EFFECTS OF MOOSE DENSITY ON TIMBER QUALITY AND BIODIVERSITY RESTORATION IN SWEDEN, FINLAND, AND RUSSIAN KARELIA

Abstract

A long history of forest use and management in Sweden has promoted conifer-dominated forests at the expense of deciduous trees such as Populus tremula, Salix caprea, and Sorbus aucuparia. Moose (Alces alces) area a key species to both with respect to the maintenance of biodiversity associated with these deciduous trees and to the production of good quality Scots pine (Pinus sylvestris) timber. For biodiversity of there is a need to restore the deciduous forest component, which is also the preferred food of moose. If the moose/preferred food ratio is too high and hence browsing on the preferred tree species is too intensive, this restoration can be difficult. To study the interactions between the abundance of preferred moose food, moose density, and damage to trees, it is necessary to include landscapes with a broader combination of food abundance and moose density than found just in Sweden. This is necessary as the landscape and management situation in Sweden in rather homogenous, with the same policies concerning forestry and moose management having been implemented. To cover a wide range of relevant factors, a studying covering 8 landscapes in Sweden, Finland, and Russian Karelia was carried out in autumn 1998. Damages on both preferred trees and Scots pine in pine-dominated stands were correlated to moose density. Damages were most severe in Sweden, intermediate in Finland, and least in Russian Karelia. Moose winter densities ranged from 1.7/km² in Sweden to 0.2/km² in Russia. The cover of preferred foods (Populus/Salix/Sorbus) increased 13-fold from Sweden to Russia. As a consequence, the proportion of severely damaged and dead individuals of the preferred species increased 36-fold from the least to the most affected landscape. Similarly, damages on Scots pine in pine-dominated stands ranged from 57% in Sweden to 7% in Russian Karelia. Unless damage by moose is reduced in Sweden in the landscapes that we studied, it is doubtful that deciduous vegetation can be maintained, thereby affecting biodiversity. Communication with stakeholders is essential if this socio-economic problem is to be resolved. One feasible model may be co-management case studies based on a holistic landscape view and objective inventory of perceived problems among all stakeholders.