Extinction debt and species credit in boreal forests: Modelling the consequences of different approaches to biodiversity conservation

Abstract

The extinction debt of boreal forest species is estimated to be of the order of 1,000 species in Finland. Using a spatially explicit metapopulation model, this paper examines the likely consequences for the survival of species of different scenarios of forest management and conservation. The results point to the conclusion that it generally pays to concentrate the efforts of improving forest quality at certain areas rather than to spread the same total effort evenly and therefore thinly throughout the entire forest landscape. The practical conclusion is that in southern Finland an extensive restoration program of managed forests to natural-like successional forests is needed to avert the imminent wave of extinctions of specialist forest species. The greatest positive effect is obtained if forests located close to the existing remnants of biologically diverse forests are restored, which would facilitate the migration of target species to the restored forests.