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Silva Fennica vol. 34 no. 2 | 2000

Special issue: Forestry Scenario Modelling in Risk Analysis and Management

Category : Research article

article id 638, category Research article

Gert-Jan Nabuurs, Mart-Jan Schelhaas, Ari Pussinen. (2000). Validation of the European Forest Information Scenario Model (EFISCEN) and a projection of Finnish forests. Silva Fennica vol. 34 no. 2 article id 638. https://doi.org/10.14214/sf.638

Keywords: Finland; EFISCEN; European forests; historic forest inventory data

Abstract | View details | Full text in PDF | Author Info

Large-scale forest scenario models are intensively used to make projections of forest areas of up to hundreds of millions of hectares. Within Europe, such projections have been done for 11 countries at the individual national scale, most often to foresee the long-term implications of the ongoing forest management. However, the validity of the models has rarely been tested. The aim of this study was 1. to validate the European Forest Information SCENario model (EFISCEN) by running it on historic Finnish forest inventory data, 2. to improve the model based on the validation, and 3. to project the Finnish forest development till 2050 with the improved model under alternative scenarios. The results of the validation showed that EFISCEN is capable of making reliable large-scale projections of forest resources for periods up to 50–60 years. Based on the validation, the model was improved concerning simulation of age development, thinning regimes and regrowth after thinning. The projection of the Finnish forests till 2050 with the improved model presented a maximum sustainable felling level of around 70 million m3 per year. That provides an average growing stock of 106 m3 ha–1 in 2050 and a net annual increment of 3.6 m3 ha–1 y–1. If the current trend towards more nature oriented forest management continues and 1.39 million ha of forests have been set aside additionally for nature reserves by 2050, the felling level could meet a realistic demand of 57 million m3 per year in 2050. Under the latter regime the average growing stock will have grown to 160 m3 ha–1 in 2050.

Nabuurs, European Forest Institute (EFI), Torikatu 34, FIN-80100 Joensuu, Finland; Wageningen University and Research Center, ALTERRA, P.O. Box 47, NL 6700 AA Wageningen, The Netherlands E-mail: g.j.nabuurs@alterra.wag-ur.nl
Schelhaas, European Forest Institute (EFI), Torikatu 34, FIN-80100 Joensuu, Finland; Wageningen University and Research Center, ALTERRA, P.O. Box 47, NL 6700 AA Wageningen, The Netherlands E-mail: mjs@nn.nl
Pussinen, European Forest Institute (EFI), Torikatu 34, FIN-80100 Joensuu, Finland; Wageningen University and Research Center, ALTERRA, P.O. Box 47, NL 6700 AA Wageningen, The Netherlands E-mail: ap@nn.nl

article id 637, category Research article

Hirofumi Kuboyama, Hiroyasu Oka. (2000). Climate risks and age-related damage probabilities – effects on the economically optimal rotation length for forest stand management in Japan. Silva Fennica vol. 34 no. 2 article id 637. https://doi.org/10.14214/sf.637

Keywords: simulation; climatic risks; damage probability; age class; optimal rotation period; land expectation value

Abstract | View details | Full text in PDF | Author Info

We estimated the damage probability according to age class and major climatic disasters based on ‘Statistical Yearbook of National Forest Insurance’ from 1960 to 1996. The probability of snow damage is high for young stands, then gradually decreases with age. On the other hand, the risk of wind damage gradually increases with age. Decisions about rotation age should be based on the distribution of damage probability with stand age. Risk of damage has two contradictory effects on the optimal rotation period; one is that the rotation-shortening effect caused by risk of damage around harvest age; another is the rotation-extending effect due to decrease of rent by the risk of damage through the raising period. Change of optimal rotation depends on the relative magnitude of these effects. We examine this by calculating land expectation value (LEV) using a simulation model with the empirical damage probability, price and cost. Change of the optimal rotation period obtained from the national average damage probability is not significant. However, the optimal rotation is shorter in high wind risk areas and is longer in high snow risk areas. It is because the damage probability for a mature stand is high in the case of wind and low in the case of snow. In addition, the extent of decrease in LEV is smaller for wind than for snow. The results of simulation based on empirical data confirm that the optimal rotation period can become either shorter or longer through incorporating risk in decision making, depending on the damage probability distribution with stand age.

