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Forest landscapes are too complex systems for the actors involved in policy making, including experts, to predict the consequences of different management options and policy measures without the aid of modelling tools. Forest sector models and forest management Decision Support Systems (DSS) are two major types of modelling tools that can be used for providing model-based support to forest policy development. Regardless of the modelling tool, policy makers and other concerned actors need to be aware of the behavioral assumptions, or implications, of a scenario in order to proceed to an assessment of what it takes to achieve, alternatively avoid it. A unified method or even a unified understanding of this problem is as yet lacking among forest scenario analysts. This paper presents an approach to facilitate the definition and communication of behavioral assumptions, primarily in DSS-based forest scenario modelling. At the core of the approach is the Behavioral Matrix (BM), a way of structuring forest management specifications. A case study in southern Sweden is presented as an example.

In this paper, we develop an interdisciplinary agent-based framework for studying the provision of forest ecosystem goods and services (ES) at the landscape level. It combines forest owner types and their behavioral models with forest decision support systems (DSS). For this, we draw on mainstream decision-making theories in social sciences and relevant empirical evidence from Europe and beyond to suggest how economic, sociological and psychological rationalities can be combined to build a typology and behavioral models of forest owner decision-making including responsiveness to policy and socioeconomic changes. We then discuss how the theory-driven and evidence-based behavioral models in combination with forest owner and forest management insights can be used to analyze forest management behavior and responsiveness to policy and socioeconomic developments. By comparing standard forest DSS modeling results to exemplary results using the agent-based framework in terms of long-term simulations of timber production and biodiversity conservation in a case study in Sweden, we illustrate how the framework accounts for more differentiated and more realistic forest management practices at the forest landscape level. We discuss how the agent-based framework also helps explore and explain the impacts of future policy and socioeconomic changes on the provision of forest ES. We then suggest directions for future research that can further develop the framework and its use in forest modeling and DSS to better analyze the impact of future developments on forest management and the provision of forest ES at the landscape level.

Forest biomass is a renewable resource that is increasingly utilised for bioenergy purposes in Sweden, which along with the extraction of industrial wood may conflict with biodiversity conservation. The aim of this paper is to present a method for integrated sustainability assessment of forest biomass extraction, particularly from bioenergy and biodiversity perspectives. The landscape simulator LandSim was developed and linked with models for the assessment of biomass yields and habitat networks representing prioritised biodiversity components. It was applied in a case study in Kronoberg County in southern Sweden. Forest growth and management were simulated for the period 2010–2110, following two land zoning scenarios, one applying even-aged forest management on all forest land except for protected areas (EAF-tot), and one applying continuous cover forest management on parts of the forest land, combined with protected areas and an intensified even-aged management on the other parts (CCF-int). The EAF-tot scenario implied higher yields of biomass feedstock for bioenergy, the CCF-int scenario only giving 66% of that yield, while the CCF-int scenario performed substantially better when it came to the habitat network indicators, if habitat suitability was ensured. Conclusively, the case study confirmed that the modelling framework of the LEcA tool, linking the landscape simulator LandSim with the biomass yield assessment and the habitat network model can be used for integrating main policy concerns when assessing renewable energy options.

The FoLDS framework presented in this paper is set up to develop scenarios for forested landscapes with a transparent connection between the broad-scale developments in socio-economic factors and the ecosystem services provided. The forests that provide these ecosystem services are managed by a multitude of forest owners. Different forest owners have their own objectives and will thus adjust their forest management differently to socio-economic developments. The FoLDS framework breaks down the connection from socio-economic developments to the landscape level in three steps. In the first step, a structure is provided for deciding on scenarios combining the socio-economic factors that have most influence on forest owners. In the second step, the scenarios are translated to the distribution of forest management approaches in the landscape by invoking a behavioural matrix of forest owner types and forest management decisions. The third step involves the implementation of these forest management approaches in a forest modelling tool that is tailored to the specific landscape at hand. The results of these calculations are then translated to a set of indicators for the ecosystem services of interest. A survey among researchers experienced with the FoLDS framework indicates that there is an added value in systematically including both qualitative and quantitative scenario methods for forested landscapes.

