Adaptation of forest ecosystems, forests and forestry to climate change. FINADAPT Working Paper 4

In this study, an ecosystem model (Sima), capable of predicting ecosystem level functioning of boreal forests, was used together with a permanent sample plot data of the Finnish national forest inventory (measured in 1995) and different climate scenarios to analyze, how increase in temperature, precipitation and atmospheric carbon dioxide concentration may effect forest growth and dynamics in Finnish conditions. The simulations showed that the forest ecosystems are most impacted in the most northern and in the most southern parts of the country (2000-2099). In the north, the productivity of the forest ecosystems may increase substantially. In this respect, the northern forests may provide many opportunities for forestry and timber production. In southern Finland, the climate change may also increase in general the productivity of the forest ecosystems. However, it may also create environment suboptimal for Norway spruce, the growth of which may reduce throughout southern and central parts of the country. The dominance of Scots pine may increase on less fertile sites currently occupied by Norway spruce. Birch may compete with Scots pine even in these sites, and the dominance of birch may increase. The management of Finnish forests should therefore be adapted to meet the higher productivity and changing tree species composition in the future. These expected changes in growth and trees species composition may have locally negative effect on the total growth in Southern Finland, but at the nation-wide the total growth may increase up to 44 %, with an increase up to 82 % in the sustainable potential total cutting drain over the country