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Articles containing the keyword 'seed'

Category : Article

article id 5611, category Article
Arja Lilja, Timo Kurkela, Sakari Lilja, Risto Rikala.. (1997). Nursery practices and management of fungal diseases in forest nurseries in Finland. A review. Silva Fennica vol. 31 no. 1 article id 5611. https://doi.org/10.14214/sf.a8512
Keywords: Pinus sylvestris; Picea abies; forest nursery; Betula spp.; Finland; damping-off; grey mold; root dieback; scleroderris canker; pine twisting rust; seedlings; fungal diseases; Godronia multispora; Lophodermium needle cast; snow blights; birch rust; stem lesions of birch; leaf lesions of birch; Lophodermium pinastri; Botrytis cinerea; Melampsora pinitorqua; Melampsoridium betulinum
Abstract | View details | Full text in PDF | Author Info

The purpose of this article was to collate the literature on fungal diseases that occur on seedlings in forest nurseries. It describes the symptoms of the diseases, the infection pattern of each fungus and the possibilities of controlling the diseases. As background a short introduction is given on forests and nursery practices in Finland.

  • Lilja, E-mail: al@mm.unknown (email)
  • Kurkela, E-mail: tk@mm.unknown
  • Lilja, E-mail: sl@mm.unknown
  • Rikala., E-mail: rr@mm.unknown
article id 5577, category Article
Malgorzata Skrzypczynska. (1996). Relationship between Megastigmus suspectus Borr. size and Abies alba Mill. Seed size. Silva Fennica vol. 30 no. 1 article id 5577. https://doi.org/10.14214/sf.a9222
Keywords: seed size; seed; Abies alba; body size; Megastimus suspectus
Abstract | View details | Full text in PDF | Author Info

Investigation on the relationship between the size of the Megastigmus suspectus Borr. (Hymenoptera, Torymidae) and the size of Abies alba Mill. seeds from which those insects emerged was conducted. The examined insects (n = 46) originated from southern Poland, and were obtained from cones collected in 1993. M. suspectus thorax length was used as an index of adult insect size, because that was correlated with 8 other body measurements. In addition, the diameter of the emergence hole of this insect was measured. All data were log-transformed and analysed using regression analysis. There was no linear correlation between adult size and seed size, using either length of thorax or any of the other 8 body traits tested.

  • Skrzypczynska, E-mail: ms@mm.unknown (email)
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 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 5545, category Article
Jouni Siipilehto, Olavi Lyly. (1995). Weed control trials with fibre mulch, glyphosate and terbuthylazine in Scots pine plantations. Silva Fennica vol. 29 no. 1 article id 5545. https://doi.org/10.14214/sf.a9196
Keywords: Pinus sylvestris; herbicides; glyphosate; terbuthylazine; weed control; seedling stands; mulches
Abstract | View details | Full text in PDF | Author Info

The following treatments were compared in three Scots pine (Pinus sylvestris L.) reforestation areas on a scarified moist mineral-soil site in southern Finland, planted with 1+1 bareroot stock in spring 1987: (a) no weed control treatment; (b) mulching with a fibre slurry produced by mixing wastepaper with water and applied 1 cm deep to an area of 60 cm in diameter around the seedling soon after planting; (c) glyphosate (at 2 kg ha-1) sprayed on a 1 m2 spot around the seedling in early August 1987; (d) terbuthylazine (at 10 kg ha-1) applied as (c). Monitoring of the trials over a 4-year period between 1987–90 showed that none of the treatments reduced surface vegetation to an extent that would have benefited pine. The percentage cover development of the vegetation, dominated by Agrostis capillaris, Calamagrostis arundinaceae, Deschampsia flexuosa, Festuca ovina, Epilobioum angustifolium and Pteridium aquillinum, followed much the same pattern in all treatments, with (c) slightly favouring forbs. Survival of pine at the end of the study period was about 90%, with non-significant differences between treatments. Mulching and terbuthylazine treatment slightly reduced seedling height growth in the second year. Growth was better in glyphosate treatment than in terbuthylazine treatment in the lowest (<30%) and the highest (>60%) pre-treatment weed cover classes, and in the latter also better than in untreated control. Mulching gave variable results; at its best it provided also good control of weeds for several years, without, however, improving the initial development of pine in these trials.

  • Siipilehto, E-mail: js@mm.unknown (email)
  • Lyly, E-mail: ol@mm.unknown
article id 5542, category Article
Leena Ryynänen, Anneli Viherä-Aarnio. (1995). Growth, crown structure and seed production of birch seedlings, grafts and micropropagated plants. Silva Fennica vol. 29 no. 1 article id 5542. https://doi.org/10.14214/sf.a9193
Keywords: Betula pendula; silver birch; flowering; micropropagation; seedlings; seed orchards; seed production; grafts
Abstract | View details | Full text in PDF | Author Info

Growth, crown structure, flowering and seed production of silver birch (Betula pendula Roth) seedlings, grafts and micropropagated plants was compared during four years in a polythene greenhouse experiment. The growth of the seedlings was clearly the most vigorous and that of the grafts the weakest, the micropropagated plants being intermediate. The seedlings had the highest and the grafts the lowest number of branches before cutting the tops of the plants, but the differences between the material types were no more significant after cutting the tops. The grafts had significantly shorter and thinner branches than the seedlings and the micropropagated plants, whereas the differences in branch length and branch thickness between the latter two groups were not significant. The grafts started flowering at the age of two years, one year earlier than the other two types of material. At the age of four years the micropropagated plants had abundant seed production, about 75% of that of the seedlings and about two times higher than that of the grafts. Thus, the micropropagated plants can be used instead of grafts when establishing polythene greenhouse seed orchards of birch.

  • Ryynänen, E-mail: lr@mm.unknown (email)
  • Viherä-Aarnio, E-mail: av@mm.unknown
article id 5541, category Article
Anneli Viherä-Aarnio. (1994). Performance of micropropagated plants of silver birch (Betula pendula) in a field trial. Silva Fennica vol. 28 no. 4 article id 5541. https://doi.org/10.14214/sf.a9181
Keywords: Betula pendula; forestry; growth; mortality; seedlings; clones; tissue culture; clonal propagation
Abstract | View details | Full text in PDF | Author Info

Micropropagated and seed-borne plants of sliver birch (Betula pendula Roth) were compared for survival and growth in a field trial at the age of six years. Three clones for micropropagation were selected from open-pollinated progenies of selected southern Finnish plus trees at the age of 17 and 20. The three seed-borne lots were of southern Finnish stand origin. The best two lots of the experiment as regards the height and diameter growth at the age of six were the clones. The best of these differed significantly from the best-growing seed-grown lot. The weakest lot of the experiment was also a clone which was clearly slow-growing with a dense and bushy crown. Survival of the material was high (mean = 94%), and there was no damage caused by voles and elks, for example. The results clearly show that the selection of material for clonal propagation should be done carefully. The clones should also be tested for performance in the field before propagation on a large scale.

  • Viherä-Aarnio, E-mail: av@mm.unknown (email)
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 5538, category Article
Anneli Viherä-Aarnio, Leena Ryynänen. (1994). Seed production of micropropagated plants, grafts and seedlings of birch in a seed orchard. Silva Fennica vol. 28 no. 4 article id 5538. https://doi.org/10.14214/sf.a9178
Keywords: Betula pendula; seedlings; seed orchards; seed production; tissue culture; grafting
Abstract | View details | Full text in PDF | Author Info

Seed production of micropropagated plants, seedlings and grafts of Silver birch (Betula pendula Roth) in a polyethylene greenhouse experiment was followed for five years. The grafts started flowering and seed production at the age of two years, one year earlier than other two types of material. At the age of three the seed production of both micropropagated plants and seedlings was already more than two times higher than that of the grafts. Variation between the clones was high and plant type x clone interaction was significant. At the age of four, in 1993, seed production was high in all three types of material. Seed production of the micropropagated plants was two times higher than that of the grafts but about 75% of that of the seedlings. In 1994 seed production of all three plant types was very low, which shows large variation between different years. The early development of the plant material types suggests that micropropagated plants have higher seed production than grafts and could well be used instead of grafts in polythene greenhouse seed orchards.

  • Viherä-Aarnio, E-mail: av@mm.unknown (email)
  • Ryynänen, E-mail: lr@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 5530, category Article
Anna Saarsalmi, Erkki Lipas, Jouni Mikola, Teijo Nikkanen, Eira-Maija Savonen. (1994). Effect of fertilization on flowering and seed crop in Scots pine seed orchards. Silva Fennica vol. 28 no. 3 article id 5530. https://doi.org/10.14214/sf.a9170
Keywords: Pinus sylvestris; fertilization; germination; flowering; seed orchards; clones; seed crop; weight
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to obtain information needed in preparing more precise fertilization recommendations for seed orchards. The fertilization requirement was estimated on basis of soil and needle analyses, and by investigating the effects of different fertilization treatments on male and female flowering, size of seed crop and seed quality.

The study was carried out in two Scots pine (Pinus sylvestris L.) seed orchards in Southern Finland, one established on forest soil in 1971 and 1972, and the other on a peat field in 1974. 10 clones and 39 grafts from each clone were selected randomly from both orchards in autumn 1985. The treatments consisted of N, P and K in various combinations, micronutrients, wood ash and grass control. The orchards were fertilized in spring 1986.

There were statistically significant differences between the clones in both orchards as regards amount of flowers, size of the seed crop and seed quality. The annual variation in flowering and the size of the seed crop was also large. In general, the seeds from cones collected in October matured well and their germination percentage was high. The effects of fertilization on flowering, the size of seed crop and seed quality were small. It would appear that the size of the crop can be affected to a much greater extent by favouring clones with a high seed-producing capacity than through fertilization. Fertilization is unnecessary if the nutrient status of the soil is satisfactory.

  • Saarsalmi, E-mail: as@mm.unknown (email)
  • Lipas, E-mail: el@mm.unknown
  • Mikola, E-mail: jm@mm.unknown
  • Nikkanen, E-mail: tn@mm.unknown
  • Savonen, E-mail: es@mm.unknown
article id 5497, category Article
Pertti Pulkkinen. (1993). Frost hardiness development and lignification of young Norway spruce seedlings of southern and northern Finnish origin. Silva Fennica vol. 27 no. 1 article id 5497. https://doi.org/10.14214/sf.a15658
Keywords: Picea abies; provenance; stems; seedlings; frost resistance; lignification
Abstract | View details | Full text in PDF | Author Info

Seedlings from four Norway spruce (Picea abies (L.) H. Karst.) stands originating from areas with effective temperature sums ranging from 710 d.d. to 1,150 d.d. were raised under artificial light and temperature treatment. After a 10-week growing period the hardening process was started by subjecting the seedlings to +8°C night temperature and +15°C day temperature, and increasing the night length by 1.5 hour/week. Hardiness was measured by means of artificial freezing treatment (-10°C or -15°C), followed by visual estimation of the degree of needle injury. The stem height, lignification and bud development were measured before the freezing treatment. The amount of injury increased the more southern the origin of the tested material was. Furthermore, the proportion of non-lignified part of the seedling stem was negatively correlated with the latitude of the provenances. The proportion of seedlings with clearly visible buds was more than 90% in the northernmost entry and less than 1% in the southernmost one. The overall correlation coefficient between the needle injuries and the proportion of non-lignified part of the stem was rather high, but varied considerably from 0.3 in the northernmost material to over 0.6 in the southern provenances. According to the results, it seems to be possible to use growth characteristics as an indicator of frost hardiness at the provenance level.
The PDF includes an abstract in Finnish.

  • Pulkkinen, E-mail: pp@mm.unknown (email)
article id 5487, category Article
Maarit Kytö. (1992). Lygus bugs as agents of growth disorders in permethrin-treated pine seedlings in regeneration areas. Silva Fennica vol. 26 no. 4 article id 5487. https://doi.org/10.14214/sf.a15648
Keywords: Pinus sylvestris; growth disorders; seedlings; Lygus; permethrin; bud disorders
Abstract | View details | Full text in PDF | Author Info

The ability of Lygus bugs to cause growth disorders in permethrin-treated Scots pine (Pinus sylvestris L.) seedlings after planting was studied in two regeneration areas. There were three treatments: exposure of the seedlings to Lygus, mechanical protection of the seedlings from insects, and control seedlings. There were no significant differences in the rate of growth disorders between the treatments. The permethrin application protected the seedlings against Lygus bugs in the early summer, as well as when the bug abundance was low. The development of these seedlings, as well as the multiple-leadered and bushy seedlings on a third regeneration area, was followed for two years. Multiple leaders reduced height growth and bud number of a seedling, but caused marked losses in growth only when the seedlings still had multiple leaders the following year, or when they formed several, equally developed stems.
The PDF includes an abstract in Finnish.

  • Kytö, E-mail: mk@mm.unknown (email)
article id 5481, category Article
Pekka Nygren, Pertti Hari. (1992). Effect of foliar application with acid mist on the photosynthesis of potassium-deficient Scots pine seedlings. Silva Fennica vol. 26 no. 3 article id 5481. https://doi.org/10.14214/sf.a15642
Keywords: Pinus sylvestris; photosynthesis; nutrient deficiency; seedlings; acid deposition; potassium concentration
Abstract | View details | Full text in PDF | Author Info

The interactive effects of potassium deficit and foliar application with acid water (pH 5.5, 4.5, 4.0 and 3.0 given consecutively) on CO2 exchange rate of Pinus sylvestris L. seedlings was investigated in field conditions. No reduction of the CO2 exchange rate was observed in the seedlings supplied with sufficient potassium. Only the seedlings having the lowest needle K concentration (2.4 mgg-1) had an apparently low CO2 exchange rate before the applications with acid water. The CO2 exchange rate of most of the seedlings with low needle K concentration (3.9–6.0 mgg-1) decreased after the acid water application. The threshold acidity for the reduction varied between pH 4,0 and 3.0 depending on the needle K concentration. The reduction was more apparent at high irradiance. It was concluded that acid precipitation disturbs the CO2 exchange only in conditions of mineral nutrient deficit.

The PDF includes an abstract in Finnish.

  • Nygren, E-mail: pn@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
article id 5478, category Article
Seppo Kellomäki, Marja Kolström. (1992). Computations on the management of seedling stands of Scots pine under the influence of changing climate in southern Finland. Silva Fennica vol. 26 no. 2 article id 5478. https://doi.org/10.14214/sf.a15639
Keywords: Pinus sylvestris; forest management; models; Betula pendula; Scots pine; silver birch; simulation; climatic change; seedling stands
Abstract | View details | Full text in PDF | Author Info

Model computations on the management of Scots pine (Pinus sylvestris L.) at the seedling stage showed that a rising temperature due to the suggested climate change could increase the competition capacity of birch species (Betula pendula) more than Scots pine, whose growth could even decline during the course of a rise in temperature. A temperature rise could, thus, bring the time of removal of birches forward when aiming at Scots pine timber stands composed of these tree species. The increasing proportion of birches makes the removal of birches even more urgent and emphasizes the need for careful management of Scots pine stands under rising temperatures. The first thinning of Scots pine is generally brought forward; this is particularly the case when wide spacing is applied in planting. A furthrer rise in temperature magnifies the above patterns by reducing further the competitive capacity of Scots pine in relation to birches.
The PDF includes an abstract in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
  • Kolström, E-mail: mk@mm.unknown
article id 5476, category Article
Jukka Selander, Auli Immonen. (1992). Effect of fertilization and watering of Scots pine seedlings on the feeding preference of the pine weevil (Hylobius abietis L.). Silva Fennica vol. 26 no. 2 article id 5476. https://doi.org/10.14214/sf.a15637
Keywords: Pinus sylvestris; fertilization; pine weevil; water stress; Hylobius abietis; seedlings; feeding preference
Abstract | View details | Full text in PDF | Author Info

Two-year-old containerized Scots pine (Pinus sylvestris L.) seedlings, raised under different fertilization and watering regimes, were subjected to feeding preference tests with pine weevils (Hylobius abietis L.) in a bioassay. In the tests carried out with pairs of seedlings, the weevil preferred water-stressed seedlings to well-watered ones. In the case of well-watered seedlings, the weevil caused significantly more damage to NPK-fertilized seedlings than those given pure PK fertilization, or no fertilization at all. It is apparent that PK fertilization reduces, and water stress increases seedling susceptibility to weevil damage. The results support findings from field trials that water stress (planting shock) predisposes seedlings to weevil damage. Weevil resistance is discussed with respect to fertilization and water stress as determinants of seedling quality.

The PDF includes an abstract in Finnish.

  • Selander, E-mail: js@mm.unknown (email)
  • Immonen, E-mail: ai@mm.unknown
article id 5475, category Article
Jyrki Hytönen. (1992). Allelopathic potential of peatland plant species on germination and early seedling growth of Scots pine, silver birch and downy birch. Silva Fennica vol. 26 no. 2 article id 5475. https://doi.org/10.14214/sf.a15636
Keywords: Pinus sylvestris; Betula; seedling growth; seed germination; alleopathy
Abstract | View details | Full text in PDF | Author Info

The potential alleopathic inhibitive effects of aqueous extracts of 13 peatland plant species on germination, radicle and seedling growth of Scots pine (Pinus sylvestris L.), silver and downy birch (Betula pendula Roth., B. pubescens Ehrh.) were studied. Freshly cut plant parts were finely ground, mixed with distilled water and agitated. The proportions of fresh plant mass in the mass-based extracts varied within the range of 1, 5, 10 and 20% (w/w). The seeds were germinated in petri dishes moistened with the plant extracts. In a separate experiment growth of birch seedlings irrigated with the extracts was studied.

Ledum palustre, Vaccinium uliginosum and Empetrum nigrum extracts, and in certain experiments extracts of other species, inhibited the germination of Scots pine and birch seeds. Results from the different experiments were not, however, fully consistent. None of the low (1% w/w) extract concentrations had any effect on germination. Strong extract concentrations (20% w/w) inhibited germination of pine seedlings significantly. The extracts affected only slightly the growth of potted birch seedlings.

The PDF includes an abstract in Finnish.

  • Hytönen, E-mail: jh@mm.unknown (email)
article id 5467, category Article
E. K. Morgenstern, Y. S. Park. (1991). Breeding of Picea mariana (Mill.) B.S.P.: seed orchard and clonal approaches. Silva Fennica vol. 25 no. 4 article id 5467. https://doi.org/10.14214/sf.a15625
Keywords: Picea mariana; breeding; Canada; seed orchards; clonal forestry; breeding programs; backward selection
Abstract | View details | Full text in PDF | Author Info

During the past 30 years, genetics research has accumulated much information on black spruce (Picea mariana). The adoption of less intensive and faster plustree selection, establishment of seedling seed orchards and family selection significantly increased the rate of progress in improvement of the species. In New Brunswick this approach made it possible to obtain substantial quantities of seeds 10 years after the initiation of the program, and now all the seeds used in reforestation are derived from seed orchards.

Fourteen years after beginning the black spruce breeding program, second generation breeding is underway. The possibility of implementing alternative breeding strategies using ”breeding – cloning” procedures are explored for the advanced generation. Until somatic embryogenesis techniques become fully operational, ”backward selection” schemes and crossing in breeding halls followed by vegetative multiplication using serial rooted cuttings can be adopted. Larger genetic gains than those from conventional breeding are expected not only from the utilization of both additive and non-additive variances, but also from the elimination of inefficiencies of large conventional seed orchards.

  • Morgenstern, E-mail: em@mm.unknown (email)
  • Park, E-mail: yp@mm.unknown
article id 5463, category Article
Öje Danell. (1991). Survey of past, current and future Swedish forest tree breeding. Silva Fennica vol. 25 no. 4 article id 5463. https://doi.org/10.14214/sf.a15621
Keywords: Pinus sylvestris; Betula pendula; Picea abies; Sweden; Pinus contorta; seed orchards; forest tree breeding; breeding programmes
Abstract | View details | Full text in PDF | Author Info

The paper gives an introduction of the tree breeding program of Sweden that started in 1936 by the establishment of an association for the tree breeding. In 1967 the Institute of Forest Improvement was founded and it replaced the earlier association. The main species in the programme have been Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), lately also birch (mainly Betula pendula Roth.) and lodgepole pine (Pinus contorta). In addition, limited breeding has been done also with hybrid aspen (Populus tremula x P. tremuloides), oak (Quercus), larch (Larix), black spruce (Picea mariana) and a few other native and exotic species. The dominating initial effort has been to select plustrees in natural stands and use them for production of reforestation material. In addition, a considerable body of tests was built. The paper lists the status of breeding material of the different tree species and introduces the medium and short-term breeding programmes.

  • Danell, E-mail:
article id 5462, category Article
Wladyslaw Chalupka. (1991). Usefulness of hormonal stimulation in the production of genetically improved seeds. Silva Fennica vol. 25 no. 4 article id 5462. https://doi.org/10.14214/sf.a15620
Keywords: conifers; seed orchards; seed production; flowering regulation; growth regulation; gibberellins
Abstract | View details | Full text in PDF | Author Info

Application of growth regulators, primarily gibberellins, has become an efficient method of flowering regulation in many coniferous forest trees. In this paper some results are discussed with respect to various genetic processes in seed orchards. It is concluded that there are still several unsolved problems in the regulation of flowering in forest seed orchards. These problems are related to different genetic processes occurring in the seed orchards and they should be taken into account in endeavouring to produce genetically improved seeds. 

  • Chalupka, E-mail: wc@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 5457, category Article
Hans Roulund, Tore Skrøppa. (1991). Summary of main topics and conclusions from the meeting. Silva Fennica vol. 25 no. 4 article id 5457. https://doi.org/10.14214/sf.a15615
Keywords: progeny testing; seed orchards; meetings; IUFRO; breeding theory
Abstract | View details | Full text in PDF | Author Info

This paper summarises the main topics and conclusions from the joint meeting of two IUFRO working parties, S2.04-02, Breeding theory and progeny testing, and S2.02-16, Seed orchards, held in Tuusula, Finland on September 10–15, 1991. It concludes the main topics that need more research in these disciplines and future trends in the research.

  • Roulund, E-mail: hr@mm.unknown (email)
  • Skrøppa, E-mail: ts@mm.unknown
article id 5456, category Article
Veikko Koski. (1991). Biological systems in tree breeding. Silva Fennica vol. 25 no. 4 article id 5456. https://doi.org/10.14214/sf.a15614
Keywords: progeny testing; seed orchards; meetings; IUFRO; breeding theory
Abstract | View details | Full text in PDF | Author Info

This issue of Silva Fennica includes the presentations given in a joint meeting of two IUFRO working parties, S2.04-02, Breeding theory and progeny testing, and S2.02-16, Seed orchardsThe sessions were held in Tuusula, Finland on September 10–15, 1991.

  • Koski, E-mail:
article id 5452, category Article
Riitta Höyhtyä, Heikki Hänninen. (1991). Effect of photon flux density on bud dormancy release in Norway spruce seedlings. Silva Fennica vol. 25 no. 3 article id 5452. https://doi.org/10.14214/sf.a15610
Keywords: Picea abies; dormancy; seedlings; buds; light intensity; chilling requirement; annual habit; development
Abstract | View details | Full text in PDF | Author Info

The effect of photon flux density on bud dormancy release in two-year-old seedlings of Norway spruce (Picea abies (L.) H. Karst.) was examined. The seedlings were first chilled for 0–21 weeks under natural conditions and then forced in a warm greenhouse either in low (15 μEm-2s-1) or in high (300 μEm-2s-1) photon flux density. Occurrence of bud burst was observed in the forcing conditions, and the observations were used for estimating the cumulative frequency distribution of the chilling requirement for growth competence. The estimated distribution had greater variance in the low photon flux density than in the high photon flux density forcing. This finding suggests that unnaturally low photon flux densities during forcing may yield overestimates of the genetic within-population variation in the chilling requirement for growth competence.

The PDF includes an abstract in Finnish.

  • Höyhtyä, E-mail: rh@mm.unknown (email)
  • Hänninen, E-mail: hh@mm.unknown
article id 5442, category Article
Erkki Annila, Kari Heliövaara. (1991). Chemical control of cone pests in a Norway spruce seed orchard. Silva Fennica vol. 25 no. 2 article id 5442. https://doi.org/10.14214/sf.a15596
Keywords: Norway spruce; Picea abies; seed orchards; seed quality; pollen; chemical control; pesticides; cone pests; cone rust; pest control
Abstract | View details | Full text in PDF | Author Info

The effect of three pesticides containing either dimethoate (0.5% a.i.), permitrin (0.5%) or triadimephon (0.5%) on the cone pests and flowering biology of Norway spruce (Picea abies (L.) H. Karst.) was tested in a seed orchard in mid-May or in the beginning of June. The pesticide treatments significantly reduced infestation by Laspeyresia strobiella and Kaltenbachiella strobi only. Variation in the number of cones infested by both insects and cone rusts was high between the spruce clones. Generally, the pesticides did not affect flower viability, seed quality or seed germination, but reduced drastically the germination capacity of pollen in vitro. In practice, sufficient control cannot be achieved with concentrations or methods used in the present study.

The PDF includes an abstract in Finnish.

  • Annila, E-mail: ea@mm.unknown (email)
  • Heliövaara, E-mail: kh@mm.unknown
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 5410, category Article
Markku Nygren. (1990). Männyn ja kuusen siementen massan vaihtelusta. Silva Fennica vol. 24 no. 1 article id 5410. https://doi.org/10.14214/sf.a15562
English title: Variation in the seed mass of Scots pine and Norway spruce.
Original keywords: kuusi; mänty; lämpötila; sademäärä; siementen paino; siementen kypsyminen
English keywords: Pinus sylvestris; Picea abies; precipitation; temperature; seed mass; seed ripening
Abstract | View details | Full text in PDF | Author Info

Seed mass within any plant species is one of the least plastic components of plant structure. The aim of this study was to analyse the variation in the seed mass of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) in relation to three environmental factors: soil fertility, mean temperature and precipitation during seed filling period. Data published earlier on seed mass of these species on different sites and different years was used in the study.

The seed mass of both species was independent of soil fertility (forest type) but did vary between different years. It is hypothesized that if the seed-ripening summer is warmer than average, Scots pine seed mass tends to be smaller. In this study, seed mass varied independently of the amount of precipitation during the ripening summer. However, generalization of the results requires further study.

The PDF includes an abstract in English.

  • Nygren, E-mail: mn@mm.unknown (email)
article id 5406, category Article
Olavi Huuri. (1990). Leikattu paakkutaimi. Silva Fennica vol. 24 no. 1 article id 5406. https://doi.org/10.14214/sf.a15558
English title: The cut-block method for seedling production: birth of an idea.
Original keywords: kuusi; mänty; taimitarhat; leikattu paakkutaimi; paakkutaimet
English keywords: Pinus sylvestris; Picea abies; nurseries; cut-block seedling; container grown plants
Abstract | View details | Full text in PDF | Author Info

The author first introduced the cut-block seedling production method to Finland in 1969. The aim is to raise seedlings whose lateral roots do not become deformed as a result of a restricting container or other external pressure. The seedlings are raised in a large, fairly compact substrate block where the roots can freely develop in a normal fashion. The blocks are then cut up into individual cubes, each containing a seedling. The precise positioning of the sowing point permits mechanization of the work.

The PDF includes an abstract in English.

  • Huuri, E-mail: oh@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 5364, category Article
Urban Bergsten. (1988). Invigoration and IDS-sedimentation of Pinus sylvestris seeds from northern Finland. Silva Fennica vol. 22 no. 4 article id 5364. https://doi.org/10.14214/sf.a15521
Keywords: Pinus sylvestris; germination; Scots pine; northern Finland; seed quality; elimination of non-productive seeds; invigoration of seeds
Abstract | View details | Full text in PDF | Author Info

In Northern Finland as well as in Northern Sweden there is a shortage of high-quality Scots pine (Pinus sylvestris L.) seeds, mostly due to unsuitable temperatures during the development and maturation of cones and seeds. Methods have been developed for elimination of non-productive seeds and for invigoration of seeds. In the present work, these methods were tested on poorly developed seed lot from Rovaniemi, Northern Finland (66°15’–66°30’; 180 m a.s.l.). The seeds were conditioned using the following treatments:

1. PREVAC method (5 min, 97 kPa below atmospheric pressures) for removal of mechanically damaged seeds (7%)

2. Invigoration using incubation at controlled moisture content (30% f.w) and continuous air supply, for 14 days at 5°C.

3. Additional water supply for 16 hours at 5°C.

4. Drying in dehumidified air until a near maximum difference in density between viable and dead seeds was obtained

5. Separation in a sedimentation flume to achieve a gradient of fractions of different germination rate and capacity.

The treatments resulted in an improvement of germination percentage from 33 to about 95% and a reduction in mean germination time from 8.8 days to 6 days if the control and the best fractions (32% seeds) were compared.

  • Bergsten, E-mail: ub@mm.unknown (email)
article id 5360, category Article
Risto Rikala, Pasi Puttonen. (1988). Maan lämpötilan vaikutus kuivuusrasitukseen perustuvassa taimien laatutestissä. Silva Fennica vol. 22 no. 4 article id 5360. https://doi.org/10.14214/sf.a15517
English title: Effect of soil temperature in drought exposure-based test of seedling quality.
Keywords: Scots pine; soil temperature; root growth; seedling growth; shoot growth; drought; planting shock; desiccation
Abstract | View details | Full text in PDF | Author Info

The effect of root exposure on the shoot and root development of Pinus sylvestris (L.) seedlings was studied at two soil temperatures. Roots of bare-rooted three-year-old seedlings were exposed to the temperature of 32°C at relative humidity of 50–40% for 85, 155 and 270 minutes which corresponds to accumulated water pressure deficit of 24, 47 and 91 mbar·h, respectively. Thereafter, seedlings were grown for 65 days at the soil temperatures of 12 and 23°C. Drought exposures inhibited new root initiation, delayed shoot elongation, and reduced shoot and needle growth. The stronger the exposure the larger the proportion of needles from the lower part of current shoot that remained undeveloped. Low soil temperature increased the effect of exposures so that needle elongation and initiation of new root tips of seedlings in cold soil with the longest exposure were inhibited totally. Root growth assessments made in warm soil may overestimate the acclimation potential of planted seedlings.

The PDF includes an abstract in English.

  • Rikala, E-mail: rr@mm.unknown (email)
  • Puttonen, E-mail: pp@mm.unknown
article id 5354, category Article
Jan-Erik Nilsson. (1988). Variation in the rate of winter hardening of one-year-old plus-tree families of Scots pine raised in different enviroments. Silva Fennica vol. 22 no. 3 article id 5354. https://doi.org/10.14214/sf.a15511
Keywords: Pinus sylvestris; selection; breeding; seed orchards; cold acclimation; cold tolerance; full-sib families
Abstract | View details | Full text in PDF | Author Info

The effect of different environmental conditions (four outdoor localities and one greenhouse locality in Northern Sweden) on cold hardening of 29 one-year-old full-sib families from plus-trees of Scots pine (Pinus sylvestris L.) were studied by artificial freeze testing. Plants exposed to low night temperatures during August achieved faster cold hardening than plants raised in milder localities. The family ranking for rate of winter hardening was consistent among outdoor localities if freeze testing was performed at times when plants from different localities had attained similar levels of cold hardiness. However, significant family x locality interactions were obtained when plants from the outdoor localities were freeze tested on the same occasion. Freeze damage was positively correlated with plant height but not correlated with dry matter content in the autumn. Freezing damage of greenhouse raised plus-tree families was uncorrelated with damage of plants raised outdoors. Possible implications for hardiness breeding are suggested.

The PDF includes an abstract in Finnish.

  • Nilsson, E-mail: jn@mm.unknown (email)
article id 5352, category Article
Lars Christersson, Heinrich A. von Fircks. (1988). Injuries to conifer seedlings caused by simulated summer frost and winter desiccation. Silva Fennica vol. 22 no. 3 article id 5352. https://doi.org/10.14214/sf.a15509
Keywords: Pinus sylvestris; Picea abies; Picea mariana; conifers; frost damage; Sweden; Pinus contorta; seedlings; cold tolerance; frost hardiness in growing phase; winter desiccation
Abstract | View details | Full text in PDF | Author Info

Visible frost damage to forest trees in Sweden seldom occurs in winter but is frequent in late spring, summer and early autumn. Frosts are frequent in all seasons in various parts of Sweden, even in the southernmost part (lat. 56°, N) and temperatures may be as low as -10°C even around mid-summer. Ice crystal formation within the tissues, which in most seedlings takes place at around -2°C, causes injury, not the sub-zero temperatures themselves.

The apical meristem, the elongated zone, and the needles of seedlings of Picea abies (L.) H. Karst. in a growing phase were damaged at about -3°C and those of Pinus sylvestris L. at about -6°C. Other species of the genus Pinus were tested and most were found to be damaged at about -6°C, with some variations. Picea species tested were damaged at about -3°C to -4°C.

A method has been designed to compare the response of different species to winter desiccation, which occurs under conditions of (1) low night temperature, (2) very high irradiation and increase in needle temperature during the photoperiod, (3) frozen soil, and (4) low wind speed. There were differences in response to winter desiccation between pine and spruce species. Seedlings of Pinus contorta tolerated these winter desiccation conditions much better than those of P. sylvestris or Picea abies. Picea mariana was the least tolerant of the species tested.

The PDF includes an abstract in Finnish.

  • Christersson, E-mail: lc@mm.unknown (email)
  • Fircks, E-mail: hf@mm.unknown
article id 5320, category Article
Veikko Hintikka. (1987). Germination ecology of Galeopsis bifida (Lamiaceae) as a pioneer species in forest succesion. Silva Fennica vol. 21 no. 3 article id 5320. https://doi.org/10.14214/sf.a15477
Keywords: prescribed burning; Galeopsis bifida; germination ecology; pioneer species; forest succession; release of seed dormancy; clear-cut area
Abstract | View details | Full text in PDF | Author Info

The occurrence of Caleopsis bifida on clear-cut and burned forest soil and its disappearance in 4–6 years after disturbance is attributed to its germination ecology. Initially the seeds are dormant 96–100% and remain dormant in nylon gaze bags in different types of forest humus layers at least 10 years. Dormancy is released in laboratory (1) by treatment of 100 ppm aqueous solution of GA3, (2) by heating the dormant seeds to 40–55°C for 1–5 h, and (3) by 1% KNO3 solution. It is concluded that conditions in clear-cut and burned areas favour germination of seeds in regard to temperature and content of nitrates in contrast to humus of closed vegetation where the seeds remain dormant.

The PDF includes an abstract in Finnish.

  • Hintikka, E-mail: vh@mm.unknown (email)
article id 5312, category Article
Timo Pukkala. (1987). Siementuotannon vaikutus kuusen ja männyn vuotuiseen kasvuun. Silva Fennica vol. 21 no. 2 article id 5312. https://doi.org/10.14214/sf.a15469
English title: Effect of seed production on the annual growth of Picea abies and Pinus sylvestris.
Original keywords: kuusi; mänty; Lappi; siemensato; sädekasvu; kesäpuu
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; Finland; latewood; Lapland; radial growth; seed crop
Abstract | View details | Full text in PDF | Author Info

The study material consisted of 13 rather old Norway spruce (Picea abies (L.) H. Karst.) and 17 Scots pine (Pinus sylvestris L.) stands located in different parts of Finland. In each stand the seed crops, radial growth and amount of latewood were measured during a period of about ten years. Seed production reduces the radial growth of spruce and pine in the year of seed maturing. In Southern and Central Finland also the proportion of latewood is reduced. Seed production accounts for about 14% of the variation in radial growth of a spruce stand growing in Lapland, and 27% in other parts of Finland. In pine stands the seed crop explains 19% of the variation in radial growth in Lapland, and only 7% in the rest of Finland. In spruce stands an average seed crop reduces radial growth by 14% in Lapland and 5% in the rest of the country. An abundant seed production causes a reduction of about 20%. In southern parts of Finland, the proportion of latewood is reduced by 5% in an average seed year and by 24% in a good seed year. In pine stands an average seed crop decreases the width of annual ring by 5%, and a good seed crop by 15%. Outside Lapland, also the proportion of latewood is reduced: in an average seed year by 5%, and in a good seed year by 16%. The reduction in volume growth of spruce stands due to an average seed crop was estimated to be about 10% in Lapland, and 6% in other parts of Finland. A prolific seed production causes a reduction of 20%. In old pine stands the reduction is 5% in an average seed year, and 15% in a good seed year.

