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About a third of Switzerland is covered by forest, which is one of the hallmarks of our landscape and enhances our quality of life. We are studying this complex ecosystem to find appropriate ways in which people can use and protect the forest.


Forests offer protection against natural hazards such as rockfalls and avalanches, filter our drinking water and prevent soil erosion. They provide wood, store carbon, and serve as recreational spaces for people, habitats for flora and fauna, and havens of biodiversity.

Impact of climate change and natural events

Threats to the above-mentioned forest functions are mounting as a result of the worldwide upheavals in the climate system and in society: what impact do climate change, loss of biodiversity, invasive species and productivity levels in timber production have on our forests? What happens with nutrient cycles, carbon storage, the resistance of the forests to pests, and the services which are of consequence to mankind?

Timber utilisation, forest preservation and soil protection

We are exploring these issues as part of our research. Our focus is on the sustainable exploitation of forest resources, which maintains and supports the functions and adaptability of the forest. Several long-term forest monitoring projects and experimental plots, some of which we have operated for more than 100 years, provide data series documenting the condition and usage of Swiss forests. They also facilitate an understanding of how soil, water, air and climate, pollutants and disturbances, such as storms and forest fires, interact with the forest ecosystem.

A look ahead

We want to take a look at the possible future of the forests, and this requires broad-based research including long-term observations, information from annual tree-ring data which reach far into the past, laboratory and field experiments, computer modelling, and in-depth knowledge of management practices. We combine all these approaches under one roof, using state-of-the-art environmental research techniques, such as isotope analysis, for which we operate a separate isotope laboratory.

As one of the world's leading forest research institutes, we participate in numerous European and international research networks such as the Long-Term Ecosystem Research (LTER) Network in Europe. We coordinate a network of leading Swiss forest researchers from various disciplines as part of our strategic initiative SwissForestLab, so that these researchers can join forces in addressing the most important research questions.

And last but not least, as a federal institute, we also perform the task of imparting our knowledge to forestry practitioners and nature conservationists in the form of recommendations, leaflets and continuing education.



Forest protection Switzerland

The specialist unit for forest protection issues at the WSL.

Forests and climate change

Climate change will drastically alter the Swiss forests, with consequences for humans. WSL conducts research into the relevant processes.

Forest development and monitoring

Long-term environmental observation detects gradual changes, including climate effects and the input of pollutants.

Forest management and forest functions

How does forest develop, and how can we use it without affecting its essential processes and services?

Soil and cycles

We monitor and measure how environmental influences alter the living conditions in the forest soil and study the processes that occur in root areas.

Diseases, pests and disturbances

Damage caused by insects, pathogenic agents, storms and forest fires all devastate forests. We investigate how the forest reacts to these phenomena.

Tree-ring research

Trees react to their environment. At WSL, tree-ring scientists date and analyze these natural archives.



"": melting ice can release viruses and bacteria that are potentially harmful to humans. With Beat Frey (WSL).

The forest canopy mitigates peak summer temperatures for the understorey. When that shade disappears, the organisms living there suffer.

A real visual treat: Info Flora’s species portraits now include over 1,000 stem cross-sections and descriptions prepared by WSL collaborators.

Burnt beech forests provide less protection against natural hazards than intact woods. A new WSL Fact Sheet describes the fire and vegetation…




Durch den Klimawandel wird es wärmer und extreme Trockenheitsperioden werden häufiger. Deshalb steigt das Waldbrandrisiko. Mit einem umfassenden Wissen zur Feuerökologie kann besser abgeschätzt werden, ob Schutzleistungen erhalten bleiben oder waldbauliche Massnahmen zu treffen sind.

Merkblatt für die Praxis 65

Salehi, M.; Walthert, L.; Zimmermann, S.; Waldner, P.; Schmitt, M.; Schleppi, P.; Liechti, K.; Ahmadi, M.; Zahedi Amiri, G.; Brunner, I.; Thimonier, A., 2020: Leaf morphological traits and leaf nutrient concentrations of European beech across a water availability gradient in Switzerland. Frontiers in Forests and Global Change, 3: 19 (18 pp.). doi: 10.3389/ffgc.2020.00019

Reinig, F.; Cherubini, P.; Engels, S.; Esper, J.; Guidobaldi, G.; Jöris, O.; Lane, C.; Nievergelt, D.; Oppenheimer, C.; Park, C.; Pfanz, H.; Riede, F.; Schmincke, H.; Street, M.; Wacker, L.; Büntgen, U., 2020: Towards a dendrochronologically refined date of the Laacher See eruption around 13,000 years ago. Quaternary Science Reviews, 229: 106128 (6 pp.). doi: 10.1016/j.quascirev.2019.106128

Pushkareva, E.; Eckhardt, K.; Hotter, V.; Frossard, A.; Leinweber, P.; Frey, B.; Karsten, U., 2020: Chemical composition of soil organic matter and potential enzyme activity in the topsoil along a moisture gradient in the High Arctic (Svalbard). Geoderma, 368: 114304 (9 pp.). doi: 10.1016/j.geoderma.2020.114304

Nussbaumer, A.; Meusburger, K.; Schmitt, M.; Waldner, P.; Gehrig, R.; Haeni, M.; Rigling, A.; Brunner, I.; Thimonier, A., 2020: Extreme summer heat and drought lead to early fruit abortion in European beech. Scientific Reports, 10: 5334 (11 pp.). doi: 10.1038/s41598-020-62073-0

Götz, L.; Psomas, A.; Bugmann, H., 2020: Früherkennung von Buchdruckerbefall dank Fernerkundung: Was ist schon möglich?. Schweizerische Zeitschrift für Forstwesen, 171, 1: 36-43.