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Varieties of forests and varieties of functions


A forest produces wood, filters pollutants from the air, protects drinking water, stores carbon and contributes to bio - diversity. It can take the form of a lush green mixed forest with beech trees, a landscape dominated by chestnut glades, or a species-rich mountain forest. Each is a complex ecosystem containing thousands of interconnected plant, animal and fungus species. In such natural areas we study the effects of soil, water, air and climate on the growth and development of forest ecosystems. WSL researchers cooperate with researchers from other fields, and with officials working for the federal government and the cantons.

Effects of natural hazards and climate change

We are particularly interested in the effects of storms, fires and avalanches on forest regeneration and biodiversity and in how climate change is affecting forests in general. In Canton Valais we have found that pine trees (Pinus sylvestris) tend to die in exceptionally warm and dry years, whereas pubescent oak trees (Quercus pubescens) spread. In abandoned forests in Canton Ticino, evergreen, thermophile woody species and palm trees are moving in and some invasive species have begun to displace the original vegetation. WSL researchers analyze the effects of climate and forest management on forest variables ranging from trees to material cycles. These cycles are influenced by the deposition of nutrients and pollutants in forests and the decay processes of leaves, needles and dead wood. Findings from this research provide a basis for developing strategies for sustainable forest use, nature conservation, practical applications and further education.

Using wood, maintaining forests, protecting soils

Foresters want to know how to make optimal use of forests, in particular of their timber. The aim is to ensure this is economically feasible and is not interfering with the other forest functions, such as providing recreational areas for people, habitats for plants and animals, and protection against natural hazards, as well as safeguarding drinking water. We study the state and the development of Swiss forests and the kinds of human intervention that can influence them one way or another. On experimental plots we have therefore been recording tree growth and yield, in some cases for over 100 years. We also use state-of-the-art computer models and conduct complex surveys, such as the National Forest Inventory. The resulting insights can be fed into practice via software or Internet platforms, information leaflets or courses. We provide practical information about topics such as soil protection during the timber harvest, economic optimization of the chain of production for wood, potential use of wood for energy and the recreational value of a forest. 

Exploring the roots

Below-ground processes are today receiving much more attention in forest research. At WSL, we study the interactions between roots, fungi, bacteria and forest soil. The carbon and nitrogen cycles are particularly important as they both greatly depend on temperature and precipitation. Thus research at the WSL site, Stillberg, near Davos, for which records go back 50 years, has yielded very valuable information on climate change. This site is right on the timberline, where young trees react very sensitively to changes in climate. Old trees are also a valuable source of data for climate studies because they store infor mation on environmental conditions in their wood for a long time. WSL has the second largest tree-ring research lab worldwide, which regularly produces new findings that contribute to international climate research.