The PDF includes an abstract in English.

  • Pukkala, E-mail: tp@mm.unknown (email)
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 5305, category Article
Timo Pukkala. (1987). Simulation model for natural regeneration of Pinus sylvestris, Picea abies, Betula pendula and Betula pubescens. Silva Fennica vol. 21 no. 1 article id 5305. https://doi.org/10.14214/sf.a15462
Keywords: Pinus sylvestris; Betula pendula; Picea abies; germination; Betula pubescens; mortality; seed crop; computer model; stochastic simulation; birth model
Abstract | View details | Full text in PDF | Author Info

In the model the regeneration process is derived into three subprocesses: birth, growth and mortality of seedlings. The main emphasis is on the birth process where the following phases are simulated: seed crop, quality of seeds, maturity of seeds, predation of seeds and germination. The parameters are based on data published in Finland. Part of the parameters are obtained directly from the investigations and part is proposed by the author. The model can be calibrated by changing parameter values. The simulation is made with the help of random numbers which have the same means as the estimates and the same distributions as the residuals of the equations used in simulation. The time step of the model is one year. The number of emerged seedlings in one year is obtained by multiplying the seed crop with the probabilities that the seed passes different phases of the birth process. Because of stochasticity the regeneration period is simulated several times. From the results it is possible to evaluate the risk and succeeding probability of the regeneration. The main drawbacks of the simulation method are the lack of empirical parameters and the difficulty of testing. The model could be further developed by including spatiality into the model.

The PDF includes an abstract in Finnish.

  • 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 5262, category Article
Markku Nygren. (1986). Männyn siementen syyskeräys. Silva Fennica vol. 20 no. 1 article id 5262. https://doi.org/10.14214/sf.a15441
English title: Autumn harvested Scots pine seeds: the effect of cone storage and germination conditions on germination capacity.
Original keywords: mänty; itävyys; dormanssi; siemenkeräys; lepotila; käpyjen varastointi
English keywords: Pinus sylvestris; Scots pine; germination capacity; seed dormancy; cone storage
Abstract | View details | Full text in PDF | Author Info

Six seed collections were made in September–December 1984 in a natural Scots pine (Pinus sylvestris L.) stand in Southern Finland. The seeds were germinated immediately after the cone collection and three photoperiods (0.8 and 24 hours) were used in germination tests.

The seeds collected in September and October possessed relative dormancy, i.e. they did not germinate in darkness and at 10°C. Later in November and December the seeds were capable to germinate in darkness and at low temperature also. The gradual change in germination capacity is attributed to chilling temperatures in natural environments or in cone storage.

The PDF includes a summary in English.

  • Nygren, E-mail: mn@mm.unknown (email)
article id 5252, category Article
Kari Löyttyniemi. (1985). On repeated browsing of Scots pine saplings by moose (Alces alces). Silva Fennica vol. 19 no. 4 article id 5252. https://doi.org/10.14214/sf.a15431
Keywords: Pinus sylvestris; Scots pine; Finland; Alces alces; moose; seedling damages; browsing damage; elks
Abstract | View details | Full text in PDF | Author Info

The size, nutrient contents and terpene composition of needles of Scots pine (Pinus sylvestris L.) saplings untouched and repeatedly browsed by the moose (Alces alces L.) were compared. Material was collected from a 14-years old and 2.5 m high pine stand in Bromarv, Southern Finland. The average length and fresh and dry weight of the needles were measured, and nutrient content (N, P, K, Ca, Mg, B, Cu) was determined.

The needles of repeatedly browsed pines became long and robust. There was, however, no difference between the dry matter percentage between the needles. The average nitrogen content was higher in the rebrowsed trees. Nitrogen content is, however, not directly correlated with the palatability of pine needles. Even phosphorus and boron content were higher in the damaged trees. No difference was found in Ca, K, Mg and Cu contents of the browsed and control pine saplings.

The PDF includes a summary in Finnish.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 5249, category Article
Jari Parviainen. (1985). Istuttamalla perustetun nuoren männikön, kuusikon, siperianlehtikuusikon ja rauduskoivikon kasvu. Silva Fennica vol. 19 no. 4 article id 5249. https://doi.org/10.14214/sf.a15428
English title: Growth of young Scots pine, Norway spruce, siberian larch and silver birch plantations.
Original keywords: kuusi; istutus; taimikko; läpimitan kasvu; tilavuuskasvu; pituuskasvu; rauduskoivu; siperianlehtikuusi; kasvunopeus
English keywords: Betula pendula; Picea abies; height growth; planting; diameter growth; volume growth; seedling stands; Larix sibirica
Abstract | View details | Full text in PDF | Author Info

Early growth of four different tree species (Pinus sylvestris L., Picea abies (L.) H. Karst., Larix sibirica Ledeb and Betula pendula Roth) 16–23 years after planting were compared in a field experiment of 16 square plots established on a stony, grove-like upland (Oxalis-Myrtillus forest type) in Southern Finland. This study gives additional results to the publication Folia Forestalia 386/1979.

At this early stage, the growth of the spruce stand was clearly slower than that of the other species for all parameters to be measured (height, diameter, and volume growth). Height growth was most rapid in the silver birch stand and diameter growth in the larch stand. No clear differences were found in the mean volume of the 100 thickest trees in the stand between the larch and silver birch.

The PDF includes a summary in English.

  • Parviainen, E-mail: jp@mm.unknown (email)
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 5195, category Article
Matti Rousi. (1983). Susceptibility of pine to mammalian herbivores in northern Finland. Silva Fennica vol. 17 no. 4 article id 5195. https://doi.org/10.14214/sf.a15178
Keywords: Pinus sylvestris; fertilization; Scots pine; Alces alces; moose; forest damage; seedling damages; arctic hare; Lepus timidus; root vole; Microtus oeconomus; bank vole; Microtus agrestis
Abstract | View details | Full text in PDF | Author Info

An inventory of Scots pine (Pinus sylvestris L.) graft collection in Kolari (67°15’ N, 23°45’ S) showed that severe damage by arctic hare (Lepus timidus L.), root and bank vole (Microtus oeconomus Pallas and M. agrestis L.) and moose (Alces alces L.) was done to grafts in size and in rather poor condition. Furthermore, the damage by arctic hare was dependent on the dry matter content of the needles. Another inventory in a fertilization experiment in a pine pole-stage forest showed that nitrogen fertilization increased the damage by arctic hare. On the basis of the present results, an assumption was made that the formation of repellent substances against herbivorous mammals is connected with wintering process of northern pines.

The PDF includes a summary in Finnish.

  • Rousi, E-mail: mr@mm.unknown (email)
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 5163, category Article
Leo Heikurainen. (1982). Ojitusalueiden taimistojen kehityksestä vuosina 1964-68 toimeenpannun suometsäkilpailun koealojen valossa. Silva Fennica vol. 16 no. 3 article id 5163. https://doi.org/10.14214/sf.a15078
English title: Development of seedling stands on drained peatlands in Southern Finland.
Original keywords: metsitys; ojitusalueet; kasvu; lannoitus; ojitetut suot; taimikot
English keywords: afforestation; drained peatlands; Finland; growth; seedling stands; fertilizing
Abstract | View details | Full text in PDF | Author Info

The aim of the paper was to describe the development of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seedling stands on drained peatlands and to find out the principal factors influencing their growth. The material under survey consists of 180 sample plots distributed from southern coast of Finland to the Polar Circle.

The most important growth factors have been the accumulated temperature sum, site quality, drainage intensity and silvicultural condition, such as the density of the stand, the proportion of birch in the stand, and the amount of possible shelterwoods. The influence of these factors, and to some extent the influence of fertilizing, and the disturbing effects of some forest damages, such as frost, growth disturbances and elk damages were investigated. Comparisons of the development in the seedling stands on drained peatlands with the known development of seedling stands in mineral soils were made.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@mm.unknown (email)
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 5123, category Article
Heljä-Sisko Katainen, Seppo Kellomäki. (1981). Happaman veden vaikutus männyn taimiin. Silva Fennica vol. 15 no. 3 article id 5123. https://doi.org/10.14214/sf.a15064
English title: Effect of foliar application of dilute sulphuric acid on Scots pine seedlings.
Original keywords: mänty; taimet; pituuskasvu; neulasvauriot; fotosynteesi; happamuus; hapan sade
English keywords: Pinus sylvestris; photosynthesis; Scots pine; height growth; acidity; seedlings; needle damages; acid rain
Abstract | View details | Full text in PDF | Author Info

Needle damages, transpiration, photosynthesis and needle and stem height growth of Scots pine (Pinus sylvestris L.) seedlings treated with dilute sulphuric acid were studied. The acidity of the solution was pH 3. Application of a dilute solution of sulphuric acid equivalent to the normal amount of precipitation occurring during the growing season damaged the surface of two-year-old needles but not that of the current-year needles. A reduction in the photosynthetic rate of 10–30% was observed compared with the untreated seedlings. Transpiration of the seedlings was not affected by the treatment. Needle growth and stem height growth of the seedlings growing on a substrate representing poor sandy soil were reduced. Increased needle growth and stem height growth were characteristic for the seedlings growing on substrate representing fertile moraine.

The PDF includes a summary in English.

  • Katainen, E-mail: hk@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
article id 5086, category Article
Jussi Meriluoto. (1980). MCPA- ja 2,4,5-T-herbisidien käyttökelpoisuus taimiston hoidossa. Silva Fennica vol. 14 no. 4 article id 5086. https://doi.org/10.14214/sf.a15027
English title: Applicability of MCPA- and 2,4,5-T-herbicides in sapling stand management.
Original keywords: mänty; koivu; herbisidit; taimikonhoito; haapa; vesakontorjunta
English keywords: Populus tremula; Pinus sylvestris; Betula; Scots pine; herbicides; herbicide; seedling stands; aspen; brushkiller; shrub clearance
Abstract | View details | Full text in PDF | Author Info

The applicability of MCPA- and 2,4,5-T-herbicides for use in the management of sapling stands and the possibilities of carrying out foliar spraying at an earlier date than at precent with smaller doses of the active ingredient were examined in this study. The results were obtained from foliage spraying experiments carried out in Central Finland in summer 1976. MCPA and 2,4,5-T were as effective as each other against deciduous tree species. However, MCPA was slightly more effective against aspen (Populus tremula L.) than 2,4,5-T. The spraying date had no effect on the mortality rate of aspen or birch (Betula pendula Roth and B. pubescens Ehrh.) There were only very slight differences between the results for different dosage levels. The damage caused to Scots pine (Pinus sylvestris L.) was very slight. The temperature conditions prevailing during spraying affected spraying effectiveness in such way that the mortality rate decreased during cold period.

The PDF includes a summary in English.

  • Meriluoto, E-mail: jm@mm.unknown (email)
article id 5076, category Article
Veikko Koski. (1980). Minimivaatimukset männyn siemenviljelyksille Suomessa. Silva Fennica vol. 14 no. 2 article id 5076. https://doi.org/10.14214/sf.a15017
English title: Minimum requirements for seed orchards of Scots pine in Finland.
Original keywords: mänty; siemenviljelmät; kloonit; siemenviljely; laatuvaatimukset
English keywords: Pinus sylvestris; Scots pine; Finland; seed orchards; clones; requirements
Abstract | View details | Full text in PDF | Author Info

In order to be recorded in the national list of untested seed orchards, set by law, a seed orchard must attain certain objectives. It is impossible to define universal requirements for all categories of seed orchards of all species. The present paper suggests minimum requirements for a clonal region seed orchards of Pinus sylvestris L in Finland. The clonal composition as well as factors influencing on the mating pattern have been given precise numerical threshold values. To be approved the seed orchard must fulfil all the requirements at the same time. The goal is to control the genetic superiority of the forest reproductive material obtained from registered untested seed orchards.

The PDF includes a summary in English.

  • Koski, E-mail: vk@mm.unknown (email)
article id 5071, category Article
Martti Ryynänen. (1980). X-ray radiography of ageing Scots pine seeds. Silva Fennica vol. 14 no. 1 article id 5071. https://doi.org/10.14214/sf.a15012
Keywords: Pinus sylvestris; germination; Scots pine; storage; seeds; quality of seeds; X-ray radiography; X-ray contrast radiography
Abstract | View details | Full text in PDF | Author Info

Soft X-ray radiation (Grenz rays) has been used in the X-ray radiography of seeds. It is based on the principle that the different parts of the seed absorb X-rays to a slightly varying extent. Empty seeds and empty regions in the seeds appears as dark areas on the film. X-ray radiography without staining and X-ray contrast radiography were compared to study the stored seeds of Scots pine (Pinus sylvestris L.). The results were compared with the results of germination in a Jacobsen germinator according to ISTA norms.

Normal X-ray radiography gave too good estimates of germinative capacity of the seeds, and was shown to suit only when it is used to study fully ripe seeds which have recently been collected in an undamaged condition. The results of X-ray contrast radiography when barium chloride was used as the stain, however, followed closely the germination results.

The PDF includes a summary in Finnish.

  • Ryynänen, E-mail: mr@mm.unknown (email)
article id 5070, category Article
Olavi Luukkanen, Stig Johansson. (1980). Flower induction by exogenous plant hormones in Scots pine and Norway spruce grafts. Silva Fennica vol. 14 no. 1 article id 5070. https://doi.org/10.14214/sf.a15011
Keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; flowering; seed orchards; growth hormones; gibberellin; kloonit
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to establish whether hormone treatments would promote flowering in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) grafts under Finnish conditions. Also, an attempt was made to test the efficiency of hormones as well as the variation in response among different clones. Six Scots pine and six Norway spruce clones were selected in each seed orchard based on their flowering intensity, and treated with growth hormones (GA, NAA) of different dosages by spraying. Flowering was observed one year after the treatments.

None of the treated or untreated spruce grafts flowered. However, poor flowering in the natural stands indicated that the environmental conditions during the previous years did not favour flowering. On the other hand, a distinct increase in flowering in Scots pine was observed as a result of spraying with hormone solutions. Treatments with gibberellin had a distinct promoting effect both on male and female flowering in the Scots pine grafts, although the responses varied between the different hormones or clones. The relative effect was generally stronger in male flowering.

The PDF includes a summary in Finnish.

  • Luukkanen, E-mail: ol@mm.unknown (email)
  • Johansson, E-mail: sj@mm.unknown
article id 5069, category Article
Jouni Mikola. (1980). The effect of seed size and duration of growth on the height of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) provenances and progenies at the nursery stage. Silva Fennica vol. 14 no. 1 article id 5069. https://doi.org/10.14214/sf.a15010
Keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; height growth; provenance; seed size; annual growth rhythm
Abstract | View details | Full text in PDF | Author Info

In this paper the connection between seed weight and amount and duration of growth are studied at the progeny level within stands or climatically uniform areas, and at the provenance level within larger geographic areas. The material consists of materials of several experiments in the nursery of Maisala in Southern Finland in 1971–76. The origins of the plant material used in the different experiments ranged from progenies of individual Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies (L.) H. Karst.) trees to provenance selections covering almost the whole natural range of these species.

The effect of seed weight on plant height is strongest immediately after germination and subsequently decreases steadily, when the genetic growth properties of the plants themselves become effective. The effect is usually visible at least until the end of the 1st growing season. This relationship varies considerably depending on the material studied. The connections between the duration and the amount of height growth also proved to differ according to the nature of genetic variation. In wide selection of provenances, which show clear genetic differentiation in annual growth rhythm. The variation in the duration of growth accounts for most of the differences in total height growth. At the individual and family level or between provenances of a limited area, there seems to be no clear connection between the duration and the amount of growth. It seems that the duration of the annual growing period is a genetic property, which is not affected by seed weight.

The total height alone in 1-year old test material grown in a greenhouse had hardly any value in the forecasting of growth capacity. The growth differences were caused mainly by the variation in seed size and growth rate differences during the growing period.

The PDF includes a summary in Finnish.

  • Mikola, E-mail: jm@mm.unknown (email)
article id 5067, category Article
Veikko Koski. (1980). On the variation of flowering and seed crop in mature stands of Pinus sylvestris L. Silva Fennica vol. 14 no. 1 article id 5067. https://doi.org/10.14214/sf.a15008
Keywords: Pinus sylvestris; Scots pine; flowering; capacity; periodicity; seed crop
Abstract | View details | Full text in PDF | Author Info

The paper discusses the variation of flowering and seed crop of Scots pine (Pinus sylvestris L.) stands based on literature published in Finland. According to the studies, the list of good seed years given by different authors do not completely match, and no essentially new about the periodicity of the seed crop or the causes of variation has been found. The difficulty in classification of the seed crops in different years in different stands and locations can be handled through the concept of capacity. It is suggested in the paper that to be able to compare the occurrence of good flowering and seed years of different stands and localities, a case exceeding 50% of the capacity is described as abundant, and a case exceeding 75% as very heavy.

The PDF includes a summary in Finnish.

  • Koski, E-mail: vk@mm.unknown (email)
article id 5066, category Article
J. P. Efimov. (1980). Some results on the regularities of seed crops in Scots pine seed orchards. Silva Fennica vol. 14 no. 1 article id 5066. https://doi.org/10.14214/sf.a15007
Keywords: Pinus sylvestris; Scots pine; tree breeding; seed orchards; Symposiums; Soviet Union; USSR; seed crop; cone yield
Abstract | View details | Full text in PDF | Author Info

Establishment of seed orchards to produce genetically improved seed started in the USSR in the 1960’s. The aim is that within 10–15 years the total seed production will reach 50% of the seed used. The paper describes seed production in seed orchards of Scots pine (Pinus sylvestris L.) in the forest-steppe of the European part of the USSR. The orchards have been established either by grafting or by planting of seedlings originating from plus trees. The grafts begin flowering relatively early, however, only at the age of 8–10 years seed crops become relatively regular and abundant. The cone yield in young seed orchards have great variability, and the yield of cones varies between clones. Cone yield does not always correlate with a good seed yield. One of the reasons for high amount of empty seeds is the difference in the periods of flowering between the clones.

The seed crops can be improved by establishing optimal conditions for the growth of the trees. Also, when a seed orchard is founded, the peculiarities of the generative activities of the clones and their reactions to changes in the environmental conditions must be taken account by taking an individual and selective measure approach to improvement measures. The orchards can be established with clones for their genetic combining ability and their requirements for the stimulation of seed-bearing.

The PDF includes a summary in Finnish.

  • Efimov, E-mail: je@mm.unknown (email)
article id 5064, category Article
E. P. Prokazin. (1980). Geographic variation in forest trees. Silva Fennica vol. 14 no. 1 article id 5064. https://doi.org/10.14214/sf.a15005
Keywords: Scots pine; tree breeding; seed orchards; forest research; Symposiums; Soviet Union; USSR; provenience experiments
Abstract | View details | Full text in PDF | Author Info

Planting of forest trees takes place in USSR on millions of hectares but without permanent forest seed bases having yet been established in every region of the country. Consequently, local seed does not suffice the need, and it is necessary to secure it from other geographical regions. To avoid negative consequences of seed transfer it is necessary to study geographic variation of the genetic characteristics of forest trees and construct scientifically based division into seed zones. Geographic transfer of seed can also be regarded as a breeding measure. A large research program is being carried out in the USSR on the subject. Most of the existing trials are provenience tests of Scots pine (Pinus sylvestris L.). Over 2,000 hectares of new provenience experiments is to be established in near future.

The PDF includes a summary in Finnish.

  • Prokazin, E-mail: ep@mm.unknown (email)
article id 5060, category Article
A. I. Novoselceva. (1980). On the application of forest genetics and forest tree breeding research to practical forest seed production. Silva Fennica vol. 14 no. 1 article id 5060. https://doi.org/10.14214/sf.a15001
Keywords: tree breeding; tree species; seed orchards; Symposiums; Soviet Union; USSR; seed collection
Abstract | View details | Full text in PDF | Author Info

The development of the scientific basis for the production of high-quality seed led to the introduction of a large part of the research findings in forest genetics and forest tree breeding into practical forest seed production in the USSR. Since 1971, work has begun in forest enterprises on the establishment of a permanent seed supply for the main tree species – Pinus sylvestris, Picea ssp., Larix ssp. Quercus robur, Haloxylon ssp. and nut trees.

The basis for forest tree improvement is a gene pool which is built up using mass and individual selection of valuable forms in natural populations. In accordance with a long-term programme up to 1990, an inventory of 13.2 million ha of the best high-productive stands has been carried out for breeding purposes in the state forests. About 7,000 ha of plus stands have been selected, and a total of 9,453 ha of seed orchards and 141,253 ha of seed collection stands have been established. The first stage of the programme is planned to be complete in 1980, and in the second stage clonal high-quality seed orchards will be established.

The PDF includes a summary in Finnish

  • Novoselceva, E-mail: an@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 5022, category Article
Jukka Selander, Paavo Kalo. (1979). Männyn taimen pihkan monoterpeenien vaikutuksista tuhonkestävyyteen tukkimiehentäitä, Hylobius abietis L. ( Coleoptera, Curculionidae) vastaan. Silva Fennica vol. 13 no. 2 article id 5022. https://doi.org/10.14214/sf.a14876
English title: Evaluation of resistance of Scots pine seedlings against the large pine weevil Hylobius abietis L. in relation to their monoterpene composition.
Original keywords: hyönteistuhot; mänty; taimet; tukkimiehentäi; resistenssi; monoterpeeni
English keywords: Pinus sylvestris; Scots pine; Hylobius abietis; seedlings; insect damages; large pine weevil; monoterpenes; insect resistance
Abstract | View details | Full text in PDF | Author Info

The development of Scots pine (Pinus sylvestris L.) seedlings and damage caused by Hylobius abietis L. (Coleoptera, Curculionidae) were studied during a three-year period. Olfactory responses of H. abietis was studied in laboratory with several volatile oils isolated from different kinds of P. sylvestris seedlings. Resistance of seedlings against H. Abietis was evaluated in terms of their monoterpene composition. Three aspects of resistance (preference, antibiosis and tolerance) were evaluated separately. Seedling chemotype was found to be associated with these aspects of host resistance on only minor scale. Discussion was attached to a further search for host resistance arising from other properties and constituents of oleoresin. Height growth of the seedlings recovering from weevil damage was 86–91% compared to healthy seedlings.

The PDF includes a summary in English.

  • Selander, E-mail: js@mm.unknown (email)
  • Kalo, E-mail: pk@mm.unknown
article id 5021, category Article
Antti Koskimäki, Pertti Hari, Markku Kanninen, Seppo Kellomäki. (1979). Inherent growth rythm of some Larix-species grown in a plastic greenhouse. Silva Fennica vol. 13 no. 1 article id 5021. https://doi.org/10.14214/sf.a14875
Keywords: nursery; height growth; larch; seedlings; Larix decidua; Larix sibirica; Larix laricina; greenhouse cultivation; Larix leptolepsis; growth rythm
Abstract | View details | Full text in PDF | Author Info

The daily height growth rate of several larch species and progenies (Larix decidua, Larix sibirica, Larix laricina, Larix leptolepis) grown in a plastic greenhouse and in the open was measured. The growth pattern indoors was completely different compared with the normal outdoor growth pattern. The onset of growth took place in the greenhouse much earlier than outdoors and the phase of increasing growth was much shorter, as was expected. However, the phase of maximum growth was unexpectedly long. This fact suggests that there is great potential for using greenhouse cultivation to change the growth pattern of cultivated plants in order to obtain more complete utilization of the potential growing season.

The PDF includes a summary in Finnish.

  • Koskimäki, E-mail: ak@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
  • Kanninen, E-mail: mk@mm.unknown
  • Kellomäki, E-mail: sk@mm.unknown
article id 4991, category Article
Pertti Harstela, Leo Tervo. (1978). Taimikkopuun korjuumenetelmien vertailua. Silva Fennica vol. 12 no. 2 article id 4991. https://doi.org/10.14214/sf.a14845
English title: Comparison of methods for harvesting in sapling stand.
Original keywords: metsätyö; taimikko; harvennus; koneellistaminen; kustannukset; korjuukustannukset; haketus
English keywords: thinning; mechanization; seedling stand; forest work; harvesting costs
Abstract | View details | Full text in PDF | Author Info

A theoretical nomogram was made for estimating the costs of fully mechanized thinning and the driving speed of the machine. Based on this nomogram and the previous studies three harvesting methods were compared; systematic fully mechanized harvesting, selective fully mechanized harvesting, and manual felling combined with whole-tree chipping.

The third method was cheaper than the fully mechanized methods in a pole-stage stand. The choice of the most advantageous chipping station depended on conditions, but the smaller tree size and possibly the reduced damage on the remaining stand favour chipping on the strip road rather than chipping on the intermediate landing or at the mill.

Mechanized systematic thinning was the cheapest method for harvesting in the sapling stand. The required driving speed were so low that ergonomic factors should not hinder its use. Factors related to the future production of the stand do, however, limit its use. Mechanized selective thinning does not seem to be an economic method for harvesting in a sapling or pole-stage stand.

The PDF includes a summary in English.

  • Harstela, E-mail: ph@mm.unknown (email)
  • Tervo, E-mail: lt@mm.unknown
article id 4983, category Article
Satu Huttunen. (1978). The effects of air pollution on provenances of Scots pine and Norway spruce in northern Finland. Silva Fennica vol. 12 no. 1 article id 4983. https://doi.org/10.14214/sf.a14837
Keywords: Pinus sylvestris; Norway spruce; Scots pine; provenance; northern Finland; mortality; seedlings; air pollution; Picea abes
Abstract | View details | Full text in PDF | Author Info

The success of certain Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) provenances from Northern Finland was studied in a tree damage area occasioned by air pollution in the town of Oulu over the period of 1972-76. The pine strains from more northerly and easterly areas and the spruce strains from the immediate vicinity of the site itself were being observed to thrive best. The results point in a similar direction to those of other comparable experiments, except that the mortality rate amongst the saplings was exceptionally high and the proportion of healthy saplings in good condition was found to be unusually low. Structural properties suggestive of resistance to pollution were observable selectively in certain provenances, these including the xeromorphy of needles or thickness of the epidermis. The chief cause of mortality amongst the saplings was found to be the damage inflicted by pollution during the winter, while that arising in the summer months was relatively slight.

The PDF includes a summary in Finnish.

  • Huttunen, E-mail: sh@mm.unknown (email)
article id 4963, category Article
Tapio Lehtiniemi. (1977). Männyn ja kuusen siementen gammasäteilyherkkyyteen vaikuttavista tekijöistä. Silva Fennica vol. 11 no. 1 article id 4963. https://doi.org/10.14214/sf.a14814
English title: Factors affecting gamma-irradiation sensitivity of Scots pine and Norway spruce.
Original keywords: kuusi; mänty; alkuperä; itäminen; siemenet; säteilytys
English keywords: Pinus sylvestris; Norway spruce; Picea abies; germination; Scots pine; progeny; seeds; radiation
Abstract | View details | Full text in PDF | Author Info

This study, comprising three experiments, aims to determine the effect of the geographical origin of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seeds, and the duration of the time lag between the moisture treatment and subsequent irradiation on the gamma-irradiation sensitivity of seeds.

The studies showed that the greater the irradiation dose seeds were subjected to the slower the rate of germination. In general, small radiation doses (250–1,000 rad) had a stimulating effect and the final germination percentage (36–40 days) increased. However, when the level was further increased, the germination percentage decreased. Air-dry and moistened seeds withstood irradiation better than others. In a study with moistened seeds from different geographical sources, pine and spruce seeds from Northern Finland were less able to withstand irradiation than those originating from the south.

The PDF includes a summary in English.

  • Lehtiniemi, E-mail: tl@mm.unknown (email)
article id 4954, category Article
Carl Johan Westman. (1976). Fertilization of Scots pine seedlings with different nitrogen fertilizer. Silva Fennica vol. 10 no. 4 article id 4954. https://doi.org/10.14214/sf.a14800
Original keywords: mänty; istutus; kasvu; taimet; lannoitus; kuolleisuus; typpilannoitus; ammoniumsulfaatti
English keywords: Pinus sylvestris; Scots pine; planting; growth; mortality; seedlings; fertilizing; nitrogen fertilizers; ammonium sulphate
Abstract | View details | Full text in PDF | Author Info

The paper describes an attempt to determine whether ammonium, nitrate and urea nitrogen are bound in peat used as a filling material in containerized seedling production, what is the effect of the nutrients on certain chemical properties in the peat, and what is the effect of the nitrogen fertilizers on the primary growth of containerized (paper-pot VH 608) Scots pine (Pinus sylvestris L.) seedlings in connection with planting out. The seedlings were fertilized with ammonium sulphate, potassium nitrate and urea.

The results show that none of the fertilizers used were bound in the peat. The nitrogen content in the above ground part of the seedlings increased clearly. Fertilization with ammonium sulphate resulted in the greatest increment and this increase appears to be permanent. The wintering process was somewhat delayed by the fertilization. The seedling mortality rate for all the treatments has been quite appreciable. However, fertilization particularly with ammonium sulphate on the poorer of the two sites studied has had a positive effect on seedling survival. Furthermore, it appears that fertilizer treatments have decreased growth after planting, but in the case of ammonium sulphate this decrease has changed into a clear growth increment.

The PDF includes a summary in English.

  • Westman, E-mail: cw@mm.unknown (email)
article id 4930, category Article
Tapio Lehtiniemi. (1976). Ionisoivan säteilyn vaikutus varastokuivien ja liotettujen metsäpuiden siementen idäntään ja taimien alkukehitykseen. Silva Fennica vol. 10 no. 1 article id 4930. https://doi.org/10.14214/sf.a14772
English title: Effect of ionizing radiation on the germination of storage-dry and soaked forest tree seeds and on the initial development of seedlings.
Original keywords: metsänjalostus; itäminen; siemenet; säteilytys; mutaatiot
English keywords: Pinus sylvestris; Betula pendula; Picea abies; germination; Betula pubescens; Alnus glutinosa; Alnus incana; seeds; forest tree breeding; radiation; mutations
Abstract | View details | Full text in PDF | Author Info

The study was carried out in order to find out the changes taking place in germination of seeds in certain tree species as a function of gamma irradiation, the height growth of the seedlings produced and the types of phenotypic mutants possibly found in the generation that had received radiation. The tree species studied were Pinus sylvestris L., Picea abies (L.) H. Karst., Betula verrucosa (Betula pendula Roth), B. Pubescens Ehrh., Alnus glutinosa (L.) Gaertn. and Alnus incana (L.) Moench.

Soaked seeds that had received a rather small dose of radiation germinated usually better than storage-dry seeds, B. pubescens being an exception. The damages observed in germination, height growth and the relative number of mutants were greater the higher the irradiation doses. The LD50 dose (germination, 28 days) was as follows in the case of the different tree species (storage dry/soaked): P. Sylvestris 1,500-2,000/2500-3,000, P. abies 1,000-1,500/4,000-4,500, B. pendula 9,500-10,000/7,000-7,500, B. pubescens >10,000/7,500-8,000 and A. Glutinosa 10,000/8,500-9,000 rad. Mass production of different mutants of deciduous trees for ornamental purposes, for example, appears to be easy using gamma-irradiation. On the other hand, the possibility of increasing tree growth remains open for further study.

The PDF includes a summary in English.

  • Lehtiniemi, E-mail: tl@mm.unknown (email)
article id 4910, category Article
Erkki Lähde, Katri Pahkala. (1974). Havupuiden siemenen kehitys ja itäminen kirjallisuuden valossa. Silva Fennica vol. 8 no. 4 article id 4910. https://doi.org/10.14214/sf.a14754
English title: Development and germination of the seeds of conifers according to literature.
Original keywords: kylvö; havupuut; itäminen; esi-idätysmenetelmä; kukkiminen; siementen kehitys; pölytys
English keywords: germination; flowering; conifers; pollination; seeds; sowing; seeding; development of seeds; pre-germination method
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to collect information presented in literature concerning the development and germination of the seeds of coniferous trees with special reference to those species which thrive in the conditions prevailing in Finland. Along with the increase in the importance of direct seeding as a silvicultural means in Northern Finland, there is a growing demand for methods by means of which the germination of seeds could be promoted. According to the results obtained from previous studies, such a method can be found, provided that a practically usable and reliable pre-germination method is developed.

The PDF includes a summary in English.

  • Lähde, E-mail: el@mm.unknown (email)
  • Pahkala, E-mail: kp@mm.unknown
article id 4908, category Article
Juhani Päivänen. (1974). Sarkaleveyden ja naveroinnin vaikutus pohjavesipinnan syvyyteen ja männyntaimiston kehitykseen lyhytkortisella nevalla. Silva Fennica vol. 8 no. 4 article id 4908. https://doi.org/10.14214/sf.a14752
English title: The effect of ditch spacing and furrowing on depth of ground water table and on development of a Scots pine plantation on small-sedge bog.
Original keywords: mänty; ojitetut suot; avosuot; pituuskasvu; sarkaleveys; naverointi; kuivatussyvyys; kuivatusteho
English keywords: Pinus sylvestris; drained peatlands; Scots pine; height growth; seedlings; open peatlands; drainage effect; ground water table; ditch spacing; furrowing
Abstract | View details | Full text in PDF | Author Info

The paper describes the results obtained from an investigation into the effect of ditch spacing, ditch depth and furrowing on ground water table and on development of a Scots pine (Pinus sylvestris L.) plantation on open small-sedge bog in Central Finland (60° 50’ N; 24° 20’ E), drained in 1967. The area was planted in 1968 with 2+1 Scots pine transplants, and fertilized with Y fertilizer for peat soils. The seedlings were measured in 1972.

The depth of the ground water table was greater, the narrower the ditch spacing. The water furrows shortened the duration of the high ground water and lowered the ground water table particularly in the case of ineffective drainage. The narrower the ditch spacing within the blocks, the higher were the young trees. On the other hand, the differences in the height of the trees between the ditch spacings were eliminated by the effect of the furrows.

The PDF includes a summary in English.

  • Päivänen, E-mail: jp@mm.unknown (email)
article id 4889, category Article
Tapio Lehtiniemi. (1973). Turvepuristeet ja männyn kylvö. Silva Fennica vol. 7 no. 4 article id 4889. https://doi.org/10.14214/sf.a14727
English title: Use of peat briquettes in seeding of Scots pine.
Original keywords: kylvö; mänty; itäminen; kasvualustat; turve; turvebriketti; vakoruutukylvö
English keywords: Pinus sylvestris; germination; Scots pine; peat; sowing; seeding; band-sowing
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to assess, through field experiments, the possibilities of using peat briquettes in the seeding of Scots pine (Pinus sylvestris L.) in Southern Finland. The briquettes were dug into the soil in the middle of patches of mineral soil. The seeds were covered by a 2-5 mm layer of mineral soil. The seedings were inventoried in the three following autumns.

