Species diversity and the scale of the landscape mosaic: do scales of movement and patch size aect diversity?

We use a combination of a model and empirical data to examine the relationship between the scale of the landscape mosaic and individual movement patterns on the measurement of local butter ̄y species diversity. In landscapes where patch sizes are smaller, the type of patch adjacent to the patch surveyed can in ̄uence both local species richness and incidence. In landscapes composed of larger patches, adjacency has no e€ect on species richness or incidence. We hypothesize that the mechanism for species enrichment is the potential for movement of individuals between habitats, resulting in either (a) spillover of species from the higher-diversity patches into other habitats, or (b) habitat sampling by species that bene®t from the resources in adjacent patches. In order to determine whether landscape con®guration alone can account for the observed patterns of diversity, we employ a simulation model. Simulation results suggest that both specialist and generalist butter ̄ies can sample a much more diverse array of habitat types in a more ®ne-grained landscape. # 2001 Elsevier Science Ltd. All rights reserved.