Evighetsträd
FSC (Forest Stewardship Council) is the major form of certification system in Swedish forestry today and its more than 11 million hectares are covering almost half of the total productive forest area in the country. Its regulations prescribe that at least 10 wind firm trees should be left behind after every clear cutting operation.
This study have taken place on 30 recently clearcut objects in Bergslagen, Sweden, were an inventory of the standing stock have been made. The research shows that, with 90 % security, the retained trees together contain 9-13 m3sk per hectare. Pine is the dominant tree and it covers more than half the numbers of retained trees and its volume cover 65 % of the retained trees total volume. Spruce is on second place with 30 % of the retained trees, but only 21 % of the standing stock. Birch is on third place with 15 % of the trees and 11 % of the retained trees total volume. 2/3 of the retained trees are between 20-25 cm dbh and only 20 % of the stems are having a diameter at breast height larger than 30 cm.
Fire has historically been the most common disturbance regime on a landscape level in the boreal parts of Sweden. To prevent the loss of biological diversity in the forest the silvicultural system must imitate the previus disturbance regime. By leaving 10 trees per hectare after every clearcutting operation the dominating silvicultural system in Sweden is imitating the fire disturbance regime well and 26 % of the red-listed species will have better chances to survive in the forest.