Balancing tradition and technology to sustain rockfall-protection forests in the Alps

It is still uncertain what a mountain forest should look like to provide optimal protection against rockfall. Knowledge is limited due to the slow reaction of mountain forests to the rapid environ-mental and socio-economic changes that have occurred in the Alps over the past 100 years. Fortunately, research has progressed and an enormous amount of experiential knowledge has been gained, providing a basis for finding a balance between maintaining traditional practices and implementing new technology. This paper identifies an approach that could be used as a rough framework for managing and sustaining forests with a protective function in the Alps. Three main points are discussed: 1) evaluating traditional ‘good practices ’ and mistakes, 2) evaluating new technologies, especially those in the field of rockfall-protection forests, and 3) merging the best of the two worlds. The evaluation of traditional ways of managing protection forests shows that the 'do nothing approach ' and earlier trends in spatial planning should be avoided. In the past, people were more inclined to believe that risks were always present in mountain areas. Aware of the protective functions of forests, they did not touch forests in areas where natural hazards posed risks to settlements. Protection forests were therefore not subject to harvesting. In addition, construction did not take place in areas where natural hazards posed high risks. A review of the technologies developed during recent decades shows that we can now assess quantitatively how well different mountain forests perform in providing protection against rockfall. We show how new research tools can help in assessing the required silvicultural actions to optimise the pro-tective function of forests