved material in Sweden are still lacking. In this study we investigated whether an individual tree growth model based on data from unimproved material could be used to predict the height increment in young trials of genetically improved Norway spruce and Scots pine. Data from 11 genetic experiments with large genetic variation, ranging from offspring of plus-trees selected in the late 1940s to highly improved clonal materials selected from well performing provenances were used. The data set included initial heights at the age of 7–15 years and 5-year increments for almost 2000 genetic entries and more than 20 000 trees. The evaluation indicated that the model based on unimproved trees predicted height development relatively well for genetically improved Norway spruce and there was no need to incorporate a genetic component. However, for Scots pine, the model needed to be modified. A genetic component was developed based on the genetic difference recorded within each trial, using mixed linear models and methods from quantitative genetics. By incorporating the genetic component, the prediction errors were significantly reduced for Scots pine. This study provides the first step to incorporate genetic gains into Swedish growth models and forest management planning systems.

  • Egbäck, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, 230 53 Alnarp, Sweden E-mail: samuel.egback@slu.se (email)
  • Nilsson, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, 230 53 Alnarp, Sweden E-mail: urban.nilsson@slu.se
  • Nyström, Swedish University of Agricultural Sciences, Department of Forest Resource Management, Skogsmarksgränd, 901 83 Umeå, Sweden E-mail: kenneth.nystrom@slu.se
  • Högberg, Skogforsk, Ekebo, 268 90 Svalöv, Sweden E-mail: karl-anders.hogberg@skogforsk.se
  • Fahlvik, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, 230 53 Alnarp, Sweden E-mail: nils.fahlvik@slu.se
article id 1743, category Research article
Gintare Sabalinkiene, Darius Danusevicius, Michael Manton, Gediminas Brazaitis, Kastytis Simkevicius. (2017). Differentiation of European roe deer populations and ecotypes in Lithuania based on DNA markers, cranium and antler morphometry. Silva Fennica vol. 51 no. 3 article id 1743. https://doi.org/10.14214/sf.1743
Keywords: genetic structure; inbreeding; Capreolus capreolus; polymorphism; wild game management
Highlights: Lithuanian roe deer populations are genetically structured into southern and northern groups, most likely affected by a divergent gene flow and Lithuania’s largest rivers slowing down migration; Microsatellite and skull morphology based genetic differentiation between field and forest ecotypes are weak; Geographical location has a significant effect on antler morphometry traits and skull size of male roe deer, the latter increasing northwards.
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The objective of our study was to assess the genetic and morphological differentiation of European roe deer (Capreolus capreolus L.) in Lithuania based on DNA markers, skull and anther morphology. DNA was extracted from 79 culled individuals at 13 locations and genotyped at five nuclear microsatellite loci. Based on culling location, individuals were assigned to either a field (N = 43) or a forest ecotype (N = 36). Skull and antler morphometry was studied on 603 and 292 individuals, respectively. Results showed no significant genetic and skull morphology differentiation between the ecotypes. The forest ecotype tends to exhibit lower genetic diversity compared to the field ecotype, particularly for male individuals. The genetic differentiation of roe deer in Lithuania was significant based on the RST values, but not on the FST values. A STRUCTURE analyses revealed southern and northern genetic clusters, most likely affected by divergent gene flow. The country’s major rivers Nemunas and Neris are likely to increase differentiation between the clusters. ANOVA on skull morphology by gender and age indicated a significant effect of geographical location. Skull size (especially length) is greater in the northern part of the country. We also found significant effects of age, ecotype and geographical location on most of the roe deer male antler morphometric traits.

  • Sabalinkiene, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania E-mail: gintare.sabalinkiene@asu.lt (email)
  • Danusevicius, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania E-mail: darius.danusevicius@asu.lt
  • Manton, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania E-mail: michael.manton@asu.lt
  • Brazaitis, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania E-mail: gediminas.brazaitis@asu.lt
  • Simkevicius, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania E-mail: kastytis.simkevicius@asu.lt
article id 1563, category Research article
Kristina Ahnlund Ulvcrona, Dan Bergström, Urban Bergsten. (2017). Stand structure after thinning in 1–2 m wide corridors in young dense stands. Silva Fennica vol. 51 no. 3 article id 1563. https://doi.org/10.14214/sf.1563
Keywords: heterogeneity; conventional thinning; future crop trees; production
Highlights: Boom corridor thinning (BCT) results in more stand structure heterogeneity than conventional thinning or pre-commercial thinning (PCT), maintaining both smaller-diameter trees and deciduous species; Neither dominant height nor number of possible future crop trees is jeopardized, and boom corridor thinning results in higher values of stem volume and biomass; The technique is flexible as various corridor types give similar stand structure results.
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Boom corridor thinning (BCT) has been proposed as a cost-effective technique for biomass thinning (BT) in young dense stands. The objective of this study was to determine how various BCT operations affect stand structure following biomass thinning and to compare the results with conventional selective thinning methods. Two series of field experiments were established; BCT 1-series: Three sites in south of Sweden (9 and 11 m in mean and dominating tree height) with five treatments, including a control, conventional selective thinning and three BCT treatments (1 m and 2 m wide corridors and selective BCT). The second BCT series: Three regions in Sweden (in the north, centre and in the south), with two stand sites in each region with different tree heights (4/9 m and 5/10 m in mean/dominating tree height). Treatments were control, pre-commercial thinning (PCT), conventional selective thinning and BCT (high and low thinning). Following the first biomass thinning, BCT regimes and selective thinning methods resulted in similar stand structures based on the number of possible future crop trees (>80 mm in diameter at breast height). However, BCT maintained a higher diversity of tree sizes as well as more stems per hectare, including deciduous species, than the selective thinning approaches. The stands after BCT should have more vertical complexity, especially when compared to pre-commercial thinning. The structural heterogeneity resulting from BCT may also increase stand biodiversity and ecosystem service values.

  • Ahnlund Ulvcrona, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: kristina.ulvcrona@slu.se (email)
  • Bergström, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: dan.bergstrom@slu.se
  • Bergsten, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: urban.bergsten@slu.se
article id 1721, category Research article
Anna Hebda, Błażej Wójkiewicz, Witold Wachowiak. (2017). Genetic characteristics of Scots pine in Poland and reference populations based on nuclear and chloroplast microsatellite markers. Silva Fennica vol. 51 no. 2 article id 1721. https://doi.org/10.14214/sf.1721
Keywords: Pinus sylvestris; phylogeography; conifers; genetic divergence; population structure; microsatellite markers; neutral variation
Highlights: Similar genetic variation was found between Polish Scots pine populations from a wide variety of habitats based on nSSR and cpSSR markers; Homogeneity was observed in the genetic structures of Polish and Finnish populations from the continuous pine range; Genetic differentiation in microsatellite markers was identified only when populations from the central pine distribution were compared to the marginal stands.
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Polymorphisms at a set of eighteen nuclear (nSSR) and chloroplast (cpSSR) microsatellite loci were investigated in sixteen populations of Scots pine (Pinus sylvestris L.) derived from the provenance trial experiment and representative of the species distribution range and climatic zones in Poland. The patterns of genetic variation were compared to the reference samples from the species distribution in Europe and Asia. A similar level of genetic variation and no evidence of population structure was found among the Polish stands. They showed genetic similarity and homogenous patterns of allelic frequency spectra compared to the Northern European populations. Those populations were genetically divergent compared to the marginal populations from Turkey, Spain and Scotland. The population structure patterns reflect the phylogeography of the species and the divergence of populations that most likely do not share recent history. As the analysed provenance trial populations from Poland are diverged in phenotypic traits but are genetically similar, they could be used to test for selection at genomic regions that influence variation in quantitative traits.

  • Hebda, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Ecology and Silviculture, Department of Genetics and Forest Tree Breeding, 29 Listopada 46, 31-425 Kraków, Poland ORCID http://orcid.org/0000-0002-3149-8644 E-mail: ana.hebda@gmail.com (email)
  • Wójkiewicz, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: bwojkiew@man.poznan.pl
  • Wachowiak, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland; Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland E-mail: witoldw@man.poznan.pl
article id 1678, category Research article
Juan F. Jimenez, Pedro Sánchez-Gómez, Jose Luis Cánovas, Isabell Hensen, Miloud Aouissat. (2017). Influence of natural habitat fragmentation on the genetic structure of Canarian populations of Juniperus turbinata. Silva Fennica vol. 51 no. 2 article id 1678. https://doi.org/10.14214/sf.1678
Keywords: genetic diversity; AFLP markers; Canarian juniper; oceanic islands
Highlights: Canarian populations of Juniperus turbinata exhibited levels of genetic diversity similar to those of mainland populations; Despite the historical geologic events occurred in Canary Islands, and the documented decrease of populations since the arrival of settlers, no genetic differentiation between islands has been observed; As it has been observed for other Macaronesian endemics, J. turbinata long dispersal ability seems to be the main force driving the genetic structure of populations.
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Oceanic archipelagos provide an important platform from which to evaluate the effects of isolation and fragmentation on the genetic structure of species. As a result of oceanic isolation, such species usually show lower levels of genetic diversity and higher genetic differentiation than their mainland congeners. However, this is not necessarily the case for long distance dispersal species, whose genetic structure is not strictly defined by population isolation. We assessed the level and distribution of genetic diversity among Canarian populations of Juniperus turbinata in order to evaluate the influence of population isolation on its genetic structure. Using Amplified Fragment Length Polymorphism markers, we analyzed molecular diversity among 175 individuals from five populations occurring across the Canary Island and three Moroccan populations. Principal Coordinate Analysis, neighbor joining clustering, AMOVA and Bayesian-based analysis were applied to examine population structure. Despite the documented habitat loss and decline in Canarian populations, Amplified Fragment Length Polymorphism markers revealed levels of intra-population genetic diversity that were similar to those from mainland populations, and low levels of genetic differentiation. Bayesian analysis of population structure showed three main clusters, one comprising El Hierro population and a few individuals from several islands, a second cluster that grouped the remaining Canarian populations together, and a third cluster grouping Moroccan populations. Our results suggest that the main force driving the genetic structure of Canarian populations of J. turbinata is its capacity for long distance dispersal.

  • Jimenez, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain E-mail: fjimenez@um.es (email)
  • Sánchez-Gómez, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain ORCID http://orcid.org/0000-0001-6754-1512 E-mail: psgomez@um.es
  • Cánovas, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain E-mail: joseluis.canovas@um.es
  • Hensen,  Institut für Biologie, Martin-Luther Universitat, 06099 Halle, Germany E-mail: isabell.hensen@botanik.uni-halle.de
  • Aouissat, Centre Universitaire Salhi Ahmed Naama, BP 66, Naâma, Algérie E-mail: aouissatm@yahoo.fr
article id 1566, category Research article
Valdir Marcos Stefenon, Jordana Caroline Nagel, Igor Poletto. (2016). Evidences of genetic bottleneck and fitness decline in Luehea divaricata populations from southern Brazil. Silva Fennica vol. 50 no. 5 article id 1566. https://doi.org/10.14214/sf.1566
Keywords: demographic history; effective population size; genetic resources conservation; Pampa biome
Highlights: Signatures of genetic bottlenecks and reduction of populations’ fitness were observed in populations of Luehea divaricata in southern Brazil; Lower levels of observed heterozygosity are correlated with populations’ fitness, decreasing germination capacity and increasing the proportion of anomalous germinated plantlets; Promoting the connection among populations is proposed as a key strategy towards conservation of L. divaricata genetic resources in its southernmost distribution range.
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Extant populations growing in regions that were refugia during the last glacial period are expected to show higher genetic diversity than populations that moved from these refugia into new areas in higher latitudes. Such new populations likely faced harsher climatic conditions, being established with reduced population size and experiencing the effects of genetic bottlenecks. In this study we employed data from nuclear SSR markers for detecting molecular signatures of genetic bottlenecks, and germination experiments to evaluate reduction of populations’ fitness in natural populations of Luehea divaricata Mart. et Zucc., growing in the southern range of the species distribution (around 30°S latitude). Signatures of genetic bottlenecks and reduction of populations’ fitness were observed in all populations. Lower levels of observed heterozygosity are correlated with populations’ fitness, decreasing germination capacity and increasing the proportion of anomalous germinated plantlets. Promoting the connection among populations is proposed as a key strategy towards conservation of L. divaricata genetic resources in its southernmost distribution range. The offspring from crosses among populations would significantly increase the observed heterozygosity and fitness of multiple populations.

  • Stefenon, Nucleus of Genomics and Molecular Ecology, Interdisciplinary Center of Biotechnological Research, Universidade Federal do Pampa, BR290 km, 97300-000, São Gabriel, RS, Brazil E-mail: valdirstefenon@unipampa.edu.br (email)
  • Nagel, Nucleus of Genomics and Molecular Ecology, Interdisciplinary Center of Biotechnological Research, Universidade Federal do Pampa, BR290 km, 97300-000, São Gabriel, RS, Brazil E-mail: jordana.nagel@yahoo.com.br
  • Poletto, Laboratory of Plant Protection, Universidade Federal do Pampa, BR290 km, 97300-000, São Gabriel, RS, Brazil E-mail: igorpoletto@unipampa.edu.br
article id 1682, category Research article
Jiří Korecký, Yousry A. El-Kassaby. (2016). Pollination dynamics variation in a Douglas-fir seed orchard as revealed by microsatellite analysis. Silva Fennica vol. 50 no. 4 article id 1682. https://doi.org/10.14214/sf.1682
Keywords: selfing; Pseudotsuga menziesii (Mirb.) Franco; genetic quality; pedigree reconstruction; gametic contribution; pollen contamination
Highlights: Important characteristics such as parental reproductive success, pollen contamination, and selfing rate in the second generation Douglas-fir seed orchard have been estimated; Since this research is a part of a multi-year study, outputs were compared to those from two other years; Results are in line and differences in pollination dynamics across years are attributable to the various crop management practices.
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As part of a multi-year monitoring study of pollination dynamics in a second generation Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed orchard, we estimated with the aid of eight microsatellite markers three important reproductive biology characteristics affecting the genetic worth and diversity of seed crops; namely parental reproductive success, pollen contamination, and selfing rate. The obtained results were compared to those from two previous years to gauge appropriate seed crop management practices and ultimately allow approximate generalization of seed crop genetic quality. We determined that 80% of parental gametes were produced by 52% of the parents, 13% of paternal gametes resulted from pollen contamination (i.e., gene flow), and 12% of the seed were the product of selfing. The obtained results were in line with those observed for 2005 and 2009 where 80% of gametes being produced by 37–48% of the parents, 10–18% pollen contamination, and 15–17% selfing rate. The observed reproductive biology parameters differences are attributable to the various crop management practices implemented (i.e., bloom delay and supplemental-mass-pollination) across years and calls for justification due to the observed minimal differences on seed crops genetic quality.

  • Korecký, Department of Genetics and Physiology of Forest Trees, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Praha 6, 165 21, Czech Republic ORCID http://orcid.org/0000-0001-7859-1750 E-mail: korecky@fld.czu.cz (email)
  • El-Kassaby, Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada ORCID http://orcid.org/0000-0002-4887-8977 E-mail: y.el-kassaby@ubc.ca
article id 1564, category Research article
Stanislav Vacek, Zdeněk Vacek, Lukáš Bílek, Jaroslav Simon, Jiří Remeš, Iva Hůnová, Jan Král, Tereza Putalová, Miroslav Mikeska. (2016). Structure, regeneration and growth of Scots pine (Pinus sylvestris L.) stands with respect to changing climate and environmental pollution. Silva Fennica vol. 50 no. 4 article id 1564. https://doi.org/10.14214/sf.1564
Keywords: Pinus sylvestris; natural regeneration; climate; stand development; production; air-pollution
Highlights: Pine forest stands showed positive development of stand structural characteristics related to their diversity, number of regeneration individuals and growth characteristics; Tree-ring width was positively correlated with precipitation, while it was negatively correlated with temperature in growing seasons; Mean NOx concentrations showed positive effect on radial growth of pine; Serious defoliation was caused by SO2 concentrations and N deposition in combination with extreme climate events.
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Changes in the structure and development of managed Scots pine (Pinus sylvestris L.) stands with respect to changing environmental conditions were set for the period 1979–2015. The study was conducted in conditions of natural pinewoods and pine-oak sites on five permanent research plots (0.25 ha) in Eastern Bohemia, Czech Republic (CR). Studied forest stands showed positive development of stand structural characteristics related to their diversity, number of regeneration individuals and growth characteristics. The standing volume of regularly distributed tree layer in 2015 was in the range of 320–434 m3 ha–1, which indicates an increase by 5.9–20.0% over 10 years. Correlation between pine radial increment and the amount of precipitation was generally the strongest one. Positive statistically significant correlation between diameter increment and temperature was demonstrated only for the average March temperature of the current year. Within the CR, study site can be characterised as a medium polluted area both for sulphur and nitrogen, despite this SO2 concentrations and N deposition in combination with extreme climate events caused severe defoliation in pine stands. Conversely, radial growth was positively significantly correlated with mean NOx concentrations. Drought mainly in combination with even medium environmental pollution can further worsen the health status of pine stands in lowland areas of Central Europe. Thus, formulation of silvicultural techniques able to mitigate the impact of these stress factors is needed.

  • Vacek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: vacekstanislav@fld.czu.cz
  • Vacek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: vacekz@fld.czu.cz
  • Bílek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: bilek@fld.czu.cz
  • Simon, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 3, 613 00 Brno, Czech Republic E-mail: jaroslav.simon@mendelu.cz
  • Remeš, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: remesj@email.cz (email)
  • Hůnová, Czech Hydrometeorological Institute, Na Šabatce 17 143 06 Prague, Czech Republic E-mail: hunova@chmi.cz
  • Král, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: kraljan@fld.czu.cz
  • Putalová, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: putalova@fld.czu.cz
  • Mikeska, University of Hradec Králové, Faculty of Science, Rokitanského 62, 500 03 Hradec Králové, Czech Republic E-mail: Mikeska.Miroslav@uhul.cz
article id 1562, category Research article
Mats Erik Berlin, Torgny Persson, Gunnar Jansson, Matti Haapanen, Seppo Ruotsalainen, Lars Bärring, Bengt Andersson Gull. (2016). Scots pine transfer effect models for growth and survival in Sweden and Finland. Silva Fennica vol. 50 no. 3 article id 1562. https://doi.org/10.14214/sf.1562
Keywords: Pinus sylvestris; adaptation; tree breeding; reaction patterns; forest regeneration material
Highlights: Scots pine transfer effect models for growth and survival, valid in both Sweden and Finland have been developed; The models use high-resolution gridded climate data and can predict performance in future climatic conditions; The models perform well both for unimproved and genetically improved material and can be used to develop deployment recommendations of contemporary forest regeneration material in Sweden and Finland.
Abstract | Full text in HTML | Full text in PDF | Author Info

In this study, we developed models of transfer effects for growth and survival of Scots pine (Pinus sylvestris L.) in Sweden and Finland using a general linear mixed-model approach. For model development, we used 378 provenance and progeny trials with a total of 276 unimproved genetic entries (provenances and stand seed check-lots) distributed over a wide variety of climatic conditions in both countries. In addition, we used 119 progeny trials with 3921 selected genetic entries (open- and control pollinated plus-tree families) for testing model performance. As explanatory variables, both climatic indices derived from high-resolution gridded climate datasets and geographical variables were used. For transfer, latitude (photoperiod) and, for describing the site, temperature sum were found to be main drivers for both survival and growth. In addition, interaction terms (between transfer in latitude and site altitude for survival, and transfer in latitude and temperature sum for growth) entail changed reaction patterns of the models depending on climatic conditions of the growing site. The new models behave in a way that corresponds well to previous studies and recommendations for both countries. The model performance was tested using selected plus-trees from open and control pollinated progeny tests. Results imply that the models are valid for both countries and perform well also for genetically improved material. These models are the first step in developing common deployment recommendations for genetically improved forest regeneration material in both Sweden and Finland.

  • Berlin, Uppsala Science Park, SE-75183 Uppsala, Sweden E-mail: mats.berlin@skogforsk.se (email)
  • Persson, Skogforsk, Box 3, SE-91821 Sävar, Sweden E-mail: torgny.persson@skogforsk.se
  • Jansson, Uppsala Science Park, SE-75183 Uppsala, Sweden E-mail: gunnar.jansson@skogforsk.se
  • Haapanen, Natural Resources Institute Finland (Luke), Green Technology, Box 18, FI-01301 Vantaa, Finland E-mail: matti.haapanen@luke.fi
  • Ruotsalainen, Natural Resources Institute Finland (Luke), Green Technology, Finlandiantie 18, FI-58450 Punkaharju, Finland E-mail: seppo.ruotsalainen@luke.fi
  • Bärring, Rossby Centre, Swedish Meteorological and Hydrological Institute, Folkborgsvägen 17, SE-60176 Norrköping, Sweden E-mail: lars.barring@smhi.se
  • Andersson Gull, Skogforsk, Box 3, SE-91821 Sävar, Sweden E-mail: bengt.andersson@skogforsk.se
article id 1516, category Research article
Hamed Yousefzadeh, Abasalt Hosseinzadeh Colagar, Fatemeh Fallah. (2016). Genetic diversity of geographically isolated Iranian populations of Betula pendula Roth: implications for conservation. Silva Fennica vol. 50 no. 3 article id 1516. https://doi.org/10.14214/sf.1516
Keywords: genetic differentiation; habitat isolation; haplotype diversity; genetic drift; long-term isolation
Highlights: The Iranian populations of birches exhibited high levels of genetic diversity, population differentiation, and the presence of unique haplotypes; The high genetic differentiation amongst the populations may contribute to the local geographical structure and poor gene flow amongst individuals; The results can potentially be used to adopt appropriate strategies for the conservation and management of isolated tree populations.
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The effects of long-term habitat fragmentations on genetic and population differentiation of Betula pendula Roth were investigated using chloroplast DNA (cpDNA) variations. Leaf samples were collected from four small remnant populations across the north of Iran. Three pairs of universal primers were used to amplify cpDNA, large single copy regions of trnC-trnD, trnK1-trnK2 and trnD-trnT. A total of 18 of the cpDNA haplotypes in the four populations were identified, however, no clear phylogeographic structuring of haplotypes could be detected. The total genetic diversity (HT) for all populations was high (0.932). Average intra-population genetic diversity was estimated as HS = 0.729 and average differentiation of populations GST = 0.218. Mantel tests of isolation by distance revealed a significant relationship between Wright’s inbreeding coefficient (Fst) and geographical distances for the four populations in Iran (r = 0.77, p < 0.05). The results of the hierarchical analysis of molecular variance (AMOVA) indicated that a 66% variation was partitioned within populations, whilst the variance amongst the four populations was only 34%. We suggest that significant genetic differentiation amongst populations can likely be attributed to reduced gene flow as a result of habitat fragmentation.

