Carabid assemblages in fragmented sandy grasslands

Effects of fragmentation on carabid assemblages were studied in sandy grassland patches in eastern Hungary. Relationship between the habitat characteristics (area, isolation and shape) and the species richness of carabid assemblages was examined by forward stepwise multiple linear regression analysis. The total number of the collected carabid species correlated negatively with grassland area. Overall carabid species richness increased as the isolation of patches increased. The importance of the habitat specific carabid species in the assemblages (expressed by the ratio of the number of open-habitat species associated with sandy soils to the total number of species) increased with patch size. These patterns could be explained by the influx of species entering from the surrounding matrix and edge habitats causing elevated overall species richness in habitat patches with limited size or higher degree of isolation.