Current issue: 53(3)

Under compilation: 53(4)

Impact factor 1.683
5-year impact factor 1.950
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles containing the keyword 'stems'.

Category: Research article

article id 1657, category Research article
Razvan Vasile Campu, Arcadie Ciubotaru. (2017). Time consumption and productivity in manual tree felling with a chainsaw – a case study of resinous stands from mountainous areas. Silva Fennica vol. 51 no. 2 article id 1657. https://doi.org/10.14214/sf.1657
Highlights: An important preoccupation in sustainable logging management is represented by the analysis of work time structure and productivity level in manual tree felling with a chainsaw; Sound knowledge of the factors which influence work time allows better planning of harvesting operations so that deadlines could be met and damage to forest ecosystems be minimized.

The purpose of this research is to establish time consumption and productivity when using Husqvarna 365 chainsaw for resinous tree felling in mountainous regions. The research was conducted in the Romanian Southern Carpathians, in two mixed spruce (Picea abies (L.) H. Karst.) and fir (Abies alba Mill.) tree stands (S1 and S2). Only one team of workers, made up of a feller and an assistant, was used in the felling operation. This was divided into nine specific stages for which work times were measured. Work time structure used here includes WP – workplace time (PW – productive work time; SW – supportive work time, NT – non-work time) and NW – non-workplace time. The results indicated a productivity of 10.138 m3 h–1 (4.55 tree h–1) in S1 and of 11.374 m3 h–1 (4.33 tree h–1) in S2. Work time structure was WP 88.61% (PW 19.59%; SW 33.88%; NT 35.14%) and NW 11.39% in S1 and WP 83.77% (PW 17.66%; SW 30.73%; NT 35.38%) and NW 16.23% in S2. The results obtained showed that the power function best describes the relationship between productivity expressed by tree h–1 and breast height diameter (dbh) (R2 = 0.89 in S1 and R2 = 0.94 in S2). When productivity is expressed by m3 h–1 the results obtained in the case of power, exponential and linear functions are comparable (R2 = 0.65 to 0.67 in S1 and R2 = 0.81 to 0.92 in S2). Productivity is also influenced by stump diameter and the distance between trees. Their influence on productivity was emphasized by linear regression equations.

  • Campu, Transilvania University of Braşov, Faculty of Silviculture and Forest Engineering, Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Şirul Beethoven no. 1, 500123, Braşov, Romania ORCID ID:E-mail: vasile.campu@unitbv.ro (email)
  • Ciubotaru, Transilvania University of Braşov, Faculty of Silviculture and Forest Engineering, Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Şirul Beethoven no. 1, 500123, Braşov, Romania ORCID ID:E-mail: ciuboarc@unitbv.ro
article id 1689, category Research article
Juha Laitila, Eeva Lehtonen, Tapio Ranta, Perttu Anttila, Saija Rasi, Antti Asikainen. (2016). Procurement costs of cereal straw and forest chips for biorefining in South-East Finland. Silva Fennica vol. 50 no. 5 article id 1689. https://doi.org/10.14214/sf.1689
Highlights: Procurement cost at the plant was 59 € dry tonne –1 when the annual procurement volume of biomass was 100 000 tonnes. Of that amount, the proportion of logging residues was 58.4%, stumps 24.3% and delimbed stems 17.3%; Cereal straw represents an important source of biomass in Kouvola but the cost competiveness is poor compared the procurement costs of forest chips due to high baling and transporting costs.

In Finland the increasing use of biofuel in transport presupposes a search for new raw material sources for biorefining. The aim of this study was, at the regional level, to compare the procurement costs of logging residues, stumps, delimbed stems and cereal straw for biorefining. The accumulation and procurement costs of forest chips and cereal straw were estimated within a 100-kilometre transporting distance via existing road network from an end-use-facility located in Kouvola in South-East Finland. The analyses were performed as simulated treatments in thinnings of young stands, cereal fields and regeneration fellings using existing productivity and cost functions and yield calculations based on crop statistics, the forest industry stand data and the sample plots data of the National Forest Inventory of Finland. Accumulation of raw material assortments and costs of production stages were defined per dry tonnes. Subsidies and raw material prices were excluded from consideration in the study. The results indicate that recovering logging residues requires lower costs than utilization of stumps, delimbed stems or cereal straw. Cereal straw represents an important source of biomass in Kouvola but the cost competiveness is poor compared the procurement costs of forest chips. When the annual procurement volume of biomass was 50 000 dry tonnes the cost at the plant was 49 € dry tonne –1 and biomass was comprised totally of logging residues. Procurement cost grew to 59 € dry tonne –1 when the annual procurement volume of biomass was doubled to 100 000 dry tonnes. Of that amount, the proportion of logging residues was 58.4%, stumps 24.3% and delimbed stems 17.3%. First cereal straw dry tonnes were delivered to end-use-facility, when procurement cost grew to 60 € dry tonne –1 and annual procurement volume of biomass was 110 000 dry tonnes.

