Biodiversity and Sustainable Forestry in Changing Landscapes-Principles and Southern Sweden as an Example

We discuss die human impact on the forests of northwestern Europe, especially changes in disturbance regimes and changes in the density of important features for biodiversity preservation. In southern Sweden, human impacts have decreased densities of old (>150 years) living trees and large (DBH > 40 cm) dead trees to less than 1% of their original densities. In the same fashion, forest fires have decreased enormously in extent during the last 300 years, except in southwestern Sweden where the original fire frequency was presumably lower. These changes have had a tremendous impact on forest biodiversity. The number of extinctions in Sweden increases rapidly from the north to the south both for forest living species and other species. The number of threatened species shows a similar pattern and it is probable that many of these species belong to the extinction debt, especially those species that are dependent on sun-exposed old living and dead deciduous trees. Rapid restoration measures, such as increasing the number of old sun exposed oaks and large dead deciduous trees in the vicinity of existing hot-spots, may prevent some impending extinctions. Fire is important to use when managing forests for preserving biodiversity, especially in areas where fires more recently have been suppressed and where a relict fire-adapted fauna is Still present.