Biodiversity, carbon storage and dynamics of old northern forests

Forests play a key role in the global climate system. The Nordic countries have extensive forests with large and growing tree biomass that captures substantial amounts of the greenhouse gas carbon dioxide. Nordic forests are also important for biodiversity, with complex ecosystems providing habitats for about half of all known native species and threatened species in Finland, Norway, and Sweden. Forests also supply the basis for the economically important forest sector. In this report we review current knowledge on the role of old forests in the carbon cycle, their natural dynamics and importance for biodiversity. Based on evidence in the literature, it is clear that old forests continue to accumulate carbon for a long time, well past the normal logging age. The carbon uptake of old forests represents an important co-benefit for the well-documented value of old forests for biodiversity.