Bee Richness and Abundance in New York City Urban Gardens

TLDR

The study describes bee richness, abundance, and ecological traits in Bronx and East Harlem community gardens and compares these findings to other regional surveys. Data were collected over four years, sampling 1,145 bees across 54 species, and the results were benchmarked against surveys from New Jersey and New York State. The survey recorded 1,145 bees from 54 species, with a high proportion of exotic and cavity‑nesting species, low soil‑nesting and parasitic representation, and overall reduced richness compared to other regional studies, yet the gardens still support diverse pollinators that can offer pollination services and educational opportunities.

Abstract

We describe the richness, abundance, and ecological characteristics of bees in community gardens located in heavily developed neighborhoods of the Bronx and East Harlem, NY. In total, 1,145 individual bees, representing 54 species (13% of the recorded New York State bee fauna) were collected over 4 yr. The nesting habits of these species include bees that nest in cavities (33% of species), hives (11% of species), pith (1.9% of species), wood (1.9% of species), or soft/rotting wood (7.4% of species) substrates. Soil-nesting individuals were relatively rare (25% of individuals), perhaps due to a lack of proper soils for nesting sites. Parasitic species were scarce (5.6% of species, 2.6% of individuals), most likely because of an absence or rarity of host species. Overall, exotic species were abundant and constituted 27% of the total individuals collected and 19% of the identified species. We compare these results to several bee faunal surveys in New Jersey and New York State, including newly reported species lists for Central Park and Prospect Park in New York City. Relative to other studies, bee richness of the urban gardens is reduced and composition is biased toward exotic and cavity-nesting species. Nevertheless, despite their small size and location within highly urbanized areas, urban community gardens harbor a diverse assemblage of bees that may provide pollination services and opportunities for ecological exposure and education.