  • Yousefzadeh, Department of Forestry, Faculty of Natural Resources, Tarbiat Modares University, Nour, Mazandaran, Iran E-mail: h.yousefzadeh@modares.ac.ir (email)
  • Hosseinzadeh Colagar, Department of Molecular and Cell Biology; Faculty of Basic Sciences, University of Mazandaran, 47416-95447 Babolsar, Iran E-mail: ahcolagar@umz.ac.ir
  • Fallah, Department of Molecular and Cell Biology; Faculty of Basic Sciences, University of Mazandaran, 47416-95447 Babolsar, Iran E-mail: fatemehfalah69@yahoo.com
article id 1510, category Research article
Tähti Pohjanmies, Sakina Elshibli, Pertti Pulkkinen, Mari Rusanen, Pekka Vakkari, Helena Korpelainen, Tomas Roslin. (2016). Fragmentation-related patterns of genetic differentiation in pedunculate oak (Quercus robur) at two hierarchical scales. Silva Fennica vol. 50 no. 2 article id 1510. https://doi.org/10.14214/sf.1510
Keywords: marginal populations; Finland; genetic diversity; microsatellites
Highlights: While long-lived, widespread tree species should be resistant to genetic impoverishment, we detected high differentiation among populations and pronounced genetic structure within populations of Quercus robur in Finland; These patterns seem indicative of population processes active at range margins, and of disequilibrium following historic habitat change; Preservation of remaining genetic variation is thus important in the conservation of Q. robur.
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Populations at species’ range margins are expected to show lower genetic diversity than populations at the core of the range. Yet, long-lived, widespread tree species are expected to be resistant to genetic impoverishment, thus showing comparatively high genetic diversity within populations and low differentiation among populations. Here, we study the distribution of genetic variation in the pedunculate oak (Quercus robur L.) at its range margin in Finland at two hierarchical scales using 15 microsatellite loci. At a regional scale, we compared variation within versus among three oak populations. At a landscape scale, we examined genetic structuring within one of these populations, growing on an island of ca 5 km2. As expected, we found the majority of genetic variation in Q. robur to occur within populations. Nonetheless, differentiation among populations was markedly high (FST = 0.12) compared with values reported for populations of Q. robur closer to the core of its range. At the landscape level, some spatial and temporal sub-structuring was observed, likely explained by the history of land-use on the island. Overall, Q. robur fulfils the expectation of the central-marginal hypothesis of high differentiation among marginal populations, but the notable population differentiation has most likely been influenced also by the long, ongoing fragmentation of populations. Finnish oak populations may still be adjusting to the drastic habitat changes of the past centuries. Preservation of genetic variation within the remaining stands is thus an important factor in the conservation of Q. robur at its range margin.

  • Pohjanmies, University of Helsinki, Department of Agricultural Sciences, Spatial Foodweb Ecology Group, P.O. Box 27, FI-00014 University of Helsinki, Finland; University of Jyväskylä, Department of Biological and Environmental Sciences, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: tahti.t.pohjanmies@jyu.fi (email)
  • Elshibli, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 18, FI-01301 Vantaa, Finland; University of Helsinki, Department of Agricultural Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: sakina.elshibli@helsinki.fi
  • Pulkkinen, Natural Resources Institute Finland (Luke), Green technology, Haapastensyrjäntie 34, FI-12600 Läyliäinen, Finland E-mail: pertti.pulkkinen@luke.fi
  • Rusanen, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: mari.rusanen@luke.fi
  • Vakkari, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: pekka.vakkari@luke.fi
  • Korpelainen, University of Helsinki, Department of Agricultural Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: helena.korpelainen@helsinki.fi
  • Roslin, University of Helsinki, Department of Agricultural Sciences, Spatial Foodweb Ecology Group, P.O. Box 27, FI-00014 University of Helsinki, Finland; Swedish University of Agricultural Sciences, Department of Ecology, P.O. Box 7044, SE-750 07 Uppsala, Sweden E-mail: tomas.roslin@helsinki.fi
article id 1410, category Research article
Seppo Nevalainen, Juho Matala, Kari T. Korhonen, Antti Ihalainen, Ari Nikula. (2016). Moose damage in National Forest Inventories (1986–2008) in Finland. Silva Fennica vol. 50 no. 2 article id 1410. https://doi.org/10.14214/sf.1410
Keywords: Populus tremula; Pinus sylvestris; regeneration; soil preparation; thinning; Betula spp.; Keywords Alces alces; seedling stands; tree species mixture
Highlights: Almost 100 000 stands were studied; The proportion of damage doubled during the study period; Tree species mixture had a clear effect on the damage frequency; The damage was more common in mineral soils than in peatlands, in artificially than in naturally regenerated stands and in stands that needed thinning or clearing or in which soil preparation was used.
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The occurrence of moose damage was studied using data from three National Forest Inventories (NFIs) accomplished between 1986 and 2008 in Finland. The combined data included a total of 97 390 young stands. The proportion of moose damage increased from 3.6% to 8.6% between the 8th NFI (1986–1994) and the 10th NFI (2004–2008). The majority (75%) of the damage occurred in Scots pine-dominated stands. The proportion of damage was higher in aspen-dominated stands than in stands dominated by any other tree species. The tree species mixture also had a clear effect on the occurrence of damage. Pure Scots pine stands had less damage than mixed Scots pine stands, and moose damage decreased linearly with the increasing proportion of Scots pine. Stands on mineral soil had more frequent moose damage than stands on peatlands. The fertility class of the site had no straightforward effect on the damage frequency. Artificially regenerated stands had more damage than naturally regenerated stands. Accomplished soil preparation measures and the need for thinning or clearing operations increased moose damage. High proportions of moose damage in young stands were found around the country. In the 10th NFI, the largest concentration of damage was found in southwestern Finland. Our study shows the temporal and spatial changes in the occurrence of moose damage and pinpoints some important silvicultural factors affecting the relative risk of young stands over a large geographical area.

  • Nevalainen, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: seppo.nevalainen@luke.fi (email)
  • Matala, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: juho.matala@luke.fi
  • Korhonen, Natural Resources Institute Finland (Luke), Economics and society, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: kari.t.korhonen@luke.fi
  • Ihalainen, Natural Resources Institute Finland (Luke), Economics and society, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: antti.ihalainen@luke.fi
  • Nikula, Natural Resources Institute Finland (Luke), Economics and society, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: ari.nikula@luke.fi
article id 1323, category Research article
Tiina Laine, Kalle Kärhä, Antti Hynönen. (2016). A survey of the Finnish mechanized tree-planting industry in 2013 and its success factors. Silva Fennica vol. 50 no. 2 article id 1323. https://doi.org/10.14214/sf.1323
Keywords: regeneration; boreal; forestry; silviculture; mechanization; planting machines; critical success factors (CSFs)
Highlights: In 2013, 31 planting machines were operated by 22 businesses and planted 4.7 million seedlings on 2663 hectares in Finland; Critical success factors included expertise of planting machine operators, high quality planting, adequate amount of work, stoniness, and removal of slash; Growth of the industry will depend on improved cost-efficiency, appropriate worksites, marketing, development of planting machines.
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The aim of the study was to update the information pertaining to mechanized tree-planting activity in Finland in 2013 and its success factors. All businesses providing a mechanized tree-planting service were interviewed and asked to describe their equipment and activities, identify critical success factors (CSFs), and suggest areas for improvement. In 2013, 31 planting machines (18 Bracke P11.a, 11 M-Planter and 2 Risutec) operated by 22 businesses planted approximately 4.7 million seedlings on 2663 hectares. CSFs included expertise of planting machine operators, high quality planting, adequate amount of work, stoniness, and removal of slash. Based on the survey, some recommendations for improving mechanized planting work can be made. Firstly, improving the cost-efficiency of mechanized planting is necessary to enhance businesses’ profitability. Secondly, worksite selection is crucial as stoniness, stumps and slash debris diminish productivity. Lastly, the popularity of mechanized planting in the future will benefit from more marketing. Many businesses were unwilling to increase the area of service, invest in new equipment, or increase the volume of planting work but they believed that mechanized planting will become more popular in the near future.

  • Laine, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: tiina.laine@luke.fi (email)
  • Kärhä, Stora Enso Wood Supply Finland, P.O. Box 309, FI-00101 Helsinki, Finland E-mail: kalle.karha@storaenso.com
  • Hynönen, University of Eastern Finland, Faculty of Science and Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hynonena@gmail.com
article id 1408, category Research article
Anna Katharina Franke, Pasi Aatsinki, Ville Hallikainen, Esa Huhta, Mikko Hyppönen, Vesa Juntunen, Kari Mikkola, Seppo Neuvonen, Pasi Rautio. (2015). Quantifying changes of the coniferous forest line in Finnish Lapland during 1983–2009. Silva Fennica vol. 49 no. 4 article id 1408. https://doi.org/10.14214/sf.1408
Keywords: Pinus sylvestris; Picea abies; tree line; forest regeneration; environmental change; stand volume
Highlights: Volume of the growing stock of spruce and pine has increased in forests and in timber lines during the past 26 years; Spruce stem numbers increased on average, while pine stem numbers remained stable and location-specific variation was observed; Presuming that the ongoing trend of increasing temperature will remain, the enhanced forest regeneration and growth may result in extension of forests in the future.
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The boreal timber- and tree-line forests grow in harsh environmental conditions in their outermost distribution limit. Here even small environmental changes may cause dramatic changes in the distribution of tree species. We examined changes of the forest lines of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) in Finnish Lapland five times during 1983–2009. We monitored the number of stems and the volume of the growing stock in thirteen different locations in forest-line areas. The linear temporal trends and the variations of these response variables were used as indicators of a possible change during the study period. Spruce showed a significant increase both in the volume of the growing stock (up to 40% increase) and in the total stem number (up to 100% increase). A significant increase in the volume of the growing stock was observed in the pine data as well (up to 70% increase), whereas the stem number stagnated or even decreased. The results suggest that spruce needs favourable conditions to have an abundant regeneration, but after the establishment the seedlings seem to be more resistant against biotic and abiotic disturbances than pine seedlings. The increasing stand volume might result in a climate-related northward and upward extension of forests in the future. However, our results show that responses in the boreal forest line are species and location specific and a more favourable climate does not necessarily lead to an advance of the coniferous forest line.

  • Franke, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Eteläranta 55, FI-96301 Rovaniemi, Finland E-mail: anna.franke@fau.de (email)
  • Aatsinki, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Eteläranta 55, FI-96301 Rovaniemi, Finland E-mail: pasi.aatsinki@luke.fi
  • Hallikainen, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Eteläranta 55, FI-96301 Rovaniemi, Finland E-mail: ville.hallikainen@luke.fi
  • Huhta, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Eteläranta 55, FI-96301 Rovaniemi, Finland E-mail: esa.huhta@luke.fi
  • Hyppönen, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Eteläranta 55, FI-96301 Rovaniemi, Finland E-mail: mikko.hypponen@luke.fi
  • Juntunen, The Sámi Education Institute, Menesjärventie 4, P.O. Box 50, FI-99871 Inari, Finland E-mail: vesa.juntunen@sogsakk.fi
  • Mikkola, Natural Resources Institute Finland (Luke), Economics and society, Eteläranta 55, FI-96301 Rovaniemi, Finland E-mail: kari.mikkola@luke.fi
  • Neuvonen, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, P.O. Box 68, FI-80101, Joensuu, Finland E-mail: seppo.neuvonen@luke.fi
  • Rautio, Natural Resources Institute Finland (Luke), Bio-based business and industry, Eteläranta 55, FI-96301 Rovaniemi, Finland E-mail: pasi.rautio@luke.fi
article id 1283, category Research article
Ivana Bjedov, Dragica Obratov–Petković, Danijela Mišić, Branislav Šiler, Jelena M Aleksic. (2015). Genetic patterns in range-edge populations of Vaccinium species from the central Balkans: implications on conservation prospects and sustainable usage. Silva Fennica vol. 49 no. 4 article id 1283. https://doi.org/10.14214/sf.1283
Keywords: marginal populations; genetic structure; Vaccinium sp.; the Balkans; RAPD markers; genetic profiles; interspecific hybridization
Highlights: We studied fragmentary distributed range-edge populations of Vaccinium myrtillus, Vaccinium uliginosum and Vaccinium vitis-idaea from the Balkans using RAPDs; Low genetic diversities and high genetic differentiation were found in all species; The prevalence of clonal individuals was not observed; Past interspecific hybridization among V. vitis-idaea and the other two species was detected; Guidelines for conservation and sustainable usage were provided.
Abstract | Full text in HTML | Full text in PDF | Author Info

Vaccinium myrtillus L., Vaccinium uliginosum L. and Vaccinium vitis-idaea L. are perennial, cold-adapted clonal shrubs distributed throughout Europe, northern Asia and North America. Due to their usage in food (berries) and pharmaceutical industry (berries and leaves), their natural populations are exposed to anthropogenic and other impacts that affect their genetic make-up. We analyzed 14 fragmentary distributed and small-sized peripheral populations of these species from the Balkans, which represents the southeastern-European marginal area of their wide European distributions, using RAPD molecular markers. The contemporary genetic patterns in all three species within the Balkans were generally similar, and in comparison to previous reports on populations of these species found in northward Europe, where they have a more continuous distribution, the levels of genetic diversity were more or less halved, genetic differentiation was several times higher, gene flow exceptionally low, and the expected prevalence of clonal individuals was lacking. The population dynamics of all three species within the Balkans was complex and distinct, and was characterized by a past admixture of individuals from discrete populations of the same species and interspecific hybridisation not only between V. myrtillus and V. vitis-idaea but also between V. uliginosum and V. vitis-idaea, the latter not being reported to date. Conservation measures suitable for preservation of presumably genetically distinct portions of the Balkans’ gene pools of studied species have been suggested, while the utility of interspecific hybrids in breeding programs and/ or in food/pharmaceutical industry is yet to be assessed. 

  • Bjedov, University of Belgrade, Faculty of Forestry, Kneza Višeslava 1, 11000 Belgrade, Serbia E-mail: ivana.bjedov@sfb.bg.ac.rs
  • Obratov–Petković, University of Belgrade, Faculty of Forestry, Kneza Višeslava 1, 11000 Belgrade, Serbia E-mail: dragica.obratov-petkovic@sfb.bg.ac.rs
  • Mišić, University of Belgrade, Institute for Biological Research “Siniša Stanković”, Boulevard Despota Stefana 142, 11000 Belgrade, Serbia E-mail: dmisic@ibiss.bg.ac.rs
  • Šiler, University of Belgrade, Institute for Biological Research “Siniša Stanković”, Boulevard Despota Stefana 142, 11000 Belgrade, Serbia E-mail: branislav.siler@ibiss.bg.ac.rs
  • Aleksic, University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Vojvode Stepe 444a, P.O. Box 23, 11010 Belgrade, Serbia E-mail: aleksic_jelena@yahoo.com.au (email)
article id 1236, category Research article
Monika Litkowiec, Beata P. Plitta-Michalak, Andrzej Lewandowski, Grzegorz Iszkuło. (2015). Homogenous genetic structure in populations of Taxus baccata with varied proportions of male and female individuals. Silva Fennica vol. 49 no. 4 article id 1236. https://doi.org/10.14214/sf.1236
Keywords: genetic diversity; dioecy; English yew; Poland; sex ratio; nSSR markers
Highlights: Polish populations of Taxus baccata showed a high level of genetic diversity within populations and moderate genetic differentiation between them after nSSR marker testing; No significant differences in the genetic variation between T. baccata male and female individuals were observed, and microsatellite loci neutrality was verified; Determining the sex ratio in T. baccata populations is not essential to develop a clear understanding of genetic differentiation and diversity within and between populations of this species.
Abstract | Full text in HTML | Full text in PDF | Author Info

English yew (Taxus baccata L.) is a strictly outcrossing and dioecious species whose populations are small and isolated. It is known that sex ratios may vary in natural populations due to local environmental conditions or stochastic events. However, unbalanced sex ratios may have negative impacts on genetic diversity through enhanced genetic drift and inbreeding. The present study represents one of the first attempts to compare the genetic variation at microsatellite loci within and between populations with different gender proportions. Our results indicated that there were no significant correlations between sex ratio and the extent of genetic variation in different populations. All populations exhibited high levels of genetic diversity. Additionally, the genetic structure was characterized separately in male and female individuals. Statistical analyses of the set estimators describing the genetic structure of male and female individuals of T. baccata revealed no significant differences between the two groups. Molecular analysis verified that microsatellite nuclear loci neutrality developed for T. baccata, as there were no significant differences in the genetic variation between males and females and no evidence for any outlier loci using coalescent and hierarchical Bayesian simulations. The results demonstrate that ignoring biased sex ratios in T. baccata populations had no effect on the assessment of genetic differentiation and genetic diversity within and between populations of this species. These results are discussed with regards to the practical application of molecular markers in conservation programs.