  • Laitila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: juha.laitila@luke.fi (email)
  • Lehtonen, Natural Resources Institute Finland (Luke), Green Technology, Halolantie 31A, FI-71750 Maaninka, Finland ORCID ID:E-mail: eeva.lehtonen@luke.fi
  • Ranta, Lappeenranta University of Technology, LUT School of Energy Systems, Laboratory of Bioenergy, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland ORCID ID:E-mail: tapio.ranta@luke.fi
  • Anttila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: perttu.anttila@luke.fi
  • Rasi, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, Survontie 9A, FI-40500 Jyväskylä ORCID ID:E-mail: saija.rasi@luke.fi
  • Asikainen, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: antti.asikainen@luke.fi
article id 1280, category Research article
Juha Laitila, Tapio Ranta, Antti Asikainen, Eero Jäppinen, Olli-Jussi Korpinen. (2015). The cost competitiveness of conifer stumps in the procurement of forest chips for fuel in Southern and Northern Finland. Silva Fennica vol. 49 no. 2 article id 1280. https://doi.org/10.14214/sf.1280
Highlights: Pre-grinding and integrated screening is a way of guaranteeing fuel quality, but, when the stumps’ ash content is six per cent or below, the procurement costs are higher than with grinding of stumps at the plant. Because of high transportation costs, stump harvesting is the most profitable in Southern Finland, where there is greater availability of stumps than in Northern Finland.
The aim of this study was to evaluate cost competitiveness, at regional level, of various systems for stump transportation and grinding, and to compare the results to the procurement costs of delimbed stems from early thinnings at the stand and regional level. The accumulation and procurement costs of stumps and delimbed stems were estimated within a 100-kilometer radius from two power plants located in Kouvola and in Kajaani. The analyses were performed as simulated treatments in clear cuts and thinnings of young stands, using existing productivity and cost functions, alternative ash percentages for stump wood, and yield calculations based on the forest industry regeneration felling stand data and the sample plots data of the National Forest Inventory of Finland. The results were expressed as Euros per solid cubic meter (€ m–3) and Euros per megawatt hour (€ MWh–1). The results highlight the need to improve stump fuel quality and increase the heating value. The procurement cost of stumps was about 1 € MWh–1 lower in Kouvola compared to Kajaani, when using conceivable ash content of 6% for stumps ground at the plant, and ash content of 1.5% for stumps pre-ground at the roadside landing. The procurement costs of stumps were, on average, 0.55 € MWh–1 lower compared to delimbed stems in Kouvola, and on average 0.6 € MWh–1 higher in Kajaani. Pre-grinding and integrated screening is a feasible way to guarantee the fuel quality expressed as ash content already at roadside landings, but the procurement costs are higher compared to grinding stumps at the plant, when the ash content of ground stumps is 6% or less.
  • Laitila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: juha.laitila@metla.fi (email)
  • Ranta, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: tapio.ranta@lut.fi
  • Asikainen, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: antti.asikainen@metla.fi
  • Jäppinen, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: eero.jappinen@lut.fi
  • Korpinen, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: olli-jussi.korpinen@lut.fi
article id 1047, category Research article
Kalle Karttunen, Lauri Lättilä, Olli-Jussi Korpinen, Tapio Ranta. (2013). Cost-efficiency of intermodal container supply chain for forest chips. Silva Fennica vol. 47 no. 4 article id 1047. https://doi.org/10.14214/sf.1047
Highlights: The combined availability and simulation study method obtains more realistic results for use in practical decision-making in supply chain management; The total costs of forest chips with intermodal composite container supply chains were lower than traditional options in all scenarios; The most advantageous way to expand the procurement area for forest chips is either to use composite container trucks or start using train transportation instead of trucks for procurement from longer distances.
Cost-efficient solutions of supply chains for energy wood are required as part of endeavors to reach targets for renewable energy utilization. Long-distance railway transportation is an interesting area of research, especially for high-volume sites where the forest-to-site distance is considerable and rail facilities already exist. The aim of the study was to compare the cost-efficiency of an intermodal container supply chain and traditional multi-modal supply chain with corresponding direct truck logistics for long-distance transportation of forest chips. In the study, site-dependent information for forest biomass transport was integrated into a simulation model to calculate the cost-efficiency of logistic operations related to forest chips transportation in central Finland. The model was tested with several truck and railway transportation scenarios for varying demand of forest chips at the case power plant. The total costs of traditional supply chains were found to be 5–19% more expensive than container supply chain scenarios. The total unit costs of forest chips varied between 15.3 and 20.0 €/MWh depending on the scenario. It is concluded on the basis of the scenario study that intermodal light-structure container logistics and railway transportation could be developed as a viable option for large-scale supply of forest chips.
  • Karttunen, Lappeenranta University of Technology, LUT Savo Sustainable Technologies, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: kalle.karttunen@lut.fi (email)
  • Lättilä, Lappeenranta University of Technology, LUT Savo Sustainable Technologies, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: lauri.lattila@lut.fi
  • Korpinen, Lappeenranta University of Technology, LUT Savo Sustainable Technologies, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: olli-jussi.korpinen@lut.fi
  • Ranta, Lappeenranta University of Technology, LUT Savo Sustainable Technologies, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: tapio.ranta@lut.fi
article id 88, category Research article
Seppo Rouvinen, Jari Kouki. (2011). Tree regeneration in artificial canopy gaps established for restoring natural structural variability in a Scots pine stand. Silva Fennica vol. 45 no. 5 article id 88. https://doi.org/10.14214/sf.88
In Finland and elsewhere in Europe, many protected forest areas include also stands that were previously managed and that lack several naturally occurring stand characteristics. In these areas, ecosystem restoration can be used to facilitate and accelerate the formation of structural and habitat features resembling those of natural forests. For example, by creating small gaps it could be possible to diversify forest structure and tree species composition and to produce dead wood while still maintaining mostly continous canopy coverage. We examined experimentally the effects of artificial gap formation on post-disturbance tree regeneration in the gaps in a young protected, but formerly commercially managed pine (Pinus sylvestris L.) dominated forest. In the experimental sites, gap size and the portion of girdled trees out of all treated trees (girdled and felled trees combined) in the gaps varied. Natural and artificial (direct seeding of silver birch Betula pendula Roth) tree regeneration and development was monitored both on disturbed (scarified soil patches) and undisturbed forest floor during three growing seasons. Results show that gaps can be valuable in diversifying stand structure but to be successful and rapid, tree regeneration needs disturbed forest floor. Pine regenerated numerously, but birch had clearly lower regeneration, especially on small-sized gaps. In conclusion, increasing tree diversity in young pine-dominated forests seems to be difficult when only small artificial gaps are used. But even small gaps can be used to create and maintain diverse cohort structure of the dominant species and thus they can contribute to restoration goals.
  • Rouvinen, University of Eastern Finland, School of Forest Sciences, Joensuu, Finland ORCID ID:E-mail: seppo.rouvinen@uef.fi (email)
  • Kouki, University of Eastern Finland, School of Forest Sciences, Joensuu, Finland ORCID ID:E-mail:
article id 491, category Research article
Lars Rytter, Lars-Göran Stener. (2003). Clonal variation in nutrient content in woody biomass of hybrid aspen (Populus tremula L. x P. tremuloides Michx.). Silva Fennica vol. 37 no. 3 article id 491. https://doi.org/10.14214/sf.491
Differences in the nutrient concentrations and nutrient amounts of stems and branches amongst clones of hybrid aspen (Populus tremula L. x P. tremuloides Michx.) were investigated. Seven clones with superior and seven with medium growth rates were selected from a test of 119 clones in southern Sweden. Four trees per clone were randomly identified and harvested in dormant conditions. Sample discs from the stems and branches were collected and analysed for N, K, P, Ca, Mg, and S concentrations, as well as wood density. The analyses revealed significant genetic differences in wood density, K, P, and Mg concentrations in the stems. There were weak (non-significant) and negative genetic correlations between stem volume and concentrations of all the nutrients, except potassium, suggesting that nutrient-efficient clones could be selected without significantly sacrificing genetic gain for growth. In the branches K, Ca, and Mg concentrations differed significantly among clones. After selecting more nutrient efficient clones, the potential savings of nutrients compared with current hybrid aspen material was estimated to be around 5%, which seems fairly low, at least in a short-term perspective. However, the use of clones with different nutrient storage strategies may be regarded as a possible way in the long run to save nutrients in hybrid aspen ecosystems, or of removing them when sludge is applied.
  • Rytter, Forestry Research Institute of Sweden, Skogforsk, Ekebo 2250, SE-26890, Svalöv, Sweden ORCID ID:E-mail: lars.rytter@skogforsk.se (email)
  • Stener, Forestry Research Institute of Sweden, Skogforsk, Ekebo 2250, SE-26890, Svalöv, Sweden ORCID ID:E-mail:
article id 510, category Research article
Helge Dzierzon, Risto Sievänen, Winfried Kurth, Jari Perttunen, Branislav Sloboda. (2003). Enhanced possibilities for analyzing tree structure as provided by an interface between different modelling systems. Silva Fennica vol. 37 no. 1 article id 510. https://doi.org/10.14214/sf.510
In recent years, many different advanced mathematical models and simulation systems for tree and forest growth have been developed. We show a possibility to extend analysis tools for measured and simulated plants using a data interface between the simulation model LIGNUM and the multifunctional software system GROGRA. Both systems were developed by different teams. To demonstrate the enhanced possibilities for analyzing a LIGNUM tree, several examples are given. In these examples three different approaches for analysis are applied to measured and simulated trees: Fractal dimension, deduction of tapering laws, and water potential patterns obtained from simulation of waterflow by the specialized software HYDRA. Conclusions for the interfacing and comparison of different modelling tools are drawn.
  • Dzierzon, Institut für Forstliche Biometrie und Informatik, Universität Göttingen, Büsgenweg 4, D-37077 Göttingen, Germany ORCID ID:E-mail: hdzierz@gwdg.de (email)
  • Sievänen, The Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail:
  • Kurth, Institut für Informatik, Brandenburgische Technische Universität Cottbus, P.O. Box 101344, D-03013 Cottbus, Germany ORCID ID:E-mail:
  • Perttunen, The Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail:
  • Sloboda, Institut für Forstliche Biometrie und Informatik, Universität Göttingen, Büsgenweg 4, D-37077 Göttingen, Germany ORCID ID:E-mail:

