Effects of Swiss agri-environmental measures on arthropod biodiversity in arable landscapes

Abstract

Our study aimed at evaluating the impacts of an agri-environment measure implemented in Swiss arable landscapes, the wild flower strips, on the diversity of arthropods (butterflies, spiders and carabid beetles). We tested whether (i) wild flower strips harbour a higher arthropod diversity than conventional fields and (ii) arthropod diversity is enhanced by wild flower strips at the landscape scale. Wild flower strips had more arthropod species and typical set of species as compared to conventional fields, but they had similar or lower activity-density of epigeic arthropods. The percentage cover of wild flower strips in the landscape context had a positive influence only on carabid assemblages, reflecting an effect of extensification measures at the landscape scale for carabid beetles. For each arthropod group, the efficiency of wild flower strips might also vary according to the presence of conventional grasslands or crop fields in the surrounding landscape.