Predicting the selection of elite trees in mixed-species stands - a rule-based algorithm for silvicultural decision support systems

Scenario simulation of silvicultural alternatives in stand management and a multi-objective evaluation of the generated scenarios support the decision process in strategic management planning. Management alternatives can be generated by applying different thinning concepts, thinning intervals, changing the thinning targets within the expert system-based thinning model ThiCon, or selecting different elite trees, if applicable, using the silvicultural decision support system BWINPro. The automated elite tree selection algorithm is introduced as an instrument to generate scenarios (Fig. 1). The decision to identify a tree as an elite tree in the model is based on the single-tree attributes crown vitality, stem quality, and distance to the nearest elite tree while respecting user-defined minimum requirements for elite trees. The evaluation of the selection algorithm shows that a realistic elite tree identification is possible even in diverse mixed-species stands (Tab. I to 6). Differences between actual and simulated elite tree selections are in the range of possibly occuring differences between several elite tree selections by foresters in a stand (Tab. 6). The two simulated scenarios demonstrate how the decision support system BWINPro can help to solve multiresource forest management planning problems (Tab. 7 and Fig. 2).