The spacing of mature forest habitat in relation to species-specific scales in managed boreal forests in NE Finland

Modern forestry alters the structure of boreal forest landscapes, and this affects several forest species with different habitat requirements. Quantitative analyses of the structure of real landscapes are scarce, although this information will be needed in landscape-level planning and management applications. We investigated the occurrence and configuration of mature forest (> 80-100 year) in relation to five different extents (ranging from 20 to 7 854 ha) of circular landscapes around random points in managed forest environment in NE Finland. The habitat type was coarsely chosen according to requirements of certain resident birds and mammals. We present an approach where species-specific home-range scales are related to the observed environmental heterogeneity pattern for assessing the potential of actual landscapes to maintain these species. As a result we found that there is a minority of landscapes where total area of mature forest was comparable to species' home ranges. Irrespective of the scale examined, the average proportion of habitat in a landscape was approximately 15%. Besides that the mature forest was physically fragmented already on a scale relevant to individual animals, the variation in habitat proportion between landscapes decreased rapidly when the landscape extent was increased. This decrease of variation occurs on surprisingly small scales; the forest landscape structure is unintentionally altered due to small-patterned land ownership, even age distribution of managed stands, and small variation in regeneration patch size. In terms of related landscape metrics, we also compare our results with patterns achieved in randomly generated neutral landscape models.