  • Litkowiec, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: mlit@man.poznan.pl (email)
  • Plitta-Michalak, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: beata-plitta@wp.pl
  • Lewandowski, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: alew@man.poznan.pl
  • Iszkuło, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland & University of Zielona Góra, Faculty of Biological Sciences, Prof. Z. Szafrana 1, 65-516 Zielona Góra, Poland E-mail: iszkulo@man.poznan.pl
article id 1302, category Research article
Nils Fahlvik, Per Magnus Ekö, Nils Petersson. (2015). Effects of precommercial thinning strategies on stand structure and growth in a mixed even-aged stand of Scots pine, Norway spruce and birch in southern Sweden. Silva Fennica vol. 49 no. 3 article id 1302. https://doi.org/10.14214/sf.1302
Keywords: yield; cleaning; heterogeneous forest; dimension distribution; growth simulator
Highlights: Precommercial thinning (PCT) was a useful tool to influence the stand structure in accordance to silvicultural goals; PCT had a great impact on tree species composition; The seemingly great potential to influence the structure of a heterogeneous, mixed stand was restrained by natural settings and unconditional considerations at PCT (e.g. tree vitality, stem quality, regular spacing).
Abstract | Full text in HTML | Full text in PDF | Author Info
Four different management strategies were applied to a young mixed stand of Scots pine (Pinus sylvestris L.), Norway spruce (Pices abies (L.) Karst.) and birch (Betula pendula Roth and Betula pubescens Ehrh.) in southern Sweden. All strategies included an initial precommercial thinning to ca. 2400 stems ha–1. The different aims were: (i) a conifer-dominated stand with focus on high productivity; (ii) a conifer-dominated stand with high quality timber; (iii) keeping a stem-wise species mixture; (iv) a mosaic-wise species mixture. Stem selection according to the different strategies were simulated with a starting point from plots with a 5 m radius. All strategies were applied to all of the plots. A growth simulator was used to simulate the stand development up to final felling. This study illustrates the possibilities for influencing the structure of a mixed stand through precommercial thinning. The study also illustrates the long-term effects on stand structure and volume yield by consequently applying a management strategy from precommercial thinning until final felling. Precommercial thinning was found to be a useful tool to influence the stand structure in accordance to the aims set. However, the opportunities for influencing the stand by precommercial thinning were restricted by natural settings and unconditional considerations (e.g. tree vitality, stem quality, regular spacing), beyond what could be judged from stand average data. The stem volume production during a rotation was 6% lower for (iii) and (iv) compared to (i) and (ii), mainly due to a greater proportion of birch in the former strategies.
  • Fahlvik, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: nils.fahlvik@slu.se (email)
  • Ekö, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: per.magnus.eko@slu.se
  • Petersson, StoraEnso Skog AB, Åsgatan 22, SE-791 80 Falun, Sweden E-mail: nils.petersson@storaenso.com
article id 1188, category Research article
Kristina Wallertz, Henrik Nordenhem, Göran Nordlander. (2014). Damage by the pine weevil Hylobius abietis to seedlings of two native and five introduced tree species in Sweden. Silva Fennica vol. 48 no. 4 article id 1188. https://doi.org/10.14214/sf.1188
Keywords: forest regeneration; conifer seedlings; defence; feeding damage; forest plantation; resistance
Highlights: Both native and introduced confer species in Sweden can be highly susceptible to damage by the pine weevil; Douglas fir and Sitka spruce were generally the most damaged among six studied conifer species; The results highlight some of the risks in establishing exotic tree species for forest production.
Abstract | Full text in HTML | Full text in PDF | Author Info
There is increasing interest in using introduced species in Swedish forestry in response to climate change, but it is important to assess their resistance to native pests. Thus, we compared the extent of pine weevil feeding on two dominant native conifers, Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.), the non-host deciduous broadleaf hybrid aspen (Populus × wettsteinii Hämet-Ahti) and four introduced conifers: Douglas fir (Pseudotsuga menziesii (Mirb.) Franco), hybrid larch (Larix × marschlinsii Coaz), Sitka spruce (Picea sitchensis (Bong.) Carriére) and lodgepole pine (Pinus contorta Douglas ex Loudon). The extent of feeding damage on seedlings and its effect on their vitality were examined in a field study in south-central Sweden and a laboratory experiment, which gave largely consistent results. Generally, the species most heavily attacked by the pine weevil, in both experiments, were Douglas fir and Sitka spruce. In the field experiment pine weevils killed or severely damaged significantly higher proportions of Douglas fir and Sitka spruce seedlings (60%) than any other species except Norway spruce (49%). Among conifer seedlings the proportions of killed or severely damaged seedlings were lowest for Scots pine and hybrid larch (27%) and Lodgepole pine (36%). The results indicate that most conifer species planted on young clear-cuttings in Sweden need some kind of pine weevil protection, and the possibility that introducing new tree species might increase damage caused by pests must be considered. For instance, widespread use of hybrid aspen could reduce damage by pine weevils, but increase damage by other, untested pests or pathogens.
  • Wallertz, Unit for Field-based Forest Research, Swedish University of Agricultural Sciences (SLU), Asa Research Station, SE-36030 Lammhult, Sweden E-mail: kristina.wallertz@slu.se (email)
  • Nordenhem, Department of Ecology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7044, SE-75007 Uppsala, Sweden E-mail: henrik.nordenhem@slu.se
  • Nordlander, Department of Ecology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7044, SE-75007 Uppsala, Sweden E-mail: goran.nordlander@slu.se
article id 1161, category Research article
Tiina Laine, Veli-Matti Saarinen. (2014). Comparative study of the Risutec Automatic Plant Container (APC) and Bracke planting devices. Silva Fennica vol. 48 no. 3 article id 1161. https://doi.org/10.14214/sf.1161
Keywords: productivity; regeneration; cost-efficiency; planting cost; mechanized tree planting
Highlights: As currently designed, the prototype Risutec APC fitted with an automatic feeding system offers no significant advantage over the Bracke planting device in terms of planting productivity or quality; Cost estimates suggest that an idealized automated feeding system could increase productivity and decrease unit costs.
Abstract | Full text in HTML | Full text in PDF | Author Info
The productivity of mechanized planting could be increased by minimizing the time spent manually reloading seedling cassettes. This study compared the work-time distribution, productivity and quality of the prototype Risutec APC fitted with an automatic feeding system and the commonly-used and manually-loaded Bracke P11.a. An approach of comparative time study was employed that compared performance of two operators using both machines in four sites where slash and stumps had been removed. Operating costs were estimated and compared for these two machines and an idealized machine with automatic feeding system (referred as AUT). AUT was assumed to be similar to the Bracke planting machine with the only difference being in automatic feeding. Productivity of the Risutec APC (196 seedlings per productive work hour [pl PWh0–1]) was lower than that of Bracke (244 pl PWh0–1), making the unit cost 35.7% higher. A large portion (17.6%) of the productive work time of Risutec APC was interrupted by malfunctions, so it cannot be considered robust and reliable yet. Quality of the planting work was reasonable for both machines. The results suggest that an idealized AUT could increase planting capacity (hectares per year [ha yr–1]) by 15.4% and lower the unit cost (Euro per seedling [€ pl–1]) by 4.7% compared to today’s machines. The importance of an automated feeding system increases with planting efficiency because relatively more time is spent reloading seedlings. Proper automatic feeding system could offer a cost-effective solution and could enhance productivity, but the Risutec APC has yet to meet the technical and economic standards required to be competitive.
  • Laine, Finnish Forest Research Institute (METLA), Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: tiina.laine@metla.fi (email)
  • Saarinen, Finnish Forest Research Institute (METLA), Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: veli-matti.saarinen@metla.fi
article id 1073, category Research article
Pedro Sánchez-Gómez, Juan F. Jiménez, Juan B. Vera, Francisco J. Sánchez-Saorín, Juan F. Martínez, Joseph Buhagiar. (2013). Genetic structure of Tetraclinis articulata, an endangered conifer of the western Mediterranean basin. Silva Fennica vol. 47 no. 5 article id 1073. https://doi.org/10.14214/sf.1073
Keywords: conservation; genetic differentiation; genetic diversity; ISSR markers
Highlights: The employment of ISSR molecular markers has shown moderate genetic diversity and high genetic differentiation in Tetraclinis articulata; Genetic structure of populations seems to be influenced by the anthropogenic use of this species since historical times, or alternatively, by the complex palaeogeographic history of the Mediterranean basin; Results could be used to propose management policies for conservation of populations.
Abstract | Full text in HTML | Full text in PDF | Author Info
Tetraclinis articulata (Vahl) Masters is a tree distributed throughout the western Mediterranean basin. It is included in the IUCN (International Union for Conservation of Nature) red list, and protected by law in several of the countries where it grows. In this study we examined the genetic diversity and genetic structure of 14 populations of T. articulata in its whole geographic range using ISSR (inter simple sequence repeat) markers. T. articulata showed moderate genetic diversity at intrapopulation level and high genetic differentiation. The distribution of genetic diversity among populations did not exhibit a linear pattern related to geographic distances, since all analyses (principal coordinate analysis, Unweighted pair group method with arithmetic mean dendrogram and Bayesian structure analysis) revealed that spanish population grouped with Malta and Tunisia populations. Although it is possible that T. articulata earlier was natural in Southeast Spain, results suggest that the current population has been reintroduced into the Iberian Peninsula in historical times, due to its utility in mining and building. In addition, results could be used to propose management guidelines for the conservation of T. articulata.
  • Sánchez-Gómez, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain E-mail: psgomez@um.es
  • Jiménez, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain E-mail: fjimenez@um.es (email)
  • Vera, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain E-mail: jbveraperez@gmail.com
  • Sánchez-Saorín, Dirección General de Medio Ambiente, Consejería de Presidencia de la Región de Murcia, C/ Catedrático Eugenio Úbeda nº3, E-30071 Murcia, Spain E-mail: fjavier.sanchez3@carm.es
  • Martínez, Dirección General de Medio Ambiente, Consejería de Presidencia de la Región de Murcia, C/ Catedrático Eugenio Úbeda nº3, E-30071 Murcia, Spain E-mail: juanf.martinez@carm.es
  • Buhagiar, Argotti Herbarium and Gardens (UOM), Triq Vincenzo Bugeja Floriana VLT 16, Malta E-mail: joseph.buhagiar@um.edu.mt
article id 1016, category Research article
Karin Johansson, Eva Ring, Lars Högbom. (2013). Effects of pre-harvest fertilization and subsequent soil scarification on the growth of planted Pinus sylvestris seedlings and ground vegetation after clear-felling. Silva Fennica vol. 47 no. 4 article id 1016. https://doi.org/10.14214/sf.1016
Keywords: nitrogen; establishment; regeneration; Scots pine; disc trenching; carryover; competing vegetation
Highlights: Pre-harvest N fertilization had no significant effect on seedling growth and ground vegetation biomass; Scarification improved seedling survival and growth and reduced the amount of ground vegetation; Without scarification, pre-harvest fertilization increased the amount of damaged seedlings.
Abstract | Full text in HTML | Full text in PDF | Author Info
Fertilization and scarification are both performed to increase tree production at different stages of forest rotation periods. In this study, the effects of previous nitrogen fertilizations and scarification after clear felling on planted Pinus sylvestris L. seedlings and ground vegetation were investigated. Two fertilization experiments established around 1980 were harvested in 2006, after which the plots were scarified by disc trenching and re-planted. The plots had been repeatedly fertilized over a 20-year period before harvesting, with total N doses of 0, 450, 900 or 1800 kg N ha-1. After five growing seasons, the growth, survival and nutrient contents of the seedlings were measured, and ground vegetation was collected to estimate its biomass and nutrient content. Pre-harvest fertilization alone had only minor effects on the results, but scarification increased both the survival and growth of the planted seedlings. However, without scarification, seedling mortality increased with increasing fertilization intensity. The ground vegetation biomass was higher in plots without scarification, but the total biomass of seedlings and ground vegetation was similar in all treatments. Scarification thus favored seedling growth at the expense of ground vegetation. Only a few effects on nutrient content were found, but there were no signs of nutrient imbalance in any of the treatments. At higher levels of fertilization, the K:N ratio in the seedlings decreased while the K content in the ground vegetation increased. Overall, scarification had a greater impact than pre-harvest fertilization on the planted seedlings and the ground vegetation.
  • Johansson, Skogforsk, The Forestry Research Institute of Sweden, Ekebo 2250, SE-268 90 Svalöv, Sweden & Southern Swedish Forest Research Centre, SLU, Box 49, SE-230 53 Alnarp, Sweden E-mail: karin.johansson@skogforsk.se (email)
  • Ring,  Skogforsk, The Forestry Research Institute of Sweden, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: eva.ring@skogforsk.se
  • Högbom,  Skogforsk, The Forestry Research Institute of Sweden, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: lars.hogbom@skogforsk.se
article id 1005, category Research article
Marjut Turtiainen, Jari Miina, Kauko Salo, Juha-Pekka Hotanen. (2013). Empirical prediction models for the coverage and yields of cowberry in Finland. Silva Fennica vol. 47 no. 3 article id 1005. https://doi.org/10.14214/sf.1005
Keywords: generalized linear mixed model; abundance; berry yield; Vaccinium vitis-idaea L.
Highlights: The site fertility significantly affected the abundance of cowberry on mineral soils, spruce mires and pine mires; The stand basal area and dominant tree species were among the most important forest structural predictors in the model for the coverage; In the cowberry yield model developed for mineral soil sites, the stand basal area and coverage of cowberry plants were statistically significant predictors.
Abstract | Full text in HTML | Full text in PDF | Author Info
Empirical models for the coverage and berry yield of cowberry (Vaccinium vitis-idaea L.) were developed using generalized linear mixed models (GLMMs). The percentage coverage of cowberry was predicted as a function of site and stand characteristics using data from the Finnish National Forest Inventory (NFI) in 1995. The average annual yield, including the between-year variation in the yield, was predicted as a function of percentage coverage and stand characteristics using permanent experimental plots (MASI) established in different areas of Finland and measured in 2001-2012. The model for cowberry yields (Model 2) was developed for mineral soil forests. The model for the coverage (Model 1) was constructed so that it considers both mineral soil sites and also many other sites where cowberry occurs in the field layer. According to Model 1, the site fertility significantly affected the abundance of cowberry on mineral soils, spruce mires and pine mires. The stand basal area and dominant tree species were among the most important forest structural predictors in Model 1. The site fertility was not a significant predictor in the cowberry yield model. Instead, the stand basal area and coverage of cowberry plants were found to be statistically significant predictors in Model 2. The estimated models were used to predict the cowberry coverage, average annual yield and its 95 % confidence interval along with stand development. The models of this study can be used for multi-objective forest planning purposes.
  • Turtiainen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: marjut.turtiainen@uef.fi (email)
  • Miina, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jari.miina@metla.fi
  • Salo, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: kauko.salo@metla.fi
  • Hotanen, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: juha-pekka.hotanen@metla.fi
article id 928, category Research article
Rune Simonsen. (2013). Optimal regeneration method – Planting vs. natural regeneration of Scots pine in northern Sweden. Silva Fennica vol. 47 no. 2 article id 928. https://doi.org/10.14214/sf.928
Keywords: optimisation; silviculture; genetically improved planting material
Highlights: Two regeneration methods were modelled on stand level and optimised numerically to maximise present value for a range of site indexes and locations; Natural regeneration was optimal in most cases; Planting was optimal for high site indexes, low rate of seedling mortality and for low discount rates; Using genetically improved plant material greatly shifts the preference towards planting
Abstract | Full text in HTML | Full text in PDF | Author Info
In this study the profitability of regenerating Scots pine (Pinus sylvestris L.) was examined for two methods; planting and natural regeneration with seed trees. The methods were modelled on stand level and optimised numerically using nonlinear optimisation. The analysis includes 7 site indexes, 16 to 28 expressed as dominant height in meters at an age of 100 years; and 8 localities in northern Sweden distributed on two latitudes, 60°N and 64°N and four altitudes, 100 to 400 m.a.s.l. Furthermore, two scenarios of genetically improved planting material were examined. The results show that the optimal choice of regeneration method depends on the location, site index and discount rate. Considering the same genetic regeneration material, natural regeneration was the optimal method for most of the evaluated sites. Planting was optimal only for stands of high site index and low rate of seedling mortality, which is associated with localities on low altitudes. The break even site index, where the two methods yielded the same net present value, was 27 on average (25 to 28). The choice between the two regeneration methods was found to be more economically important when the discount rate was low and for low site indexes. The option of using genetically improved plant material shift the preference towards planting. Thus, the two levels of genetic gain of +4% and +10% to maximum mean annual increment resulted in an average break even site index of 25 and 21 respectively.
  • Simonsen, Department of Forest Economics, SLU, SE-901 83 Umeå, Sweden E-mail: rune.simonsen@slu.se (email)
article id 920, category Research article
Hannu Hökkä, Jaakko Repola, Mikko Moilanen, Markku Saarinen. (2012). Seedling establishment on small cutting areas with or without site preparation in a drained spruce mire – a case study in northern Finland. Silva Fennica vol. 46 no. 5 article id 920. https://doi.org/10.14214/sf.920
Keywords: Picea abies; site preparation; canopy gaps; natural regeneration; drained peatlands; seedling establishment; clear-cut
Abstract | View details | Full text in PDF | Author Info
A large proportion of drained spruce mire stands is currently approaching regeneration maturity in Finland. We studied the effect of cutting – small canopy openings (78, 177, and 314 m2) and small clear-cuts (0.25–0.37 ha) – with or without site preparation (scalping) on the establishment of natural Norway spruce seedlings in one experimental drained spruce mire stand in northern Finland. The cuttings were made in winter 2004–2005 and site preparation with scalping in early June 2005. The experimental design was composed of four blocks with altogether four clear-cuts and 33 canopy openings. The seedling establishment was surveyed annually (2006, 2008–2010) from five circular sample plots (one 10 m2 and four 5 m2 plots in size) located within the canopy openings and from 18 circular 5 m2 sample plots systematically located in the scalped and untreated halves of the clear-cuts. Site preparation was found unnecessary, because it resulted in a clearly lower number of seedlings in the openings. A slight negative effect was also found in the clear-cuts. In the two years following the cuttings, the number of seedlings increased quickly in the canopy openings, but more gradually in the clear-cut areas. In 2010, on average 15 500 new seedlings were observed in the canopy openings and 6700 in the clear-cut areas, of which 5050 and 1200, respectively, were >0.1 m tall spruces. The proportion of birch increased in the last two years, being ca. 22% in the openings and 45% in the clear-cuts in 2010. The spatial distribution of seedlings was more uneven in the clear-cuts than in the openings, with 41% and 20% of survey plots empty, respectively.
  • Hökkä, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: hannu.hokka@metla.fi (email)
  • Repola, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: jaakko.repola@metla.fi
  • Moilanen, Finnish Forest Research Institute, Oulu Unit, P.O. Box 413, FI-90014 University of Oulu, Finland E-mail: mikko.moilanen@metla.fi
  • Saarinen, Finnish Forest Research Institute, Parkano Unit, Kaironiementie 15, FI-39700 Parkano, Finland E-mail: markku.saarinen@metla.fi
article id 905, category Research article
Katarzyna A. Jadwiszczak, Danuta Drzymulska, Agata Banaszek, Piotr Jadwiszczak. (2012). Population history, genetic variation and conservation status of the endangered birch species Betula nana L. in Poland. Silva Fennica vol. 46 no. 4 article id 905. https://doi.org/10.14214/sf.905
Keywords: Betula nana; genetic diversity; microsatellites; conservation genetics; cpDNA; isolation
Abstract | View details | Full text in PDF | Author Info
The effective conservation of species requires data on the levels and distribution of genetic diversity within and among populations. In this study, we estimated the genetic variation in three isolated populations of Betula nana in Poland. An analysis of 11 nuclear microsatellites revealed moderate mean heterozygosities (HO=0.556, HE=0.562), low mean number of alleles per locus (A=4.57) and no inbreeding in the total sample. An M-ratio test indicated that each population had experienced a severe bottleneck in the past. Tests for heterozygosity excess revealed that a significant decrease in the numbers of individuals in two populations had occurred quite recently. The large number of private alleles and very restricted number of migrants between populations (Nm=0.35) strongly suggest that genetic drift and geographic isolation are the primary factors responsible for the reduction of genetic variation in the Polish populations of B. nana. We detected two cpDNA haplotypes in the study populations, which can be explained in terms of either the genetic drift acting on the relict localities or a postglacial recolonisation from distinct refugia. Palynological data indicated that one refugium could be located in the Carpathians and their northern foreland. The primary threat to B. nana in Poland is the overgrowth of its habitats by competing species, which has likely resulted in a lack of generative reproduction in the mountain populations.
  • Jadwiszczak, Institute of Biology, University of Białystok, wierkowa 20B, 15-950 Białystok, Poland E-mail: kszalaj@uwb.edu.pl (email)
  • Drzymulska, Institute of Biology, University of Białystok, wierkowa 20B, 15-950 Białystok, Poland E-mail: dd@nn.pl
  • Banaszek, Institute of Biology, University of Białystok, wierkowa 20B, 15-950 Białystok, Poland E-mail: ab@nn.pl
  • Jadwiszczak, Institute of Biology, University of Białystok, wierkowa 20B, 15-950 Białystok, Poland E-mail: pj@nn.pl
article id 64, category Research article
Karin Johansson, Ola Langvall, Johan Bergh. (2012). Optimization of environmental factors affecting initial growth of Norway spruce seedlings. Silva Fennica vol. 46 no. 1 article id 64. https://doi.org/10.14214/sf.64
Keywords: fertilization; establishment; irrigation; regeneration; seedling types; vegetation management
Abstract | View details | Full text in PDF | Author Info
  • Johansson, Skogforsk, Svalöv, Sweden E-mail: karin.johansson@skogforsk.se (email)
  • Langvall, SLU, Asa Forest Research Station, Sweden E-mail: ol@nn.se
  • Bergh, SLU, Southern Swedish Forest Research Centre, Sweden E-mail: jb@nn.se
article id 63, category Research article
Leena Koivuranta, Tarja Latva-Karjanmaa, Pertti Pulkkinen. (2012). The effect of temperature on seed quality and quantity in crosses between European (Populus tremula) and hybrid aspens (P. tremula x P. tremuloides). Silva Fennica vol. 46 no. 1 article id 63. https://doi.org/10.14214/sf.63
Keywords: climate change; gene flow; germination; hybrid vigour
Abstract | View details | Full text in PDF | Author Info
Hybrid aspen (Populus tremula L. Populus tremuloides Michx.) plantations are expanding in Fennoscandia and the Baltic countries; however, the possible effects of plantations on the native European aspen (P. tremula) and the level of gene flow between European and hybrid aspen have not been investigated. We studied seed quantity and quality in intraspecific and interspecific crosses of the European and hybrid aspens over a two year period. In order to study whether elevated temperatures due to climate change would benefit the species differently, we performed the crosses in different temperatures. In both years, interspecific crosses produced more seeds with higher quality than intraspecific crosses. This result was most distinct in crosses between female hybrid aspen and male European aspen. In higher temperatures, relative germination difference between hybrid aspen seeds and seeds from P. tremula P. tremula crosses seems to increase. These results suggest that hybrid aspen may have a significant genetic impact on the European aspen, and this effect may be strengthened by climate warming.
  • Koivuranta, Finnish Forest Research Institute, Haapastensyrjä, Finland E-mail: lk@nn.fi
  • Latva-Karjanmaa, Finnish Forest Research Institute, Haapastensyrjä, Finland E-mail: tlk@nn.fi
  • Pulkkinen, Finnish Forest Research Institute, Haapastensyrjä, Finland E-mail: pertti.pulkkinen@metla.fi (email)
article id 87, category Research article
Radek Bace, Miroslav Svoboda, Pavel Janda. (2011). Density and height structure of seedlings in subalpine spruce forests of Central Europe: logs vs. stumps as a favourable substrate. Silva Fennica vol. 45 no. 5 article id 87. https://doi.org/10.14214/sf.87
Keywords: Norway spruce; Picea abies; coarse woody debris; microsite; natural regeneration
Abstract | View details | Full text in PDF | Author Info
Decaying logs and stumps provide an important seedling substrate in natural subalpine forests. However, only stumps present such a role in managed forests. The aim of this study was to assess the differences in the process of seedling colonization between logs and stumps. The study was carried out in the Czech Republic, in two old-growth subalpine spruce forests located in the Bohemian Forest and Ash Mts., dominated by Athyrium distentifolium Opiz and Vaccinium myrtillus L. undergrowth, respectively. Norway spruce (Picea abies (L.) Karst.) regeneration growing on logs, stumps and non-coarse woody debris (CWD) microsites was surveyed. Regeneration (height 0–2.0 m) densities exceeded 5000 individuals per ha on both sites. The average density of P. abies regeneration per square meter of substrate was 0.3-5.7-19.6 and 0.5-3.8-11.0 on non-CWD microsites, logs and stumps, located in A. distentifolium and V. myrtillus undergrowth, respectively. Stumps and non-CWD microsites dominated by V. myrtillus, supported a higher proportion of taller seedlings per plot compared to the small seedlings growing on logs and non-CWD dominated by A. distentifolium ground-cover. The disproportion in regeneration densities between the stumps and the original logs decreased with increasing stages of decay. The tallest regeneration growing on stumps (root-soil plates) was significantly older than that growing on the logs (stems). Based on these two latter findings, the stumps appeared to provide suitable seedling substrates several years earlier than the logs did. Therefore, we conclude that the stumps play a more important role (relative to their covered area, 21–28 m2 ha–1) in terms of suitable microsites for regeneration, than the logs do.
  • Bace, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: bace@fld.czu.cz (email)
  • Svoboda, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: ms@nn.cz
  • Janda, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: pv@nn.cz
article id 98, category Research article
Meeri Pearson, Markku Saarinen, Kari Minkkinen, Niko Silvan, Jukka Laine. (2011). Mounding and scalping prior to reforestation of hydrologically sensitive deep-peated sites: factors behind Scots pine regeneration success. Silva Fennica vol. 45 no. 4 article id 98. https://doi.org/10.14214/sf.98
Keywords: soil preparation; peatland forest regeneration; mound; scalp; Scots pine; OM decomposition; excess moisture
Abstract | View details | Full text in PDF | Author Info
