Commercial harvest of logging residue in clear-cuts affects the diversity and community composition of ground beetles (Coleoptera: Carabidae)

Structural complexity of the habitat is known to influence the diversity and abundance of arthropod populations. Earlier studies have shown that presence of logging residue (slash) on the ground contributes to microhabitat complexity and removal of slash for biofuel in clear-cuts can have short-term (∼1 year) effects on ground-active beetle populations. This study examines the consequences of slash removal on carabids (Coleoptera: Carabidae) 5–7 years after harvest. Sampling of beetles was done by pitfall trapping in three matched clear-cut pairs, in spruce forest in central Sweden. The number and diversity (Berger–Parker dominance index) of carabid species were significantly higher in clear-cuts with slash harvest than in sites where slash was left on the ground. No difference in the overall rank-abundance pattern was found between clear-cuts with different slash treatments, but for species with certain habitat preferences the community was significantly altered. In all clear-cuts, slash removal caused a shift in dominance with an increase in generalist species and a decline in forest species. The results show that removal of slash may have long-lasting effects on the carabid community composition and structure. Hence, in forest landscapes with large-scale biofuel harvest, generalist carabid species may increase their abundance. Following the precautionary principle, it is suggested that every fifth clear-cut should be free of slash harvest.