Agri-environment schemes are associated with greater terrestrial invertebrate abundance and richness in upland grasslands

Agri-environment schemes are a key mechanism by which agricultural sustainability is encouraged by subsidising farmers to adopt environmentally friendly management (e.g. reduction of inputs) to maintain and enhance the delivery of biodiversity-associated ecosystem services. Studies testing the efficacy of agri-environment schemes have yielded varying results, and few have focused on upland (marginal or Less Favoured Area) grassland (> 150 m above sea level) where productivity is poor. This study used a factorial field experiment to examine patterns in plant communities and terrestrial invertebrates between agri-environment scheme and conventionally managed semi-improved and improved upland grasslands, using 90 spatially paired fields. Total plant species richness and rare plant species richness (those with < 10% occurrence) were unaffected by agri-environment scheme management, but were significantly higher on semi-improved than improved grasslands. Total and rare invertebrate abundance and family-level richness were unrelated to grassland type (semi-improved or improved). Total and rare invertebrate abundances were 4% and 218% higher, and total and rare invertebrate family-level richness were 17% and 14% higher in agri-environment scheme than conventionally managed fields, respectively. Here, we show that agri-environment scheme management of marginal or Less Favoured Area upland grassland was associated with higher multi-taxa invertebrate abundance and richness associated with swards indicative of wetter conditions with lower dominance of perennial ryegrass (Lolium perenne) and greater coverage of other native grass species compared to conventional management. This suggests that agri-environment schemes may maintain, enhance or offset declines in terrestrial invertebrates and their associated ecosystem service delivery by maintaining more diverse swards, and suggests that they make a positive contribution to biodiversity conservation.