Watering up typically ensues after clearcutting forestry-drained peatland forests. Thus, the effectiveness of maintenance drainage and soil preparation procedures becomes paramount for establishing a new generation of commercial forest. Mounding is the primary method of soil preparation applied in regeneration sites lying on deep peat. As raised planting spots, mounds are resistant to waterlogging and assumed to be beneficial for organic matter (OM) decomposition via, e.g., increased soil aeration and temperature, which would also enhance seedling growth. In recent years, however, less intensive and cheaper alternatives like scalping have been sought with some reported cases of success. Our case study investigated the survival and growth of Scots pine outplants in mounds, scalps, and unprepared microsites along a moisture gradient. After three growing seasons, mounding accelerated neither seedling growth nor OM decomposition relative to the unprepared treatment. Survival in mounds was nonetheless superior overall. Scalps behaved as water collecting depressions leading to a catastrophic regeneration result. Based on our findings, water table level (WTL) overrides other growth-controlling factors in excess moisture conditions. To combat watering up coupled with greater than normal rainfall, we recommend reforestation strategies which provide elevated, prepared planting spots (i.e., mounds) or utilize unprepared, higher microforms.
  • Pearson, Finnish Forest Research Institute, Western Finland Regional Unit, Kaironiementie 15, FI-39700 Parkano, Finland E-mail: meeri.pearson@metla.fi (email)
  • Saarinen, Finnish Forest Research Institute, Western Finland Regional Unit, Kaironiementie 15, FI-39700 Parkano, Finland E-mail: ms@nn.fi
  • Minkkinen, University of Helsinki, Department of Forest Sciences, Helsinki, Finland E-mail: km@nn.fi
  • Silvan, Finnish Forest Research Institute, Western Finland Regional Unit, Kaironiementie 15, FI-39700 Parkano, Finland E-mail: ns@nn.fi
  • Laine, Finnish Forest Research Institute, Western Finland Regional Unit, Kaironiementie 15, FI-39700 Parkano, Finland E-mail: jl@nn.fi
article id 97, category Research article
Hannu Hökkä, Jaakko Repola, Mikko Moilanen, Markku Saarinen. (2011). Seedling survival and establishment in small canopy openings in drained spruce mires in Northern Finland. Silva Fennica vol. 45 no. 4 article id 97. https://doi.org/10.14214/sf.97
Keywords: Picea abies; canopy gaps; natural regeneration; drained peatlands; seedling establishment
Abstract | View details | Full text in PDF | Author Info
A large proportion of drained spruce mire stands is currently approaching regeneration maturity in Finland. Traditional regeneration methods with effective site preparation and planting generally result in satisfactory seedling stands also in spruce mires. However, natural regeneration methods may be more appropriate in protecting watercourses and minimizing regeneration costs. We studied the survival of advance growth and establishment of new seedlings in small canopy openings that were cut at three different diameters in two experimental drained spruce mire stands in Northern Finland (Tervola and Oulu) in 2004. The number of seedlings was repeatedly surveyed from five small circular plots (one 10 m2 and four 5 m2 plots in size) located within the opening. Advance growth which survived the cutting and new seedlings were separated in the surveys. The density of advance growth was on average 9000 ha–1 after cutting, and it decreased by 30% during the five-year monitoring period (2006–2010) due to natural mortality. The number of new seedlings increased rapidly within the three years after cutting the openings. In 2010, 11 000–26 000 new seedlings ha–1 in Tervola and 12 000–16 000 ha–1 in Oulu on average were observed. The size of the opening had no clear effect on the regeneration result. The proportion of birch of the new seedlings increased with time and opening size in Tervola. The results show that Norway spruce regenerates naturally in small canopy openings cut in mature drained spruce mire stands.
  • Hökkä, Finnish Forest Research Institute, Rovaniemi Research Unit, FI-96301 Rovaniemi, Finland E-mail: hannu.hokka@metla.fi (email)
  • Repola, Finnish Forest Research Institute, Rovaniemi Research Unit, FI-96301 Rovaniemi, Finland E-mail: jr@nn.fi
  • Moilanen, Finnish Forest Research Institute, Muhos Research Unit, Muhos, Finland E-mail: mm@nn.fi
  • Saarinen, Finnish Forest Research Institute, Parkano Research Unit, Parkano, Finland E-mail: ms@nn.fi
article id 94, category Research article
Youhong Peng, Ke Chen. (2011). Phylogeographic pattern of Populus cathayana in the southeast of Qinghai-Tibetan Plateau of China revealed by cpSSR markers. Silva Fennica vol. 45 no. 4 article id 94. https://doi.org/10.14214/sf.94
Keywords: genetic differentiation; refugia; phylogeography
Abstract | View details | Full text in PDF | Author Info
The vegetation in the Qinghai-Tibetan Plateau is thought to be highly sensitive and more vulnerable to global climate change than that of other areas. The uplift of the plateau as well as the climatic oscillations during glacial periods had a profound impact on plant species distribution and genetic diversity there. In the present study, seven pairs of cpSSR (chloroplast Simple Sequence Repeat) primers were utilized to detect genetic varieties of Populus cathayana Rehd populations from their natural range in the southeastern areas of Qinghai-Tibetan Plateau. A total of 28 alleles and 12 different haplotypes were detected. The proportion of haplotype variation among populations (GST = 0.794, NST = 0.900) indicated high level of genetic differentiation among populations and a significant phylogeographic structure (NST > GST, P < 0.05). This appears to support the hypothesis that these populations were derived from multiple refugia areas during the Quaternary climatic oscillations. Based on the haplotype network and mismatch distribution analyses, we found no evidence of postglacial range recolonization and expansion by P. cathayana in this region. This might be mainly due to the complex topography of the southeastern part of the Qinghai-Tibetan Plateau. The lofty mountain ranges and deep valleys in this region might have prevented long-distance migrations of this species during the climatic amelioration.
  • Peng, Chinese Academy of Sciences, Chengdu Institute of Biology, Chengdu, China E-mail: pengyh@cib.ac.cn (email)
  • Chen, Chinese Academy of Sciences, Chengdu Institute of Biology, Chengdu, China E-mail: kc@nn.cn
article id 29, category Research article
Piotr Androsiuk, Roman Zielinski, Kornelia Polok. (2011). B-SAP markers derived from the bacterial KatG gene differentiate populations of Pinus sylvestris and provide new insights into their postglacial history. Silva Fennica vol. 45 no. 1 article id 29. https://doi.org/10.14214/sf.29
Keywords: Pinus sylvestris; KatG gene; molecular markers; population differentiation; migrations
Abstract | View details | Full text in PDF | Author Info
The aim of the studies was to evaluate the efficiency of the KatG gene based B-SAP markers as a tool to distinguish morphologically diversified and geographically distant Scots pine populations and to track the routes of migrations. The 19 populations growing in the IUFRO 1982 provenance experiment and representing the natural distribution of the species in Europe were scored using 103 B-SAP loci. Among them 26% loci were polymorphic. The level of polymorphism was associated with the location of primers on the KatG template. The diversity was low, He = 0.086, and deposited mostly among populations. Seven unique markers were found that identified populations and likely they were associated with morphology. The overall genetic identity was relatively low, I = 0.933 (D = 0.069). The block of six B-SAP markers discriminated populations into two groups in agreement with their geographic origin and thereby further described as the North and the South. The North group was uniform with genetic diversity, He = 0.026 and the overall genetic distance D = 0.022. Presumably, it migrated from refugia in the Alps via France, northern Germany and Denmark, to Scandinavia and Russia. The South group was heterogeneous with He = 0.063 and D = 0.047. This group migrated from the Carpathians via Slovakia to Germany and Poland. The Balkans and Asian refugia did not take part in recolonization of Europe. The block of six B-SAP/KatG markers can be recommended for tracking postglacial history of Scots pine.
  • Androsiuk, University of Warmia and Mazury in Olsztyn, Department of Genetics, Plac Lodzki 3, 10-967 Olsztyn, Poland E-mail: pa@nn.pl
  • Zielinski, University of Warmia and Mazury in Olsztyn, Department of Genetics, Plac Lodzki 3, 10-967 Olsztyn, Poland E-mail: rz@nn.pl
  • Polok, University of Warmia and Mazury in Olsztyn, Department of Genetics, Plac Lodzki 3, 10-967 Olsztyn, Poland E-mail: kpolok@moskit.uwm.edu.pl (email)
article id 146, category Research article
Karri Uotila, Juho Rantala, Timo Saksa, Pertti Harstela. (2010). Effect of soil preparation method on economic result of Norway spruce regeneration chain. Silva Fennica vol. 44 no. 3 article id 146. https://doi.org/10.14214/sf.146
Keywords: Picea abies; soil preparation; cleaning; disc trenching; forestry investment analysis; pre-commercial thinning; regeneration chain; spot mounding; sprouting
Abstract | View details | Full text in PDF | Author Info
Economic result of forest regeneration chains, based either on spot mounding or on disc trenching and planting of Norway spruce (Picea abies [L.] Karst.) seedlings, were clarified and compared to each other. First, effects of soil preparation method on early development of Norway spruce stands were measured from field experiments. Second, the effects of soil preparation method on stand level management programs were modelled. The modelling was based on growth simulation and investment calculations. The soil preparation methods substantially affected early development of a stand. The density of the removed trees in early cleaning was 56% higher on the disc-trenched area compared to the spot-mounded area. The difference was especially high (120%), close by (< 25 cm) the remained spruce seedlings. There was also a difference between the methods in the growth of crop spruces; at biological age of 8 years, the mean height of spruce was 110 cm on the spot-mounded area and 68 cm on the disc-trenched area. The differences led to divergent management programs between the areas. The disc-trenched area needed three young stand management operations whereas two was enough at the spot-mounded area. Although disc trenching is a less expensive method than spot mounding, the total management costs were higher in disc trenching than in spot mounding. Furthermore, incomes from the first commercial thinning were higher when regeneration based on spot mounding. At the interest rate of 3%, the investment in spot mounding had 329 EUR ha–1 higher net present value than the investment in disc trenching.
  • Uotila, Finnish Forest Research Institute, Suonenjoki, Finland E-mail: karri.uotila@metla.fi (email)
  • Rantala, Finnish Forest Research Institute, Suonenjoki, Finland E-mail: jr@nn.fi
  • Saksa, Finnish Forest Research Institute, Suonenjoki, Finland E-mail: ts@nn.fi
  • Harstela, Finnish Forest Research Institute, Suonenjoki, Finland E-mail: ph@nn.fi
article id 152, category Research article
Torgny Persson, Bengt Andersson, Tore Ericsson. (2010). Relationship between autumn cold hardiness and field performance in northern Pinus sylvestris. Silva Fennica vol. 44 no. 2 article id 152. https://doi.org/10.14214/sf.152
Keywords: Scots pine; cold hardiness; genetic coefficient of variation; genetic correlation; multivariate analysis; narrow-sense heritability
Abstract | View details | Full text in PDF | Author Info
Results from 3 artificial freezing tests (one-year-old seedlings) and 15 field trials (9- to 21-year old trees) of half-sib offspring from first generation Scots pine (Pinus sylvestris L.) plus-trees were used to estimate the amount of additive genetic variance for autumn cold hardiness and traits assessed in the field, and the genetic correlations between them. Cold hardiness of individual seedlings was scored visually, based on the discoloration of their needles after freezing in a climate chamber. The field traits analyzed were tree vitality, tree height, spike knot frequency, branch diameter, branch angle, stem straightness, and susceptibility to infection by the pathogenic fungi Phacidium infestans L., Gremmeniella abietina (Lagerb.) Morelet, Melampsora pinitorqua (Braun) Rostr. and Lophodermella sulcigena (Rostr.) Höhn. Narrow sense individual heritabilities varied between 0.30 and 0.54 for autumn cold hardiness, 0 and 0.18 for tree vitality, 0.07 and 0.41 for tree height, and 0.01 and 0.26 for the remaining traits. Based on the results of the artificial freeze tests, our estimates of additive genetic correlations indicate that while early selection for cold hardiness can improve seedling survival rates in the field, it may also reduce growth in mild environments. It also has minor effects on quality traits and attack by common fungal diseases. The results indicate that artificial freeze testing is an appropriate method for identifying suitable clones for establishing seed orchards to supply stock for the reforestation of regions with harsh environments.
  • Persson, Forestry Research Institute of Sweden, Sävar, Sweden E-mail: torgny.persson@skogforsk.se (email)
  • Andersson, Forestry Research Institute of Sweden, Sävar, Sweden E-mail: ba@nn.se
  • Ericsson, Forestry Research Institute of Sweden, Sävar, Sweden E-mail: te@nn.se
article id 172, category Research article
Guntis Brumelis, Maris Strazds, Zanna Eglava. (2009). Stand structure and spatial pattern of regeneration of Pinus sylvestris in a natural treed mire in Latvia. Silva Fennica vol. 43 no. 5 article id 172. https://doi.org/10.14214/sf.172
Keywords: Pinus sylvestris; regeneration; natural forest; mire
Abstract | View details | Full text in PDF | Author Info
We examined the regeneration patterns of Pinus sylvestris L. in a natural treed mire in the hemiboreal zone in Latvia. Data on tree stem age and size was collected in 207 fine-scale plots (10 m2) and 4 medium-scale plots (400 m2). Size structure of living and dead trees was also estimated on transects 180-m and 250-m length and 10-m width. In addition, the vegetation was described in 1-m2 plots to determine preferred microsites for P. sylvestris establishment. Pinus sylvestris showed continuous regeneration by an inverse J-shaped age and size structure. Pulses of mortality induced by fire were also evident. Regeneration of P. sylvestris was mostly on Sphagnum magellanicam Brid. hummocks free of competition from Ledum palustre L. and graminoids, which were found in small interspersed patches throughout the mire. The spatial pattern of tree cohorts differed, probably due to changing moisture conditions altering seedbed conditions and by fire-induced mortality in specific areas. Recent rapid invasion by Betula pubescens Ehrh. and Picea abies (L.) Karst. in a post-fire period since 1971 is probably associated with drier conditions.
  • Brumelis, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia E-mail: guntis.brumelis@lu.lv (email)
  • Strazds, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia E-mail: ms@nn.lv
  • Eglava, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia E-mail: ze@nn.lv
article id 169, category Research article
Susanne von Bargen, Elise Grubits, Risto Jalkanen, Carmen Büttner. (2009). Cherry leaf roll virus – an emerging virus in Finland? Silva Fennica vol. 43 no. 5 article id 169. https://doi.org/10.14214/sf.169
Keywords: Betula pendula; Betula pubescens; Betula nana; IC-RT-PCR; 3' non-coding region; CLRV; phylogenetic relationship
Abstract | View details | Full text in PDF | Author Info
Cherry leaf roll virus, CLRV, is a plant pathogen that infects a variety of deciduous trees and shrubs in temperate regions. Little is known about its occurrence at high latitudes and especially in Finnish birch species. Still, symptoms that seemed to be associated with CLRV such as vein banding, leaf roll and decline have been observed in birch trees throughout the country since the summer of 2002. Six different birch species, subspecies or varieties, i.e. Betula pubescens subsp. pubescens (downy birch), B. pendula (silver birch), B. nana (dwarf birch), B. pubescens var. appressa (Kiilopää birch), B. pubescens subsp. czerepanovii (mountain birch) and B. pendula var. carelica (curly birch) originating from all over Finland were assessed by immunocapture-reverse transcription-polymerase chain reaction (IC-RT-PCR) for CLRV infection. It was shown that CLRV is widely distributed in B. pendula and B. pubescens throughout the country. Furthermore, dwarf birch, mountain birch, Kiilopää birch and curly birch were confirmed to be previously unkown hosts of CLRV. Genetic analysis of virus sequence variants originating from Finnish birch trees revealed atypical phylogenetic relationships. In contrast to CLRV isolates from birches growing in the United Kingdom and Germany which clustered exclusively within group A, Finnish CLRV isolates belonged either to group B, D or E. Thus, virus population structure in Finnish birches seems to be more variable and host plant dependency seems not to apply for Finnish CLRV isolates.
  • Bargen, Humboldt-Universität zu Berlin, Department für Nutzpflanzen- und Tierwissenschaften, Fachgebiet Phytomedizin, Lentzeallee 55/57, 14195 Berlin, Germany E-mail: susanne.von.bargen@agrar.hu-berlin.de (email)
  • Grubits, Humboldt-Universität zu Berlin, Department für Nutzpflanzen- und Tierwissenschaften, Fachgebiet Phytomedizin, Lentzeallee 55/57, 14195 Berlin, Germany E-mail: eg@nn.de
  • Jalkanen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: risto.jalkanen@metla.fi
  • Büttner, Humboldt-Universität zu Berlin, Department für Nutzpflanzen- und Tierwissenschaften, Fachgebiet Phytomedizin, Lentzeallee 55/57, 14195 Berlin, Germany E-mail: cb@nn.de
article id 168, category Research article
Saila Varis, Anne Pakkanen, Aina Galofré, Pertti Pulkkinen. (2009). The extent of south-north pollen transfer in Finnish Scots pine. Silva Fennica vol. 43 no. 5 article id 168. https://doi.org/10.14214/sf.168
Keywords: Pinus sylvestris; gene flow; adaptation; coniferous phenology; plant population biology; boreal forest dynamics
Abstract | View details | Full text in PDF | Author Info
In order to evaluate the possibility of long distance gene flow in Scots pine (Pinus sylvestris L.), we measured the amount and germinability of airborne pollen and flowering phenology in central, northern, and northernmost Finland during 1997–2000. Totally 2.3% of the detected germinable pollen grains were in the air prior to local pollen shedding. The mean number of germinable pollen grains m–3 air per day was lower prior to local pollen shedding, but in the year 2000 there were more germinable pollen grains in the air of central study site prior to local pollen shedding. Prior to the onset of pollen shedding, 7.5% of female strobili which we observed were receptive. On average female strobili became receptive three days earlier than local pollen shedding started. During the period of pollen shedding in the central study site, we detected germinable airborne pollen in the northern site in years 1997, 1999 and 2000. At the northermost site, we detected germinable airborne pollen during the pollen-shedding period of the northern site in 2000. Our detection of germinable airborne pollen and synchrony of strobili maturation from south to north suggest that populations of Scots pine in central and northern Finland may provide genetic material to populations in northern and northernmost Finland, respectively.
  • Varis, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: saila.varis@metla.fi (email)
  • Pakkanen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: ap@nn.fi
  • Galofré, Passeig de l’estació 21, 5-1, 43800 Valls, Tarragona, Spain E-mail: ag@nn.fi
  • Pulkkinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Karkkilantie 247, FI-12600 Läyliäinen, Finland E-mail: pp@nn.fi
article id 181, category Research article
Jari Miina, Juha-Pekka Hotanen, Kauko Salo. (2009). Modelling the abundance and temporal variation in the production of bilberry (Vaccinium myrtillus L.) in Finnish mineral soil forests. Silva Fennica vol. 43 no. 4 article id 181. https://doi.org/10.14214/sf.181
Keywords: vegetation; generalized linear mixed model; heath forest
Abstract | View details | Full text in PDF | Author Info
  • Miina, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jari.miina@metla.fi (email)
  • Hotanen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jph@nn.fi
  • Salo, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: ks@nn.fi
article id 193, category Research article
Jaume Gort, Ane Zubizarreta Gerendiain, Heli Peltola, Pertti Pulkkinen, Johanna Routa, Raimo Jaatinen. (2009). Differences in fibre properties in Scots pine (Pinus sylvestris L.) genetic entries grown at different spacing and sites. Silva Fennica vol. 43 no. 3 article id 193. https://doi.org/10.14214/sf.193
Keywords: fibre length; fibre width; genetic entry; growth; wood density; coarseness; spacing
Abstract | View details | Full text in PDF | Author Info
In forest breeding, stem volume growth and sawn timber quality indicators have been used as the most important selection traits for Scots pine, whereas less attention has been given to characteristics such as fibre properties. In the above context, we investigated the differences in fibre properties (i.e. fibre length, fibre width and coarseness) in 20 year old Scots pine (Pinus sylvestris L.) genetic entries as affected by spacing and site, but also the phenotypic correlations between fibre properties, yield and wood density. The study was based on materials harvested from 10 genetic entries grown in a spacing trial (site 1) in central Finland, with a current stand density of 2000 (spacing 1), 2000–2500 (spacing 2) and 4000 trees/ha (spacing 3). In order to study the effects of site, we harvested additional material (4 of 7 genetic entries same as on site 1) from a trial located in southern Finland with a corresponding stand density of 2000 trees/ha (site 2). On site 1, spacing 1 and 3, all average values for analysed fibre properties were similar. In spacing 2 average values were slightly higher. On site 2, the average values for different fibre properties were similar compared to the corresponding spacing 1 on site 1. Spacing affected (p < 0.05) all average fibre properties on site 1; as did also site, when comparing same genetic entries grown on both sites. Regardless of spacing and site, the phenotypic correlations between average fibre length, fibre width and coarseness showed, on average, moderate to strong correlation (p < 0.05). Fibre width showed, in general, low and positive phenotypic correlation with diameter at breast height, stem volume and wood density on site 1. However, as a whole, the ranking of genetic entries changed depending on the trait and spacing considered. Thus, no overall ranking between genetic entries was possible.
  • Gort, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: jaume.gort@joensuu.fi (email)
  • Zubizarreta Gerendiain, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: azg@nn.fi
  • Peltola, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: hp@nn.fi
  • Pulkkinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Karkkilantie E-mail: pp@nn.fi
  • Routa, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: jr@nn.fi
  • Jaatinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Karkkilantie E-mail: rj@nn.fi
article id 192, category Research article
Heli Peltola, Jaume Gort, Pertti Pulkkinen, Ane Zubizarreta Gerendiain, Jouni Karppinen, Veli-Pekka Ikonen. (2009). Differences in growth and wood density traits in Scots pine (Pinus sylvestris L.) genetic entries grown at different spacing and sites. Silva Fennica vol. 43 no. 3 article id 192. https://doi.org/10.14214/sf.192
Keywords: genetic entry; stem volume; height; diameter; wood property traits; phenotypic correlation
Abstract | View details | Full text in PDF | Author Info
In forest breeding, stem volume has typically taken as the most important selection trait, whereas less attention has been given to wood density traits. In this work, we investigated the effects of spacing and genetic entry on the growth, yield and wood density traits in 20 year old Scots pines (Pinus sylvestris L.) based on 10 genetic entries harvested from a spacing trial (stand density range 2000–4000 trees/ha) in central Finland. In order to study also the site effects, we harvested additional material from a trial located in southern Finland (stand density of 2000 trees/ha). Compared to growth and yield properties, wood density traits showed a lower phenotypic variation. Phenotypic correlations among different traits were negative, and mostly moderate to high, suggesting that selection for one trait would simultaneously affect the others. In addition, moderate to strong phenotypic correlations were found among different wood density traits. Stem volume (V) and breast height diameter (DBH) were the largest in widest spacing, whereas in the densest one tree height (H) and latewood percentage were the highest. Genetic entry affected H and wood density traits regardless of spacing. When comparing two sites (with same stand density), genetic entry affected H, whereas site affected DBH and wood density traits. Ranking between genetic entries changed depending on the trait, spacing or site considered. Therefore, no overall ranking was possible. However, we could identify genetic entries having a high V and a relatively high wood density, showing potential for future forest regeneration material.
  • Peltola, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: heli.peltola@joensuu.fi (email)
  • Gort, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: jg@nn.fi
  • Pulkkinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Karkkilantie 247, FI-12600 Läyliäinen, Finland E-mail: pp@nn.fi
  • Zubizarreta Gerendiain, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: azg@nn.fi
  • Karppinen, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: jk@nn.fi
  • Ikonen, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: vpi@nn.fi
article id 191, category Research article
Katri Luostarinen, Noora Huotari, Eila Tillman-Sutela. (2009). Effect of regeneration method on growth, wood density and fibre properties of downy birch (Betula pubescens Ehrh.). Silva Fennica vol. 43 no. 3 article id 191. https://doi.org/10.14214/sf.191
Keywords: coppice; fibre length; fibre width; regeneration methods; wood properties
Abstract | View details | Full text in PDF | Author Info
Short rotation tree stands, established by coppicing, are nowadays used mainly for energy purposes in Fennoscandia, but their usage for pulp raw material may increase in the future. Downy birch (Betula pubescens), which is commonly used for pulp production in boreal zone, has good sprouting capacity. However, it is not known if the fibre properties of sprout-originated downy birches differ from those of seed-originated ones. Therefore, fibre length and width of sprout- and seed-originated downy birches grown on fertile soil were measured at a stand age of 25 years. Additionally annual ring width, stem height and diameter, and wood density were studied to compare the growth and wood properties of sprout- and seed-originated birches. Annual rings were slightly wider in sprout- than in seed-originated birches, whereas no differences were observed in wood density. Fibres, too, were slightly longer and wider in sprout- than in seed-originated trees. Still these minor differences observed here are hardly significant for the industries using birch wood. Consequently downy birch wood from coppiced stands is well suited for pulp. The advantages of coppice, i.e. rapidity and low costs of establishment, productivity, and the ability of downy birch to grow on untypical forest sites, may even increase the importance of the wood coming from coppiced birch stands in the future.
  • Luostarinen, Faculty of Forest Sciences, University of Joensuu, P.O. Box 111, FI-80101, Joensuu, Finland E-mail: katri.luostarinen@joensuu.fi (email)
  • Huotari, Finnish Forest Research Institute, Muhos Research Unit, Kirkkosaarentie, FI-91500 Muhos, Finland E-mail: nh@nn.fi
  • Tillman-Sutela, Finnish Forest Research Institute, Muhos Research Unit, Kirkkosaarentie, FI-91500 Muhos, Finland E-mail: ets@nn.fi
article id 205, category Research article
Pekka Vakkari, Mari Rusanen, Katri Kärkkäinen. (2009). High genetic differentiation in marginal populations of European white elm (Ulmus laevis). Silva Fennica vol. 43 no. 2 article id 205. https://doi.org/10.14214/sf.205
Keywords: marginal populations; genetic differentiation; genetic conservation; Ulmus
Abstract | View details | Full text in PDF | Author Info
Studies on the amount of genetic variation in marginal populations and differentiation between them are essential for assessment of best gene conservation strategies and sampling schemes. Thirteen marginal populations of Ulmus laevis in southern Finland and one in Estonia were investigated for genetic variation in 20 allozyme loci. Population differentiation among Finnish stands was high, Fst = 0.290, and mean genetic diversity low, He = 0.088. The differentiation follows the isolation-by-distance structure within the core of the distribution area (lake Vanajavesi). Fairly high frequency of recurrent genotypes was observed, but this did not have an influence on the genetic parameters. The observed genetic structure is consistent with the central-marginal hypothesis. In the light of the results, the Finnish gene conservation strategy for U. laevis seems to be on a sound basis.
  • Vakkari, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: pekka.vakkari@metla.fi (email)
  • Rusanen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: mr@nn.fi
  • Kärkkäinen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: kk@nn.fi
article id 217, category Research article
Ville Kankaanhuhta, Timo Saksa, Heikki Smolander. (2009). Variation in the results of Norway spruce planting and Scots pine direct seeding in privately-owned forests in southern Finland. Silva Fennica vol. 43 no. 1 article id 217. https://doi.org/10.14214/sf.217
Keywords: Pinus sylvestris; Picea abies; quality control; forest regeneration survey; forest regeneration inventory; quality management
Abstract | View details | Full text in PDF | Author Info
