Assessment of the Predisposition of Spruce-Abundant Forests to Various Disturbances : Spruce Monocultures in Central Europe - Problems and Prospects

2000

S. 113-117

3 Tab., 3 Lit.

Unselbständiges Werk

200072681

With the increasing limitation of personal and financial resources in forest management, the role of preventive forest protection becomes more and more important. Aiming at the improvement or the warranty of special forest functions and the reduction of production risks, a wide range of tools reaching from mechanistic to statistical models can be used. Referring to the goal of the present study, a system with widest possible applicability (primarily for spruce-abundant forests in Austria) has been established, which belongs to the category of mechanistic models. This model is to derive the predispostion of a given stand or a larger forest unit for various biotic and abiotic destructive agents. It contains a set of indicators - found by an intensive literature analysis - which are presumed to be essential for the prediction of predisposing site and stand situations. The final system will combine singular predisposition-models of special damaging agents such as storm, snow, hoarfrost and air pollutants as well as phytophageous insects or important fungi. The prediction-system for each impairing factor consists of an award-penalty-point system with facultative knock-out-criteria, where a list of relevant impacts is made up. These lists contain indicators such as altitude, slope or soil type for the site-related assessment as well as tree species, stand density or developmental phase, for example, for stand-related assessment. The indicators have been split into classes in order to establish a scale, where a specific score is assigned to every scale level corresponding to its contribution to the overall-predisposition. In consideration of the predisposition-increasing or -decreasing effect of those very scale levels, positive or negative signs have been put to each score. Applying the system to a given site or stand, the specific scores of each correct scale level of the indicator list are summed up to an actual total amount. The result is related to a pessimal total amount and this percentage can be interpreted as a relative predisposition.