According to the results, the briquettes were clearly inferior to the control, which was ordinary drill seeding. This was mainly due to the fact that no rain was received after the seeding, and that the third summer from seeding was extremely dry. Abundant germination was observed during the second summer after seeding in both briquette seeding and the control. During more rainy summers the result might have been better.

The PDF includes a summary in English.

  • Lehtiniemi, E-mail: tl@mm.unknown (email)
article id 4877, category Article
Pertti Laatikainen. (1973). Jyrsinturve ja kuorihumus männyn kylvötaimien kasvualustoina muovihuoneessa. Silva Fennica vol. 7 no. 1 article id 4877. https://doi.org/10.14214/sf.a14707
English title: Milled peat and milled bark as substrate for Scots pine seedlings in greenhouses.
Original keywords: mänty; taimitarha; taimituotanto; lannoitus; kasvualustat; kasvihuoneviljely; kuorihumus; turve
English keywords: Pinus sylvestris; nursery; Scots pine; substrate; tree seedlings; greenhouse cultivation; milled peat; milled bark
Abstract | View details | Full text in PDF | Author Info

The purpose of this study was to compare the development of Scots pine (Pinus sylvestris L.) seedlings sown on substrates off milled peat and milled bark. Mille peat, ordinary milled bark, milled inner bark waste, and a mixture of milled peat and milled bark in the ratio of 1:1, were all compared in the plastic greenhouse. In addition, two fertilization applications were used with milled park: ordinary surface fertilization and double surface fertilization. The germination and development were measured twice during the summer.

It is concluded that milled bark seems to be a rather useful substrate for use in plastic greenhouses, as long as its special requirements are taken into consideration. In the first measurement, there were no differences between the treatments, in the second measurements seedlings growing on a mixture of peat and bark were slightly more developed than the others. Growth of the seedlings was slightly better in ordinary milled bark. Double surface fertilization increased disease and mortality compared to ordinary fertilization.

The PDF includes a summary in English.

  • Laatikainen, E-mail: pl@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 4859, category Article
Eljas Pohtila. (1972). Istutuskuoppaan annetun kuparihienofosfaatin vaikutus männyn ja kuusen taimien elossapysymiseen ja pituuskasvuun eräällä kulotetulla ja auratulla uudistusalalla Koillis-Suomessa. Silva Fennica vol. 6 no. 1 article id 4859. https://doi.org/10.14214/sf.a14662
English title: Effect of fine-grounded copper rock phosphate placed in the planting hole on the survival and height growth of Scots pine and Norway spruce in a burnt and furrowed reforestation are in northeast Finland.
Original keywords: kuusi; mänty; metsänviljely; taimet; lannoitus; kuolleisuus; pituuskasvu; fosforilannoitus
English keywords: Pinus sylvestris; Norway spruce; fertilization; Picea abies; Scots pine; height growth; planting; phosphorus; mortality; copper; seedlings
Abstract | View details | Full text in PDF | Author Info

The paper describes the results of a fertilization experiment, in which transplants of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) were fertilized with various doses of fine-ground copper rock phosphate (33% P2O5, 4% Cu) placed direct in the planting hole. The experiment was made in northeast Finland on a clear-cut, burnt-over and furrowed moraine heath. The fertilization increased especially the survival and condition of the Scots pines and increased to some extent also the height growth of the plants. The spruce survived better than the pines.

The PDF includes a summary in English

  • Pohtila, E-mail: ep@mm.unknown (email)
article id 4856, category Article
Pekka Rautiainen. (1971). Ympäristö- ja perintötekijöiden vaikutus männyn ilmiasuun Pohjois-Karjalan piirimetsälautakunnan siemenviljelyksessä Tohmajärvellä. Silva Fennica vol. 5 no. 4 article id 4856. https://doi.org/10.14214/sf.a14658
English title: The effect of environmental and genetical factors on the phenotype of Scots pine in a seed orchard in North Karelia.
Original keywords: mänty; oksikkuus; Suomi; periytyvyys; pituuskasvu; fenotyppi; heritabiliteetti; siemenviljelmä; Tohmajärvi; oksakulma
English keywords: Pinus sylvestris; Scots pine; height growth; heritability; branchiness; fenotyyppi; seed orchard; angle of branching
Abstract | View details | Full text in PDF | Author Info

The study material included 600 Scots pine (Pinus sylvestris L.) grafts from the Tohmajärvi seed orchard in Eastern Finland. Their broad sense heritability for the height growth was 0.92, for the number of branches 0.87 and for the angle of branching 0.84. Grafts from Central Finland had cones more often than the southern ones, the frequencies being 26.3% and 11.2%. It seems that dominance plays a significant role in the genetical variation of this seed orchard and that height growth is probably more rewarding breeding characteristic than quality, the difference being small, however.

The PDF includes a summary in English.

  • Rautiainen, E-mail: pr@mm.unknown (email)
article id 4853, category Article
Olavi Luukkanen, Pentti K. Räsänen, Paavo Yli-Vakkuri. (1971). Neulasten väri myöhemmän kasvun ja lannoitusvaikutuksen ilmaisijana. Silva Fennica vol. 5 no. 4 article id 4853. https://doi.org/10.14214/sf.a14655
English title: The use of needle colour in predicting growth and response to fertilization.
Original keywords: kuusi; mänty; kasvu; taimet; lannoitus; neulaset
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; planting; growth; seedlings; needle clour
Abstract | View details | Full text in PDF | Author Info

About 4,000 seedlings of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) were planted in 1965 both on a clear-cut and sheltered area in Central Finland. In the autumn of 1966 needle colour was determined by using Muncell Color Charts which allowed a quantitative measurement of three colour dimensions (hue, value, and chroma). Terminal shoot growth was recorded for two years after colour measurements. In both species, fertilization (NPK in the spring of the year of colour measurement) as well as other site factors caused differences in all three dimensions of needle colour. A regression of shoot growth on needle colour was found in both species. In most cases colour value (darkness) and, in spruce, also chroma, predicted the subsequent growth almost as well as did these two-colour variables together.

The PDF includes a summary in English.

  • Luukkanen, E-mail: ol@mm.unknown (email)
  • Räsänen, E-mail: pr@mm.unknown
  • Yli-Vakkuri, E-mail: py@mm.unknown
article id 4849, category Article
Pentti K. Räsänen, Tapani Hänninen. (1971). Eräiden talvivarastointimenetelmien vaikutuksesta männyn taimiin. Silva Fennica vol. 5 no. 3 article id 4849. https://doi.org/10.14214/sf.a14651
English title: The effect of some over-winter storage methods on different Scots pine nursery stock.
Original keywords: mänty; taimet; varastointi; talvivarastointi; kuolleisuus; kylmävarastointi
English keywords: Pinus sylvestris; Scots pine; planting; mortality; seedlings; cold storage; winter storage
Abstract | View details | Full text in PDF | Author Info

Seedlings of three different Scots pine (Pinus sylvestris L.) nursery stock, 1+0 ,1+1, and 2+0, were kept over the winter, after they had been packed in polythene bags, in three different ways: 1) In a refrigerated storage room, 2) in a wooden crate in the ground, 3) submerged in a lake. The seedling to which they were to be compared with were left over the winter in a nursery bed. The 1,800 seedlings were planted out in the spring 1966 in 15 random blocks. Their development was scrutinized during the three subsequent falls.

The seedlings which had been stored in the lake all died. The seedlings which had been stored along the 1st and 2nd method, managed almost as well as the ones which had been kept over the winter in the nursery bed, except for those of 1+0 stock.

The PDF includes a summary in English.

  • Räsänen, E-mail: pr@mm.unknown (email)
  • Hänninen, E-mail: th@mm.unknown
article id 4847, category Article
Pentti K. Räsänen, Matti Hiltunen. (1971). Männyn erilaisten taimierien istutuskelpoisuudesta. Silva Fennica vol. 5 no. 3 article id 4847. https://doi.org/10.14214/sf.a14649
English title: The effect of differences in Scots pine nursery stock on the field survival and growth.
Original keywords: mänty; metsänviljely; istutus; kasvu; taimet; varastointi; kastelu; kuolelisuus
English keywords: Pinus sylvestris; Scots pine; planting; growth; mortality; storage; seedlings; watering
Abstract | View details | Full text in PDF | Author Info

Scots pine (Pinus sylvestris L.) seedlings were stored for five days in an ordinary wood shed. One half of the seedlings were planted out directly, and another half after soaking the roots of the seedlings for 3–6 hours in water to compensate the possible water deficit developed. According to the results of the experiment, the effect of watering was extremely small. The difference observed, which was in favour of the trees that had been watered during storage, was discernible only in the needle length and in the number of lateral buds; in mortality or in the growth of the seedlings no difference could be observed.

The PDF includes a summary in English.

  • Räsänen, E-mail: pr@mm.unknown (email)
  • Hiltunen, E-mail: mh@mm.unknown
article id 4838, category Article
Kustaa Seppälä. (1971). Metsityslannoituksessa käytetyn lannoitemäärän ja levitystavan merkitys istutustaimiston alkukehitykselle ojitetuilla avosoilla. Silva Fennica vol. 5 no. 2 article id 4838. https://doi.org/10.14214/sf.a14640
English title: The quantity of fertilizer and application methods used in afforestation of open bogs.
Original keywords: mänty; istutus; metsitys; taimet; turvemaat; lannoitus; ojitetut suot; avosuot; kuolleisuus; pituuskasvu
English keywords: Pinus sylvestris; fertilization; afforestation; drained peatlands; Scots pine; height growth; mortality; seedlings
Abstract | View details | Full text in PDF | Author Info

The paper describes the results obtained from an experiment of fertilization of drained treeless peatlands in connection of planting in three sites in Central Finland. Scots pine (Pinus sylvestris L.) seedlings 2+0 was used. The fertilizer (Y-fertilizer for peat soils, 14% N, 18% P2O5, 10% K2O) was applied in rates of 0, 20, 40 and 80 g/transplant. The fertilizer was strewn either around the plant within a circular patch of 20 cm in diameter, in a ring with a radius of 10 cm and in a ring with a radius of 20 cm. The seedlings were measured two and five years after planting.

The greater the quantity of fertilizer applied and the closer it was applied to the plant the higher was the mortality of transplants. Fertilization increased the mortality during the first two growing seasons after application. Later, however, the mortality decreased to a similar level irrespective the way the fertilizer was applied. In the beginning of the second growing season the fertilized plants showed considerably better height growth than the control plants. The smallest quantity of fertilizer applied produced almost full increase in growth. The pattern of application of the fertilizer had little effect on the growth.

It was concluded that a use of small amounts of fertilizer can be recommended in connection with planting and that it should not be applied very near the seedlings.

The PDF includes a summary in English.

  • Seppälä, E-mail: ks@mm.unknown (email)
article id 4834, category Article
Bo Långström. (1971). Weight loss, water content and mortality of cold stored Scots pine seedlings. Silva Fennica vol. 5 no. 1 article id 4834. https://doi.org/10.14214/sf.a14623
Keywords: Pinus sylvestris; Scots pine; mortality; seedlings; cold storage; weight loss; water content; storage conditions
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to investigate how the weight loss and water content of cold stored plants depend on the storage conditions, and if there is a clear connection between these factors and the field survival of the planting stock. The experiments were carried out in a climate chamber at about +2°C and at three moisture levels (about 70, 85, and 95%) from November 1968 to May 1969. Three-year-old seedlings of Scots pine (Pinus sylvestris L.) average length 127 mm, diameter 3.5 mm and the top/root-ratio of fresh weight 1.93, were stored in open and sealed plastic bags. In addition, a transpiration retardant (Silvaplast) was used. The plastic bags (10 plants each) were weighted every 4. week. The remaining 270 seedlings were planted out and inspected after one growing season.

Although the experiment was made in a small scale, the results showed clearly that plant mortality, varying between 3 and 97%, was due to the storage conditions. The weight loss ranged between 2 and 50%, and the correlation between the weight loss and the mortality in the field was high. The water content of the seedlings was about 61%. The correlation between water content and survival was very high. Thus, the determination of weight loss or water content could be a useful method in observing the changes of water balance of the seedling stock during winter-storage. Further investigations are needed to show the tolerable rate of drying out for different sorts of plants. The Silvaplast-treatment had no visible effect either on the drying out or on the field survival.

The PDF includes a summary in English.

  • Långström, E-mail: bl@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 4817, category Article
Leo Heikurainen, Jukka Ouni. (1970). Turvemaiden taimistojen pituuskasvusta. Silva Fennica vol. 4 no. 2 article id 4817. https://doi.org/10.14214/sf.a14606
English title: Height growth of seedling stands growing on peatland.
Original keywords: kuusi; mänty; turvemaat; lannoitus; ojitetut suot; taimikot; pituuskasvu; ylispuusto
English keywords: Pinus sylvestris; Norway spruce; fertilization; Picea abies; drained peatlands; Scots pine; height growth; peatlands; seedling stands; hold-overs
Abstract | View details | Full text in PDF | Author Info

This paper presents the results of a contest performed on behalf of the Finnish bank Kansallis-Osake-Pankki and the Central Forestry Board Tapio on growing trees on peatlands. Over 5,000 sample plots were established on drained peatlands in various parts of Finland. The aim was to achieve a best possible growth of seedling stands on peatland. The factors influencing the growth of 85 best Scots pine (Pinus sylvestris L.) and 60 best Norway spruce (Picea abies (L.) H.Karst.) sample plots were studied.

The height growth of the seedling stands decreased towards the north. Fertilization seemed not to decrease the regional differences; rather on the contrary. On the other hand, fertilization increased height growth, but evidently so that the increase obtained was greater in the southern than in the northern parts of the country. Light fertilization (50 kg/ha of K2O and 60 kg/ha of O2P5) caused a clear increase in height growth while heavy fertilization (100 g/ha of K2O and 120 kg/ha of O2P5), had same effect but to much greater extent than the former. Spruce seedling stands in particular benefitted of the heavy fertilization.

Fertilization did not eliminate the original differences in the quality of the sites in question, but these could still be seen in the height growth after fertilization. The effect of drain spacing on the height growth was not very clear. In dense seedling stands (800 seedlings/ha) the height growth of the dominant seedlings was greater than that obtained in stands of lower density. Hold-overs caused a decrease in the growth of the seedling stands.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@mm.unknown (email)
  • Ouni, E-mail: jo@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 4813, category Article
Bo Långström. (1970). Pakkaustapojen vaikutuksesta talvivarastoitujen männyn taimien istutukseen. Silva Fennica vol. 4 no. 1 article id 4813. https://doi.org/10.14214/sf.a14602
English title: The effect of packing methods on the field survival and growth of winter-stored plants of Scots pine.
Original keywords: mänty; metsänviljely; istutus; kasvu; taimet; kylmävarasto; talvivarastointi; kuolleisuus; tukkimiehentäi; torjunta-aine
English keywords: Pinus sylvestris; nursery; Scots pine; planting; seedlings; cold storage; winter storage; Hylobious abietis; large pine weevil; insecticide; field survival; packing methods
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to investigate the effect of four packing methods on the field survival and growth of seedlings and transplants of Scots pine (Pinus sylvestris L.) stored over the winter in a cold-storage cellar. The following sorts of plants were used: one-year-old seedlings (1+0) grown in a plastic greenhouse, two-year-old (2+0) open grown seedlings and three-year-old open grown transplants. These plants were stored in open wooden boxes, in sealed plastic bags, in boxes with wet peat on the bottom and in plastic-laminated paper bags.

The control plants were of the same types and were kept in a nursery over the winter. The storage was carried out in a mantle-chilled cold-storage from October 1966 to May 1967. The temperature in the cold-storage was kept around -2 °C and the relative humidity of the air over 90%. The water content of a randomly selected sample plants showed no increase in water deficit after the storing. Part of the seedlings were transplanted in the nursery and the rest were planted in a clear-cut area. A number of the latter plants were treated with an insecticide (1% Intaktol, which contains DDT, Lindane and dieldrin) before planting. All the experiments were examined after one growing season and the planting experiments the next fall.

The transplants (2+1) in the nursery, and in the forest had survived and grown better than the seedlings. In the nursery the 1+0 seedlings survived and grew better than the 2+0 seedlings. There was no difference in mortality between the seedlings. After the first growing season occasional significant differences between the packing methods were observed, but they disappeared during the second growing season. Thus, all packing methods proved to be as successful as the control method without winter storage.

Transplants were more often attacked by the large pine weevil (Hylobius abietis L.) than the smaller seedlings. The damage, however, was considerably greater on the seedlings because of their lower resistance. No significant differences in the Hylobius-attack between the packing methods could be observed. The Intaktol-treated plants were as often attacked as the untreated ones, but the damage was slighter on the treated ones.

The PDF includes a summary in English.

  • Långström, E-mail: bl@mm.unknown (email)
article id 4812, category Article
Pentti K. Räsänen, Aarno Koukkula, Paavo Yli-Vakkuri. (1970). Pakkauksen, varastoimisen ja valeistutuksen vaikutus männyn taimien istutuskelpoisuuteen. Silva Fennica vol. 4 no. 1 article id 4812. https://doi.org/10.14214/sf.a14601
English title: The effect of packing, storing and heeling-in on the field survival and growth of Scots pine seedlings.
Original keywords: mänty; metsänviljely; istutus; metsäpuun taimet; taimet; varastointi; kuolleisuus; kastelu; tukkimiehentäi
English keywords: Pinus sylvestris; Scots pine; planting; mortality; storage; Hylobius abietis; seedlings; large pine weevil; insecticide; field survival
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to establish, by means of planting experiments, the influence of different packing, heeling-in and watering as well as the length of the storage period on the development of Scots pine (Pinus sylvestris L.) seedlings, in all 2,090 seedlings, that had been lifted from the nursery bed in spring. The plants were packed in bundles and into plastic sacks in 1965 (6 storage methods) and in 1966 (3 storage methods). Control seedlings were planted without storing at the time when storage of the test material begun. The plantations were followed 3–4 years.

Storage for two weeks in the different ways and planting without storage gave similar results when seedling survival was compared. Storage in plastic sack proved to be as good as storage in bundles in a cellar, and healing-in in moist soil or in a drain were both usable methods. Watering the seedlings did not improve the results, which indicates that the storage caused no serious lack of water.

After four growing seasons an average of 19,6% of the seedlings of the 1965 experiment died, the bulk of them by the end of the first growing season. Despite control treatment, Hylobious abietis caused serious damages. In the plantations of the year 1966 mortality of the seedlings was under 5% by the end of third growing season. During the first two growing seasons after planting differences in growth of the seedlings stored in different ways could be observed in the plantations of the year 1965, but the differences levelled out later. In the plantations established in 1966 no differences in growth occurred.

The PDF includes a summary in English.

  • Räsänen, E-mail: pr@mm.unknown (email)
  • Koukkula, E-mail: ak@mm.unknown
  • Yli-Vakkuri, E-mail: py@mm.unknown
article id 4810, category Article
Pentti Solin. (1970). Kuusen käpyjen säilyttäminen jäähdyttämössä ja sen vaikutus niistä saatavan siemenen itävyyteen. Silva Fennica vol. 4 no. 1 article id 4810. https://doi.org/10.14214/sf.a14598
English title: Cold storage of Norway spruce cones and its effect on seed viability.
Original keywords: kuusi; varastointi; siemenet; itävyys; kävyt; kylmävarasto
English keywords: Norway spruce; Picea abies; germination; storage; viability; seeds; cones; cold storage
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to establish how the cold storage of cones of Norway spruce (Picea abies (L.) H. Karst.) affects the viability of the seeds and the percentage ratio in 7 days. A parallel study was made of the longevity of seed in barn-stored cones subject to weather fluctuations and the longevity of seed extracted immediately and stored in the conventional way in an air-tight container. The cones were collected near Kuopio in Central Finland and near Tampere.

The viability and germination rate of the control sample was constant throughout the storage period. This storage method proved the best. The viability of seeds kept in cones declined in cold storage after 3 ½ months. The cones collected in Tampere were damaged by Laspeyresia strobilella, which affected the viability of the seeds.

The viability of seeds stored in cones in a barn had not weakened by the end of May, however, they deteriorated during the summer, as did the seeds stored in cones in the cold storage. Viability of the seeds was still 94% in October. The germination rate was constant in each lot up to the end of May, after which it decreased to 81.7–86.1% in October.

The results show that healthy spruce cones can be stored in paper sacks in a single layer in cold storage and in an ordinary barn for several months without it affecting the viability of the seeds.

The PDF includes a summary in English.

  • Solin, E-mail: ps@mm.unknown (email)
article id 4808, category Article
Erkki Lähde, Antti Oksanen. (1969). Morfologiset, gravimetriset ja fotometriset tunnukset männyn taimien juuristojen kuvaajina. Silva Fennica vol. 3 no. 4 article id 4808. https://doi.org/10.14214/sf.a14596
English title: Morphological, gravimetric, and photometric characteristics in describing of the root systems of pine transplants.
Original keywords: mänty; Pinus sylvestris; juuristo; taimet; mittausmenetelmät; juurten pinta-ala; morfologia
English keywords: Scots pine; seedlings; root system; surface area of the root system; morphology
Abstract | View details | Full text in PDF | Author Info

This project studied the value of various shoot and root-system characteristics as indicators of plantability of transplants. Correlation and regression analysis was used to compare these characteristics. The study material consisted of two-year Scots pine (Pinus sylvestris L.) transplants that had grown in a plastic greenhouse for the first year and then been transplanted in the open. The seedlings had been transplanted in the field without treatment or with the roots cut to a length of 8 cm. A part was transplanted without treatment into plastic pails. A gravimetric and photometric method was used to obtain a description of the surface area of the root systems.

The results show that the photometric value gives a good picture of the surface area of the root system. The greatest advantage offered by the method is the simplicity and rapidity of measurement. The gravimetric, and especially the titrimetric, measurement takes much more time per plant. Photometric measurement affects plantability little, and measured and planted transplants can be followed up in the field. In gravimetric measurements, it was found that fresh and dry weight of the plants were closely correlated.

Mycorrhizal frequency in the root systems gave a good picture of the surface area of the root system. The number of living roots-tips was also rather closely correlated with the surface area of the root system. The other morphological characteristics failed to serve as a satisfactory index for the surface area of root systems. The one closest correlated was the annual leader growth. The second best was stem diameter; the height of the plant, on the contrary, was rather poorly correlated with the other characteristics.

The PDF includes a summary in English.

  • Lähde, E-mail: el@mm.unknown (email)
  • Oksanen, E-mail: ao@mm.unknown
article id 4807, category Article
J. G. Iyer, G. Chesters, S. A. Wilde. (1969). Recovery of growth potential of nursery stock produced on biocide-treated soils. Silva Fennica vol. 3 no. 4 article id 4807. https://doi.org/10.14214/sf.a14595
Keywords: recovery; tree seedlings; nurseries; tree nurseries; biocides; growth disturbances; pesticide; abnormal growth
Abstract | View details | Full text in PDF | Author Info

Certain biocides used in production of tree nursery stock exterminate undesirable organisms but cause an abnormal growth stimulation of plants. The reforestation material has decreased survival potential because of high degree of succulence, top:root and height:diameter ratios, and low specific gravity and root surface area. Some fumigants impede mycorrhizae development and arrest phosphorus uptake. Recovery of growth potential was achieved by aluminium sulphate and/or fermented compost inoculated with mycorrhiza-forming fungi.

The PDF includes a summary in Finnish.

  • Iyer, E-mail: ji@mm.unknown (email)
  • Chesters, E-mail: gc@mm.unknown
  • Wilde, E-mail: sw@mm.unknown
article id 4803, category Article
Kari Löyttyniemi. (1969). Männyn ja kuusen siemenien esikäsittelyn vaikutuksesta itämiseen ja taimien alkukehitykseen kasvihuoneoloissa. Silva Fennica vol. 3 no. 3 article id 4803. https://doi.org/10.14214/sf.a14591
English title: The effect of treatment of Scots pine and Norway spruce seeds on their germination and the early development of the seedlings.
Original keywords: kuusi; mänty; taimettuminen; itäminen; esikäsittely; siemenet; taimikuolleisuus
English keywords: Pinus sylvestris; Norway spruce; Picea abies; germination; Scots pine; seedlings; seeds; treatment of seeds; mortality of seedlings
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to establish the need of treatment of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seeds to be sown in greenhouse. 3 x 100 seeds of each treatment (soaking in water, treatment with Pb3O4, treatment with tiram-containing coating substance) were sown in a glasshouse on a fertilized garden peat, and covered with peat layer of 6 mm thickness. The development of seedlings was followed for 100 days before the final measurement.

Soaking the seeds with water made germination somewhat faster. In spruce the germination percentage increased, but the opposite was observed in pine. No difference could be observed between the results from soaking with acid water from peat soil and lake water. Drying the soaked seeds for a week before sowing had no harmful influence on the germination or the early development of the seedlings. Treatment with Pb3O4 did not affect the germination speed or the seedling percentage of pine or spruce, but increased the germination percentage of spruce. Coating decreased germination and seedling percentages in pine. However, the differences between the treatments were so small that their practical significance is negligible.

Germination of both the species initiated on an average in 8 days, and 16 days after sowing 80% of the seeds had germinated. Seedling mortality was about 10% of the total number of seedlings, the most common reason being damping-off.

The PDF includes a summary in English.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 4802, category Article
Kari Löyttyniemi. (1969). Äkämäpunkkilaji (Nalepella haarlovi var. piceae-abietis Löyttyniemi, Acarina, Eriophyidae) kuusen taimien tuholaisena taimitarhoissa. Silva Fennica vol. 3 no. 3 article id 4802. https://doi.org/10.14214/sf.a14590
English title: An Eriophyidae species damaging Norway spruce seedlings in nurseries in Finland.
Original keywords: kuusi; hyönteistuhot; taimitarha; taimikasvatus; neulaspunkki; kuusen taimet; punkit
English keywords: Norway spruce; Picea abies; needles; seedling damages; nurseries; Acarina; Eriophyidae; Nalepella Haarlovi var. picea-abietis; Nalepella Haarlovi; mites
Abstract | View details | Full text in PDF | Author Info

In Finland the mite Nalepella is found in Norway spruce (Picea abies (L.) H. Karst.) in forests practically in every tree, and even in the nurseries. The paper reports on the occurrence of Nalepella Haarlovi var. picea-abietis Löyttyniemi in Finland in tree nurseries in Finland. The study is based on a large material, collected in connection with an investigation into spruce spider mites.

Nalepella lives vagrantly on the needles. Due to the sucking of the mites, the needles turn yellow, become dry an die. Single patches from sucking cannot be seen by the naked eye. They occur on all sides of the needles. The worst damage to spruce seedlings in nurseries is caused to the needles located in the top of the seedling. Sometimes the terminal bud dryes and the whole terminal shoot can die. However, the whole seedlings seldom die in consequence of the Nalepella mite alone. Subsequent damage to the injured needles is often caused by fungus Cladosporium herbarum.

The study shows that the mite causes economically significant damages only in the nurseries. In forests no such damages were observed in seedlings or in older trees. In 1965–68, significant damages occurred in 16 nurseries in Finland. About 600,000 four-year-old seedlings were destroyed in 1967. The damages were economically important only in the 4-year-old seedlings.

According to the study, seedlings damaged by Nalepella can be used for planting as they recover rather well after planting in the forest. Moreover, the damages end after planting, and density of the mite population decreases during the first summer.

The mite overwinters as egg on needles. The eggs hatch in Southern Finland in the end of April and in the beginning of May.

The PDF includes a summary in English.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 4778, category Article
Kari Löyttyniemi. (1968). Teeri (Lyrurus tetrix L.) männyn taimien tuholaisena taimitarhassa. Silva Fennica vol. 2 no. 4 article id 4778. https://doi.org/10.14214/sf.a14563
English title: Feeding of terminal shoots of Scots pine seedlings by the black grouse (Lyrurus tetrix) in nursery.
Original keywords: mänty; taimitarha; taimituhot; versot; teeri
English keywords: Pinus sylvestris; nursery; Scots pine; forest nursery; seedling damages; feeding behaviour; black grouse; Lyrurus tetrix; terminal buds
Abstract | View details | Full text in PDF | Author Info

In early spring 1968 it was noticed that the black grouses (Lyrurus tetris L.) was eating terminal shoots of Scots pine (Pinus sylvestris L.) seedlings in a tree nursery in Luumäki, Southern Finland. The terminal shoots were picked 1–4 cm from the top of the seedlings. In total some thousands of two-year-old seedlings were damaged. The depth of the snow was 10–15 cm deep and only the tops of the seedlings could be seen above the surface of the snow.

The PDF includes a summary in English.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
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 4766, category Article
Olli Makkonen. (1968). Roomalaisten taimitarhat. Silva Fennica vol. 2 no. 2 article id 4766. https://doi.org/10.14214/sf.a14551
English title: The nurseries of the ancient romans.
Original keywords: historia; taimikasvatus; taimitarhat; puun taimet; taimistot; roomalaiset; Rooman valtakunta
English keywords: history; tree seedlings; nurseries; tree nurseries; romans; Roman empire
Abstract | View details | Full text in PDF | Author Info

The paper outlines the information about forest tree nurseries in the Roman Empire, found in ancient writings. According to the author, it cannot be stated that actual forest cultivation was practiced in the times of the Roman Empire, even if tree seedlings were used for a variety of purposes, such as embellishment of cities, parks and gardens, and raising supporting trees in forest vineyards. Nurseries were usually established on farms to fill the owner’s needs. For instance, Gato, Varro, Virgil, Pliny and Colulmella have given instructions about establishment and management of nurseries, and methods to sowing seeds of different tree species. Except for seeds, both root- and branch-cuttings were used in cultivation of trees. Also, grafting was known.

The PDF includes a summary in English.

  • Makkonen, E-mail: om@mm.unknown (email)
article id 4753, category Article
Helge Johnsson. (1967). Different ways of genetic improvement of forest trees in Scandinavia. Silva Fennica vol. 1 no. 3 article id 4753. https://doi.org/10.14214/sf.a14537
Keywords: selection; provenance; tree breeding; breeding; seed orchads; hybridization
Abstract | View details | Full text in PDF | Author Info

Transfer of southern provenances of trees to the north leads to an increased growth until the limit of hardiness is exceeded, which may be utilized in practical forestry. Selection from certain local provenances are important both for the immediate supply of seed and on a somewhat longer view. A certain degree of improvement can be achieved by avoiding minus regions and concentrating seed collection on better areas. Also, seeds can be collected from the best stands only, and by accepting only seed from the best trees of such stands. The selection can be strengthened considerably by production of seed orchards. The seed production is based on a small number of trees of particular superiority that are reproduced vegetatively. The clones are planted in an orchard, which pollinate each other.

Hybridization of two different provenances might result in an increased capacity of production. Such hybridized seed can be produced in orchards established, for instance, as a combination of selection and hybridization orchards. As regards the major Scandinavian tree species there are only small prospects of advancement through species hybridization. The method available at present for efficient racial improvement of our forest trees is individual selection in connection with seed production in orchards. In special cases, however, other methods such as transfer of provenances, provenance hybridization, species hybridization, and polyploidization will result in considerable progress.

The PDF includes a summary in English.

  • Johnsson, E-mail: hj@mm.unknown (email)
article id 4752, category Article
T. T. Kozlowski, S. Sasaki, J. H. Torrie. (1967). Effects of temperature on phytotoxicity of monuron, picloram, CDEC, EPTC, CDAA, and sesone to young pine seedlings. Silva Fennica vol. 1 no. 3 article id 4752. https://doi.org/10.14214/sf.a14536
Keywords: herbicides; toxicity; seedlings; Pinus resinosa; phytotoxicity
Abstract | View details | Full text in PDF | Author Info

The apparent toxicity of soil-incorporated monuron, picloram, CDEC, EPTC, CDAA, and sesone to young Pinus resinosa Ait. seedlings was studied over a temperature range of 10–30 °C in growth chambers. The herbicides were first applied to the surface of autoclaved soil at 1 1b/A and later mixed into the soil. Thereafter pine seeds were planted and subsequent seedling development was studied. The effect of CDEC, EPTC, CDAA, and sesone were also studied at dosages of 2 and 3 1b/A (soil surface basis).

Under the conditions of this study, picloram and monuron were persistent in the soil and toxic to pine seedlings, whereas CDEC, EPTC, CDAA, and sesone appeared to be non-toxic. However, the apparent lack of phytotoxicity of the latter group apparently was caused largely by lack of activation of sesone by autoclaving soil and large losses from the soil of CDEC, EPTC, and CDAA even before seeds were planted.

High toxicity of picloram and monuron was showed by reductions in seedling survival, total dry weight increment of plants, and dry weight increment of surviving seedlings. Various temperature regimes greatly affected growth of herbicide treated plants and controls. In control plants both high and low temperatures adversely affected seedling survival and dry weight more than shoot growth. Temperature extremes generally inhibited root growth more than shoot growth. The high temperatures, 25 and 30 °C, markedly enhanced phytotoxicity of picloram and muron.

The PDF includes a summary in Finnish.

  • Kozlowski, E-mail: tk@mm.unknown (email)
  • Sasaki, E-mail: ss@mm.unknown
  • Torrie, E-mail: jt@mm.unknown
article id 4744, category Article
Pekka Tiililä. (1967). Tutkimuksia eräiden ulkomaisten puulajien siemensadon laadusta Suomessa. Silva Fennica vol. 1 no. 2 article id 4744. https://doi.org/10.14214/sf.a14454
English title: Studies on the quality of seed yields in some foreign tree species in Finland.
Original keywords: siementuotanto; ulkomaiset puulajit; siementen laatu; siemensato; tuleentuminen
English keywords: exotic tree species; seed production; seed quality; foreign tree species; ripening
Abstract | View details | Full text in PDF | Author Info

The aim of this present study was to elucidate the quality of seed of foreign tree species grown in Finland, and the factors which have affected the quality of the seed yields. Due to the smallness of the material, however, no far-fetching conclusions can be drawn. The bulk of the seeds were collected in the fall of 1964. The samples of seeds were X-rayed and their classification to empty seeds and full seeds of four quality classes was done on the basis of the anatomical structures. The species studied (a total of 34 species) belonged to the following genera: Abies, Chamaecyparis, Larix, Picea, Pinus, Pseudotsuga, Thuja and Tsuga.

The percentage of empty seeds was throughout quite high. The reasons for the generation of empty seeds probably originate from the special nature of the stands from which the seeds were collected. As a rule, the stands were young and small in area, which may have caused weak pollination and self-pollination leading to embryo mortality. Also, insect damages were observed.

Seeds with albumen still discernible, although the embryo had died, occurred to some extent. In some Larix species, even the bulk of the seeds recorded as full belonged in this group.

The ripening of seeds with embryos was quite successful in spite of the fact that the temperature sum of the year of ripening was slightly below the average in Finland. For instance, all Abies species ripened almost completely.

According to the results, it can be expected that the tree species examined in this study are able to produce rich yields of good-quality seed in Finland, provided that the ovules are well pollinated and self-pollination does not take place to a large extent.

The PDF includes a summary in English.

  • Tiililä, E-mail: pt@mm.unknown (email)
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 4727, category Article
Erkki Pulliainen, Kalervo Salonen. (1965). Orava männyn siemen- ja silmutuholaisena. Silva Fennica no. 117 article id 4727. https://doi.org/10.14214/sf.a14285
English title: Damage caused by squirrel (Sciurus vulgaris) to pine-buds.
Original keywords: mänty; taimituhot; kasvutappiot; orava; silmut
English keywords: Pinus sylvestris; Scots pine; seedling damages; squirrels; Sciurus vulgaris; buds
Abstract | View details | Full text in PDF | Author Info

When the seed harvest of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) are low, pine and spruce buds are among the secondary food items of squirrel (Sciurus vulgaris L.) in Finland. In this study, conducted in Nokia in Southern Finland in 1962-1963, eating of pine buds by squirrel is described. The eaten buds in 15-years old Scots pine seedlings were recorded in two seedling stands.

