Effects of grass management intensity on ground beetle assemblages in rice field banks

Within the framework of a general decline in farmland biodiversity, sustainable management of field boundaries and margins has been widely recognized as one of the key approaches for incorporating conservation strategies within agronomic practices. The creation and sympathetic management of edges could improve abundance, diversity, and functional composition of farmland communities. Moreover,many species of arthropods inhabiting these habitats are natural enemies of crop pests and could play a valuable role in biological control. The aim of this research was to investigate the response of ground beetle assemblages to different management regimes in the rice field banks of an intensive agricultural area of northern Italy. Between May and November 2010, we collected carabids in 13 paddy banks (5 uncut, 4 mown twice, 4 cut monthly during June–September) by means of pitfall traps. Frequent cutting operations favoured assemblages dominated by generalist, mobile species, while more specialized ground beetles, such as predatory and short-winged ones, were associated with an absence or low levels of human disturbance. Our results suggest that environmentally friendly managed banks could help to ameliorate the persistence of species with poor dispersal ability and predator populations. Management implications for ground beetle conservation in rice ecosystem are discussed.