This study describes the variation in the planting results for 3-year-old Norway spruce (Picea abies (L.) Karst.) and 4-year-old Scots pine (Pinus sylvestris L.) using direct seeding in privately-owned regeneration areas in southern Finland. The study material consists of operative forest regeneration quality management inventory areas from the years 2000–2006. The effect of both the regional and the administrative levels as well as ecological factors was modelled on the basis of the hierarchy structure forestry centre, Forest Owners’ Association (= FOA), forestry professional, regeneration area and sample plot. The major part of the variation occurred at the sample plot and regeneration area level. Particular attention was paid to observation of the clustered spatial distribution of Scots pine seedlings. The FOA and forestry professional levels explained 5% of the variation in Norway spruce planting and 11% of the variation in Scots pine direct seeding. Applied forest regeneration operations, site and soil characteristics were included in the fixed effects. In the planting of Norway spruce the most important factor explaining the regeneration result was soil preparation. Mounding produced better results than patching and disc trenching. The site and soil characteristics were other important factors in the operations. The selection of direct seeding of Scots pine on too fertile, fine textured or moist sites yielded poor results.
  • Kankaanhuhta, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: ville.kankaanhuhta@metla.fi (email)
  • Saksa, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: ts@nn.fi
  • Smolander, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: hs@nn.fi
article id 466, category Research article
Ilkka Korpela, Tuukka Tuomola, Timo Tokola, Bo Dahlin. (2008). Appraisal of seedling stand vegetation with airborne imagery and discrete-return LiDAR – an exploratory analysis. Silva Fennica vol. 42 no. 5 article id 466. https://doi.org/10.14214/sf.466
Keywords: silviculture; remote sensing; forest regeneration; classification; species
Abstract | View details | Full text in PDF | Author Info
The potential for combined use of airborne discrete-return LiDAR and digital imagery in the classification and measurement of common seedling stand vegetation was examined in southern Finland (61°50’N, 24°20’E). Classification was based on spectral and textural image features in addition to geometric and radiometric features of the LiDAR. The accuracy of leaf-on, LiDAR-based terrain elevation models was tested as well as the accuracy of LiDAR in the measurement of vegetation heights. LiDAR-based canopy height and the range-normalized intensity of the LiDAR were strong explanatory variables in vegetation classification. Interspecies variation was observed in the height measurement accuracy of LiDAR for different tree, shrub and low vegetation canopies. Elevation models derived with 1–15 pulses per m2 showed an inherent noise of app. 15–25 cm, which restricts the use of LiDAR in regeneration assessment of very young stands. The spatial pattern of the competing vegetation was reproduced in classification-based raster surfaces, which could be useful in deriving meaningful treatment proposals.
  • Korpela, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland E-mail: ilkka.korpela@helsinki.fi (email)
  • Tuomola, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland E-mail: tt@nn.fi
  • Tokola, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland E-mail: tt@nn.fi
  • Dahlin, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland E-mail: bd@nn.fi
article id 229, category Research article
Carmen Martín, Teresa Parra, Margarita Clemente-Muñoz, Esteban Hernández-Bermejo. (2008). Genetic diversity and structure of the endangered Betula pendula subsp. fontqueri populations in the south of Spain. Silva Fennica vol. 42 no. 4 article id 229. https://doi.org/10.14214/sf.229
Keywords: Betula pendula; B. pendula subsp. fontqueri; genetic diversity; population; RAPD
Abstract | View details | Full text in PDF | Author Info
Betula pendula subsp. fontqueri, present in the south of Spain, has been considered in danger of extinction and, for this reason, some regional governments in Spain have included their populations in conservation programmes. In order to establish the genetic structure of the Betula pendula subsp. fontqueri populations, a random amplified polymorphic DNA (RAPD) analysis was carried out. Two B. pubescens populations were included in the study as taxonomic controls. B. pendula subsp. fontqueri populations were clearly differentiated through UPGMA, and showed significant pairwise genetic distance (ΦST) values between all pairs of populations obtained by AMOVA. Genetic diversity found between populations was not correlated to geographical distances. The significant differences among populations must be due to progressive isolation of Betula populations along their paleogeographical history, and more recently to the drastic fragmentation and reduction of some of these populations. The results obtained in this work show clear genetic differences which could be considered in the management of conservation strategies for Betula pendula subsp. fontqueri in its Iberian meridional distribution.
  • Martín, Departamento de Biología Vegetal, Escuela Técnica Superior de Ingenieros Agrónomos de Madrid, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040-Madrid, Spain E-mail: mariacarmen.martin@upm.es (email)
  • Parra, Departamento de Ciencias y Recursos Agrícolas y Forestales, Universidad de Córdoba, Avda. Linneo s/n, 14004-Córdoba, Spain E-mail: tp@nn.es
  • Clemente-Muñoz, Departamento de Ciencias y Recursos Agrícolas y Forestales, Universidad de Córdoba, Avda. Linneo s/n, 14004-Córdoba, Spain E-mail: mcm@nn.es
  • Hernández-Bermejo, Departamento de Ciencias y Recursos Agrícolas y Forestales, Universidad de Córdoba, Avda. Linneo s/n, 14004-Córdoba, Spain E-mail: ehb@nn.es
article id 250, category Research article
Saara Lilja-Rothsten, Michelle de Chantal, Chris Peterson, Timo Kuuluvainen, Ilkka Vanha-Majamaa, Pasi Puttonen. (2008). Microsites before and after restoration in managed Picea abies stands in southern Finland: effects of fire and partial cutting with dead wood creation. Silva Fennica vol. 42 no. 2 article id 250. https://doi.org/10.14214/sf.250
Keywords: biodiversity; boreal forest; regeneration; coarse woody debris; disturbance dynamics; CWD; managed forest
Abstract | View details | Full text in PDF | Author Info
Different types of microsites, e.g. CWD (coarse woody debris), mounds, and uprooting pits, are important for tree regeneration and biodiversity. However, microsite diversity is greatly reduced in managed stands. We studied how restoration treatments changed microsite distribution in mature managed Picea abies stands. Four cutting treatments were used: uncut, low-CWD (5 m3 ha–1 of down retention trees, DRT, and 50 m3 ha–1 of standing retention trees), intermediate-CWD (as previous but leaving 30 m3 ha–1 of DRT), and high-CWD (as previous but with 60 m3 ha–1 of DRT). Timber harvested from stands ranged from 108–168 m3 ha–1. Half of the stands were burned, and half remained unburned. Sampling was stratified into upland and paludified biotopes within each stand. The pre-treatment microsite distributions were dominated by level ground in both biotopes; mounds and microsites on or next to CWD or a stump were slightly more abundant in the paludified than in the upland biotopes. Microsites were more diverse after cutting, with and without fire. The cutting treatment increased the relative abundances of microsites on or next to CWD. Fire consumed small diameter dead wood and flattened mounds. Microsites were more diverse in paludified than in upland biotopes. The results demonstrate that microsite diversity can rapidly be restored to structurally impoverished managed Picea stands despite a large portion of wood volume being harvested.
  • Lilja-Rothsten, University of Helsinki, Dept. of Forest Ecology, Finland E-mail: saara.lilja@helsinki.fi (email)
  • Chantal, University of Helsinki, Dept. of Forest Ecology, Finland E-mail: mdc@nn.fi
  • Peterson, Dept. of Plant Biology, University of Georgia, Athens, GA, USA E-mail: cp@nn.us
  • Kuuluvainen, University of Helsinki, Dept. of Forest Ecology, Finland E-mail: tk@nn.fi
  • Vanha-Majamaa, The Finnish Forest Research Institute, Vantaa Unit, Finland E-mail: ivm@nn.fi
  • Puttonen, The Finnish Forest Research Institute, Vantaa Unit, Finland E-mail: pp@nn.fi
article id 299, category Research article
Hongcheng Zeng, Timo Pukkala, Heli Peltola, Seppo Kellomäki. (2007). Application of ant colony optimization for the risk management of wind damage in forest planning. Silva Fennica vol. 41 no. 2 article id 299. https://doi.org/10.14214/sf.299
Keywords: harvest scheduling; heuristics; genetic algorithms; simulated annealing; spatial optimization
Abstract | View details | Full text in PDF | Author Info
Ant colony optimization (ACO) is still quite a new technique and seldom used in the field of forest planning compared to other heuristics such as simulated annealing and genetic algorithms. This work was aimed at evaluating the suitability of ACO for optimizing the clear-cut patterns of a forest landscape when aiming at simultaneously minimizing the risk of wind damage and maintaining sustainable and even flow of periodical harvests. For this purpose, the ACO was first revised and the algorithm was coded using the Visual Basic Application of the ArcGIS software. Thereafter, the performance of the modified ACO was demonstrated in a forest located in central Finland using a 30-year planning period. Its performance was compared to simulated annealing and a genetic algorithm. The revised ACO performed logically since the objective function value was improving and the algorithm was converging during the optimization process. The solutions maintained a quite even periodical harvesting timber while minimizing the risk of wind damage. Implementing the solution would result in smooth landscape in terms of stand height after the 30-year planning period. The algorithm is quite sensitive to the parameters controlling pheromone updating and schedule selecting. It is comparable in solution quality to simulated annealing and genetic algorithms.
  • Zeng, University of Joensuu, Faculty of Forest Sciences, P. O. Box 111, FI-80101 Joensuu, Finland E-mail: hongcheng.zeng@joensuu.fi (email)
  • Pukkala, University of Joensuu, Faculty of Forest Sciences, P. O. Box 111, FI-80101 Joensuu, Finland E-mail: tp@nn.fi
  • Peltola, University of Joensuu, Faculty of Forest Sciences, P. O. Box 111, FI-80101 Joensuu, Finland E-mail: hp@nn.fi
  • Kellomäki, University of Joensuu, Faculty of Forest Sciences, P. O. Box 111, FI-80101 Joensuu, Finland E-mail: sk@nn.fi
article id 291, category Research article
Yildiray Lise, Zeki Kaya, Fikret Isik, Rumi Sabuncu, Irfan Kandemir, Sertaç Önde. (2007). The impact of over-exploitation on the genetic structure of Turkish red pine (Pinus brutia Ten.) populations determined by RAPD markers. Silva Fennica vol. 41 no. 2 article id 291. https://doi.org/10.14214/sf.291
Keywords: Pinus brutia Ten.; RAPD-PCR; human over-exploitation; genetic structure; inbreeding
Abstract | View details | Full text in PDF | Author Info
To determine the possible impact of over-exploitation on the genetic structure of Turkish red pine (Pinus brutia Ten.) populations, three natural and three over-exploited (human degraded) populations of the species in the Mediterranean region of Turkey were investigated with Randomly Amplified Polymorphic DNA (RAPD). With the 80 RAPD primers tested, 12 of them yielded 137 polymorphic RAPD fragments. Four of the studied populations maintained unique fragments. The mean proportion of polymorphic fragments for all populations ranged from 89.8 to 98.9% and there were no significant differences between natural (94.8%) vs. over-exploited populations (92.7%). The estimated heterozygosity values suggested that Turkish red pine maintains high levels of genetic diversity (range 0.24–0.28) though studied populations and grouped ones as natural (He = 0.28) vs. over-exploited (0.27) did not differ significantly. The mean FST value indicated that the large portion of the total genetic diversity was within populations (93%), but this value was lower in the natural populations (92%) than in the over-exploited ones (94%). In over-exploited populations, excess of homozygosity was observed (about 6% higher) as compared to natural populations, indicating impacts of inbreeding in P. brutia.
  • Lise, Department of Biological Sciences, Middle East Technical University, 06531, Ankara, Turkey E-mail: yl@nn.tr
  • Kaya, Department of Biological Sciences, Middle East Technical University, 06531, Ankara, Turkey E-mail: kayaz@metu.edu.tr (email)
  • Isik, North Carolina State University, Raleigh, USA E-mail: fi@nn.us
  • Sabuncu, Southwest Anatolia Forest Research Institute, Antalya, Turkey E-mail: rs@nn.tr
  • Kandemir, Department of Biology, Zonguldak Karaelmas University, 67100, Zonguldak, Turkey E-mail: ik@nn.tr
  • Önde, Department of Biological Sciences, Middle East Technical University, 06531, Ankara, Turkey E-mail: so@nn.tr
article id 308, category Research article
Ville Hallikainen, Mikko Hyppönen, Juha Hyvönen, Juhani Niemelä. (2007). Establishment and height development of harvested and naturally regenerated Scots pine near the timberline in North-East Finnish Lapland. Silva Fennica vol. 41 no. 1 article id 308. https://doi.org/10.14214/sf.308
Keywords: natural regeneration; seedling establishment; Scots pine; timberline; seed-tree method; density model; height development model
Abstract | View details | Full text in PDF | Author Info
Researchers and professionals in practical forestry have faced problems concerning the regeneration success of Scots pine in natural regeneration near the timberline in North-East Lapland. The aim of the study was to analyze the seedling establishment and seedling height development of Scots pine in seed-tree stands in the area. The average number of living pine seedlings in the study stands was about 1000 ha–1, but there was considerable variation between the stands. The seedling density was modelled using a multinomial logistic regression with a random factor. Forest site type and the time since seed-tree cutting were the most significant explanatory variables in the model. The probability of reaching the acceptable seedling density was higher on dry site types than on the more fertile ones. The probability increased with the time elapsed since the regeneration activities. Effective temperature sum and the number of intermediate pines also positively affected the probability, but the presence of residual trees negatively. On northern and eastern slopes the probability was lower than on southern and western ones. Seedling height was modelled using a linear mixed model. The age of a dominant seedling was the most positively effective explanatory variable in the height development model. Other positively affecting significant predictors were time since seed-tree cutting, number of intermediate birches, and distance between a seedling and the nearest seed tree. Degree of paludification had a negative effect. The study suggests that the regeneration of Scots pine in North-East Lapland is a relatively slow process.
  • Hallikainen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: ville.hallikainen@metla.fi (email)
  • Hyppönen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: mikko.hypponen@metla.fi
  • Hyvönen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: juha.hyvonen@metla.fi
  • Niemelä, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: jn@nn.fi
article id 304, category Research article
Joanna Kosinska, Andrzej Lewandowski, Wladyslaw Chalupka. (2007). Genetic variability of Scots pine maternal populations and their progenies. Silva Fennica vol. 41 no. 1 article id 304. https://doi.org/10.14214/sf.304
Keywords: Pinus sylvestris L.; genetic variation; allozymes; gene conservation
Abstract | View details | Full text in PDF | Author Info
The genetic variability of Scots pine was investigated in six populations from Poland representing two maternal populations and their natural and artificial progenies. Thirteen enzyme systems controlled by 25 allozyme loci were analyzed using starch gel electrophoresis. Progeny populations maintained a high and similar level of genetic variation to that observed in the maternal populations. As expected, much closer genetic relationships were observed between maternal populations and their respective progeny than between the two maternal populations themselves. Progeny populations had the same major alleles, but differed in the number of rare alleles. Therefore, probably not all rare alleles were transferred from the maternal stands to the progenies. In addition, new rare alleles appeared in the progeny populations, possibly as a result of external pollen flow into the maternal populations.
  • Kosinska, Department of Human Medical Genetics, Medical University of Warsaw, Oczki 1, 02-007 Warsaw, Poland E-mail: jk@nn.pl
  • Lewandowski, Polish Academy of Sciences, Institute of Dendrology, 62-035 Kórnik, Poland E-mail: al@nn.pl (email)
  • Chalupka, Polish Academy of Sciences, Institute of Dendrology, 62-035 Kórnik, Poland E-mail: wc@nn.pl
article id 319, category Research article
Ulises Diéguez-Aranda, José Antonio Grandas-Arias, Juan Gabriel Álvarez-González, Klaus von Gadow. (2006). Site quality curves for birch stands in north-western Spain. Silva Fennica vol. 40 no. 4 article id 319. https://doi.org/10.14214/sf.319
Keywords: site quality; Betula pubescens; generalized algebraic difference approach; base-age invariant dynamic equation; Hossfeld model; Galicia
Abstract | View details | Full text in PDF | Author Info
A model for predicting the height growth of even-aged, birch (Betula pubescens Ehrh.) dominated stands in Galicia (north-western Spain) was developed. Data from stem analysis of 214 trees were used for model construction. Two dynamic site equations derived with the generalized algebraic difference approach (GADA) were tested, which combine compatible site index and height models in one common equation. Both equations are base-age invariant and directly estimate height and site index from any height and age. The fittings were done in one stage using the base-age-invariant dummy variables method. A second-order continuous-time autoregressive error structure was used to correct the inherent autocorrelation of the longitudinal data used in this study. Cieszewski’s model best described the data. This model is therefore recommended for height growth prediction and site classification of birch stands in Galicia.
  • Diéguez-Aranda, Departamento de Ingeniería Agroforestal, Universidad de Santiago de Compostela. Escuela Politécnica Superior, Campus universitario, 27002 Lugo, Spain E-mail: udieguez@lugo.usc.es (email)
  • Grandas-Arias, Departamento de Ingeniería Agroforestal, Universidad de Santiago de Compostela. Escuela Politécnica Superior, Campus universitario, 27002 Lugo, Spain E-mail: jaga@nn.es
  • Álvarez-González, Departamento de Ingeniería Agroforestal, Universidad de Santiago de Compostela. Escuela Politécnica Superior, Campus universitario, 27002 Lugo, Spain E-mail: jgag@nn.es
  • Gadow, Institut fur Waldinventur und Waldwachstum, George-Auguts-Universität Göttingen. Büsgenweg 5, D-37077 Göttingen, Germany E-mail: kg@nn.de
article id 314, category Research article
Yuhua Wang, Helena Korpelainen, Chunyang Li. (2006). Microsatellite polymorphism in the edaphic spruce, Picea asperata, originating from the mountains of China. Silva Fennica vol. 40 no. 4 article id 314. https://doi.org/10.14214/sf.314
Keywords: genetic diversity; microsatellite polymorphism; micro-geographic differentiation; natural selection; mutation
Abstract | View details | Full text in PDF | Author Info
Microsatellite variation of Picea asperata Mast. originating from the mountains of China was investigated by analyzing variation at seven SSR loci in 250 individuals representing ten populations. A fair degree of genetic diversity and considerable population subdivision occurred with the mean gene diversity (H) of 0.707, and genetic distances among populations varying between 0.121 and 0.224 (FST) and between 0.100 and 0.537 (RST). However, inter-population genetic distances showed no correlation with geographic distances between the population sites. This ruled out a simple isolation by distance model and suggested that migration does not have a great impact. In fact, the amount of gene flow, detected using private alleles, was very low, equaling only 0.753. Allele permutation tests revealed that stepwise-like mutations, coupled with genetic drift, could contribute to population differentiation. Moreover, significant genetic differences between populations were detected at most loci. The results indicate that natural selection, presumably through environmental stress, may be one of the main factors causing micro-geographical differentiation in the genetic structure of P. asperata. Based on SSR genotypes, 70% of the 250 individuals were correctly classified into their sites of origin. This suggests that microsatellites (SSRs) are effective in distinguishing genotypes of P. asperata originating from diverse eco-geographical sites in China.
  • Wang, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, China E-mail: yw@nn.cn
  • Korpelainen, Department of Applied Biology, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: hk@nn.fi
  • Li, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, China E-mail: licy@cib.ac.cn (email)
article id 476, category Research article
Ignazio Monteleone, Diana Ferrazzini, Piero Belletti. (2006). Effectiveness of neutral RAPD markers to detect genetic divergence between the subspecies uncinata and mugo of Pinus mugo Turra. Silva Fennica vol. 40 no. 3 article id 476. https://doi.org/10.14214/sf.476
Keywords: molecular markers; population differentiation; genetic diversity; Pinus mugo; mountain pine; dwarf mountain pine
Abstract | View details | Full text in PDF | Author Info
Fifteen populations of Pinus mugo subsp. mugo (shrub) and Pinus mugo subsp. uncinata (erect), located in the Alps, were investigated through genetic variation scored at 64 polymorphic RAPD loci. In addition, morphological traits of the female cones were analysed. According to AMOVA most of the genetic variation was found within populations (83.39%), and only 1.25% of it between subspecies. Populations differed in terms of their internal genetic variation, with Nei’s gene diversity ranging from 0.227 to 0.397. Morphological data showed differences between subspecies, although none of the populations showed full accordance with expectations. Significant correlation was found between matrices for geographical and morphological distances, while genetic distances were not correlated with any other aspect. The efficacy of morphological and RAPD markers in discriminating between subspecies, and the contribution of the results in relation to the preservation of biodiversity, are discussed.
  • Monteleone, DI.VA.P.R.A., Plant Genetics and Breeding, University of Turin, via Leonardo da Vinci 44, I-10095 Grugliasco, Italy E-mail: im@nn.it
  • Ferrazzini, DI.VA.P.R.A., Plant Genetics and Breeding, University of Turin, via Leonardo da Vinci 44, I-10095 Grugliasco, Italy E-mail: df@nn.it
  • Belletti, DI.VA.P.R.A., Plant Genetics and Breeding, University of Turin, via Leonardo da Vinci 44, I-10095 Grugliasco, Italy E-mail: piero.belletti@unito.it (email)
article id 329, category Research article
Vesa Juntunen, Seppo Neuvonen. (2006). Natural regeneration of Scots pine and Norway spruce close to the timberline in northern Finland. Silva Fennica vol. 40 no. 3 article id 329. https://doi.org/10.14214/sf.329
Keywords: Norway spruce; regeneration; Scots pine; timberline; tree line; seed maturity; seedling mortality
Abstract | View details | Full text in PDF | Author Info
Two different datasets were analyzed in order to clarify the factors that affect regeneration success of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) in the climatically extreme areas in northern Finland. First, pine seed maturity and the number of cones in the trees were investigated at five pairs of study sites during the period 1997–2003. Secondly, the rate of seedling establishment and seedling survival of Scots pine and Norway spruce were monitored and compared among three different timberline zones (forest zone, timberline, tree line) in 13 localities during the period 1983–1999. The first study showed that both cone production (bud formation) and seed maturity may be limiting factors for successful reproduction in the climatically marginal habitats. Seed maturity correlated well with the temperature sum of the summer, but variation in the number of cones had a periodic component rather than strictly following the temperature sum of the summer of bud formation. Monitoring surveys since 1983 showed that pine and spruce regenerated more or less regularly in all the zones during 1983–1999. However, seedling mortality of pines was much higher compared to spruce. In general, initially small sized seedlings showed higher mortality compared with larger ones. The results suggest that besides restrictions in reproduction, stand dynamics in the timberline habitats are strongly controlled by seedling mortality due to a variety of causes.
  • Juntunen, Finnish Forest Research Institute, Kolari Research Unit, Muoniontie 21, FI-95900 Kolari, Finland E-mail: vesa.juntunen@metla.fi (email)
  • Neuvonen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: sn@nn.fi
article id 326, category Research article
Xuejiang Zhang, Helena Korpelainen, Chunyang Li. (2006). Microsatellite variation of Quercus aquifolioides populations at varying altitudes in the Wolong Natural Reserve of China. Silva Fennica vol. 40 no. 3 article id 326. https://doi.org/10.14214/sf.326
Keywords: genetic differentiation; genetic variation; altitudinal gradients; microsatellites; Quercus aquifolioides
Abstract | View details | Full text in PDF | Author Info
Genetic variation and differentiation were investigated among five natural populations of Quercus aquifolioides occurring along an altitudinal gradient that varied from 2000 to 3600 m above sea level in the Wolong Natural Reserve of China, by analyzing variation at six microsatellite loci. The results showed that the populations were characterized by relatively high intra-population variation with the average number of alleles equaling 11.33 per locus and the average expected heterozygosity (HE) being 0.779. The amount of genetic variation varied only little among populations, which suggests that the influence of altitude factors on microsatellite variation is limited. However, there is a significantly positive correlation between altitude and the number of low-frequency alleles (R2 = 0.97, P < 0.01), which indicates that Q. aquifolioides from high altitudes has more unique variation, possibly enabling adaptation to severe conditions. F statistics showed the presence of a slight deficiency of heterozygosity (FIS = 0.136) and a low level of differentiation among populations (FST = 0.066). The result of the cluster analysis demonstrated that the grouping of populations does not correspond to the altitude of the populations. Based on the available data, it is likely that the selective forces related to altitude are not strong enough to significantly differentiate the populations of Q. aquifolioides in terms of microsatellite variation.
  • Zhang, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, P. R. China E-mail: xz@nn.cn (email)
  • Korpelainen, Department of Applied Biology, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: hk@nn.fi
  • Li, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China E-mail: licy@cib.ac.cn
article id 359, category Research article
Paula Horne. (2006). Forest owners’ acceptance of incentive based policy instruments in forest biodiversity conservation – a choice experiment based approach. Silva Fennica vol. 40 no. 1 article id 359. https://doi.org/10.14214/sf.359
Keywords: forest owners; heterogeneity; incentive based policy mechanism; choice experiment method
Abstract | View details | Full text in PDF | Author Info
Finland has launched a new policy programme (METSO) to enhance conservation of forest biodiversity. In non-industrial private forests, the policy is based on economic incentives and voluntarism on the part of forest owners. While biodiversity conservation is the main target of the policy, social acceptability is considered to be of great importance. This study examined the factors that affect the acceptability of biodiversity conservation contracts among private forest owners, and the amount of compensation needed to keep the forest owners at least as well off as before the contract. Choice experiment method was used to analyse the data that were collected by surveying 3000 Finnish private forest owners. Analysing separately those respondents who were willing to enter into a conservation contract allowed an assessment of the impact of forest owners’ heterogeneity on compensation amount. The results show how the welfare of forest owners shifts when the contract terms are changed. In a base scenario the forest owner was assumed to be the initiator of the contract that would require only small patches of forest to be protected, and would also bind new forest owners over its duration of ten years. For all respondents, the average demand for compensation would be around 224 euros annually. When those always choosing the “no additional conservation” alternative were excluded, the average welfare impact of the base scenario was positive.
  • Horne, Finnish Forest Research Institute, Unioninkatu 40 A, FI-00170 Helsinki, Finland E-mail: paula.horne@metla.fi (email)
article id 376, category Research article
Nils Lexerød, Trond Eid. (2005). Recruitment models for Norway spruce, Scots pine, birch and other broadleaves in young growth forests in Norway. Silva Fennica vol. 39 no. 3 article id 376. https://doi.org/10.14214/sf.376
Keywords: regeneration; national forest inventories; growth simulators; probability models; conditional models; Norway
Abstract | View details | Full text in PDF | Author Info
