Vulnerability assessment to wind damage in a protective forest stand in the Alps.

The risk of wind damage to European forests is expected to increase due to the changed climate. Therefore, research efforts in forestry have been focussing on the development of analytical and modelling tools to improve the prediction of forests' susceptibility to wind damage, and ultimately to support forest management decisions in increasing wind resistance in forest stands. Recent catastrophic wind damage to European forests has shown that wind damage risk applies also to montane forests. Some of them are of particular importance for the various ecosystem services they provide, including protection from gravitational hazards and defence against soil erosion. At present, the available forest wind risk models have been tested and used mainly on production or planted forests in different countries, but never in the complexity of mountainous terrains. The aim of this study is to introduce a methodology for the validation of a new parametrization of ForestGALES wind risk model for the alpine environment. The parameterisation was developed through field tests (e.g., pulling tests on trees) and validated based on the observed wind damage caused by the storm Vaia, which occurred in northern Italy in October 2018, and the pre-disturbance forest characteristics. The use of this parameterisation can allow the construction of wind vulnerability maps starting from LiDAR data. Mapping vulnerability to natural disturbances, in this case, wind, is an essential tool for forest planning and management. The frequency of natural disturbances is expected to increase, as is their severity and forest management needs to target interventions to obtain more resistant and resilient forest stands. Management should aim to apply strategies to prevent future damage in a way that ensures continued protective effectiveness, guaranteeing the preservation of local communities and infrastructures.