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Silva Fennica 1926-1997
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Acta Forestalia Fennica
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Articles containing the keyword 'tree'

Category : Article

article id 5629, category Article
Risto Sievänen, Eero Nikinmaa, Jari Perttunen. (1997). Evaluation of importance of sapwood senescence on tree growth using the model Lignum. Silva Fennica vol. 31 no. 3 article id 5629. https://doi.org/10.14214/sf.a8531
Keywords: Pinus sylvestris; growth; growth model; pipe-model theory; sapwood senescence; open-grown trees
Abstract | View details | Full text in PDF | Author Info

The effects of two alternative formulations of sapwood senescence on the behaviour of model LIGNUM (with parameter values adjusted for Scots pine (Pinus sylvestris L.) growing southern Finland) were studied. The two alternatives were autonomous sapwood senescence assuming a maximum age for the tree ring, and sapwood senescence that is controlled by the mortality of foliage. For the latter alternative two hypothetical further mechanisms were stipulated. All the formulations were implemented in LIGNUM. Simulations were made with all model variants for fertile and poor soil conditions using high, normal and low rates of foliage mortality. The simulation results were compared against of a data set consisting of 11 open grown Scots pine trees from southern Finland. Observations of heartwood proportion were used in this study. They show that heartwood starts to increase in trees from age of approximately 20 years onwards. The simulation results showed no differences between fertile and poor soil conditions as regards heartwood formation. Of the variants of foliage-controlled sapwood senescence the one where death of sapwood in a tree segment induces sapwood senescence in the tree parts below only slightly was the best. This and the autonomous sapwood senescence corresponded equally well to the observations. In order to make more refined conclusions additional data and simulations are necessary.

  • Sievänen, E-mail: rs@mm.unknown (email)
  • Nikinmaa, E-mail: en@mm.unknown
  • Perttunen, E-mail: jp@mm.unknown
article id 5626, category Article
Winfried Kurth, Branislav Sloboda. (1997). Growth grammars simulating trees – an extension of L-systems incorporating local variables and sensitivity. Silva Fennica vol. 31 no. 3 article id 5626. https://doi.org/10.14214/sf.a8527
Keywords: tree growth; competition; allocation; morphology; tree architecture; L-systems; sensitivity; tree structure
Abstract | View details | Full text in PDF | Author Info

The rule-based formal language of "stochastic sensitive growth grammars" was designed to describe algorithmically the changing morphology of forest trees during their lifetime under the impact of endogenous and exogenous factors, and to generate 3-D simulations of tree structures in a systematic manner. The description in the form of grammars allows the precise specification of structural models with functional components. These grammars (extended L-systems) can be interpreted by the software GROGRA (Growth grammar interpreter) yielding time series of attributed 3-D structures representing plants. With some recent extensions of the growth-grammar language (sensitive functions, local variables) it is possible to model environmental control of shoot growth and some simple allocation strategies, and to obtain typical competition effects in tree stands qualitatively in the model.

  • Kurth, E-mail: wk@mm.unknown (email)
  • Sloboda, E-mail: bs@mm.unknown
article id 5625, category Article
Thomas Früh. (1997). Simulation of water flow in the branched tree architecture. Silva Fennica vol. 31 no. 3 article id 5625. https://doi.org/10.14214/sf.a8526
Keywords: drought stress; modelling; branches; tree architecture; water flow; finite difference method; hydraulic network; numerical model; hydraulic system
Abstract | View details | Full text in PDF | Author Info

The model HYDRA, which simulates water flow in the branched tree architecture, is characterized. Empirical studies of the last decades give strong evidence for a close structure-function linkage in the case of tree water flow. Like stomatal regulation, spatial patterns of leaf specific conductivity can be regarded as a strategy counteracting conductivity losses, which may arise under drought. Branching-oriented water flow simulation may help to understand how damaging and compensating mechanisms interact within the hydraulic network of trees. Furthermore, a coupling of hydraulic to morphological modelling is a prerequisite if water flow shall be linked to other processes. Basic assumptions of the tree water flow model HYDRA are mass conservation, Darcy's law and the spatial homogeneity of capacitance and axial conductivity. Soil water potential is given as a one-sided border condition. Water flow is driven by transpiration. For unbranched regions these principles are condensed to a nonlinear diffusion equation, which serves as a continuous reference for the discrete method tailored to the specific features of the hydraulic network. The mathematical derivation and model tests indicate that the realization of the basic assumptions is reproducible and sufficiently exact. Moreover, structure and function are coupled in a flexible and computationally efficient manner. Thus, HYDRA may serve as a tool for the comparative study of different tree architectures in terms of hydraulic function.

  • Früh, E-mail: tf@mm.unknown (email)
article id 5624, category Article
Hervé Sinoquet, Christophe Godin, Pierre Rivet. (1997). Assessment of the three-dimensional architecture of walnut trees using digitising. Silva Fennica vol. 31 no. 3 article id 5624. https://doi.org/10.14214/sf.a8525
Keywords: digitising; crown structure; tree architecture; Juglans regia; topology; geometry; shoot level; shoot morphology
Abstract | View details | Full text in PDF | Author Info

A method for the measurement of the three-dimensional (3D) architecture of trees was applied to describe two 20-year-old walnut trees, one of them is a timber tree while the other is a fruit tree. The method works at the shoot level and simultaneously describes the plant topology, the plant geometry and the shoot morphology. The method uses a 3D digitiser (3SPACE® FASTRAK®, Polhemus Inc.) associated with software DiplAmi designed for digitiser control and data acquisition management. Plant images may be reconstructed from the data set by using the ray tracing software POV-Ray. Visual comparison between photographs of the walnut trees and images synthesised from digitising was satisfactory. Distribution of basal shoot diameter, as well as leaf area and fruit distributions for both the timber and the fruit tree were non-uniformly distributed in the crown volume. Gradients were likely to be related to the light distribution within the tree. This is in agreement with previous experimental results on several tree species, and also with the predictions of tree architecture models based on light-vegetation interactions.

  • Sinoquet, E-mail: hs@mm.unknown (email)
  • Godin, E-mail: cg@mm.unknown
  • Rivet, E-mail: pr@mm.unknown
article id 5622, category Article
Christine Deleuze, François Houllier. (1997). A transport model for tree ring width. Silva Fennica vol. 31 no. 3 article id 5622. https://doi.org/10.14214/sf.a8523
Keywords: carbon; optimization; tree growth; stem taper; allocation; environment; wood distribution; functional balance; Münch’s theory; partitioning; process-model; reaction-diffusion; Thornley's model; silvicultural treatments
Abstract | View details | Full text in PDF | Author Info

Process-based tree growth models are recognized to be flexible tools which are valuable for investigating tree growth in relation to changing environment or silvicultural treatments. In the context of forestry, we address two key modelling problems: allocation of growth which determines total wood production, and distribution of wood along the stem which determines stem form and wood quality. Growth allocation and distribution are the outcome of carbon translocation, which may be described by the Munch theory. We propose a simpler gradient process to describe the carbon distribution in the phloem of conifers. This model is a reformulation of a carbon diffusion-like process proposed by Thornley in 1972. By taking into account the continuity of the cambium along the stem, we obtain a one-dimensional reaction-diffusion model which describes both growth allocation between foliage, stem and roots, and growth distribution along the stem. Distribution of wood along the stem is then regarded as an allocation process at a smaller scale. A preliminary sensitivity analysis is presented. The model predicts a strong relationship between morphology and foliage-root allocation. It also suggests how empirical data, such as stem analysis, could be used to calibrate and validate allocation rules in process-based growth models.

  • Deleuze, E-mail: cd@mm.unknown (email)
  • Houllier, E-mail: fh@mm.unknown
article id 5608, category Article
Harri Mäkinen. (1997). Possibilities of competition indices to describe competitive differences between Scots pine families. Silva Fennica vol. 31 no. 1 article id 5608. https://doi.org/10.14214/sf.a8509
Keywords: Pinus sylvestris; Scots pine; tree breeding; stand density; tree improvement; competition indices
Abstract | View details | Full text in PDF | Author Info

Possibilities of distance-independent and -dependent competition indices to describe the competition stress of an individual tree was studied in Southern Finland. Five half-sib open-pollinated families and one check lot of Scots pine (Pinus sylvestris L.) was used as study material in order to analyse competitive interactions of crown form and stand density variation. Almost all competition indices correlated strongly with radial increment. Thus distance-independent indices were adequate to describe competition in young row plantations, where distance effects between trees were implicitly eliminated. Correlations between indices and height increment were not significant. Along with the increase in competition, the width and length of the crown and the diameter increment of the stem of some narrow-crowned families decreased slowly compared to wide-crowned families.

  • Mäkinen, E-mail: hm@mm.unknown (email)
article id 5600, category Article
Anton K. Chtchoukine. (1996). North European platyphyllous forests: biodiversity dynamics and climate changes in northwest European Russia. Silva Fennica vol. 30 no. 2–3 article id 5600. https://doi.org/10.14214/sf.a9245
Keywords: biodiversity; reforestation; climatic change; tree species composition; broadleaved forests; deciduous forests
Abstract | View details | Full text in PDF | Author Info

Distribution, biodiversity and reforestation dynamics of the platyphyllous forests in the Northwest European Russia were investigated. Data assembled from 21 landscape regions (250–350 km2 each) show special features of small-leaved lime (Tilia cordata Mill., Norway maple (Acer platanoides L.), mountain elm (Ulmus glabra Mill.) and English oak (Qurecus robur L.) reforestation during the last two decades. New tendencies were found for the taiga areas with natural Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) vegetation. Natural platyphyllous reforestation in cut spruce areas poses as supposed a special question for forest management policy in the relationship to global climate changes. Feasible unsustainability of the common types of succession (Norway spruce - European birch (Betula pendula Roth); Norway spruce - European aspen (Populus tremula L.)) is discussed. Biodiversity of herbs, shrubs and tree species of platyphyllous forests is high and complex and is situated in 4–15 old-growth relics in each landscape region. Low-level genotype heterogeneity of nemoral flora species of such isolated populations is presumed. Special biodiversity conservation regulations are proposed.

  • Chtchoukine, E-mail: ac@mm.unknown (email)
article id 5574, category Article
Jouni Vettenranta. (1996). Effect of species composition on economic return in a mixed stand of Norway spruce and Scots pine. Silva Fennica vol. 30 no. 1 article id 5574. https://doi.org/10.14214/sf.a9219
Keywords: Pinus sylvestris; Picea abies; net present value; mixed forests; growth models; tree species composition; forest management practices; felling methods; valuation; soil expectation value; treatment programme
Abstract | View details | Full text in PDF | Author Info

The effect of species mixture was studied in a mixed stand of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) by simulating around 100 different treatment schedules during the rotation in a naturally regenerated even-aged stand located on a site of medium fertility in North Karelia, Finland. Both thinning from below and thinning from above were applied. Optimum rotations were determined by maximising the net present value calculated to infinity and different treatment schedules were compared with the net present value over one rotation as per rotation applied. In the optimum treatment programme, the proportion of pines was decreased by half of the basal area in the first thinning stage and by the end of the rotation to about one third. In thinning from above, the proportion of pines can be maintained at a slightly higher level. It is economically profitable to maintain the growing stock capital at approximately the level recommended by Forest Centre Tapio, a semi-governmental forestry authority. With non-optimum species composition, the loss in net present value over one rotation can be about 10 % in thinning from below and about 20 % in thinning from above.

  • Vettenranta, E-mail: jv@mm.unknown (email)
article id 5561, category Article
Jari Liski. (1995). Variation in soil organic carbon and thickness of soil horizons within a boreal forest stand – effect of trees and implications for sampling. Silva Fennica vol. 29 no. 4 article id 5561. https://doi.org/10.14214/sf.a9212
Keywords: Pinus sylvestris; soil carbon; spatial variation; soil formation; soil morphology; tree effects; soil sampling; geostatics
Abstract | View details | Full text in PDF | Author Info

Spatial variation in the density of soil organic carbon (kg/m2) and the thickness of soil horizons (F/H, E) were investigated in a 6 m x 8 m area in Scots pine (Pinus sylvestris L.) stand in Southern Finland for designing an effective sampling for the C density and studying the effect of trees on the variation. The horizon thickness of the podzolized soil were measured on a total of 126 soil cores (50 cm deep) and the C density of the organic F/H and 0–10 cm, 10–20 cm and 20–40 cm mineral soil layers was analysed.

The C density varied 3–5 fold within the layers and the coefficients of variation ranged from 22 % to 40%. Considering the gain in confidence per sample, 8–10 samples were suggested for estimating the mean C density in the F/H and 0–40 cm layers, although about 30 samples are needed for 10% confidence in the mean. The C densities and horizon thicknesses were spatially dependent within the distances of 1–8 m, the spatial dependence accounting for 43–86% of the total variance. The F/H layer was thicker and contained more C within 1–3 m radius from trees. In the 10–20 cm and 20–40 cm layers (B horizon) the C density also increased towards the trees, but more pronouncedly in the immediate vicinity of the stems. Because the spatial patterning of the E horizon thickness was similar, the increase was attributed to stemflow and precipitation of organic compounds in the podzol B horizon.

  • Liski, E-mail: jl@mm.unknown (email)
article id 5559, category Article
Jari Hynynen. (1995). Predicting the growth response to thinning for Scots pine stands using individual-tree growth models. Silva Fennica vol. 29 no. 3 article id 5559. https://doi.org/10.14214/sf.a9210
Keywords: Pinus sylvestris; thinnings; height; diameter; stem form; growth models; individual-tree; distance-dependent
Abstract | View details | Full text in PDF | Author Info

Individual tree-growth models for diameter and height, and a model for the cylindrical stem form factor are presented. The aims of the study were to examine modelling methods in predicting growth response to thinning, and to develop individual-tree, distance-independent growth models for predicting the development of thinned and unthinned stands of Scots pine (Pinus sylvestris L.). The models were constructed to be applicable in simulation systems used in practical forest management planning. The models were based on data obtained from eleven permanent thinning experiments located in even-aged Scots pine stands in Southern and Central Finland.

Two alternative models were developed to predict tree diameter growth in thinned and unthinned stands. In the first model, the effect of stand density was described using stand basal area. In the alternative model, an explicit variable was incorporated referring to the relative growth response due to thinning. The magnitude of the growth response was expressed as a function of thinning intensity. The Weibull function was employed to describe the temporal distribution of the thinning response. Both models resulted in unbiased predictions in unthinned and in moderately thinned stands. An explicit thinning variable was needed for unbiased growth prediction in heavily thinned stands, and in order to correctly predict the dynamics of the growth response.

In the height growth model, no explicit thinnning variable referring thinning was necessary for growth prediction in thinned stands. The stem form factor was predicted using the model that included tree diameter and tree height as regressor variables. According to the results obtained, the information on the changes in the diameter/height ratio following the thinning is sufficient to predict the change in stem form.

  • Hynynen, E-mail: jh@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 5506, category Article
Risto Heikkilä, Sauli Härkönen. (1993). Moose (Alces alces L.) browsing in young Scots pine stands in relation to the characteristics of their winter habitats. Silva Fennica vol. 27 no. 2 article id 5506. https://doi.org/10.14214/sf.a15667
Keywords: Pinus sylvestris; deciduous trees; Scots pine; Alces alces; mixed forests; landscape ecology; moose; feeding behaviour; carrying capacity; browsing
Abstract | View details | Full text in PDF | Author Info

Moose (Alces alces L.) browsing was studied in young Scots pine (Pinus sylvestris L.) stands mixed with deciduous trees in high-density winter ranges. The proportional use of twig biomass decreased as the availability increased. The total as well as proportional biomass consumption were higher on the moist than on the dry type of forest. The per tree consumption of pine was higher on the moist type, where the availability of pine was lower. Deciduous trees were more consumed on the moist type, where their availability was relatively high. The consumption of pine saplings increased as the availability of birch increased. Pine stem breakages were most numerous when birch occurred as overgrowth above pine and at high birch densities. The availability of other deciduous tree species did not correlate with browsing intensity of Scots pine. Moose browsing had seriously inhibited the development of Scots pines in 6% of the stands, over 60% of available biomass having been removed. Rowan and aspen were commonly over-browsed and their height growth was inhibited, which occurred rarely by birch. There was no difference in the proportion of young stands in forest areas with high and low moose density. A high proportion of peatland forests was found to indicate relatively good feeding habitats in the high-density areas.

