D3206: The insect community ecology of urban community gardens

As community gardens become more prevalent in urban areas, an integral but often overlooked topic is the intersections among urbanization, socioeconomics, and insect communities. Insect communities include pollinators, herbivore pests, and beneficial predators that control pest populations, all of which could have important consequences for plant productivity. Biodiversity in urban areas is often subject to the “luxury effect,” a term describing how biodiversity is positively correlated with socioeconomic conditions. While this phenomenon has been studied in urban plants, only one study has explored this in arthropod communities, and no studies have examined this phenomena in the context of community gardens. There is a knowledge gap in understanding how urban garden success is affected by insect community composition and how those communities are affected by urbanization and other socioeconomic conditions.

For this research we evaluated how gradients in urbanization and neighborhood socioeconomic conditions impact insect community composition and consequently garden productivity in seven community gardens occupying a range of urbanization gradients. Insect communities were sampled throughout the summer of 2022 using five different sampling methods to capture the biodiversity present in the gardens. Capsicuum anuum (pepper) plants were also placed into the garden sites to get an estimate of the pollination services provided at each garden site. The results of this research are important for demonstrating how maintaining diverse insect communities may be necessary for reliable pollination and pest control ecosystem services for an increasingly urban human population.