Application of Island Biogeography Theory in Designing Urban Biodiversity Reserves

Abstract

The application of Island Biogeography Theory (IBT) enhances urban ecological planning by offering a framework to promote biodiversity in fragmented urban landscapes. IBT was initially designed to explain species richness on isolated islands, but provides information about how size, isolation, and connectivity affect colonization and extinction rates of species—conditions that are relevant for urban green spaces functioning as habitat "islands". In this study, we investigate how the design of urban biodiversity reserves can be improved to incorporate IBT principles better, thereby increasing patch size, reducing isolation by implementing ecological corridors, and facilitating species migration to surrounding patches. Upon synthesizing existing case studies and performing spatial analyses of the existing urban green infrastructure, we demonstrate that, in general, larger and better-connected reserves are associated with higher species richness and greater robustness; smaller, isolated patches are more susceptible to extinction. This work compels us to emphasize that implementing ecological principles within an IBT framework in urban planning can help mitigate habitat fragmentation and effectively utilize our green spaces for maintaining urban ecosystems. More broadly, we have also proposed a model for urban reserve network design that may help aggregate competing human ties while supporting ecological connectivity. Applying IBT principles to urban areas enables urban landscapes to play a crucial role in conserving native biodiversity and supporting global conservation objectives amid rapid urban development and climate change.