The PDF includes an abstract in Finnish.

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

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

  • Häggman, E-mail: hh@mm.unknown (email)
article id 5465, category Article
Gösta Eriksson. (1991). Challenges for forest geneticists. Silva Fennica vol. 25 no. 4 article id 5465. https://doi.org/10.14214/sf.a15623
Keywords: tree breeding; dormancy; forest research; phenotypic plasticity; mixed populations; hardiness; change of environment
Abstract | View details | Full text in PDF | Author Info

Studies of phenotypic as well as mixed population plasticities are urgently needed in a world that supposedly experiences a gradual change of its environment. It is important to understand that man creates his environment and silviculture. This is one of the reasons why for breeding it cannot be expected to find optimal phenotypes in nature. Other reasons are the phylogenetic constraints and migration of pollen and seeds.

Forest genetics up to now is characterized by the study of one trait at a time. There is an urgent need for simultaneous analysis of several traits by the aid of genetic correlations or multivariate analysis. Generally there is a need for inclusion of larger numbers of genetic entries in forest genetic investigations.

For the long-rotation-time species there is a need to determine the curves for degree of dormancy and hardiness during the annual cycle. Information of plasticity in two-dimensional environments like water availability and temperature is needed. Studies on nutrient utilization and acquisition will tell us whether or not we must have different breeding populations for different soil fertilities. An understanding of the phase changes between juvenile and adult opens up possible applications such as faster generation turn-over in the breeding population via early flowering and early testing as well as better plants for frost-prone and weedy sites.

  • Eriksson, E-mail: ge@mm.unknown (email)
article id 5464, category Article
Donald I. Dickmann. (1991). Role of physiology in forest tree improvement. Silva Fennica vol. 25 no. 4 article id 5464. https://doi.org/10.14214/sf.a15622
Keywords: flowering; tree breeding; selection criteria; plant physiology; biotechnology; tree improvement; adaptability; ideotypes
Abstract | View details | Full text in PDF | Author Info

The paper introduces different ways plant physiology research can avail the process of tree improvement. The breeding of tree cultivars that efficiently produce a particular wood product or amenity will be an important aspect of forest management. What physiologist can provide to breeders and genetic engineers is the opportunity to move their work from empirical level towards a more theoretical level, and help to make breeding more predictable and more precise in its objectives. The areas of research discussed in the paper are biotechnology, flowering, selection criteria, adaptability and application of ideotypes.

  • Dickmann, E-mail: dd@mm.unknown (email)
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 5461, category Article
Run-Peng Wei, Dag Lindgren. (1991). Selection effects on diversity and genetic gain. Silva Fennica vol. 25 no. 4 article id 5461. https://doi.org/10.14214/sf.a15619
Keywords: tree breeding; phenotypic selection; truncation selection; combined index; in-breeding
Abstract | View details | Full text in PDF | Author Info

Four different methods of truncation selection were studied in a population consisting of a large number of unrelated full sib families of equal size: phenotype selection, family selection, within-family selection and combined index selection (optimal weighting of individual and family performance to get the best prediction of breeding value). Methods were developed for calculating diversity (”relative effective family number”) for the different selection methods. Numerical calculations were made for genetic gain and diversity. Model assumptions are additive gene control and normal distribution. Phenotypic was good at high heritabilities and between family at low heritabilities. Loss of diversity was strongly dependent on selection method and selection strength. Compared at the same diversity, genetic gain was lower for combined index compared to phenotypic. There is a need for methods combining the goals gain and diversity.

The PDF includes an abstract in Finnish.

  • Wei, E-mail: rw@mm.unknown (email)
  • Lindgren, E-mail: dl@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 5411, category Article
Eero Paavilainen. (1990). Effect of refertilization of pine and birch stands on a drained fertile mire. Silva Fennica vol. 24 no. 1 article id 5411. https://doi.org/10.14214/sf.a15563
Original keywords: mänty; koivu; turvemaat; ojitetut suot; hieskoivu; jatkolannoitus; hivenravinteet
English keywords: Pinus sylvestris; Betula; fertilization; Betula pubescens; drained peatlands; tree litter; micronutrients
Abstract | View details | Full text in PDF | Author Info

Refertilization with PK, about 15 years after the first fertilizer application, increased tree growth and the amount of nutrients in tree litter in Scots pine (Pinus sylvestris L.) and birch (mainly Betula pubescens Erhr.) stands on a drained fertile mire in Northern Finland (65°34 N’, 25°42’ E). The increase in growth and nutrient contents after refertilization was greatest in the mature pine stand where the application of nitrogen and micronutrients gave an additional response compared to the PK-application.

The PDF includes an abstract in Finnish.

  • Paavilainen, E-mail: ep@mm.unknown (email)
article id 5404, category Article
Pentti Alho. (1990). Suomen metsittyminen jääkauden jälkeen. Silva Fennica vol. 24 no. 1 article id 5404. https://doi.org/10.14214/sf.a15556
English title: The history of forests in Finland after the last ice age.
Original keywords: puulajit; jääkausi; metsittyminen; luonnonhistoria
English keywords: tree species; review articles; natural afforestation; ice age; natural history; post glacial
Abstract | View details | Full text in PDF | Author Info

Based on literature this paper describes the natural afforestation of Finland that took place after the last ice age and the changes which have taken place during the last 10,000 years. The origin and development of the vegetation and trees are related to the changes in the edaphic and climatic factors. The first tree species to arrive in Finland were the primary colonizing species, birch and Scots pine. The appearance of Norway spruce dates back to about 5000 B.P. There have been great changes in the species composition of Finnish forests during the last several thousands of years but some 2,000–3,000 years ago the various species reached their present balance. The epoch of naural forests, which had lasted some 9,500 years, came to a conclusion, however, when man started to have a marked effect on the forest’s development 300–400 years ago.

The PDF includes an abstract in English.

  • Alho, E-mail: pa@mm.unknown (email)
article id 5385, category Article
Timo Kuuluvainen. (1989). Branching dynamics in young Scots pine. Silva Fennica vol. 23 no. 3 article id 5385. https://doi.org/10.14214/sf.a15542
Keywords: Pinus sylvestris; biomass production; branching; tree architecture; bifuraction; modular construction; shoot demography
Abstract | View details | Full text in PDF | Author Info

The development of shoot number and shoot properties was examined in successive shoot cohorts of young widely-spaced Scots pine trees (Pinus sylvestris L.) growing in a progeny trial. This was accomplished by reconstructing the branching process of the trees over a period of five years, from tree age 4 to 8. During this time the number of shoots in successive shoot cohorts increased rapidly, while at the same time the mean shoot length decreased. The decrease in shoot lengths from older to younger shoots was accompanied by a decline in the bifuraction frequency of the shoots. In general, rapid changes occurred in the branching characteristics during the yearly development of the trees. The variation in the branching characteristics was reflected in the development of the architecture and biomass production of the trees.

The PDF includes an abstract in Finnish.

  • Kuuluvainen, E-mail: tk@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 5376, category Article
Timo Pukkala. (1989). Predicting diameter growth in even-aged Scots pine stands with a spatial and non-spatial model. Silva Fennica vol. 23 no. 2 article id 5376. https://doi.org/10.14214/sf.a15533
Keywords: Pinus sylvestris; growth prediction; spatial distribution; growth models; tree models
Abstract | View details | Full text in PDF | Author Info

The single tree growth models presented in this study were based on about 4,000 trees measured in 50 even-aged Scots pine (Pinus sylvestris L.) sample plots with varying density, spatial pattern of trees and stand age. Predictors that used information about tree locations decreased the relative standard error of estimate by 10 percentage points (15%), if past growth was not used as a predictor, and about 15 percentage points (30%) when past growth was one of the predictors. When ranked according to the degree of determination, the best growth models were obtained for the basal area increment, the next best for relative growth, and the poorest for diameter increment. The past growth decreased the relative standard error of estimate by 15–20 percentage points, but did not make the spatial predictors unnecessary. The degree of determination of the spatial basal area growth model was almost 80% if the past growth was unknown and almost 90% if the past growth was known. Variables that described the amount of removed competition did not improve the growth models.

The PDF includes an abstract in Finnish.

  • Pukkala, E-mail: tp@mm.unknown (email)
article id 5375, category Article
Timo Pukkala. (1989). Prediction of tree diameter and height in a Scots pine stand as a function of the spatial pattern of trees. Silva Fennica vol. 23 no. 2 article id 5375. https://doi.org/10.14214/sf.a15532
Keywords: Pinus sylvestris; diameter distribution; competition; spatial distribution; simulations studies; tree models
Abstract | View details | Full text in PDF | Author Info

The study presents two methods of predicting tree dimensions in a Scots pine (Pinus sylvestris L.) stand if only the location of trees is known. The first method predicts the tree diameter from the spatial location of neighbours. In the second method the diameter distribution of a subarea is estimated from the local stand density. This distribution is then sampled to obtain diameters. In both methods the tree height is predicted with a spatial model on the basis of diameters and locations of trees. The main purpose of the presented models is to generate realistic stands for simulation studies.

The PDF includes an abstract in Finnish.

  • Pukkala, E-mail: tp@mm.unknown (email)
article id 5349, category Article
Raphael E. L. Ole-Meiludie, Goodseldah K. Pamba. (1988). Time study on different techniques for nursery pot filling operation. Silva Fennica vol. 22 no. 2 article id 5349. https://doi.org/10.14214/sf.a15506
Keywords: productivity; time study; Tanzania; nursery pot filling; forest tree nursery
Abstract | View details | Full text in PDF | Author Info

Time study on different techniques in nursery pot filling operations at SUA Training Forest in Northern Tanzania was conducted. The results showed that improved tools and work place design significantly decreased the operation time, hence increased productivity. In addition, worker’s comfort was generally increased.

The PDF includes a summary in Finnish.

  • Ole-Meiludie, E-mail: ro@mm.unknown (email)
  • Pamba, E-mail: gp@mm.unknown
article id 5347, category Article
Timo Kuuluvainen, Markku Kanninen, Juha-Pekka Salmi. (1988). Tree architecture in young Scots pine: properties, spatial distribution and relationships of components of tree architecture. Silva Fennica vol. 22 no. 2 article id 5347. https://doi.org/10.14214/sf.a15504
Keywords: Pinus sylvestris; crown architecture; biomass production; branching pattern; tree ideotype
Abstract | View details | Full text in PDF | Author Info

The architecture of Scots pine (Pinus sylvestris L.) was studied in an eight-year-old progeny test. The measurements included characteristics of crown structure, spatial distribution of shoots and yield components. The spatial distribution of shoots showed striking between-tree differences, and two extreme distribution patterns were detected. One represented a non-layered structure with a vertically relative even shoot distribution, and the other a layered structure with a vertically highly uneven shoot distribution.

Close correlations existed between several components of tree architecture and it is suggested that changes in the phenotypic architecture in Scots pine follow an epigenetic pattern, which enables the prediction of adaptational changes in structural components. The structural characteristics related to high above-ground biomass were a long crown, high total shoot length, high number of branches per whorl and big shoots of low needle density occupying a big share of the crown volume.

The PDF includes a summary in Finnish.

  • Kuuluvainen, E-mail: tk@mm.unknown (email)
  • Kanninen, E-mail: mk@mm.unknown
  • Salmi, E-mail: js@mm.unknown
article id 5328, category Article
Max Guignard. (1987). The tree in the Paris and Helsinki areas. Silva Fennica vol. 21 no. 4 article id 5328. https://doi.org/10.14214/sf.a15485
Keywords: park trees; urban environment; urban landscape
Abstract | View details | Full text in PDF | Author Info

The paper describes some examples from Paris and Helsinki areas, where trees are essential landscape elements. It is typical in France to plant trees around town squares, market places and along streets and roads. In Finland trees are almost always kept close to the house, together with other vegetation protecting the entrance and windows. These traditional uses of trees should be studied to serve landscape management.

The paper is based on a lecture given in the seminar ‘The forest as a Finnish cultural entity’, held in Helsinki in 1986. The PDF includes a summary in Finnish.

  • Guignard, E-mail: mg@mm.unknown (email)
article id 5316, category Article
Timo Pukkala, Timo Kuuluvainen. (1987). Effect of canopy structure on the diurnal interception of direct solar radiation and photosynthesis in a tree stand. Silva Fennica vol. 21 no. 3 article id 5316. https://doi.org/10.14214/sf.a15473
Keywords: canopy; simulation; shading; crown type; interception; tree ideotype; radiation regime
Abstract | View details | Full text in PDF | Author Info

The utilization of direct radiation was studied in five model stands of Poisson-type tree distribution and cone-shaped crowns. The radiation extinction depended on the self-shading of the crown and the shading caused by other trees. The results indicate that at low sun elevation a stand populated by very narrow-crowned trees is most effective in light interception and photosynthesis. At high sun elevation a broad-crowned canopy is best illuminated and most favourable for photosynthesis. A stand with a two-storey canopy is effective in all latitudes when the crowns are moderately narrow. In two-storey canopies the foliage of the lower storey can be better illuminated than in the lower parts of the upper storey, because of the smaller self-shading in the small crowns of the lower storey. A canopy where the crown volume is concentrated on few big crowns is less effective than a canopy consisting of many small crowns.

The PDF includes an abstract in Finnish.

  • Pukkala, E-mail: tp@mm.unknown (email)
  • Kuuluvainen, E-mail: tk@mm.unknown
article id 5310, category Article
Petri Kärenlampi. (1987). Puun lahonkestävyys ja kosteusdynamiikka. Silva Fennica vol. 21 no. 2 article id 5310. https://doi.org/10.14214/sf.a15467
English title: The decay resistance and moisture dynamics of wood.
Original keywords: puulajit; kosteus; sydänpuu; puuaines; lahonkestävyys; mantopuu
English keywords: Pinus sylvestris; Picea abies; sapwood; tree species; heartwood; decay resistance; moisture
Abstract | View details | Full text in PDF | Author Info

In laboratory studies the heartwood content seems to be the only natural property of a wood of different tree species influencing the decay resistance. Moistening and drying by diffusion happen quite slowly. Scots pine (Pinus sylvestris L.) sapwood takes moisture by capillary action quicker than pine heartwood and Norway spruce (Picea abies (L.) H. Karst.) wood. Swelling and shrinkage are also greatest in pine sapwood. Impregnation of pine sapwood can give it better hydrophobic and dimensional stability than that of pine heartwood.

The PDF includes an abstract in English.

  • Kärenlampi, E-mail: pk@mm.unknown (email)
article id 5306, category Article
Timo Pukkala, Taneli Kolström. (1987). Competition indices and the prediction of radial growth in Scots pine. Silva Fennica vol. 21 no. 1 article id 5306. https://doi.org/10.14214/sf.a15463
Keywords: Pinus sylvestris; stand characteristics; simulation; tree growth; competition; radial growth
Abstract | View details | Full text in PDF | Author Info

The effect of competition on the radial growth of Scots pine (Pinus sylvestris L.) was studied in three naturally regenerated stands located in North Karelia, Finland. The competition situation of an individual tree was described with various competition indices which depended on the sizes and distances from the neighbouring trees. One competition index explained about 50% of the variation in 5-year radial growth in one stand. If all stands were combined, one index explained 43.5%, two indices 48.9% and three indices 51.2% of the variation. In one stand, the best competition indices accounted for about 20% of that variation which could not be explained by tree diameter. If all three stands were combined, the best index explained 11% of the residual variation. About 40% of the variation in 5-year radial growth could not be explained by the diameter and competition indices.
The PDF includes an abstract in Finnish.

  • Pukkala, E-mail: tp@mm.unknown (email)
  • Kolström, E-mail: tk@mm.unknown
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 5256, category Article
Outi Muona, Raimo Hiltunen, Erkki Morén, D. V. Shaw. (1986). Analysis of monoterpene variation in natural stands and plustrees of Pinus sylvestris in Finland. Silva Fennica vol. 20 no. 1 article id 5256. https://doi.org/10.14214/sf.a15435
Original keywords: mänty; alkuperä; pluspuut; monoterpeenit; luonnonpopulaatiot
English keywords: Scots pine; progeny; plus trees; monoterpenes; geographical variation
Abstract | View details | Full text in PDF | Author Info

Variation of monoterpene composition of Pinus sylvestris L. was studied in Southern, Central and Northern Finland using data from both natural stands and plus trees. The natural stands were analysed using different techniques and for fewer terpenes than the plus trees.

