Landscape homogenisation and simplified butterfly community structure go on par across Northern Austria

Abstract

Context Agricultural intensification has led to strong homogenization of landscapes. Field copses have become larger, the boundaries between habitats became sharper, and land plots have been cultivated more intensively. In parallel, most field copses, ruderal areas and hedgerows were removed. As a result, ecotones and rarely used microhabitats largely disappeared. In consequence, many suitable habitats for species such as butterflies vanished and the permeability of the landscape decreased, with negative effects on biodiversity. Objective In this study we analyse land-use and habitat configuration, and butterfly diversity for the years 1953 and 2018 for northern Austria. Methods We assessed land cover and landscape configuration for the years 1953 and 2018 on a field-by-field basis across northern Austria, based on aerial and satellite images. We studied butterfly diversity for these two identical periods of time. Results Our data show a decrease of the number of field copses over the past decades and a reduction in landscape complexity. The expected number of butterflies per sample unit of an assumed species decreased significantly. Particularly sedentary specialists decreased, while the proportion of mobile generalists increased. Conclusions Our study underlines the general trend of landscape and faunal homogenization, which specifically leads to the vanishing of extensively used micro-habitats and the loss of sedentary specialist species.