Influence of the Activity of the Eurasian Beaver Castor fiber (Castoridae, Mammalia) on the Ecosystem Biodiversity of Small Rivers in the Forest–Steppe Zone

Resumo

Abstract—Preliminary data on the impact of the activity of the Eurasian beaver on the ecosystem biodiversity of small rivers in three steppe areas within the Privolzhskaya Lesostep’ State Nature Reserve in the Khoper River basin were obtained. With zooplankton, amphibians, and fish as examples, it was shown that after beaver-made ponds had appeared, the abundance of all these groups increased. In old ponds, the fish abundance decreased while that of amphibians continued to increase. In drained ponds, the zooplankton and amphibian abundance decreased while fish became more numerous, due to the appearance of better flowage.