There were large differences between areas in the proportion of 3-carene in trees from natural stands, as has been discussed by previous authors. The proportion of 3-carene is bimodally distributed and believed to be controlled by a single gene with large effect. For this reason, we stratified our samples into high carene (>10%) and low carene (<10%) groups. Univariate analysis did not reveal any additional differences between natural populations in different zones for components other than 3-carene. In plus trees, several components showed significant differences, but the proportion of 3-carene did not differ between areas. Multivariate discrimination analysis did not distinguish between areas for natural stands. However, for the plus trees discriminant analysis allowed us to discriminate between the zones relatively efficiently. The proportion of correct classification was greater than 64% using the best methods. The central zone was most distinct, and 80% of its trees were correctly classified. Broad generalizations are not possible due to the limitations imposed by our data. Our analysis of phenotypic variation does not support the suggestion that plus trees selected from the north represent a southern type.

The PDF includes an abstract in Finnish.

  • Muona, E-mail: om@mm.unknown (email)
  • Hiltunen, E-mail: rh@mm.unknown
  • Morén, E-mail: em@mm.unknown
  • Shaw, E-mail: ds@mm.unknown
article id 5239, category Article
Jussi Kuusipalo. (1985). On the use of tree stand parameters in estimating light conditions below the canopy. Silva Fennica vol. 19 no. 2 article id 5239. https://doi.org/10.14214/sf.a15418
Keywords: Pinus sylvestris; basal area; Picea abies; canopy; tree species composition; light conditions; light climate; number of stems; canopy coverage
Abstract | View details | Full text in PDF | Author Info

Especially in forest vegetation studies, the light climate below the canopy is of great interest. In extensive forest inventories, direct measurement of the light conditions is too time-consuming. Often only the standard tree stand parameters are available. The present study was undertaken with the aim to develop methods for estimation of the light climate on the basis of readily measurable tree stand characteristics. The study material includes 40 sample plots representing different kinds of more or less mature forest stands of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.).

In each forest stand, a set of hemipherical photographs was taken and standard tree stand measurements were performed. A regression approach was applied in order to elaborate linear models for predicting the canopy coverage. The total basal area of the stand explained 63% of variance in the canopy coverage computed from hemipherical photographs. A coefficient representing the relative proportion of Norway spruce in the stand increased the explanatory power into 75%. When either the stand density (stems/unit area) or dominant age of the stand was included into the model, increment of the explanatory power into 80% was achieved. By incorporating both of the preceding predictors, an explanatory power of 85% was reached.

The PDF includes a summary in Finnish.

  • Kuusipalo, E-mail: jk@mm.unknown (email)
article id 5233, category Article
Leo Heikurainen. (1985). Verhopuuston vaikutus kuusitaimikon kehitykseen. Silva Fennica vol. 19 no. 1 article id 5233. https://doi.org/10.14214/sf.a15412
English title: The influence of birch nurse crop (Betula pubescens) on the growth of Norway spruce (Picea abies) seedling stands on drained peatlands.
Original keywords: kuusi; metsänhoito; kasvu; ojitetut suot; suojapuusto; pakkasvauriot; hieskoivu; verhopuusto; verhopuuston tiheys; verhopuuston poisto
English keywords: forest management; Norway spruce; Picea abies; Betula pubescens; tree growth; frost damages; nurse stand
Abstract | View details | Full text in PDF | Author Info

Young Norway spruce (Picea abies (L.) H. Karst.) are susceptible to early summer frost damage. Birch (Betula pubescens Ehrh.) naturally colonize rich or fairly rich drained peatlands after clear cutting, and can provide protection for developing seedlings. The report describes the development of spruce stands after various types of handing of the birch nurse crops.

Different proportions of birch and spruces did not have any influence on the spruce stand production. In cases where the nurse crop stand is removed when the spruce stand age was 20 years and height 4 m the spruce suffered badly but recovered with time, reaching the spruce stand growing under a nurse stand within the next 20 years. The height growth of spruce depends on the density of the nurse stand, especially on fertile sites. The development of diameter growth also depends on the density of the nurse trees. Removal of the nurse stand in spruce stands on the sites concerned should be done when the spruce stand is 20 years old and at the height of 4 m.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@mm.unknown (email)
article id 5204, category Article
Pirkko Velling, P. M. A. Tigerstedt. (1984). Harvest index in a progeny test of Scots pine with reference to the model of selection. Silva Fennica vol. 18 no. 1 article id 5204. https://doi.org/10.14214/sf.a15383
Keywords: Pinus sylvestris; yield; Scots pine; tree breeding; heritability; harvest index; progeny test
Abstract | View details | Full text in PDF | Author Info

Harvest index and number of associated traits were measured in a 16-year-old Scots pine (Pinus sylvestris L.) progeny test based on full-sib families. It was found that harvest index is a highly heritable trait and that a number of yield components are positively correlated with it. It is suggested that harvest index and tree ideotypes should be the basis of selection in cultivated trees. It is emphasized that an integrated approach to tree improvement including silviculture, soil science, industrial and economic constraints and tree breeding is a prerequisite for maximal response.

The PDF includes a summary in Finnish.

  • Velling, E-mail: pv@mm.unknown (email)
  • Tigerstedt, E-mail: pt@mm.unknown
article id 5201, category Article
Jussi Kuusipalo. (1983). Distribution of vegetation on mesic forest sites in relation to some characteristics of the tree stand and soil fertility. Silva Fennica vol. 17 no. 4 article id 5201. https://doi.org/10.14214/sf.a15184
Keywords: Finland; ground vegetation; indicator species; fertility; forest types; forest site classification; TWINSPAN; Oxalis-Myrtillus type; Myrtillus type; tree stand characteristics
Abstract | View details | Full text in PDF | Author Info

Vegetation data collected from a random sample of mature forest stands representing mesic upland forest sites in Southern Finland were analysed and classified using two-way indicator species analysis (TWINSPAN). The variation of some characteristics of the tree stand and soil fertility between the produced vegetation units were analysed statistically.

Both the species list and the sample list arranged by TWINSPAN reflects the overall site fertility considerably well. The results are in agreement with the main division of mesic forest sites in the Finnish forest site type classification: vegetation units which can be assigned to the Oxalis-Myrtillus site type are clearly separated from the remaining units, and the overall site fertility indicates a statistically significant difference. The within-type variation in the vegetation composition in the Oxalis-Myrtillus site type reflects the variation in site fertility, whereas the within-type variation in the Myrtillus site type is mainly caused by the tree stand factor.

The PDF includes a summary in Finnish.

  • Kuusipalo, E-mail: jk@mm.unknown (email)
article id 5200, category Article
Seppo Kellomäki, Timo Nevalainen. (1983). Näkökohtia puuston tiheyden ja puiden koon välisestä suhteesta. Silva Fennica vol. 17 no. 4 article id 5200. https://doi.org/10.14214/sf.a15183
English title: Relationship between stand density on tree size.
Original keywords: kilpailu; metsikön tiheys; puiden koko
English keywords: tree size; modelling; stand density; within-stand competition
Abstract | View details | Full text in PDF | Author Info

Two Japanese models regarding the within-stand competition have been reviewed on the basis of relevant literature. Competition-density and 3/2 th power models seem to be applicable also into tree stands. The latter model has been applied into the material obtained from literature. Computations showed consistancy with the results obtained elsewhere in the world. It is concluded that also in Finnish conditions the 3/2 th power law may have great potentials in describing the effects of stand density on tree size.

The PDF includes a summary in English.

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

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

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

  • Tigerstedt, E-mail:
article id 5140, category Article
Lars Westman. (1981). Monitoring of coniferous forest ecosystems in Sweden. Silva Fennica vol. 15 no. 4 article id 5140. https://doi.org/10.14214/sf.a15367
Keywords: soil respiration; conifers; tree growth; acidification; Sweden; air pollution; monitoring programme; acid compounds; heavy metals; bioindicators; phosphatase activity
Abstract | View details | Full text in PDF | Author Info

A monitoring program is planned for the terrestrial environment around industries in Sweden, which emit acid compounds and heavy metals. Directions for the County Government Boards are being prepared. The paper deals with the present pollution situation in Sweden, based on recent scientific results, the justifications for local monitoring, and the organizing of the monitoring including the parameters suggested.

Four examples from a case study at an oil power station illustrate reporting of the data and the difficulties in interpreting the results. The examples are the distribution of a lichen indicator, heavy metal content and phosphatase activity in the moor layer, soil respiration and tree growth.

  • Westman, E-mail: lw@mm.unknown (email)
article id 5133, category Article
F. Scholz. (1981). Genecological aspects of air pollution effects on northern forests. Silva Fennica vol. 15 no. 4 article id 5133. https://doi.org/10.14214/sf.a15360
Keywords: stress; air pollution; ecological niche; forest trees; environmental conditions; reduced resistance; low temperatures
Abstract | View details | Full text in PDF | Author Info

Natural forest tree populations are adapted to their natural environment. Forest tree species under northern conditions are at the edge of their range where the short growing season and the low winter temperatures are the two main factors limiting their ecological niche. Effects of air pollution on the ecological niche, designated as the environmental conditions that permit a population to survive permanently, are discussed according to G.E. Hutchinson’s concept of the ecological niche. Air pollution as an additional stress factor influences the ecological niche either by the direct influence as an additional dimension of the ecological niche or by interaction with the other dimensions. These interactions are especially important for low level long-term effects of air pollution which can result in reduced resistance to low winter temperature or, due to reduced net assimilation, reduced capability to survive the long period of winter dormancy. These effects influence the boundary of the ecological niche and reduce the area of the biotope of the respective species.

Within the remaining biotope genetic changes in forest tree species take place. Due to individual differences in exposure and susceptibility of trees to air pollution, higher and therefore more exposed trees as well as more susceptible trees will be reduced in reproduction or even be eliminated. This causes genetic changes in the tree population.

  • Scholz, E-mail: fs@mm.unknown (email)
article id 5114, category Article
Matti Kärkkäinen. (1981). Haapa- ja poppelilajien (Populus) käyttö. Silva Fennica vol. 15 no. 2 article id 5114. https://doi.org/10.14214/sf.a15055
English title: Utilization of aspen and poplars (genus Populus).
Original keywords: viljely; puulajit; haapa; poppelit; käyttö
English keywords: Populus tremula; tree species; cultivation; poplars; aspen; utilization
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to establish from the literature the purposes and for which aspen (Populus tremula L.) and related poplar species are used and can be used.  According to the literature, numerous Populus species can be utilized in the industry with success instead of light softwood species in addition to them. The main emphasis is in the growing of large-sized timber, and there is no clear trend to changing to the short-rotation forestry of poplar. However, the utilization of the good sprouting properties of Populus species will probably increase as this regeneration method is cheap.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 5078, category Article
Seppo Kellomäki, Pertti Hari. (1980). Eco-physiological studies on young Scots pine stands. I. Tree class as indicator of needle biomass, illumination and photosynthetic capacity of crown system. Silva Fennica vol. 14 no. 3 article id 5078. https://doi.org/10.14214/sf.a15019
Keywords: Pinus sylvestris; Scots pine; canopy; photosynthetic capacity; needle biomass; tree class
Abstract | View details | Full text in PDF | Author Info

The concept of tree class as indicated by dominant, codominant, intermediate and suppressed trees is analysed using empirical material representing 13 younger Scots pine (Pinus sylvestris L.) stands. The relative needle biomass, i.e. the needle biomass related to the maximum needle biomass in the stand, was closely related to the relative height of the tree and independent of the stand characteristics. Furthermore, the relative illumination of the crown system was related to the relative height of the trees as well as the relative photosynthetic capacity and tree-to-tree variation in growth. When calculated per needle biomass unit it appeared that height growth, radial growth, needle growth and other growth parameters were the highest in the suppressed trees. The suppressed trees thus appear to be more efficient in utilizing available resources than other tree classes. The ecologic significance of the results is discussed.

The PDF includes a summary in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
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 5062, category Article
I. Etverk. (1980). Geographical variability of the Norway spruce in the Estonian SSR. Silva Fennica vol. 14 no. 1 article id 5062. https://doi.org/10.14214/sf.a15003
Keywords: Norway spruce; Picea abies; tree breeding; Estonia; provenience; Symposiums; Soviet Union; geographic variation
Abstract | View details | Full text in PDF | Author Info

The productivity and several morphological features of Estonian Norway spruce (Picea abies L. Karst.) show significant geographical variation. This is no doubt because of differences in the climatic and soil conditions, which in spite of the small area of the country is quite large. In order to check the possible geographical variability of the gene pool, preliminary experiments were carried out in 1969, when seeds from 93 spruce stands originating from 14 forest enterprises were sowed in a nursery. After two years, the seedlings originating from south-eastern Estonia were the tallest. The seedlings from northern origins were smallest. However, it cannot be maintained that spruces from Southern Estonia are of better genotype than genotype from Northern Estonia since the genotypes are evaluated on the basis of ecological conditions under which the experiments are carried out. Another study suggests that an average shift of 7° to the east of the territory for spruces are suitable for cultivation in Estonia.

The PDF includes a summary in Finnish.

  • Etverk, E-mail: ie@mm.unknown (email)
article id 5061, category Article
Max Hagman. (1980). Experiences with Norway spruce provenances in Finland. Silva Fennica vol. 14 no. 1 article id 5061. https://doi.org/10.14214/sf.a15002
Keywords: Norway spruce; Picea abies; tree breeding; Finland; Symposiums; provenience breeding
Abstract | View details | Full text in PDF | Author Info

Ecological investigations have shown that Norway spruce (Picea abies (L.) H. Karst.) reached Western Finland about 1,500–1,000 years B.C. and did not reach Åland islands before around the year 0. The species spread into Finland from the east and north-east, having survived the glaciation somewhere in the central parts of the Asian continent. Geographical variation has provided foresters with provenances of better growth and higher economic yield. In Finland, provenances, for instance, from Austria, Eastern Germany, Romania, Southern Poland and Slovakia have been planted in experiments, mostly in various parts of Southern Finland. According to the results of the experiments, it seems that for the more northern parts of Finland and Sweden the best material was to be obtained from north-east Europe.

The Scandinavian countries decided in 1975 to make a common assessment of all the provenance experiments with Norway spruce. The synthesis confirms the earlier view that provenances from the most north-eastern parts of Central Europe are of the greatest value for Finland.

The PDF includes a summary in Finnish.

  • Hagman, E-mail: mh@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 5059, category Article
Pertti Harstela. (1980). Jäljelle jäävä puusto ja ajouralta toimivat harvennuspuun korjuukoneet. Silva Fennica vol. 14 no. 1 article id 5059. https://doi.org/10.14214/sf.a15000
English title: Remaining trees and machines working from the strip roads in thinning.
Original keywords: harvennushakkuu; puunkorjuu; metsäkoneet; ajourat; jäljelle jäävä puusto; valikoiva harvennus
English keywords: skidding; thinning; timber harvesting; forest machines; strip roads; remaining trees
Abstract | View details | Full text in PDF | Author Info

In the first part of the study the hindrance of the remaining trees when felling trees by machines working from the strip road in selective thinning was studied on the basis of the literature. In the second part there was geometrically studied the need of schematic thinning in some type stands when bundles are pre-skidded straight-lined to the strip road. In average only 0-1 trees per pre-skidding trail needs to be removed. It was concluded that trees removed from the pre-skidding trail do not significantly increase the need of schematic thinning. Remaining trees do not limit the length of machine booms if the pre-skidding trails are planned during the felling.

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  • Harstela, E-mail: ph@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).

