Effects of agri-environment schemes in a long-term ecological time series

Abstract

We investigated the impact of agri-environment schemes, including organic farming, on contrasting taxa, when the management of a Southern English farm was changed in the middle of a 12-year time series for an ecosystem-monitoring programme. Plant species richness, including butterfly larval food plants, increased, whilst grassland productivity decreased. There was no overall difference in butterfly or carabid beetle abundance or species richness after the management changes, but some individual species increased significantly. Moth abundance and species richness significantly increased following changes in management. There were significant longer term increases in butterfly and carabid populations from when monitoring started in 1994, which continued through the change in management. This contrasted with national trends over the same period. Warmer summers generally increased invertebrate abundance, but there was no significant trend in weather variables for the years following the change in management. This study corroborates results from short-term comparison of contrasting farms and demonstrates measurable benefits to biodiversity from the implementation of agri-environment schemes, which continue to increase over at least 5 years.