Current research priorities include: 1) Causes of biodiversity. We examine the mechanisms that influence the diversity of species in habitats and how human activities and species invasions alter biodiversity patterns. 2) Consequences of biodiversity. We evaluate the ways in which changes in biodiversity influence the functioning of ecosystems in natural and urban landscapes. 3) Preserving biodiversity. We examine how to conserve and manage natural and urban ecosystems to maximize biodiversity and the ecosystem services that all people benefit from.