Assessing the growth of a forest

For over a hundred years, the National Forest Inventories (NFI) have been used to monitor the state of Finnish forests. As a result, Finland’s forest resources are very well known, and we have detailed data on the development of the tree stock. The NFI data is based on a statistical sample and measurements of more than one hundred variables in test areas all over Finland. During the history of the NFI system, the number of trees and the carbon stock sequestered in the trees have increased by around 70 per cent, and the annual tree growth has more than doubled. Compared to the situation one hundred years ago, the volume of old-growth forests has increased in Southern Finland and decreased in Northern Finland. Severe forest damage occurs only on two per cent of forest land. The development of structural features that are essential for biodiversity, including decaying wood, deciduous trees, sturdy aspens, and retention trees at felling sites, has been positive ever since ecological management was incorporated into forestry in the 1990s.