A global assessment of animal community responses to agricultural management

Transitions in agricultural management through crop and noncrop diversification on intensively managed croplands or pastures have benefited biodiversity. However, the extent to which agricultural management benefits species communities present in undisturbed ecosystems remains largely unclear. We quantified the animal biodiversity associated with a range of agricultural systems varying in crop and noncrop diversity and compared these with biodiversity associated with undisturbed reference ecosystems (mostly forests). We added data on agricultural management to three large databases-PREDICTS, GLOBIO, and a database compiled by Kuipers et al.-and grouped 107,386 observations from 151 studies into one of nine agricultural classes. We evaluated the animal biodiversity associated with the agricultural class, including the presence of threatened species, based on four biodiversity metrics (intactness, relative richness, compositional similarity, relative abundance). Biodiversity of monoculture annual and perennial croplands was least like that of reference ecosystems across biodiversity metrics. We found small biodiversity benefits of crop diversification and the presence of sparse trees on farmland. Biodiversity in agroforests and silvopastures was the most similar to reference ecosystems, probably due to a high density of trees, resulting in similar vegetation structure and diversity to undisturbed forests. Over time, biodiversity increased in agroforests, whereas the biodiversity of perennial croplands remained stable. Overall, our results suggested that the extent to which species associated with undisturbed ecosystems find refuge in agricultural areas is influenced by agricultural management, but different types of agricultural systems produced varying benefits. The outcomes of our study highlight the potential of introducing agricultural policies that aim to enhance agricultural management through tree planting and crop diversification to accommodate species that inhabit undisturbed ecosystems.