Urban Biodiversity and the Importance of Scale

Many ecological and evolutionary processes are affected by urbanization, but cities vary by orders of magnitude in their human population size and areal extent. To quantify and manage urban biodiversity, one must understand both how biodiversity scales with city size, and how ecological, evolutionary, and socioeconomic drivers of biodiversity scale with city size. We show how environmental abiotic and biotic drivers, as well as human cultural and socioeconomic drivers, may act through ecological and evolutionary processes differently, at different scales, to influence patterns in urban biodiversity. Because relationships likely take linear and nonlinear forms, the need to describe the specific scaling relationships is highlighted, including deviations and potential inflection points, where different management strategies may successfully conserve urban biodiversity.