Kuboyama, Forestry and Forest Products Research Institute Tohoku Center, Nabeyashiki 72, Shimo-Kuriyagawa, Morioka, Iwate, 020-0123 Japan E-mail: kuboyama@ffpri-thk.affrc.go.jp
Oka, Forestry and Forest Products Research Institute Tohoku Center, Nabeyashiki 72, Shimo-Kuriyagawa, Morioka, Iwate, 020-0123 Japan E-mail: ho@nn.jp

article id 636, category Research article

Tuula Nuutinen, Hannu Hirvelä, Jari Hynynen, Kari Härkönen, Hannu Hökkä, Kari T. Korhonen, Olli Salminen. (2000). The role of peatlands in Finnish wood production – an analysis based on large-scale forest scenario modelling. Silva Fennica vol. 34 no. 2 article id 636. https://doi.org/10.14214/sf.636

Keywords: peatlands; MELA; wood production; forest scenario modelling

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Using the Finnish MELA model, a set of scenarios were produced and used to map the possibilities and risks surrounding the utilisation of peatlands in wood production in Finland. One of the scenarios was an estimate of allowable-cut calculated by maximising the net present value of the future revenues using a four per cent interest rate subject to non-decreasing flow of wood, saw logs and net income over a 50-year period, and net present value after the 50 year period greater or equal than in the beginning. The estimate for maximum regionally sustained removal in 1996–2005 was 68 million m3 per year – approaching 74 million m3 during the next decades. In this scenario, 14 per cent of all cuttings during the period 1996–2005 would be made on peatlands, which comprise ca. 31 per cent of the total area of forestry land. By the year 2025, the proportion of peatland cuttings would increase to over 20 per cent. The increase in future cutting possibilities on peatlands compensated for a temporary decrease in cuttings and growing stock on mineral soils. The allowable-cut effect was especially pronounced in northern Finland, where peatlands play an important role in wood production. In addition, the sensitivity of cutting possibilities for assumptions related to growth and price were analysed. The estimate of maximum sustainable yield as defined here seems to be fairly robust on the whole, except in northern Finland where the cutting scenarios were sensitive to the changes in the price of birch pulpwood. The proportion of peatland stands that are profitable for timber production depends on the interest rate: the higher the rate of interest the less peatland stands are thinned. The effect of cutting profile on future logging conditions and resulting costs were analysed in two forestry centres. If clear cuttings on mineral soils are to be cut first, an increase in future logging costs is inevitable.

Nuutinen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: tuula.nuutinen@metla.fi
Hirvelä, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: hh@nn.fi
Hynynen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: jh@nn.fi
Härkönen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: kh@nn.fi
Hökkä, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: hh@nn.fi
Korhonen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: ktk@nn.fi
Salminen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: os@nn.fi

article id 635, category Research article

Manfred J. Lexer, Karl Hönninger, Helfried Scheifinger, Christoph Matulla, Nikolaus Groll, Helga Kromp-Kolb. (2000). The sensitivity of central European mountain forests to scenarios of climatic change: methodological frame for a large-scale risk assessment. Silva Fennica vol. 34 no. 2 article id 635. https://doi.org/10.14214/sf.635

Keywords: climate change; potential natural vegetation; alpine forests; risk assessment; patch model; multi-attribute decision making

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The methodological framework of a large-scale risk assessment for Austrian forests under scenarios of climatic change is presented. A recently developed 3D-patch model is initialized with ground-true soil and vegetation data from sample plots of the Austrian Forest Inventory (AFI). Temperature and precipitation data of the current climate are interpolated from a network of more than 600 weather stations to the sample plots of the AFI. Vegetation development is simulated under current climate (‘control run’) and under climate change scenarios starting from today's forest composition and structure. Similarity of species composition and accumulated biomass between these two runs at various points in time were used as assessment criteria. An additive preference function which is based on Saaty’s AHP is employed to synthesize these criteria to an overall index of the adaptation potential of current forests to a changing climate. The presented methodology is demonstrated for a small sample from the Austrian Forest Inventory. The forest model successfully simulated equilibrium species composition under current climatic conditions spatially explicit in a heterogenous landscape based on ground-true data. At none of the simulated sites an abrupt forest dieback did occur due to climate change impacts. However, substantial changes occured with regard to species composition of the potential natural vegetation (PNV).

Lexer, Institute of Silviculture, University of Agricultural Sciences, Peter-Jordanstrasse 70, A-1190 Vienna, Austria E-mail: lexer@edv1.boku.ac.at
Hönninger, Institute of Silviculture, University of Agricultural Sciences, Peter-Jordanstrasse 70, A-1190 Vienna, Austria E-mail: kh@nn.at
Scheifinger, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria E-mail: hs@nn.at
Matulla, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria E-mail: cm@nn.at
Groll, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria E-mail: ng@nn.at
Kromp-Kolb, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria E-mail: hkk@nn.at

article id 634, category Research article

Marcus Lindner, Petra Lasch, Markus Erhard. (2000). Alternative forest management strategies under climatic change – prospects for gap model applications in risk analyses. Silva Fennica vol. 34 no. 2 article id 634. https://doi.org/10.14214/sf.634

Keywords: climate change; forest management; adaptation and mitigation strategies; forest succession model; FORSKA

Abstract | View details | Full text in PDF | Author Info

The projected global climate change will influence growth and productivity of natural and managed forests. Since the characteristics of the future regional climate are still uncertain and the response of our forests to changes in the atmospheric and climatic conditions may be both positive or negative, decision making in managed forests should consider the new risks and uncertainties arising from climatic change, especially if the rotation periods are long. An extended version of the forest gap model FORSKA was applied to simulate the forest development at 488 forest inventory plots in the federal state of Brandenburg, Germany, under two climate and three management scenarios. The transient growth dynamics from 1990 to 2100 were investigated at four sites in different parts of the state, representing the variability of environmental and forest conditions within Brandenburg. The alternative management strategies led to distinct differences in forest composition after 110 years of simulation. The projected climate change affected both forest productivity and species composition. The impacts of alternative management scenarios are discussed. It is concluded that the extended forest gap model can be a valuable tool to support decision making in forest management under global change.