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  • Hagman, E-mail: mh@mm.unknown (email)
article id 5052, category Article
Markku Nylund, Antti Haapanen, Seppo Kellomäki, Liisa Nylund. (1979). Deterioration of forest ground vegetation and decrease of radial growth of trees on camping sites. Silva Fennica vol. 13 no. 4 article id 5052. https://doi.org/10.14214/sf.a14909
Keywords: tree growth; ground vegetation; trampling; campsite; grass
Abstract | View details | Full text in PDF | Author Info

The ground cover vegetation and tree growth at several camping sites in Southern Finland were investigated. The deterioration of ground vegetation appeared to be unavoidable in these areas, and only a few grass species were tolerant to heavy trampling. Only moderate deterioration was, however, detected when the trampling level was lower than 10,00015,000 user days. On the other hand, the ground cover was completely destroyed when the trampling level exceeded 100,000 user days. A considerable decrease in radial growth appeared to be associated with destruction of the ground vegetation. The decrease was abrupt and was found to continue throughout the whole period of use. After ten years’ use the growth in the trampled areas was 35% lower than that that of the untrampled areas. A further decrease in radial growth is expected in the future. 

The PDF includes a summary in Finnish. 

  • Nylund, E-mail: mn@mm.unknown (email)
  • Haapanen, E-mail: ah@mm.unknown
  • Kellomäki, E-mail: sk@mm.unknown
  • Nylund, E-mail: ln@mm.unknown
article id 5006, category Article
Seppo Kellomäki. (1978). Typpilannoituksen vaikutus havupuiden fotosynteesikapasiteettiin. Silva Fennica vol. 12 no. 3 article id 5006. https://doi.org/10.14214/sf.a14860
English title: Effects of nitrogen fertilization on photosynthetic capacity of coniferous trees.
Original keywords: havupuut; lannoitus; typpilannoitus; fotosynteesikapasiteetti; neulasmassa
English keywords: biomass; photosynthetic capacity; nitrogen fertilization; coniferous trees; needle mass
Abstract | View details | Full text in PDF | Author Info

The effect of nitrogen fertilizers on the photosynthetic capacity of conifers is assessed on the basis of literature. The review emphasizes the role of changes of needle mass as a factor affecting the result of nutrient application. In particular, the increase in needle mass results in a considerable increase in photosynthetic capacity. The effect of fertilization on the photosynthetic rate seems to be of minor importance. The effect on the photosynthetic rate is, however, poorly documented as is the case for the effect of fertilization on the respiration rate. There is evidence that proper application of nitrogen fertilizers may double the photosynthetic capacity of conifers, mainly as a result of increase in needle mass.

The PDF includes a summary in English.

  • Kellomäki, E-mail: sk@mm.unknown (email)
article id 4970, category Article
Markku Mäkelä. (1977). Metsähakkeen tiheyden laskeminen. Silva Fennica vol. 11 no. 2 article id 4970. https://doi.org/10.14214/sf.a14821
English title: Calculating the basic density of whole tree- and logging residue chips.
Original keywords: kuusi; tiheys; mänty; koivu; hake; metsähake; kokopuuhake; leppä
English keywords: Norway spruce; birch; Scots pine; basic density; alder; wood chips; logging residue; whole tree chips
Abstract | View details | Full text in PDF | Author Info

A method is presented in this study for calculating the basic density of whole tree- and logging residue chips and the results of trial measurements on some commonly used chip sorts. The basic density of Scots pine whole tree chips was found to be 1–18 kg/m3 smaller than that of pine pulpwood of the same age. The basic density of Norway spruce whole tree chips was 4–22 kg/m3 greater than that of similar aged pulpwood. The basic density of birch whole tree chips was 4–16 kg/m3 and grey alder whole tree chips 7–24 kg/m3 greater than pulpwood of the same age. The basic density of conifer logging residue chips was considerably greater than that of pine and spruce whole tree ships.

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  • Mäkelä, E-mail: mm@mm.unknown (email)
article id 4948, category Article
Matti Kärkkäinen. (1976). Puun ja kuoren tiheys ja kosteus sekä kuoren osuus koivun, kuusen ja männyn oksissa. Silva Fennica vol. 10 no. 3 article id 4948. https://doi.org/10.14214/sf.a14794
English title: Density and moisture content of wood and bark, and bark percentage in the branches of birch, Norway spruce and Scots pine.
Original keywords: kuusi; mänty; koivu; kosteus; kokopuuhaketus; oksat; kuori
English keywords: Norway spruce; birch; Scots pine; moisture content; bark; density; branches; total tree chipping
Abstract | View details | Full text in PDF | Author Info

In the study the proportion of branch samples of various diameter were studied. The branches were taken from small trees to be harvested by total tree chipping method. The material consisted of 1,056 branch samples of birch (Betula verrucosa, now B. pendula Roth, and Betula pubescens Erhr.), Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) at intervals of 20 cm along each branch.

With exception of the basic density of bark, there was a relation between all the other properties which were studied and the diameter. Even when the effect of diameter was eliminated, in many cases the effect of the distance of the samples from the stem became apparent.

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  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4944, category Article
Eino Mälkönen. (1976). Effect of whole-tree harvesting on soil fertility. Silva Fennica vol. 10 no. 3 article id 4944. https://doi.org/10.14214/sf.a14790
Keywords: logging; thinnings; nutrient losses; whole-tree harvesting
Abstract | View details | Full text in PDF | Author Info

This paper analyses the nutrient loses caused by whole-tree harvesting on the basis of the literature data. It has been considered that traditional stemwood harvesting does not lead to impoverishment of the soil because the nutrient content of the wood is quite low. The nutrient loss occurring in connection with heavy thinnings and whole-tree harvesting has been considered so great that it has to be compensated by fertilizer application. In comparison with harvesting unbarked stem timber, whole-tree harvesting has been found to increase the nutrient loss at the stage of final cutting as follows: N2 to 4 times, P 2 to 5 times, K 1.5 to 3.5 times and Ca 1.5 to 2.5 times. Depending on the conditions prevailing on the site, any one of these nutrients may be the limiting factor for tree growth during the next tree generation

The PDF includes a summary in Finnish.

  • Mälkönen, E-mail: em@mm.unknown (email)
article id 4931, category Article
Olli Makkonen. (1976). Mitä vanhalla ajalla tiedettiin puiden kasvusta. Silva Fennica vol. 10 no. 1 article id 4931. https://doi.org/10.14214/sf.a14773
English title: What was known in ancient times about growth of trees?
Original keywords: historia; puiden kasvu
English keywords: history; growth of trees
Abstract | View details | Full text in PDF | Author Info

In this article, information about tree growth which was familiar to the learned men in the old days is presented. The time when different tree species start growing, the different growth rate of various tree species, the age of trees, their resistance to injury etc. are discussed.

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  • Makkonen, E-mail: om@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 4924, category Article
Teklé Kapustinskaité. (1975). Puuston kasvu ja turpeen tuhkapitoisuus ojitetuilla soilla. Silva Fennica vol. 9 no. 3 article id 4924. https://doi.org/10.14214/sf.a14766
English title: Ash content of peatland soils and stand growth in connection with drainage.
Original keywords: kuusi; mänty; ravinteisuus; puulajit; turvemaat; ojitetut suot; pituuskasvu; rauduskoivu; tervaleppä; Liettua; tuhkapitoisuus; hieskoivu; metsäsaarni
English keywords: Pinus sylvestris; Norway spruce; birch; Betula pendula; Picea abies; Betula pubescens; drained peatlands; Scots pine; height growth; tree species; Alnus glutinosa; alder; ash content; fertility; Fraxinus exelsior; ash; Lithuania
Abstract | View details | Full text in PDF | Author Info

The ash content has been found to correlate with the fertility of peatlands. Relationship between height of 80-year-old stands and ash content of peat in topmost 30 cm layer was examined in Lithuanian conditions. On drained peatlands with ash content of peat from 3% to 8% pine stands increase in height. Ash content of peat being about 7% Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) stands on drained sites are found to be of equal height. Ash content of peat more than 8–9% has no significant effect on growth of pine or spruce stands. Birch (Betula verrucosa (B. Pendula Roth.) and Betula pubescens Erhrh.), stands are less sensitive to ash content of peat compared with other species. Black alder (Alnus glutinosa L. Gaertn.) stands occurred in sites with ash content of peat more than 8–10%. The height of the stands become equal both in drained and undrained sites in the cases where ash content of peat is about 16–18%. Ash (Fraxinus exelsior L.) stands attain high productivity on drained sites with ash content of peat about 20%.

The PDF includes a summary in English.

  • Kapustinskaité, E-mail: tk@mm.unknown (email)
article id 4897, category Article
A. V. Chudnyi. (1974). Metsäpuiden populaatiorakenteen tutkimusmenetelmistä. Silva Fennica vol. 8 no. 1 article id 4897. https://doi.org/10.14214/sf.a14741
English title: Investigation methods in forest tree population studies.
Original keywords: mänty; metsänjalostus; taudinkestävyys; männyntyvitervastauti; Neuvostoliitto; terpeenit
English keywords: Pinus sylvestris; Scots pine; tree breeding; Heterobasidion annosum; disease resistance; terpenes; Soviet Union
Abstract | View details | Full text in PDF | Author Info

From the tree breeder’s point of view, an investigation of the chemical compounds in a tree population is worthwhile, if sufficiently high correlations exist between the chemical composition and any economical important characteristics. In Scots pine (Pinus sylvestris L.) populations, such a correlation seems to exist between a high α-pinene and a low Δ3-carene content on the one hand, and the poor resistance to Fomitopsis annosa Fr. (now Heterobasidion annosum (Fr.) Bref.) but a rapid development during the first half of the life cycle on the other hand. Detailed investigation on the terpene contents in pine populations were conducted at 121 locations throughout the Soviet Union. As a result, the range of this species was divided into zones, each of which was characterized by a distinct terpene composition pattern. In continuing selection and breeding work, the terpene contents are being used as indicators when the variation of economically important characteristics of Scots pine populations is studied.

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

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

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  • Luukkanen, E-mail: ol@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.

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  • Laatikainen, E-mail: pl@mm.unknown (email)
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 4865, category Article
Tauno Kallio. (1972). Esimerkki kuusikon lahovikaisuuden Etelä-Suomessa aiheuttamasta taloudellisesta menetyksestä. Silva Fennica vol. 6 no. 2 article id 4865. https://doi.org/10.14214/sf.a14668
English title: An example on the economic loss caused by decay in growing Norway spruce timber in Southern Finland.
Original keywords: kuusi; laho; taloudellinen menetys; kustannus; lahopuu
English keywords: Norway spruce; Picea abies; decay; economic loss; rotten trees
Abstract | View details | Full text in PDF | Author Info

A growing stand of Norway spruce (Picea abies (L.) H. Karst.) marked for cutting was investigated in the winter of 1971–72 in Helsinki in Southern Finland in order to determine the economic loss caused by decay. Taking a sample from growing spruce trees with increment borer is not a reliable method of determining the frequency of decay. The decayed stems were twice measured for assortment cutting into lengths; the first time disregarding the decay and the second time doing the actual assortment cutting according to the grade of timber. The direct economic loss caused by decay was 13% of the price for standing timber. The indirect loss may be as great as the direct loss.

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  • Kallio, E-mail: tk@mm.unknown (email)
article id 4836, category Article
Erkki Lähde. (1971). Anaerobisten olosuhteiden ja aerobisuusrajan esiintymisestä erilaisilla luonnontilaisilla turvemailla ja merkityksestä suotyypin kuvaajana. Silva Fennica vol. 5 no. 1 article id 4836. https://doi.org/10.14214/sf.a14625
English title: Anaerobic conditions in various virgin peat soils and the significance of the aerobic limit as an indicator of site quality.
Original keywords: suotyypit; turvemaat; luonnontilaiset suot; anaerobisuusraja; puuston kasvu; pohjaveden syvyys
English keywords: Finland; tree growth; virgin peatlands; peatland types; aerobic limit; ground water table
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to increase the knowledge of the anaerobic conditions prevailing in virgin peat soils of different kinds, and on the fluctuation of the aerobic limit. Silver rod method was used to indicate anaerobic conditions and to locate the aerobic limit. The material included 18 peatland sample plots on treeless bogs, in pine bogs and in spruce swamps in Southern Finland. Observations of the discoloration of the silver rods and measurements of ground water level were made from 8 June to 13 August 1968.

The results show that the location of the aerobic limit is dependent of the depth of the ground water table, and usually lies 5–15 cm above the ground water table. Down to 10–20 cm below the aerobic limit, where it reaches maximum, the rate of decomposition of sulfurous organic matter is positively correlated with the distance from the aerobic limit. Deeper it gradually decreases, and in the depth of 25–35 cm no hydrogen sulphide seems to be released.

In the forested peatland types the volume of the growing stock and the increment were dependent on the depth of the aerobic limit only when nutrient content and pH of the peat was more or less constant. Where the aerobic limit was close to the ground surface but the nutrient contents were relatively high, the volume of the growing stock may be comparatively high. Birch (Betula sp.), better than the conifers, is able to stand conditions poor in oxygen. The growing stock was poor in sites where the aerobic limit was near the ground surface, but the nitrogen and phosphorus contents were high, or vice versa. Consequently, aerobic limit is of great importance as an indicator of site quality.

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  • Lähde, E-mail: el@mm.unknown (email)
article id 4833, category Article
Eero Malmivaara, Jouni Mikola, Christel Palmberg. (1971). Pajujen mahdollisuudet metsäpuiden jalostuksessa. Silva Fennica vol. 5 no. 1 article id 4833. https://doi.org/10.14214/sf.a14622
English title: Potential of willows in forest tree breeding.
Original keywords: metsänjalostus; Suomi; pajut
English keywords: Finland; forest tree breeding; willows; Salix
Abstract | View details | Full text in PDF | Author Info

A review is made into the experiences and possibilities of willow breeding, with a particular consideration of their application under Finnish conditions.

In comparison with other tree genera, Salix has many advantages in breeding. The great number of species, large genetic variation between and within species and frequent crossability offer good possibilities for improvement by hybridization. The dioecious flowering, plentiful seed production and short generation cycle are valuable properties for breeding by controlled pollination. Individuals with desirable characteristics can be easily propagated vegetatively from cuttings. The propertied stated above are also characteristic of poplars, the breeding of which has resulted in great success. Corresponding results can be therefore expected from willow breeding, which has recently been initiated in several countries.

Today willows have no practical significance for forestry in Finland. There are, however, some suitable Salix species, both indigenous and exotic, for starting material for breeding, and plenty of favourable sites for willows. Therefore, the beginning of breeding research with willows should be well justified also in Finland.

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  • Malmivaara, E-mail: em@mm.unknown (email)
  • Mikola, E-mail: jm@mm.unknown
  • Palmberg, E-mail: cp@mm.unknown
article id 4831, category Article
Lauri Mikkola. (1970). Kuusilajien risteytyvyydestä. Silva Fennica vol. 4 no. 4 article id 4831. https://doi.org/10.14214/sf.a14620
English title: On the crossability of Picea species.
Original keywords: mänty; metsänjalostus; itävyys; kuuset; risteytys; risteytyskokeet; keinollinen pölytys
English keywords: Pinus sylvestris; Picea abies; tree breeding; Picea; Abies; controlled pollination; interspecific sterility; hybrids; crossbreeding
Abstract | View details | Full text in PDF | Author Info

Seed development was microscopically studied after controlled pollinations. In all the interspecific crosses incompatibility occured. In the following crosses the growth of all the pollen tubes stopped before they had penetrated through the nuclear cap: Picea abies (L.) Karst. x mariana, abies x jezoensis (and the reciprocal), abies x omorika (and the reciprocal), mariana x asperata, mariana x jezoensis and Picea abies x Pinus sylvestris L.

Some of the eggs were fertilized in the crosses Picea abies x glauca (and the reciprocal) abies x asperata, abies x koyamai, abies x obovata, mariana x omorika and jezoensis x omorika. Embryo degeneration was observed in all these crosses. All the embryos died in the crosses abies x glauca (and the reciprocal) as well as jezoensis x omorika. Adequate amounts of full seed for germination test was obtained from the crosses abies x asperata, abies x koyamai and abies x obovata. In all these crosses there were seeds which were able to germinate and the hybrids are now one growth season old.