This paper introduces a modeling approach for the assessment of policy options within the forest-based bioeconomy. The feedback between the forestry dynamics model and the economic model of the global forest-based sector of the proposed framework is essential, not only for response analysis as to the development of forest resources and for a correct assessment of future harvesting potentials, but also for the assessment of the impact of different management regimes on wood-based product markets. Test runs of the modeling framework on a Swedish case highlight the necessity of considering timber assortments for a comprehensive integration of forest resources and wood-based commodity market dynamics. Hence, the composition of harvest demand in terms of timber assortment affects the allocation of harvesting activities and, consequently, the development of forest resources (and thus future harvest potentials), as well as the production, trade and consumption of wood-based products.

In this paper a new concept for modeling uneven-aged forests (UEAF) is presented. The term UEAF in this article encloses all forests that deviate from the even-aged structure. The matrix model is area-based, in that the forest under study is described by a distribution of areas over fixed state-spaces spanned by stem number and volume per hectare classes. Dynamics is introduced as transitions of areas inside the state-space during the simulation. Harvesting activities and the occurrence of calamities are explicitly handled. The model is designed to be suitable for large-scale analyses. The concept was tested in an application to Austrian National Forest Inventory (NFI) data. Results shown, including a comparison to older inventory data, indicate that it is worth further elaborating on the concept and the model. The work will be continued and in the next step the model concept will be applied in several other countries.

Many countries have developed their own systems for projecting forest resources and wood availability. Although studies using these tools are helpful for developing national policies, they do not provide a consistent assessment for larger regions such as the European Union or Europe as a whole. Individual national-scale studies differ considerably in timing, underlying methodology and scenarios, and reports are not issued for all countries in the region. However, a clear demand for consistent projections at European scale still remains. This chapter describes the resource simulators and forest sector models EFISCEN, EFDM, CBM-CFS3, and GLOBIOM/G4M that can all be applied to individual European countries, as well as to Europe as a whole.

For forest sustainability and vulnerability assessment, the landscape scale is considered to be more and more relevant as the stand level approaches its known limitations. This review, which describes the main forest landscape simulation tools used in the 20 European case studies of the European project “Future-oriented integrated management of European forest landscapes” (INTEGRAL), gives an update on existing decision support tools to run landscape simulation from Mediterranean to boreal ecosystems. The main growth models and software available in Europe are described, and the strengths and weaknesses of different approaches are discussed. Trades-offs between input efforts and output are illustrated. Recommendations for the selection of a forest landscape simulator are given. The paper concludes by describing the need to have tools that are able to cope with climate change and the need to build more robust indicators for assessment of forest landscape sustainability and vulnerability. The INTEGRAL project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No. 282887. http://www. integral-project.eu/. Moreover, financial support by the Transnational Access to Research Infrastructures activity in the 7th Framework Programme of the EC under the Trees4Future project (No. 284181) for conducting the research is gratefully acknowledged. This research has also received funding from the European Union H2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 691149 (SuFoRun). Researcher Jordi Garcia-Gonzalo was supported by a “Ramon y Cajal” research contract from the MINECO (Ref. RYC-2013-14262) and has received funding from CERCA Programme/Generalitat de Catalunya. This paper could be achieved thanks to support of EFIATLANTIC donors: Conseil regional d’Aquitaine, Ministère de l’agriculture et de la forêt.

Lithuania and Southern Sweden share similar natural conditions, but differ considerably in forest policies and management; thereby providing an opportune basis for comparative studies. Since the 1990s, Sweden has attempted to reduce the negative impact of its forest management on biodiversity, after decades of intensive production forestry. In contrast, Lithuania has been intensifying forestry practices associated with the post-soviet socio-economic transition. Here we assess the actual outcomes by comparing selected forest structure and composition variables known to be indicators for forest biodiversity; and estimate the prospective trends by scrutinising current forest policies and management. Our results indicate that Lithuanian forests consistently possessed higher rankings in six indices related to tree species composition, stand age, and deadwood quantities that are positively associated with forest biodiversity. The reverse is indicated by those data on stand age and tree diameter that are associated with centennial dynamics in forest utilisation intensity. With respect to policy instruments, Lithuania designates a substantially greater share of forest area to non-timber functions and legislates more severe management restrictions in forests targeting timber production. Concurrently, all estimates of forestry activities indicate more intensive forest management in Southern Sweden, including a higher share of artificial regeneration and shorter rotations. This allows concluding that, if current forest management practices persist, then an increased “biodiversity gap” may be expected between the two countries. The study concludes with discussing to what degree the identified trends are the direct product of targeted policies versus merely by-products of other factors.