According to the results, the squirrels selected the largest buds of the best seedlings in the studied stands. In over 50% of the cases the squirrels chose only the buds of the leading shoot, especially the terminal bud. In half of the trees, a side bud of the leading shoot continued the growth, which causes form defects in the trees. In 35% of the damaged trees, a lateral branch continued the growth. Well-growing seedling stands may be especially susceptible for damages caused by, for instance, squirrels.

The PDF includes a summary in Finnish.

  • Pulliainen, E-mail: ep@mm.unknown (email)
  • Salonen, E-mail: ks@mm.unknown
article id 4703, category Article
E. A. Jamalainen. (1961). Havupuiden taimistojen talvituhosienivauriot ja niiden kemiallinen torjunta. Silva Fennica no. 108 article id 4703. https://doi.org/10.14214/sf.a9138
English title: Damage by low-temperature parasitic fungi on coniferous nurseries and its chemical control.
Original keywords: kuusi; mänty; taimet; taimituhot; torjunta-aineet; havupuut; taimitarhat; sienitaudit; talvituhosienet
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; fungicides; seedlings; coniferous seedlings; seedling damages; pathogens; nurseries
Abstract | View details | Full text in PDF | Author Info

Since 1954 studies have been carried out by the Department of Plant Pathology of Agricultural Research Centre on occurrence of low-temperature parasitic fungi in nurseries in Finland. This paper reports analysis of the damage caused by the fungus to Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seedlings.

In Southern and southwestern Finland, scarcely any damage caused by low-temperature parasitic fungi to coniferous seedlings was found. On the other hand, in Central, Eastern and Northern Finland, considerable injuries were present in the seedlings. The extent of damage varies between different localities and in a same location from year to year. The extent of damage is mostly dependent on snow cover which is heaviest in Central and Northern Finland. Damages are largest in wooded areas and in places where snow accumulates abundantly and remains until late in the spring.

The principal cause of winter damage to spruce seedlings is Hepotricia nigra (Hartig) which causes black snow mould. Depending on the amount of infestation, the damage can be limited to scattered groups or consist of large areas of dead seedlings. The fungus is unable to infect the plants during warm months of the growing season. The most damaging parasitic fungus in Scots pine is Phacidium infestans (Karst.) causing snow blight. The infestation varies from reddish-brown patches of infected seedlings to large areas of infected plants. Also, Botrytis cinerea has been determined from one- and two-year plants of pine and spruce.

In trials of chemical control by PCNB (pentachloronitrobenzene) gave nearly complete control of low-temperature parasitic fungi in one-year spruce seedlings. In addition, a compound of zineb (Dithane Z-78) gave similar results. Chemical control of the fungi is now common in the nurseries.

The PDF includes a summary in English.

  • Jamalainen, E-mail: ej@mm.unknown (email)
article id 4693, category Article
Martti Nenonen, Juhani Jukola. (1960). Tukkimiehen täin (Hylobius abietis L.) tuhoista mäntytaimistoissa ja niiden torjunnasta DDT :n avulla. Silva Fennica no. 104 article id 4693. https://doi.org/10.14214/sf.a9132
English title: Pine weevil (Hylobius abietis L.) injuries and their control by DDT in Scots pine seedling stands.
Keywords: Pinus sylvestris; soil preparation; Scots pine; planting; Hylobius abietis; insecticides; seedling damages; insect damages; DDT
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to find out more about pine weevil (Hylobious abietis L.) injuries in Scots pine (Pinus sylvestris L.) seedling stands and their control by means of DDT. For this purpose, inventories were made of seedling stands established earlier. Control experiments were made on burnt areas by planting seedlings dipped in a DDT emulsion.

The results of the inventories show that injuries caused by pine weevils can, in certain circumstances, especially in seedling stands established by planting, cause the complete failure in artificial regeneration. The extent and quality of the injuries vary greatly according to planting method, treatment of the cutting area, age of the seedling stand, environmental factors, and weather conditions. The most extensive injuries occur in regeneration areas of old Norway spruce stands burnt after clear cutting and planted with Scots pine seedlings. Injuries are greater in seedling stands established by planting, especially after broadcast burning, than in seedling stands originating either from artificial or natural seeding. The quality of the patch for sowing or planting has a considerable effect on the quantity and character of the injuries: in a patch from which organic matter has been removed, injuries do not appear or they are slighter. Seedlings can be protected effectively and economically by dipping their tops up to the root collar, in a DDT emulsion before planting.

The PDF includes a summary in English.

  • Nenonen, E-mail: mn@mm.unknown (email)
  • Jukola, E-mail: jj@mm.unknown
article id 4648, category Article
Paavo Yli-Vakkuri. (1955). Männyn kylvötaimistojen hirvivahingoista Pohjanmaalla. Silva Fennica no. 88 article id 4648. https://doi.org/10.14214/sf.a9111
English title: Elk damage in seedling stands of Scots pine in Ostrobothnia.
Original keywords: mänty; Pinus sylvestris; taimituhot; hirvi; hirvituhot; Alces alces; Pohjanmaa; kylvötaimikot
English keywords: Scots pine; moose; seedling stands; seeding; elk; seedling damages; elk damages
Abstract | View details | Full text in PDF | Author Info

The article reviews the occurrence of damage causes by elk (Alces alces L.) in young Scots pine (Pinus sylvestris L.) stands established by direct seeding in the Ostrobothia region in Finland. The data was collected by random sampling, and consists of 110 sample plots in pine stands, established in 1930-1944.

Signs of elk damages could be observed in 20% of the stands. In more than half of the damaged stands pine seedlings were damaged by elk, on the rest of the stands the damage was targeted to hardwood saplings only. With the present density of elk population, the damage has an insignificant bearing upon the development of pine seedling stands in Ostrobothnia. The weaknesses of silvicultural state of the stands have been caused by other factors than elk.

Silviculturally weak stands were more liable to elk damage than strong ones. The occurrence of elk damage was more usual in stands with hardwood mixture than in pure pine stands. Especially goat willow, mountain ash and aspen, but also to some decree birch, seem to attract elk. Those factors that promote hardwood growth: fertility of the site, swampiness and the presence of seeding hardwoods in the area, increase the stand’s liability to elk damage.

The article includes an abstract in English and a summary in Swedish.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
article id 4647, category Article
Pekka Sainio. (1955). Hirven talvisesta ravinnosta. Silva Fennica no. 88 article id 4647. https://doi.org/10.14214/sf.a9109
English title: Winter nutrition of elk.
Original keywords: paju; metsätuhot; mänty; koivu; hirvi; taimikkotuhot; talviravinto; hirvituhot
English keywords: Scots pine; seedling damage; Alces alces; nutrition; moose; forest damage; elk; elk damage
Abstract | View details | Full text in PDF | Author Info

Increase in the elk (Alces alces L.) population and the problems of its grazing has called for detailed research. The present study concentrated on three observation areas representing northern, western and eastern parts of Finland. There were 28 field observers watching 68 elks.

Earlier investigations in Finland indicate that aspen (Populus tremula L.) is the staple diet of elk. This study reached different conclusions, probably largely because of aspen is gradually becoming an increasingly rare tree species in Finland. According to this study, the principal food of elk in the winter is willow (Salix sp.). In the whole country, willow accounts for about 70% of elk’s nutrition. In the Far North the percentage is approx. 90. Of the other tree species, the order of preference is: aspen, Scots pine, mountain ash, juniper and birch. In addition, in Western Finland where snow is less deep, lingonberry and blueberry shrubs are on the menu. Beard moss on the spruce was frequently eaten locally. Elk seems to have eaten mainly the last annual shoot of trees and bushes. In few cases it has gnawed the bark of Scots pine, aspen and willow. Elk consumes in average 340 twigs or terminal shoots per day in the winter. This corresponds to about 1.8 kg of food.

The problem of elks damaging Scots pine seedlings has been observed in Western Finland, were the elk population is higher. The article suggests that suitable feeding places would be left for elk in places that are unsuitable for agriculture or forestry. Leaving, for instance, birch seedlings in Scots pine stands has been noticed to attract elks and to increase the damage to pine.

The article includes an abstract in English and a summary in Swedish.

  • Sainio, E-mail: ps@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 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 4544, category Article
V. K. Ahola. (1938). Näkökohtia taimien kasvatuksesta. Silva Fennica no. 46 article id 4544. https://doi.org/10.14214/sf.a13953
English title: Production of forest tree seedlings.
Original keywords: metsäopetus; metsänhoitajien jatkokurssit; taimitarha; taimituotanto; metsäpuun taimet; taimikasvatus
English keywords: forest nursery; forest education; professional development courses; tree seedlings
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 production of forest tree seedlings.

  • Ahola, E-mail: va@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 4488, category Article
V. K. Ahola. (1937). Taimitarhatöistä. Silva Fennica no. 39 article id 4488. https://doi.org/10.14214/sf.a13898
English title: Forest nurseries in Finland.
Original keywords: metsäopetus; metsänhoitajien jatkokurssit; taimitarha; taimituotanto
English keywords: forest education; professional development courses; forest nurseries; tree seedlings
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 cultivation of seedlings in forest nurseries.

  • Ahola, E-mail: va@mm.unknown (email)
article id 4458, category Article
Esko Kangas. (1931). Siikakankaan mäntytaimistojen tuhoista. Silva Fennica no. 17 article id 4458. https://doi.org/10.14214/sf.a8999
Keywords: seedling damage; planting; seedling stand; insect damage; fungal diseases; sowing
Abstract | View details | Full text in PDF | Author Info

Regeneration of large open areas in dry mineral soil forest sites that usually grow Scots pine (Pinus sylvestris L.) have several problems. For instance, soil frost, snow, ground vegetation and dryness can prevent germination and growth of seedlings. The damages caused by insects and fungi in seedlings of a large burned area in Siikakangas in Southern Finland was studied. A forest fire burned the area nearly completely in 1909, and 310 hectares have been sowed or planted with mostly Scots pine during the following years. Minor areas have been regenerated with Pinus montana Noll, Pinus excelsa Lamb., Pinus murrayana Balf. and Larix sibirica Ledeb.

No completely healthy pine seedling stands could be found in the area. About 41% of the seedlings in the sample plots were damaged. The most common causes for damage were Evetria resinella (now Retinia resinella L.), Luperus pinicola (now Calomicrus pinicola (Duft.)), Pissodes notatus (now Pissodes castaneus Degeer), Evetria turionana Hb. and Hylobious abietis L. The most usual fungal disease was Lophodermium sp. Evetria resinella caused damages in all the area. Evetria turionana, Pissodes notatus and Hylobius abietina were found in the older seedling stands. Other damages were more localized. The slacks in the terrain seemed to have most damages, the original cause being probably soil frost. Some damages, as Lophodermium, were related to the density of the seedlings, especially in the sown areas. Cleaning of seedling stands could decrease these damages. Planting seems to have succeeded better than patch sowing.

The PDF includes a summary in German.

  • Kangas, E-mail: ek@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 7173, category Article
Erkki Lähde. (1966). Studies on the respiration rate in the different parts of the root systems of pine and spruce seedlings and its variations during the growing season. Acta Forestalia Fennica vol. 81 no. 8 article id 7173. https://doi.org/10.14214/aff.7173
Keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; seedlings; respiration; seasonal variation; respiration of roots; respiration rate; short-roots; long-root
Abstract | View details | Full text in PDF | Author Info

In this study an attempt was made to use manometric Warburg technique in studying the growing season variations in the respiration rates of the roots of 1–3-year-old seedlings of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.). The respiration rates in both short-roots and long-roots have also been investigated.

According to the results, respiration intensity was the greatest in Scots pine and Norway spruce short-roots but also considerable in the long-root tips at the points of elongation. When the oxygen uptake rate per weight unit in the pine short-roots is given value of 100, the rate in the long-root tips is 61 and in the basal area 36. The corresponding values for spruce are 100, 69 and 43. The relative carbon dioxide release rates are different for the basal parts of the long-roots: pine 53 and spruce 57, when the CO2 release from the short-roots is 100. The CO2 release rate in the basal parts of the long-roots is relatively greater than the oxygen uptake. The respiration rate of the root systems of pine was larger than that of spruce due to the larger size of the root system.

The respiration rate per unit weight of pine roots of the 1- to 3-year-old seedlings decreases significantly with the increasing age. In spruce, the decrease was smaller. The result could have been different if only the short-roots of the same growing season were studied from all seedlings.

During the first growing season the root respiration rate decreased from the middle of the summer towards autumn. An experiment with pine seedlings grown in the mineral soil showed a very rapid increase in respiration rate in the spring. The rate, especially oxygen uptake, is at its greatest in the roots at the time of fastest growth.

  • Lähde, E-mail: el@mm.unknown (email)
article id 7166, category Article
J. E. Hårdh. (1966). Trials with carbon dioxide, light and growth substances on forest tree plants. Acta Forestalia Fennica vol. 81 no. 1 article id 7166. https://doi.org/10.14214/aff.7166
Keywords: Pinus sylvestris; Betula pendula; Picea abies; Scots pine; silver birch; seedlings; carbon dioxide; growth hormones; growth studies; tree nursery; Norway sprce
Abstract | View details | Full text in PDF | Author Info

Growth-promoting effects of enhanced caron dioxide levels upon forest tree seedlings grown in plastic houses was studied in 1964 and 1965 in the Forest Breeding Foundation in Haapastensyrjä near Loppi in Southern Finland. In both years more vigorous height and weight growth, and development of root system was achieved when the CO2 concentration was increased to 0.2% than in the normal conditions (CO2 0.03%). The CO2 concentration was increased by burning propane in the plastic houses. Burning continued for four hours per day either at 8–10 and 14–16 a clock or 6–10 a clock. Growth was not affected by the time of the treatment, and it was equally high in 0.1% and 0.2% concentrations.

Treatment of the seedlings with 100–200 ppm gibberellic acid (GA) increased the height growth of healthy, well-rooted seedlings. Treatment with a concentrated (600 ppm) dosage, as well as treatment with a combination of GA and 1-naphtyl acetic acid (NAA) caused serious defects in grafts of Scots pine (Pinus sylvestris L.). GA treatments did not induce flower formation in pine. Red light during the night seemed to enhance growth of grafts of silver birch (Betula pendula Roth) and Norway spruce (Picea abies (L.) H. Karst.).

The PDF includes a summary in Finnish.

  • Hårdh, E-mail: jh@mm.unknown (email)
article id 7161, category Article
Olavi Laiho. (1965). Further studies on the ectendotrophic mycorrhiza. Acta Forestalia Fennica vol. 79 no. 3 article id 7161. https://doi.org/10.14214/aff.7161
Keywords: Pinus sylvestris; Scots pine; Finland; tree species; distribution; Europe; ecology; mycorrhiza; seedlings; tree nurseries; occurrence; America
Abstract | View details | Full text in PDF | Author Info

There has not been complete agreement as to what is meant by ectendotrophic mycorrhizae, and there is a wide variety of opinion among authors on mycorrhizal terminology. In this paper ectendotrophic mycorrhizae are defined to be short roots with Hartig net and intracellular hyphae in the cortex. A mantle and digestion of intracellular hyphae may be found but are not necessary. In the study of Mikola (1965) ectendotrophic mycorrhiza was found to be common in Scots pine (Pinus sylvestris L.) seedlings in Finnish nurseries. The mycorrhizae had always similar structure and the mycelium isolated from the seedlings (E-strains) was similar. The aim of this study was to find out what kind of ectendotrophic mycorrhizae exist in forests and nurseries outside Finland, what kind of mycorrhizae do the E-strains isolated from Scots pine form with other tree species, and are these associations symbiotic.

Only one type of ectendotrophic mycorrhiza was found on the 600 short roots collected from the continents of Europa and America. The type was similar to the one described by Mikola: the mycelium is coarse and forms a strong Hartig net, and intracellular infection is heavy. Evidence is convincing that this structure was formed by the same fungus species. The species is unidentified. Mycorrhizae synthesized by E-strain with six spruce species, fir, hemloch and Douglas fir were all ectotrophic.

The E-type ectendotrophic mycorrhizae proved to be a balanced symbiosis. The seedlings of 13 tree species inoculated with the E-strain grew in the experiment better than the controls. The observation that ectendotrophic mycorrhizae dominates in the nurseries but is seldom found in forests, and then only in seedlings growing in the forest, was confirmed in the study. In synthesis experiments E-strain formed either ecto- or ectendotrophic mycorrhiza depending on the tree species.

  • Laiho, E-mail: ol@mm.unknown (email)
article id 7160, category Article
Peitsa Mikola. (1965). Studies on the ectendotrophic mycorrhiza of Scots pine in Finland. Acta Forestalia Fennica vol. 79 no. 2 article id 7160. https://doi.org/10.14214/aff.7160
Original keywords: mänty; taimet; mykorritsa; ektendomykorritsa; esiintyminen
English keywords: Pinus sylvestris; Scots pine; Finland; mycorrhiza; seedlings; tree nurseries
Abstract | View details | Full text in PDF | Author Info

The differences between different types of mycorrhiza; endomycorrhiza, ectomycorrhiza and ectendomycorrhiza, and the use of the terms have been variable in the earlier research. Studied of mycorrhiza in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seedlings may suggest that the conditions affect which kind of mycorrhiza develops in the seedlings. This study is aimed mainly at finding out whether the difference of ectotrophic and ectendotrophic mycorrhizae depends on fungal symbionts or envirionmental conditions. Furthermore, the occurrence of ectendotrophic mycorrhiza in Finland under various conditions was studied, and experiments on the physiology and ecology of the mycorrhiza and the fungal partner were conducted.

The ectendotrophic mycorrhiza as described in this paper has proved to be very common on Scots pine in Finnish nurseries, but it was not found in Norway spruce seedlings. The results did not support the hypothesis presented in some earlier studies that ectendotrophic mycorrhiza is more parasitic than the other mycorrhizal fungi. The nursery survey showed that no correlation existed between the size and vigour of the seedlings and the presence of ectendotrophic mycorrhiza. Furthermore, greenhouse-grown seedlings with and without the fungus grew equally well. The type of mycorrhiza was, however, almost exclusively confined to young (1–3-years-old) seedlings and to nursery soils. The experiments indicates also that ectendomycorrhizal fungus has a very wide ecological amplitude in regard to light intensity, soil fertility, acidity, and humus content. It has, however, a weak competitive ability in natural forest soils against the indigenous fungal population. When the seedlings were transplanted from the nursery to forest soil, their mycorrhizal population was largely changed.

  • Mikola, E-mail: pm@mm.unknown (email)
article id 7158, category Article
Olavi Huuri. (1965). Männyn- ja kuusenkäpyjen varastoinnin vaikutus niistä saatavan siemenen itävyyteen. Acta Forestalia Fennica vol. 78 no. 5 article id 7158. https://doi.org/10.14214/aff.7158
English title: The effects of storage in cones on the viability of pine and spruce seeds.
Original keywords: kuusi; mänty; itävyys; kävyt; siemenkeräys; käpyjen varastointi; metsäpuiden siemenet; siementen varastointi; karistus; itämiskyky
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; cones; seeds of forest trees; seed extraction; storage of cones; storage of seeds; germinative capacity
Abstract | View details | Full text in PDF | Author Info

Seed storing experiments with cones of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) were conducted in Oitti seed extracting plant in Southern Finland from February to December 1955. The pine cones were stores for 267 and the spruce coned for 304 days. In four of the storage methods the cones were packed in sacks and another four in wooden boxes. Sample of cones were taken once a month, seeds were extracted and the germinative capacity was tested. The remaining extracted seeds were placed in storage, and in January 1956 moved to cold seed cellar until 1962, when the viability of the seeds was tested.

According to the results, cleaned pine cones can be stores for at least nine months using almost all methods of storage which are commonly used at our seed traction plants, without hazarding the usability of the seeds. The seeds in spruce cones, however, seemed to be more sensitive to conditions during the storage. The germinative capacity of the spruce seeds began to decrease after the beginning of May. Later the seeds were infected with mould, which increased towards the end of the experiment.

Thus, preservation of the germinative capacity of the seeds of pine and spruce requires storage in different conditions. The results suggest that extraction of spruce seeds should be finished during the cold winter months. It seems that seed in the cones of pine and spruce endure storage in piles of paper or cloth sacks at least as well as in wooden boxes. Occasional warming of the storage, snow and foreign material among the cones and an over meter thick cone layer decreased the germinative capacity of spruce seeds during spring and summer. Spruce seeds that had been extracted immediately after collecting of the cones preserved their germinative capacity well during an eight years storage period.

The PDF includes a summary in English.

  • Huuri, E-mail: oh@mm.unknown (email)
article id 7151, category Article
Peitsa Mikola, Olavi Laiho, Jorma Eerikäinen, Kari Kuvaja. (1964). The effect of slash burning on the commencement of mycorrhizal association. Acta Forestalia Fennica vol. 77 no. 3 article id 7151. https://doi.org/10.14214/aff.7151
Keywords: Pinus sylvestris; Scots pine; mycorrhiza; seedlings; prescribed burning; sowing
Abstract | View details | Full text in PDF | Author Info

Prescribed burning is a common silvicultural practice in northern Europe, intended to destroy the slash and ground vegetation and to reduce the thickness of the raw humus layer prior reforestation. The purpose of the experiments was to study whether there are any differences in the commencement and early development of mycorrhizal infection between burned and unburned areas. A clear-cutting area was burned on May 1961. The soil was rocky moraine, the forest type was Vaccinium type. Two weeks after burning Scots pine (Pinus sylvestris L.) was sown in patches.

According to the results, mycorrhizal infection took place on the unburned area earlier than on the burned. The difference was relatively small, perhaps 1–2 weeks. Although burning kills mycorrhizal fungi, it did not cause serious harm to the seedlings, on the contrary, the favourable influence of burning was more distinct. The high temperatures caused by the fire are restricted in the soil in a prescribed burning only a few centimetres deep. Although the mycorrhizal fungi are concentrated in a very thin surface layer of the soil, some mycorrhizae are situated deeper, and from there the fungi are able to infect roots and spread back to the surface layer. The fire also rises the pH of the soil, which can be harmful for mycorrhizal fungi. Even this effect, however, is limited to a thin surface layer.

The PDF includes a summary in Finnish.

  • Mikola, E-mail: pm@mm.unknown (email)
  • Laiho, E-mail: ol@mm.unknown
  • Eerikäinen, E-mail: je@mm.unknown
  • Kuvaja, E-mail: kk@mm.unknown
article id 7150, category Article
Olavi Laiho, Peitsa Mikola. (1964). Studies on the effect of some eradicants on mycorrhizal development in forest nurseries. Acta Forestalia Fennica vol. 77 no. 2 article id 7150. https://doi.org/10.14214/aff.7150
Keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; mycorrhiza; herbicide; seedlings; tree nurseries; eradicants; fungicide
Abstract | View details | Full text in PDF | Author Info

Mycorrhizal association is a characteristic feature of the trees of the northern coniferous forests. The purpose of the present study was to determine what influence some fungicides and herbicides regularly used in Finnish nurseries have on formation and development mycorrhizal in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seedlings. The results are based mainly on field experiments in nurseries. First the initiation of mycorrhiza was described in untreated seedlings.

In the first growing season mycorrhizal infection commences fairly late even under normal conditions, i.e. 6–7 weeks after seeding and 3–4 weeks after the formation of the first short roots. Soil disinfectants are commonly used in nurseries before seeding, and they are supposed to evaporate or disintegrate in a few days or 1–2 weeks. In pure culture experiments mycorrhizal fungi proved several times more sensitive than parasitic and indifferent soil moulds to herbicides and fungicides, but in field experiments the delay of mycorrhizal infection caused by them does not seem to harm the seedlings. In the second summer differences of mycorrhizal relations between treated and control plots disappeared. Accordingly, the influence of biocides on mycorrhizae, when applied in the customary concentrations, does not extend beyond the first growing season.

Methyl bromide and SMDC retarded mycorrhiza formation distinctly, while formaldehyde and allyl alcohol had no effect. Apart from not retarding mycorrhizae, formaldehyde and allyl alcohol promoted seedling growth and favoured Trichoderma viride in the soil. Trichoderma is known to be antagonistic to many fungi.

The PDF includes a summary in Finnish.

  • Laiho, E-mail: ol@mm.unknown (email)
  • Mikola, E-mail: pm@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 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 7486, category Article
Paavo Yli-Vakkuri. (1959). Siemensiipien hankaajista ja niiden vaikutuksesta siemenen itävyyteen. Acta Forestalia Fennica vol. 68 no. 4 article id 7486. https://doi.org/10.14214/aff.7486
English title: On machines for abrading seed wings and their influence on the germinative capacity of the seed.
Original keywords: kuusi; mänty; laitteet; metsäpuiden siemenet; karistamot; siemensiivet; siemensiipien hankaajat
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Socts pine; seeds of forest trees; seed extraction; seed wings
Abstract | View details | Full text in PDF | Author Info

This paper deals with two machines designed for abrading seed wings, and their influence on the germinative capacity of seed of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.). Both machines are commonly used in Finland.

The results of the study indicate that the act of abrading may cause slight or even serious injuries to the seed. Slight injuries of about 3% are probably not easily avoided if mechanical abrading is resorted to. It must be noted, however, that even this reduction in germinative capacity causes significant yearly loss. If the reduction in germinative capacity is greater, which seems to be possible, it is advisable to test the mechanism of the machine and its method of abrading. As the clearance of the machines can affect the extent of injuries, all machines should be tested. If possible, a continual operation control should be arranged. It could, at the same time, to supply material for improving the abrading method and equipment.

The PDF includes a summary in English.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
article id 7475, category Article
Peitsa Mikola. (1958). Liberation of nitrogen from alder leaf litter. Acta Forestalia Fennica vol. 67 no. 1 article id 7475. https://doi.org/10.14214/aff.7475
Keywords: Pinus sylvestris; Scots pine; seedling growth; seedlings; litter; alder; soil improvement; Alnus sp.
Abstract | View details | Full text in PDF | Author Info

Litters of different plant species vary greatly in regard to their nutrient content and other properties. The aim of the study was to compare different litters from the standpoint of their value as soil fertilizer. In an experiment Scots pine (Pinus sylvestris L.) seedlings were grown in pot cultures in which known amounts of different litters had been mixed with the soil. The tested litters were Pinus sylvestris (L.), Larix sibirica (Ledeb.), Betula sp., Populus tremula (L.), Alnus incana (L.) Moench, A. glutinosa (L.) (Gaertn.), Sorbus aucuparia (L.), Tilia cordata (Mill.), Acer platanoides (L.), Corylus avellana (L.), Eupteris aquilina (L.), and Deschampsia flexuosa (L.) Trin.

A striking difference was found between alder (Alnus sp.) leaf litter and all the other litters tested. The difference can be seen from the second growth season on, becaus the young seedling uses mainly the nutrients included in the seed. The leaf litter has mainly unfavourable effect on the growth of the pine seedlings. Only both alder species improve the growth. This is mainly due to the nitrogen content of alder leaves. Tree leaves and other forest litter are often composted in the forest nurseries. It seems that adding nitrogen to the compost is necessary, otherwise compost added to the soil may have a harmful effect on the seedlings. Alder, on the other hand, has nitrogen binding Actinomyces growing in symbiosis in its root nodules, and is able to utilize atmospheric nitrogen.

The PDF includes a summary in Finnish.

  • Mikola, E-mail: pm@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 7452, category Article
Olli Vaartaja. (1955). Factors causing mortality of tree seeds and succulent seedlings. Acta Forestalia Fennica vol. 62 no. 3 article id 7452. https://doi.org/10.14214/aff.7452
Keywords: seedling damage; seeds; drought; heat tolerance; soil types; germling
Abstract | View details | Full text in PDF | Author Info

Germlings and small tree seedlings are exposed to extreme conditions in the forest floor. In this study the influence of climatic factors to seeds and seedlings were studied experimentally, and an attempt was made to estimate the importance of various factors in several sowing experiments in Finland.  

Seeds of Scots pine (Pinus sylvestris L.) were subjected to temperature variations which simulated those of exposed forest sites. The seeds lost some of their germinative capacity during the five-day treatments. Succulent seedlings died when subjected to immersion for 15 minutes at temperatures from 51.5 to 55 ºC. After a hardening pretreatments the seedlings tolerated 2-3 ºC higher temperatures. In artificial humus soil exposed to strong insolation for 15 minutes, temperatures in the range of 54-65 ºC proved to be critical for the seedlings. In natural conditions, also little lower temperatures may prove fatal. Exposure of succulent seedlings of Scots pine and Norway spruce (Picea abies (L.) Karst.) to insolation showed that most damage occurred on humus, quartz sand, and humus-sand mixture, due to rapid evaporation. Seeds of Scots pine, Norway spruce, Betula pendula and Betula pubescens tolerated poorly drought if germination had progressed to a 5–10 mm long radicle. Succulent seedlings tolerated 53-77 days long drought better in humus than in fine silty sand. Seedlings of Pinus sylvestris, Picea abies, Alnus incana and A. glutinosa tolerated cold variably. The developmental stage of the seedling affected cold resistance. Pine seeds sown in furrows germinated well after rain and the survival was high. Frost heaving, snail and insects caused some damages. Germination was lowest at the shallowest furrows. Sowing on natural surfaces gave poor results. Largest damages were caused by birds and ants. 

 The PDF includes a summary in Finnish.  

  • Vaartaja, E-mail: ov@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 7432, category Article
Ukko Rummukainen. (1954). Männyn ja kuusen käpysadosta ja sen arvioinnista vuosina 1950-1953. Acta Forestalia Fennica vol. 61 no. 20 article id 7432. https://doi.org/10.14214/aff.7432
English title: Estimation of Scots pine and Norway spruce cone crop in 1950-1953.
Original keywords: kuusi; mänty; käpysato; siemenkeräys; käpykeräys; arviointimenetelmä
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; seed collection; cone crop; cone collection; assessment method
Abstract | View details | Full text in PDF | Author Info

The cone crop of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) has been assessed in Finland since 1930 annually by sending a questionnaire to forest professionals around the country. Based on the result it is decided if the crop is good enough for collection of the cones next winter. This article presents the results of cone surveys in 1950-1953, and suggest improvements in the method of the investigation.

According to the survey, Scots pine crop was best in 1952, when the crop was intermediate in the whole country, and relatively abundant in the county of Lapland. Norway spruce crop was best in 1951, when the crop was better than in average in the whole country. The evaluators had variable opinions whether the crop was good enough for cone collection or not. They assessed the pine cone collection more often as profitable than the spruce cone collection. Usual reasons to regard spruce cone collection as unprofitable were seed damages and the sites being too far away. To make the results more uniform and accurate, a suggestion to change the evaluation method is presented. The evaluation should be focused on the cone crop of mature stands.

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

  • Rummukainen, E-mail: ur@mm.unknown (email)
article id 7421, category Article
Olli Heikinheimo. (1954). Taimitarhan maantieteellinen sijainti, siemenen alkuperä ja istutuskaudet. Acta Forestalia Fennica vol. 61 no. 9 article id 7421. https://doi.org/10.14214/aff.7421
English title: Geographical location of a tree nursery, seed origin and planting seasons.
Original keywords: taimitarha; taimituotanto; istutus; alkuperä; istutusaika; siemenet; siemenen alkuperä; istutuskausi
English keywords: planting; seedling production; seeds; provenience; tree nursery; planting time
Abstract | View details | Full text in PDF | Author Info

Planning of large central tree nurseries, which has become topical in Finland, means that the seedlings will be used in a wide geographical area. The nursery must decide which proveniences of seeds of the different tree species it will use. This concerns also the customer that buys the seedlings. The planting and lifting of the seedlings in the nursery have to be timed so that the seedlings are in a right state of growth at the time of planting.

The growth of the seedlings can, under certain conditions, be promoted by using a slightly southerly seed provenience, and large-sized seeds. There are, however, limitations to how much the seeds can be transferred northwards. If the nursery lies much south of the planting site, the seedlings have started height growth at the time of planting. This applies especially larch (Larix sp.), Scots pine (Pinus sylvestris L.) and birch (Betula sp.), but affects less Norway spruce (Picea abies (L.) Karst.). The problem can be handled by using a cool storage space for the seedlings waiting for a delivery in the nursery.

According to an international study, seedlings grown from seeds collected in countries south from Finland usually die already during the first two years in the nursery. Within Finland the seeds can be transferred at least by two latitudes. Spruce seems to tolerate longer transfer. Seed orchards should be planted south of the seed’s origin to ensure better yield and better quality seeds.

The Silva Fennica issue 61 was published in honour of professor Eino Saari‘s 60th birthday.
The PDF includes a summary in German.

  • Heikinheimo, E-mail: oh@mm.unknown (email)
article id 7407, category Article
Olli Vaartaja. (1951). Alikasvosasemasta vapautettujen männyn taimistojen toipumisesta ja merkityksestä metsänhoidossa. Acta Forestalia Fennica vol. 59 no. 3 article id 7407. https://doi.org/10.14214/aff.7407
English title: On the recovery of released Scots pine undergrowth and its silvicultural importance.
Original keywords: mänty; alikasvos; taimikko; kasvu; laatu; ylispuuhakkuu; ylispuut
English keywords: Pinus sylvestris; Scots pine; seedlings; undergrowth; hold-overs; removal of hold-overs; felling of standards
Abstract | View details | Full text in PDF | Author Info

There are contrary opinions on the ability of Scots pine (Pinus sylvestris L.) seedlings to withstand oppression by hold-overs and recover after their felling. The recovery potential of oppressed pine stands in Southern and Northern Finland was studied using two kinds of material, fully recovered Scots pine stands and stands recently released. The volume and volume increment of the stand were measured, and the health of the sample trees was determined.

The study showed that those released pine stands that had been in oppressed state very long (25-60 years) had recovered after clear-cutting. After the release the stands grew at first slowly, but after recovery at about the same rate as natural normal stands of a similar height. The smaller, younger, and less stunted the seedlings were when they were released, and the better the site, the faster was the recovery. At the base of released pine stands various defects was detected. When the trees were released, the defects decrease their technical value. A heavy partial cutting had generally a disadvantageous effect on the stand. Recovering seedlings were found clearly to hinder the development of younger seedlings nearby. This inhibition seemed to be a result of the rapid spread of the root system of released pine trees.

The PDF includes a summary in English.

  • Vaartaja, E-mail: ov@mm.unknown (email)
article id 7370, category Article
Erkki K. Kalela. (1942). Männyn taimien juurien suhtautumisesta emäpuun juuriin. Acta Forestalia Fennica vol. 50 no. 17 article id 7370. https://doi.org/10.14214/aff.7370
English title: Roots of a seedling in relation to roots of the mother tree.
Original keywords: juuristo; taimet; kilpailu; latvuskerros; siemenpuut
English keywords: competition; canopy layer; seedlings; seed trees; root system
Abstract | View details | Full text in PDF | Author Info

The study is based on observations in a Scots pine (Pinus sylvestris L.) stand on a dry upland forest site in Karhumäki, where a 10-15-year old seedling stand grew under a hold-overs of larger trees that had been left in the site in a previous felling. The root systems of 80-120 cm tall seedlings growing around single mother trees were unearthed. Root maps were drawn of the root systems of 120 seedlings.

