The Finnish classification of forestry land is based on the annual forest increment. On productive forest land the annual increment per hectare is over one cubic metre. On poorly productive forest land the increment is 0.1–1 cubic metre, and on unproductive forest land less than 0.1 cubic metre per hectare per year. In addition to this, forestry land is taken to include protected forests and also logging roads, intermediate timber storage areas by the roadside and other similar areas.
Source: E-yearbook of food and natural resource statistics for 2015. Natural Resources Institute Finland. Updated 7.6.2019.