As resources allocated specifically for conservation are limited, there is a need to ensure conservation policy initiatives lead to effective conservation outcomes. In this study, we investigated the potential conservation benefits from alternative spatial allocations of old deciduous stands to a landscape dominated by coniferous production forests owned primarily by non-industrial private forest owners. As a target species, we used the long-tailed tit (Aegithalos caudatus), a species associated with deciduous forests and known to be sensitive to isolation. We used a previously published model based on empirical data on the occurrence of this species, to assess the probability of occurrence of the bird in a 4,000 km2 area in southern Sweden for which we possess detailed spatial GIS data (kNN data) of tree species composition and age. We assessed alternative scenarios where old deciduous forest was allocated with or without respect to distance from existing old deciduous forests. Due to the long-tailed tit’s habitat requirement increasing the amount of old deciduous forests close to existing habitats was the most effective strategy. However, the potential advantages of this strategy may in fact be overturned in favor of the other scenarios if ownership structures and probable uptake rates of policy initiatives are also considered. If a policy initiative is targeted toward owners with properties in close proximity to existing suitable habitat, when compared to if all forest owners are targeted, a higher proportion of owners is needed to participate in order to achieve the same degree of habitat creation for the species. Here, we discuss the potential benefits for effective conservation policy formulation from integrating spatially explicit datasets and detailed ecological knowledge with land-ownership structures and policy uptake scenarios.

We simulated how possible changes in wind and ground-frost climate and state of the forest due to changes in the future climate may affect the probability of exceeding critical wind speeds expected to cause wind damage within one northern and one southern study area in Sweden, respectively. The topography of the study areas was relatively gentle and the forests were dominated by Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). Using estimated changes in the net primary production (NPP) due to climate change and assuming a relative change in the site productivity equal to a relative change in NPP, we simulated possible future states of the forest under gradual adjustment of the site index in response to climate change using the model The Forest Time Machine. Global climate change scenarios based on two emission scenarios and one general circulation model were downscaled to the regional level. The modified WINDA model was used to calculate the sensitivity of the forest to wind and the probability of wind damage for individual forest stands for the periods 2011–2041 and 2071–2100 and for a control period 1961–1990. This was done while taking into account effects on stability of the forest from expected changes in the occurrence of ground frost. Increasing sensitivity of the forest to wind was indicated for both study areas when adhering to recommended management rules of today. Adding also a changed wind climate further increased the probability of wind damage. Calculated probabilities of wind damage were generally higher in the southern study area than in the northern one and were explained by differences in wind climate and the state of the forests, for example with respect to tree species composition. The indicated increase in sensitivity of the forest to wind under the current management regime, and possibly increasing windiness, motivate further analysis of the effects of different management options on the probability of wind damage and what modifications of Swedish forest management are possibly warranted.

We estimated how the possible changes in wind climate and state of the forest due to climate change may affect the probability of exceeding critical wind speeds expected to cause wind damage within a forest management unit located in Southern Sweden. The topography of the management unit was relatively gentle and the forests were dominated by Norway spruce (Picea abies (L.) Karst.). We incorporated a model relating the site index (SI) to the site productivity into the forest projection model FTM. Using estimated changes in the net primary production (NPP) due to climate change and assuming a relative change in NPP equal to a relative change in the site productivity, we simulated possible future states of the forest under gradual adjustment of SI in response to climate change. We estimated changes in NPP by combining the boreal-adapted BIOMASS model with four regional climate change scenarios calculated using the RCAO model for the period 2071–2100 and two control period scenarios for the period 1961–1990. The modified WINDA model was used to calculate the probability of wind damage for individual forest stands in simulated future states of the forest. The climate change scenarios used represent non-extreme projections on a 100-year time scale in terms of global mean warming. A 15–40% increase in NPP was estimated to result from climate change until the period 2071–2100. Increasing sensitivity of the forest to wind was indicated when the management rules of today were applied. A greater proportion of the calculated change in probability of wind damage was due to changes in wind climate than to changes in the sensitivity of the forest to wind. While regional climate scenarios based on the HadAM3H general circulation model (GCM) indicated no change (SRES A2 emission scenario) or a slightly reduced (SRES B2 emission scenario) probability of wind damage, scenarios based on the ECHAM4/OPYC3 GCM indicated increased probability of wind damage. The assessment should, however, be reviewed as the simulation of forest growth under climate change as well as climate change scenarios are refined.