No seedlings grew around old, large hold-overs. It seems that seedlings could not compete with their root system. If the hold-overs were stunted in their growth, seedlings grew also under the canopy of the mother tree. 90% of the seedlings had a tap root. Rest of the roots grew horisontally in the topsoil. Around a vigorous mother tree, the seedlings grew their roots away from the mother tree. Hold-overs that had belonged originally to the lower canopy layer of the old forest did not have similar effect on the root orientation of the seedlings. Their roots had been previously affected by trees of higher canopy layer, later removed in the felling.

The PDF includes a summary in German.

  • Kalela, E-mail: ek@mm.unknown (email)
article id 7367, category Article
Esko Kangas. (1942). Karistuslämmön vaikutuksesta männyn siemenen karisemiseen ja itämiseen. Acta Forestalia Fennica vol. 50 no. 14 article id 7367. https://doi.org/10.14214/aff.7367
English title: Effect of seed extracting temperature on extraction and germination of Scots pine seeds.
Original keywords: mänty; siementuotanto; itäminen; siemenet; karistus; karistuslämpötila
English keywords: Pinus sylvestris; germination; Scots pine; temperature; seeds; seed production; seed extraction
Abstract | View details | Full text in PDF | Author Info

Temperatures needed in extracting Scots pine (Pinus sylvestris L.) seeds is relatively high, however, there is little information on its effect on germination of the seeds. This survey aimed at studying how different temperatures affect both extraction result and germination of Scots pine seeds. Comparisons between different temperatures (20, 30, 40, 50, 60 and 70 ºC) were made from cones collected from same sample trees, three trees in total.

Temperatures 20 and 30 ºC resulted in incomplete opening of the cones, and gave thus smaller amount of seeds. Complete extraction requires at the least the temperature of 40 ºC. The result is slightly better in 50 ºC, but germination of the seeds is little lower. Temperatures 60 and 70 ºC improve the results, but in the cost of germination. The main reason for lower germination percentage was that the higher temperatures release more empty and defective seeds from the cones. Results of different sample trees were different due to, for instance, quality and size of cones. Higher temperatures accelerated the extraction. According to the study, perfect extraction in 40 ºC requires longer extraction time than when the temperature of 50 ºC is used. In practice, 50 ºC temperature or even little higher temperatures can be used when the extraction time is shorter. Decessive factors in choosing the temperature would be the humidity of cones and length of extraction time.

The PDF includes a summary in German.

  • Kangas, E-mail: ek@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 7336, category Article
R. Sarvas. (1937). Kuloalojen luontaisesta metsittymisestä : Pohjois-Suomen kuivilla kankailla suoritettu metsäbiologinen tutkielma. Acta Forestalia Fennica vol. 46 no. 1 article id 7336. https://doi.org/10.14214/aff.7336
English title: Natural regeneration of burned areas. Forest biological study in dry mineral soil sites in Northern Finland.
Original keywords: luontainen uudistuminen; Pinus sylvestris; metsäpalo; Betula sp.; taimikonhoito
English keywords: Norway spruce; birch; Picea abies; forest fire; Socts pine; tending of seedling stands
Abstract | View details | Full text in PDF | Author Info

Natural regeneration has been common in Northern Finland, where forest fires have been usual, and the large areas make artificial regeneration expensive. The regeneration, and for instance tree species composition and density of the stand, cannot been controlled. In Northern Finland there is little demand for Betula sp. which is often abundant in the burnt areas. The unburned forests are generally Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies (L.) H. Karst.) dominated mixed forests with single Betula sp. trees.

The fire destroys birch for the most part in the Vaccinium site type, but the surviving trees produce enough seeds to regenerate the areas. The largest trees of Scots pine usually survive the fires. Pine has good seed years in the north only every 8th or 10th year. Spruce is totally destroyed in the forest fire and the seedlings grow poorly as primary species. The seedling stands are usually dominated by Scots pine and birch, but birch seedlings grow in batches, and do not hinder growth of pine. The drier Calluna site type stands are dominated by Scots pine. Birch seedlings may be abundant in the beginning, but most of them do not survive. Abundant emergent pine trees prevent the growth of seedlings especially in the dry site types, and they should be thinned to guarantee regeneration. Sowing results are better few years after the fire. The birch seedling should be removed from the seedling stands.

The PDF includes a summary in German.

  • Sarvas, E-mail: rs@mm.unknown (email)
article id 7316, category Article
Martti Hertz. (1935). Kuusen juuriston ensi kehityksestä. Acta Forestalia Fennica vol. 41 no. 3 article id 7316. https://doi.org/10.14214/aff.7316
English title: The early development of Norway spruce root system.
Original keywords: kuusi; Picea abies; sirkkataimi; pääjuuri; kasvualusta
English keywords: seedlings; forest site; main root
Abstract | View details | Full text in PDF | Author Info

The development roots of Norway spruce (Picea abies (L.) H. Karst.) seedlings was studied in sample seedlings grown in different kinds of sites. In the early stage, the seedling roots grow primarily length. The main root is usually long. If the growth of the root is hindered, the tip of the root dies, and the root system growing from the original root collar remains relatively small; in these cases, the secondary root system becomes more important. In unfavourable conditions the root branches can early on replace the main root. The main root of a germling seems to be less able to seek for free growing space than the main and side roots of older seedlings. When the growth of the root is blocked by some kind of obstacle, it does not often hinder the growth of the seedling. The type of soil influences strongly how the root system grows. In good soil and in humus the root system is regular and richly branched, while in clay and coarse sand the root system was small. Spahgnum moss was good substrate for seedlings, Dicranum undulatum moss little less good, while the seedlings grew poorly on Pleurozium Schreberi.

The PDF includes a summary in German.

  • Hertz, E-mail: mh@mm.unknown (email)
article id 7231, category Article
Martti Hertz. (1929). Huomioita männyn ja kuusen pituuskehityksen "vuotuisesta" ja vuorokautisesta jaksosta. Acta Forestalia Fennica vol. 34 no. 18 article id 7231. https://doi.org/10.14214/aff.7231
English title: Observations on annual and daily cycles in the height growth of Scots pine and Norway spruce.
Original keywords: kuusi; mänty; taimet; lämpötila; pituuskasvu; kasvukausi; vuotuinen vaihtelu
English keywords: Pinus sylvestris; Picea abies; height growth; temperature; seedlings; growing seasons
Abstract | View details | Full text in PDF | Author Info

The height growth of Scots pine (Pinus sylvestris L.) seedlings were observed in Korkeakoski and Evo in Southern Finland in 1925-1928. The growth was slow in the beginning of the growing season, increased after that to decrease again towards the end of the growing season. The height growth begun in May, reached the fastest growth rates in June, and ended in June-July. According to the earlier studies, the length of the height growth of Scots pine is dependent on the temperature of the previous summer. This study showed that warm temperatures of the same summer promote height growth, and low temperatures slow it down. Also the daily growth fluctuates, being highest during the afternoon and slowest during the early morning. The daily growth is dependent on temperature.

Norway spruce (Picea abies (L.) H. Karst.) begin the height growth in average 9 days later than Scots pine. Compared to pine, the speed of growth in spruce decreases slower towards the late summer.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in German.

  • Hertz, E-mail: mh@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 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 7102, category Article
J. P. Norrlin. (1923). Writings on the flora of south-eastern Tavastia province. Acta Forestalia Fennica vol. 23 no. 3 article id 7102. https://doi.org/10.14214/aff.7102
Keywords: vegetation; flora; Tavastia; phanerogam; seed plant; spermatophyte
Abstract | View details | Full text in PDF | Author Info

The article begins on the page 8/122 of the PDF file.

Data for this paper have been collected during years between 1859 and 1862 in the communes of Asikkala, Hollola, Padasjoki, Lammi and Koski. 

The first part of the text deals with a general presentation of the geographical, biological and cultural conditions of the studied areas. The second part presents the vegetation according their habitats; they are classified by the degree of moisture. The last is further classified as forested areas or open lands. The examination concentrates on phanerogams (seed plants).   

The characteristics of vegetation of forests, open lands and paludified places (swampy or swamp forming places) are presented with the most influential characters and lists of species.   

  • Norrlin, E-mail: jn@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 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 7010, category Article
O. J. Lakari. (1915). Studies on seed years and age-class distribution of pine forests on heathlands of northern Finland. Acta Forestalia Fennica vol. 5 no. 1 article id 7010. https://doi.org/10.14214/aff.7010
Keywords: seed years; age class distribution; age gradation distribution; heathy woodland; heathland
Abstract | View details | Full text in PDF | Author Info

The data has been collected from northern Finland between about 64th and 68th north latitudes, excluding the polar tree line areas. The sample plots have been selected to represents greatest variation of the habitats in altitude, rainfall and other site factors. The selected trees were cut, their age, height, and diameter at various heights examined and possible signs of forest fires noticed. The age of the trees was examined also with microscope. The age class distribution of the sample plots was studied. The determination of historical seed years was based on age class distribution of the sample plots.  

Grouping of the trees into different age classes was too weak a method to make any conclusions about the periodicity or even less about the frequency of the seed years.  There were also noticeable differences in determining the age of the trees between macroscopic and microscopic age examination. There are also differences in the amount of seedlings between different forest types.

The growth of pines in northern Finland is very slow particularly in the young ages but the growth increases after they reach 1,3 meters, which may take up to 30 years. The development of the forest has been similar through last centuries
  • Lakari, E-mail: ol@mm.unknown (email)
article id 7527, category Article
August Renvall. (1913). The periodic variation of the regeneration of pine (Pinus sylvestris) at the polar tree line. Acta Forestalia Fennica vol. 1 no. 2 article id 7527. https://doi.org/10.14214/aff.7527
Keywords: Pinus sylvestris; seed production; reproduction of pine; polar tree line; cone formation
Abstract | View details | Full text in PDF | Author Info

The study deals with the preconditions for natural regeneration of the pine at the polar tree line in northern Finland and Sweden. The data has been collected in three summers from 1909 to 1911 in areas of Inari and Utsjoki in Finland and Kaaresuvanto, Jukkasjärvi und Pajala in Sweden. The yearly variation of seed production of pine is studied and compared with the age of the stand, site factors and weather conditions.

Intensity of reproduction is dependent on different preconditions for pistils and stamens and hence the total reproduction (formation of cones) can vary very much depending on the weather.

According the study, the formation of cones varies yearly and is particularly strong every three to four years.  Supposedly the same model applies to whole polar tree line of the Fennoscandia. There seem to be no difference between northern and southern parts of Scandinavia when it comes to frequency of good cone years though they not always occur in the same years.
  • Renvall, E-mail: ar@mm.unknown (email)
article id 7515, category Article
Vesa Kaarakka. (1996). Management of bushland vegetation using rainwater harvesting in eastern Kenya. Acta Forestalia Fennica no. 253 article id 7515. https://doi.org/10.14214/aff.7515
Keywords: vegetation dynamics; Kenya; drylands; land rehabilitation; rainwater harvesting; seed bank; Prosopis juliflora
Abstract | View details | Full text in PDF | Author Info

Microcatchment water harvesting (MCWH) improved the survival and growth of planted trees on heavy soils in eastern Kenya five to six years after planting. In the best method, the cross-tied furrow microcatchment, the mean annual increment (MAI; based on the average biomass of living trees multiplied by tree density and survival) of the total and usable biomass of Prosopis juliflora (Sw.) DC. were 2,787 and 1,610 kg ha-1 a-1 respectively, when the initial tree density was 500 to 1,667 trees per hectare. Based on survival, the indigenous Acacia horrida Span., A. mellifera (Vahl) Benth. and A. zanzibarica (S. Moore) Taub. were the most suitable species for planting using MCWH. When both survival and the yield were considered, a local seed source of P. Juliflora was superior to all other species. The MAI in MCWH was at best distinctly higher than that in the natural vegetation (163–307 and 66–111 kg ha-1 a-1 for total and usable biomass respectively); this cannot satisfy the fuelwood demand of concentrated populations, such as towns or irrigation schemes.

The density of seeds of woody species in the topsoil was 40.1 seeds/m2 in the Acacia-Commiphora bushland and 12.6 seeds/m2 in the zone between the bushland and the Tana riverine forest. Rehabilitation of woody vegetation using the soil seed bank alone proved difficult due to the lack of seeds of desirable species.

The regeneration and dynamics of woody vegetation were also studied both in cleared and undisturbed bushland. A sub-type of Acacia-Commiphora bushland was identified as Acacia reficiens bushland, in which the dominant Commiphora species is C. campestris. Most of the woody species did not have even-aged population but cohort structures that were skewed towards young individuals. The woody vegetation and the status of soil nutrients were estimated to recover in 15–20 years on Vertic Natrargid soils after total removal of above-ground vegetation.

  • Kaarakka, E-mail: vk@mm.unknown (email)
article id 7670, category Article
Risto Heikkilä. (1991). Moose browsing in a Scots pine plantation mixed with deciduous tree species. Acta Forestalia Fennica no. 224 article id 7670. https://doi.org/10.14214/aff.7670
Keywords: seedling damage; Alces alces; broadleaved trees; feeding behaviour; moose browsing; mixed plantation
Abstract | View details | Full text in PDF | Author Info

The utilization of available food resources by the moose (Alces alces L.) was studied in a Scots pine (Pinus sylvestris L.) plantation containing an admixture of deciduous species. Rowan (Sorbus aucuparia L.) and aspen (Populus tremula L.) were highly utilized compared to pine and both silver birch (Betula pendula Roth) and downy birch (B. pubescens Ehrh.). However, they were not capable of withstanding continuous browsing by moose owing to their diminished biomass. In total, the browsing intensity (number of browsed twigs/tree) on pine and birch was about double of that on rowan and aspen.

The number of browsed twigs per tree increased as the amount of available main branches increased. The number of bites per available branch, as well as the maximum diameter of the bites, decreased as the density of the plantation increased. Silver birch was more used by moose than pubescent birch as well as planted silver birch compared with naturally regenerated trees.

Main stem breakage was especially common in winter 1988, the average height of the pine and birch trees being over two meters. The tops of broken stems were commonly utilized as food. The increase in moose density and the relatively deep snow cover evidently promoted the incidence of serious damage. The number of undamaged trees/ha was greater in dense than in sparse parts of the stand.

The PDF includes a summary in Finnish.

  • Heikkilä, E-mail: rh@mm.unknown (email)
article id 7659, category Article
Ari Lääperi. (1990). Hoidettujen talvilaitumien vaikutus hirvituhoihin mäntytaimikoissa. Acta Forestalia Fennica no. 212 article id 7659. https://doi.org/10.14214/aff.7659
English title: Effect of winter feeding on moose damage to young Scots pine stands.
Original keywords: mänty; hirvituhot; männyntaimikot; talviruokinta
English keywords: Pinus sylvestris; Alces alces; seedling stands; feeding; moose damage; forest plantations
Abstract | View details | Full text in PDF | Author Info

The establishment of moose (Alces alces L.) winter feeding sites, their utilization and their effect on damage to young Scots pine (Pinus sylvestris L.) plantations was studied in Ruokolahti-Imatra area in Eastern Finland in 1987–89. During the period, the density in the area was about 3–5 moose/ 1,000 ha.

Six feeding sites were established by fertilization, offering mineral lics and the tops of aspen and Scot pine and by salting the tops of pine. The moose preferred the feeding site to control areas during both summer and winter. In winter browsing was very heavy, especially in those areas located in or close to traditional wintering areas. In winter no moose were seen in the summer habitats.

The extent of, and fluctuations in moose damage were studied in 47 Scots pine plantations in the immediate surroundings of the feeding sites (29 plantations), control areas (18 plantations) and also 68 randomly selected pine plantations. Before the experiment began in 1987 four plantations had been seriously damaged. During the study period only one plantation was seriously damaged. However, it could not be conclusively proved that damage to the pine plantations had been reduced as a result of the feeding sites. The results of the study can be put into practice elsewhere to create better living conditions for moose in their winter habitats. However, the food offered at the feeding site should be in the right proportion to the number of animals wintering in the area, so that the risk of damage to nearby plantations would be kept as small as possible.

The PDF includes a summary in Finnish.

  • Lääperi, E-mail: al@mm.unknown (email)
article id 7648, category Article
Markku Nygren. (1987). Germination characteristics of autumn collected Pinus sylvestris seeds. Acta Forestalia Fennica no. 201 article id 7648. https://doi.org/10.14214/aff.7648
Keywords: Pinus sylvestris; Scots pine; seed maturation; seed germination; seed dormancy; chilling requirement
Abstract | View details | Full text in PDF | Author Info

Germination tests in varying photoperiod- and temperature-regimes showed that for early autumn collections, germination of Scots pine (Pinus sylvestris L.) seeds is delayed, especially at low incubation temperature (+10°C) and in darkness. The presence of light during germination (8- or 24-hour photoperiod) or high incubation temperature (+20°C) enhanced germination. As autumn proceeded, a greater proportion of seed were able of germinate in darkness and also in low temperature regime. This result was consistent in both populations studied – in seeds from natural stand (Hyytiälä, Southern Finland) and in seeds from the Hyytiälä clone archive trees, growing in the same site.

An attempt was made to relate the development of germinability during autumn to previously accumulated chilling unit (optimum temperature +3.5°C) sum. Germination percent variation in subsequent cone-collection could not, however, be explained with accumulated chilling.

The PDF includes a summary in Finnish.

  • Nygren, E-mail: mn@mm.unknown (email)
article id 7632, category Article
Pekka Kauppi. (1984). Stress, strain, and injury : Scots pine transplants from lifting to acclimation on the planting site. Acta Forestalia Fennica no. 185 article id 7632. https://doi.org/10.14214/aff.7632
Keywords: Pinus sylvestris; Scots pine; planting; seedlings; root desiccation
Abstract | View details | Full text in PDF | Author Info

This paper is the final report of a study on the damage of tree transplants induced before the trees are planted in the field. The injury development is viewed as a transient rather than a ”step-like” process. The main objective of the study is to develop concepts and methods for recognizing and analysing the dynamic aspects of that process. The report consists of three parts: i) characterization of the environments to which the plants are exposed, ii) theoretical part of model development, and iii) experiments with bare-rooted Scots pine (Pinus sylvestris L.) transplants in which the model was applied.

The results of the first part indicate fast temporal variation of the environmental stress factors, and a slow response of the plant in terms of visible injury symptoms. A model is developed in the second part of the paper for analysing the relationship between the fast stress variables and the slow injury variables. The model is employed in the third part of the study for developing experiments in which the transplants were subjected to different stress conditions. The conclusions emphasize the hazardous role of root desiccation. Similar injury development was observed over a range of different planting sites. Controlling high temperatures during the transportation and storage of the plants was introduced as an indirect method for avoiding the risk of root desiccation.

The PDF includes a summary in Finnish.

  • Kauppi, E-mail: pk@mm.unknown (email)
article id 7628, category Article
Eljas Pohtila, Tapani Pohjola. (1983). Lehvästöruiskutuksen ajoitus kasvukauden aikana. Acta Forestalia Fennica no. 181 article id 7628. https://doi.org/10.14214/aff.7628
English title: The timing of foliage spraying during the growing season.
Original keywords: mänty; herbisidit; taimikonhoito; lehdistöruiskutus; havupuutaimikot
English keywords: Pinus sylvestris; Scots pine; herbicides; seedling stands; MCPA; spraying of foliage; clearing of seedling stands; Roundup; DM; softwood seedling stand; hardwood sprouts
Abstract | View details | Full text in PDF | Author Info

An attempt was made in the study to determine the annual periods available for foliage spraying when cleaning Scots pine (Pinus sylvestris L.) dominated seedling stands. The study was made in nine experimental fields which were established in different parts of Finland. The spraying was applied throughout the growing season by DM, MCPA and Roundup. The results were inventoried one year after the treatments.

The results showed that there were big differences both in the destruction of hardwood sprouts and in the survival of pine seedlings due to the time period of the spraying. Threshold points were observed in the range of effect of DM and MCPA. By means of these it is possible to time the spraying treatments in such a way that there remains only slight damage to pine, but hardwood sprouts are destroyed totally. The results varied with Roundup so much, among other things due to rain, that such threshold points could not be determined. This preparation both had a milder effect on the hardwood seedlings and caused slighter damage to pine than the other preparations.

In Sodankylä in Northern Finland, the pines attained a good resistance to arboricides when the efficient temperature sum of the growing season was 550, but in Punkaharju in Central Finland only when it was 850. The seed provenance of the seedlings had an effect on the resistance. The threshold temperature sums of resistance in pine were on the average 70–74% from the long-term average number of degree days at the origin of the seed. The effect on the hardwood trees grew weaker as the long-term average was filled. Resistance of pine followed with a specific lag the lignification of the shoot and the ceasing of the growth of the needles.

The PDF includes a summary in English.

  • Pohtila, E-mail: ep@mm.unknown (email)
  • Pohjola, E-mail: tp@mm.unknown
article id 7616, category Article
Min-Sup Chung. (1981). Flowering characteristics of Pinus sylvestris L. with special emphasis on the reproductive adaptation to local temperature factor. Acta Forestalia Fennica no. 169 article id 7616. https://doi.org/10.14214/aff.7616
Keywords: Pinus sylvestris; Scots pine; flowering; climate; temperature; seed orchards; seed production; location
Abstract | View details | Full text in PDF | Author Info

Flowering time and characteristics of cones and seed development of Scots pine (Pinus sylvestris L.) plus tree clones originating from various parts of Finland and planted (grafts) in Southern Finland (61° 48’ N, 29° 19’ E) were studied during 1976-1978.

The flowering time (in terms of period unit (p.u.) sums for flowering) of the Scots pine plus tree clones showed characteristics specific to each population and the characteristics appear mainly adapted to the local temperature factor within Finland. Generally, the development of floral organs, cones and seed in the spring and summer seasons also showed a temperature dependence in that the reproductive organs are developed rapidly and/or favourably under higher temperature conditions within its optimum range.

In this respect, establishment of northern Scots pine seed orchards in Central or Southern Finland or an optimum flowering, and a favourable seed development with an optimum physiological reproductive isolation from surrounding Scots pine populations can be justified. Problem arising from the north-south transfer of seed orchards and the significance of trees’ growth rhythm are discussed in connection with tree improvement.

The PDF includes a summary in Finnish.

  • Chung, E-mail: mc@mm.unknown (email)
article id 7604, category Article
Jukka Laine, Hannu Mannerkoski. (1980). Lannoituksen vaikutus mäntytaimikoiden kasvuun ja hirvituhoihin karuilla ojitetuilla nevoilla. Acta Forestalia Fennica no. 166 article id 7604. https://doi.org/10.14214/aff.7604
English title: Effect on fertilization on tree growth and elk damage in young Scots pine stands planted on drained, nutrient-poor open bogs in Finland.
Original keywords: ojitus; mänty; kasvu; hirvituhot; lannoitus; taimikot; typpi; nevat; fosfori
English keywords: Pinus sylvestris; fertilization; nitrogen; drained peatlands; Scots pine; growth; phosphorus; seedlings; elk damages; open pogs
Abstract | View details | Full text in PDF | Author Info

An attempt was made in this study to determine which nutrients and in what amounts should be used in the fertilization of Scots pine (Pinus sylvestris L.) seedling stands on nutrient-poor open bogs in order to obtain optimum seedling growth and to minimize the risk of elk damage.

The most important nutrient to improve seedling growth in the experiments was phosphorus. Already rather small amounts produced a significant effect although the effect of higher dosages seemed to be longer lasting. After fertilization also nitrogen gave significant increase in growth. The number of seedlings damaged by elk increased the most on N-fertilized plots. Also, phosphorus increased the occurrence of elk damage, but effect seemed to be related to the better growth and more suitable size of P-fertilized seedlings. The effect of potassium on seedling growth and on occurrence of elk damage was negligible.

The PDF includes a summary in English.

  • Laine, E-mail: jl@mm.unknown (email)
  • Mannerkoski, E-mail: hm@mm.unknown
article id 7595, category Article
Erkki Hallman, Pertti Hari, Pentti K. Räsänen, Heikki Smolander. (1978). Effect of planting shock on the transpiration, photosynthesis, and height increment of Scots pine seedlings. Acta Forestalia Fennica no. 161 article id 7595. https://doi.org/10.14214/aff.7595
Keywords: Pinus sylvestris; photosynthesis; Scots pine; planting; stress; seedlings; drought; transpiration; water deficit
Abstract | View details | Full text in PDF | Author Info

In the experiment Scots pine (Pinus sylvestris L.) seedlings were transplanted out in the field. The effect of the treatments on gas metabolism and daily height increment were examined. The seedlings were 5-year old Scots pine plants growing in clay pots, covered with plastic bags. Transpiration and photosynthetic rates were monitored with open IRGA measuring system for a few days before being subjected to the treatments and for one month after. In addition, the daily amounts of transpired water and daily height increments were measured. A model for the potential rate of each metabolic process was constructed.

Planting and additional exposure had a strong and rather permanent effect on the self-regulation of the processes. This effect is very similar to that caused by water deficit. Exposure makes the disturbance more pronounced. Transpiration of the transplanted seedlings decreased in a few days after planting to less than half of the potential value and that of the exposed ones decreased to a quarter of the potential value. The daily amounts of photosynthesis decreased to half of the potential value. There was no recovery in photosynthesis during the whole monitoring period of four weeks. There was a slight recovery in transpiration about five weeks after transplanting.

Thus, the treatment probably generated stress conditions throughout the whole growing period, which is characterized by strong self-regulation of photosynthesis and transpiration, thus causing an essential decrease in the total amount of CO2 fixed. The photosynthesis was depressed especially at elevated temperatures after planting, as during water deficit. Planting and additional exposure did not produce any detectable changes in the dependence of the growth rate on temperature or in the effect of self-regulation on height growth. On the other hand, the level of growth was decreased as a result of planting out.

The PDF includes a summary in Finnish.

  • Hallman, E-mail: eh@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
  • Räsänen, E-mail: pr@mm.unknown
  • Smolander, E-mail: hs@mm.unknown
article id 7584, category Article
Leo Heikurainen, Jukka Laine. (1976). Lannoituksen, kuivatuksen ja lämpöolojen vaikutus istutus- ja luonnontaimistojen kehitykseen rämeillä. Acta Forestalia Fennica no. 150 article id 7584. https://doi.org/10.14214/aff.7584
English title: Effect of fertilization, drainage and temperature on the development of planted and natural seedlings on pine swamps.
Original keywords: ojitus; mänty; taimet; lannoitus; ojitetut suot; räme; turvekangas; lämpöolot; sarkaväli
English keywords: Pinus sylvestris; fertilization; drained peatlands; Scots pine; temperature; seedlings; ditch spacing
Abstract | View details | Full text in PDF | Author Info

The paper presents some preliminary results of a 10-year-old study the purpose of which is to determine the effect of simultaneous variations in the intensity of drainage and fertilization on the development of planted and natural seedlings on peatlands under various climatic conditions. The development of the Scots pine (Pinus sylvestris L.) seedlings appeared to be better the more intensive the degree of drainage and fertilization used. The increase in the temperature sum had a positive effect on the development of pine seedlings and decreased the mortality rate.

The best growth result was obtained with a 10 m ditch spacing and strong fertilization. As it is difficult to decrease the 10 m ditch spacing for cost reasons, it can be concluded that on such oligotrophic peatlands as were used in this experiment, only an average growth level in the seedling stands can be reached even with the most efficient forest improvement measures. Broadcast fertilization used in the experiment, at least in large doses, increases seedling mortality, as well as the coverage of the ground vegetation, particularly that of cottongrass and fireweed, and also the shrub height, thus increasing competition. It cannot be recommended for afforestation, and today spot fertilization is used. According to this experiment natural seedlings seem once they have recovered after the first years, to grow better than the planted seedlings. This was true especially in the north and in areas, where drainage was not efficient. The height and height growth of the seedlings were to a large extent dependent on the temperature sum.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@mm.unknown (email)
  • Laine, E-mail: jl@mm.unknown
article id 7548, category Article
Leo Heikurainen, Pertti Veijola. (1971). Lannoituksen ja sarkaleveyden vaikutus rämeen uudistumiseen ja taimien kasvuun. Acta Forestalia Fennica no. 114 article id 7548. https://doi.org/10.14214/aff.7548
English title: Effect of fertilization and ditch spacing on regeneration and seedling growth in pine swamps.
Original keywords: mänty; istutus; taimet; lannoitus; turvekankaat; ojitetut suot; taimikuolleisuus; räme
English keywords: Pinus sylvestris; drained peatlands; Scots pine; planting; mortality; seedlings; fertilizing; pine bogs
Abstract | View details | Full text in PDF | Author Info

In 1965 and 1966 a total of 25 experiments were laid out in various parts of Finland in order to find out the effect of simultaneous variation in the intensity of drainage and fertilization on the development of plantations and natural seedling stands of Scots pine (Pinus sylvestris L.) growing on pine swamps. The fertilizer used was Y fertilizer for peat soils, a fertilizer mixture containing 14 % N, 18 % P2O5 and 10 % K2O. It was applied in rates of 500, 1,000 and 1,500 kg/ha. The ditch spacings studied were 10, 20 and 30 m. The present paper is a preliminary report on a series of studies, the experiments will be observation for a total of 15–20 years.

Mortality of the planted seedlings was found to be the higher after the first growing season, the larger the quantity of fertilizer that had been applied. Fertilizing caused an increase in seedling mortality even after the first growing season following application. At the end of the fifth growing season the height of both natural and planted seedlings is the greater, the larger the quantity of fertilizer that has been applied. Analysis of the height growth of the seedlings showed that larger quantities of fertilizer did not increase growth in the same proportion. The occurrence of growth disturbances is the greater, the more fertilizer has been applied.

Fertilization also changed the composition of ground vegetation. The in the beginning of the experiment  birch (Betula sp.) was absent in the area, but was found in the stands the greater abundance the higher application of the fertilizer.

From the viewpoint of growth of the seedlings the best results were obtained with the greatest intensity of fertilization and the narrowest ditch spacing used in the study. The results also show that strong fertilization and a high degree of drainage intensity are not capable of bringing about any particularly good growth on peatlands which originally are relatively poor in nutrients. The growth values now obtained equal only one third of those obtained on peat soils of greater fertility.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@mm.unknown (email)
  • Veijola, E-mail: pv@mm.unknown
article id 7546, category Article
Pentti K. Räsänen. (1970). Nostoajankohdan, pakkaustavan, varastointiajan pituuden ja kastelun vaikutuksesta männyn taimien kehitykseen. Acta Forestalia Fennica no. 112 article id 7546. https://doi.org/10.14214/aff.7546
English title: The effect of lifting date, packing, storing and watering on the field survival and growth of Scots pine seedlings.
Original keywords: mänty; taimet; varastointi; kuolleisuus; kastelu; nostoaika
English keywords: Pinus sylvestris; Scots pine; planting; mortality; storage; seedlings; watering; lifting time
Abstract | View details | Full text in PDF | Author Info

This study was carried out in 1966 in the nursery at Hyytiälä, Korkeakoski Forest District, in Southern Finland. The influence of lifting date (two liftings), way of packing (two methods) and length of storage (one, three and six weeks) on the development of Scots pine (Pinus sylvestris L.), 2 + 1, during the four years following planting was assessed. On the seedlings stored for six weeks, the influence of compensating for the water deficit was also studied.

According to the results, the lifting carried out later, i.e. when the seedlings had already started growth, gave slightly better results than when seedlings were lifted earlier. No difference could be observed for seedlings stored for one week, but for the seedlings stored for three or six weeks, mortality in the lot lifted earlier was 6- to 7-fold that of the seedlings lifted later. The main reason for this was probably that the seedlings of the earlier lifting suffered from lack of water at the time of lifting.

The growth of the seedlings lifted earlier and stored for three weeks showed a decrease compared to those lifted later. For the seedlings stored for six weeks, on the other hand, faster growth was recorded for both the seedlings of the earlier and the later lifting in comparison with those stored for shorter times. Watering increased to some extent the growth of the seedlings stored for six weeks.

During the normal, one- and three-week storing periods, seedlings were well preserved when packed both in bundles and in polythene sacks. Three years after the planting the average mortality was about 10%. Effect of watering was large for those seedlings that had been longer in the storage.

The PDF includes a summary in English.

  • Räsänen, E-mail: pr@mm.unknown (email)
article id 7602, category Article
P. M. A. Tigerstedt. (1969). Progeny tests in a Pinus silvestris (L) seed orchard in Finland. Acta Forestalia Fennica no. 99 article id 7602. https://doi.org/10.14214/aff.7602
Keywords: Pinus sylvestris; Scots pine; heritability; seedlings; progeny
Abstract | View details | Full text in PDF | Author Info

Heritability of first and second-year height growth of Pinus sylvestris (L.) plants was studied using three different mating designs. Plants grew in a plastic greenhouse during the first growth period. During the second growth period they were exposed to open air conditions.

Heritability values varied from zero to 42%. An average heritability based on six separate calculations (two from each mating design) was computed and its reliability was discussed. This heritability value was 18%.

Different ways of improving heritability estimates was discussed and the need of more investigations on trait quality in relation to fitness and on the effect of natural selection and population strategy was emphasized.

  • Tigerstedt, E-mail: pt@mm.unknown (email)
article id 7608, category Article
Peitsa Mikola. (1969). Comparative observations on the nursery technique in different parts of the world. Acta Forestalia Fennica no. 98 article id 7608. https://doi.org/10.14214/aff.7608
Keywords: Finland; New Zealand; substrate; forest nurseries; nurseries; methods; Africa; potted seedlings; greenhouses; Mediterranean countries; Australia; Latin America
Abstract | View details | Full text in PDF | Author Info

This paper is a report of the authors visits to over 80 forestry nurseries in 20 countries mostly in the tropics or subtropics. The article aim is to describe the methods used in the various countries and compares them to the conventional methods of cool and temperate countries. The article introduces nurseries of Africa south of the Sahara, Mediterranean area, Australian and New Zealand and Latin America.

A complete revolution has taken place in the Finnish nursery practice, which used to raise the seedlings in natural field soil in open-air nurseries. The seedlings were usually transplanted into transplant beds at the age of two years. Now the use of plastic greenhouses of light construction and an artificial soil substrate (fertilized peat) are essential. The new technique has some similarities to the practises of the tropical and subtropical nurseries. In Finland cultivation in greenhouses has hastened the development of the seedlings and shortened the nursery rotation from four to two years, and provided better control of watering and fertilization.

Peat beds in greenhouses are used also in Swaziland. The advantage of peat is that it is free of weed seeds, which eliminates weeding. Peat substrate gives also better yield of seedlings, which decreases the need of seeds, which is important in Finland. Another technique common with tropical silviculture is the production of potted seedlings, which are easy to handle and transport. In tropics, peat pots (jiffy pots) have made it possible to grow plantable seedlings in one season without transplanting. The present Finnish technique means a decreased degree of mechanization compared to the conventional technique of modern European and American nurseries.

  • Mikola, E-mail: pm@mm.unknown (email)
article id 7188, category Article
Paavo Yli-Vakkuri, Pentti K. Räsänen, Asko Hilli. (1968). Taimien talvivarastoinnista ja sen vaikutuksesta männyn taimien istutuskelpoisuuteen. Acta Forestalia Fennica no. 88 article id 7188. https://doi.org/10.14214/aff.7188
English title: Cold-storage and its effects on the field survival and growth of planted Scots pine.
Original keywords: mänty; taimitarha; taimikasvatus; taimet; kylmävarasto; talvivarastointi; taimiviljely
English keywords: Pinus sylvestris; nursery; Scots pine; seedlings; cold storage; winterstorage
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to find out the planting vigour of Scots pine (Pinus sylvestris L.) stored over the winter either in winter storage mainly in the temperature of 4 – -6 °C or in nursery beds. The experimental planting included about 4,500 of 2+1 transplants in Northern Finland. In spring 1965 the control plants were lifted in the spring before budbreak and stored in closed bags in a cold store, in the following year the control plants were lifted in June when the growth had started.

