Distribution of carabid beetles within wildlife corridors connecting fragmented forests

Abstract

We identified wildlife corridors as linkages for carabid migration between two fragmented forests. Three wildlife corridors, constructed in 2007 to connect two forests fragmented by a two-lane road in South Korea, were selected. We collected 982 individuals of 13 carabid species from the wildlife corridors and connected forests. Carabid diversity in the forest sites was significantly higher than in the wildlife corridor sites. The number of individuals of carabid beetle species within wildlife corridor sites was significantly correlated with flight capacity of the species. Carabid beetles were concentrated closest to the forest edge, which resulted in a steady decline in carabid richness and number of individuals further away from the edge of the forest fragment to the center of the corridor, because environmental variables in the corridor were not comparable to those of the forest fragments. Canonical correspondence analysis revealed that trap sites were clearly divided into forest fragment and wildlife corridor sites. Carabid preference for forest habitat was strongly associated with tree cover, whereas their preference for corridors was correlated with exposed areas and grass cover, respectively. Thus, in forested regions, wildlife corridors with dry grassland or open areas provide a heterogeneous habitat for carabids.