Category: Review article

article id 9984, category Review article
Christoph Kogler, Peter Rauch. (2018). Discrete event simulation of multimodal and unimodal transportation in the wood supply chain: a literature review. Silva Fennica vol. 52 no. 4 article id 9984. https://doi.org/10.14214/sf.9984
Highlights: Focus on discrete event simulation, wood supply chain and multimodal transport; Analyses of 12 review articles and a core of 32 research papers, complemented by 48 related ones; Research focus from unimodal to multimodal transport to build efficient, resilient, green and socially sustainable supply chains; Development of robust risk management considering supply risks, demand risks and external risks is needed.

This review systematically analyses and classifies research and review papers focusing on discrete event simulation applied to wood transport, and therefore illustrates the development of the research area from 1997 until 2017. Discrete event simulation allows complex supply chain models to be mapped in a straightforward manner to study supply chain dynamics, test alternative strategies, communicate findings and facilitate understanding of various stakeholders. The presented analyses confirm that discrete event simulation is well-suited for analyzing interconnected wood supply chain transportation issues on an operational and tactical level. Transport is the connective link between interrelated system components of the forest products industry. Therefore, a survey on transport logistics allows to analyze the significance of entire supply chain management considerations to improve the overall performance and not only one part in isolation. Thus far, research focuses mainly on biomass, unimodal truck transport and terminal operations. Common shortcomings identified include rough explanations of simulation models and sparse details provided about the verification and validation processes. Research gaps exist concerning simulations of entire, resilient and multimodal wood supply chains as well as supply and demand risks. Further studies should expand upon the few initial attempts to combine various simulation methods with optimization.

  • Kogler, Institute of Production and Logistics, Department of Economics and Social Sciences, University of Natural Resources and Life Sciences, Vienna, Feistmantelstrasse 4, A-1180 Vienna, Austria ORCID ID: https://orcid.org/0000-0001-8811-152X E-mail: christoph.kogler@boku.ac.at (email)
  • Rauch, Institute of Production and Logistics, Department of Economics and Social Sciences, University of Natural Resources and Life Sciences, Vienna, Feistmantelstrasse 4, A-1180 Vienna, Austria ORCID ID: http://orcid.org/0000-0002-5812-4415 E-mail: peter.rauch@boku.ac.at

Category: Research note

article id 7771, category Research note
Māra Kitenberga, Roberts Matisons, Āris Jansons, Jānis Donis. (2018). Teleconnection between the Atlantic sea surface temperature and forest fires in Latvia and Estonia. Silva Fennica vol. 52 no. 1 article id 7771. https://doi.org/10.14214/sf.7771
Highlights: Forest fire activity in Latvia and Estonia was related to conditions in the Atlantic; Teleconnections differed regionally; Negative correlation between number of fires in Estonia and SST in the North Atlantic was detected; Area of forest fires in Estonia and activity of fires in Latvia were positively correlated with SST in the Baltic, North and Mediterranean Seas in summer.

Forest fire is one of the natural disturbances, which have important ecological and socioeconomical effect. Although fire activity is driven by weather conditions, during past two centuries forest fires have been strongly anthropogenically controlled. In this study, teleconnection between sea surface temperature (SST) in the Atlantic, which influences climate in Europe, and forest fire activity in Latvia and Estonia was assessed using “Climate explorer” web-tool. Factors affecting number and area of forest fires in Latvia and Estonia differed, suggesting regional specifics. In Estonia, the number of fires correlated with the SST in the North Atlantic in spring and summer, which affects the inflow of cool and dry air masses from the Arctic, hence the aridity and burnability. The area of fires in Estonia and in Latvia was associated with increased SST in Baltic Sea and near the European coast in summer, which likely were consequences of occurrence of warm high-pressure systems in summer, causing hot and dry conditions. Nevertheless, the observed teleconnections could be used to predict activity of forest fires in Latvia and Estonia.

