In mountain areas rockfalls are frequent events. Their unpredictability, in terms of frequency and magnitude, determines the potential hazard for humans, settlements, and infrastructure in these areas. Different artificial protection methods against rockfall exist, such as barriers and restraining nets. However, a natural form of protection is provided by the forest growing on mountain slopes. The di±culty when regarding the forest stand as a protection barrier against rockfall is to assess and predict its protective effect. The aim of this study is to develop a numerical model that can be used to estimate the energy absorption capacity E_cap of a single tree during a rockfall. These values can thereafter be implemented in a coupled rockfall singletree model, which can then be used to study the protective effect of the forest. [...]