Distance-decay reveals contrasting effects of land-use types on arthropod community homogenisation

Homogenisation caused by intensive land-use is one of the drivers of global biodiversity decline. However, the contribution of land-use intensity to insect diversity loss is still largely untested. Therefore, we compare the rate of species homogenisation of ~12.000 arthropod species (using Barcode Index Numbers) from 450 families, using distance-decay relationships. We study communities along an increasing local land-use intensity gradient from forests to managed grasslands, to arable lands and to settlements situated within near-natural, agricultural, and urban regional landscapes. Our approach for incidence data under consideration of incomplete samples identifies that grasslands harbour the most homogenous communities after taking frequency and species traits into account. In contrast, the most modified land-use types, settlements, and arable lands do not differ from forests, and showed the most heterogeneous communities between locations. Large- and low-mobility species communities are the most heterogeneous in space, but patterns are dependent on local land-use. Regional landscapes modify the community response to local land-use types: near-natural landscapes reduce homogenisation, while agricultural landscapes increase homogenisation. Based on our findings we recommend enhanced conservation efforts particularly in managed grasslands to reverse homogenisation, while settlements and arable lands could be considered more in arthropod community heterogenisation.