Contrasting responses of taxonomic diversity and functional groups of birds to the agricultural landscape of southern Chile

Agricultural landscape heterogeneity, especially the presence of semi-natural habitats, is likely to influence bird diversity positively. In this study we tested how the diferent structural elements of the farmland mosaic affects bird diversity (richness and abundance) and functional groups and their potential provision of ecosystem services in the agroecosystems of southern Chile. For that we counted birds visually and acoustically at 164 counting stations and each bird sighting was related to the vegetation cover at the local scale (200 m radius) and the landscape scale (450 m radius). We observed 3960 individuals covering 50 bird species. From a taxonomic perspective, pastures and tree-structured green lanes showed greater bird abundance and species richness than forested habitats: continuous woodlands, riparian forests, and forest fragments. Regarding functional groups, while forest habitats were mainly represented by specialized frugivores and insectivores, isolated trees and shrub field boundaries were associated with granivorous species, and forest fragments and continuous forest had a strong relationship with species classified as intermediate forest dependence. Habitat heterogeneity did not influence the bird´s abundance and richness, at the local or landscape scales. Native forest remnants are key elements in supporting a high diversity of insectivores and habitat generalist birds. In this study, we highlight the importance of diverse habitat types in maintaining high taxonomic diversity and key functional groups of birds, which could provide regulation ecosystem services by suppressing pest insect populations in the agricultural landscape of southern Chile.