Impacts of management at a local and landscape scale on pollinators in semi-natural grasslands.
Abstract
Managing farmland to benefit biodiversity is becoming increasingly necessary to combat biodiversity declines and maintain ecosystem services. Results-based agri-environmental schemes are a tool used to achieve this by paying farmers based on environmental results delivered. These schemes often utilise plant indicator species to assess results at field scale; however, it is unknown if focusing on enhancing a subset of one biodiversity group within results-based schemes impacts wider biodiversity, and whether local-scale implementation of results-based schemes or/and the wider landscape are more important drivers of biodiversity patterns. 2. Insect pollinators provide important pollination services for many crop and wild plants, and as mobile organisms often experience landscape at large spatial scales. We tested whether insect pollinators are affected at local scale by a results-based scheme scored based on plant indicators, or if landscape management is more important, and whether there were different responses between taxon-specific groups. Bumblebees, solitary bees, hoverflies and butterflies were sampled using transects and pan traps in 23 fields with varying scores assigned by the scheme, situated in high-intensity (≥65% improved grassland) or low-intensity (≥65% semi-natural grassland) landscapes. 3. Results indicate taxon-specific responses to local and landscape management in semi-natural grasslands. Bumblebees responded positively to local-scale management in fields with higher floral diversity, whereas hoverflies and butterflies responded positively to low-intensity landscape management. 4. Synthesis and applications. Using plant species as indicators for biodiversity in agri-environment schemes can have indirect benefits for non-target taxa like bumblebees, but broader indicators should be developed to incorporate other pollinator groups. Pollinator groups respond differently to local and landscape management in semi-natural grasslands. Agri-environmental management should consider a range of different management measures and landscape scale approaches where possible, to maximise benefits for a range of pollinator taxa.