  • Kitenberga, Latvian State Forest Research Institute ‘Silava’, Rigas st. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: mara.kitenberga@gmail.com (email)
  • Matisons, Latvian State Forest Research Institute ‘Silava’, Rigas st. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: robism@inbox.lv
  • Jansons, Latvian State Forest Research Institute ‘Silava’, Rigas st. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: aris.jansons@silava.lv
  • Donis, Latvian State Forest Research Institute ‘Silava’, Rigas st. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: janis.donis@silava.lv
article id 897, category Research note
Lars Lundqvist, Susanne Spreer, Christer Karlsson. (2013). Volume production in different silvicultural systems for 85 years in a mixed Picea abies–Pinus sylvestris forest in central Sweden. Silva Fennica vol. 47 no. 1 article id 897. https://doi.org/10.14214/sf.897
A long-term comparison of different silvicultural systems was established in 1923 in central Sweden, in an uneven-aged mixed Norway spruce–Scots pine forest (Picea abies (L.) Karst. – Pinus sylvestris L.) with about 85% spruce and 15% pine. The five treatments consisted of two examples of even-aged management 1) clear-cutting followed by planting, and 2) seed tree regeneration, one uneven-aged management 3) selection system, one exploiting treatment 4) diameter limit cut, and 5) one untreated control plot. Each treatment plot was 1 ha, 100 m × 100 m. The plots were measured and managed at irregular intervals, ranging from 7 to 15 years. In 2007–2008 the even-aged treatments and the diameter limit cut were repeated and a new rotation started. Mean annual volume increment during the whole observation period differed widely between the treatments, partly because of differences in species composition over time, with treatment clear-cutting followed by planting at the top, and the control at the bottom. Treatment selection system gave only about 60% of planting, but this was probably largely an effect of too small growing stock during the first roughly 50 years. When the growing stock was increased, periodic annual volume increment increased to about 80% of the mean annual volume increment in the even-aged, planted plot.
  • Lundqvist, Deparment of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden ORCID ID:E-mail: lars.lundqvist@slu.se (email)
  • Spreer, Sveaskog Förvaltnings AB, Ljusdal, Sweden ORCID ID:E-mail: susanne.spreer@sveaskog.se
  • Karlsson, Field Research Unit, Swedish University of Agricultural Sciences, Siljansfors, Sweden ORCID ID:E-mail: christer.karlsson@slu.se
article id 61, category Research note
Janine Schweier, Gero Becker. (2012). Harvesting of short rotation coppice – harvesting trials with a cut and storage system in Germany. Silva Fennica vol. 46 no. 2 article id 61. https://doi.org/10.14214/sf.61
Short rotation coppice (SRC) harvesting techniques are available in Germany, but broad experience and knowledge about machine performance and the related effective costs of harvesting operations are still missing. This information is crucial, as harvesting costs strongly influence the economic performance of the overall supply chain. Therefore, it was the aim of this study to collect and analyze productivity data of different harvesting systems for SRC. The combined cut and chip system on the one hand and the cut and storage system on the other hand were studied by literature review. Several studies analyze the combined cut and chip systems and the reported machine productivities showed great variations. The average was 30 green tons per scheduled machine hour (gt smh–1). Few studies are analysing the cut and storage system. They report that machines still are under development and that further research is needed. Therefore, time studies of harvesting operations using the cut and storage system were carried out. Five trials were performed with the harvesting machine “Stemster MK III” developed by Nordic Biomass. The share of productive working time was 85% and the average productivity was 21 gt smh–1. These results were compared with values from the literature. Resulting harvesting costs were calculated per oven dry ton (euros odt–1). The advantages and disadvantages of both harvesting systems are highlighted.
  • Schweier, Albert-Ludwigs-University Freiburg, Institute of Forest Utilisation and Work Science, Freiburg, Germany ORCID ID:E-mail: janine.schweier@fobawi.uni-freiburg.de (email)
  • Becker, Albert-Ludwigs-University Freiburg, Institute of Forest Utilisation and Work Science, Freiburg, Germany ORCID ID:E-mail:

Category: Discussion article

article id 270, category Discussion article
Seppo Rouvinen, Jari Kouki. (2008). The natural northern European boreal forests: unifying the concepts, terminologies, and their application. Silva Fennica vol. 42 no. 1 article id 270. https://doi.org/10.14214/sf.270
Recent emphasis on conserving the biodiversity has stressed the value of natural ecosystems in saving the species from extinction. In the Fennoscandian region the conifer-dominated boreal forests form the largest single ecosystem. The forests have been under varying intensity of human influence for decades or centuries. Recent attempts have tried to seek the last remaining natural forests to be included in the protection programmes. However, due to long and widespread human influence, finding and defining the natural forests has proven to be extremely difficult, not only because they are so rare but also because the concept of natural forest is vague. These difficulties are partly seen through the diverse terminology used. We first review the varying terminology as seen in recent studies. Secondly, we propose the basis for defining the natural forest and show some intriguing and challenging difficulties are involved in the concept. These difficulties are at least partly related to inherent strong and long-term dynamic component in boreal forest ecosystems that is manifested over several temporal and spatial scales. Finally, we outline a more general terminology with associated indicators and measurements that might be used in the classification and terminology. Conceptual clarification is necessary, for example, to compile ecologically justified and representative global, national and regional forest statistics. Many currently applied definitions of “forest” and “natural” that are applied in the context of forest statistics overlook ecologically important components of natural forests, and thus provide quite misleading or inadequate data of existing diversity patterns in these ecosystems.
  • Rouvinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail:
  • Kouki, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: jari.kouki@joensuu.fi (email)

Category: Article

article id 7264, category Article
P. Kokkonen. (1931). Untersuchungen über die Wurzeln der Getreidepflanzen I: Die Wurzelformen, ihr Bau, ihre Aufgabe und Lage im Wurzelsystem. Acta Forestalia Fennica vol. 37 no. 2 article id 7264. https://doi.org/10.14214/aff.7264
English title: Studies on the root systems of cereals I: the Root form, their structure, function and position in root system.
English keywords: cereals; root systems; function; rye; oat; wheat; barley

Knowledge on the roots systems and their properties is needed when for example assessing the wintering properties of a plant. The article presents the studies on the roots and their functions made with rye, wheat, oat and barley.