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  • Mikkola, E-mail: lm@mm.unknown (email)
article id 4823, category Article
Christel Palmberg. (1970). Heritabiliteetin arvioiminen eräässä männyn (Pinus silvestris L.) jälkeläiskokeessa. Silva Fennica vol. 4 no. 3 article id 4823. https://doi.org/10.14214/sf.a14612
English title: Estimation of heritability in open-pollinated plus tree progenies of Pinus sylvestris L.
Original keywords: mänty; oksikkuus; metsänjalostus; pluspuut; pituuskasvu; perinnöllisyys
English keywords: Pinus sylvestris; Scots pine; height growth; tree breeding; heritability; branchiness; plus trees
Abstract | View details | Full text in PDF | Author Info

Field experiments of Scots pine (Pinus sylvestris L.) was established by planting seedlings grown from seeds collected from open-pollinated plus trees throughout the country. The 36 progenies represented were planted in 4 blocks as 2+2 transplants in 1960. The main characteristics of the seedlings were measured in 1966 and 1968. Considerable damage had been caused to the stands by moose (Alces alces) and Melampsora pinitorqua Rostr., consequently, therefore, only normally developed seedlings were measured.

Highly significant differences between progenies were found in the number of branches in 1968 and in the ratio of height of tree to the length of the longest branch. In 1968, the differences in height between progenies were not significant, but there were significant differences between blocks both in tree height and length of terminal shoot. Obviously, the edaphic heterogeneity of the site has influenced mainly the juvenile growth of the plants, because in the length of the terminal shoot there could be seen also significant differences between the progenies. There were no significant differences between the progenies in the length of the longest branch, in the angles of the thickest branches, in stem taper and in the diameter of the thickest branch.

The PDF includes a summary in English.

  • Palmberg, E-mail: cp@mm.unknown (email)
article id 4819, category Article
Matti Kärkkäinen. (1970). Hakkuutähteiden merkityksestä puuston vaurioitumisen ja raiteenmuodostuksen kannalta harvennusmetsissä. Silva Fennica vol. 4 no. 2 article id 4819. https://doi.org/10.14214/sf.a14608
English title: Significance of logging waste in thinnings as to scars and tracks in the terrain.
Original keywords: maaperä; harvennushakkuu; puunkorjuu; metsäkuljetus; hakkuutähteet; metsäkoneet; maastovauriot; puustovauriot; ajourat; kantavuus
English keywords: thinnings; forest haulage; soil; timber harvesting; terrain transportation; strip roads; logging waste; tree injuries; stem injuries; tracks; carrying capacity
Abstract | View details | Full text in PDF | Author Info

The purpose of this study was to explain whether it is possible to affect, in practical working site conditions, by means of logging waste on the strip road, the depth of the track which is formed in terrain transportation and the injuries of the growing stand. Five 20 m long investigation areas with logging waste and five similar areas without logging waste were arranged on one strip road at Teisko logging site in Southern Finland. The logging waste layer was mainly Norway spruce and 10–15 cm thick. A KL–836 B forwarder was used. The type of soil was loam.

The logging waste affected the depth of the track only by decreasing the wear of humus layer. Even decreasing effect of logging waste on the injuries in the growing stand was minor. At Kitee working site in Eastern Finland strip roads were studied. The type of soil was thick, rather mouldered peat. The thickness of logging waste was 3–4 times greater than in Teisko, mainly spruce. A Volvo Nalle SM 460 forwarder was used. The effect of the logging waste on the depth of the tracks was clearly to be noticed. On basis of the appearance of the tracks one could assume that the difference was due to different wear of the humus, and not so much due to the quantity of logging waste that improves the carrying capacity of terrain.

In some extent logging waste was also found to affect the amount and quality of tree injuries. In practical working conditions, the importance might be small, since in the experiments an unrealistically great amount of logging waste was used.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
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 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 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 4761, category Article
Pentti Nisula. (1968). Ehdotus metsikön kuution ja käyttöpuuosuuden määrittämiseksi. Silva Fennica vol. 2 no. 1 article id 4761. https://doi.org/10.14214/sf.a14545
English title: A proposal for the determination of total volume and utilization per cent of standing timber .
Original keywords: menetelmät; kuutiomäärä; puuston tilavuus; käyttöpuun määrä; hylkypuun määrä; puun tilavuus
English keywords: volume; stand volume; timber measurement; methods; volume of a tree
Abstract | View details | Full text in PDF | Author Info

The present study gives an account of the dependence prevailing between the actual volume of timber crops, and, on one hand, the sum of cylindrical volume of individual trees, and on the other hand, the utilization per cent. This dependence is rectlinear if the volumes in question are calculated on a running-foot basis. The cylindrical volume of individual trees was calculated on the basis of cross-section area at breast height and the height of the trees. On the basis of the results, it seems that it is possible to simplify timber measurement.

The PDF includes a summary in English.

  • Nisula, E-mail: pn@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 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 4740, category Article
Pentti Räsänen. (1967). Metsänviljelyksessä käytettävien taimien luokitteluperusteet. Silva Fennica vol. 1 no. 1 article id 4740. https://doi.org/10.14214/sf.a14450
English title: Book review: ’Wachstum und Qualität von Forstpflanzen'.
Keywords: book review; tree nurseries
Abstract | View details | Full text in PDF | Author Info

This article is a book review of a book ’Wachstum und Qualität von Forstpflanzen. Zweite Erweitrte Auflage von Die Gütebeurteilung von Forstpflanzen’ written by Helmut Scmidt-Vogt.

  • Räsänen, E-mail: pr@mm.unknown (email)
article id 4732, category Article
Juhani Päivänen. (1966). Sateen jakaantuminen erilaisissa metsiköissä. Silva Fennica no. 119 article id 4732. https://doi.org/10.14214/sf.a14290
English title: Distribution of rainfall in different types of forest stands.
Original keywords: kuusi; mänty; koivu; puulajit; sadanta; metsikkösadanta; runkovalunta
English keywords: Pinus sylvestris; Norway spruce; birch; Betula; Picea abies; Scots pine; tree species; precipitation; throughfall; stem flow
Abstract | View details | Full text in PDF | Author Info

Stand precipitation and stemflow studies became necessary in connection with hydrologic studies, for instance, to explain the deviations resulting from rains in the ratios between the water content of peat and the groundwater level, throughfall during rains of variable heaviness, and effect of stand treatment on soil moisture level. In this project the distribution of rainfall in stands differing in species composition and density was studied in Central Finland in 1963–1965 in fifteen stand precipitation sample plots. In addition, rain gauges were situated under individual Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.) and birch (Betula sp.) trees.

The average precipitation in the open was 4.8 mm, the corresponding precipitation in the stand was 77% for birch, 71% for pine and 62% for spruce. Measurements of stemflow from individual sample trees showed that less than ¼ mm (about 1.5%) during a 15 mm rain in a pine stand. In the spruce stands stemflow is negligible. A part of the sample plots was in drained peatlands with a dense vegetation of small shrubs. The shrub layer retention was about 10% even during heavy rain. In a small forest clearing, the bordering effect of the forest was seen up to the distance of 5 metres from the edge of the forest. During the period of study, on an average 3% more precipitation was recorded in the clearing than in the open, the difference being probably due to the stronger wind effect in the open.

The PDF includes a summary in English.

  • Päivänen, E-mail: jp@mm.unknown (email)
article id 4730, category Article
Erkki Lähde. (1966). Kokeita selluloosan hajaantumisnopeudesta erilaisissa metsiköissä. Silva Fennica no. 119 article id 4730. https://doi.org/10.14214/sf.a14288
English title: Experiments on the decomposition rate of cellulose in different stands.
Original keywords: kuusi; koivu; puulajit; hajotus; maatuminen; selluloosa; hajoaminen; hajotusnopeus
English keywords: Norway spruce; birch; Betula; Picea abies; tree species; decompostition; decomposition rate; cellulose
Abstract | View details | Full text in PDF | Author Info

The aim of this project was to investigate the cellulose decomposition rate in the soil on the ecological conditions created by different tree species, particularly birch (Betula sp.) and Norway spruce (Picea abies (L.) H. Karst.). Therefore, comparable sample plots were established in adjoining birch and spruce stands. Data on the stands, the vegetation, and the soil in the sample plots were collected. The experiment was carried out in the Ruotsinkylä Experimental Forest near Helsinki in Southern Finland.

Five pieces (3x5x0.15 cm) of cellulose (bleached sulphite pulp) were dried, weighed, and fastened in a row into a nylon bag. The bags were placed into the soil at a slant so that the upmost piece of cellulose was in the depth of 0–1.5 cm and the bottom one 6–7.5 cm. The weight losses of the pieces were measured after periods ranging from 6 to 12 months.

The results show that even within the same forest type, decomposition is much more rapid in birch stands than in spruce stands. In all the stands the decomposition rate decreased rapidly with increasing depth. The difference between birch and spruce stand, as well as the decrease with increasing depth, was probably mainly due to different thermal conditions.

The PDF includes a summary in English.

  • Lähde, E-mail: el@mm.unknown (email)
article id 4726, category Article
H. Lyr, G. Hoffmann. (1965). Studies on growth of roots and shoots of certain tree species. Silva Fennica no. 117 article id 4726. https://doi.org/10.14214/sf.a14284
Keywords: birch; larch; pine; tree species; growth; experiments
Abstract | View details | Full text in PDF | Author Info

Understanding the growth of trees is the prerequisite for meaningful forest management. Hence the studies on the ways the trees grow is important. The growth of roots and sprouts was studied by Larix leptolesis, Pinus silvestris, Betula pendula, Robinia pseudoacasia, Populus euramericana, Pseudotsuga taxifolia, Quercus borealis and some other species. The results of still ongoing experiments on pine, birch and larch are presented for root and shoot growth.

The results indicate that the amount of light or shade the tree is having plays an important role in the growth. Hence some tree species are better adapted to shade than others, there are differences in their growth depending whether they are in light or in shade. 

  • Lyr, E-mail: hl@mm.unknown (email)
  • Hoffmann, E-mail: gh@mm.unknown
article id 4704, category Article
V. A. Kolehmainen. (1961). Lehtikuusenviljelys Tuomarniemellä. Silva Fennica no. 108 article id 4704. https://doi.org/10.14214/sf.a9139
English title: Cultivation of larch in Tuomarniemi, Finland.
Original keywords: viljely; Suomi; lehtikuuset; ulkomaiset puulajit; Tuomarniemi
English keywords: larch; Larix; Finland; cultivation; Larix decidua; foreign tree species; Larix sibirica; Larix gmelinii; Larix americana; Larix laricina
Abstract | View details | Full text in PDF | Author Info

Foreign tree species have been planted in Finland since 1900s, the most famous being Larix sibirica plantations in Raivola in Karelia, which now belongs to Soviet Union. One of the largest larch plantations of Finland today is situated in Tuomarniemi, in Central Finland. Ten larch stands were established in Tuomarniemi between 1912 and 1937 mainly by planting. The stand established in 1937 was sown. The trees represent five larch species: Larix sibirica Ledeb. (5 stands), Larix gmelinii var. kurilensis (2 stands, current name probably Larix gmelinii var. gmelinii), Larix americana Michx. (1 stand, now Larix laricina), Larix decidua Mill. (1 stand) and Larix occidentalis Nutt. (1 stand). The total area of the larch stands is 82.5 ha. This paper reports the studies made in the plantations in 1958.

In Tuomarniemi larch grows well in many types of soil from Vaccinium type sites to fresh mineral soil sites. The age of the stands varies from 19 to 48, height from 12 to 24 metres and annual growth from 5 to 12 m3/ha. Larix sibirca has the best stem form of the species, followed by L. gmelinii var. kuriliensis. Easiest to split is the straight-grained L. gmelinii var. kuriliensis. L. sibirica is almost as easy to process. The wood of L. decidua, on the other hand, is often spiral-grained and tough. The trees are seldom infected with decay fungi.

The PDF includes a summary in German.

  • Kolehmainen, E-mail: vk@mm.unknown (email)
article id 4672, category Article
Leo Heikurainen. (1957). Lettoräme ja sen metsäojituskelpoisuus. Silva Fennica no. 93 article id 4672. https://doi.org/10.14214/sf.a9119
English title: Eutrophic pine bogs and their suitability for draining.
Original keywords: ojituskelpoisuus; kasvillisuus; suot; kasvu; suotyyppi; lettoräme
English keywords: vegetation; tree growth; peatlands; peatland type; fen-like pine swamp; drainability of peatlands; swamps
Abstract | View details | Full text in PDF | Author Info

There are about 155,000 ha of fen-like pine swamps (eutrophic pine bogs) in Finland, major part of which are situated in Northern Finland. In the classification system for drainability of peatlands, this type of peatlands had been placed in the first class. The study presents a new evaluation for the peatland type, based on vegetation and tree growth.

According to a previous study, the vegetation of fen-like pine swamps can be characterised by distinctive plant communities that seem to reflect the fertility and high pH of the underlying soil. In this study, the fen-like pine swamps were divided in two subtypes based on the vegetation: proper fen-like pine swamps and fen-like pine swamps with ericaceous shrubs. Both have distinctive vegetation, which is described in the article. The distribution of the subtypes seems to be different: fen-like pine swamps with ericaceous shrubs are more common in eastern parts of Northern Finland. The two subtypes could be divided in different drainability classes according to tree growth, proper fen-like pine swamps belonging to class 1 and fen-like pine swamps with ericaceous shrubs to class 4.

The article includes a summary in English.

  • Heikurainen, E-mail: lh@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 4627, category Article
Paavo Jaakko Ollinmaa. (1952). Jalot lehtipuumme luontaisina ja viljeltyinä. Silva Fennica no. 77 article id 4627. https://doi.org/10.14214/sf.a9099
English title: Native and cultivated southern broadleaved tree species in Finland.
Original keywords: tammi; levinneisyys; jalava; kynäjalava; vuorijalava; jalot lehtipuut; lehmus; metsälehmus; metsävaahtera; saarni; puulajit; pohjoisraja
English keywords: deciduous trees; distribution; Quercus robur; small-leaved lime; elm; European white elm; broad-leaved trees; northern limit; Ulmus glabra; Ulmus laevis; wych elm; English oak; Norway maple; Acer platanoides; Tilia cordata; European ash; Fraxinus exelsior
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to update knowledge of natural range of English oak (Quercus robur L.), European ash (Fraxinus exelsior L.), Norway maple (Acer platanoides L.), small-leaved lime (Tilia cordata Miller), wych elm (Ulmus glabra Mill.) and European white elm (Ulmus laevis Pall.) in Finland, and estimate how far north they could be grown as forest trees or as park trees. The study is based on literature and questionnaires sent to cities and towns, District Forestry Boards, districts of Forest Service, Forestry Management Associations and railway stations.

The northern borders in the natural range of the species succeed one another from south to north as follows: English oak, European ash, Norway maple, wych elm, and small-leaved lime. Occurrence of European white elm is sporadic. The English oak forms forests in the southernmost Finland, while the other species grow only as small stands, groups or solitary trees. According to experiences of planted stands or trees, the northern limits of the species succeed one another from south to north as follows: European ash, English oak, Norway maple, European white elm, wych elm and small-leaved lime. All the species are grown in parks fairly generally up to the district of Kuopio-Vaasa (63 °). The northern limits where the species can be grown as park trees reach considerably further north in the western part of the country than in the east.

The article includes a summary in English.

  • Ollinmaa, E-mail: po@mm.unknown (email)
article id 4600, category Article
Aarne Nyyssönen. (1950). Vertailevia havaintoja hoidettujen ja luonnontilaisten männiköiden rakenteesta ja kehityksestä. Silva Fennica no. 68 article id 4600. https://doi.org/10.14214/sf.a9091
English title: Comparative study on structure and development of managed and natural Scots pine stands.
Original keywords: hakkuut; mänty; Pinus sylvestris; harvennushakkuu; kasvupaikkatyyppi; harvennus; luonnometsä; alaharvennus; läpimitan kasvu; tilavuuskasvu; latvuskerros
English keywords: natural forest; Scots pine; thinnings; diameter growth; fellings; increment; thinning from below; forest type; crown storey; tree classification
Abstract | View details | Full text in PDF | Author Info

The Forest Research Institute of Finland has established permanent sample plots to survey the effect of thinnings on the stands. This study compares the development of tended and natural Scots pine (Pinus sylvestris L.) stands growing on three different forest types: Oxalis-Myrtillus, Vaccinium and Calluna site type. The effect of heavy thinning from below (Oxalis-Myrtillus and Vaccinium site types) and increment felling (Calluna site type) was assessed by dividing the trees of the stands in tree classification classes according to their crown storey and defects.

The results show that thinning from below and increment thinning increase the proportion of trees in the 1st crown storey, which is already large in the natural stands. Also the diameter distribution is more even and the mean diameter higher after the thinnings.

