Different ways of maintaining the biodiversity of boreal forests

Raimo Heikkilä

Kainuu Regional Environment Centre, Research Centre of Friendship Park
Tönölä, FIN-88900 Kuhmo, Finland

The biodiversity of boreal forests in Finland has greatly decreased during this century both on habitat and species level. Almost 1000 forest species are regarded as extinct, endangered, vulnerable or in need of monitoring. Most of these species are bound with rare habitats or old-growth forests. At the moment, the main problem in maintaining the biodiversity of boreal forests is the loss and fragmentation of old-growth forests. Especially in the southern half of Finland, in southern and middle boreal vegetation zones, old-growth forests have almost totally disappeared mainly due to intensive forestry in private-owned forests.

The most important way of protecting the biodiversity of forests is establishing nature reserves. At the moment, approximately 3.6% of the forests in Finland have been protected as nature reserves, or included in the EU Natura 2000 -network. Only 2.0% of the forest area are protected old-growth forests, i.e. 35% of the remaining old-growth forests. In southern Finland only 0.1% of the forest area are protected old-growth forests.

In addition to nature reserves, active management of the biodiversity is needed. Especially around small nature reserves consisting of old-growth forest, the surrounding forestry areas should be included and restored to make the protected old-growth forests large enough to preserve the continuity of decaying wood and microclimate in the future in a time scale of 200-300 years.

In state-owned forests landscape ecological planning or the forest utilization was started a few years ago. In landscape ecological plans forestry and conservation of biodiversity as well as recreation are planned simultaneously. The network of nature reserves is supported by forming new small reserves and corridors or stepping stones between the protected habitats. Unfortunately there is not yet a sound scientific basis for this planning in the conditions of boreal forests.

In the new forest act and nature conservation act some rare habitats have been defined as key biotopes to be protected in connection with forestry. Typically these are very small in area, and protect mainly species with unusual edaphic demands. Key biotopes cannot protect the biodiversity of old-growth forests. Nature conservation act also contains a list of specially protected species. It is forbidden to change their surroundings so that important populations of those species would be damaged. Environment administration has a possibility to prevent such activities. So far, the new acts have not really been applied to the problems of the conservation of old-growth forests.