Cology of root vole (Microtus oeconomu Spall.) in anthropogenic landscape of Karelia

Numerical strength of Karelian root vole is much weaker than the strength of other species in the species area. (The average longstanding data amount to 0,23 rouges per 100 trap-days) The phenomenon is conditioned by the limited distribution of appropriate biotopes (grassy swamps and numerous forest water basins covered by sedge grass) and poor availability of nutrition. The most characteristic features of the root vole habitat distribution in the taiga zone are its absence in the soft wood forests, on the one hand, and its distribution tendency toward grassy clear cuttings, on the other hand. Therefore, clear-cutting of the forest can lead to a significant increase of the root vole numerical strength especially when such cutting areas are located close to the natural habitat (bottomland meadows, willow shrubs, and ets.) of the studied species. The basic reasons for lasting fluctuations in species' numerical strength are seasonal meteorological factors, which define wintering and fertility level of the population, and availability of sufficient nutrition.