The objective of the present study was to develop recruitment models for Norway spruce, Scots pine, birch and other broadleaves in young growth forests in Norway. The models were developed from permanent sample plots established by the National Forest Inventory, and they will be included in a growth simulator that is part of a large-scale forestry scenario model. The modelling was therefore restricted to independent variables directly or indirectly available from inventories for practical forest management planning. A two-stage modelling approach that suited the stochastic nature of recruitment in boreal forests was used. Models predicting the probability of recruitment were estimated in a first stage, and conditional models for the number of recruits were developed in a second. The probability models as well as the conditional models were biologically realistic and logical. The goodness of fit tests revealed that the probability models fitted the data well, while the coefficients of determination for the conditional models were relatively low. No independent test data were available, but comparisons of predicted and observed number of recruits in different sub-groups of the data revealed few large deviations. The high level of large random errors was probably due to the great variability observed in number of recruits rather than inappropriate specifications of the models. Provided the generally high level of uncertainty connected to analysis performed with large-scale forestry scenario models and the stochastic nature of recruitment, the presented models seem to give satisfactory levels of accuracy.
  • Lexerød, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway E-mail: nils.lexerod@umb.no (email)
  • Eid, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway. E-mail nils.lexerod@umb.no E-mail: te@nn.no
article id 372, category Research article
Ulf Sikström. (2005). Pre-harvest soil acidification, liming or N fertilization did not significantly affect the survival and growth of young Norway spruce. Silva Fennica vol. 39 no. 3 article id 372. https://doi.org/10.14214/sf.372
Keywords: Picea abies; regeneration; limestone; sulphur powder; urea
Abstract | View details | Full text in PDF | Author Info
Acidification, liming, and N fertilization affect a number of soil properties. Such changes may have an impact on forest regeneration and yield. The aim of this study was to investigate the survival and growth of Picea abies (L.) Karst. planted on plots that had been acidified (in 12 annual treatments totalling 600 or 1200 kg S ha–1 in the form of elemental sulphur), limed (12 x 500 = 6000 kg lime ha–1 in the form of CaCO3) or N-fertilized (3 x 200 = 600 kg N ha–1 in the form of urea) prior to harvest. Trees growing on plots treated with a combination of the N plus the lower S application were also tested. None of the treatments, applied in three replicate stands, significantly influenced either survival or growth of Picea abies trees during the first 11 growing seasons after planting.
  • Sikström, SkogForsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: ulf.sikstrom@skogforsk.se (email)
article id 381, category Research article
Jianxun Luo, Yuhua Wang, Helena Korpelainen, Chunyang Li. (2005). Allozyme variation in natural populations of Picea asperata. Silva Fennica vol. 39 no. 2 article id 381. https://doi.org/10.14214/sf.381
Keywords: allozymes; genetic variability; Picea asperata
Abstract | View details | Full text in PDF | Author Info
A survey of allozymic alleles and genetic diversity was conducted for ten natural populations of Picea asperata Mast. originating from the mountains of Southwest China. A total of twenty-seven alleles at seventeen loci were observed. Ten of the loci were found monomorphic. Our results showed that the populations sampled were characterized by low genetic diversity (mean He = 0.096) and a low level of inbreeding (mean Fis = 0.005). The UPGMA tree of genetic relationships indicated that there was significant differentiation among populations. The coefficient of genetic differentiation among populations, based on Fst, equaled 0.311. Such extensive inter-populational differentiation detected in P. asperata could have resulted from allele frequency divergence among populations, particularly, in one population. Introgression from another species, variation in environmental conditions, and differing selection pressures could be some of the factors attributing to significant differences among populations. In addition, our results showed that the geographic and genetic distances were not correlated in the populations of P. asperata. Based on the genetic information obtained, we concluded that monitoring appropriate genetic markers may be an effective means of identifying potential genetic changes occurring during forest tree evolution.
  • Luo, Sichuan Academy of Forestry, Chengdu 610081, P. R. China E-mail: jl@nn.cn
  • Wang, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, P. R. China E-mail: yw@nn.cn
  • Korpelainen, Department of Applied Biology, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: hk@nn.fi
  • Li, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China E-mail: licy@cib.ac.cn (email)
article id 397, category Research article
Nuutti Kiljunen. (2005). Pricing the risk of the quality-guarantee in a stand establishment service. Silva Fennica vol. 39 no. 1 article id 397. https://doi.org/10.14214/sf.397
Keywords: quality; forest regeneration; risk; guarantee
Abstract | View details | Full text in PDF | Author Info
A stand-establishment service concept with quality guarantee was analysed. Here, the quality of stand establishment was assessed as the density of good quality seedlings evenly distributed on the plantation three years after planting. The amount of adequate premiums for the guarantee service and the risks accumulating to the service provider were studied. Monte Carlo simulation was used as a tool for analyzing the risks accumulating to the service provider of the stand-establishment in operational environments of different sizes. The premiums calculated to cover the expected amount of claims caused by the plantations not meeting the pre-set criteria were about 4–8% in addition to the approximated costs of stand establishment. The criteria used for determining the success or failure in a stand have a marked effect on the amount of premiums with a reasonable risk of ruin.
  • Kiljunen, Finnish Forest Research Institute, Suonenjoki Research Station, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: nuutti.kiljunen@metla.fi (email)
article id 396, category Research article
Timo Pukkala, Mikko Kurttila. (2005). Examining the performance of six heuristic optimisation techniques in different forest planning problems. Silva Fennica vol. 39 no. 1 article id 396. https://doi.org/10.14214/sf.396
Keywords: genetic algorithms; simulated annealing; ecological planning; habitat suitability index (HSI); Hero; random search; tabu search
Abstract | View details | Full text in PDF | Author Info
The existence of multiple decision-makers and goals, spatial and non-linear forest management objectives and the combinatorial nature of forest planning problems are reasons that support the use of heuristic optimisation algorithms in forest planning instead of the more traditional LP methods. A heuristic is a search algorithm that does not necessarily find the global optimum but it can produce relatively good solutions within reasonable time. The performance of different heuristics may vary depending on the complexity of the planning problem. This study tested six heuristic optimisation techniques in five different, increasingly difficult planning problems. The heuristics were evaluated with respect to the objective function value that the techniques were able to find, and the time they consumed in the optimisation process. The tested optimisation techniques were 1) random ascent (RA), 2) Hero sequential ascent technique (Hero), 3) simulated annealing (SA), 4) a hybrid of SA and Hero (SA+Hero), 5) tabu search (TS) and 6) genetic algorithm (GA). The results, calculated as averages of 100 repeated optimisations, were very similar for all heuristics with respect to the objective function value but the time consumption of the heuristics varied considerably. During the time the slowest techniques (SA or GA) required for convergence, the optimisation could have been repeated about 200 times with the fastest technique (Hero). The SA+Hero and SA techniques found the best solutions for non-spatial planning problems, while GA was the best in the most difficult problems. The results suggest that, especially in spatial planning problems, it is a benefit if the method performs more complicated moves than selecting one of the neighbouring solutions. It may also be beneficial to combine two or more heuristic techniques.
  • Pukkala, University of Joensuu, Faculty of Forestry, P.O. BOX 111, FI-80101 Joensuu, Finland E-mail: timo.pukkala@forest.joensuu.fi (email)
  • Kurttila, Finnish Forest Research Institute, Joensuu Research Centre, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: mk@nn.fi
article id 405, category Research article
Timo Saksa. (2004). Regeneration process from seed crop to saplings – a case study in uneven-aged Norway spruce-dominated stands in southern Finland. Silva Fennica vol. 38 no. 4 article id 405. https://doi.org/10.14214/sf.405
Keywords: boreal forest; Picea abies; regeneration; uneven-aged
Abstract | View details | Full text in PDF | Author Info
The dynamics of spruce regeneration, from seed crop to saplings, was studied based on five permanent plots in uneven-aged, spruce-dominated, boreal forest stands, cut with single-tree selection in the beginning of the 1990’s. The annual fluctuation of the spruce seed crop was very similar in uneven-aged and even-aged stands. The correlation between seed crop and number of germinants was significant; but stem number, basal area or volume of the stand did not influence on seedling emergence. The effects of good seed crops were seen as peaks or an increase in the number of germinants and smallest seedlings. The mean number of ‘stabilised’ spruce seedlings (height 11 cm to 130 cm) varied from 6000 ha–1 to over 25 000 spruce seedlings ha–1 from one monitoring plot to another. On a monitoring plot the number of ‘stabilised’ spruce seedlings was stable over time. Neither stand basal area nor stand volume influenced the number of ‘stabilised’ spruce seedlings, but the height of these seedlings was higher on subplots with lower stand volume and smaller basal area. In this study the monitoring period, 5–10 years, was too short to obtain reliable figures for ingrowth, i.e. the transition of seedlings to the sapling stage (h > 130 cm). The adjusted mean ingrowth was 26 stems ha–1 year–1.
  • Saksa, Finnish Forest Research Institute, Suonenjoki Research Station, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@metla.fi (email)
article id 422, category Research article
Mika Nieminen. (2004). Export of dissolved organic carbon, nitrogen and phosphorus following clear-cutting of three Norway spruce forests growing on drained peatlands in southern Finland. Silva Fennica vol. 38 no. 2 article id 422. https://doi.org/10.14214/sf.422
Keywords: hydrochemistry; forest regeneration; peatland forestry; leaching; nutrient losses
Abstract | View details | Full text in PDF | Author Info
The effect of clear-cutting on the concentrations of dissolved organic carbon (DOC), organic nitrogen (DON), NH4+, NO3–, and P in outflow water from three productive, Norway spruce dominated drained peatlands (RCC, VCC-1, VCC-2) were studied. Changes in runoff and transport loads (concentration x runoff) at two of the catchments during the frost-free period are also presented. Approximately 40% of the area was cut at RCC and VCC-2, and 72% at VCC-1. The volume removed was 250 m3 ha–1 at RCC, 259 m3 ha–1 at VCC-1, and for VCC-2, 317 m3 ha–1. The mean annual increase in outflow concentrations of DOC during the first four years after clear-cutting was 9.0 mg l–1 at RCC, 22.8 mg l–1 at VCC-1 and 8.4 mg l–1 at VCC-2. Corresponding increases in the forms of nitrogen were: 0.23, 0.51 and 0.16 mg DON l–1; 0.06, 0.31 and 0.04 mg NH4+-N l–1; and 0.05, 0.12 and 0.22 mg NO3–-N l–1. Clear-cutting did not significantly (p > 0.05) increase P concentrations. The increase in non-frost season runoff over the first three years after clear-cutting was 107 mm at RCC and 207 mm at VCC-1. The export loads of DOC during the non-frost season increased by 80 kg ha–1 at RCC and by 184 kg ha–1 at VCC-1 over the first three years. Corresponding increases for the other studied solutes were: 1.78 and 3.98 kg DON ha–1; 0.39 and 1.49 kg NH4+-N ha–1; 0.45 and 0.48 kg NO3–-N ha–1, and 0.09 and 0.06 kg P ha–1. The study demonstrated that clear-cutting may significantly increase the export of DOC and different forms of nitrogen from drained productive peatlands while only small increases in phosphorus export may occur.
  • Nieminen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: mika.nieminen@metla.fi (email)
article id 491, category Research article
Lars Rytter, Lars-Göran Stener. (2003). Clonal variation in nutrient content in woody biomass of hybrid aspen (Populus tremula L. x P. tremuloides Michx.). Silva Fennica vol. 37 no. 3 article id 491. https://doi.org/10.14214/sf.491
Keywords: growth; branches; genetic correlations; heritability; nutrient concentration; nutrient removal; stems
Abstract | View details | Full text in PDF | Author Info
Differences in the nutrient concentrations and nutrient amounts of stems and branches amongst clones of hybrid aspen (Populus tremula L. x P. tremuloides Michx.) were investigated. Seven clones with superior and seven with medium growth rates were selected from a test of 119 clones in southern Sweden. Four trees per clone were randomly identified and harvested in dormant conditions. Sample discs from the stems and branches were collected and analysed for N, K, P, Ca, Mg, and S concentrations, as well as wood density. The analyses revealed significant genetic differences in wood density, K, P, and Mg concentrations in the stems. There were weak (non-significant) and negative genetic correlations between stem volume and concentrations of all the nutrients, except potassium, suggesting that nutrient-efficient clones could be selected without significantly sacrificing genetic gain for growth. In the branches K, Ca, and Mg concentrations differed significantly among clones. After selecting more nutrient efficient clones, the potential savings of nutrients compared with current hybrid aspen material was estimated to be around 5%, which seems fairly low, at least in a short-term perspective. However, the use of clones with different nutrient storage strategies may be regarded as a possible way in the long run to save nutrients in hybrid aspen ecosystems, or of removing them when sludge is applied.
  • Rytter, Forestry Research Institute of Sweden, Skogforsk, Ekebo 2250, SE-26890, Svalöv, Sweden E-mail: lars.rytter@skogforsk.se (email)
  • Stener, Forestry Research Institute of Sweden, Skogforsk, Ekebo 2250, SE-26890, Svalöv, Sweden E-mail: lgs@nn.se
article id 504, category Research article
Sylvain Jutras, Hannu Hökkä, Virpi Alenius, Hannu Salminen. (2003). Modeling mortality of individual trees in drained peatland sites in Finland. Silva Fennica vol. 37 no. 2 article id 504. https://doi.org/10.14214/sf.504
Keywords: Pinus sylvestris; Betula pubescens; simulation; peatlands; mortality; generalized linear mixed models; multilevel models
Abstract | View details | Full text in PDF | Author Info
Multilevel logistic regression models were constructed to predict the 5-year mortality of Scots pine (Pinus sylvestris L.) and pubescent birch (Betula pubescens Ehrh.) growing in drained peatland stands in northern and central Finland. Data concerning tree mortality were obtained from two successive measurements of the National Forest Inventory-based permanent sample plot data base covering pure and mixed stands of Scots pine and pubescent birch. In the modeling data, Scots pine showed an average observed mortality of 2.73% compared to 2.98% for pubescent birch. In the model construction, stepwise logistic regression and multilevel models methods were applied, the latter making it possible to address the hierarchical data, thus obtaining unbiased estimates for model parameters. For both species, mortality was explained by tree size, competitive position, stand density, species admixture, and site quality. The expected need for ditch network maintenance or re-paludification did not influence mortality. The multilevel models showed the lowest bias in the modeling data. The models were further validated against independent test data and by embedding them in a stand simulator. In 100-year simulations with different initial stand conditions, the models resulted in a 72% and 66% higher total mortality rate for the stem numbers of pine and birch, respectively, compared to previously used mortality models. The developed models are expected to improve the accuracy of stand forecasts in drained peatland sites.
  • Jutras, Département des sciences du bois et de la forêt, Université Laval, Ste-Foy, Québec, G1K 7P4, Canada E-mail: sj@nn.ca
  • Hökkä, Finnish Forest Research Institute, Rovaniemi Research Station, P.O. Box 16, FIN 96301 Rovaniemi, Finland E-mail: hannu.hokka@metla.fi (email)
  • Alenius, Finnish Forest Research Institute, Rovaniemi Research Station, P.O. Box 16, FIN 96301 Rovaniemi, Finland E-mail: va@nn.fi
  • Salminen, Finnish Forest Research Institute, Rovaniemi Research Station, P.O. Box 16, FIN 96301 Rovaniemi, Finland E-mail: hs@nn.fi
article id 508, category Research article
Kai Vellak, Jaanus Paal, Jaan Liira. (2003). Diversity and distribution pattern of bryophytes and vascular plants in a boreal spruce forest. Silva Fennica vol. 37 no. 1 article id 508. https://doi.org/10.14214/sf.508
Keywords: boreal forests; correlation; general linear models; Estonia; field layer; ground layer; spatial patterns
Abstract | View details | Full text in PDF | Author Info
Small scale pattern of bryophyte communities is one of the remarkable sources of diversity in species-poor boreal forests. By means of correlation and general linear model approaches, the relationships between bryophyte vegetation and upper layers, as well as the response of ground and field layer species to several environmental factors, was analyzed in a boreal spruce forest in South-East Estonia. Of the studied factors, the strongest influence on the diversity and spatial distribution of ground and field layer species was found for ‘distance from nearest tree’. Species from different layers react differently to the proximity of trees. Species richness of bryophytes is higher further from trees, whereas more vascular plant species prefer to grow in the vicinity of tree trunks. For bryophyte species richness, the pH of the decay horizon is also important; fewer bryophyte species occur in more acid conditions.
  • Vellak, Institute of Zoology and Botany, Estonian Agricultural University, 181 Riia str., 51014 Tartu, Estonia; Institute of Botany and Ecology, University of Tartu, 40 Lai Str., 51005 Tartu, Estonia E-mail: kvellak@zbi.ee (email)
  • Paal, Institute of Botany and Ecology, University of Tartu, 40 Lai Str., 51005 Tartu, Estonia E-mail: jp@nn.ee
  • Liira, Institute of Botany and Ecology, University of Tartu, 40 Lai Str., 51005 Tartu, Estonia E-mail: jl@nn.ee
article id 518, category Research article
Mats Hannerz, Curt Almqvist, Roland Hörnfeldt. (2002). Timing of seed dispersal in Pinus sylvestris stands in central Sweden. Silva Fennica vol. 36 no. 4 article id 518. https://doi.org/10.14214/sf.518
Keywords: natural regeneration; Scots pine; seed fall
Abstract | View details | Full text in PDF | Author Info
The objective of the study presented here was to describe the variation in timing of seed dispersal from Scots pine (Pinus sylvestris L.) seed trees in central Sweden. Seeds were collected in traps at two sites, for three years at one, and four years at the other . The traps were emptied from March to August each year at 1–2 week intervals during the main period of seed dispersal. The annual seed fall varied between 200 000 and 1.6 million seeds per hectare. The seed fall started in mid to late April, shortly after the heat sum had started to accumulate. The most intensive seed fall took place in early to mid May. The peak period, when 50% of the total seed dispersal occurred, lasted for 18–28 days at the different sites and years. The variation in timing among years seemed to be mainly due to climatic factors – high temperatures promoted seed dispersal, for instance. The results may be useful for planning the time of scarification to optimise the natural regeneration of Scots pine. The data suggest that scarification in the spring, no later than mid-May, would generally create a good seed-bed for most of the current year’s seeds, whereas scarification in late May or June would bury a large proportion of this cohort.
  • Hannerz, The Forestry Research Institute of Sweden (SkogForsk) Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: mats.hannerz@skogforsk.se (email)
  • Almqvist, The Forestry Research Institute of Sweden (SkogForsk) Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: ca@nn.se
  • Hörnfeldt, Swedish University of Agricultural Sciences, Dept. of Forest Products and Markets, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: rh@nn.se
article id 564, category Research article
Brett G. Purdy, S. Ellen Macdonald, Mark R. T. Dale. (2002). The regeneration niche of white spruce following fire in the mixedwood boreal forest. Silva Fennica vol. 36 no. 1 article id 564. https://doi.org/10.14214/sf.564
Keywords: boreal forest; regeneration; natural disturbance; white spruce; mycorrhizae
Abstract | View details | Full text in PDF | Author Info
Early establishment of white spruce (Picea glauca) in mixedwood boreal forest stands following fire was examined at several times-since-fire (1-, 2-, 4-, 6-, 14-years). Abiotic and biotic conditions in the stands were assessed at two scales, tree plot (5 m x 5 m) and microsite (1 m x 1 m), along with presence, density and height of white spruce seedlings. Germination and survival of seed sown 1- and 4-years post fire were quantified. Survival and growth of nursery-grown seedlings, and mycorrhizal colonization, survival and growth of sterile seedlings, planted 1-year post-fire were assessed. At the tree plot scale, presence of white spruce seedlings 1-year post-fire could be reliably predicted by organic layer depth and distance to and strength of seed source. In contrast, none of the biotic or abiotic factors measured was strongly correlated with occurrence or density of white spruce seedlings 6- and 14- years post-fire. At the microsite scale, seedling recruitment immediately post-fire was limited to a distinct subset of available microsites (greater % cover of downed wood and moss, lower % cover of litter and herbaceous vegetation). Likewise, seedling occurrence in older burns was associated with distinct microsite conditions; although this was more likely an effect of white spruce presence, rather than the cause. Less than 3% of seed sown 1 yr post-fire survived to become 1yr old germinants, survival was 41% over the next three years. Availability of suitable regeneration microsites declines rapidly with time-since-fire; less than 0.3% of seed sown 4 yrs post-fire survived one year. High rates of mycorrhizal colonization were found on white spruce seedlings planted 1-year post-fire, including early and late stage fungal species. Microsite characteristics were only weakly correlated with mycorrhizal fungal communities. We propose that immediate post-fire recruitment of white spruce is a key process in mixedwood boreal succession.
  • Purdy, Dept. of Renewable Resources, University of Alberta, Edmonton, AB, Canada T6G 2E3 E-mail: bgp@nn.ca
  • Macdonald, Dept. of Renewable Resources, University of Alberta, Edmonton, AB, Canada T6G 2E3 E-mail: ellen.macdonald@ualberta.ca (email)
  • Dale, Dale, Dept. of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9 E-mail: mrtd@nn.ca
article id 556, category Research article
Timo Kuuluvainen, Juha Mäki, Leena Karjalainen, Hannu Lehtonen. (2002). Tree age distributions in old-growth forest sites in Vienansalo wilderness, eastern Fennoscandia. Silva Fennica vol. 36 no. 1 article id 556. https://doi.org/10.14214/sf.556
Keywords: forest dynamics; boreal forest; regeneration; age structure; fire disturbance
Abstract | View details | Full text in PDF | Author Info
The age and size of trees was sampled and measured on eight sample plots (0.2 ha each) within a Pinus sylvestris -dominated boreal forest landscape in Vienansalo wilderness, Russian Karelia. The fire history of these plots was obtained from a previous dendrochronological study. All the studied sample plots showed a wide and uneven distribution of tree ages, but the shape of the age distributions of trees as well as tree species composition varied substantially. Trees over 250 years of age occurred in every studied plot, despite its small size. This suggests that old Pinus were common and rather evenly distributed in the landscape matrix. The oldest Pinus tree was 525 years of age. The correlations between tree age and size were often weak or even nil. In Pinus the correlation between age and diameter was stronger than that between age and height. In the dominant tree species Pinus and Picea, the largest trees were not the oldest trees. The tree age distributions together with the fire history data indicated that the past fires have not been stand replacing, as many of the older Pinus had survived even several fires. Tree age classes that had regenerated after the last fire were most abundant and dominated by Picea and/or deciduous trees, while the trees established before the last fire were almost exclusively Pinus. The results suggest that periodic occurrence of fire is important for the maintenance of the Pinus-dominated landscape. This is because fire kills most Picea and deciduous trees and at the same time enhances conditions for Pinus regeneration, facilitated by available seed from the continuous presence of old fire-tolerant Pinus trees.
  • Kuuluvainen, Department of Forest Ecology, University of Helsinki, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: timo.kuuluvainen@helsinki.fi (email)
  • Mäki, Department of Forest Ecology, University of Helsinki, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: jm@nn.fi
  • Karjalainen, Department of Forest Ecology, University of Helsinki, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: lk@nn.fi
  • Lehtonen, Faculty of Forestry, University of Joensuu, P.O. Box 24, FIN-80101 Joensuu, Finland E-mail: hl@nn.fi
article id 601, category Research article
Ricardo Alía, Javier Moro-Serrano, Eduardo Notivol. (2001). Genetic variability of Scots pine (Pinus sylvestris) provenances in Spain: growth traits and survival. Silva Fennica vol. 35 no. 1 article id 601. https://doi.org/10.14214/sf.601
Keywords: Spain; Scots pine; genetic variation; provenances; GE interaction
Abstract | View details | Full text in PDF | Author Info
Plants obtained from seed of 16 Spanish and 6 German provenances of Scots pine (Pinus sylvestris L.) were installed at five trial sites distributed throughout the natural range of the species in Spain. Five years after planting (7 years of age) the experimental material was measured for total height, diameter, number of twigs at the fourth year whorl and survival. The analysis confirmed that the rate of height growth of the Spanish is lower than that of the German provenances, whereas for the other traits the best Spanish compare favourably with the Germans. Provenance by site interaction was very significant (P < 0.01) for most traits. Attempts to model the interaction of Spanish provenances on height by simultaneous introduction of some climatic and geographic covariates on both factors were not successful but a multiplicative model with one bilinear term was enough to provide a sensible explanation of this interaction. Usually, provenances closest to each trial site were found better adapted than more distant ones but some provenances of close origin presented a different behaviour. Processes of adaptation and selection of these ancient populations could be considered as the main factors to cause this interaction.
  • Alía, CIFOR-INIA, Unidad de Mejora Forestal, 28080 Madrid, Spain E-mail: ra@nn.es
  • Moro-Serrano, CIFOR-INIA, Unidad de Mejora Forestal, 28080 Madrid, Spain E-mail: jmoro@inia.es (email)
  • Notivol, Unidad de Recursos Forestales, SIA-DGA, Ca de Montañana 179, 50080 Zaragoza, Spain E-mail: en@nn.es
article id 689, category Research article
Erik W. Andersson, Kostas A. Spanos, Timothy J. Mullin, Dag Lindgren. (1998). Phenotypic selection compared to restricted combined index selection for many generations. Silva Fennica vol. 32 no. 2 article id 689. https://doi.org/10.14214/sf.689
Keywords: genetic diversity; heritability; status number; phenotypic selection; index selection
Abstract | View details | Full text in PDF | Author Info
A breeding population has been subjected to repeated selection and crossing by simulation. Unrestricted phenotypic selection and restricted combined index selection were compared at the same effective number for five generations. Results show that phenotypic selection often achieves the gain and diversity possible to achieve by combined index selection but the relative efficiency is different for different family sizes and heritabilities. When phenotypic selection was compared with restricted combined index method at low heritabilities, both methods performed almost equally in terms of gain at the same effective number in small family sizes, although in large families, phenotypic selection was less efficient. At high heritabilities phenotypic selection was as efficient as combined index selection. Phenotypic selection was more efficient in conserving additive variance than combined index selection over five generations compared at the same gain and effective number. The introduction of a dominance component to the total variance had little effect. An increased breeding population size by a factor of ten resulted in an increased additive gain by app. 15%. The conclusion is that even though combined index selection is superior in identifying and extracting the potential for breeding achievements, it is generally not performing better than mass selection when compared at the same effective population size in small families.
  • Andersson, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden E-mail: erik.andersson@genfys.slu.se (email)
  • Spanos, N.AG.RE.F.-Forest Research Institute, 57006 Vassilika, Thessaloniki, Greece E-mail: kas@nn.gr
  • Mullin, Genesis Forest Science Canada Inc., C.P. 64 Succursale Haute-Ville, Québec, QC G1R 4M8 Canada E-mail: tjm@nn.ca
  • Lindgren, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden E-mail: dl@nn.se

