The habitats of special importance for biological diversity are defined in the Forest Act. These habitats are usually in their virgin state or slightly modified and they are small in size. Forest management practices have to be carried out in such a way that the special features of these habitats are maintained. The majority of the threatened forest species live in heathland forests and they depend on decaying wood of different degrees. Efforts are made to increase the amount of decaying wood in commercial forests by leaving green tree retention and decaying wood on the stand after harvesting. A special feature of natural boreal forest is occurrence of fire and the organisms living in burned wood. Use of prescribed burning should be increased to revive these species in commercial forest.
The management of forest nature has improved considerably during the past decade. The measures taken are monitored annually both on state, company and private forests. Monitoring provides information of the level of nature management and knowledge on the preservation of habitats of special importance in harvesting. Monitoring gives detailed information on quality and amount of retention trees that have been left on harvesting sites. It also tells what kind of water protection measures and soil preparation methods have been taken, and how is the landscape management aspects been taken into account. The monitoring also provides data on costs of nature management.