Winter storage of pine transplants in a cold store, tightly closed into bags for the major period, did not, according to the results, increase plant mortality as compared to lifting in the spring. Soaking the stored-plant roots did not affect plant mortality. Mortality was rather small in all treated lots and probably more dependent on planting site and other local factors.

No consistent difference on the leader growth, needle length, bud number and plant grade was found between the plants stored over winter and those lifted in the spring. Sealing the plants into tight bags for winter proved to be suitable method, efficiently preventing water shortage in the plants. No moulds or fungal diseases were found in the plants. In the exceptionally cold 1965–1966 winter, temperature in the cold store sank to -15 °C, but in spite of the temperatures below the recommended storing temperature, the plants survived well. The reason was that the plants froze slowly in the fall and thawed out slowly in the spring.

The value of vigour grade in predicting plant-characteristic development proved to be good, and predicted plant development also in the following year fairly well.

The PDF includes a summary in English.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
  • Räsänen, E-mail: pr@mm.unknown
  • Hilli, E-mail: ah@mm.unknown

Category : Research article

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.
Abstract | Full text in HTML | Full text in PDF | Author Info
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 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.
Abstract | Full text in HTML | Full text in PDF | Author Info
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 (email)
  • 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 10769, category Research article
Harri Mäkinen, Pekka Nöjd, Samuli Helama. (2022). Recent unexpected decline of forest growth in North Finland: examining tree-ring, climatic and reproduction data. Silva Fennica vol. 56 no. 4 article id 10769. https://doi.org/10.14214/sf.10769
Keywords: Pinus sylvestris; Picea abies; precipitation; temperature; seed production; tree-ring width; growth variation
Highlights: Tree-ring indices of Scots pine showed decadal variations and a prolonged reduction both on mineral soil sites and peatlands after the mid 2000s; The indices of Norway spruce had less pronounced decadal variations and no trend-like reduction over the last 15 years; Temperature and drought explain some part of the observed growth variability.
Abstract | Full text in HTML | Full text in PDF | Author Info

After a decades-long increasing trend, the recent results of the National Forest Inventory (NFI) reported a decline of forest growth in North Finland. The aim of this study was to assess climatic and reproduction influences behind the growth decline. We used tree-ring data that had been collected by NFI using systematic sampling. The tree-ring width series were detrended using the regional curve standardisation (RCS) removing age-related trends. The resulting tree-ring indices of Scots pine (Pinus sylvestris L.) showed decadal variations with low increment in the 1990s, and high increment in the 1980s and the early years of the current century. Thereafter, a prolonged growth reduction for pine started both on the mineral soil sites and peatlands. The tree-ring indices of Norway spruce (Picea abies (L.) Karst.) had less pronounced decadal variations and no trend-like reduction over the last 15 years. High spring and summer temperatures were found to enhance radial growth, but high winter temperatures were related to low growth for pine and spruce in the following summer. Temperature variation, accompanied by variables indicating years of drought and intensive flowering, accounted for 34% annual growth variance of pine and 21–44% for spruce. Thus, the results imply that climatic factors may have to some extent contributed to the recent growth reduction of pine. Due to its ecological and economic consequences growth decline needs to be further monitored and investigated. Moreover, analyses of stand and age structure, potentially affecting the growth decline, were beyond the scope of this paper, but also warrant further investigation.

  • Mäkinen, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki ORCID https://orcid.org/0000-0002-1820-6264 E-mail: harri.makinen@luke.fi (email)
  • Nöjd, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki E-mail: pekka.nojd@luke.fi
  • Helama, Natural Resources Institute Finland (Luke), Ounasjoentie 6, 96200 Rovaniemi, Finland ORCID https://orcid.org/0000-0002-9777-3354 E-mail: samuli.helama@luke.fi
article id 10663, category Research article
Back Tomas Ersson, Lars-Göran Sundblad, Jussi Manner. (2022). Cost analysis of seedling supply systems adapted for mechanized tree planting: a case study from southern Sweden. Silva Fennica vol. 56 no. 2 article id 10663. https://doi.org/10.14214/sf.10663
Keywords: logistics; silviculture; reforestation; tree planting machine; containerized seedling; seedling handling; system analysis
Highlights: The total cost of cardboard box concepts that increase the productivity of tree planting machines is higher than of the cultivation tray system (5–49% in the basic scenario); Increasing the boxes’ packing densities and/or the planting machines’ hourly cost increases the boxes’ cost-competitiveness; Packing density is a key factor in achieving highly cost-efficient seedling supply systems for mechanized tree planting.
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Because today’s tree planting machines do a good job silviculturally, the Nordic forest sector is interested in finding ways to increase the planting machines’ productivity. Faster seedling reloading increases machine productivity, but that solution might require investments in specially designed seedling packaging. The objective of our study was to compare the cost-efficiency of cardboard box concepts that increase the productivity of tree planting machines with that of today’s two most common seedling packaging systems in southern Sweden. We modelled the total cost of these five different seedling packaging systems using data from numerous sources including manufacturers, nurseries, contractors, and forest companies. Under these southern Swedish conditions, the total cost of cardboard box concepts that increase the productivity of intermittently advancing tree planting machines was higher than the cost of the cultivation tray system (5–49% in the basic scenario). However, the conceptual packaging system named ManBox_fast did show promise, especially with increasing primary transport distances and increased planting machine productivities and hourly costs. Thus, our results show that high seedling packing density is of fundamental importance for cost-efficiency of cardboard box systems designed for mechanized tree planting. Our results also illustrate how different factors in the seedling supply chain affect the cost-efficiency of tree planting machines. Consequently, our results underscore that the key development factor for mechanized tree planting in the Nordic countries is the development of cost-efficient seedling handling systems between nurseries and planting machines.

  • Ersson, SLU, School of Forest Management, SE-739 21 Skinnskatteberg, Sweden ORCID https://orcid.org/0000-0003-2442-7482 E-mail: back.tomas.ersson@slu.se (email)
  • Sundblad, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: lars-goran.sundblad@skogforsk.se
  • Manner, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID https://orcid.org/0000-0002-4982-3855 E-mail: jussi.manner@skogforsk.se
article id 10534, category Research article
Matti Haapanen, Seppo Ruotsalainen. (2021). Adaptive performance of genetically improved and unimproved seedlings of Scots pine. Silva Fennica vol. 55 no. 5 article id 10534. https://doi.org/10.14214/sf.10534
Keywords: Pinus sylvestris; cold hardiness; growth rhythm; seed orchards; bud set; freezing test; reproductive materials
Highlights: We studied the variation in adaptive traits in one-year-old seedlings of Scots pine representing different levels of genetic gain and geographical origins; All the adaptive traits analyzed showed clinal co-variation with the latitude of origin; Differences in adaptive performance between genetically improved and unimproved reproductive materials were mostly small and insignificant when the effect of the latitudinal origin was considered; First-generation seed orchard materials implied slightly poorer autumn frost hardiness compared to other materials, but the results were ambiguous.
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Our main objective was to determine whether various genetically improved reproductive materials of Scots pine (Pinus sylvestris L.) differ in growth rhythm, autumn cold acclimation and resilience from unimproved materials. The study consisted of two successive indoor experiments with Scots pine seedlings representing four levels of genetic gain (unimproved natural stands, first-generation seed orchards, 1.5-generation seed orchards and seed orchards established with freezing-tested parents) and a wide range of geographical origins within Finland. The seedlings were assessed for terminal shoot elongation, growth cessation, bud set, freezing injuries and bud flushing over the first growth period. All the adaptive traits showed a latitudinal trend regardless of the genetic level. Seed orchard progenies and natural stand progenies did not differ significantly in the timing of growth cessation, bud set, and the flushing rate of the frost-injured seedlings, after the trait variation was adjusted to the latitude of origin. The differences in autumn frost hardiness were insignificant, too, except for the somewhat higher injury rate displayed by the first-generation seed orchard materials. The finding was not conclusive due to ambiguous results from the two experiments. Overall, we did not find evidence of alarming compromises in the adaptive performance of genetically improved materials.

  • Haapanen, Natural Resources Institute Finland (Luke), Production systems, Latokartanonkaari 9, FI-00790 Helsinki, Finland ORCID https://orcid.org/0000-0003-3294-501X E-mail: matti.haapanen@luke.fi (email)
  • Ruotsalainen, Natural Resources Institute Finland (Luke), Production systems, Vipusenkuja 5, FI-57200 Savonlinna, Finland ORCID https://orcid.org/0000-0002-2547-0282 E-mail: seppo.ruotsalainen@luke.fi
article id 10509, category Research article
Chuan Xie, Tianfeng Liu, Song Guo, Jian Peng, Zailiu Li. (2021). Effects of ultra-dry storage on seed germination and seedling growth of Handeliondendron bodinieri. Silva Fennica vol. 55 no. 3 article id 10509. https://doi.org/10.14214/sf.10509
Keywords: Handeliodendron bodinieri; priming treatment seed; ultra-dry treatment
Highlights: By reducing the moisture content of the seeds, Handeliodendron bodinieri seeds showed a strong tolerance; PEG played a protective role in the process of re-wetting ultra-dry seeds; Ultra-dry storage could promote Handeliodendron bodinieri seedling growth and root development.
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Handeliodendron bodinieri (H. Lév.) Rehder is a rare, endangered, and therefore, protected tree species native to China. However, there are serious limitations to the effective protection of the species, including a low seed germination-rate and difficult storage due to a high seed oil-content. Here, we evaluated the feasibility of ultra-dry seed storage and its effects on seedling growth. We used the silica gel method to prepare ultra-dry seeds with different moisture contents to find an optimal moisture content range (2.54%–4.77%). Ultra-dry treatment improved storability of H. bodinieri seeds. Furthermore, seeds with a moisture content of 4.77% stored at room temperature, and seeds with a moisture content of 3.97% stored at 4 °C yielded the best results. Priming with an appropriate concentration of polyethylene glycol had a certain repairing effect on ultra-dry stored seeds and improved seed vigor, with a two-day priming treatment with 20% polyethylene glycol having the best effect. Finally, compared with sand storage at 4 °C, ultra-dry storage promoted seedling growth and root development; furthermore, it alleviated storage damage to H. bodinieri seeds, promoted soluble sugar and soluble protein accumulation, and increased seedling nitrogen, phosphorus, and potassium uptake. Therefore, ultra-dry storage can be effectively used to preserve H. bodinieri seeds. Specifically, low-temperature storage of ultra-dry seeds with a moisture content of 3.97% enhanced H. bodinieri seed vigor, and seedling growth and development.

  • Xie, Forestry College, Guangxi University, Daxue E Rd., Xiangtang District, Nanning 530004, Guangxi, China; Huanggang forestry research institute, Huanggang 438000, Hubei, China E-mail: sherman99c@163.com
  • Liu, Forestry College, Guangxi University, Daxue E Rd., Xiangtang District, Nanning 530004, Guangxi, China E-mail: ltfltfll@163.com
  • Guo, Forestry College, Guangxi University, Daxue E Rd., Xiangtang District, Nanning 530004, Guangxi, China E-mail: guosong@gxu.edu.cn
  • Peng, Sanmengjiang forest farm of Guangxi, Liuzhou 545001, Guangxi, China E-mail: pj75481425@126.com
  • Li, Forestry College, Guangxi University, Daxue E Rd., Xiangtang District, Nanning 530004, Guangxi, China E-mail: lizailiu666@163.com (email)
article id 10409, category Research article
Noé Dumas, Mathieu Dassot, Jonathan Pitaud, Jérôme Piat, Lucie Arnaudet, Claudine Richter, Catherine Collet. (2021). Four-year-performance of oak and pine seedlings following mechanical site preparation with lightweight excavators. Silva Fennica vol. 55 no. 2 article id 10409. https://doi.org/10.14214/sf.10409
Keywords: vegetation control; reforestation; seedling growth; seedling survival
Highlights: Mechanical site preparation (MSP) with lightweight excavators controls highly competitive plant species (Molinia caerulea, Pteridium aquilinum) much more efficiently than MSP with conventional methods; This MSP approach improves four-year survival and growth of pine seedlings, but it is less evident for oak seedlings.
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Mechanical site preparation methods that used tools mounted on lightweight excavators and that provided localised intensive preparation were tested in eight experimental sites across France where the vegetation was dominated either by Molinia caerulea (L.) Moench or Pteridium aquilinum (L.) Kuhn. Two lightweight tools (Deep Scarifier: DS; Deep Scarifier followed by Multifunction Subsoiler: DS+MS) were tested in pine (Pinus sylvestris L., Pinus nigra var. corsicana (Loudon) Hyl. or Pinus pinaster Aiton) and oak (Quercus petraea (Matt.) Liebl. or Quercus robur L.) plantations. Regional methods commonly used locally (herbicide, disk harrow, mouldboard plow) and experimental methods (repeated herbicide application; untreated control) were used as references in the experiments. Neighbouring vegetation cover, seedling survival, height and basal diameter were assessed over three to five years after plantation. For pines growing in M. caerulea, seedling diameter after four years was 37% and 98% greater in DS and DS+MS, respectively, than in the untreated control. For pines growing in P. aquilinum, it was 62% and 107% greater in the same treatments. For oak, diameter was only 4% and 15% greater in M. caerulea, and 13% and 25% greater in P. aquilinum, in the same treatments. For pines, the survival rate after four years was 26% and 32% higher in M. caerulea and 64% and 70% higher in P. aquilinum, in the same treatments. For oak, it was 3% and 29% higher in M. caerulea and 37% and 31% higher in P. aquilinum. Herbicide, when applied for three or four years after planting, provided the best growth performances for pines growing in M. caerulea and P. aquilinum and for oaks growing in P. aquilinum. For these species and site combinations, DS+MS and DS treatments reduced the neighbouring vegetation cover for one to four years following site preparation.

  • Dumas, Université de Lorraine, AgroParisTech, INRAE, UMR Silva, 54000 Nancy, France E-mail: noe.dumas@inrae.fr
  • Dassot, EcoSustain, Environmental Engineering Office, Research and Development, 31, rue de Volmerange, 57330 Kanfen, France; Institut National de l’Information Géographique et Forestière, 1 rue des Blanches Terres, 54250 Champigneulles, France E-mail: mathieu.dassot@ign.fr
  • Pitaud, Office National des Forêts, Département Recherche Développement et Innovation, route d’Amance, 54280 Champenoux, France E-mail: jonathan.pitaud@onf.fr
  • Piat, Office National des Forêts, Département Recherche Développement et Innovation, 3 rue du petit château, 60200 Compiègne, France E-mail: jerome.piat@onf.fr
  • Arnaudet, Office National des Forêts, Département Recherche Développement et Innovation, 100 boulevard de la Salle, 45760 Boigny-sur-Bionne, France E-mail: lucie.arnaudet@onf.fr
  • Richter, Office National des Forêts, Département Recherche Développement et Innovation, Boulevard de Constance, 77300 Fontainebleau, France E-mail: claudine.richter@onf.fr
  • Collet, Université de Lorraine, AgroParisTech, INRAE, UMR Silva, 54000 Nancy, France ORCID https://orcid.org/0000-0003-0861-7796 E-mail: catherine.collet@inrae.fr (email)
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 10163, category Research article
Uttam Thangjam, Uttam K. Sahoo, Pentile Thong. (2020). Characterization of morphometric, reproductive and seedling traits of Parkia timoriana in northeast India. Silva Fennica vol. 54 no. 1 article id 10163. https://doi.org/10.14214/sf.10163
Keywords: seed source; heritability; genotype; tree bean; variations
Highlights: Among provenances, Pherema (P1) Serchip (P10) and Jiribam (P7) were associated with stress tolerant and better quality seedlings.; P1 gave the best result for seed traits including high germinability, P10 showed highest seedling vigour, while P7 corresponds to high-quality pod related traits; Variations in morphological, germinative and seedling growth characters of seeds across provenance further illustrate the importance of site selection for the production of better quality trees.
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We studied variations on different traits of Parkia timoriana (D.C.) Merr. in twelve provenances systematically from their source of origin to a controlled environment where representative seedlings were grown. Among the provenances, P1 gave the best result for seed traits including germination traits, P7 for pod traits and P10 for seedling vigour. Effects of seasonal distribution of rainfall and temperature on seed and pod traits were also determined by computing multiple regression analysis. The results displayed winter rainfall and summer temperature as the most important factor determining pod and seed traits. Latitude also significantly (P < 0.001) affected PWT (r = 0.52), SWP (r = 0.46) and SW (r = 0.50). A common garden study for germination and seedling growth indicated P1 and P10 provenance as the best among all. Seeds drawn from P10 gave the highest seedling vigour with an average growth rate of 0.61 cm/day from 90th to 180th day. Highest broad-sense heritability values (h2) were observed in germination traits, followed by seedling collar diameter. The lowest h2 was observed for seedling height.

  • Thangjam, Department of Forestry, School of Earth Sciences & Natural Resource Management, Mizoram University, Aizawl-796004, Mizoram, India ORCID https://orcid.org/0000-0003-1263-5348 E-mail: thangjam1987@gmail.com
  • Sahoo, Department of Forestry, School of Earth Sciences & Natural Resource Management, Mizoram University, Aizawl-796004, Mizoram, India ORCID https://orcid.org/0000-0002-6524-1775 E-mail: uksahoo_2003@rediffmail.com (email)
  • Thong, Department of Forestry, School of Earth Sciences & Natural Resource Management, Mizoram University, Aizawl-796004, Mizoram, India ORCID https://orcid.org/0000-0002-5358-181X E-mail: pentilethong@gmail.com
article id 10230, category Research article
Mohammed Henneb, Osvaldo Valeria, Nelson Thiffault, Nicole Fenton. (2019). Black spruce seedling growth response in controlled organic and organic-mineral substrates. Silva Fennica vol. 53 no. 4 article id 10230. https://doi.org/10.14214/sf.10230
Keywords: Picea mariana; paludification; seedling growth; seedling nutrition; semi-controlled experiment; substrate
Highlights: Seedling height and diameter were highest on clay and mesic substrates respectively; Foliar nutrients were relatively high in seedlings that were established on mesic substrates; We recommend the application of mechanical soil preparation techniques that promote the creation of organic-mesic substrates to support regeneration establishment.
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In the boreal forest of eastern Canada, a large proportion of black spruce (Picea mariana [Mill.] Britton, Sterns & Poggenb.) stands are affected by paludification. Edaphic conditions that are created by paludification processes, including an abundance of microsites with high moisture and low nutrient contents, hinder forest regeneration. Disturbance of paludified sites by mechanical soil preparation (MSP) reduces organic layer thickness, while generating a range of substrates for regeneration establishment. Yet, little information is available regarding the effects of these substrates on tree growth. Our objective was to determine the effect of organic, mineral and organo-mineral substrates that are created following MSP of a paludified site on the growth and root development of black spruce seedlings in a semi-controlled environment. We demonstrated that substrate exerted a significant effect on seedling growth and foliar concentrations of N, P and K. Increase in height and diameter were respectively greatest on clay (mineral) and mesic substrates. Substrate effects did not affect total biomass increases or final root biomass. Foliar nutrients (N, P, K) were relatively high in seedlings that were established on mesic substrates and relatively low for those established on clay substrates. To ensure successful seedling establishment, we recommend the application of MSP techniques that expose organic-mesic substrates on sites that are susceptible to paludification.

  • Henneb, Institut de recherche sur les forêts (IRF), Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada ORCID http://orcid.org/0000-0003-4507-1219 E-mail: mohammed.henneb@uqat.ca (email)
  • Valeria, Institut de recherche sur les forêts (IRF), Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada ORCID http://orcid.org/0000-0002-9921-7474 E-mail: osvaldo.valeria@uqat.ca
  • Thiffault, Institut de recherche sur les forêts (IRF), Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada; Natural Resources Canada, Canadian Wood Fibre Centre, 1055 rue du PEPS, P.O. Box 10380, Stn Sainte Foy, Quebec, QC G1V 4C7, Canada ORCID http://orcid.org/0000-0003-2017-6890 E-mail: nelson.thiffault@canada.ca
  • Fenton, Institut de recherche sur les forêts (IRF), Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada ORCID http://orcid.org/0000-0002-3782-2361 E-mail: nicole.fenton@uqat.ca
article id 9996, category Research article
Mulualem Tigabu, Mostafa Farhadi, Lars-Göran Stener, Per C. Odén. (2018). Visible + Near Infrared Spectroscopy as taxonomic tool for identifying birch species. Silva Fennica vol. 52 no. 4 article id 9996. https://doi.org/10.14214/sf.9996
Keywords: Betula; silver birch; downy birch; seeds; NIRS; OPLS; multivariate modelling
Highlights: Multivariate modelling of visible + near infrared (NIR) reflectance spectra of single seeds distinguished Betula pubescens and B. pendula with 100% and 99% accuracy, respectively; The results demonstrate the feasibility of NIR spectroscopy as taxonomic tool for classification of species that have morphological resemblance.
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The genus Betula L. is composed of several species, which are difficult to distinguish in the field on the basis of morphological traits. The aim of this study was to evaluate the taxonomic importance of using visible + near infrared (Vis + NIR) spectra of single seeds for differentiating Betula pendula Roth and Betula pubescens Ehrh. Seeds from several families (controlled crossings of known parent trees) of each species were used and Vis + NIR reflectance spectra were obtained from single seeds. Multivariate discriminant models were developed by Orthogonal Projections to Latent Structures – Discriminant Analysis (OPLS-DA). The OPLS-DA model fitted on Vis + NIR spectra recognized B. pubescens with 100% classification accuracy while the prediction accuracy of class membership for B. pendula was 99%. However, the discriminant models fitted on NIR spectra alone resulted in 100% classification accuracies for both species. Absorption bands accounted for distinguishing between birch species were attributed to differences in color and chemical composition, presumably polysaccharides, proteins and fatty acids, of the seeds. In conclusion, the results demonstrate the feasibility of NIR spectroscopy as taxonomic tool for classification of species that have morphological resemblance.

  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Box 49, SE-230 52 Alnarp, Sweden E-mail: mulualem.tigabu@slu.se (email)
  • Farhadi, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Box 49, SE-230 52 Alnarp, Sweden E-mail: mostafa.farhadi@gmail.com
  • Stener, The Forestry Research Institute of Sweden, Ekebo 2250, SE-268 90 Svalöv, Sweden E-mail: lars-goran.stener@skogforsk.se
  • Odén, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Box 49, SE-230 52 Alnarp, Sweden E-mail: per.christer.oden@slu.se
article id 9980, category Research article
Eino Levkoev, Lauri Mehtätalo, Katri Luostarinen, Pertti Pulkkinen, Anatoly Zhigunov, Heli Peltola. (2018). Development of height growth and frost hardiness for one-year-old Norway spruce seedlings in greenhouse conditions in response to elevated temperature and atmospheric CO2 concentration. Silva Fennica vol. 52 no. 3 article id 9980. https://doi.org/10.14214/sf.9980
Keywords: climate change; Picea abies; needles; tree growth; seedlings; cold acclimation
Highlights: Elevated temperature resulted in increased height growth, delayed onset and shortened duration of autumn frost hardiness development in Norway spruce seedlings; Elevated temperature increased variation between genotypes in height growth and frost hardiness development; Elevated atmospheric CO2 concentration had no effect on the development of height or autumn frost hardiness in Norway spruce seedlings.
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The mean temperature during the potential growing season (April–September) may increase by 1 °C by 2030, and by 4 °C, or even more, by 2100, accompanied by an increase in atmospheric CO2 concentrations of 536–807 ppm, compared to the current climate of 1981–2010, in which atmospheric CO2 is at about 350 ppm. This may affect both the growth and frost hardiness of boreal trees. In this work, we studied the responses of height and autumn frost hardiness development in 22 half-sib genotypes of one-year-old Norway spruce (Picea abies (L.) Karst.) seedlings to elevated temperatures and atmospheric CO2 concentration under greenhouse conditions. The three climate treatments used were: T+1 °C above ambient and ambient CO2; T+4 °C above ambient and ambient CO2; and T+4 °C above ambient and elevated CO2 (700 ppm). The height growth rate and final height were both higher under T+4 °C compared to T+1 °C. Temperature increase also delayed the onset, and shortened the duration, of autumn frost hardiness development. Elevated CO2 did not affect the development of height or frost hardiness, when compared to the results without CO2 elevation under the same temperature treatment. Higher temperatures resulted in greater variation in height and frost hardiness development among genotypes. Three genotypes with different genetic backgrounds showed superior height growth, regardless of climate treatment; however, none showed a superior development of autumn frost hardiness. In future studies, clonal or full-sib genetic material should be used to study the details of autumn frost hardiness development among different genotypes.

  • Levkoev, University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: eino.levkoev@uef.fi (email)
  • Mehtätalo, University of Eastern Finland, Faculty of Science and Forestry, School of Computing, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: lauri.mehtatalo@uef.fi
  • Luostarinen, University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: katri.luostarinen@uef.fi
  • Pulkkinen,  Natural Resources Institute Finland (Luke), Production systems, Haapastensyrjä Breeding Station, FI-16200 Läyliäinen, Finland E-mail: pertti.pulkkinen@luke.fi
  • Zhigunov, Saint-Petersburg State Forest Technical University, Forestry Faculty, RU-194021, Institutskiy per. 5, Saint-Petersburg, Russia E-mail: a.zhigunov@bk.ru
  • Peltola, University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: heli.peltola@uef.fi
article id 7772, category Research article
Curt Almqvist. (2018). Improving floral initiation in potted Picea abies by supplemental light treatment. Silva Fennica vol. 52 no. 2 article id 7772. https://doi.org/10.14214/sf.7772
Keywords: Norway spruce; seed production; flower stimulation; strobili initiation; indoor seed orchard
Highlights: Supplemental light treatment:
  • Increases the proportion of genotypes initiating reproductive buds.
  • Increases floral induction, especially of female floral buds.
  • Facilitates breeding programmes, and seed production of highly improved base material from new selections for vegetative production programmes, to be more efficient.
Abstract | Full text in HTML | Full text in PDF | Author Info

Light is an important environmental factor for all green plants. Its intensity, spectral composition and photoperiod can affect the regulatory pathways in plants that lead to floral initiation. In this report, results are presented from three experiments in which supplemental light with metal halide lamps (250 µmol m–2 s–1, 20 hours day–1, approx. 6 weeks) was tested as a complement to other flowering stimulation treatments (elevated temperature, treatment with gibberellin A4 and A 7 (GA4/7), restricted water supply) applied to potted Picea abies (L.) Karst. in the greenhouse. Flower stimulation in a greenhouse resulted in more floral initiation compared to flower stimulation outdoors. Supplemental light treatment increased floral initiation further, and to a larger extent in female than in male flowers. It also increased the proportion of trees and genotypes that induced reproductive buds. In a practical application of the supplemental light treatment to potted Picea abies breeding material, 90.6% of the clones produced either female or male flowers, or both. A subset of the same material kept outdoors, and thus subjected to natural light and temperatures, produced no flowers despite being treated with GA4/7 and receiving a restricted water supply. In conclusion, supplemental light treatment facilitates breeding programmes, and seed production of highly improved base material from new selections for vegetative production programmes, to be more efficient.

  • Almqvist, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden ORCID http://orcid.org/0000-0001-5739-4854 E-mail: curt.almqvist@skogforsk.se (email)
article id 7751, category Research article
Göran Nordlander, Euan G. Mason, Karin Hjelm, Henrik Nordenhem, Claes Hellqvist. (2017). Influence of climate and forest management on damage risk by the pine weevil Hylobius abietis in northern Sweden. Silva Fennica vol. 51 no. 5 article id 7751. https://doi.org/10.14214/sf.7751
Keywords: temperature sum; reforestation; soil scarification; clear-cut age; conifer seedling; damage prediction; warmer climate
Highlights: Analysis of survey data from 292 reforestation areas in northern Sweden show that the probability of pine weevil damage can be predicted with a standard error of 0.12; Three variables are important in the optimal model: proportion of seedlings in mineral soil, age of clear-cut, and temperature sum; Temperature sum in the model can be adjusted to reflect future climate scenarios.
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The pine weevil Hylobius abietis L. is an economically important pest insect that kills high proportions of conifer seedlings in reforestation areas. It is present in conifer forests all over Europe but weevil abundance and risk for damage varies considerably between areas. This study aimed to obtain a useful model for predicting damage risks by analyzing survey data from 292 regular forest plantations in northern Sweden. A model of pine weevil attack was constructed using various site characteristics, including both climatic factors and factors related to forest management activities. The optimal model was rather imprecise but showed that the risk of pine weevil attack can be predicted approximatively with three principal variables: 1) the proportion of seedlings expected to be planted in mineral soil rather than soil covered with duff and debris, 2) age of clear-cut at the time of planting, and 3) calculated temperature sum at the location. The model was constructed using long-run average temperature sums for epoch 2010, and so effects of climate change can be inferred from the model by adjustment to future epochs. Increased damage risks with a warmer climate are strongly indicated by the model. Effects of a warmer climate on the geographical distribution and abundance of the pine weevil are also discussed. The new tool to better estimate the risk of damage should provide a basis for foresters in their choice of countermeasures against pine weevil damage in northern Europe.

  • Nordlander, Swedish University of Agricultural Sciences (SLU), Department of Ecology, P.O. Box 7044, SE-750 07 Uppsala, Sweden E-mail: Goran.Nordlander@slu.se
  • Mason, University of Canterbury, School of Forestry, Private Bag 4800, Christchurch 8140, New Zealand; Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID http://orcid.org/0000-0001-9024-9106 E-mail: euan.mason@canterbury.ac.nz (email)
  • Hjelm, Skogforsk, The Forest Research Institute of Sweden, Ekebo 2250, SE-268 90 Svalöv, Sweden; Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: karin.hjelm@skogforsk.se
  • Nordenhem, Swedish University of Agricultural Sciences (SLU), Department of Ecology, P.O. Box 7044, SE-750 07 Uppsala, Sweden E-mail: h.nordenhem@telia.com
  • Hellqvist, Swedish University of Agricultural Sciences (SLU), Department of Ecology, P.O. Box 7044, SE-750 07 Uppsala, Sweden E-mail: Claes.Hellqvist@slu.se
article id 7731, category Research article
Anneli Viherä-Aarnio, Pirkko Velling. (2017). Growth, wood density and bark thickness of silver birch originating from the Baltic countries and Finland in two Finnish provenance trials. Silva Fennica vol. 51 no. 4 article id 7731. https://doi.org/10.14214/sf.7731
Keywords: Betula pendula; provenance; bark thickness; frost crack; seed transfer; wood basic density; wood discolouration
Highlights: Baltic origins of silver birch had significantly thicker bark than the Finnish ones; In terms of wood density, no consistent difference was detected between the Baltic and Finnish origins; Incidence of darkened core wood increased with increasing seed origin latitude; Frost cracks were most common in south Latvian origins grown in central Finland.
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Silver birch (Betula pendula Roth) seed origins from the Baltic countries and from Finland were compared in terms of growth, wood density, bark thickness and the incidence of darkened core wood, frost cracks and decay, and the effect of seed origin latitude was examined in two Finnish provenance trials. The material consisted of 21 stand and single tree origins ranging from latitudes 54° to 63°N from the Baltic countries and Finland. The trials, measured at the age of 22 years, were located at Tuusula (60°21´N), southern Finland and at Viitasaari (63°11´N), central Finland. The Baltic origins were superior to the Finnish ones in the southern trial regarding height, whereas in central Finland the Finnish origins grew better. There was no consistent difference between the Baltic and the Finnish group of origins in wood density. Bark thickness decreased with increasing seed origin latitude. The Baltic origins had significantly thicker bark than the Finnish origins. A moderate positive correlation was detected between the seed origin latitude and the incidence of darkened core wood in the southern trial, where the darkened core wood was more common in the Finnish origins than in the Baltic ones. The highest proportion of trees with frost cracks was detected in the south-western Latvian origins growing in central Finland. Seed transfers from the Baltic would have an increasing effect on the bark thickness of birch logs, but no or only minor effects on wood density. Based on our results, there is no reason to recommend the use of non-native Baltic seed origins in Finland instead of the native locally adapted seed sources.

  • Viherä-Aarnio, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 2, FI-00791 Helsinki, Finland E-mail: anneli.vihera-aarnio@luke.fi (email)
  • Velling, E-mail: pike.velling@phnet.fi
article id 5643, category Research article
Katarzyna A. Jadwiszczak, Stanisław Kłosowski, Iwona Zalewska, Agata Banaszek, Agnieszka Chrzanowska. (2017). Genetic diversity and sexual reproduction in relict populations of Betula nana. Silva Fennica vol. 51 no. 2 article id 5643. https://doi.org/10.14214/sf.5643
Keywords: flowering; AFLP; dwarf birch; meiotic recombination; seed germination
Highlights: Genetic diversity parameters and meiotic recombination frequencies in the relict populations were comparable to those from widespread localities; Contribution of seeds without ovule was very high; Fully developed seeds germinated better in central populations; Significant differences of groundwater parameters were observed between relict and central populations.
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In the present study, the impact of geographical isolation and habitat conditions on genetic diversity and sexual reproduction was tested in four relict populations of dwarf birch Betula nana L. in Poland and Belarus. Amplified fragment length polymorphism (AFLP) method revealed that the endangered central European stands were not genetically extirpated compared with the widespread localities from Finland and Russia, which can result from infrequent outcrossing events in long-living clonal populations. However, genetic clustering methods indicated significant differentiation of the Polish populations because of their small sizes and long-term geographical isolation. Considerable numbers of empty seeds were observed in both relict and central locations, although fully developed seeds germinated better in widespread populations. Analysis of groundwater chemical parameters indicated that two relict populations were significantly different from the remaining samples with respect to pH, electrical conductivity and concentrations of phosphorus ions, which can also influence the efficiency of sexual reproduction. In the light of results obtained it seems that endangered B. nana localities are relatively stable.