The data has been collected during the whole growing season. The experiments took place in the green houses of the University of Helsinki and on the experiment field in Tikkurila, some kilometres north from Helsinki.

The roots of cultivable crop can be divided according their function, state of development, structure and position in the root system into four classes. The classes are sprouting roots, nutriment roots, nutriment-support roots and support roots.

The PDF contains a summary in Finnish. 

  • Kokkonen, ORCID ID:E-mail:
article id 5637, category Article
Janne Uuttera, Harri Hyppänen. (1997). Relationship between forest management planning units and spatial distribution of forest habitat components in Koli National Park. Silva Fennica vol. 31 no. 4 article id 5637. https://doi.org/10.14214/sf.a8539

This study examined the relationships between forest management planning units and patches formed by forest habitat components. The test area used was a part of Koli National Park in North Karelia, eastern Finland. Forest management planning units (i.e. forest compartments) were defined by using a traditional method of Finnish forestry which applies aerial photographs and compartment-wise field inventory. Patches of forest habitat components were divided according to subjective rules by using a chosen set of variables depicting the edaphic features and vegetation of a forest habitat. The spatial distribution of the habitat components was estimated with the kriging-interpolation based on systematically located sample plots. The comparisons of the two patch mosaics were made by using the standard tools of GIS. The results of the study show that forest compartment division does not correlate very strongly with the forest habitat pattern. On average, the mean patch size of the forest habitat components is greater and the number of these patches lower compared to forest compartment division. However, if the forest habitat component distribution had been considered, the number of the forest compartments would have at least doubled after intersection.

  • Uuttera, ORCID ID:E-mail:
  • Hyppänen, ORCID ID:E-mail:
article id 5634, category Article
Leena Finér, Mika Nieminen. (1997). Dry mass and the amounts of nutrients in understorey vegetation before and after fertilization on a drained pine bog. Silva Fennica vol. 31 no. 4 article id 5634. https://doi.org/10.14214/sf.a8536

Dry mass and nutrient (N, P, K, Ca, Mg, B) contents of field layer vegetation and a combination of bottom layer vegetation and litter (referred to as bottom/litter layer in the text) were studied one year before and three years after fertilization (NPK and PK) on a drained low-shrub pine bog in eastern Finland. The results of an earlier study on the tree layer were combined with those of this study in order to estimate the changes caused by fertilization in the total plant biomass and litter. Before fertilization the average dry mass of the field and bottom/litter layers was 8,400 kg ha-1 and 7,650 kg ha-1, respectively. The above-ground parts accounted for 25% of the total field layer biomass. The dry mass of the field and bottom/litter layers together was < 20% of the dry mass accumulated in the total plant biomass and litter. The corresponding figures for N, P, K, Ca, Mg and B were 44%, 38%, 30%, 38%, 31% and 17%, respectively. Fertilization did not significantly affect the dry mass of either the field layer vegetation or the bottom/litter layer. 33% of the applied P was accumulated in the total plant biomass and litter on the PK-fertilized plots, and 25% on the NPK-fertilized plots. For the other elements, the proportions on the PK-fertilized plots were K 31%, Ca 6%, Mg 11% and B 13%. On the NPK-fertilized plots, the corresponding figures were N 62%, K 32%, Ca 6%, Mg 9% and B 13%. Except for B and K, the accumulation of fertilizer nutrients in the understorey vegetation and litter was of the same magnitude or greater than the uptake by the tree layer.

  • Finér, ORCID ID:E-mail:
  • Nieminen, ORCID ID:E-mail:
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

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, ORCID ID:E-mail:
  • Sloboda, ORCID ID:E-mail:
article id 5619, category Article
Pertti Harstela. (1997). Decision support systems in wood procurement. A review. Silva Fennica vol. 31 no. 2 article id 5619. https://doi.org/10.14214/sf.a8520

Many kinds of planning systems have been labelled decision support systems (DSS), but few meet the most important features of real DSSs in planning and control of wood procurement. It has been concluded that many reasons exist to develop DSSs for wood procurement. The purchasing of timber seems to be one of the most promising areas for DSS, because there is no formal structure for these operations and decisions deal with human behaviour. Relations between DSSs and different features of the new approaches in wood procurement are also discussed, and hypotheses for future studies suggested.

  • Harstela, ORCID ID:E-mail:
article id 5590, category Article
Heikki Hänninen, Seppo Kellomäki, Ilkka Leinonen, Tapani Repo. (1996). Overwintering and productivity of Scots pine in a changing climate. Silva Fennica vol. 30 no. 2–3 article id 5590. https://doi.org/10.14214/sf.a9235

The productivity of Scots pine (Pinus sylvestris L.) under changing climatic conditions in the southern part of Finland was studied by scenario analysis with a gap-type forest ecosystem model. Standard simulations with the model predicted an increased rate of growth and hence increased productivity as a result of climatic warming. The gap-type model was refined by introducing an overwintering sub-model describing the annual growth cycle, frost hardiness, and frost damage of the trees. Simulations with the refined gap-type model produced results conflicting with those of the standard simulation, i.e., drastically decreased productivity caused by mortality and growth-reducing damage due to premature dehardening in the changing climate. The overwintering sub-model was tested with frost hardiness data from Scots pine saplings growing at their natural site 1) under natural conditions and 2) under elevated temperature condition, both in open-top chambers. The model predicted the frost hardiness dynamics quite accurately for the natural conditions while underestimating the frost hardiness of the saplings for the elevated temperature conditions. These findings show that 1) the overwintering sub-model requires further development, and 2) the possible reduction of productivity caused by frost damage in a changing climate is less drastic than predicted in the scenario analysis. The results as a whole demonstrated the need to consider the overwintering of trees in scenario analysis carried out with ecosystem model for boreal conditions. More generally, the results revealed a problem that exists in scenario analysis with ecological models: the accuracy of a model in predicting the ecosystem functioning under present climatic condition does not guarantee the realism of the model, nor for this reason the accuracy for predicting the ecosystem functioning under changing climatic conditions. This finding calls for the continuous rigorous experimental testing of ecological models used for assessing the ecological implications of climatic change.

