Solving the stand management problem under biodiversity-related considerations

Abstract

A new solution method to solve the even-aged stand management problem that results when biodiversity-related demands are taken into account is presented. The model was based on single-tree growth functions, the meta-heuristic optimisation technique: tabu search and greedy heuristics. The timing of thinnings and final harvest was recognised, and fixed entry cost included. Biodiversity considerations were expressed in terms of stand attribute targets for coarse woody debris, tree-size diversity and tree retention. The performance of the model was demonstrated with a case example, where the model was applied to simulated, mixed stands of Norway spruce and birch. The model was able to solve huge problems in a short time. Cost curves for the non-timber outputs are presented. The biodiversity considerations typically affected the time for final harvest, number of thinnings and thinning form.