Prädispositionen, Schadauslöser, Synergismen

1998

S. 207-236, 361-362

Unselbständiges Werk

200065965

The manifestation of forest diseases or pest infestations represents a final result of the concurrence of exogenous stresses and tree specific states of predisposition and reflects the resilience of an ecosystem. Impact chains of straining factors such as disturbances of the water budget or the nutrient and carbonmetabolism of trees determine the attacking success of secondary as well as primary pests. Highly destabilised forest ecosystems are assessed to be poorly tolerant of additional loads. The condition of forests in the Glein area can be classified as highly predisposed to disease and pest infestation, which is a function of the multi-layered complex and other triggering factors. While all visible weakened trees or stands obviously do not hold high levels of attraction, trees of latent weakness are an important indicator of possible danger and therefore should be monitored as part of preventative forest protection. The localisation of susceptible sites and stands represents an essential aspect of forest management. Recently established models for the identification of predisposing conditions of spruce abundant forests are considered preliminary attempts in the development of supporting tools for forest management decision processes. The assessment of danger potentials is based on important indicators, which are combined in the form of an award-penalty-point-system for both site and stand related predisposition assignment. By means of such predisposition keys, the susceptibility of spruce-abundant forests to snow and storm damage, the crucial factors in the formation of bark beetle outbreaks can be derived. Considering the data sources for determining the predisposition in the enterprise Glein, primary intervention potentials could be identified using certain stand properties, while the use of site-related data only revealed low levels of predisposition and consequently low damage prevention potentials.