  • Hänninen, ORCID ID:E-mail:
  • Kellomäki, ORCID ID:E-mail:
  • Leinonen, ORCID ID:E-mail:
  • Repo, ORCID ID:E-mail:
article id 5579, category Article
F.G. Hall, P.J. Sellers, D.L. Williams. (1996). Initial results from the boreal ecosystem-atmosphere experiment, BOREAS. Silva Fennica vol. 30 no. 2–3 article id 5579. https://doi.org/10.14214/sf.a9224

BOREAS is a four-year, regional-scale experiment to study the forested continental interior of Canada. It aims at improving our understanding of the interaction between the earths' climate system and the boreal forests at short and intermediate time scales, in order to clarify their role in global change.

During the winter, spring and summer of 1994, five field campaigns were conducted. About 85 investigation teams including nearly 300 scientists participated, including forest ecologists and ecophysiologists, atmospheric physicists, boundary-layer meteorologists, hydrologists, biochemists, atmospheric chemists and remote sensing specialists.

The findings so far have been significant in terms of their implication for global change. The boreal ecosystem, occupying roughly 17 percent of the vegetated land surface and thus an important driver of global weather and climate, absorbs much more solar energy than is assumed by operational numerical weather prediction models. Albedo measurement show that this forest absorbs nearly 91% of the sun's incident energy. Additionally, while it is known that much of the boreal ecosystems consists of forested wetlands, lakes, bogs and fens, the measurements show that the atmosphere above was extremely dry; humidity and deep boundary layer convection (3,000 m) mimicked conditions found only over deserts. Physiological measurements of the trees show that this atmospheric desiccation was a result of the forests' strong biological control limiting surface evaporation. This tight control was linked to the low soil temperature and subsequently reduced rates of photosynthesis. BOREAS measurement also focused on net ecosystem carbon exchange. Data acquired during the late spring and summer, showed the boreal forests to be a net carbon sink. However, no measurements were taken in the early spring following thaw, and in the late fall, where the balance between photosynthesis and respiration is poorly understood. During 1996 additional data will be acquired to resolve the annual carbon budget and how it might depend on interannual climate differences.

  • Hall, ORCID ID:E-mail:
  • Sellers, ORCID ID:E-mail:
  • Williams, ORCID ID:E-mail:
article id 5526, category Article
Pertti. Hari, Pasi Aalto, Kaarle Hämeri, Markku. Kulmala, Tapani. Lahti, Sari. Luoma, Lauri Palva, Toivo Pohja, Erkki. Pulliainen, Erkki. Siivola, Timo Vesala. (1994). Air pollution in eastern Lapland : challenge for an environmental measurement station. Silva Fennica vol. 28 no. 1 article id 5526. https://doi.org/10.14214/sf.a9160

The Värriö environmental measurement station has been designed and constructed during 1991 and 1992. The measurement system consists of measurement units for gases (sulphur dioxide, ozone, carbon dioxide), particles, photosynthesis and irradiation. A meteorological station is also included. The preliminary measurement period was started on August, 1991. During the first year (1991–1992) some parts of the system were redeveloped and rebuilt. Full, continuous measurement started in August 1992. The system has been working quite reliably, with good accuracy. The preliminary results show that pollution episodes are observed when the wind direction is from Monchegorsk or Nikel, the main emission sources in Kola Peninsula.

  • Hari, ORCID ID:E-mail:
  • Aalto, ORCID ID:E-mail:
  • Hämeri, ORCID ID:E-mail:
  • Kulmala, ORCID ID:E-mail:
  • Lahti, ORCID ID:E-mail:
  • Luoma, ORCID ID:E-mail:
  • Palva, ORCID ID:E-mail:
  • Pohja, ORCID ID:E-mail:
  • Pulliainen, ORCID ID:E-mail:
  • Siivola, ORCID ID:E-mail:
  • Vesala, ORCID ID:E-mail:
article id 5512, category Article
Christian Messier, Pasi Puttonen. (1993). Coniferous and non-coniferous fine-root and rhizome production in Scots pine stands using the ingrowth bag method. Silva Fennica vol. 27 no. 3 article id 5512. https://doi.org/10.14214/sf.a15673

Coniferous and non-coniferous fine root and rhizome production was measured after one growing season using the ingrowth bag method in Scots pine (Pinus sylvestris L.) stands differing in ages from 7 to 105 years in Southern Finland. Total fine-root production decreased from the 7-year to 20-year-old stands, and then increased slightly in the 85- to 105-year-old stands. Most of the total fine-root biomass in the youngest age groups came from non-conifer species, whereas most of the total fine-root biomass in the three older age groups came from conifer species. The maximum coniferous fine-root production was found to occur at crown closure in the 11- to 13-year-old stands. Rhizome production was the lowest and highest in the 20- and 85- to 105-year-old stands, respectively. The increase in rhizome production in the 85- to 105-year-old stands was associated with an abundant understory cover of Vaccinium myrtillus and V. vitis-idaea and an increase in light penetration. The ingrowth bag method was found to be useful in assessing the relative fine-root production among species-group and successional stages of Scots pine stands.

The PDF includes an abstract in Finnish.

  • Messier, ORCID ID:E-mail:
  • Puttonen, ORCID ID:E-mail:
article id 5504, category Article
Heli Peltola, Seppo Kellomäki. (1993). A mechanistic model for calculating windthrow and stem breakage of Scots pines at stand age. Silva Fennica vol. 27 no. 2 article id 5504. https://doi.org/10.14214/sf.a15665

A model for the mechanism of windfall and stem breakage was constructed for single Scots pine (Pinus sylvestris L.) at the stand edge. The total turning moment arising from the wind drag and from the bending of stem and crown was calculated along with the breaking stress of the stem. Similarly, the support given by the root -soil plate anchorage was calculated. Windspeed variation within the crown and the vertical distribution of stem and crown weight were taken into account. Model computations showed that trees having a large height to diameter ratio were subjected to greater risk of falling down or breaking than trees with a small height to diameter ratio. The windspeed required to blow down a tree or break the stem of a tree decreased if the height to diameter ratio or the crown to stem ratio of trees increased.
The PDF includes an abstract in Finnish.

  • Peltola, ORCID ID:E-mail:
  • Kellomäki, ORCID ID:E-mail:
article id 5497, category Article
Pertti Pulkkinen. (1993). Frost hardiness development and lignification of young Norway spruce seedlings of southern and northern Finnish origin. Silva Fennica vol. 27 no. 1 article id 5497. https://doi.org/10.14214/sf.a15658

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

  • Pulkkinen, ORCID ID:E-mail:
article id 5479, category Article
Douglas K. Loh, Hannu Saarenmaa. (1992). Design of integrated forest resource information systems. Silva Fennica vol. 26 no. 2 article id 5479. https://doi.org/10.14214/sf.a15640

Managing forests and other natural resources requires merging of data and knowledge from many fields. Research efforts in many countries have simultaneously aimed at computer applications to help managing the large amounts of data involved and the complexities of decision making. This has invariably led to large integrated systems. An integrated system is software that consists of modules for various tasks in natural resource management, spatial analysis, simulation and optimization, diagnostic reasoning, levels, and communicating with the user.

