Факторы, определяющие возможную экспансию речного бобра (Castor Fiber, L.) в центральной лесостепи (на примере Курской области)

Abstract

Studies of the population dynamics of commercial mammal species are necessary both for the conservation of biodiversity and for solving a number of applied issues. The ever-increasing rate of expansion of the river beaver in the central forest-steppe necessitates long-term monitoring. This is all the more relevant since official sources indicate the number of beaver within 1–2 individuals/km of watercourse, while according to our data, it is at least 10–12 individuals/km. The aim was to determine the influence of climatic and anthropogenic factors on the sharp increase in the number of European beaver in the most typical wetland systems of the rivers of the Dnepr and Don basins (Seim, Psel, Oskol, Sosna). To count the number of the river beaver, a statistical method was used, supplemented by a cartographic one, with the creation of maps using geoinformation technologies. The results obtained show that the increase in the number of beavers is due to the temporary coincidence of favorable climatic factors against the background of minimal fishing pressure. Thus, the simultaneous significance of two main hypotheses is emphasized: “cyclic-trophic” and “anthropogenic-predatory”, the influence of which on commercial mammals is considered separately. The fundamental significance for the "explosive growth" of the beaver populations of the onset of the warm-dry phase of the secular cycle is shown. Based on the data obtained, a conclusion was made about the fundamental influence of the two-factor system on the state of beaver populations in the central forest-steppe. Keywords: RIVER BEAVER, CENTRAL FOREST-STEPPE, KURSK REGION, GIS IN GEOECOLOGY