Herbivore Biodiversity Varies with Patch Size in an Urban Archipelago

The effects of ecosystem fragmentation on biodiversity during urbanization are well established. As a city grows, it replaces much of the native plant life with asphalt, cement, and lawns, yet small patches of native plants remain in greenspaces, which act as refugia for native animals. However, little work has been done on the patterns of re-colonization by native animals as urban decay allows for re-establishment of native plant communities. We found that patterns of biodiversity in the insect herbivore community within an archipelago of abandoned lots follow patterns of island biogeography, with higher biodiversity on large islands. We also found that insect colonization of the abandoned lots was correlated with each species' dispersal ability. The patterns seen here have implications for patterns of species movement into urban systems as new parks are established or as abandoned lots are re-colonized by native plants.