Assessment of the biomass of forage macrophytes in a model habitat of the Eurasian beaver (Castor fiber Linnaeus, 1758) (Castoridae, Mammalia) in the State Nature Reserve “Volga forest-step”

The paper is devoted to the resource capacity of habitats of the Eurasian beaver (Castor fiber L.), an invasive species. Insufficient forage supply is a deterrent to the expansion of the range of this species, which has been actively settling in Eurasia in recent decades. Complexes of herbaceous wetland plants (macrophytes) under certain conditions can be a significant source of feed for these animals. However, at the edge of the range, which is currently limited to the forest-steppe zone in the south, the lack of development of aquatic macrophytes could lead to containment of the settlement of this species. It is shown that the conducted studies are important from the viewpoint of forecasting the stability of populations of the Eurasian beaver in the forest-steppe zone, assessing changes in their structure and abundance, and determining the limits of possible expansion of the species' range.