Environmental filtering and landscape composition drive multifaceted diversity of bird assemblages in vineyards.
Abstract
Agricultural landscapes are productive areas with high biodiversity potential, but their conversion to monocultures and intensification of practices are recognised drivers of bird biodiversity loss worldwide. This challenges the compatibility of agricultural land use with bird conservation, as landscape composition affects both the diversity of bird species and traits and the assembly of bird communities. We address the underlying mechanisms of avian community assembly in vineyards at the plot and landscape levels in relation to landscape composition in one of the major wine producing regions of France. We jointly analyse how the taxonomic, functional, and phylogenetic facets of bird alpha and beta diversity respond to a gradient of landscape heterogeneity and test for a non-random assembly rule. We found that birds tended to avoid vineyard monocultures. There was consistent support for the co-occurrence of both closely related species and similar functional traits within vineyard plots (namely, phylogenetic and functional clustering, respectively). Landscape composition, both within plots and on a large scale (1000 m), was critical in explaining the occurrence of species and traits within plots. Landscape composition determined a nested pattern of functional and phylogenetic beta diversity from vineyard monoculture to more complex landscapes with increasing seminatural land cover. Synthesis and applications. Landscape composition in seminatural vegetation features significantly influenced both the alpha and beta bird diversity in vineyard-dominated agricultural landscapes. Interspersed shrubs and woodland can help increase bird abundance and species richness in vineyards, while large-scale land cover diversity might help promote functional and phylogenetic bird diversity.