The intensification of agricultural practices has led to an alarming decline in farmland biodiversity. With the aim of stopping and even reversing this trend, biodiversity promotion areas (BPA – formerly named «ecological compensation areas») were introduced in the 1990s. In this study, the influence of BPA on the biodiversity of butterflies and breeding birds was investigated in 46 landscape squares of 1 km2. If the proportion of BPA in the landscape increased from 5 % to 15 %, the butterfly species richness increased by 22 % and that of birds by 10 %. In the case of birds, farmland and AEO (agriculture-related environmental objectives) priority species primarily benefited from BPA with high ecological quality, though these were rare in most landscapes. For both taxonomic groups, the proportion and quality of BPA habitats was more important than their spatial configuration, including the distances between them. Our study at the landscape scale illustrates the important role of biodiversity promotion areas and highlights their positive effect on biodiversity in the intensively farmed Swiss agricultural landscape.
Biodiversity promotion areas: increasing their proportion and quality benefits birds and butterflies