Management Intensity and Forest Successional Stages as Significant Determinants of Small Mammal Communities in a Lowland Floodplain Forest

The conversion of forests from complex natural ecosystems to simplified commercial woodlands is one of the major causes of biodiversity loss. To maintain biodiversity, we need to understand how current management practices influence forest ecosystems. We studied the effects of forest successional stage and management intensity on the abundance, species richness, and assemblage composition of small mammals. Our results show that management intensity significantly contributes to reducing the number of species after clearcutting. We revealed that intensively managed clearings can make the dispersal or foraging activity of small mammals difficult and hence negatively influence their abundance and species richness. The significantly higher species richness of small mammal species was recorded within more extensively rather than intensively managed clearings. In contrast, we did not observe significant changes in species richness and abundance after intensive management in old-growth forests. Species Clethrionomys glareolus and Apodemus flavicollis reached the greatest abundance in old-growth forest patches. On the other hand, Microtus arvalis and Microtus subterraneus were species mainly associated with the successionally youngest forest stands. Our analysis suggests that intensive management interventions (i.e., vegetation destruction by pesticides and wood debris removal by soil milling) in clearings produce unhostile environments for majority of the small mammal species.