A comparison of ground beetle assemblages (Coleoptera: Carabidae) in conventionally and ecologically managed alfalfa fields

From 2007-2011, the occurrence of ground beetles (Coleoptera: Carabidae) was studied using emergence traps in two differently managed alfalfa fields in the Czech Republic - a conventional and an ecological production system. In total, 784 specimens of ground beetles representing 58 species were trapped in these two alfalfa fields in South Moravia. A slightly higher number of specimens were trapped in the conventionally managed than in the ecological alfalfa stand (404 vs 380, respectively). In the conventionally managed alfalfa stand, the number of species was also higher than in the ecological stand (45 vs 40, respectively). With the exception of 2007 and 2009, Simpson’s indices of diversity were higher in the conventional stand than in the ecological in all study years. Shannon’s index was higher in the conventional alfalfa field in 2008, 2009, and 2011. Regarding distribution, species classified into group E (i.e., those without special demands on the type and quality of their habitat) dominated in both types of management throughout the experimental period. The incidence of species classified into group R (i.e., those with narrow ecological amplitude) was very low; i.e., only four species. These ground beetle species are included in the Red List of Threatened Species of the Czech Republic, and all of them (i.e. Acupalpus suturalis, Calosoma auropunctatum, Cicindela germanica and Ophonus cribricollis) are listed as vulnerable.