Pollinator community structure in the shrinking city

Background/Question/Methods

Urban biodiversity is a rising area of interest but little is known about bee diversity and how it responds to urban and inner-city environments. With urbanization increasing worldwide, and bee populations declining is essential that we understand how these factors are related. Previous studies have tried to understand how classical ecological process (ie, species-area, competition, etc) influence pollinator communities in urban environments.  We propose that other forces, like socio-economic status and ethnic composition, also play significan role in shaping pollinator communities in urban systems. We sampled a range of community garden in St. Louis city. These gardens were occurred in a range of socio-economic (from low to middle high), and ethnic (mostly black to mostly white) neighborhoods. Sampling was done in a systematic fashion and took place bi-weekly from mid May to late September 2013, and again in 2014. Each session ­lasted­ for 50 minutes and ­included 2-3 individuals sampling for all pollinators using aerial nets.

Results/Conclusions

Over 30 bee species representing four families and thirteen genera were collected. Bee communities were distinct depending on the socio-economic status of the surrounding nieghborhood, both in abundance as well as diversity.  Furthermore, the distribution of individual species were also affected by these variables.  Uncommon and rare species were overrepresented in the more established and diverse neighborhoods, while underrepresented in poorer neighborhoods.  These differences have significant implications for sustainability policies in cities, environmental justice, and even the sourcing of produce from local community gardens.