Category : Review article

article id 10516, category Review article
Faujiah N. Ritonga, Jacob N. Ngatia, Run X. Song, Umar Farooq, Sonia Somadona, Andi T. Lestari, Su Chen. (2021). Abiotic stresses induced physiological, biochemical, and molecular changes in Betula platyphylla: a review. Silva Fennica vol. 55 no. 3 article id 10516. https://doi.org/10.14214/sf.10516
Keywords: antioxidant; cis-acting elements; gene; ROS production; transcription factor
Highlights: Abiotic stress influence Betula platyphylla growth, development, and yield production by impairing physiological, biochemical, and molecular functions; Overexpression or RNAi line of transcription factors enhance the abiotic stress tolerance of B. platyphylla; MYB and AP2/ERF are the most frequently transcription factor family that has been explored over the last two decades in B. platyphylla under abiotic stress.
Abstract | Full text in HTML | Full text in PDF | Author Info

Abiotic stress is one of the major factors in reducing plant growth, development, and yield production by interfering with various physiological, biochemical, and molecular functions. In particular, abiotic stress such as salt, low temperature, heat, drought, UV-radiation, elevated CO2, ozone, and heavy metals stress is the most frequent study in Betula platyphylla Sukaczev. Betula platyphylla is one of the most valuable tree species in East Asia facing abiotic stress during its life cycle. Using transgenic plants is a powerful tool to increase the B. platyphylla abiotic stress tolerance. Generally, abiotic stress reduces leaves water content, plant height, fresh and dry weight, and enhances shed leaves as well. In the physiological aspect, salt, heavy metal, and osmotic stress disturbs seed germination, stomatal conductance, chlorophyll content, and photosynthesis. In the biochemical aspect, salt, drought, cold, heat, osmotic, UV-B radiation, and heavy metal stress increases the ROS production of B. platyphylla cells, resulting in the enhancement of enzymatic antioxidant (SOD and POD) and non-enzymatic antioxidant (proline and AsA) to reduce the ROS accumulation. Meanwhile, B. platyphylla upregulates various genes, as well as proteins to participate in abiotic stress tolerance. Based on recent studies, several transcription factors contribute to increasing abiotic stress tolerance in B. platyphylla, including BplMYB46, BpMYB102, BpERF13, BpERF2, BpHOX2, BpHMG6, BpHSP9, BpUVR8, BpBZR1, BplERD15, and BpNACs. These transcription factors bind to different cis-acting elements to upregulate abiotic stress-related genes, resulting in the enhancement of salt, drought, cold, heat, osmotic, UV-B radiation, and heavy metal tolerance. These genes along with phytohormones mitigate the abiotic stress. This review also highlights the candidate genes from another Betulacea family member that might be contributing to increasing B. platyphylla abiotic stress tolerance.

  • Ritonga, State Key Laboratory of Tree Genetics and Breeding, Forestry College, Northeast Forestry University, Harbin 150040, China E-mail: ritongafaujiah@ymail.com
  • Ngatia, College of Wildlife and Protected Areas, Northeast Forestry University, Harbin 150040, China E-mail: jacob.ngatia3@gmail.com
  • Song, State Key Laboratory of Tree Genetics and Breeding, Forestry College, Northeast Forestry University, Harbin 150040, China E-mail: 13359850710@163.com
  • Farooq, College of Life Science, Northeast Forestry University, Harbin 150040, China E-mail: uf@nn.ch
  • Somadona, College of Agriculture, Riau University, Pekanbaru 28293, Indonesia E-mail: sonia_hut@yahoo.co.id
  • Lestari, Forestry Major, College of Agriculture, Mataram University, Mataram 83125, Indonesia E-mail: atlestari@unram.ac.id
  • Chen, State Key Laboratory of Tree Genetics and Breeding, Forestry College, Northeast Forestry University, Harbin 150040, China E-mail: chensu@nefu.edu.cn (email)
article id 10172, category Review article
Ulf Sikström, Karin Hjelm, Kjersti Holt Hanssen, Timo Saksa, Kristina Wallertz. (2020). Influence of mechanical site preparation on regeneration success of planted conifers in clearcuts in Fennoscandia – a review. Silva Fennica vol. 54 no. 2 article id 10172. https://doi.org/10.14214/sf.10172
Keywords: natural regeneration; regeneration chain; seedling growth; coniferous seedlings; disturbed soil surface; seedling survival
Highlights: Mechanical site preparation (MSP) increases seedling survival rates by 15–20%; Survival rates of 80–90% ca. 10 years after MSP and planting conifers are possible; MSP can increase tree height 10–15 years after planting by 10–25%; The increase in growth rate associated with MSP may be temporary, but the height enhancement probably persists.
Abstract | Full text in HTML | Full text in PDF | Author Info

In the Nordic countries Finland, Norway and Sweden, the most common regeneration method is planting after clearcutting and, often, mechanical site preparation (MSP). The main focus of this study is to review quantitative effects that have been reported for the five main MSP methods in terms of survival and growth of manually planted coniferous seedlings of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) in clearcuts in these three countries. Meta analyses are used to compare the effects of MSP methods to control areas where there was no MSP and identify any relationships with temperature sum and number of years after planting. In addition, the area of disturbed soil surface and the emergence of naturally regenerated seedlings are evaluated. The MSP methods considered are patch scarification, disc trenching, mounding, soil inversion and ploughing. Studies performed at sites with predominately mineral soils (with an organic topsoil no thicker than 0.30 m), in boreal, nemo-boreal and nemoral vegetation zones in the three Fenno-Scandinavian countries are included in the review. Data from 26 experimental and five survey studies in total were compiled and evaluated. The results show that survival rates of planted conifers at sites where seedlings are not strongly affected by pine weevil (Hylobius abietis L.) are generally 80–90% after MSP, and 15–20 percent units higher than after planting in non-prepared sites. The experimental data indicated that soil inversion and potentially ploughing (few studies) give marginally greater rates than the other methods in this respect. The effects of MSP on survival seem to be independent of the temperature sum. Below 800 degree days, however, the reported survival rates are more variable. MSP generally results in trees 10–25% taller 10–15 years after planting compared to no MSP. The strength of the growth effect appears to be inversely related to the temperature sum. The compiled data may assist in the design, evaluation and comparison of possible regeneration chains, i.e. analyses of the efficiency and cost-effectiveness of multiple combinations of reforestation measures.

