Collaborative approaches at the landscape scale increase the benefits of agri-environmental measures for farmland biodiversity

Ecological focus areas (EFAs) are a key element of European agri-environmental measures, which aim at mitigating the negative impact of intensive agricultural practices on biodiversity. They are mostly implemented at local scale, such as action-based EFAs (prescribed minimum biodiversity-friendly management) and result-based EFAs (prescribed minimum biodiversity outcome). Implementation at the landscape scale as part of a collaborative landscape-targeted approach is less frequent. There, farmers of a given region jointly determine where and which measures are implemented in order to create a biodiversity-friendly landscape. The effectiveness of the three different, but often intertwined approaches to promote farmland biodiversity, has hardly ever been studied. To this end, we analyzed data from 121 1-km2 squares distributed across the Swiss agricultural landscapes. At local scale (10-m2 units), we found that plant species richness was higher in all EFA categories compared to management units outside EFAs, but tended to be highest in result-based and in collaborative landscape-targeted EFAs. At landscape scale (1-km2 units), plant species richness was positively related to a large total area of all EFAs, while butterfly and bird richness were positively related to a large total area of all EFAs with a high share of collaborative landscape-targeted EFAs. We conclude that while result-based, and especially collaborative landscape-targeted EFAs come along with higher transaction costs, they contribute substantially to farmland biodiversity at different spatial scales.