There are few ecosystems in Switzerland which have been as thoroughly studied as the country’s forests. This is due in part to the National Forest Inventory conducted by WSL. It provides an important basis for decisions affecting Swiss forest and environmental policy.

Almost one third of the surface area of Switzerland is wooded. A growing number of interests are colliding on this land. The forests provide a habitat for animals and plants and a recreation area for people, they supply timber and protect against natural hazards, particularly in mountainous regions. Politicians, researchers, ecologists, forest managers and the timber industry all need up-to-date and comprehensive data if they are to use and protect the forests on a sustainable basis. This information is supplied by the National Forest Inventory (NFI), managed jointly by WSL, a research institute in the ETH Domain, and the Forest Division of the Federal Office for the Environment (FOEN). The NFI and other surveys together form a national forest information system. 

Systematic sampling throughout Switzerland

The NFI records the state of and changes in Switzerland’s forests. Systematic sampling enables scientists at WSL working with local forestry service providers to record data on trees, growing stocks and trial areas. The published results include information on forest area, the number of trees, growing stocks, increments, use and biodiversity. WSL is responsible for planning, surveying, analysis and scientific interpretation, while FOEN handles the political aspects. The first NFI took place from 1983 to 1985, the second survey followed from 1993 to 1995, and the third inventory was carried out from 2004 to 2006. The continuous survey for the fourth NFI started in 2009 and will run until 2017.