Bee diversity on urban rooftop food gardens
Riehn J.K., Fogel N.S., Hathaway J.N., Camilo G.R.
Frontiers in Sustainable Cities, 5:1100470
Urban Farm DB summary
Surveyed bees on three urban rooftop food farms and two nearby ground-level community gardens in St. Louis during 2017–2018. Rooftops hosted 38 species—a nested subset of ground-level communities, with fewer bumblebees and more non-native Megachile—with implications for pollination services on rooftop food production.
Key points
- 138 bee species were found utilizing urban rooftop food farms.
- 2Rooftop bee communities had lower abundances of Bombus species compared to ground-level sites.
- 3Non-native cavity nesters in the genus Megachile were overrepresented on rooftops.
- 4Rooftop bee communities represent a nested subset of the species found at ground level.
- 5Shifts in bee community structure on rooftops have implications for managing green roofs for crop cultivation and determining which crops receive adequate pollination.
Extracted facts
3 factsOnly numbers and their conditions are stored, as structured data — never the source's own sentences. Metric and condition names stay in English, as coded.
- 38 species
bee species richness(rooftop food garden)
Biodiversityn = 3- region
- US-MO
- city
- St. Louis
- setting
- urban-rooftop
- years
- 2017-2018
- sites
- three urban food roofs
- lower on rooftops↓ Decrease
bombus abundance(rooftop food garden)
BiodiversityControl: two nearby ground-level community gardens- region
- US-MO
- city
- St. Louis
- setting
- urban-rooftop
- years
- 2017-2018
- overrepresented on rooftops↑ Increase
megachile representation(rooftop food garden)
BiodiversityControl: two nearby ground-level community gardens- region
- US-MO
- city
- St. Louis
- setting
- urban-rooftop
- years
- 2017-2018
- group
- non-native cavity nesters
Direction of conclusions
Each author conclusion is recorded only as a coded direction per topic. Read the original for the conclusion itself.
- BiodiversityMixedWith caveats
Abstract and stored text
OpenAlexGreen infrastructure on rooftops in urban areas can enhance important ecosystem services. In addition to mitigating water runoff and regulating building temperatures, green roofs can provide food and nesting resources for wildlife. Rooftop gardens can also be utilized to cultivate food crops, giving them the potential to attenuate instances of food insecurity which are commonplace in many urban areas. Given that many crops depend on bee pollination, it is imperative to characterize the rooftop bee community. Therefore, we sampled three urban food roofs near downtown St. Louis, MO during the 2017 and 2018 growing seasons. We found 38 bee species utilizing the rooftop farms. We then compared the rooftop bee communities to those of two nearby ground-level community gardens. The roofs had lower abundances of Bombus species than the ground-level sites while non-native cavity nesters in the genus Megachile were overrepresented. These results indicate that the rooftop bee communities represent a nested subset of the species found at ground level. This has important implications for the management of green roofs for growing crops, as this shift in bee community structure may play a role in determining which crops can be adequately supported with pollination services.
Why it matters for urban farming
This study highlights that bee communities on urban rooftops differ significantly from those at ground level, with fewer bumblebees and more non-native cavity-nesting bees. For citizen-driven urban farms, this means that crop selection for rooftop gardens should consider these specific pollinator populations to ensure effective pollination. Understanding the local bee diversity can help urban farmers choose crops that are well-suited to the available pollinators, maximizing yields and supporting local biodiversity.