Statistics Norway Changing the course of rivers and drainage of wetlands are examples of changes in the landscape influencing our conception of its value. The wetlands, which include marshes, river deltas, tarns, bogs, swamps and areas of shallow water along the coast, are the most threatened ecosystems existing in Norway today. They are characterized by high biological production and a large diversity of species. In the northern part of Norway it is possible to find large areas of marsh that are still unexploited. These areas belong to Europe's least influenced ecosystems.
Modern forestry is in many areas a sort of semicultivation of nature.
Ditching and drainage of marshes and other wetlands for forestry and agricultural purposes, and for extraction of peat, has been the greatest pressure on this type of ecosystems. Ditching of forest land in Norway peaked in the 1950s and 60s. Since 1989 the extent of ditching of forest land has decreased after withdraval of government subsidies.