  • Sikström, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: ulf.sikstrom@skogforsk.se
  • Hjelm, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden E-mail: karin.hjelm@skogforsk.se (email)
  • Holt Hanssen, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, Norway E-mail: kjersti.hanssen@nibio.no
  • Saksa, Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@luke.fi
  • Wallertz, Swedish University of Agricultural Sciences (SLU), Asa Forest Research Station, SE-360 30 Lammhult, Sweden E-mail: kristina.wallertz@slu.se
article id 552, category Review article
Timo Kuuluvainen. (2002). Natural variability of forests as a reference for restoring and managing biological diversity in boreal Fennoscandia. Silva Fennica vol. 36 no. 1 article id 552. https://doi.org/10.14214/sf.552
Keywords: biodiversity; ecosystem management; disturbance dynamics; succession; sustainable forestry; heterogeneity; hierarchy; scaling; spatiotemporal dynamics
Abstract | View details | Full text in PDF | Author Info
In Fennoscandia, use of the natural forest as a reference for restoration and management of forest biodiversity has been widely accepted. However, limited understanding of the structure and dynamics of the natural forest has hampered the applications of the natural variability approach. This is especially the case in areas, where the natural forests have almost totally vanished. This review was motivated by the idea that despite these difficulties the essential features of the natural forest can be reconstructed based on biological archives, historical documents, research done in adjacent natural areas, and modeling. First, a conceptual framework for analyzing the relationship between forest structure, dynamics and biodiversity is presented. Second, the current understanding of the structure and dynamics of natural forests at different spatiotemporal scales in boreal Fennoscandia is reviewed. Third, the implications of this knowledge, and gaps in knowledge, on research and on practical restoration and management methods aimed at forest biodiversity conservation are discussed. In conclusion, naturally dynamic forest landscapes are complex, multiscaled hierarchical systems. Current forest management methods create disturbance and successional dynamics that are strongly scale-limited when compared with the natural forest. To restore some of the essential characteristics of the natural forest’s multiscale heterogeneity, diversification of silvicultural and harvesting treatments, as guided by natural disturbance dynamics, is needed to produce more variation in disturbance severity, quality, extent, and repeatability.
  • Kuuluvainen, Department of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: timo.kuuluvainen@helsinki.fi (email)

Category : Research note

article id 10524, category Research note
Arnis Gailis, Pauls Zeltiņš, Roberts Matisons, Andis Purviņš, Juris Augustovs, Valts Vīndedzis, Āris Jansons. (2021). Local adaptation of phenotypic stem traits distinguishes two provenance regions of silver birch in Latvia. Silva Fennica vol. 55 no. 2 article id 10524. https://doi.org/10.14214/sf.10524
Keywords: Betula pendula; population genetics; genetic parameters; climate-smart forestry; phenotypic traits
Highlights: Two provenance subregions in Latvia – coastal and inland – were distinguished; Silver birch populations in inland region possessed better growth, higher heritability, and phenotypic plasticity; Moderate to high heritability for stem quality was estimated in both regions; Silver birch from inland region possesses higher potential for improvement of adaptability.
Abstract | Full text in HTML | Full text in PDF | Author Info

Populations of tree species with a wide geographic range, such as silver birch (Betula pendula Roth), show genetic specialization to native environments, while maintaining high phenotypical plasticity. Accordingly, assessment of local specialization is essential for adaptive management. The aim of the study was to detect geographic patterns of local adaptation of growth and stem quality based on two open-pollinated progeny trials in Latvia testing local material. Two provenance regions differing by continentality were distinguished, which also differed in genetic control of growth traits, likely originating from the post-glacial recolonization of vegetation and subsequent natural adaptation. Heritability of the traits was estimated for each of the distinguished regions, indicating differing patterns of genetic adaptation and potential for future selection. Trees from the more continental inland showed superior growth and possessed higher heritability. The coastal provenance region showed slower growth and intermediate heritability of the respective traits. Moderate to high heritability for stem quality traits was estimated irrespectively of region. Overall, better growth and higher heritability suggests that anthropogenic selection within the best inland provenances may constitute better performing and adaptable breeding population compared to the coastal one. Still, overlapping phenotypical variation and heritability of quality traits implies improved stemwood quality for plywood regardless of the provenance region. High adaptive capacity of silver birch genotypes suggests ability to cope with climatic changes, highlighting its potential for climate-smart forestry.

  • Gailis, Latvian State Forest Research Institute Silava, 111 Rigas street, LV-2169, Salaspils, Latvia E-mail: arnis.gailis@silava.lv
  • Zeltiņš, Latvian State Forest Research Institute Silava, 111 Rigas street, LV-2169, Salaspils, Latvia E-mail: pauls.zeltins@silava.lv (email)
  • Matisons, Latvian State Forest Research Institute Silava, 111 Rigas street, LV-2169, Salaspils, Latvia ORCID https://orcid.org/0000-0002-4042-0689 E-mail: roberts.matisons@silava.lv
  • Purviņš, Latvian State Forest Research Institute Silava, 111 Rigas street, LV-2169, Salaspils, Latvia E-mail: andis.purvins@silava.lv
  • Augustovs, Latvian State Forest Research Institute Silava, 111 Rigas street, LV-2169, Salaspils, Latvia E-mail: juris.augustovs@silava.lv
  • Vīndedzis, Latvian State Forest Research Institute Silava, 111 Rigas street, LV-2169, Salaspils, Latvia E-mail: valts.vindedzis@silava.lv
  • Jansons, Latvian State Forest Research Institute Silava, 111 Rigas street, LV-2169, Salaspils, Latvia ORCID https://orcid.org/0000-0001-7981-4346 E-mail: aris.jansons@silava.lv
article id 7818, category Research note
Roberts Matisons, Guntars Šņepsts, Līga Puriņa, Jānis Donis, Āris Jansons. (2018). Dominant height growth of European beech at the northeasternmost stands in Europe. Silva Fennica vol. 52 no. 1 article id 7818. https://doi.org/10.14214/sf.7818
Keywords: site index; Fagus sylvatica; generalized algebraic difference approach; height models
Highlights: The dominant height growth of the introduced European beech was modelled using the generalised algebraic difference approach; The Chapman-Richards and Sloboda models showed the best fit to the data; Height growth of the second generation trees exceeded the first generation trees; In the western part of Latvia, height growth of beech exceeded that in southern Sweden.
Abstract | Full text in HTML | Full text in PDF | Author Info

The height growth of trees influences the productivity of stands and the competitiveness of species, shaping the range of their distribution. Dominant height growth was assessed for European beech (Fagus sylvatica L.), growing outside of its natural distribution range in the western part of Latvia. In 10 neighbouring experimental stands, 20 dominant trees were felled for stem analysis. Height growth was modelled using the generalised algebraic difference approach, applying several non-linear equations and mixed procedures. The Chapman-Richards and Sloboda models showed the best fit to the data. Height growth of the second generation (younger) trees exceeded that of the first generation, and followed curve for a higher site index, suggesting sufficient adaptation and improving conditions. Height growth of the studied beech exceeded predictions for beech in southern Sweden, which is considered to be the northern limit of the species range, yet the growth pattern differed. In Latvia, slower height growth was estimated for site indices < 32 m (in 100 years) during the first 60 years, yet larger maximal height was predicted, suggesting a longer establishment period. Nevertheless, the improving height growth indicated increasing potential for the application of the species in commercial forestry, and an expansion of the species within the region even during the 21th century.

  • Matisons, Latvian State Forest Research Institute “Silava”, Rīgas str. 111, Salaspils, Latvia, LV2169 E-mail: robism@inbox.lv (email)
  • Šņepsts, Latvian State Forest Research Institute “Silava”, Rīgas str. 111, Salaspils, Latvia, LV2169 E-mail: guntars.snepsts@silava.lv
  • Puriņa, Latvian State Forest Research Institute “Silava”, Rīgas str. 111, Salaspils, Latvia, LV2169 E-mail: liga.purina@silava.lv
  • Donis, Latvian State Forest Research Institute “Silava”, Rīgas str. 111, Salaspils, Latvia, LV2169 E-mail: janis.donis@silava.lv
  • Jansons, Latvian State Forest Research Institute “Silava”, Rīgas str. 111, Salaspils, Latvia, LV2169 E-mail: aris.jansons@silava.lv
article id 5644, category Research note
Jiří Korecký, Jan Bílý, Petr Sedlák, Milan Lstibůrek. (2017). Innovative multiplex and its evaluation for effective genotyping of wild cherry. Silva Fennica vol. 51 no. 3 article id 5644. https://doi.org/10.14214/sf.5644
Keywords: genetic structure; microsatellites; Prunus avium; SSRs; pseudo 15-plex; one-run genotyping
Highlights: We present simple and cost-efficient method of SSR genotyping in cherry species; Seven of fifteen previously published primer sequences have been altered in order to produce complementary amplicons in pseudo 15-plex; The effectiveness and discriminatory power of established multiplex were verified by SSRs analysis of 48 wild cherry trees.
Abstract | Full text in HTML | Full text in PDF | Author Info

Trees from the family Rosaceae play an important role in forest and agricultural ecosystems. Therefore, they are often an object of interest for both forest and horticultural tree breeders. Here, we present the utilization of an effective microsatellite (SSRs) genotyping method for wild cherry (Prunus avium L.) and verified the discriminatory power of the presented multiplex by genotyping 48 genetically distinctive individuals (plus-trees). Concerned loci were previously proven to be cross-compatible among various cultivars of cherry, hence, the method could have a broader utilization beyond to the field of forestry.
Our technique is based on post-PCR processing of 15 polymorphic SSRs loci amplified in three multiplex reactions with fluorescently labeled primers (6-FAM, VIC, PET and NED). All PCR products could be pooled and analyzed simultaneously (pseudo 15-plex). In order to make this approach feasible, we redefined sequences of several primers. Thus, utilizing modified primers provides non-overlapping amplicons of each fluorescent dye.

  • Korecký, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 21, Prague, Czech Republic ORCID http://orcid.org/0000-0001-7859-1750 E-mail: korecky@fld.czu.cz (email)
  • Bílý, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 21, Prague, Czech Republic ORCID http://orcid.org/0000-0001-5794-0907 E-mail: bily@fld.czu.cz
  • Sedlák, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamýcká 129, 165 21, Prague, Czech Republic ORCID http://orcid.org/0000-0001-8016-8900 E-mail: sedlak@af.czu.cz
  • Lstibůrek, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 21, Prague, Czech Republic ORCID http://orcid.org/0000-0002-6304-6669 E-mail: lstiburek@fld.czu.cz
article id 1573, category Research note
Marjut Turtiainen, Jari Miina, Kauko Salo, Juha-Pekka Hotanen. (2016). Modelling the coverage and annual variation in bilberry yield in Finland. Silva Fennica vol. 50 no. 4 article id 1573. https://doi.org/10.14214/sf.1573
Keywords: abundance; berry yield; generalised linear mixed model; Vaccinium myrtillus L.
Highlights: The highest bilberry coverage was found in mesic heath forests and fell forests; On peatlands the coverage was, on average, lower than on mineral soil sites; The approach introduced in this study to calculating annual berry yield indices is a promising way for estimating total annual bilberry yields over a given period of time.
Abstract | Full text in HTML | Full text in PDF | Author Info

The coverage of bilberry (Vaccinium myrtillus L.) was modelled as a function of site and stand characteristics using the permanent sample plots of the National Forest Inventory (NFI) (Model 1). The sample sites consisted of mineral soil forests as well as fells and peatland sites. Annual variation in the bilberry yield (Model 2) was analysed based on measurements over 2001–2014 in the permanent sample plots (so-called MASI plots) in various areas of Finland. We derived annual bilberry yield indices from the year effects of Model 2 and investigated whether these indices could be used to estimate annual variation in bilberry crops in Finland. The highest bilberry coverage was found in mesic heath forests and fell forests. On peatlands the coverage was, on average, lower than on mineral soil sites; the peatland sites with most bilberry coverage were meso-oligotrophic and oligotrophic spruce mires and oligotrophic pine mires. Our bilberry yield indices showed similar variation to those derived from the mean annual berry yields reported and calculated earlier using the MASI plots; the correlation between the indices was 0.795. This approach to calculating annual berry yield indices is a promising way for estimating total annual bilberry yields over a given period of time. Models 1 and 2 can be used in conjunction with the Miina et al.’s (2009) bilberry yield model when bilberry coverage, average annual yield and annual variation in the yield are to be predicted in forest planning.

  • Turtiainen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: marjut.turtiainen@uef.fi (email)
  • Miina, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Box 68, FI-80101 Joensuu, Finland E-mail: jari.miina@luke.fi
  • Salo, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, Box 68, FI-80101 Joensuu, Finland E-mail: kauko.salo@luke.fi
  • Hotanen, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Box 68, FI-80101 Joensuu, Finland E-mail: juha-pekka.hotanen@luke.fi
article id 1415, category Research note
Zorica Šarac, Tanja Dodoš, Nemanja Rajčević, Srdjan Bojović, Petar Marin, Jelena Aleksić. (2015). Genetic patterns in Pinus nigra from the central Balkans inferred from plastid and mitochondrial data. Silva Fennica vol. 49 no. 5 article id 1415. https://doi.org/10.14214/sf.1415
Keywords: genetic differentiation; genetic diversity; the Balkans; European black pine; chloroplast microsatellites; mitochondrial nad7 intron 1; haplotype network
Highlights: Seven populations of Pinus nigra from the central Balkans, representing four infraspecific taxa, were analyzed with chloroplast microsatellites and a mitochondrial locus; Molecular data failed to support infraspecific circumscriptions; Levels of genetic diversities/differentiation at both genomes were in the range of those reported in western Mediterranean populations of P. nigra; Iberian/African and Balkans’ populations share one mtDNA polymorphism and differ in three mutations.
Abstract | Full text in HTML | Full text in PDF | Author Info

Pinus nigra J.F. Arnold, European black pine, is a typical component of Mediterranean and sub-Mediterranean coniferous forests with highly fragmentary distribution. Western Mediterranean populations of this species have been studied genetically to date, while eastern populations from the central Balkans, which are larger and more abundant, are still genetically understudied. We analyzed seven populations of P. nigra representing all infraspecific taxa recognized within the central Balkans (subspecies nigra with varieties nigra and gocensis Đorđević; and subspecies pallasiana (Lamb.) Holmboe with varieties pallasiana and banatica (Endl.) Georgescu et Ionescu), with three chloroplast microsatellites (cpDNA SSRs) and one mitochondrial (mtDNA) locus. Although our molecular data failed to support circumscription of studied infraspecific taxa, we found that genetic patterns at both genomes are in accordance with those found previously in westward populations of this species, that is – exceptionally high levels of genetic diversity (HT = 0.949) and low genetic differentiation (GST = 0.024) at the cpDNA level, and moderate levels of genetic diversity (HT = 0.357) and genetic differentiation (GST = 0.358) at the mtDNA level. Based on genealogical relations of mtDNA types currently present in Balkans’ and Iberian/African populations, we inferred that the ancestral gene pool of P. nigra already harbored polymorphism at position 328 prior to the divergence to two lineages currently present in westward and eastward parts of the species range distribution. Subsequent occurrence of three mutations, which distinguish these two lineages, suggests their long-term isolation.

  • Šarac, University of Niš, Faculty of Sciences and Mathematics, Department of Biology and Ecology, Višegradska 33, 18000 Niš, Serbia E-mail: saraczorica@gmail.com (email)
  • Dodoš, University of Belgrade, Faculty of Biology, Institute of Botany and Botanical Garden “Jevremovac”, Studentski trg 16, 11000 Belgrade, Serbia E-mail: tanjadodos@bio.bg.ac.rs
  • Rajčević, University of Belgrade, Faculty of Biology, Institute of Botany and Botanical Garden “Jevremovac”, Studentski trg 16, 11000 Belgrade, Serbia E-mail: nemanja@bio.bg.ac.rs
  • Bojović, University of Belgrade, Institute for Biological Research “Siniša Stanković”, Boulevard Despota Stefana 142, 11060 Belgrade, Serbia E-mail: bojovic@ibiss.bg.ac.rs
  • Marin, University of Belgrade, Faculty of Biology, Institute of Botany and Botanical Garden “Jevremovac”, Studentski trg 16, 11000 Belgrade, Serbia E-mail: pdmarin@bio.bg.ac.rs
  • Aleksić, University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Vojvode Stepe 444a, P.O. Box 23, 11000 Belgrade, Serbia E-mail: aleksic_jelena@yahoo.com.au
article id 1136, category Research note
Håkan Lideskog, Back Tomas Ersson, Urban Bergsten, Magnus Karlberg. (2014). Determining boreal clearcut object properties and characteristics for identification purposes. Silva Fennica vol. 48 no. 3 article id 1136. https://doi.org/10.14214/sf.1136
Keywords: forestry; forest regeneration; clearcut obstacles; terrain description; terrain conditions; site properties
Highlights: We define the quantitative properties and qualitative characteristics of stumps, stones, slash, and roots, the most important objects interacting with machine activities after clearcutting; We develop a flowchart showing how a computer-aided system using clearcut object identification should be executed.
Abstract | Full text in HTML | Full text in PDF | Author Info
After clearcutting, machines traffic the clearcut conducting different silvicultural activities. Many objects on a forest clearcut (slash residues, stones, stumps and roots) may disturb e.g. site preparation and planting. This paper describes properties and characteristics of these objects. A flowchart was developed that describes a possible computer-aided system that identifies the objects, and ultimately, makes a machine avoid or target them. A system for obstacle identification creates conditions for further technical development and (semi)automation of e.g., site preparation, mechanized planting, and stump removal.
  • Lideskog, Division of Product and Production Development, Luleå University of Technology, SE-97187 Luleå, Sweden E-mail: hakan.lideskog@ltu.se (email)
  • Ersson, Department of Forest Biomaterials and Technology, SLU, SE-90183 Umeå, Sweden E-mail: back.tomas.ersson@slu.se
  • Bergsten, Department of Forest Biomaterials and Technology, SLU, SE-90183 Umeå, Sweden E-mail: urban.bergsten@slu.se
  • Karlberg, Division of Product and Production Development, Luleå University of Technology, SE-97187 Luleå, Sweden E-mail: magnus.karlberg@ltu.se
article id 1126, category Research note
Rebecka Mc Carthy, Per Magnus Ekö, Lars Rytter. (2014). Reliability of stump sprouting as a regeneration method for poplars: clonal behavior in survival, sprout straightness and growth. Silva Fennica vol. 48 no. 3 article id 1126. https://doi.org/10.14214/sf.1126
Keywords: Populus spp.; coppice regeneration; vegetative regeneration; short-rotation forestry
Highlights: Clonal differences were found in stump sprout survival; Clonal differences occurred in sprout straightness; It is uncertain if the ability to produce a high number of stump sprouts is beneficial.
Abstract | Full text in HTML | Full text in PDF | Author Info
The interest in poplars (Populus spp.) has increased globally as a result of the current incentive to expand the use of biomass for energy. So far, knowledge about poplar stump sprouting is generally poor. The objective of this study was to investigate poplar stump sprouting as regeneration method in harvested plantations. A 19-year-old poplar clonal test, including 23 different clones, on former arable land was harvested in the winter. After one year, stumps were assessed for sprout survival, sprout straightness, number of sprouts, sprout height and basal diameter. Differences between clones were found for survival and sprout straightness. Clonal differences were also found in mean size of sprouts (basal diameter and height). However, no differences were found between clones when comparing size of the tallest sprout or number of sprouts produced on stumps. This study indicates that stump sprouts from various poplar clones differ in survival, sprout straightness and mean growth, which should be taken into account when planning for the next tree generation. The study needs to be complemented with other studies to better assess sprouting characteristics for different clones.
  • Mc Carthy, Forestry Research Institute of Sweden, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden & Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: rebecka.mccarthy@skogforsk.se (email)
  • Ekö, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: Per.Magnus.Eko@slu.se
  • Rytter, Forestry Research Institute of Sweden, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden E-mail: lars.rytter@skogforsk.se
article id 37, category Research note
D. N. Avtzis, F. A. Aravanopoulos. (2011). Host tree and insect genetic diversity on the borderline of natural distribution: a case study of Picea abies and Pityogenes chalcographus (Coleoptera, Scolytinae) in Greece. Silva Fennica vol. 45 no. 1 article id 37. https://doi.org/10.14214/sf.37
Keywords: bark beetles; genetic bases; marginal populations; northern Greece; Norway spruce
Abstract | View details | Full text in PDF | Author Info
Picea abies (L.) Karst. and Pityogenes chalcographus constitute a commonly observed host tree–insect association in Eurasia, with the natural distribution of the bark beetle overlapping that of Norway spruce. The southernmost borderline of their distributions occurs in the Elatia forest (Mt. Rodopi, Greece), where these interacting organisms may experience severe conditions due to the effects of climate change. In order to assess the dynamics of this host tree–insect association, the genetic diversity of both organisms was studied. In contrast to previous studies, the assessment of molecular diversity was based on the same mitochondrial gene (Cytochrome Oxidase One) sequence for both host and pest. This analysis revealed a remarkably higher genetic diversity of P. chalcographus compared to that of P. abies, something that renders the insect capable not only of adapting to novel environmental conditions, but even of shifting to other host species. On the contrary, P. abies presented a narrow genetic base, a potential drawback at the southern-most region of the species natural distribution. Synthesizing the preliminary outcome for both organisms, it appears that P. chalcographus exhibits an evolutionary advantage over P. abies, something that should be considered when planning conservation strategies for the relict forest of Elatia.
  • Avtzis, Aristotle University of Thessaloniki, Laboratory of Forest Genetics and Tree Breeding, Thessaloniki, Greece E-mail: dimitrios.avtzis@gmail.com (email)
  • Aravanopoulos, Aristotle University of Thessaloniki, Laboratory of Forest Genetics and Tree Breeding, Thessaloniki, Greece E-mail: FAA@nn.fi

Category : Discussion article

article id 572, category Discussion article
Timo Kuuluvainen, Kaisu Aapala, Petri Ahlroth, Mikko Kuusinen, Tapio Lindholm, Tapani Sallantaus, Juha Siitonen, Harri Tukia. (2002). Principles of ecological restoration of boreal forested ecosystems: Finland as an example. Silva Fennica vol. 36 no. 1 article id 572. https://doi.org/10.14214/sf.572
Keywords: biodiversity; ecosystem management; disturbance dynamics; monitoring; heterogeneity; nature conservation; hierarchy
View details | Full text in PDF | Author Info
  • Kuuluvainen, Department of Forest Ecology, University of Helsinki, P.O.Box 27 FIN-00014, Finland E-mail: timo.kuuluvainen@helsinki.fi (email)
  • Aapala, Finnish Environment Institute, Expert Services Department, Nature Division, P.O. Box 140, FIN-00251 Helsinki E-mail: ka@nn.fi
  • Ahlroth, University Museum, Section of Natural History, P.O. Box 35, FIN-40351, Jyväskylä, Finland E-mail: pa@nn.fi
  • Kuusinen, Ministry of the Environment, Land Use Department, P.O.Box 380, FIN-00131 Helsinki, Finland E-mail: mk@nn.fi
  • Lindholm, Finnish Environment Institute, Expert Services Department, Nature Division, P.O. Box 140, FIN-00251 Helsinki E-mail: tl@nn.fi
  • Sallantaus, Pirkanmaa Regional Environment Centre, P.O. Box 297, FIN-33101 Tampere, Finland E-mail: ts@nn.fi
  • Siitonen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: juha.siitonen@metla.fi
  • Tukia, Finnish Environment Institute, Expert Services Department, Nature Division, P.O. Box 140, FIN-00251 Helsinki E-mail: ht@nn.fi

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