Silviculture has been one of the cornerstones of Swiss forest science for more than a century, with Swiss scientists contributing several pivotal silvicultural ideas and approaches that are still used today (e.g. forests management according to the selection system). A strong base in silvicultural research is critical because more than 70% of Switzerland's forests are managed, and the sustainable management of these forests requires a solid scientific base of evidence.
Despite the relatively small size of the country, a wide range of silvicultural regimes are applied in Swiss forests. This is due to the diversity of forest types and management objectives, as illustrated below.
Figure 1. Silviculture deals with a wide range of forest types, species, stand structures and climatic or edaphic factors.
The silvicultural research at WSL includes traditional growth and yield analyses using several plot networks; one of which (Experimental Forest Management project) includes plots that have been monitored for >100 years, making them among the oldest in the world. Other networks focus on providing excellent spatial coverage of Swiss forests (National Forest Inventory, NFI), or provide reference plots in unmanaged forests (natural forest reserves in Switzerland). A fourth set of plots are intensively measured to examine a range of ecosystem functions, including nutrient, water and carbon cycles (Long-term Forest Ecosystem Research Programme LWF).
The processes studied using these datasets include tree growth, mortality and regeneration under the influence of silvicultural interventions and environmental factors. By establishing and maintaining these plot networks, we also provide substantial support to projects focusing on forest functioning. Such projects require growth and yield data to complement their measurements of tree physiology and various pools and fluxes, or to develop and test forest growth models. There is often strong international collaboration designed to combine and strengthen data sets, to test the generality and robustness of results and to maximise the quality of the research.
Critically, there is also a strong and continuous link with Swiss foresters, who manage the majority of the forests where the plots are located. The foresters also provide guidance on which questions they consider important topics for new projects. Other examples of our silvicultural outreach are the Swiss Forestry Journal, which provides an excellent platform for presenting the results of some of the more applied research projects, and the «Verbund Waldbau», which is a group of silvicultural scientists and teachers who meet to develop silvicultural research and teaching within Switzerland.