In Scots pine stands in natural state, volume increment per stem is highest in the 1st crown storey and diminishes strongly towards the lower crown storeys. Thinnings increased the increment. The study indicates that many of the objectives of the intermediate cuttings, including promoting the growth of the best trees and improving the quality of the stand, have in general been achieved. Consequently, the thinnings give means to achieve the most valuable yield in the stand.

The article includes a summary in English.

  • Nyyssönen, E-mail: an@mm.unknown (email)
article id 4586, category Article
Risto Sarvas. (1948). Metsäpuiden rodunjalostuksesta. Silva Fennica no. 64 article id 4586. https://doi.org/10.14214/sf.a13988
English title: Forest tree breeding.
Original keywords: metsäopetus; metsänhoitajien jatkokurssit; metsähallinto; jatkokoulutus; Metsänjalostussäätiö; metsänjalostus
English keywords: forest administration; forest education; Foundation of Forest Tree Breeding; forest tree breeding
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 64 includes presentations held in the third professional development courses, arranged for foresters working in the public administration in 1947. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica.

This presentation introduces the aims and work of Foundation of Forest Tree Breeding, established in 1946.

  • Sarvas, E-mail: rs@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 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 4442, category Article
Lauri Ilvessalo. (1927). Cultivation of exotic tree species. Silva Fennica no. 4 article id 4442. https://doi.org/10.14214/sf.a8390
Keywords: silviculture; larch; exotic tree species
Abstract | View details | Full text in PDF | Author Info

Successful cultivation of a tree species outside its natural area of distribution involves that the original climate is similar to that of the area where it will be cultivated. Seeds should be procured from an area, where the climate is most similar to the area of cultivation. In addition, the site requirements should be met. To be worth of cultivation, the exotic tree species should offer advantages over the native species, such as wood quality, higher productivity, modest site requirement, greater endurance against spring frosts and cold in the winter, valuable by-products, resistance against grazing, insects or fungi, or improvement of soil.

In Finland, successful examples are Larix europaea Lam. &amp; A. DC. and Larix sibirica Lebed, which both give better yield than the native species, and have better resistance against decay. In Central Europe, Pseudotsuga mentziesii (Mirb.) Fnanko, Pinus strobus L. and Pinus sitchensis (Bong.) Carriére have proved to be good forest trees. In Hungary, Robinia pseudoacacia L. has become economically important. Eucalyptus spp. have been cultivated in the Mediterranean countries, South America and California.

A summary in Finnish is included in the PDF.

  • Ilvessalo, E-mail: li@mm.unknown (email)

Category : Article

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

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

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

The PDF includes a summary in English.

  • Keltikangas, E-mail: mk@mm.unknown (email)
  • Tiililä, E-mail: pt@mm.unknown
article id 7176, category Article
Olli Makkonen. (1967). Ancient forestry : an historical study. 1. Facts and information on trees. Acta Forestalia Fennica vol. 82 no. 3 article id 7176. https://doi.org/10.14214/aff.7176
Keywords: forestry; tree species; forests; history
Abstract | View details | Full text in PDF | Author Info

This paper presents a study on the works of ancient writers that deal with trees, forests and the use of forest before the time of actual forest sciences. The work describes the development of knowledge pertaining to the forest and trees and the progress made on utilizing them. This first part of a series of two articles is primarily concerned with biological information in ancient times. The article first describes the most important sources of information and concentrates then on the information on the structure of trees, on the vital functions of trees, on the factors affecting the growth of trees and tree species.

  • Makkonen, E-mail: om@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 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 7143, category Article
O. Meurman. (1963). Puutarhantutkimuslaitoksella Piikkiössä kokeilluista koristepuista ja -pensaista. Acta Forestalia Fennica vol. 76 no. 3 article id 7143. https://doi.org/10.14214/aff.7143
English title: Notes on ornamental trees and shrubs at the Department of horticulture (Piikkiö, Finland).
Original keywords: puulajit; alkuperä; pensaat; puutarhakasvit; talvenkestävyys; ulkomaiset lajit
English keywords: tree species; provenience; frost resistance; foreign species; garden plant; garden tree
Abstract | View details | Full text in PDF | Author Info

Trees and shrubs of foreign origin have been grown in Finland at least from the 1700th century. At the State Horticultural Institute in the neighbourhood of the town Turku in southwestern coast of the country, a number of ornamental trees and shrubs have been planted since 1927. During the first decade, weather conditions were quite favourable, but the winters in 1939–1940 were so severe, that only the hardiest plants survived.

It would be important to study hardiness and suitability of the various woody plants cultivated in the different parts of the country. This paper includes notes of the survival of the tree species and shrubs so far planted at the Institute.

The PDF includes a summary in English.

  • Meurman, E-mail: om@mm.unknown (email)
article id 7114, category Article
Paavo Yli-Vakkuri. (1960). Metsiköiden routa- ja lumisuhteista. Acta Forestalia Fennica vol. 71 no. 5 article id 7114. https://doi.org/10.14214/aff.7114
English title: Snow cover and ground frost in Finnish forests.
Original keywords: kuusi; mänty; lumipeite; lumi; routa; lehtipuut; kasvuolosuhteet
English keywords: Pinus sylvestris; Norway spruce; deciduous trees; Picea abies; Scots pine; snow; growth conditions; snow cover; ground frost
Abstract | View details | Full text in PDF | Author Info

Snow cover and ground frost was studied in 29 forest stands in Southern and Central Finland in 1957–1959. The tree species influenced greatly accumulation of snow on the forest floor. Norway spruce (Picea abies (L.) Karst.) retains snow in its crown. In addition, snow and water falling from the branches compress the snow cover under the trees, and the ground freezes deeper because of the shallow snow cover. In the spring, the dense crown prevents rain and radiation reaching the ground, which remains cold longer. However, ground frost may protect spruce, which has a weak root system, from wind damages.

Scots pine (Pinus sylvestris L.) has similar, but milder, effects on snow cover within the forest. The crowns of pine seedlings and young trees pass snow easily, but later the crowns intercept it considerably. The lower branches are, however, high up and the snow is evenly spread on the ground. The deciduous trees intercept little snow and in the spring the snow smelts and the frozen soil thaws early. The snow conditions of deciduous forests are, however, changed by a spruce undergrowth.

It can be assumed that the unfavourable conditions in spruce forests can be alleviated by thinning. Also, mixture of pine and deciduous trees can transform the conditions more favourable in the spruce stands.

The PDF includes a summary in English.

  • 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 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 7436, category Article
E. Salo. (1954). Puiden teknillinen vikaisuus ja sen vaikutus puuston arvoon. Acta Forestalia Fennica vol. 61 no. 24 article id 7436. https://doi.org/10.14214/aff.7436
English title: Technical defects of trees and their effect upon timber value.
Keywords: growing stock; settlement; land purchase; land value; defects of trees; Land Reclamation Act; reduction of value
Abstract | View details | Full text in PDF | Author Info

In acquiring land for the population displaced by the Second World War, the forest had to be priced, according to the Land Reclamation Act of 1945, separately for land and timber. Technical defects in the growing stock were to be taken account in the form of a total reduction in the value of the stock. Generally, it was to be 5-15% of the total value. The present investigation aims at checking the reduction percentages.

When the reduction in the felling value of the growing stock caused by the defects is estimated, the reduction is defined for each timber assortment, and the total reduction is calculated from these values. The timber assortments have big variation in prices, therefore defects in the most valuable assortments can have big effect on the total value of the growing stock. According to the study, the decree implementing the Land Reclamation Act did not in some cases allow for price reductions for defects on a sufficiently small scale to correspond to real conditions.

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

  • Salo, E-mail: es@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 7408, category Article
Kullervo Kuusela. (1953). On theory of forest increment calculation based on periodic measurements. Acta Forestalia Fennica vol. 60 no. 1 article id 7408. https://doi.org/10.14214/aff.7408
Keywords: forest stand; methodology; tree; normal forest; increment calculation
Abstract | View details | Full text in PDF | Author Info

The article presents the background of increment calculations and periodic measurements of forests, as well the historical development of increment calculations in North-America, Middle-Europe, Scandinavia and Finland. The measurements and calculations are presented for individual trees, for a forest stand and for the total resource of a normal forest stand.   

The practice of increment calculations has still some problems regarding the measurements of standing and harvested trees. The article discusses some ways to overcome the problems. 

  • Kuusela, E-mail: kk@mm.unknown (email)
article id 7397, category Article
Erkki K. Kalela. (1949). Ecological character of tree species and its relation to silviculture. Acta Forestalia Fennica vol. 57 no. 1 article id 7397. https://doi.org/10.14214/aff.7397
Keywords: forest management; succession; tree species; pioneer species; ecological succession; climax species; development of stands
Abstract | View details | Full text in PDF | Author Info

The tendency of successional development from young vegetation, rich in species and exposed to chance factors, towards regular plant communities, is found all around the world. Thee ecological groups of trees seem to be present in all forest regions in the world, namely the pioneer and the climax species, and a group of pre-climax species that can be ecologically either near the pioneer or the climax species. The succession of tree species in forest always leads to a climax stand, determined by climate, quality of soil and the mutual biotical strengths of the tree species in the region.

This division into ecological groups greatly facilitates choosing among different methods of treating stands and understanding the silvicultural methods of foreign regions. Stands formed by species of the same group must follow the same lines in their silvicultural treatment. For instance, mixed stand consisting of both pioneer and climax species represents a transition stage, in which the climax species strive for dominating position, and preservation of pioneer species is difficult. This indicates the broad lines for management of the stand. Also, regeneration methods of pioneer and climax species must be different. Studying the succession of natural forests can be used as a means to reach the highest possible silvicultural level. This is one reason why the preservation and study of virgin forests still in existence is indispensable.

The PDF includes a summary in Finnish.

  • Kalela, E-mail: ek@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 7358, category Article
Arvo Ylinen. (1942). The effect of the amount of the summer wood on the elastic and tensile properties of coniferous trees. Acta Forestalia Fennica vol. 50 no. 5 article id 7358. https://doi.org/10.14214/aff.7358
Keywords: coniferous trees; tensile properties; elasticity; summer wood; autumn wood; linear function
Abstract | View details | Full text in PDF | Author Info

The dependence of elastic and tensile properties of coniferous trees on the share of summer wood can be presented as linear functions, if the soft wood is considered as a statically indefinite structure. By eliminating the share of summer wood by a certain function presented in the article, the elastic and tensile properties are the linear functions of density.

The functions are proved right by conducting strength tests on pine. Practical implications of the derived functions in rating the quality of wood are also presented.

The PDF contains a summary in Finnish. 

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

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

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

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

The PDF contains a summary in Finnish. 

  • Paasio, E-mail: ip@mm.unknown (email)
article id 7338, category Article
Sakari Saarnijoki. (1937). Tampereen kaupungin ja sen lähiympäristön koristepuista ja -pensaista. Acta Forestalia Fennica vol. 46 no. 3 article id 7338. https://doi.org/10.14214/aff.7338
English title: Ornamental trees and shrubs in city of Tampere and the surrounding areas.
Original keywords: puisto; ulkomainen puulaji; marjapensas; hedelmäpuu; koristepensas
English keywords: park; garden; exotic species; shrub; fruit tree
Abstract | View details | Full text in PDF | Author Info

The article is a report of the exotic tree and shrub species found in major parks and gardens in the city of Tampere, in Southern Finland, and the surrounding areas, including fruit trees and berry bushes. The survey of species was conducted in 1934-1935. There was a total of 221 tree and shrub species in the 245 parks and gardens of the city. Exotic species was found 193, of which 37 was introduced only recently. The frequency of 199 species in Tampere area and the condition of each species is listed. Most common are the native species of the genus Picea, Pinus, Betula, Acer, Prunus and Sorbus. Of the exotic species only Malus pumila (Mill.) is commonly cultivated. Relatively common are Ulmus montana (With.), Tilia cordata (Mill.) and Fraxinus excelsior (L.).

The PDF includes a summary in German.

  • Saarnijoki, E-mail: ss@mm.unknown (email)
article id 7334, category Article
T. J. Hintikka. (1937). On fasciations and witches‘ brooms on (European) bird cherry trees (Prunus padus L.). Acta Forestalia Fennica vol. 45 no. 2 article id 7334. https://doi.org/10.14214/aff.7334
Keywords: Prunus padus; fasciation; witches’ broom; bird cherry tree; literatu review
Abstract | View details | Full text in PDF | Author Info

The article presents six fasciations found in Finland on bird cherry trees. Based on the literature it seems that fasciations are the precondition for witches’ brooms. The witches’ brooms on bird cherry trees are rare, but they have been mentioned in literature. Some views on their occurrence and development are represented. Also the possible causes behind the developments are discussed based on literature.  

The PDF contains a summary in Finnish.  

  • Hintikka, E-mail: th@mm.unknown (email)
article id 7303, category Article
J. Keränen. (1934). Lämpöoloista puiden ja eräiden pensaiden kasvupaikkojen pohjoisilla rajoilla Suomessa. Acta Forestalia Fennica vol. 40 no. 26 article id 7303. https://doi.org/10.14214/aff.7303
English title: Thermal conditions in the northern limits of some tree species and bushes in Finland.
Original keywords: levinneisyys; puulajit; pohjoisraja; lämpötila; ilmasto; pensaat
English keywords: tree species; climate; distribution; temperature
Abstract | View details | Full text in PDF | Author Info

The article discusses the thermal conditions in the northern limits of trees and some bushes in Finland. Temperature is the most important limiting factor for distribution of plant species. Precipitation variations, however, are small in Finland. The article lists the main features of thermal conditions during the different seasons in different parts of Finland. The northern limits and the thermal condition of the area are described for the following species: Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.), mezereon, buckthorn, common alder, linden, elm, maple, hazel, ash, oak, hybrid mountain ash, yew and Swedish whitebeam.

The PDF includes a summary in English.

  • Keränen, E-mail: jk@mm.unknown (email)
article id 7302, category Article
M. Lappi-Seppälä. (1934). Karsimisesta ja sen metsänhoidollisesta merkityksestä. Acta Forestalia Fennica vol. 40 no. 25 article id 7302. https://doi.org/10.14214/aff.7302
English title: The silvicultural influences of pruning.
Original keywords: puutavara; karsiminen; oksaton; vaneritukki; tukin laatu
English keywords: timber quality; tree growth; knottiness; value of timber
Abstract | View details | Full text in PDF | Author Info

Pruning growing trees influences tree growth and value of the wood and yield of timber of the stand. Pruning living branches create open wounds on the stems that can risk the growth of tree species that are vulnerable to injuries. For instance, pruning has been shown to cause decay in Norway spruce (Picea abies (L.) H. Karst.), while Scots pine (Pinus sylvestris L.) can quickly heal over the branch scars. Pruning of living branches reduces the crown, the effect of which remains small if only the lowest branches are pruned. Pruning of dry branches has little effect on the health of the tree. The main objective of pruning is to improve the quality of timber. Knottiness decreases strength and appearance of timber. Pruning increases the yield of knot-free sapwood, which is especially valuable in veneer timber. Pruning is, therefore, at present most suitable for birch and aspen which are used in veneer industry. In both species pruning should be directed mainly to dry branches.

The PDF includes a summary in German.

  • Lappi-Seppälä, E-mail: ml@mm.unknown (email)
article id 7297, category Article
A. L. Backman. (1934). Om den Åländska skogens förhistoria. Acta Forestalia Fennica vol. 40 no. 20 article id 7297. https://doi.org/10.14214/aff.7297
English title: Early history of forests in Åland, Finland.
Keywords: Pinus sylvestris; Betula; Picea abies; Finland; tree species; distribution; Alnus incana; occurrence; Åland; pollen analysis; paleobotany; Carpinus betulus
Abstract | View details | Full text in PDF | Author Info

The paper presents preliminary results of paleobotanical studies on vegetation in Åland, south-west Finland. The investigations concentrated on studying arrival of tree species and stratigraphy of peatlands. According to the studies, some plant fossils found in the peat (Ceratophyllum submersum, Sparagnium neglectum, Najas flexilis) indicate that climate of the region has earlier been warmer than at the present. The present forests in Åland are dominated by coniferous species, but the pollen analysis of the peat indicate that Norway spruce (Picea abies (L.) H. Karst.) became a common species in the region about by the time of Christ’s birth. The species has reached its present distribution in Åland relatively late. The pollen analyses give relatively little information about the arrival of birch (Betula sp.) and Scots pine (Pinus sylvestris L.), but it seems obvious that occurrence of birch reached its culmination just before spruce. During the warm period common alder (Alnus glutinosa (L.) Gaertn.) was the most important species, and also pollen of oak (Quercus robur L.), kinden (Tilia cordata L.) and elm (Ulmus sp.) was relatively common in the peat of some of the studied peatlands. An interesting finding was the pollen of Carpinus betulus in many sites in Åland.