  • Jadwiszczak, Institute of Biology, University of Białystok, Ciołkowskiego 1J, 15-245 Białystok, Poland ORCID http://orcid.org/0000-0002-9345-8891 E-mail: jadwiszczak2010@gmail.com (email)
  • Kłosowski, Department of Environment Protection and Modelling, The Jan Kochanowski University, Świętokrzyska 15, 25-406 Kielce, Poland E-mail: stanislaw.klosowski@ujk.kielce.pl
  • Zalewska, Faculty of Pharmacy, Medical University of Białystok, Mickiewicza 2a, 15-222 Białystok, Poland E-mail: iwonazalewska1988@gmail.com
  • Banaszek, Institute of Biology, University of Białystok, Ciołkowskiego 1J, 15-245 Białystok, Poland E-mail: banaszek@uwb.edu.pl
  • Chrzanowska, Institute of Biology, University of Białystok, Ciołkowskiego 1J, 15-245 Białystok, Poland E-mail: maga.chrzanowska@gmail.com
article id 1475, category Research article
Jiaxi Wang, Haiqun Yu, Guolei Li, Feng Zhang. (2016). Growth and nutrient dynamics of transplanted Quercus variabilis seedlings as influenced by pre-hardening and fall fertilization. Silva Fennica vol. 50 no. 2 article id 1475. https://doi.org/10.14214/sf.1475
Keywords: nutrient loading; nutrient storage; nursery transplanting; seedling quality
Highlights: High pre-hardening fertilization favored seedling growth and nutrient storage at the rapid growth and hardening phases following transplantation. Overall, high fall fertilization was beneficial only at the hardening phase; The combination of 100 mg N seedling–1 during pre-hardening with 36 mg N seedling–1 during hardening was recommended for satisfactory transplanting performance for Quercus variabilis.
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Stored nutrient reserves are closely correlated with survival and growth of transplanted seedlings. Previous studies have proven that combining pre-hardening fertilization (PF) with fall fertilization (FF) built seedling nutrient reserves more effectively; however, their effect on transplanting performance is poorly documented. We investigated the independent and interacting effects of 2 levels of PF and 4 levels of FF on seedling growth, nutrient acquisition and accumulation during different growth phases 1 year after transplanting of Quercus variabilis Blume in a nursery. High PF benefited nutrient reserves and subsequent transplanted seedling growth and tissue nutrient storage at the end of the rapid growth and hardening phases. Fall fertilization with 36 mg N increased stem dry mass and tissue nutrient content at the end of the hardening phase. At the conclusion of establishment, PF and FF showed a significant interaction for N and K uptake from soil. At the end of the rapid growth and hardening phases, high PF consistently increased nutrient uptake. Enhanced N and K uptake occurred following application of 36 mg N of FF at the end of the hardening phase. Distinct roles for PF and FF on 3 phases of transplanted seedlings demonstrated the necessity to evaluate fertilization in terms of nutrient reserves and subsequent transplanting performance in consecutive phases. Combining 100 mg N seedling–1 during pre-hardening with 36 mg N seedling–1 during fall yielded ideal transplanting performance for Quercus variabilis seedlings.

  • Wang, Key Laboratory for Silviculture and Conservation, Ministry of Education; Beijing Laboratory of Urban and Rural Ecological Environment, Beijing Forestry University, 35 East Qinghua Road, Haidian District, Beijing 100083, China E-mail: wjx198979@163.com
  • Yu, Beijing Forestry Carbon Administration, room 201, No.1 Xiao Huang Zhuang Bei Jie, Dongcheng District, Beijing 100013, China E-mail: yuhq@bfdic.com
  • Li, Key Laboratory for Silviculture and Conservation, Ministry of Education; Beijing Laboratory of Urban and Rural Ecological Environment, Beijing Forestry University, 35 East Qinghua Road, Haidian District, Beijing 100083, China E-mail: glli226@163.com (email)
  • Zhang, Beijing Forestry Carbon Administration, room 201, No.1 Xiao Huang Zhuang Bei Jie, Dongcheng District, Beijing 100013, China E-mail: zhangf@bfdic.com
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 1340, category Research article
Mostafa Farhadi, Mulualem Tigabu, Per Christer Odén. (2015). Near Infrared Spectroscopy as non-destructive method for sorting viable, petrified and empty seeds of Larix sibirica. Silva Fennica vol. 49 no. 5 article id 1340. https://doi.org/10.14214/sf.1340
Keywords: larch; NIRS; OPLS; precision sowing; seed sorting; seed quality
Highlights: Near Infrared spectroscopy discriminates filled-viable, empty and petrified seeds of Larix sibirica with 98%, 82% and 87% accuracy, respectively based on spectral differences attributed to moisture and storage reserves; The classification accuracy reached 100% when sorting seeds into viable and non-viable class; The results demonstrate that NIR spectroscopy has great potential as non-destructive sorting technique to upgrade seed lot quality.
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Larix sibirica Ledeb. is one of the promising timber species for planting in the boreal ecosystem; but poor seed lot quality is the major hurdle for production of sufficient quantity of planting stocks. Here, we evaluated the potential of Near Infrared (NIR) Spectroscopy for sorting viable and non-viable seeds, as the conventional sorting technique is inefficient. NIR reflectance spectra were collected from single seeds, and discriminant models were developed with Orthogonal Projections to Latent Structure – Discriminant Analysis (OPLS-DA). The computed model predicted the class membership of filled-viable, empty and petrified seeds in the test set with 98%, 82% and 87% accuracy, respectively. When two-class OPLS-DA model was fitted to discriminate viable and non-viable (empty and petrified seeds combined), the predicted class membership of test set samples was 100% for both classes. The origins of spectral differences between non-viable (petrified and empty) and viable seeds were attributed to differences in seed moisture content and storage reserves. In conclusion, the result provides evidence that NIR spectroscopy is a powerful non-destructive method for sorting non-viable seeds of Larix sibirica; thus efforts should be made to develop on-line sorting system for large-scale seed handling.

  • Farhadi, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: mostafa.farhadi@slu.se
  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: mulualem.tigabu@slu.se (email)
  • Odén, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: per.oden@slu.se
article id 1334, category Research article
Abolfazl Daneshvar, Mulualem Tigabu, Asaddollah Karimidoost, Per Christer Oden. (2015). Single seed Near Infrared Spectroscopy discriminates viable and non-viable seeds of Juniperus polycarpos. Silva Fennica vol. 49 no. 5 article id 1334. https://doi.org/10.14214/sf.1334
Keywords: NIRS; OPLS; seed sorting; Iran; juniper; near infrared spectroscopy
Highlights: Near Infrared (NIR) Spectroscopy discriminates viable and non-viable (empty, insect-attacked and shriveled) seeds of J. polycarpos with 98% and 100% accuracy, respectively; The origins of spectral differences between non-viable and viable seeds were attributed to differences in seed coat chemical composition and storage reserves; The results demonstrate that NIR spectroscopy has great potential as seed sorting technology to ensure precision sowing.
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A large quantity of non-viable (empty, insect-attacked and shriveled) seeds of Juniperus polycarpos (K. Koch) is often encountered during seed collection, which should be removed from the seed lots to ensure precision sowing in the nursery or out in the field. The aims of this study were to evaluate different modelling approaches and to examine the sensitivity of the change in detection system (Silicon-detector in the shorter vis-a-vis InGsAs-detector in the longer NIR regions) for discriminating non-viable seeds from viable seeds by Near Infrared (NIR) spectroscopy. NIR reflectance spectra were collected from single seeds, and discriminant models were developed by Partial Least Squares – Discriminant Analysis (PLS-DA) and Orthogonal Projection to Latent Structures – Discriminant Analysis (OPLS-DA) using the entire or selected NIR regions. Both modelling approaches resulted in 98% and 100% classification accuracy for viable and non-viable seeds in the test set, respectively. However, OPLS-DA models were superb in terms of model parsimony and information quality. Modelling in the shorter and longer wavelength region also resulted in similar classification accuracy, suggesting that prediction of class membership is insensitive to change in the detection system. The origins of spectral differences between non-viable and viable seeds were attributed to differences in seed coat chemical composition, mainly terpenoids that were dominant in non-viable seeds and storage reserves in viable seeds. In conclusion, the results demonstrate that NIR spectroscopy has great potential as seed sorting technology to upgrade seed lot quality that ensures precision sowing.

  • Daneshvar, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53, Alnarp, Sweden; (permanent address) Department of Natural Resources, Gonbad Kavous University, Shahid Fallahi Street, P.O. Box 163, Gonbad, Iran E-mail: abolfazl.daneshvar@slu.se
  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53, Alnarp, Sweden E-mail: mulualem.tigabu@slu.se (email)
  • Karimidoost, Agriculture and Natural Resources Research Center of Golestan Province, Beheshti Ave. P.O. Box 4915677555, Gorgan, Iran E-mail: karimidoost@yahoo.com
  • Oden, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53, Alnarp, Sweden E-mail: per.oden@slu.se
article id 1243, category Research article
Curt Almqvist, Gunnar Jansson. (2015). Effects of pruning and stand density on cone and pollen production in an experimental Pinus sylvestris seed orchard. Silva Fennica vol. 49 no. 4 article id 1243. https://doi.org/10.14214/sf.1243
Keywords: spacing; seed orchard management; crown management; seed production
Highlights: Pollen production of Pinus sylvestris began at the same age for all studied stand density and pruning height combinations but increased more rapidly at higher densities; Treatments with dense spacing increased seed production earlier; Many combinations of stand density and target height gave comparable levels of seed production, yielding a wide range of viable management options.
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Seed orchards are the link between tree breeding and reforestation. This paper presents data on cone, seed and pollen production and seed quality gathered over 21 years in a Pinus sylvestris (L.) experimental seed orchard containing plots with 14 different combinations of stand density and targeted pruning height. The treatments’ stand densities ranged from 267 to 4000 stems ha-1, and the target graft heights ranged from 2 to 6 meters. Pollen production began at the same orchard age for all studied combinations of stand density and target height but the level of pollen production per hectare increased more rapidly in treatments with higher stand densities. In treatments with dense spacing, cone and seed production initially increased more rapidly than in treatments with wider spacing, thereby providing an earlier return on investment and a shorter seed production lag time. However, the levels of cone and seed production in such treatments over the entire study period were not appreciably different to those achieved in treatments with wider spacing and higher target height. The treatments did not differ substantially with respect to seed quality. These results show that comparable levels of seed production can be obtained with different combinations of stand density and target height, giving seed orchard owners and managers a wide range of viable management options.

  • Almqvist, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: curt.almqvist@skogforsk.se (email)
  • Jansson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: gunnar.jansson@skogforsk.se
article id 1056, category Research article
Katri Himanen, Markku Nygren. (2015). Seed soak-sorting prior to sowing affects the size and quality of 1.5-year-old containerized Picea abies seedlings. Silva Fennica vol. 49 no. 3 article id 1056. https://doi.org/10.14214/sf.1056
Keywords: Norway spruce; seed treatment; seed radiography; seedling emergence; seedling morphology
Highlights: After soak-sorting all sunken seeds (bottom fraction) were full and viable, whereas floating seeds contained larvae-filled and immature seed; Seedlings originating from the bottom fraction were greater in height and diameter than control seedlings or those originating from the floating seeds; The proportion of saleable seedlings was four percentage points higher in the bottom fraction than in the other seedlings.
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We studied the effect of soak-sorting Norway spruce (Picea abies (L.) H. Karst.) seeds on emergence, development and quality of container seedlings in two commercial seed lots. The seeds, separated by soaking into bottom and surface fractions, were sown in June, and the seedlings were grown during two growing seasons under typical Finnish nursery conditions. The first summer seedlings were grown in a greenhouse and outdoors for the second, full growing season. All sunken seeds were full and viable according to radiography, whereas the floating seeds contained 2% and 13% larvae-filled and 8% and 11% anatomically immature seeds, depending on the seed lot. Seedlings grown from the bottom fraction seed emerged 2.5–3.5 days earlier than seedlings of storage dry (i.e. control) seed. Height, diameter, and shoot and root dry mass of the seedlings were affected by soaking after both the first and second growing seasons. The largest seedlings originated from the bottom fraction. The proportion of saleable seedlings was four percentage points higher in the bottom fraction than in the other seedlings. The effects of soaking found in this study are more notable than as previously reported for Norway spruce seedlings. This suggests that soaking and soak-sorting may be most useful when the growing conditions are stressful, i.e. when seeds are sown in summer rather than 1-year-old seedling crops sown in spring under the climate conditions typical of Finland.

  • Himanen, Natural Resources Institute Finland (Luke), Green technology, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: katri.himanen@luke.fi (email)
  • Nygren, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: markku.nygren@luke.fi
article id 1266, category Research article
Edwyn K. Midmore, Shelagh A. McCartan, Richard L. Jinks, Christine M. Cahalan. (2015). Using thermal time models to predict germination of five provenances of silver birch (Betula pendula Roth) in southern England. Silva Fennica vol. 49 no. 2 article id 1266. https://doi.org/10.14214/sf.1266
Keywords: climate change; seed source; assisted migration; thermal time model
Highlights: Using cumulative germination data, thermal time models were developed for Betula pendula; Models indicated varying degrees of dormancy and pre-chill requirements among provenances; Thermal time parameters were used with climatic data to predict germination times under mild and cold winters in southern England; Predictions suggest that pre-chilled French seeds would germinate about six weeks later than the fastest germinating provenance.
Abstract | Full text in HTML | Full text in PDF | Author Info
Climate predictions indicate that growing conditions may become unfavourable for certain tree species in parts of Britain. Guidelines suggest some planting of seed sources from regions between 2° and 5° south of those currently used as part of a climate change adaptation strategy. However, there has been little research on the benefits and risks associated with the use of planting stock from more southerly seed sources. Seeds of five provenances of the ‘relatively’ dormant Betula pendula were germinated over a range of temperatures both with and without a pre-chill. Subsequently, a thermal time model was used to predict the impact of migrating these provenances to southern England. Results identified geographical differences in germination response; those from higher latitude were more sensitive to pre-chill.
  • Midmore, Forest Research Agency, Alice Holt, Surrey. Current: Dolwyddelan, Llandre, Ceredigion, Wales, SY24 5BZ E-mail: emidmore@gmail.com
  • McCartan, Forest Research, Alice Holt, Farnham, Surrey, GU10 4LH, UK E-mail: shelagh.mccartan@forestry.gsi.gov.uk (email)
  • Jinks, Forest Research, Alice Holt Lodge, Farnham, Surrey, GU10 4LH, UK E-mail: richard.jinks@forestry.gsi.gov.uk
  • Cahalan, Bangor University, School of Environment, Natural Resources and Geography, Bangor, Gwynedd, Wales, LL57 2UW E-mail: c.m.cahalan@bangor.ac.uk
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 1064, category Research article
Back Tomas Ersson, Urban Bergsten, Ola Lindroos. (2014). Reloading mechanized tree planting devices faster using a seedling tray carousel. Silva Fennica vol. 48 no. 2 article id 1064. https://doi.org/10.14214/sf.1064
Keywords: productivity; cost analysis; seedling feed; silviculture; time study; tree planting machine; containerized seedling
Highlights: Seedling reloading onto the Bracke Planter crane-mounted planting device was twice as fast with the MagMat tray-wise-loaded carousel as today’s seedling-wise-loaded carousel; Tray-wise reloading combined with deplugging seedlings from suitable cultivation trays has the potential to be an efficient and robust way to feed seedlings on any type of tree planting machine.
Abstract | Full text in HTML | Full text in PDF | Author Info
On Nordic clearcuts, today’s tree planting machines produce high-quality but costly regenerations. Much of this high cost is attributable to the planting machines’ low productivity. One promising way of raising productivity is to lessen the time spent manually reloading seedlings onto the carousels of crane-mounted planting devices. Using MagMat, a carousel test-rig designed by engineering students, we studied how much faster tray-wise seedling reloading is on the Bracke Planter compared to reloading with today’s seedling-wise-loaded carousel. The MagMat test-rig held eight Hiko cultivation trays from which seedlings were deplugged individually and dropped into the planting tube. The time study confirmed that seedling reloading was on average twice as fast with MagMat compared to today’s seedling carousel, thereby increasing assumed planting machine productivity by 8–9% depending on the planting device used. MagMat’s cost-efficiency was analysed to be particularly reliant on its added investment cost, mechanical availability and how quickly trays can be switched automatically. Nevertheless, MagMat’s field performance illustrated the overall potential of tray-wise loading compared to piecewise seedling loading for increasing the productivity of crane-mounted planting devices. Also, deplugging proved to be a reliable method of extracting seedlings from the rigid, copper-painted Hiko cultivation trays even when performed at the excavator’s boom-tip during mounding work. We conclude that, rather than piecewise seedling loading, tray-wise loading combined with deplugging seedlings from suitable cultivation trays is a reliable and much more time-efficient method to feed seedlings on probably any type of tree planting machine.
  • Ersson, Department of Forest Biomaterials and Technology, SLU, SE-90183 Umeå, Sweden E-mail: back.tomas.ersson@slu.se (email)
  • Bergsten, Department of Forest Biomaterials and Technology, SLU, SE-90183 Umeå, Sweden E-mail: urban.bergsten@slu.se
  • Lindroos, Department of Forest Biomaterials and Technology, SLU, SE-90183 Umeå, Sweden E-mail: ola.lindroos@slu.se
article id 952, category Research article
Lauri Korhonen, Inka Pippuri, Petteri Packalén, Ville Heikkinen, Matti Maltamo, Juho Heikkilä. (2013). Detection of the need for seedling stand tending using high-resolution remote sensing data. Silva Fennica vol. 47 no. 2 article id 952. https://doi.org/10.14214/sf.952
Keywords: forest management; airborne laser scanning; logistic regression; seedling stand; tending; support vector machine
Abstract | Full text in HTML | Full text in PDF | Author Info
Seedling stands are problematic in airborne laser scanning (ALS) based stand level forest management inventories, as the stem density and species proportions are difficult to estimate accurately using only remotely sensed data. Thus the seedling stands must still be checked in the field, which results in an increase in costs. In this study we tested an approach where ALS data and aerial images are used to directly classify the seedling stands into two categories: those that involve tending within the next five years and those which involve no tending. Standard ALS-based height and density features, together with texture and spectral features calculated from aerial images, were used as inputs to two classifiers: logistic regression and the support vector machine (SVM). The classifiers were trained using 208 seedling plots whose tending need was estimated by a local forestry expert. The classification was validated on 68 separate seedling stands. In the training data, the logistic model’s kappa coefficient was 0.55 and overall accuracy (OA) 77%. The SVM did slightly better with a kappa = 0.71 and an OA = 86%. In the stand level validation data, the performance decreased for both the logistic model (kappa = 0.38, OA = 71%) and the SVM (kappa = 0.37, OA = 72%). Thus our approach cannot totally replace the field checks. However, in considering the stands where the logistic model predictions had high reliability, the number of misclassifications reduced drastically. The SVM however, was not as good at recognizing reliable cases.
  • Korhonen, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: lauri.korhonen@uef.fi (email)
  • Pippuri, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: inka.pippuri@uef.fi
  • Packalén, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: petteri.packalen@uef.fi
  • Heikkinen, School of Computing, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: ville.heikkinen@uef.fi
  • Maltamo, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: matti.maltamo@uef.fi
  • Heikkilä, Finnish Forest Centre, Public Services, Maistraatinportti 4 A, FI-00240 Helsinki, Finland E-mail: juho.heikkila@metsakeskus.fi
article id 932, category Research article
Jun Wang, Le Shi, Shaoyu Song, Ju Tian, Xiangyang Kang. (2013). Tetraploid production through zygotic chromosome doubling in Populus. Silva Fennica vol. 47 no. 2 article id 932. https://doi.org/10.14214/sf.932
Keywords: Populus; colchicine; high temperature; seed hair; tetraploid induction; zygote
Abstract | Full text in HTML | Full text in PDF | Author Info
The most direct approach in breeding triploid Populus is crossing allotetraploids with diploids. However, the lack of allotetraploid Populus restricts application of this approach. In this investigation, zygotic chromosome doubling was induced with colchicine and high temperatures to produce ((Populus pseudo-simonii × P. nigra ‘Zheyin3#’) × (P. × beijingensis)) allotetraploids. We screened 6 and 25 tetraploid individual offspring from the colchicine and high-temperature treatments respectively, indicating that both colchicine and high temperature are effective for tetraploid production by zygotic chromosome doubling of Populus. Developmental characteristics of seed hairs in the ovaries were temporally associated with zygotic development, which was used to successfully guide the colchicine and high-temperature treatments. During certain stages of hair development, the efficiency of tetraploid production was significantly high. However, efficiency of production was not significantly influenced by other factors, i.e. colchicine concentration, temperature or duration of high-temperature treatment. Size and frequency of leaf stomata between tetraploid and diploid plants were significantly different, suggesting that this character can be altered via genomic increase in material. The allotetraploids produced in this investigation, having different genotypes, provide important parental germplasms for further triploid breeding.
  • Wang, National Engineering Laboratory for Tree Breeding; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education; College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, P.R. China E-mail: wangjun@bjfu.edu.cn (email)
  • Shi, National Engineering Laboratory for Tree Breeding; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education; College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, P.R. China E-mail: 7320932@qq.com
  • Song, National Engineering Laboratory for Tree Breeding; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education; College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, P.R. China E-mail: angela-song@foxmail.com
  • Tian, National Engineering Laboratory for Tree Breeding; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education; College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, P.R. China E-mail: 1215813245@qq.com
  • Kang, National Engineering Laboratory for Tree Breeding; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education; College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, P.R. China E-mail: kangxy@bjfu.edu.cn
article id 903, category Research article
Mikko Hyppönen, Ville Hallikainen, Juhani Niemelä, Pasi Rautio. (2013). The contradictory role of understory vegetation on the success of Scots pine regeneration. Silva Fennica vol. 47 no. 1 article id 903. https://doi.org/10.14214/sf.903
Keywords: site preparation; seedling establishment; seedling mortality; field- and ground-layer vegetation; modelling approach; initial growth; prescribed burning
Abstract | Full text in HTML | Full text in PDF | Author Info
In North-East Finland, severe problems have been encountered in the natural regeneration of Scots pine (Pinus sylvestris L.) on sites where regeneration through site preparation usually is quite successful. We hypothesized that in that area understory vegetation, especially heather (Calluna vulgaris), crowberry (Empetrum hermaphroditum), mosses and lichens, could play a key role in this pattern. We found that in general, ground- and field-layer vegetation tends to be in a negative relationship with the establishment, growth and survival of pine seedlings. Some positive relationships were also observed. Lingonberry (Vaccinium vitis-idea) tended to improve seedling height growth. Heather, instead, seemed to have a contradictory role. It was positively related to seedling establishment but negatively to seedling growth. This dual role raises further questions about the primary reasons for the regeneration problems in North-East Finland. All in all, our results suggest that conventional methods of forest regeneration in these kinds of areas are not always effective enough and additional measures are needed. These might include severe prescribed burning along with site preparation in order to decrease the impact of the dominant ground- and field-layer vegetation on the success of Scots pine regeneration.
  • Hyppönen, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: mikko.hypponen@metla.fi (email)
  • Hallikainen, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: ville.hallikainen@metla.fi
  • Niemelä, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: jn@nn.fi
  • Rautio, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: pasi.rautio@metla.fi
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 65, category Research article
Kristóf Kelemen, Barbara Mihók, László Gálhidy, Tibor Standovár. (2012). Dynamic response of herbaceous vegetation to gap opening in a Central European beech stand. Silva Fennica vol. 46 no. 1 article id 65. https://doi.org/10.14214/sf.65
Keywords: continuous cover forestry; dispersal; gap colonization; herbs; seed bank type; species richness
Abstract | View details | Full text in PDF | Author Info
Herbaceous ground vegetation in artificially-created gaps was studied in a managed beech (Fagus sylvatica L.) forest over a period of eight years in Northern Hungary, Central Europe. These gaps were being used as an alternative to the regular shelterwood system to create uneven-aged stands. The effects of gap size (15 and 40 m diameter) and canopy openness on herbaceous species colonization and persistence were assessed in a systematic grid of 5 5 m. Overall, herbaceous cover was low before gap creation, increased soon afterwards, and continued to rise over time. The number of herb species increased in the gaps and, to a lesser extent, in adjacent areas under the remaining tree canopy. Colonization of gaps was rapid and there was substantial turnover of species i.e. various species disappeared from the gaps over time whilst others colonized. Species with both long-term persistent seed banks and long distance dispersal abilities were the most successful types colonizing gaps. Six species occurred preferentially in large gaps, while only one species was found to prefer small gaps. Species present before gap creation survived in both gap sizes. Smaller gaps with a diameter of half the height of canopy trees also tended to remain free of common weed species, whereas large cover of Rubus fruticosus L. and Calamagrostis epigejos (L.) Roth could hamper natural regeneration in larger gaps. For the successful regeneration of beech we recommend the use of small gaps complemented by few large gaps.
  • Kelemen, Loránd Eötvös University, Institute of Biology, Department of Plant Systematics, Ecology and Theoretical Biology, Budapest, Hungary E-mail: kk@nn.hu
  • Mihók, Loránd Eötvös University, Institute of Biology, Department of Plant Systematics, Ecology and Theoretical Biology, Budapest, Hungary E-mail: bm@nn.hu
  • Gálhidy, Loránd Eötvös University, Institute of Biology, Department of Plant Systematics, Ecology and Theoretical Biology, Budapest, Hungary E-mail: lg@nn.hu
  • Standovár, Institute of Biology, Department of Plant Systematics, Ecology and Theoretical Biology, Budapest, Hungary E-mail: standy@ludens.elte.hu (email)
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 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 108, category Research article
Back Tomas Ersson, Urban Bergsten, Ola Lindroos. (2011). The cost-efficiency of seedling packaging specifically designed for tree planting machines. Silva Fennica vol. 45 no. 3 article id 108. https://doi.org/10.14214/sf.108
Keywords: logistics; mechanized planting; containerized seedlings; seedling transport; cost analysis; seedling feed; nursery technology
Abstract | View details | Full text in PDF | Author Info
Today’s crane-mounted planting heads plant seedlings with biologically similar or better results than operational manual planting. However, the total cost of mechanized tree planting in southern Sweden must decrease at least 25% to compete economically with manual planting. Although seedlings packed in machine-specific packaging increase the productivity of planting machines by reducing seedling reloading time, they also increase logistics and investment costs. In this study, we analyzed the total cost of outplanting seedlings with an excavator-mounted Bracke Planter and seedlings packed according to four different concepts: cultivation trays, cardboard boxes, band-mounted seedlings in cardboard boxes and linked pots in container modules. The total cost per planted seedling was calculated for each packaging system as the sum of all costs from nursery to the recovery of empty packaging. The results showed that today’s system of transporting seedlings in cultivation trays is the most cost-efficient of the four alternatives. Machine-specific seedling packaging was 16–23% costlier per planted seedling than cultivation trays when trucking distances were 100 km. Sensitivity analyses indicated that machine-specific seedling packaging increased in cost-efficiency relative to cultivation trays primarily when more planting machines were contracted, but also as planting machine fixed costs and productivity increased. Moreover, the relative cost-efficiency of band-mounted seedlings, but not seedlings in container modules, increased with increasing trucking distance. Thus, we show that investments in machine-specific seedling packaging for today’s planting machines are justified only when the fixed costs, productivity and number of contracted planting machines increase substantially.
  • Ersson, Swedish University of Agricultural Sciences, Department of Forest Resource Management, SE-90183 Umeå, Sweden E-mail: back.tomas.ersson@slu.se (email)
  • Bergsten, Swedish University of Agricultural Sciences, Department of Forest Resource Management, SE-90183 Umeå, Sweden E-mail: ub@nn.se
  • Lindroos, Swedish University of Agricultural Sciences, Department of Forest Resource Management, SE-90183 Umeå, Sweden E-mail: ol@nn.se
article id 125, category Research article
Juho Rantala, Tiina Laine. (2010). Productivity of the M-Planter tree-planting device in practice. Silva Fennica vol. 44 no. 5 article id 125. https://doi.org/10.14214/sf.125
Keywords: silviculture; cost-efficiency; mechanisation; planting; seedling; technology
Abstract | View details | Full text in PDF | Author Info
Need to mechanise tree-planting work have recently increased for many reasons. The newest planting and soil scarification device performing work in Nordic forests is the Finnish M-Planter. This study aims to clarify M-Planter’s productivity in practice and show how various factors affect it. The follow-up data set covers 607 work shifts, of 13 operators with, in total, five M-Planters. The average productivity figures for the operators were 143 and 169 seedlings per effective working hour during the first and second planting season, respectively. Overall, the measured average productivity was 34.2% lower than that observed in an earlier work study of the M-Planter based on an experimental study design. On average, the operators learned to use the combination of the M-Planter and a base machine more efficiently while their experience in using it increased during the follow-up. Increasing number of stones and stumps as well as a thicker humus layer decreased productivity of the M-Planter. The study concludes that utilisation of the full productivity potential of the M-Planter requires not only good operators but also development of the whole planting service supply chain.
  • Rantala, Finnish Forest Research Institute, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: juho.rantala@metla.fi (email)
  • Laine, Finnish Forest Research Institute, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: tl@nn.fi
article id 120, category Research article
Antti J. Lukkarinen, Seppo Ruotsalainen, Teijo Nikkanen, Heli Peltola. (2010). Survival, height growth and damages of Siberian (Larix sibirica Ledeb.) and Dahurian (Larix gmelinii Rupr.) larch provenances in field trials located in southern and northern Finland. Silva Fennica vol. 44 no. 5 article id 120. https://doi.org/10.14214/sf.120
Keywords: height growth; survival; larch; Larix; provenance; seedling damage
Abstract | View details | Full text in PDF | Author Info
The aim of this study was to analyse differences in the survival and height growth of, as well as damages to Siberian (Larix sibirica Ledeb.) and Dahurian (Larix gmelinii Rupr.) larch provenances over four growing seasons in field trials established in 2006 in southern (Punkaharju) and northern Finland (Kivalo). In this context, the study also investigated if the geographical and climatic conditions of the origin of the provenance could explain the differences between the provenances. The study material consisted of 20 Russian Siberian and Dahurian larch provenances and five seed sources from Finland (4) and Russia (1) as comparison lots. It was found that the Finnish seed sources of Siberian larch survived well in both the Kivalo and Punkaharju trials. Five northern latitude Russian provenances, of which one was Dahurian and the remainder were Siberian larches, had the highest survival in Kivalo. However, the differences observed in survival between provenances were only significant (p < 0.05) in Kivalo. Regardless of the trial, the differences, however, in height growth were significant and large between provenances. The southern Dahurian larches had a superior height growth in Punkaharju. The northern Dahurian larch provenance from Magadan (59°50′N, 150°40′E) had the largest height growth in Kivalo, among some northern Siberian larches. Damages were diverse, though Dahurian larches had less mammal damage than the Siberian larches. In general, the differences between provenances were not significant. Latitude and altitude best explained the differences between provenances, but also mean temperature, temperature sum and continentality index affected them (p < 0.05).
  • Lukkarinen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: antti.lukkarinen@pp.inet.fi (email)
  • Ruotsalainen, Finnish Forest Research Institute, FI-58450 Punkaharju, Finland E-mail: sn@nn.fi
  • Nikkanen, Finnish Forest Research Institute, FI-58450 Punkaharju, Finland E-mail: tn@nn.fi
  • Peltola, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hp@nn.fi
article id 131, category Research article
Timo Pukkala, Tatu Hokkanen, Teijo Nikkanen. (2010). Prediction models for the annual seed crop of Norway spruce and Scots pine in Finland. Silva Fennica vol. 44 no. 4 article id 131. https://doi.org/10.14214/sf.131
Keywords: flowering; cone crops; seed years; mixed model
Abstract | View details | Full text in PDF | Author Info
Many studies indicate that the flowering abundance of boreal trees strongly correlates with the weather conditions of the previous summer. This study developed prediction models for the seed crops of Norway spruce and Scots pine using weather variables one and two years prior to flowering year as predictors. Weather data, systematically recorded at many weather stations, were obtained from the Finnish Meteorological Institute. Seed crop monitoring data came from 22 spruce stands and 44 pine stands. In every stand, seed crop has been monitored for many years, the longest continuous period being 45 years. Monthly mean temperatures, monthly rainfalls, and periodical temperature sums were used as predictors in the seed crop models. Generally, both tree species flowered abundantly one year after a warm summer and two years after a cool summer. While the models only explained about 45% of the variation in the annual seed crop, they accurately predicted good and bad seed years: when the models predicted good seed crops the likelihood to have at least a medium seed crop was very high and when the models predicted small seed crops, the likelihood to obtain medium or good seed crop was very low. Therefore, the models reliably predict if a particular year will be a good seed year or a poor seed year. These predictions can be used in forestry practice for proper timing of natural regeneration activities, and when activities in seed orchards are planned.
  • Pukkala, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: timo.pukkala@uef.fi (email)
  • Hokkanen, Finnish Forest Research Institute, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: th@nn.fi
  • Nikkanen, Finnish Forest Research Institute, Finlandiantie 18, FI-58450 Punkaharju, Finland E-mail: tn@nn.fi
article id 209, category Research article
Jaana Luoranen, Kyösti Konttinen, Risto Rikala. (2009). Frost hardening and risk of a second flush in Norway spruce seedlings after an early-season short-day treatment. Silva Fennica vol. 43 no. 2 article id 209. https://doi.org/10.14214/sf.209
Keywords: frost hardiness; Picea abies; bud formation; container seedlings; height growth cessation; second flush
Abstract | View details | Full text in PDF | Author Info
There have been years in Finland when container seedlings of Norway spruce (Picea abies (L.) Karsten) planted in the summer have been damaged by early-autumn frosts. For August and September plantings, the seedlings can be hardened by means of short-day (SD) treatment, but little information is available about its usability for earlier plantings. We studied the effects of early-season SD treatment on the frost hardiness and risk of a second flush of Norway spruce seedlings. In three successive years, second-year seedlings were grown in a greenhouse or outdoors in the spring and early summer and then subjected to two or three-week SD treatment beginning on the second, third, or fourth week of June. We monitored the height growth cessation, bud formation, and frost hardiness of the seedlings in the nursery. All SD treatments made the height growth cease, but the risk of a second flush increased if the temperature sum was less than 300 d.d. before the beginning of the SD treatment or more than 450 d.d. between the end of the treatment and mid-August. Clearly, then, SD treatment reduced the risk of a second flush in seedlings that had been grown in a greenhouse in the spring. Early-season SD treatment increased the frost hardiness of both needles and stems for late July to early September in comparison with untreated seedlings. Later in the autumn, however, the differences disappeared. Before recommending the use of early-season SD-treated seedlings for summer planting, the method has to be tested in practical field conditions.
  • Luoranen, The Finnish Forest Research Institute, Suonenjoki Research Unit, FI-77600 Suonenjoki, Finland E-mail: jaana.luoranen@metla.fi (email)
  • Konttinen, The Finnish Forest Research Institute, Suonenjoki Research Unit, FI-77600 Suonenjoki, Finland E-mail: kk@nn.fi
  • Rikala, The Finnish Forest Research Institute, Suonenjoki Research Unit, FI-77600 Suonenjoki, Finland E-mail: rr@nn.fi
article id 234, category Research article
Enni Flykt, Sari Timonen, Taina Pennanen. (2008). Variation of ectomycorrhizal colonisation in Norway spruce seedlings in Finnish forest nurseries. Silva Fennica vol. 42 no. 4 article id 234. https://doi.org/10.14214/sf.234
Keywords: Picea abies; nursery; containerised seedlings; ectomycorrhiza; fungal diversity
Abstract | View details | Full text in PDF | Author Info
Ectomycorrhizal (ECM) colonisation patterns and seedling growth of containerised spruce seedlings were studied in five typical Finnish forest nurseries by morphotyping and molecular characterisation. ECM colonisation degree of 1-year-old spruce seedlings was below 20% in all studied Finnish forest nurseries. In 2-year-old spruce seedlings the ECM colonisation degree was ca. 50–60% in three of the nurseries, but negligible in others. The ECM fungal species richness varied from 0.1 to 3.8 types per seedling. Altogether seven ECM morphotypes were distinguished. The clearest factors associated with ECM colonisation patterns were nitrogen and phosphorus fertilisation. Particularly fertilisation in the early stage of seedling development appeared to diminish the degree of colonisation and species richness of ECM fungi. Root/shoot ratio was positively correlated with high colonisation degree and species richness of ECM fungi. Higher fertilisation inputs in these overall fertilisation levels did not increase the size of the seedlings. According to these results moderate fertilisation levels particularly in the beginning of seedling cultivation are critical for generating higher root/shoot ratios and sufficient ECM colonisation degree of the roots.
  • Flykt, University of Helsinki, Department of Applied Chemistry and Microbiology, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: ef@nn.fi (email)
  • Timonen, University of Helsinki, Department of Applied Chemistry and Microbiology, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: st@nn.fi
  • Pennanen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: tp@nn.fi
article id 242, category Research article
Jyrki Hytönen, Paula Jylhä. (2008). Fifteen-year response of weed control intensity and seedling type on Norway spruce survival and growth on arable land. Silva Fennica vol. 42 no. 3 article id 242. https://doi.org/10.14214/sf.242
Keywords: Norway spruce; afforestation; frost damage; seedling size; seedling type; vegetation control
Abstract | View details | Full text in PDF | Author Info
The effects of seedling type (2-year-old container seedlings vs. 4-year-old bare-rooted seedlings) and post-planting vegetation control intensity on the growth and survival of Norway spruce (Picea abies (L.) Karst.) seedlings were compared based on 15-year data from a field experiment established on arable land. Vegetation control treatments with terbuthylazine and glyphosate were carried out 1–3 times on successive years, either as overall or spot applications. The highest stand volumes were obtained with the combination of large bare-rooted seedlings and effective vegetation control. Volume of bare-rooted seedlings was greater than that of container seedlings in all treatments (e.g. on the control plots 9.5 m3/ha vs. 4.1 m3/ha). The best results were obtained with the most intensive weed control treatments (spot treatment repeated twice and overall application repeated three times). These treatments increased both bare-rooted and containerised seedlings’ survival by 33–40% units and their height, breast height diameter, and volume by 45–49%, 17–47%, and 249–279%, respectively. In terms of survival, the container seedlings, in due part to their smaller size, benefited from vegetation control more than the bare-rooted seedlings. Successive early summer frosts damaged the seedlings and significantly retarded their growth. The frequency of frost damage was not affected by vegetation control nor was it attributed to seedling type.
  • Hytönen, Finnish Forest Research Institute, Kannus Research Unit, P.O. Box 44, FI-69101, Kannus, Finland E-mail: jyrki.hytonen@metla.fi (email)
  • Jylhä, Finnish Forest Research Institute, Kannus Research Unit, P.O. Box 44, FI-69101, Kannus, Finland E-mail: pj@nn.fi
article id 298, category Research article
Ulfstand Wennström, Urban Bergsten, Jan-Erik Nilsson. (2007). Seedling establishment and growth after direct seeding with Pinus sylvestris: effects of seed type, seed origin, and seeding year. Silva Fennica vol. 41 no. 2 article id 298. https://doi.org/10.14214/sf.298
Keywords: Scots pine; direct seeding; orchard seed; stand seed
Abstract | View details | Full text in PDF | Author Info
The early effects of seed type, seed origin, and seeding year on seedling emergence, survival, and growth after one to four years was quantified and examined. Two experimental series of Scots pine located at 61°N and 64°N and six orchard seed lots and six stand seed lots of adequate geographical origins in each series were used. Both series were replicated at five sites for up to five years. On average, orchard seed lots had 16% and 12% higher seedling emergence, in relation to sown germinable seeds, than stand seed lots in the northern and southern series. The survival from year 1 to year 4 was also higher for orchard seedlings than for stand seedlings; there was a 77% and 72% survival rate in the northern series and a 58% and 49% survival rate in the southern series for orchard and stand seedlings respectively. On average, after four years orchard seedlings were 26% taller in the northern series and 13% taller in the southern series. The gain in height growth for the orchard seeds was positive at all seeding years, at all sites, and at all seedling ages. If survival was calculated to the height of a four-year-old seedling, the survival of orchard seedlings increased by 3% in the northern and 1% in the southern series as the result of the higher growth of orchard seedlings. Using orchard seeds resulted in 6 percent units higher growth gain when the clear cuts were regenerated with direct seeding than with plants using the same seed material. Changes in the ranking of seed lots and seed types at different sites and seeding years for seedling emergence is an effect of external factors such as grazing and foraging that cannot be related directly to the tested factors.
  • Wennström, Skogforsk, Box 3, SE-918 21 Sävar, Sweden E-mail: ulfstand.wennstrom@skogforsk.se (email)
  • Bergsten, SLU, Dept. of Forest Ecology and Management, SE-901 83 Umeå, Sweden & SLU, Vindeln Experimental Forest, SE-922 91 Vindeln, Sweden E-mail: ub@nn.se
  • Nilsson, SLU, Dept. of Forest Genetics and Plant Physiology E-mail: jen@nn.se
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 305, category Research article
Anna-Maria Veijalainen, Marja-Liisa Juntunen, Arja Lilja, Helvi Heinonen-Tanski, Leo Tervo. (2007). Forest nursery waste composting in windrows with or without horse manure or urea – the composting process and nutrient leaching. Silva Fennica vol. 41 no. 1 article id 305. https://doi.org/10.14214/sf.305
Keywords: microbial hygiene; lignocellulose; nutrients; organic matter decomposition; temperature; tree seedling waste; waste management
Abstract | View details | Full text in PDF | Author Info
In order to find the best management practices for forest nursery waste composting, organic waste was composted without or with horse manure or urea in six windrows for two years. The windrows were built in four consecutive years during 1999–2002. In 1999, no extra-nutrients were added to the windrow (N99). In 2000, urea fertilizer was used as a nitrogen source (U00). Despite this, the process did not function properly. In 2001, two windrows were built, one (H01) with and the other (N01) without horse manure. Horse manure slightly accelerated the heating process. Consequently, two windrows with more horse manure were built in 2002. One was aerated passively (H02) as earlier windrows, and the other was aerated forcedly (HA02). Horse manure and forced aeration were needed to keep the temperature above 55°C for long enough to ensure microbial hygiene of the material. The degradation of cellulose was greater during the curing stage. Nutrient leaching was low, although the additives increased leaching in conjunction with the inefficient process. The results showed that forest nursery waste alone is ineffective at raising the temperature of the compost, and degrades slowly due to its low nutrient and easily available carbon content. The best management practice for forest nursery waste composting is to use horse manure and aeration to ensure the heating process. Environmental contamination can be avoided by collecting the leachates. Further research is needed to evaluate the usability of the compost.
  • Veijalainen, Finnish Forest Research Institute, FI-77600 Suonenjoki, Finland E-mail: amv@nn.fi (email)
  • Juntunen, Finnish Forest Research Institute, FI-77600 Suonenjoki, Finland E-mail: mlj@nn.fi
  • Lilja, Finnish Forest Research Institute, PO Box 18, FI-01301 Vantaa, Finland E-mail: al@nn.fi
  • Heinonen-Tanski, Univ. of Kuopio, Dept. of Environm. Sc., PO Box 1627, FI-70211 Kuopio, Finland E-mail: hht@nn.fi
  • Tervo, Finnish Forest Research Institute, FI-77600 Suonenjoki, Finland E-mail: lt@nn.fi
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 404, category Research article
William L. Mason, Colin Edwards, Sophie E. Hale. (2004). Survival and early seedling growth of conifers with different shade tolerance in a Sitka spruce spacing trial and relationship to understorey light climate. Silva Fennica vol. 38 no. 4 article id 404. https://doi.org/10.14214/sf.404
Keywords: seedling growth; light regime; stand density; irregular silviculture
Abstract | View details | Full text in PDF | Author Info
Alternative silvicultural systems to clearfelling are being adopted in Great Britain as a means of increasing the species and structural diversity of conifer plantation forests. One area where knowledge is lacking is the critical level of below-canopy light for survival and growth of young seedlings. This was investigated by planting seedlings of European larch Larix decidua (Mill.), Scots pine Pinus sylvestris L., Sitka spruce Picea sitchensis (Bong.(Carr.)), Douglas fir Pseudotsuga menziesii (Mirb.(Franco.)), and western hemlock Tsuga heterophylla (Raf. (Sarg.)) in a Sitka spruce plantation thinned to 3 different spacings. The incident light intensity beneath the canopy ranged from about 2 to over 60 per cent of full light. Planting in an adjoining open area provided an indication of growth under full light. Growth and survival of these seedlings were followed for 4 growing seasons. The highest seedling survival was found under the widest spacing and declined with closer spacing and lower light intensity. Only Douglas fir and western hemlock seedlings survived at the closest spacing, and in low percentages. The tallest seedlings of each species were found in the open grown conditions but survival was variable due to increased weed competition. Species-specific growth responses showed little difference under high light conditions but performance at low light was generally consistent with shade tolerance rankings in the literature except that Sitka spruce shade tolerance was slightly lower than expected. Minimum light requirements for these species increased from 10 to 30 per cent of full light with decreasing shade tolerance. Other studies of incident light in Sitka spruce plantations indicated that target basal areas in the range 25–30 m2 ha–1 are required if these light conditions are to be met, which suggests an irregular shelterwood system with frequent interventions should be favoured.
  • Mason, Forest Research, Northern Research Station, Roslin, Midlothian, Scotland, UK, EH25 9SY E-mail: bill.mason@forestry.gsi.gov.uk (email)
  • Edwards, Forest Research, Northern Research Station, Roslin, Midlothian, Scotland, UK, EH25 9SY E-mail: ce@nn.uk
  • Hale, Forest Research, Northern Research Station, Roslin, Midlothian, Scotland, UK, EH25 9SY E-mail: seh@nn.uk
article id 429, category Research article
Juho Rantala. (2004). Optimizing the supply chain strategy of a multi-unit Finnish nursery company. Silva Fennica vol. 38 no. 2 article id 429. https://doi.org/10.14214/sf.429
Keywords: economies of scale; supply chain management; optimization; mixed integer programming; seedling production
Abstract | View details | Full text in PDF | Author Info
This paper introduces a capacitated mixed integer programming (CMIP) model for solving an integrated production-distribution system design problem (PDSDP) in the seedling supply chain management (SCM) of a multi-unit Finnish nursery company. The model was originally developed from a strategic perspective in which a company desires to evaluate the expansion or closure of its facilities. Nevertheless, the model is also used for solving operational and tactical level problems by applying applicable constraints. The data were collected from the company studied. The results proved that economies of scale could be exploited in seedling production more than the company does today; Compared to the company’s current supply chain strategy with 5 nursery units producing seedlings, when other supply chain strategies were applied the number of nursery units decreased by 2–4 units, and cost savings in the supply chain varied from 11.3% to 21.3%.
  • Rantala, Finnish Forest Research Institute, Suonenjoki Research Station, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: juho.rantala@metla.fi (email)
article id 427, category Research article
Scott A. Weyenberg, Lee E. Frelich, Peter B. Reich. (2004). Logging versus fire: how does disturbance type influence the abundance of Pinus strobus regeneration? Silva Fennica vol. 38 no. 2 article id 427. https://doi.org/10.14214/sf.427
Keywords: disturbance refugia; interspecific competition; Minnesota; seedling dispersion; seed source; white pine
Abstract | View details | Full text in PDF | Author Info
Eastern white pine (Pinus strobus) has decreased in abundance over the past century throughout the Great Lakes Region of North America, but the relative constraints placed on recruitment under contrasting disturbance regimes are not well understood. The objectives of this study were to determine the extent to which white pine could invade areas recently disturbed by fire or logging (within 10–28 years), and assess the relative limitations placed on recruitment by seed supply, microsite habitat, and competition. We compared white pine regeneration on 61 sites disturbed by fire or logging that were adjacent to intact mature stands that provided a seed source. White pine seedling and sapling densities declined with increasing distance from a seed source, and the rate of decrease was determined by the interaction between seed supply and variation in number and quality of safe sites. For a given combination of seed source and site, white pine seedlings were three times more abundant on burned than logged sites. White pine seedlings grew into the sapling size class more often on burned than logged sites due to lower shrub cover on burned sites. At 25 years after disturbance, regeneration densities of white pine sufficient to achieve eventual future dominance occurred up to 80 m and 20 m from the edge of mature white pine stands after fire and logging, respectively. To attain a similar level of white pine stocking after disturbance, three to four times as many patches of mature white pine need to be left after logging than after fire.
  • Weyenberg, University of Minnesota, Department of Forest Resources, 1530 Cleveland Ave. N., St. Paul, MN 55108, USA E-mail: saw@nn.us
  • Frelich, University of Minnesota, Department of Forest Resources, 1530 Cleveland Ave. N., St. Paul, MN 55108, USA E-mail: freli001@umn.edu (email)
  • Reich, University of Minnesota, Department of Forest Resources, 1530 Cleveland Ave. N., St. Paul, MN 55108, USA E-mail: pbr@nn.us
article id 481, category Research article
K. S. Wang. (2003). Relationship between empty seed and genetic factors in European beech (Fagus sylvatica L.). Silva Fennica vol. 37 no. 4 article id 481. https://doi.org/10.14214/sf.481
Keywords: Fagus sylvatica L.; allozyme; empty seeds; selfing; outcrossing rate; correlation
Abstract | View details | Full text in PDF | Author Info
The relationship between percentage of empty seed (Pes) and genetic factors was explored in an isolated stand of European beech (Fagus sylvatica L.). Nine allozyme loci (GOT-B, IDH-A, LAP-A, MDH-B, MDH-C, MNR-A, 6-PGDH-A, PGI-B and PGM-A) were used to estimate genetic factors. Pes ranged from 4.8% to 40.9% for seed samples of 91 trees within the stand and showed an approximate normal distribution. The average Pes was 21.4% and the repeatability of Pes was 43.4%. The multilocus estimate for outcrossing rate (tm) based on seed samples of 30 trees within the stand was 1.015 (SE = 0.011) and the mean single locus estimate was slightly higher at 1.061 (SE = 0.026). No evidence of biparental inbreeding was found. Weak positive correlation between Pes and maximum selfing rate as well as and significant negative correlation between Pes and multilocus outcrossing rate indicated that self-fertilization may be explained as one of the important causes of empty seeds in beech.
  • Wang, Program in Genetics and Genomic Biology, Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, M5G 1X8, Canada E-mail: kshengw@yahoo.ca (email)
article id 515, category Research article
Juho Rantala, Kari Väätäinen, Nuutti Kiljunen, Pertti Harstela. (2003). Economic evaluation of container seedling packing and disinfection machinery. Silva Fennica vol. 37 no. 1 article id 515. https://doi.org/10.14214/sf.515
Keywords: economies of scale; nursery technology; mechanisation; container seedlings; packing;
Abstract | View details | Full text in PDF | Author Info
Productivity and costs of packing container seedlings were studied in a mechanised line for packing and disinfecting seedling trays. The hypothesis was that adequate cost-efficiency could be achieved when some common principles of mechanisation were applied. Results indicated that the unit costs are lower than those of manual packing, if these principles were applied and the annual number of packed seedlings exceeded 6 million. However, most of the nurseries in Finland are still too small to gain a real advantage from large-scale production.
  • Rantala, Finnish Forest Research Institute, Suonenjoki Research Station, FIN-77600 Suonenjoki, Finland E-mail: juho.rantala@metla.fi (email)
  • Väätäinen, Finnish Forest Research Institute, Joensuu Research Centre, FIN-80101 Joensuu, Finland E-mail: kv@nn.fi
  • Kiljunen, Finnish Forest Research Institute, Suonenjoki Research Station, FIN-77600 Suonenjoki, Finland E-mail: nk@nn.fi
  • Harstela, Finnish Forest Research Institute, Suonenjoki Research Station, FIN-77600 Suonenjoki, Finland E-mail: ph@nn.fi
article id 509, category Research article
Michelle de Chantal, Laura Eskola, Hannu Ilvesniemi, Kari Leinonen, Carl Johan Westman. (2003). Early establishment of Pinus sylvestris and Picea abies sown on soil freshly prepared and after stabilisation. Silva Fennica vol. 37 no. 1 article id 509. https://doi.org/10.14214/sf.509
Keywords: Norway spruce; site preparation; Scots pine; direct seeding; soil properties
Abstract | View details | Full text in PDF | Author Info
The aim of this study is to investigate the early establishment of Pinus sylvestris L. (Scots pine) and Picea abies (L.) Karst. (Norway spruce) seedlings on soil freshly prepared and soil left to stabilise for one year after preparation. Three site preparation treatments were studied: exposed C horizon, mound (broken O/E/B horizon piled upside down over undisturbed forest floor), and exposed E/B horizon. The years investigated were different in terms of weather, one being rainy and the other one dry. As such, emergence was very low in the dry year. Content of fine silt particles, bulk density, water retention, air-filled porosity, loss-on-ignition, and near saturated hydraulic conductivity did not differ statistically between fresh and stabilised soil. Nevertheless, early establishment of P. sylvestris seedlings was improved on exposed C and E/B horizon after one year of soil stabilisation. In contrast, early establishment of P. sylvestris on mounds, and that of P. abies on all types of site preparation treatments were not improved by soil stabilisation. In addition, mortality due to frost heaving did not differ significantly between freshly prepared and stabilised soil. Considering the fact that growing season climate had a great influence on the sowing outcome, and that early establishment is also affected by other factors that vary yearly, such as predation, seedbed receptivity, and competition from vegetation, it may not be advantageous to wait for soil to stabilise before regenerating from seeds.
  • Chantal, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: michelle.dechantal@helsinki.fi (email)
  • Eskola, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: le@nn.fi
  • Ilvesniemi, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: hi@nn.fi
  • Leinonen, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: kl@nn.fi
  • Westman, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: cjw@nn.fi
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 592, category Research article
Marja-Liisa Juntunen. (2001). Use of pesticides in Finnish forest nurseries in 1996. Silva Fennica vol. 35 no. 2 article id 592. https://doi.org/10.14214/sf.592
Keywords: herbicides; fungicides; insecticides; seedlings; survey study
Abstract | View details | Full text in PDF | Author Info
In 1996 a questionnaire on seedling production and use of pesticides was sent to 33 forest nurseries in Finland. Twenty-eight nurseries answered the questionnaire; thus the survey covered about 80% of the Finnish production of forest seedlings. According to this study, the Finnish nurseries together are using about 1000 kilograms of pesticides (as active ingredient, a.i.) annually. The most used herbicide was terbutylazine (Gardoprim-Neste®), and half of the total amount of fungicide used was chlorothalonil (Bravo 500®). Three fourths of the insecticide products had permethrin as the active ingredient. The nurseries applied, on average, 1.7 kg pesticides (a.i.)/ha annually, although the amount varied considerably between nurseries. In production of container seedlings the highest mean amounts of pesticides were applied to pine seedlings (9.5 kg/ha) and the lowest to spruce seedlings (0.9 kg/ha). To the fields of bareroot seedlings the nurseries applied, on average, 3.9 kg pesticides (a.i.)/ha. Mean amounts of pesticide (a.i.) per 1000 seedlings grown in containers were almost the same for birch and pine production, 1.6 and 1.7 grams, respectively; for production of spruce seedlings the comparable values were less than 0.5 grams. For production of bareroot seedlings the nurseries used about four times more pesticides than for container seedlings.
  • Juntunen, The Finnish Forest Research Institute, Suonenjoki Research Station, FIN-77600 Suonenjoki, Finland E-mail: marja-liisa.juntunen@metla.fi (email)
article id 661, category Research article
Eira-Maija Savonen, Anna Saarsalmi. (1999). Effects of clone and fertilization on the seed and foliar chemical composition of Scots pine (Pinus sylvestris) grafts. Silva Fennica vol. 33 no. 2 article id 661. https://doi.org/10.14214/sf.661
Keywords: needles; Scots pine; nutrient concentration; seeds; seed orchards
Abstract | View details | Full text in PDF | Author Info
Effects of clone and fertilization on the seed and foliar nutrient concentrations of Scots pine grafts were investigated in a seed orchard in southern Finland. The seed and foliar samples for chemical analyses were collected during winters 1985–86 and 1988–89 from 39 grafts per clone fertilized in spring 1986. There were 6 clones and 13 treatments for each clone with three replications. The treatments consisted of N, P, K in various combinations, micronutrients, wood ash and grass control. Macro- (N, P, K, Ca, Mg) and micronutrients (Cu, Zn, B) were analysed. There were statistically significant differences between the clones in seed nutrient concentrations. The variation of the K, Mg, Ca, Zn and Cu concentrations between the two study years was considerably larger in the seeds than in the needles. The concentrations of these elements in the seeds were low in the year of an abundant seed crop in spite of fertilization. This had, however, no negative effects on germination of seeds. The proportions of crude fat and crude protein were high in both years (34% and 35% in 1985 ; 33% and 38% in 1988). Fertilization had only minor or no effect at all on the seed chemical composition in the orchard with a satisfactory nutrient status of the soil. Also on the foliar nutrient concentrations the effect of the clone was stronger than that of fertilization. Grafts with large needles produced heavy seeds, which had more storage proteins than the lighter seeds.
  • Savonen, The Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, FIN-39700 Parkano, Finland E-mail: eira-maija.savonen@metla.fi (email)
  • Saarsalmi, The Finnish Forest Research Institute, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: as@nn.fi

