Pollinator diversity across socio-economic range of urban gardens in St. Louis city

Background/Question/Methods

Pollinators are an important component of ecosystems, providing an essential service for plant reproduction, including food production. Among pollinators, bees are some of the most efficient and diverse members.  This diversity allow for a range of species to go from generalists, like honey bees, to highly specialized, like squash bees (Peponapis spp.).  Unfortunately, little is known about how pollinators respond to inner-city environments.  This is important given the renewed interest in sustainability advocates to develop local food and produce sources within inner city locations. 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. Plantings were almost exclusively vegetables (tomatoes, peppers, pumpkins), fruits (apples, peaches, and berries) and herbs (sage, basil, and various mints). 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. All collected individuals were mounted, labeled and identified to species.

Results/Conclusions

Over 30 bee species representing four families and thirteen genera were collected. Early-mid July to late August was the peak of abundance and diversity. Some notable species include Bombus pensylvanicus, which is uncommon and believed to be in decline in parts of its range, and Bombus auricomus, which is uncommon. Megachile addenda and Megachile frugalis represent new records for St. Louis city. The total bee diversity observed in the garden (alpha diversity) represents 45.6% of the total bee diversity for the area (gamma diversity). Our results have significance for managing ecosystem services across the urban environment of cities