Lindner, Potsdam Institute for Climate Impact Research, P.O. Box 60 12 03, D-14412 Potsdam, Germany E-mail: lindner@pik-potsdam.de
Lasch, Potsdam Institute for Climate Impact Research, P.O. Box 60 12 03, D-14412 Potsdam, Germany E-mail: pl@nn.de
Erhard, Potsdam Institute for Climate Impact Research, P.O. Box 60 12 03, D-14412 Potsdam, Germany E-mail: me@nn.de

article id 633, category Research article

Tron Eid. (2000). Use of uncertain inventory data in forestry scenario models and consequential incorrect harvest decisions. Silva Fennica vol. 34 no. 2 article id 633. https://doi.org/10.14214/sf.633

Keywords: forest management; uncertain inventory data; final harvest decisions; expected net present value-losses; inventory planning

Abstract | View details | Full text in PDF | Author Info

Uncertainty in long-term timber production analyses usually focus success of regeneration, growth/mortality of trees and future fluctuations of timber prices/harvest costs, while uncertainty related to inventory data is paid less attention. At the same time, evaluations of inventory methods usually stop when the error level is stated, while the uncertainty accompanied by using the data is seldom considered. The present work addresses uncertain inventory data in long-term timber production analyses. Final harvest decisions, i.e. possible outcome intervals with respect to timing and expected net present value-losses due to incorrect timing, were considered. A case study was presented where inventory data errors according to different error levels were generated randomly. The selected error levels were based on observations from practical forest inventories in Norway. The analysis tool was GAYA-JLP. The impact of errors on decisions was derived through repeated computations of management strategies maximising net present value without harvest path constraints. A real rate of discount of 3% and an error level of 15% resulted in expected net present value-losses of 1 NOK ha–1 for basal area, 63 NOK ha–1 for mean height, 210 NOK ha–1 for site quality, 240 NOK ha–1 for stand age, and 499 NOK ha–1 when random errors occurred simultaneously for all these variables. The expected net present value-losses varied considerably. The largest losses appeared for stands with ages around optimal economical rotation ages. The losses were also relatively large for young stands, while they were relatively low for overmature stands. The experiences from the case study along with considerations related to other sources of uncertainty may help us to get a more realistic attitude to the reliability of long-term timber production analyses. The results of the study may also serve as a starting point in a decision oriented inventory planning concept, in which alternatives for inventory design and intensity are based on considerations with respect to inventory costs as well as net present value-losses.

Eid, Department of Forest Sciences, Agricultural University of Norway, P.O. Box 5044, N-1432 Ås, Norway E-mail: tron.eid@isf.nlh.no

Category : Review article

article id 639, category Review article

Klaus von Gadow. (2000). Evaluating risk in forest planning models. Silva Fennica vol. 34 no. 2 article id 639. https://doi.org/10.14214/sf.639

Keywords: harvest scheduling; continuous cover forest; activity scenario

Abstract | View details | Full text in PDF | Author Info

The purpose of forest scenario modelling is to evaluate multiple management options and to answer what if questions relating to a particular development path of a given forest. Forest scenario planning can reduce uncertainty in management outcomes by anticipating the future in a systematic way, thus reducing the likelihood of unexpected events. It can also improve the chance that future developments will agree with specified objectives. Numerous techniques have been proposed for generating and evaluating scenarios of forest development. Some of the techniques are limited to applications in simple forest production systems while others are suitable for any type of forest management, including individual tree selection systems. Risk is defined as the expected loss due to a particular hazard for a given area and reference period. An expected loss may be calculated as the product of the damage and its probability. Risk analysis, risk evaluation and risk management are formal procedures for quantifying, evaluating and managing risk within a given hazard domain. Applications of risk analysis in forest scenario planning are rare and greater emphasis needs to be placed on hazard prediction. The aim of this contribution is to discuss some aspects of risk analysis, including examples of specific modelling tools. In a forest planning model risk can be considered in the form of specific constraints limiting the total risk in a given time period. Expected hazards can be used to exclude certain risky alternatives and finally, risk can be calculated and used to reduce the value of an objective function coefficient.

Gadow, Georg-August-University Göttingen, Institute for Forest Management, Büsgenweg 5, 37077 Göttingen, Germany E-mail: kgadow@gwdg.de

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