Grazing conserves threatened carabid beetles in semi-natural calcareous grasslands better than mowing, especially at low intensities

Semi-natural grasslands are biodiverse ecosystems that support many threatened species, but they require management interventions to maintain their habitat characteristics. Although many semi-natural calcareous grasslands historically were grazed, mowing is often used as a substitute disturbance when livestock access is not feasible. Mowing may have different effects on vegetation than grazing, but it is unclear if these differences cause changes in animal diversity or grasslands' ability to support endangered species. We studied carabid beetle (Coleoptera: Carabidae) assemblages in semi-natural calcareous grasslands in southern Germany managed with either different intensities of grazing or by mowing. There were no differences in overall activity density, richness, or functional trait diversity of carabid beetles between management methods, but mowing reduced threatened species richness and their proportions in the assemblages. Grazing intensity, measured by livestock faeces density, had little effect on carabid assemblages. The benefits of grazing for threatened species were most apparent in small sites, indicating that using grazing management to conserve endangered beetle species may be particularly important where habitat area is limited, even though these are the sites most likely to use mowing management.