Resource diversity and landscape-level homogeneity drive native bee foraging

Given widespread declines in pollinator communities and increas- ing global reliance on pollinator-dependent crops, there is an acute need to develop a mechanistic understanding of native pollinator population and foraging biology. Using a population genetics approach, we determine the impact of habitat and floral resource distributions on nesting and foraging patterns of a critical native pollinator, Bombus vosnesenskii. Our findings demonstrate that native bee foraging is far more plastic and extensive than previ- ously believed and does not follow a simple optimal foraging strat- egy. Rather, bumble bees forage further in pursuit of species-rich floral patches and in landscapes where patch-to-patch variation in floral resources is less, regardless of habitat composition. Thus, our results reveal extreme foraging plasticity and demonstrate that floral diversity, not density, drives bee foraging distance. Further- more, we find a negative impact of paved habitat and a positive impact of natural woodland on bumble bee nesting densities. Over- all, this study reveals that natural and human-altered landscapes can be managed for increased native bee nesting and extended foraging, dually enhancing biodiversity and the spatial extent of pollination services. dispersal | ecosystem services | resource dynamics | spatial ecology | urban