The paper presents an overview of the need, levels and historical development of integrated systems. Newly emerged technologies, especially object-oriented programming and the X Window System with its associated environment have given new flexibility and transparency to the designs. The client-server architecture is found out as an ideal model for integrated systems. The paper describes an implementation of these ideas, the INFORMS system that supports the information needs of district level forest management planning.

The PDF includes an abstract in Finnish.

  • Loh, ORCID ID:E-mail:
  • Saarenmaa, ORCID ID:E-mail:
article id 5469, category Article
Risto Heikkilä, Kari Löyttyniemi. (1992). Growth response of young Scots pines to artificial shoot breaking simulating moose damage. Silva Fennica vol. 26 no. 1 article id 5469. https://doi.org/10.14214/sf.a15627

The main stem of young Scots pine (Pinus sylvestris L.) trees was cut off halfway along the current leading shoot and the two previous years’ leading shoots to simulate moose (Alces alces) damage. Trees of the same size were chosen as controls before treatments. The experiment was inspected ten years after artificial stem breakage. Removing the current leading shoot and the second shoot did not essentially affect the height and diameter growth of the trees. Removal down to the third shoot reduced the height as well as diameter growth. The average loss in growth was equivalent to less than one year’s growth. When the stem was cut off at the second or third shoot, stem crookedness and the presence of knots resulted in stem defects that will subsequently reduce the sawtimber quality. A high proportion of the stem defects will obviously still be visible at the first thinning cutting. Removing injured trees as pulpwood and pruning the remaining parts of cut stems evidently improves the quality of pine stand with moose damage.

The PDF includes an abstract in Finnish.

  • Heikkilä, ORCID ID:E-mail:
  • Löyttyniemi, ORCID ID:E-mail:
article id 5468, category Article
Seppo Kellomäki, Heikki Hänninen, Taneli Kolström, Risto Lauhanen, Ulla Mattila, Brita Pajari, Hannu Väisänen. (1992). A simulation model for the succession of the boreal forest ecosystem. Silva Fennica vol. 26 no. 1 article id 5468. https://doi.org/10.14214/sf.a15626

A model for the succession of the forest ecosystem is described. The growth and development of trees and ground cover are controlled by temperature and light conditions and the availability of nitrogen and water. In addition, the effects of the annual cycle of trees including the risk of frost damage, wild fire, and wind damages are contained in the model as factors which control the survival and productivity of trees. The model also makes it possible to evaluated the risk of insect attack assuming that this risk is inversely related to the growth efficiency of trees.

The PDF includes an abstract in Finnish.

  • Kellomäki, ORCID ID:E-mail:
  • Hänninen, ORCID ID:E-mail:
  • Kolström, ORCID ID:E-mail:
  • Lauhanen, ORCID ID:E-mail:
  • Mattila, ORCID ID:E-mail:
  • Pajari, ORCID ID:E-mail:
  • Väisänen, ORCID ID:E-mail:
article id 5458, category Article
Jaroslaw Burczyk, Grzegorz Kosiński, Andrzej Lewandowski. (1991).  . Silva Fennica vol. 25 no. 4 article id 5458. https://doi.org/10.14214/sf.a15616
English title: Mating pattern and empty seed formation in relation to crown level of Larix decidua (Mill.) clones.

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

The PDF includes an abstract in Finnish.

  • Burczyk, ORCID ID:E-mail:
  • Kosiński, ORCID ID:E-mail:
  • Lewandowski, ORCID ID:E-mail:
article id 5425, category Article
Hannu Saarenmaa. (1990). Frame- and rule-based knowledge representation in an expert system for integrated management of bark beetles. Silva Fennica vol. 24 no. 2 article id 5425. https://doi.org/10.14214/sf.a15579

Decision making in the forest protection involves diagnosing the pest, making predictions of the effects of the pest on forest, knowing the possible control tactics, and cost/benefit integration. To cope with all that, a generalist forest manager needs a tool like an expert system to support decisions.

This paper presents an expert system that approaches the goals of integrated pest management. With the systm, the user can make diagnosis and predictions of 12 North European bark beetles. Written in Common LISP and Flavors, the expert system has a combined frame- and rule-based knowledge representation. Frames are used to represent the hierarchy of insect taxonomy in diagnosis. Prediction is made with qualitative reasoning with rules. The interface engine applies both forward and backward chaining. The system has a graphical user interface that supports exploring the sensitivity of advice on input.

It is concluded that expert systems and artificial intelligence have high applicability everywhere in forestry where complicated decisions have to be made. Especially, an integrated pest management system in forestry is largely equivalent to a computerized decision-making aid.

The PDF includes an abstract in Finnish.

  • Saarenmaa, ORCID ID:E-mail:
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.

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, ORCID ID:E-mail:
article id 5371, category Article
Riitta Laurila. (1989). Pieniläpimittaisen männyn kuituominaisuudet. Silva Fennica vol. 23 no. 1 article id 5371. https://doi.org/10.14214/sf.a15530
English title: Fibre properties in Pinus sylvestris pulpwood.

Properties of fibres in pulpwood, especially length, width and the thickness of walls in tracheids, are essential for strength properties of pulp and paper. Length and width of tracheids increase from pith to surface in radial direction. Young and small-sized stems have also smaller fibres. Small-sized Pinus sylvestris L. test trees had tracheids that were shorter both in stems and knot wood than those in normal sized trees. However, cell walls in test trees were as thick as in normal sized trees. It seems that especially the L/T -ratio (length/thickness) in small stems is worse than in normal sized pulp wood.

The PDF includes an abstract in English.

