Principles of ecological restoration of boreal forested ecosystems: Finland as an example

Abstract

The degree of past and present human infl uence varies considerably in different parts of the circumboreal forest zone. Almost natural boreal forest dynamics still prevail over considerable areas in many regions of northern Canada and Russia. On the other hand, in regions like the southern parts of Scandinavian countries, forest ecosystems have been fundamentally altered by past utilization and are now almost totally regulated by management. In these ecosystems, natural disturbances only play a minor role in forest structure and dynamics. For example, in southern Finland this is the case not only in managed forests, but also in many protected areas that have a long history of extensive utilization (Working group ... 2000). This constitutes a problem for conservation, since in addition to the small area of protected forest, the value of reserves as a habitat for naturally occurring species has also been reduced because of habitat degradation. In this situation ecosystem restoration can be used to accelerate the formation of structural and habitat features resembling those of natural forests in order to enhance the conservation function of both protected and managed forests. It is evident that in areas that have been strongly affected by past and present forest utilization, including southern Finland, extensive restoration of both managed and protected forest ecosystems is needed if we want to bring these ecosystems closer to their natural level of biological diversity (Working group ... 2000). In 1999, the Ministry of Environment commissioned a working group to evaluate the current state of forest protection in southern Finland. The commission report (Working group ... 2000) lists a number of measures that should be taken to improve the protection situation. The recommendations include: 1) additional conservation of poorly represented forest types, such as herbrich forests and spruce mires, 2) restoration of forests both within protected areas and managed forests surrounding them, 3) formation of larger conservation networks around the existing core