A number of measures have been introduced into Swedish forestry in order to satisfy demands on biodiversity and sustainability. Protection measures include set asides, areas with continuous cover forestry and retention trees on harvesting sites, to name but a few. Most of these practices will have implications for the total wood supply of the Swedish forests. In 1998, the Swedish standard for forest certification according to the Forest Stewardship Council (FSC) was approved. The standard adopts many detailed regulations regarding how forests should be managed. The aim of this study is to assess the likely effect of FSC certification on short- and long-term supply of roundwood in Sweden. A scenario, expressed as the distribution of the forest land base on production forests, areas with restrictions for management and reserves, is input into a simulation model in which forest owners are assumed to be guided by economic criteria when deciding on management. Four scenarios were created based on the data of the Swedish National Forest Inventory. For each scenario the short-term wood supply was assessed. Also, a number of long run simulations with different relative price levels are presented. The results indicate that full adoption of the FSC standard on the entire land base, compared with adherence only to the Forestry Act, could result in a substantial reduction in supply, or, conversely, could induce a price increase in case supplied quantities should be maintained at current levels. This is under the assumption that no compensating mechanisms, exogenous to the model, come into effect. Furthermore, a sustained price increase that would compensate for lost volumes today does not seem to prevail in the long run. In conclusion, the ongoing adaptation of Swedish forestry to the standards of the certification programs could have substantial effects on the timber supply and will probably influence the international competitiveness of the Swedish forest sector. Effects and tendencies like these should form integral parts of future analyses of wood balances and wood supply in a regional perspective.

Even though the growth rates of most tree species in Sweden is expected to increase in the near future as a result of climate change, increased risks of damage by storms and various pests and pathogens, notably root rot and bark beetles, may also occur. Thus, forest management practices such as changes to thinning regimes, reductions in rotation lengths, and switching to other species (native or exotic) may represent adaptive management strategies to increase the resistance and resilience of Swedish forests to climate change. Clearly, thorough analyses examining the effects of anticipated climatic changes on damage levels, and the potentially relieving effects of possible management adaptations are needed before implementing such changes. In this study, damage caused by storms, root rot and bark beetles (single and in various combinations) under selected climate and management scenarios were simulated in Norway spruce (Pice abies L. Karst) stands. The results indicate that reductions in thinning intensity and rotation lengths could improve both volume production and profitability in southern Sweden. In addition, cultivation of rapidly growing species, such as hybrid larch (Larix × marschlinsii Coaz.) and hybrid aspen (Populus tremula L. × P. tremuloides Michx.), could be as profitable as Norway spruce cultivation, or even more profitable. However, slow-growing species, such as Silver birch (Betula pendula Roth), Downy birch (Betula pubescens Ehrh.) and European beech (Fagus sylvatica L.) indicated low economic output in terms of Land Expectation Value.

While sustainable forestry in Europe is characterized by the provision of a multitude of forest ecosystem services, there exists no comprehensive study that scrutinizes their sensitivity to forest management on a pan-European scale, so far. We compile scenario runs from regionally tailored forest growth models and Decision Support Systems (DSS) from 20 case studies throughout Europe and analyze whether the ecosystem service provision depends on management intensity and other co-variables, comprising regional affiliation, social environment, and tree species composition. The simulation runs provide information about the case-specifically most important ecosystem services in terms of appropriate indicators. We found a strong positive correlation between management intensity and wood production, but only weak correlation with protective and socioeconomic forest functions. Interestingly, depending on the forest region, we found that biodiversity can react in both ways, positively and negatively, to increased management intensity. Thus, it may be in tradeoff or in synergy with wood production and forest resource maintenance. The covariables species composition and social environment are of punctual interest only, while the affiliation to a certain region often makes an important difference in terms of an ecosystem service’s treatment sensitivity info:eu-repo/semantics/publishedVersion

Forestry in Sweden has since long been focused on production of conifer timber, but during the last decades the production of other goods and services has become more pronounced. An example of this shift towards multiple-use forestry can be found in the Swedish Forestry Act stipulating that equal weight should be put on preservation of biodiversity and timber production. The demand on multiple-use forestry to reach multiple goals creates a classical production allocation problem. In this study a method for analysing certain spatial production allocation problems in a forestry context is presented. The method is used to evaluate two different strategies for allocation of timber production and production of nature conservation values. One is the strategy of applying one stand management regime in all stands over a forest, given that it produces both timber and nature conservation. The other is the strategy of applying different stand management regimes over the forest. The results show that the strategy of applying different stand management regimes leads to greater production possibilities for timber and nature conservation values compared to the other strategy. However, if the goals of forestry change towards nature conservation, the use of the differentiated strategy could imply a more restricted planning space for nature conservation in the future.

