Landscape configuration and diversity hotspots in wintering sparrows.

Community-level studies with finches have traditionally viewed local resources as the primary constrainst on local diversity. Patches have been considered to be self-contained and embedded in landscapes that were neutral with respect to the ecological processes under investigation. This study uses a factorial design to examine the relative roles of patch content and patch context in determining patterns of species richness. Sparrows were surveyed in small fallow patches that varied in both weed cover and the type of adjacent habitat. Species richness and total sparrow abundance were significantly influenced by both factors. Individual species were also influnced by both factors; however, responses were species-specific. Because occupation of particular plot types was conditional on their association with specific habitat types, the spatial patterning of species assemblages results from the configuration of patch types within the landscape.