The PDF includes a Finnish and German summary.

  • Backman, E-mail: ab@mm.unknown (email)
article id 7295, category Article
O. J. Lukkala. (1934). Lounais-Suomen metsien puulajihistoriasta. Acta Forestalia Fennica vol. 40 no. 18 article id 7295. https://doi.org/10.14214/aff.7295
English title: The history of tree species in southwest Finland.
Original keywords: suo; puulajisuhteet; siitepölyanalyysi
English keywords: peatland; tree species composition; pollen analysis
Abstract | View details | Full text in PDF | Author Info

Pollen analysis has given information on development of the tree species composition after the ice age, but this kind of studies have not been published in Finland. In this study, pollen analysis was performed in five peatlands in the southwest Finland. According to the analysis, the forests of the area have had similar tree species composition for many thousands of years. Scots pine (Pinus sylvestris L.) has been the dominant species as long as there has been Norway spruce (Picea abies (L.) H. Karst.) in the area. Norway spruce seems to have arrived about 4,500 years ago. It increased slowly in the beginning, and after reaching a maximum has been slowly decreasing. Before spruce arrived, Betula sp. was more abundant, and seemed to be the dominant tree species in some places. Traces of fire in the peat layers indicate that forest fires have been common before people arrived in the area, and may have beneficial to birch. Like Betula sp., also Alnus sp. were more common before spruce arrived. Also pollen of other broadleaved species, for example, Tilia sp., Ulmus sp. and Corylus could be found. However, Quercus pollen was not found. The paludification of the peatlands had begun at different times which indicates that there has not been a common cause for the development of the peatlands in the area.

The PDF includes a summary in German.

  • Lukkala, E-mail: ol@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 7225, category Article
A. E. Osmaston. (1929). On the forest types in India. Acta Forestalia Fennica vol. 34 no. 12 article id 7225. https://doi.org/10.14214/aff.7225
Keywords: tree species; indicator species; forest site type; indicator plants; India
Abstract | View details | Full text in PDF | Author Info

Forest site type classification based on the vegetation has not been developed in India. The classifications made by forest officers have been based on the upper storeys of trees. Shrubs have been used to class such sites where grasses are the dominant species. However, some observers in India have used grass and bamboo species to identify sites suitable on unsuitable for certain valuable tree species. In Burma, some bamboo species have been noticed to be good indicators for sites suitable or unsuitable for teak (Tectona grandis L. f.). Studies in the western sub-Himalayan area suggest that certain grasses could be used as indicators for sites suitable for sal (Shorea robusta Gaertn.). Grasses have also been identified as indicators for certain kinds of forests and soils in the area between Ganges and the Jumna.

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

  • Osmaston, E-mail: ao@mm.unknown (email)
article id 7218, category Article
John W. Harshberger. (1929). The forests of the Pacific coasts of British Columbia and Southeastern Alaska. Acta Forestalia Fennica vol. 34 no. 5 article id 7218. https://doi.org/10.14214/aff.7218
Keywords: forest site types; dominant species; coniferous tree species
Abstract | View details | Full text in PDF | Author Info

The vegetation in the Pacific coasts of British Columbia and Southeastern Alaska resemble the vegetation in the northern Fennoscandia. The national forests have been divided in two parts: Tongass and Chugach national forests. Both of the forests are fairly uniform in their vegetation. The forests have few coniferous tree species as the dominant species from south to north, Sitka spruce (Picea sitchensis (Bong.) Carrière) and western hemloch (Tsuga heterophylla (Raf.) Sarg.). It is difficult to distinguish forest site types, but it is probable that the forest lands in Alaska and British Columbia could be delimited to similar forest site types as professor Cajander established in Finland.

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

  • Harshberger, E-mail: jh@mm.unknown (email)
article id 7217, category Article
Bunzo Hayata. (1929). Succession in the vegetation of Mt. Fuji. Acta Forestalia Fennica vol. 34 no. 4 article id 7217. https://doi.org/10.14214/aff.7217
Keywords: tree species; altitude; natural selection; Japan; succession of forests
Abstract | View details | Full text in PDF | Author Info

­In different altitudes of the Mount Fuji in Japan occur succession of different tree species. For instance, at an altitude of 2,000 meters are pure stands of Tsuga diversifolia (Maxim.), under which is generally found young trees of Abies veitchii (Lindl.), but not of Tsuga. Abies veitchii is in its turn replaced perhaps with Larix sp. The succession of the forests of the volcano have reached maturity, which is not the case in the east–north-east flank of the mountain, where the Hōei eruption destroyed all vegetation in 1707. The vegetation had not revived even by the 1920s. The Hōei eruption site is compared to the much faster return of vegetation in mount Krakatau in the warmer tropical region. The succession of forests in the other parts of the mountain is described in detail. Finally, a succession theory is proposed that is opposed to the natural selection theory. The theory suggests that there is an Innermost Factor that controls the plant succession. According to the theory, every species, every formation, should die its natural death owing to the Innermost Factor.

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

  • Hayata, E-mail: bh@mm.unknown (email)
article id 7216, category Article
L. Cockayne. (1929). Hybridism in the forests of New Zealand. Acta Forestalia Fennica vol. 34 no. 3 article id 7216. https://doi.org/10.14214/aff.7216
Keywords: tree species; hybrid; polymorphism; hybridization
Abstract | View details | Full text in PDF | Author Info

The article gives examples of hybridization of forest tree and shrub species in the forests of New Zealand. According to the article, many of the 498 vascular plant species in the forest communities of the New Zealand region must be excluded from the standpoint of hybridism, because they belong either to genera of one species or are unable to cross owing to geographical or biological isolation. The hybrids are in most cases jordanons which cross, and may be more or less distantly related or closely related. The hybrids occur usually in polymorphic groups. Most of the hybrids in New Zealand are fertile. The hybrids can affect the forest communities in two ways; by effecting their composition or their structure. The article includes a list of hybrid groups.

Jubileum publication of professor Aimo Kaarlo Cajander.

  • Cockayne, E-mail: lc@mm.unknown (email)
article id 7197, category Article
Erik Lönnroth. (1926). The stereometric mean tree of the stand. Acta Forestalia Fennica vol. 30 no. 2 article id 7197. https://doi.org/10.14214/aff.7197
Keywords: mean tree; average tree; stereometry; stereometric; statistical numbers
Abstract | View details | Full text in PDF | Author Info

The mean has a great importance in statistics in general and also in forest statistical calculations. The meaning of the average tree and its characteristics is important also for the practical forest mensuration work. However, the question is how are the statistical numbers of a mean tree related to the statistical numbers of the stand.   

Study is based on the strip-wise survey of forests in southern Finland. From that information the 30 sample plots were chosen, 10 of each of most typical forest site types, MT, VT and CT. The stands are of different ages and development classes, varying from 14 to 159 years.

For the determination of the average tree are the statistical numbers of five characteristics needed: volume, basal area, diameter, height and form factor. The stereometric mean tree of the stand can be calculated with only one statistical method and that solution is absolute.

Theoretically and statistically absolute solution for the problem is the continuous solution by the mean that is weighted with the number of stems. This solution however is not very useful in practical sense.

A simple, practical and adequately exact solution for determining the average tree by approximation procedure of a certain arithmetic mean. 

  • Lönnroth, E-mail: el@mm.unknown (email)
article id 7191, category Article
V. T. Aaltonen. (1925). On the influence of trees to each other. Acta Forestalia Fennica vol. 29 no. 1 article id 7191. https://doi.org/10.14214/aff.7191
Keywords: growth factor; tree; interactions
Abstract | View details | Full text in PDF | Author Info

The article discusses the growth factors, the influence of the seed tree to the seedlings and the relations of the trees within one age class in sense of growth of the trees and their effect for practical forest management.

The author concludes by noticing that there is a remarkable gap in knowledge about growth factors and more research is needed especially on the interactions of various growth factors. Earlier research on forests has not taken the characteristics of the site and its effect into account adequately. In addition to the observations in the nature, the individual growth factors and their interactions should be studied quantitatively.    

  • Aaltonen, E-mail: va@mm.unknown (email)
article id 7075, category Article
A. F. Tigerstedt. (1922). Mustilan kotikunnas. Acta Forestalia Fennica vol. 24 no. 2 article id 7075. https://doi.org/10.14214/aff.7075
English title: The Mustila arboretum.
Original keywords: ulkomaiset puulajit; dendrologia; puulaji
English keywords: tree species; exotic tree species; dendrology
Abstract | View details | Full text in PDF | Author Info

The article describes experiences in exotic tree and shrub species in Mustila arboretum in 1901-1921, situated in Southern Finland. Mustila is the first arboretum of the country, established in 1901. The tree species have mostly been planted as small stands or groups of trees. The objective has been to find species that suit the Finnish climate. The article describes experiences of cultivation trials of coniferous tree species from the genus of Taxus, Tsuga, Pseudotsuga, Abies, Picea, Larix, Pinus, Thyopsis, Thuya, Chamaecyparis and Juniperus, in total 100 different species. The climate of Finland ranges from maritime to semi-maritime and semi-continental, becoming more continental towards the eastern parts of the country. According to the experiments, in Mustila area most promising are the Western American species from regions that are suitable distance from the Pacific Ocean. The exact origin of the seeds in the America is important for the survival of the species in Finland.

The PDF includes a summary in English.

  • Tigerstedt, E-mail: at@mm.unknown (email)
article id 7074, category Article
Aimo Kaarlo Cajander. (1923). Cultivation of exotic tree species as forestry and plant geographic problem. Acta Forestalia Fennica vol. 24 no. 1 article id 7074. https://doi.org/10.14214/aff.7074
Keywords: tree species; cultivation; provenience; exotic
Abstract | View details | Full text in PDF | Author Info

The distribution and occurrence of plant species, including trees, in the nature show that living and splendor of them is constrained by climatic factors. They have their minimum, optimum and maximum for the temperatures they can survive in. The tree species, at least mostly are divided into different varieties in different areas of the world so that the species are most suitable for the climatic conditions of their site.

The article presents the main climatic zones with their tree species according L. Ilvessalo and they suitability to Finland. More accurate areas of suitable species are also listed. 

The referred results show that alongside the climatic conditions, the conditions of soil and relief must be taken into account when using exotic tree species for forestry purposes.  

  • Cajander, E-mail: ac@mm.unknown (email)
article id 7067, category Article
Aimo Kaarlo Cajander. (1921). Reflections on the evolution of the species, especially on arborescent plants. Acta Forestalia Fennica vol. 21 no. 3 article id 7067. https://doi.org/10.14214/aff.7067
Keywords: pine; tree species; ; evolution; arborescent; Pinus sp.
Abstract | View details | Full text in PDF | Author Info

The most abundant tree species occur in different variants in different geographical regions. They differ in their genetic, biological and partly also in morphological characters, however making clear difference between these subspecies is not possible. The different subspecies have developed according the respective areas' climatic and soil conditions, developing adaptive characters. These subspecies play a great role in practical forest management, since they differ in for forestry important characters, such as cold tolerance or stem form. 

The subspecies hybridize with each other in areas where their distribution areas overlap. In these areas the subspecies cannot be always clearly defined.   

  • Cajander, E-mail: ac@mm.unknown (email)
article id 7050, category Article
Lauri Ilvessalo. (1920). Ulkomaalaisten puulajien viljelymahdollisuudet Suomen oloja silmälläpitäen. Acta Forestalia Fennica vol. 17 no. 2 article id 7050. https://doi.org/10.14214/aff.7050
English title: Prospects of cultivating exotic tree species in Finland.
Original keywords: alkuperä; ulkomaiset puulajit; ilmasto
English keywords: provenance; climate; exotic tree species
Abstract | View details | Full text in PDF | Author Info

The article includes a dendrological review on the effect of climate to the success of cultivation of exotic tree species, based on literature and analysis of the existing Finnish field tests. The cultivation of an exotic tree species succeeds only if the seed has been procured from an area, which climate is similar to the place of cultivation. Climate is even more important than site quality.

Finnish climate is boreal and continental, and thus tree species of similar climate suit here best. In favorable site conditions it is possible to grow also species from boreal marine, and temperate climates. Finnish summers are not warm enough for species from temperate continental climate to get prepared for the winter, and the shoots can get frost damages. This may be compensated with a warm and sheltered site. If the species tolerates shading, it can be planted under sheltering trees. For species from maritime boreal climate, the Finnish summer tends to be too short, and the winters too cold. A suitable site is rich, warm and sheltered, and has preferably a protective sparse tree cover. Species from southern maritime climate cannot be grown in Finland. The provenance of the seeds is also very important. An important source of seeds are the successful plantations in Finland.

The PDF includes a summary in German.

  • Ilvessalo, E-mail: li@mm.unknown (email)
article id 7041, category Article
Yrjö Ilvessalo. (1920). Tutkimuksia metsätyyppien taksatoorisesta merkityksestä nojautuen etupäässä kotimaiseen kasvutaulujen laatimistyöhön. Acta Forestalia Fennica vol. 15 no. 3 article id 7041. https://doi.org/10.14214/aff.7041
English title: Studies on mensurational significance of forest site types as part of preparation of Finnish growth and yield tables.
Original keywords: metsätyypit; kasvupaikkatyypit; kasvu- ja tuotostaulukot
English keywords: tree growth; growth and yield tables; forest site types
Abstract | View details | Full text in PDF | Author Info

New growth and yield tables were prepared for Southern Finland. To finalize the tables, it had to be determined whether the forest site types developed by Cajanus could be used in mensurational research.

Comparative study was performed in 1916-1919 to study the growth of the trees in different forest site types. Total of 467 sample sites were measured in Southern and Central Finland. All the forest site types were found to have a distinctive vegetation typical to the site. It can be concluded that the ground vegetation can be used to determine the forest site type. The growth of trees was different in different forest site types, yet similar within each site type. The forest site types are uniform, natural and easy to determine, and can thus be used to classify the forest stands and used in mensurational research and a basis to growth and yield tables.

The PDF includes a summary in German.

  • Ilvessalo, E-mail: yi@mm.unknown (email)
article id 7034, category Article
V. T. Aaltonen. (1920). The distribution and abundance of the tree roots in the heathy forests on Lapland. Acta Forestalia Fennica vol. 14 no. 1 article id 7034. https://doi.org/10.14214/aff.7034
Keywords: pine; root system; heath; heathy forests; tree root; root competition; rootage
Abstract | View details | Full text in PDF | Author Info

The study presents and describes the abundance and distribution of tree roots in specific stands of heathy forest types in Lapland. The data was collected in the Sodankylä commune.  

Due to the shortcomings in the data, conclusions can be drawn only regarding pine forests. The result of study states that the root competition plays an important role in the development of the forests, and most of the other observed phenomena are linked with root competition. The more infertile the soil the vertically and horizontally wider and more abundant the root system. It seems that the abundance of the root system is similar in forest of same fertility class and same density and age.      

  • Aaltonen, E-mail: va@mm.unknown (email)
article id 7020, category Article
S. E. Multamäki. (1919). Tutkimuksia metsien tilasta Savossa ja Karjalassa. Acta Forestalia Fennica vol. 9 no. 2 article id 7020. https://doi.org/10.14214/aff.7020
English title: Studies on state of forests in Savo and Karelia.
Original keywords: metsänhoito; linja-arviointi; metsävarat; metsätyyppi; metsänarviointi; puulajisuhteet
English keywords: forest management; forest resources; forest mensuration; forest site type; strip survey; distribution of tree species
Abstract | View details | Full text in PDF | Author Info

A strip survey was made to define the forest and peatland site class distribution and the condition of the forests in Savo and Karelia in central and eastern parts of Finland. According to the survey, 24% of the forested lands are peatlands. Fresh mineral soil sites (26%) were the most common mineral soil site type. Intermediately dry forest soil sites covered 22% of the area, forest sites with grass-herb vegetation 12,79%, rich grass-herb forest soil sites 3,16% and dry forest soil sites 9,59% of the forested area. The most common tree species were Scots pine (Pinus sylvestris L.), 39%, Betula sp., 26%, Norway spruce (Picea abies (L.) H. Karst.), 18%, and grey alder (Alnus incana (L.) Moench), 10% of the forest land. The article includes a review about the wood harvesting in the forests, and their present silvicultural state. According to the study, about 30% of the forested lands (not including peatlands) were unproductive; mostly mixed alder and birch stands of poor quality or open lands.