An integrated system of models, WINDA, is presented for calculating the stand-wise probabilities of wind damage, uprooting and breakage of trees within a landscape. The calculations are made point-wise at exposed stand edges. WINDA integrates a modified version of the dose/response model HWIND [Can. J. For. Res. 29 (1999) 647], the airflow model WASP [Wind Atlas Analysis and Application Program (WASP), Riso National Laboratory, Roskilde, Denmark], and a component for calculating the zero-plane displacement and surface roughness and uses a GIS for geographical computations. The likelihood of damage is calculated using extreme value theory. WINDA was able to predict damage that compared well with observed extensive damage within 6.7 km 2 large landscape in southern Sweden. Output from the system of models was most sensitive to modifications in the input variables tree height and diameter at breast height and to the internal parameter critical friction velocity. The mechanistic modelling approach makes WINDA useful for evaluating effects on the probability of wind damage of silvicultural treatments and forestry activities as well as of a changed climate.

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk an...

Spatially explicit data on forest attributes is demanded for various research with landscape perspective. Existing datasets with estimates of continuous forest variables are often used as the basis for producing categorical forest type maps. Normally, this type of maps are used without knowing their accuracy. This paper presents a Bayesian network model for estimating pixel level class membership probabilities of thus derived categorical maps. Class membership probabilities can be used as a post-classification measure of map accuracy and in the process of map classification affecting the assignments of class labels. The method is applied in mapping deciduous dominated forests on the basis of the k-NN Sweden 2005 dataset in a study area in southern Sweden. The results indicate rather low accuracy for deciduous class regardless of the map classification method: 0.48 versus 0.50 in the maps classified without and with the use of the class membership probabilities given equal deciduous area. When probability-based classification is applied, the level of accuracy varies with the assumed map class proportions. Thus, when deciduous class area corresponding to the National Forest Inventory estimate was used, the accuracy of only 0.35 was obtained for the deciduous map class.

European Forest Ecosystem Research Network (EFERN), was set up in 1996 as one result of the Ministerial Conferences on the Protection of European Forests in Strasbourg 1990 and Helsinki 1993 with the aim of promoting ecological research for sustainable forest management. Three plenary meetings were held, each with a specific theme. The results of these meetings have been documented in 10 chapters in a volume with the title ‘Pathways to the wise use of forests in Europe’. The intention was also to give priorities for future forest ecosystem research. In accepting the idea that sustainability includes a multifunctional view of forests, there is a need to find ways of integrating classical forest ecosystem research with biodiversity, water quality and socio-economics. The balancing of the different interests in the forests can be done through planning. From this results also a choice of adequate management methods of the forest resources. The classical stand level in forestry requires now an additional scale — the landscape level. The aim with this paper is to present a concept which attempts to integrate the disciplines involved — ecosystem and landscape ecology and its components. Areas where research efforts are central are also mentioned.

Selection of certain habitat types on landscape, regional or national scales in order to conserve or create desirable ecological structures and/or compositions are often part of nature conservation strategies. In state-owned and industry-owned forests, selection of habitats for nature conservation purposes has been a question of maximizing ecological benefits. In non-industrial private forestry (NIPF), the choice of habitat type affects to what area fraction habitats occur on a forest estate. As this can vary considerably between forest estates, decision makers should consider this variation (the variation in habitat occurrence) when selecting habitat type for habitat protection programs. In this paper, a hypothesis based on the abundance, the average size, and average shape of habitats was developed to explain distribution of habitat occurrence. Monte Carlo simulations and empirical studies of 11,700 ha and 194 forest estates showed that variation in habitat occurrence can be analyzed with information of abundance, size and shape of a specific habitat type.