  • Laurila, ORCID ID:E-mail:
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

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, ORCID ID:E-mail:
article id 5111, category Article
Seppo Kellomäki. (1981). Effect of the within-stand light conditions on the share of stem, branch and needle growth in a twenty-year-old Scots pine stand. Silva Fennica vol. 15 no. 2 article id 5111. https://doi.org/10.14214/sf.a15052

The share of stem, branch and needle growth was dependent on the within-stand light regime in a young Scots pine (Pinus sylvestris L.) stand. The share of needle growth increased at the expense of stem and branch growth in poor light conditions. In good light condition the share of branch wood increased substantially. The share of stem wood growth was greatest in moderate shading, emphasizing the role of an adequate stand density for growing high-quality timber. The basic density of the stem wood was considerably greater in suppressed trees than in dominating trees. The differences were related to the illumination of the crown system.

The PDF includes a summary in Finnish.

  • Kellomäki, ORCID ID:E-mail:
article id 5025, category Article
Eero Paavilainen. (1979). MAB 2 -projekti Suomessa. Silva Fennica vol. 13 no. 2 article id 5025. https://doi.org/10.14214/sf.a14879
English title: MAB 2 project in Finland.

The article examines the problems of interdisciplinary research and the Finnish participation in MAB Project 2, which concentrates on the influences of man’s activities on forests. From the Finnish point of view, the main research areas are the effects of forestry activities which affect large areas, multiple use of forests, forests and environmental pollution, and the effects of energy economy.

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

The PDF includes a summary in English.

  • Paavilainen, ORCID ID:E-mail:
article id 5023, category Article
Anu Pärnänen. (1979). Erilaisten maankäyttötapojen ja hoitotoimenpiteiden ekologiset vaikutukset metsiin. Silva Fennica vol. 13 no. 2 article id 5023. https://doi.org/10.14214/sf.a14877
English title: Ecological effects of different land uses and management practices on boreal landscapes – Man and the Biosphere Programme, seminar of Project 2.

Man and the Biosphere (MAB) programme of UNESCO was launched in 1970. This interdisciplinary programme represents a new integrated approach to research, training and action aimed at improving man’s partnership with the environment. It consists of 14 project areas.

The Academy of Finland and the Finnish Committee for the MAB, in cooperation with the University of Helsinki and the city of Tampere organized a seminar with an aim of reviewing the execution of the Finnish participation in the MAB project No. 2. The seminar took place at Hyytiälä, a forest research station of the University of Helsinki, on August 24–25 1978.

During the seminar, an excursion was made to Pyynikki esker, a unique natural park close to the centre of the city of Tamper. Eight papers were presented and discussed in the seminar. The papers are published in this issue of Silva Fennica.

The PDF includes a summary in English.

  • Pärnänen, ORCID ID:E-mail:
article id 4943, category Article
Matti Leikola. (1976). Näkökohtia metsikköekologisten ympäristötekijöiden mittaamisesta. Silva Fennica vol. 10 no. 2 article id 4943. https://doi.org/10.14214/sf.a14789
English title: Measuring environmental factors in a forest ecosystem.

In the article some aspects concerning the measurement of environmental factors are discussed. Special attention is given to the following questions: The correct way of determining the active surface in a forest ecosystem, the time factor in measurement processes, and the mutual correlative relationships between the environmental factors. Analysis of the data is also taken into consideration.

The PDF includes a summary in English.

  • Leikola, ORCID ID:E-mail:
article id 4943, category Article
Matti Leikola. (1976). Näkökohtia metsikköekologisten ympäristötekijöiden mittaamisesta. Silva Fennica vol. 10 no. 2 article id 4943. https://doi.org/10.14214/sf.a14789
English title: Measuring environmental factors in a forest ecosystem.

In the article some aspects concerning the measurement of environmental factors are discussed. Special attention is given to the following questions: The correct way of determining the active surface in a forest ecosystem, the time factor in measurement processes, and the mutual correlative relationships between the environmental factors. Analysis of the data is also taken into consideration.

The PDF includes a summary in English.

  • Leikola, ORCID ID:E-mail:
article id 4688, category Article
L. Heikurainen, Finnish Society of Forest Science. (1960). Symposio metsätyypeistä ja metsäekosysteemeistä Motrealissa elokuun 24. päivänä 1959. IX Kansainvälisen kasvitieteellisen kongressin yhteydessä. Silva Fennica no. 105 article id 4688. https://doi.org/10.14214/sf.a14129
English title: Symposium on forest types and forest ecosystems during the IX international botanical congress Montreal, August 24th 1959.

The paper is a review on the topics of Symposium on forest types and forest ecosystems, held in connection to the IX internal botanical congress in Montreal in August 1959, the chairman of which was Ilmari Hustich. The article includes 18 preparatory papers that were distributed among the participants of the symposium. The common theme of the papers was the question of finding common platform for the different schools of forest types and forest ecosystems. In addition to the papers, the article includes a summary of the proceedings and discussions of the symposium.

 

The following papers were presented in the symposium:

Aichinger, E. Können wir eine gemeinsame Platform für die verscheidenen Schulen in der Waldtypenklassifikationen finden?

Arnborg, T. Can we find a common platform for the different schools of forest type classifications?

Dansereau, P. A combined structural and floristic approach to the definition of forest ecosystems.

Daubenmire, R. Some major problems in vegetation classification

Ellenberg, H. Können wir eine gemeinsame Platform für die verscheidenen Schulen in der Waldtypenklassifikationen finden?

Hills, G.A. Comparison of forest ecosystems (vegetation and soil) in different climatic zones

Kalela, A. Classification of the vegetation, especially of the forest, with particular reference to regional problems

Krajina, V.J. Can we find a common platform for the different schools of forest type classifications?

Kühler, A.W. Mapping tropical forest vegetation

Linteau, A. Y. a-t-il. Un terrain d’entente possible entre les différentes écoles au sujet de la classification de types forestiers?

Medvecka-Kornaś, A. Some problems of forest climaxes in Poland

Ovington, J.D. The ecosystem concept as aid to forest classification

Puri, G.S. The concept of climax in forest botany as applied in India

Rowe, J.S. Can we find a common platform for the different schools of forest type classifications?

Scamoni, A. Können wir eine gemeinsame Grundlage für die verscheidenen Schulen in der Waldtypenklassifikationen finden?

Sukachev, V.N. The correlation between the concept ’forest ecosystem’ and ’forest biogeocoenise’ and their importance for the classification of forests

Webb, L.J. A new attempt to classify Australian rain forest

  • Heikurainen, ORCID ID:E-mail:
  • Finnish Society of Forest Science, ORCID ID:E-mail:

Register
Click this link to register for Silva Fennica submission and tracking system.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content
Your selected articles

Committee on Publication Ethics A Trusted Community-Governed Archive