Land use cover changes the bird distribution and functional groups at the local and landscape level in a Mexican shaded-coffee agroforestry system

Abstract

Land-use changes have affected biodiversity and the role it plays in ecological functioning throughout the Neotropics. It is important to understand the response of species to land-use changes to recommend appropriate management and conservation strategies. This is particularly true when land use systems include agroforestry systems, such as shade coffee plantations. In this study, we evaluated the taxonomic diversity of birds and the effect of land-use types (cattle pastures, shade coffee plantations, and forests in late successional stages) on the presence of functional groups at the local and landscape level in a Mexican cloud forest landscape. We carried out monthly bird surveys for one year in 90 circular points with a radius of 25 m (30 points per land use type) in which we compared bird taxonomic diversity using effective diversity or Hill numbers. We analyzed the composition and abundance of bird species and functional groups across land use types using nonmetric multidimensional scaling and tested the effect of predictor variables on functional group abundance at the local and landscape level using ordination methods and generalized linear models. In total, we recorded 134 bird species belonging to 27 families. Bird species richness was highest in late forests. Bird species diversity was high in both late forests and coffee plantations in comparison to cattle pastures. There was a greater similarity in the bird species composition and functional groups in both late forests and coffee plantations compared to cattle pastures. Bird functional groups favored by more complex vegetation structure included forest granivores, small insectivorous flycatchers, and nectarivores, groups that were also present in more diverse plant communities at the local level and by humid forests associated with shade coffee plantations at the landscape level. Avian granivores associated with disturbed environments were negatively related with vegetation complexity and forest cover across scales and omnivores were positively associated with disturbed areas at the landscape level. This study shows the susceptibility of certain bird functional groups to different land use types at distinct spatial scales and highlights the role of shade coffee plantations as a land use type that maintains taxonomic and functional diversity of birds in Neotropical cloud forests.