On the negative role of beavers in the area of human economy

The article summarizes some studies and observations related to the negative impact of beavers on human economy. The consequences of beaver activity were registered in forestry, on artificial waterways (drainage ditches), and streams near utility lines. It is established that in the south of Karelia beaver foraging activity results in the loss of 23,2 to 92,1 % of aspen, 3,0 to 26,5 % of birch from the riparian plant community. Beaver dam construction induces development of the new type of communities. However, the damage to forestry is assessed as insignificant. The secondary waterlogging of reclaimed lands was assessed as consequences inflicted by the beavers’ activity on drainage ditches. In northern Karelia, under the deficit of feed, more than 50 % of beaver colonies cling to highways, railways, power lines, areas offering better food resources for beavers when compared to natural habitats. Southern districts of Karelia offer better feeding conditions for beavers, as a result their population density along roadsides is lower than in the north. The article contains cases of beaver damage caused to human facilities, including: flooding of roads, lines of border engineering infrastructure, farmlands, and disconnection of power lines due to the falling of gnawed trees.