Impact of European Beaver (Castor fiber L.) on Vegetation Diversity in Protected Area River Valleys

The aim of the study was to evaluate impact European beaver (Castor fiber L.) on vegetation diversity and expansion non-native plant species in areas surrounding watercourses Polesie National Park, Poland. investigation carried out within six inhabited by beavers four comparison where were absent. living park had a small excursion range, reaching maximum distance 25 m from watercourse so that effects limited immediate vicinity watercourse. Beaver significantly influenced tall tree forest floor vegetation, while it did not modify low shrub layer. Five alien documented. most strongly associated with activity devil’s beggartick (Bidens frondosa L.), which occurred dams. Other benefiting presence giant goldenrod (Solidago gigantea Aiton) black cherry (Prunus serotina Ehrh.). Our confirmed hypotheses found literature according activities reduce proportion native can promote species.