Wald und Klimawandel in der inneralpinen Trockenregion Visp

Over the past decades, observed increases in temperature have been particularly pronounced in mountain regions. If this trend should continue in the 21st Century, frequency and intensity of droughts will increase, and will pose major challenges for forest management. Under current conditions drought-related tree mortality is already an important factor of forest ecosystems in dry inner-Alpine valleys. Here we assess the sensitivity of forest ecosystems to climate change and evaluate alternative forest management strategies in the Visp region. We integrate data from forest monitoring plots, field experiments and dynamic forests models to evaluate how the forest ecosystem services timber production, protection against natural hazards, carbon storage and biodiver-sity will be impacted. Our results suggest that at dry low elevation sites the drought tolerance of native tree species will be exceeded so that in the longer term a transition to more drought-adapted species should be considered. At medium elevations, drought and insect disturbances as by bark beetles are projected to be important for forest development, while at high elevations forests are projected to expand and grow better. All of the ecosystem services that we considered are projected to be impacted by changing forest conditions, with the specific impacts often being elevation-dependent. In the medium term, forest management that aims to increase the resilience of forests to drought can help maintain forest ecosystem services temporarily. However, our results suggest that relatively rigid management interventions are required to achieve significant effects. By using a combination of environmental monitoring, field experiments and modeling, we are able to gain insight into how forest ecosystem, and the services they provide, will respond to future changes.