The study proposes a technique which enables the computation of user-defined indices for species diversity. These indices are derived from characteristics, called diversity indicators, of inventory plots, stand compartments, and the whole forest holding. The study discusses the modifications required to be made to typical forest planning systems due to this kind of biodiversity computation. A case study illustrating the use of the indices and a modified forest planning system is provided. In the case study, forest-level species diversity index was computed from the volume of dead wood, volume of broadleaved trees, area of old forest, and between-stand variety.
At the stand level, the area of old forest was replaced by stand age, and variety was described by within-stand variety. All but one of the indicators were further partitioned into two to four sub-indicators. For example, the volume of broadleaved trees was divided into volumes of birch, aspen, willow, and other tree species. The partial contribution of an indicator to the diversity index was obtained from a sub-priority function, determined separately for each indicator. The diversity index was obtained when the partial contributions were multiplied by the weights of the corresponding indicators and then were summed. The production frontiers computed for the harvested volume and diversity indices were concave, especially for the forest-level diversity index, indicating that diversity can be maintained at satisfactory level with medium harvest levels.
The paper deals with the methodological problems concerning policy planning and evaluation in small woodlands. A methodological approach to effectiveness of forest policy measures calls, according to the author, for using a frame of reference formed by general economic theory and models of forest owners’ behaviour. Thus, it is important for the selection of forest policy means, and for evaluating the likely effects of a policy, to know the behaviour of the decision makers being influenced. The use of models of forest owners’ behaviour in planning forest policy is motivated by the fact that measures must often affect the woodlot through the owners’ decision making.
The PDF includes a summary in English.
The study explores the mental and environmental factors affecting the normative and strategic decision-making of forest owners. Four value orientations: preference for subsistence economy, attachment to land, resistance to change and traditionalism are defined by the aid of factor analysis, as well as six ecological types of farming: (1) problem farming, (2) extensive part-time farming, (3) prosperous field farming, (4) labour-intensive family farming, (5) part-time farming, and (6) commercial farming. The decisions analysed on the basis of these theoretical constructs concern management, cooperation and the promotion of private forestry. Some philosophical problems connected with the use of mental variables are also discussed.
The PDF includes a summary in Finnish.