This paper reviews the approaches to multiple objective landscape planning that have developed in Swedish forestry in the 1990s. The objectives of such planning include primarily timber production and maintenance of biodiversity, but also aspects such as aesthetics and recreation. The variety of approaches and models that have emerged is caused by regional differences in land-use history, forest conditions, recreation pressure, and ownership. We distinguish three approaches: The species approach and the naturalness approach integrate conservation aspects, while the multiple aspects approach integrates several aspects (biological, social, economic, spiritual, etc.) into commercial timber-producing forestry. The species approach is exemplified by the key habitat - corridor model in which key habitats and corridors are preserved to support certain species. The natural landscape model illustrates an example of the naturalness approach, as it integrates natural forest features from a fire-disturbed landscape and gives examples of management implications at the landscape as well as at the stand level. The multiple aspects approach combines several objectives and defines important structures rather loosely. This approach was developed in areas where private nonindustrial forestry dominates. Nontimber and nonconservation aspects therefore become relevant to forest management. The supportive feature model exemplifies an application of that approach.

Technical aspects of forest management planning as decision-support have been addressed in numerous scientific studies. However, forest management plans (FMPs) also play a significant, but largely neglected, role as forest policy instruments. We have examined the policy context and planning practices in two contrasting case countries, revealing striking differences in policy instrumentation. In Sweden, FMPs mainly serve for informational steering, with under-utilised potential for providing individualised advice. In Lithuania, the plans are primarily regulatory, serving for effective control but with several deficiencies, notably excessive costs and institutionalised corruption. The study demonstrates that policy analyses can be fruitfully grounded in the empirics of planning practices.

Regulations defining the maximum opening size in the sub‐alpine region of Sweden, introduce new planning issues. The combinatorial problems that arise in harvest planning become very complex, but can be solved by different methods. In a case study, three different ways to find a solution were examined: a random search algorithm, a simulated annealing algorithm and the prebiased random search method found in the SNAP II program. Two different alternatives were studied, one with no road in the area and one with a road constructed. All three methods were found to give feasible solutions. The simulated annealing produced the best solutions, in terms of present net value, while the SNAP II program was the fastest. The SNAP II did not give as good solutions as the others in the case with a road, probably due to the lack of a distinct gradient in the structure.

Several hazards for forest production can be identified, such as damage caused by wind, frost, insects or pathogens. Modelling efforts of ours have been concentrated upon the risks of damages by wind and frost, landscape level models for which will be presented below. A landscape is defined as an area of anywhere from a few km2 to several tens of km2.

The primary focus of the SUFOR research programme was the Asa Royal Forest Park, 33 km2 in size, in which the Asa Forest Research Park 12 km2 in size, is included. A field station of the Swedish Agricultural University is located in the park, which was expropriated from its German owner in 1945 and become a Royal domain. The area is host to a number of research projects and conditions for synergistic cooperation is good. Technicians from the station assisted in sampling and data collection. Various parameters of the area are shown in Tab. 14.2. The park borders to Lake Asa, the majority of the area being found on the western side of the lake. A map of the area is shown in Fig. 13.1. The park is located 40 km north of the city of Vaxjo in the province of Smaland. Forestry in the area is traditional conifer forestry, representing the point of departure for any future changes. In the past, the original forest cover in Asa was a mixed deciduous forest dominated by lime (Tilia) and alder (Alnus), and also containing European beech (Fagus sylvatica), Scots pine (Pinus sylvestris), oak (Quercus robur) and birch (Betula). Farming on the shores of the lake started around 1200 AD and Norway spruce entered the landscape on a small scale around 1600. Mixed deciduous vegetation dominated until clearance of the land by farmers from about 1700 onwards. After 1840, Norway spruce increased markedly through colonization and through planting on land that had been abandoned after large numbers of emigrants went to America. Small crofts and farms were reforested, a process that in the province of Smaland continued as a result of urbanization from about 1930 on until the present day. From now on conifers, and Norway spruce in particular, are dominant.

A method for forecasting the log‐class distribution resulting from harvesting forest stands is investigated. The diameter distribution of a stand is approximated by a two‐parameter Weibull density function, the parameters of which are recovered from stand level characteristics. Theoretical bucking is performed for actual and simulated distributions and the resulting log yields are compared. An application to 40 stands indicates that an accurate prognosis can be expected, given a good approximation of the diameter distribution. For cases with multimodal diameter distributions or many small trees, the prognosis is unreliable.