The PDF includes a summary in German.

  • Multamäki, E-mail: sm@mm.unknown (email)
article id 7011, category Article
Antti Tanttu. (1915). Tutkimuksia ojitettujen soiden metsittymisestä. Acta Forestalia Fennica vol. 5 no. 2 article id 7011. https://doi.org/10.14214/aff.7011
English title: Studies on forest growth of drained peatlands.
Original keywords: ojitus; räme; neva; korpi; turvekangas
English keywords: draining; pine swamp; treeless bog; spruce swamp
Abstract | View details | Full text in PDF | Author Info

Draining of peatlands to improve forest growth started to increase in Finland in the beginning of 1900s. The aim of the study was to find out which kind of peatlands are suitable for draining. The peatlands examined in this study had been drained earlier in 1800s for other purposes, and the original peatland type was deduced afterwards. When the peatland is drained, its vegetation changes gradually towards that of mineral soil sites, depending on the original peatland type. The article includes detailed description of the vegetation on different drained peatland sites. Best represented in the study were different types of pine swamps, which change towards Calluna or Vaccinium forest site type depending on the original peatland type. The Sphangnum species and brushwood disappear gradually and Cladina sp. become common in some drained pine swamp types. Scots pine (Pinus sylvestris L.) regenerates well on most drained pine swamps, and also Betula sp may grow as dominant species. The richer pine swamp types develop to Vaccinium-myrtillus forest site type, which may grow also Norway spruce (Picea abies (L.) H. Karst). Drained treeless bogs change first towards pine swamps. However, trees regenerate poorly on these sites and the growth is low. Flark-bogs develop typically to treeless lichen heaths. Drained spruce swamps develop to forest with grass-herb vegetation or Myrtillus site type.

The PDF includes a summary in German.

  • Tanttu, E-mail: at@mm.unknown (email)
article id 7534, category Article
Olli Heikinheimo. (1915). Kaskiviljelyksen vaikutus Suomen metsiin. Acta Forestalia Fennica vol. 4 no. 2 article id 7534. https://doi.org/10.14214/aff.7534
English title: The effect of shifting cultivation on forests in Finland.
Original keywords: metsätalous; kaskiviljely; maanviljely; puulajisuhteet
English keywords: forestry; shifting cultivation; agriculture; distribution of tree species
Abstract | View details | Full text in PDF | Author Info

The article is a review on shifting cultivation, its methods and use in Finland, and its effect on the condition of forests. Shifting cultivation decreases forest reserves not only by burning large amounts of wood. Of the area used for shifting cultivation, 10-50% can be open land. The older age classes of forests are often missing, and range of tree species shift towards deciduous trees. This causes lack of large timber. The shorter the rotation, the less well the most valuable trees survive on the area. One reason is lack of seed trees. Of the coniferous trees, Scots pine (Pinus sylvestris L.) is able to survive in the burnt-over lands better than Norway spruce (Picea abies (L.) H. Karst.), because it can produce seeds at a relatively young age. Betula sp. and especially grey alder (Alnus incana (L.) Moench) regenerate well on burnt-over lands. Also the frequency of good seed years determine which tree species become the dominant species on a burnt-over site.

When shifting cultivation is abandoned, deciduous trees keep their advantage over coniferous trees, because the wood of coniferous trees is used more in the surrounding villages. Pine and spruce spread to the burnt-over areas from the poorer sites that often had remained unburned. In densely populated areas in some counties in Savo in eastern Finland, where shifting cultivation was practiced intensively, Norway spruce became rare. Dominant tree species in the burnt-over areas became birch and pine.

The article is divided in two parts. A German summary is included in a separate PDF
  • Heikinheimo, E-mail: oh@mm.unknown (email)
article id 7528, category Article
Einari Vuori. (1913). Coniferous tree stands of the state forest “Vesijako” reforested through controlled burning. Acta Forestalia Fennica vol. 2 no. 1 article id 7528. https://doi.org/10.14214/aff.7528
Keywords: Alnus incana; grey alder; prescribed burning; forest improvement; coniferous trees; controlled burning; white alder
Abstract | View details | Full text in PDF | Author Info

The study area is state owned forest of Vesijako in southern middle Finland that has earlier been intensively managed with slash-and-burn agriculture. Reforestation of broad-leaved forests into coniferous forest with controlled burning has been studied on 76 sample plots.

The article describes the practice of leasing forest stands to leaseholders who executed the controlled burning and forest regeneration and management according a leasing contract. The results of the reforestation with coniferous trees shows that sowed pine (Pinus silvestris) stands give good results but spruce (Picea abies) must be planted as a seedling.  For the state this method of forest improvement is cost effective  and should be used more widely. 

  • Vuori, E-mail: ev@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 7517, category Article
Juha Nurmi. (1997). Heating values of mature trees. Acta Forestalia Fennica no. 256 article id 7517. https://doi.org/10.14214/aff.7517
Keywords: biomass; conifers; tree species; lignin; broadleaved trees; heating value; logging residue; carbohydrates
Abstract | View details | Full text in PDF | Author Info

The effective heating values of the above and below ground biomass components of mature Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), downy birch (Betula pubescens Ehrh), silver birch (B. pendula Roth), grey alder (Alnus incana (L.) Moench), black alder (A. glutinosa (L.) Gaertn.) and aspen (Populus tremula L.) were studied. Each sample tree was divided into wood, bark and foliage components. Bomb calorimetry was used to determine the calorimetric heating values.

The species is a significant factor in the heating value of individual tree components. The heating value of the wood proper is highest in conifers. Broadleaved species have a higher heating value of bark than conifers. The species factor diminishes when the weighted heating value of crown, whole stems or stump-root-system are considered. The crown material has a higher heating value per unit weight in comparison with fuelwood from small-sized stems or whole trees. The additional advantages of coniferous crown material are that it is non-industrial biomass resource and is readily available. The variability of both the chemical composition and the heating value is small in any given tree component of any species. However, lignin, carbohydrate and extractive content were found to vary from one part of the tree to another and to correlate with the heating value

  • Nurmi, E-mail: jn@mm.unknown (email)
article id 7503, category Article
Anssi Niskanen, Olavi Luukkanen, Olli Saastamoinen, Suree Bhumibhamon. (1993). Evaluation of the profitability of fast-growing tropical trees. Acta Forestalia Fennica no. 241 article id 7503. https://doi.org/10.14214/aff.7503
Keywords: cost-benefit analysis; profitability; Thailand; development forestry; tree plantations; environmental impacts
Abstract | View details | Full text in PDF | Author Info

The profitability of fast-growing trees (Eucalyptus camaldulensis Dehnh., Acacia mangium Willd. and Melia azedarach L.) was investigated in the north-eastern and eastern provinces of Thailand. The financial, economic, and tentative environmental-economic profitability was determined separately for three fast-growing plantation tree species and for three categories of plantation managers: the private industry, the state (the Royal Forest Department) and the farmers. Fast-growing tree crops were also compared with teak (Tectona grandis L. f.), a traditional medium or long rotation species, and Para rubber (Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg.) which presently is the most common cultivated tree in Thailand.

The optimal rotation for Eucalyptus camaldulensis pulpwood production was eight years. This was the most profitable species in pulpwood production. In sawlog production Acacia mangium and Melia azedarach showed a better financial profitability. Para rubber was more profitable and teak less profitable than the three fast-growing species. The economic profitability was higher than the financial one, and the tentative environmental-economic profitability was slightly higher than the economic profitability.

The profitability of tree growing is sensitive to plantation yields and labour cost changes and especially to wood prices. Management options which aim at pulpwood production are more sensitive to input or output changes than those options which include sawlog production. There is an urgent need to improve the growth and yield data and to study the environmental impacts of tree plantations for all species and plantation types.

The PDF includes a summary in Finnish.

  • Niskanen, E-mail: an@mm.unknown (email)
  • Luukkanen, E-mail: ol@mm.unknown
  • Saastamoinen, E-mail: os@mm.unknown
  • Bhumibhamon, E-mail: sb@mm.unknown
article id 7685, category Article
Risto Ojansuu. (1993). Prediction of Scots pine increment using a multivariate variance component model. Acta Forestalia Fennica no. 239 article id 7685. https://doi.org/10.14214/aff.7685
Keywords: Pinus sylvestris; crown height; volume increment; bark volume; variance component models; multivariate models; stem curve models; tree form change
Abstract | View details | Full text in PDF | Author Info

Diameter and volume increment as well as change in stem form of Scots pine (Pinus sylvestris L.) were analysed to predict tree increment variables. A stem curve set model is presented, based on prediction of the diameters at fixed angles in a polar coordinate system. This model consists of three elementary stem curves: 1) with bark, 2) without bark, and 3) without bark five years earlier. The differences between the elementary stem curves are the bark curve and the increment curve. The error variances at fixed angles and covariances between the fixed angles are divided into between-stand and within-stand components. Using principal components, the between-stand and within-stand covariance matrices are condensed separately for stem curve with bark, bark curve and increment curve. The two first principal components of the bark curve describe the vertical change in Scots pine bark type and the first principal component of the increment curve describes the increment rate. The elementary stem curves, bark curve and increment curve as well as corresponding stem volumes, bark volume and volume increment can be predicted for all trees in the stand with free choice of sample tree measurements. When only a few sample trees are measured, the stem curve set model gives significantly more accurate predictions of bark volume and volume increment for tally trees than does the volume method, which is based on the differences between two independent predictions of volume. The volume increment of tally trees can be predicted as reliably with as without measurement of sample tree height increment.

The PDF includes a summary in English.

  • Ojansuu, E-mail: ro@mm.unknown (email)
article id 7682, category Article
Juha Nurmi. (1993). Heating values of the above ground biomass of small-sized trees. Acta Forestalia Fennica no. 236 article id 7682. https://doi.org/10.14214/aff.7682
Keywords: heating value; small-sized trees; whole-tree biomass; wood chemistry
Abstract | View details | Full text in PDF | Author Info

The heating values of wood, inner and outer bark, and foliage components of seven small-size tree species (Pinus sylvestris L., Picea abies (L.) H. Karst., Betula pubescens Erhr., B. pendula Roth, Alnus incana (L.) Moench, A. glutinosa (L.) Gaertn., Populus tremula L.) were studied. Significant differences were found between species within each component. However, the differences between species for weighted stem, crown and whole-tree biomass are very small. The weighted heating value of the crown mass is slightly higher than that of the stem in all species. The heating value of stem, crown and whole-tree material was found to increase with increasing latitude.

The effective heating value of wood correlated best with the lignin content, inner bark with carbohydrate, and outer bark with carbohydrates and the extractives soluble in alkalic solvents. It is suggested that the determination of the heating value might be used as an indicator of the cellulose content of coniferous wood.

The PDF includes a summary in Finnish.

  • Nurmi, E-mail: jn@mm.unknown (email)
article id 7678, category Article
Lauri. Valsta. (1992). An optimization model for Norway spruce management based on individual-tree growth models. Acta Forestalia Fennica no. 232 article id 7678. https://doi.org/10.14214/aff.7678
Keywords: Norway spruce; Picea abies; thinning; optimization; stand management; rotation; initial density; individual-tree simulator
Abstract | View details | Full text in PDF | Author Info

A nonlinear programming algorithm was combined with two individual-tree growth simulators consisting of distance-independent diameter and height growth models and mortality models. Management questions that can be addressed by the optimization model include the timing, intensity and type of thinning, rotation age, and initial density. The results were calculated for Norway spruce (Picea abies (L.) H. Karst.) stands on Oxalis-Myrtillus site in Southern Finland, where the stand density after clearing of a seedling stand is about 2,000 trees/ha.

The optimum thinning programs were characterized by late first thinnings (at dominant height of 15–17 m) and relatively high growing stock levels. It was optimal to thin from above, unless mean annual increment was maximized instead of an economic objective. In most cases, the optimum number of thinnings was two or three. Compared to a no-thinning alternative, thinnings increased revenues by 15 –45% depending on the objective of stand management. Optimum rotation was strongly dependent on the interest rate.

Hooke and Jeeves’ direct search method was used for determining optimum solutions. The performance of the optimization algorithm was examined in terms of the number of functional evaluations and the equivalence of the objective function values of repeated optimizations.

The PDF includes a summary in Finnish.

  • Valsta, E-mail: lv@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 7629, category Article
Pekka Kilkki. (1983). Sample trees in timber volume estimation. Acta Forestalia Fennica no. 182 article id 7629. https://doi.org/10.14214/aff.7629
Keywords: methods; sample trees; volume of the stand
Abstract | View details | Full text in PDF | Author Info

Analysis of sample tree data showed that the major part of the residual variation of the stem volume estimates occurs within the forest stands. The division of the residual variation into the variation within and between populations is the basis for the mean-square error formulae of the volume estimators. Efficiency of different sample tree measurement combinations has been studied by comparing the errors of the volume estimates to the sampling costs. The measurement of the upper diameter (d6) is of less value than is generally suggested.

The PDF includes a summary in Finnish.

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

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

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

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

The PDF includes a summary in Finnish.

  • Chung, E-mail: mc@mm.unknown (email)
article id 7590, category Article
Jukka Sarvas. (1977). Mathematical model for the physiological clock and growth. Acta Forestalia Fennica no. 156 article id 7590. https://doi.org/10.14214/aff.7590
Keywords: forest trees; annual cycle; physiological clock
Abstract | View details | Full text in PDF | Author Info

In this paper a precise definition is given of the term physiological clock and the role of this clock in biological developmental and growth processes is mathematically studied. The heat sum method employed in the study of the annual cycle of development of forest trees has been used as the starting point. The mathematical principles of this method are analysed and it is shown that, on the same principles, a fairly general physiological clock can be constructed. Also, two growth models are presented in which this generalized physiological clock proves to play an important role.

The PDF includes a summary in Finnish.

  • Sarvas, E-mail: js@mm.unknown (email)
article id 7580, category Article
Seppo Kellomäki. (1975). Forest stand preferences of recreationists. Acta Forestalia Fennica no. 146 article id 7580. https://doi.org/10.14214/aff.7580
Keywords: tree species; mixed forests; recreation; forest landscape; nature; outdoorsman; scenery; scenic beauty; scenic value
Abstract | View details | Full text in PDF | Author Info

The environmental preferences of recreationists were studied at the forest stand level in this study. The hypothesis which has been drawn up on the basis of the literature has been studied by attempting to elucidate the environmental preferences of groups using two recreation areas owned by the City of Helsinki using interviews and questionnaires. The material consisted of 1,323 interviews supplemented by questionnaires.

The replies to the questionnaires showed that recreationists consider birch and Scots pine to be more beautiful than Norway spruce, and stands made up of several tree species to be more beautiful than stands of single tree species. They also consider mature stands to be more beautiful than young stands.

During the interviews, the attention of the recreationists was directed at the view formed by the interview stand. The scenic preferences for the stands were measured using adjectives which the interviewee was asked to use in describing his or her impression of the view which was pointed out. First of all, the results clearly indicated that from the point of view of the scenic value of the stand, the way in which the stand is organised to form a scenic aspect or a stand view is more important than its ecological structure. However, it is obvious that stands containing large sized trees in particular are in many ways more preferred than stands which are younger in their development stage. This should therefore be the case when changes in the stand view resulting from management measures are insignificant or difficult to see. The main tree species in the stand does not seem to have from the point of view of scenic preference as much significance as would have been expected judging by the questionnaire material.

The PDF includes a summary in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
article id 7579, category Article
Pekka Kilkki, Markku Siitonen. (1975). Metsikön puuston simulointimenetelmä ja simuloituun aineistoon perustuvien puustotunnusmallien laskenta. Acta Forestalia Fennica no.