Understanding biodiversity patterns under the emergence of urban megaregions

Abstract Urban megaregions are polycentric, highly connected networks of urbanised nodes. Human management and landscape hyperconnectivity make these systems fundamentally different from individual cities and other urban regions. Here, we present the ‘Urban Megaregion Amplification Hypothesis’, describing patterns that emerge at the regional level due to feedbacks between energy inputs and organism dispersal facilitation. These feedback loops amplify ecological processes and alter biodiversity patterns. We put forward 6 predictions: the urban megaregion metacommunities are structured under the mass effects paradigm; biodiversity increases within nodes but communities across the megaregion become more similar; gene flow increases and the gene pool is homogenised; trophic networks simplify and rely on human subsidies with mesopredator release; and temporal dynamics are altered by energy inputs and human management.