Ola Sallnäs

Harvest scheduling under adjacency constraints — a case study from the Swedish sub‐alpine region

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.

Risk perception among non-industrial private forest owners

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 respondents 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 and a high level of ignorance in relation to whether risk-reducing measures were taken.

Forest ecosystem research - priorities for Europe.

Abstract 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.

Spatial patterns of habitat protection in areas with non-industrial private forestry—hypotheses and implications

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.

A model for predicting log yield from stand characteristics

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.

An integrated modelling framework for the forest-based bioeconomy

This paper describes the conceptual design of a regional modelling framework to assess scenarios for the forest-based bioeconomy. The framework consists of a core set of tools: a partial equilibrium model for the forest sector, a forestry dynamics model for forest growth and harvest and a wood resources balance sheet. The framework can be expanded to include an energy model, a land use model and a forest owner decision model. This partially integrated, multi-disciplinary modelling framework is described, with particular emphasis on the structure of the variables to be exchanged between the framework tools. The data exchange is subject to a series of integrity checks to ensure that the model is computing the correct information in the correct format and order of elements.

Forest Resource Projection Tools at the European Level

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.

Models of the risk of windthrow and frost

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.