Comparison of the body size and wing form of carabid species (Coleoptera: Carabidae) between isolated and continuous forest habitats

In this study, we compared the composition and abundance of carabid species according to their habitat affinity, wing form and mean body size between continuous and isolated forest areas. Investigated plots were located in temperate forests of Mt. Medvednica that represent an island of forest embedded in a lowland matrix of urban ecosystems, agricultural fields and meadows and in similar forest types in large, continuous montane forests in the Gorski kotar area. Data for the proportions of species traits and habitat affinities of 10 plots were compared using principal component analysis (PCA) and nested ANOVA followed by post Hoc tests. We found significant differences between the proportions of forest specialist and generalist carabids and in the morphological characteristics of carabid communities between isolated and continuous forest areas. Isolated area had less forest specialists and more generalist species than large, continuous forest. More macropterous species were present in isolated habitat and more brachypterous in continuous forest area, especially medium-sized brachypterous beetles. Higher proportions of small-sized carabids were present in isolated area and large species were more common in continuous forest areas. Our results suggest that the power of dispersal is an important factor that can be used in analyses of isolation effects on carabid assemblages, not only at small scales, but at larger scales as well, showing the uniqueness of large, continuous forest areas.