Category : Review article

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 688, category Review article
John A. Stanturf, Callie J. Schweitzer, Emile S. Gardiner. (1998). Afforestation of marginal agricultural land in the Lower Mississippi River Alluvial Valley, U.S.A. Silva Fennica vol. 32 no. 3 article id 688. https://doi.org/10.14214/sf.688
Keywords: Populus deltoides; bottomland hardwoods; direct-seeding; Liquidambar styraciflua; Fraxinus pennsylvanica; Quercus nuttallii; Quercus nigra
Abstract | View details | Full text in PDF | Author Info
Afforestation of marginal agricultural land in the Lower Mississippi Alluvial Valley (LMAV) relies on native species, planted mostly in single-species plantations. Hard mast species such as oak and pecan are favored for their value to wildlife, especially on public land. Successful afforestation requires an understanding of site variation within floodplains and matching species preferences and tolerances to site characteristics, in particular to inundation regimes. Soil physical conditions, root aeration, nutrient availability, and moisture availability during the growing season also must be considered in matching species to site. Afforestation methods include planting seedlings or cuttings, and direct-seeding. Both methods can be done by hand or by machine. If good quality seedlings are planted properly and well cared for before planting, the chances for successful establishment are high but complete failures do occur. Mortality and poor growth are caused by many factors: extended post-planting drought or flooding; poor planting or seeding practices; poor quality seed or seedlings; animal depredation; or herbicide drift from aerial application to nearby cropland. More species can be planted, even on continuously flooded sites. Direct-seeding, while limited to heavy-seeded species (oaks and hickories), costs less than 50% of planting seedlings. Growth varies considerably by soil type; most bottomland hardwoods grow best on silt loam and less well on clay soils. Up to 200 000 ha of land in the LMAV subject to spring and early summer backwater flooding could be afforested over the next decade.
  • Stanturf, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: jstantur/srs_stoneville@fs.fed.us (email)
  • Schweitzer, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: cjs@nn.us
  • Gardiner, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: esg@nn.us

Category : Research note

article id 974, category Research note
Kristina Ahnlund Ulvcrona, Lars Karlsson, Ingegerd Backlund, Urban Bergsten. (2013). Comparison of silvicultural regimes of lodgepole pine (Pinus contorta) in Sweden 5 years after precommercial thinning. Silva Fennica vol. 47 no. 3 article id 974. https://doi.org/10.14214/sf.974
Keywords: direct seeding; forest production; corridor thinning; biomass harvest; PCT
Highlights: Management regimes can serve different purposes such as biomass production, pulp and timber production or a combination of those; 30 tons biomass or 38–45 m3 stem volume ha–1 could be derived by schematic corridor thinning (70%) at year 20; Producing large amounts of biomass early in the rotation period does not exclude a conversion into pulp and timber production.
Abstract | Full text in HTML | Full text in PDF | Author Info
Early effects (stem volume, mean diameter at breast height weighted against basal area (Dgv) (Dgv), biomass and damage frequency) of different silvicultural regimes 18-19 years after direct seeding of lodgepole pine in northern Sweden were analysed. A Conventional regime, (i) precommercial thinning (PCT) to 2200 stems ha-1, was compared to: (ii) High biomass production (15 300 stems ha-1, no PCT) with and without corridor thinning at year 20, (iii) production of Large dimension trees (PCT to 1700 stems ha-1), (iv), Combined high biomass production and production of conventional round wood (PCT to 4500 stems ha-1). PCT was done 15 yrs after direct seeding for all PCT treatments. Local biomass functions showed that the regimes aiming at High biomass production displayed ca 144-157% more biomass and 134-143% more stem volume than the Conventional and Large dimension regimes (ca 21 tons and 31 m3 ha-1). Dgv for the 1000 (9.2 cm) and 2000 (8.3 cm) largest trees ha-1 appeared unaffected by regime. By schematic corridor thinning (70% of the total area) at year 20 in the High biomass regime, 27-32 tons of biomass ha-1 and 38-45 m3 ha-1 could be derived while still having a Dgv of the 1000 largest trees ha-1 of about 8 cm. Therefore, this study indicates that it is possible to produce and harvest large amounts of biomass and stem volume early in the rotation period without excluding later pulp and timber production. This initial regime comparison should be continued over time.
  • Ahnlund Ulvcrona, SLU, Forest Biomaterials and Technology, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: kristina.ulvcrona@slu.se (email)
  • Karlsson, SLU, Forest Biomaterials and Technology, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: lars.karlsson@slu.se
  • Backlund, SLU, Forest Biomaterials and Technology, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: ingegerd.backlund@slu.se
  • Bergsten, SLU, Forest Biomaterials and Technology, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: urban.bergsten@slu.se
article id 897, category Research note
Lars Lundqvist, Susanne Spreer, Christer Karlsson. (2013). Volume production in different silvicultural systems for 85 years in a mixed Picea abies–Pinus sylvestris forest in central Sweden. Silva Fennica vol. 47 no. 1 article id 897. https://doi.org/10.14214/sf.897
Keywords: plantation; growth and yield; clear-cutting; silvicultural systems; seed trees; selection system; single-tree selection; diameter limit harvest
Abstract | Full text in HTML | Full text in PDF | Author Info
A long-term comparison of different silvicultural systems was established in 1923 in central Sweden, in an uneven-aged mixed Norway spruce–Scots pine forest (Picea abies (L.) Karst. – Pinus sylvestris L.) with about 85% spruce and 15% pine. The five treatments consisted of two examples of even-aged management 1) clear-cutting followed by planting, and 2) seed tree regeneration, one uneven-aged management 3) selection system, one exploiting treatment 4) diameter limit cut, and 5) one untreated control plot. Each treatment plot was 1 ha, 100 m × 100 m. The plots were measured and managed at irregular intervals, ranging from 7 to 15 years. In 2007–2008 the even-aged treatments and the diameter limit cut were repeated and a new rotation started. Mean annual volume increment during the whole observation period differed widely between the treatments, partly because of differences in species composition over time, with treatment clear-cutting followed by planting at the top, and the control at the bottom. Treatment selection system gave only about 60% of planting, but this was probably largely an effect of too small growing stock during the first roughly 50 years. When the growing stock was increased, periodic annual volume increment increased to about 80% of the mean annual volume increment in the even-aged, planted plot.
  • Lundqvist, Deparment of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: lars.lundqvist@slu.se (email)
  • Spreer, Sveaskog Förvaltnings AB, Ljusdal, Sweden E-mail: susanne.spreer@sveaskog.se
  • Karlsson, Field Research Unit, Swedish University of Agricultural Sciences, Siljansfors, Sweden E-mail: christer.karlsson@slu.se
article id 914, category Research note
Ingegerd Backlund, Urban Bergsten. (2012). Biomass production of dense direct-seeded lodgepole pine (Pinus contorta) at short rotation periods. Silva Fennica vol. 46 no. 4 article id 914. https://doi.org/10.14214/sf.914
Keywords: biomass production; lodgepole pine; direct seeding; Pinus contorta; biorefinery; short rotation
Abstract | View details | Full text in PDF | Author Info
Lodgepole pine (Pinus contorta) is a fast-growing species that is suitable for producing woody biomass in Nordic countries. Direct seeding of this species is cheaper than planting and creates dense, stable stands. The objective of this study was to quantify the stem volume and biomass production of direct seeded lodgepole pine stands grown under different site conditions with different stem densities, at an age that would permit extensive harvesting of biomass. A circle-plot inventory was performed in 16 of the oldest direct seeded lodgepole pine stands in mid-northern Sweden. Stemwood production of almost 200 m3/ha was achieved on average on the best sites, rising to about 300 m3/ha for the best circle-plots within 30 years of direct seeding despite the fact that pre-commercial thinning was made once or twice. This corresponds to 100 and 140 tons of dry weight biomass/ha, respectively. Higher stand stem densities (≥3000 st/ha) yielded more biomass with only slight reductions in diameter at breast height. The development of stem volume with respect to dominant height in direct seeded stands was becoming comparable to that in planted stands with similar spacing. It therefore seems that there is an unutilized potential for cost-effectively growing lodgepole pine in dense stands for biomass production after direct seeding. It may be possible to devise regimes for short(er) rotation forestry that would yield substantial amount of inexpensive biomass for biorefineries within a few decades.
  • Backlund, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: ingegerd.backlund@slu.se (email)
  • Bergsten, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: urban.bergsten@slu.se
article id 118, category Research note
Audrius Menkis, Remigijus Bakys, Vaidotas Lygis, Rimvydas Vasaitis. (2011). Mycorrhization, establishment and growth of outplanted Picea abies seedlings produced under different cultivation systems. Silva Fennica vol. 45 no. 2 article id 118. https://doi.org/10.14214/sf.118
Keywords: forest nursery; cultivation system; ectomycorrhizal fungi; Picea abies seedlings
Abstract | View details | Full text in PDF | Author Info
In forest nurseries seedlings are commonly produced using different cultivation systems which may have a profound effect on the extent of root colonisation by ectomycorrhizal (ECM) fungi and, consequently, on subsequent performance of the outplanted seedlings under field conditions. In this study, we compare effects of bare-root and containerised cultivation systems on mycorrhization, establishment and growth of nursery-produced Picea abies. One hectare experimental plantation was established on poor fertility sandy site. In total, 1250 seedlings of each treatment were planted in rows as ten individual replicates. The results of this study showed that production of P. abies seedlings using containerised system can yield abundant ECM colonisation of seedling roots and significantly improve seedling survival in the field. Some reduction in height increment may occur during the first years as a possible cost for support of ECMs. Study demonstrated that selection of proper cultivation system might result in similar or higher mycorrhization and survival rates of outplanted seedlings than achieved by expensive and laborious artificial mycorrhization.
  • Menkis, Department of Forest Mycology and Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-750 07 Uppsala, Sweden E-mail: audrius.menkis@slu.se (email)
  • Bakys, Department of Forest Mycology and Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-750 07 Uppsala, Sweden E-mail: rb@nn.se
  • Lygis, Laboratory of Phytopathogenic Microorganisms, Institute of Botany at the Nature Research Centre, Vilnius, Lithuania E-mail: vl@nn.lt
  • Vasaitis, Department of Forest Mycology and Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-750 07 Uppsala, Sweden E-mail: rv@nn.se
article id 403, category Research note
Timo Saksa, Juha Heiskanen, Jari Miina, Jaakko Tuomola, Taneli Kolström. (2005). Multilevel modelling of height growth in young Norway spruce plantations in southern Finland. Silva Fennica vol. 39 no. 1 article id 403. https://doi.org/10.14214/sf.403
Keywords: Norway spruce; Picea abies; height growth; mounding; disc trenching; container seedlings; intra-level correlation; variance-component model
Abstract | View details | Full text in PDF | Author Info
Height development of Norway spruce (Picea abies (L.) Karst.) transplants was studied on 22 sites prepared by disc trenching or mounding. At the age of 4–9 years the plantations were surveyed using a multistage sampling design. For every planted spruce on a plot, the past annual height increments were measured as far into the past as possible. Multilevel mixed linear modelling was used to analyse the variation in growth at different levels (year, stand, cluster, plot, tree) and the effects of climatic and site characteristics on height growth. The within-plantation variation in height growth was higher on mounded sites than on disc-trenched sites. The mean temperature and the precipitation sum of the summer months affected height growth positively. Soil characteristics measured from undisturbed soil did not explain the height growth of seedlings on mounded sites, whereas on disc-trenched sites, the depth of the organic layer and the soil temperature had a positive effect and the depth of the eluvial horizon a negative effect. The modelling approach used proved to be a useful method for examining the sources of variation in development of young plantations.
  • Saksa, The Finnish Forest Institute, Suonenjoki Research Station, FI-77600 Suonenjoki, Finland E-mail: ts@nn.fi (email)
  • Heiskanen, The Finnish Forest Institute, Suonenjoki Research Station, FI-77600 Suonenjoki, Finland E-mail: jh@nn.fi
  • Miina, The Finnish Forest Institute, Joensuu Research Centre, P. O. Box 68, FI-80101 Joensuu, Finland E-mail: jm@nn.fi
  • Tuomola, The University of Joensuu, Mekrijärvi Research Station, FI-82900 Ilomantsi, Finland E-mail: jt@nn.fi
  • Kolström, The University of Joensuu, Mekrijärvi Research Station, FI-82900 Ilomantsi, Finland E-mail: tk@nn.fi
article id 609, category Research note
Aleksei Fedorkov. (2001). Climatic adaptation of seed maturity in Scots pine and Norway spruce populations. Silva Fennica vol. 35 no. 1 article id 609. https://doi.org/10.14214/sf.609
Keywords: Norway spruce; Scots pine; climatic adaptation; provenance experiment; seed maturation; X-ray method
Abstract | View details | Full text in PDF | Author Info
Seed maturation of Scots pine and Norway spruce in a provenance experiment at Kortkeros (northern Russia) was examined by the X-ray method. Logarithmic relationships were found between seed anatomy development and long-term average thermal sum. Seed development in the northern populations of Scots pine and Norway spruce was a little faster than in the southern ones.
  • Fedorkov, Russian Academy of Sciences, Komi Science Centre, Institute of Biology, Kommunisticheskya St., 28, 167610 Syktyvkar, Russia E-mail: fedorkov@ib.komisc.ru (email)
article id 624, category Research note
Hashim Ali El Atta. (2000). Effect of diet and seed pretreatment on the biology of Bruchidius uberatus (Coleoptera, Bruchidae). Silva Fennica vol. 34 no. 4 article id 624. https://doi.org/10.14214/sf.624
Keywords: Bruchidius uberatus; Bruchidae; Acacia nilotica; seed borer biology
Abstract | View details | Full text in PDF | Author Info
Diet significantly (P < 0.0001) affected fecundity of Bruchidius uberatus Fahraeus. Provision of 1% sugar solution increased fecundity from 15 eggs/female to 47. Furthermore, sugar solution prolonged significantly the oviposition period of B. uberatus from one week to two weeks. Diet also significantly (P < 0.0001) increased adult longevity. Mean adult longevity recorded was 3, 7 and 13 days in control, water and sugar treatments, respectively. Seed pretreatment had a highly significant impact on the various developmental stages of B. uberatus. Maximum egg hatchability occurred in non-husked Acacia nilotica (L.) Willd. ex Del. seeds (83%), moderate in de-husked seeds (74%) and least in seeds presoaked in concentrated sulphuric acid (42%). The frequency of larvae that developed successfully into pupae was greatest in non-husked seeds (72%), nevertheless in de-husked and acid pretreated seeds, absolutely no larvae developed into pupae and hence the adult stage was not reached in these two treatments. Thus, de-husking and acid pretreatment of A. nilotica seeds is highly recommended.
  • El Atta, University of Khartoum, Faculty of Forestry, Department of Forest Conservation and Protection, Shambat, Sudan E-mail: hashimelatta@yahoo.com (email)

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