Shifts in ground-dwelling predator communities in response to changes in management intensity in Alpine meadows

Abstract

Land-use changes, especially agricultural intensification has increased in the last decades leading to a decrease in biodiversity. In Europe, grasslands have been influenced by humans for centuries and millennia and management intensity has increased since the 20th century. In this small-case study, we investigate how management intensity affects ground-dwelling predators in montane hay meadows in South Tyrol, an Alpine region in Northern Italy, using the pitfall trap method. As expected, species composition differed significantly when comparing the predator communities of extensive and intensive meadows, with the former supporting a higher predator species richness, and the latter showing higher proportions of frequent and euryoecious species. Regarding their activity densities and Shannon diversity, we did not find clear differences. Investigating selected ecological species traits, we found differences for moisture requirements and ecological tolerance between the two management types, with xerophilous species being more abundant in the extensive meadows, and stenoecious species more abundant in intensive meadows. In this study, we found management intensity of montane grasslands to have a limited influence on the biodiversity patterns of ground-dwelling predators. However, individual predator groups showed clear reactions to the intensity of management (i.e., decrease or increase in activity density, species richness and Shannon diversity). We conclude that a intensive management of grasslands in combination with local habitat specifics does not lead to a homogenisation of the predatory arthropod community like it was found in other studies. Our study contributes to a better understanding of scarcely investigated predator communities and their diversity in differently managed Alpine grasslands.

Keywords

• Soil
• Arachnida
• Coleoptera
• Formicidae
• species diversity