The forest protects the population and infrastructure from the effects of natural hazards, such as avalanches, rock falls, landslides and floods. It also hinders harmful processes or helps reduce their impact. At the national level, the NFI measures the condition and development of Swiss protection forests.
The goal is to assess the effectiveness of the ability of forests to protect by using the NFI's data according to the specifications set forth in the concept "Sustainability and Success Monitoring in Protection Forests". The criteria vary depending on site type and hazard processes. They encompass tree species composition, forest structure, information on gaps, and the presence of dead wood and regeneration. Remote sensing and terrestrial forest inventory methods are also used to survey forest characteristics. New methods – e.g. terrestrial laser scanning – are continually being tested in order to optimize the quality and spatial representativeness of the NFI's data.