Which bees have it better? Urban or rural bees? For hundreds of years, most people would have said ‘rural bees’ because there was such rich diversity and lush habitat almost everywhere.
Things change over time, and lately it seems life has become easier for city-living bees. The city bee benefits most from specific types of urban ‘greening’ in towns and cities. Turning empty lots into green spaces creates biodiversity island oases within cities that offer gentle reprieve to threatened bees.
There is a cosmetic advantage to converting vacant urban lots into greenspaces. They simply look better for those who see them on a daily basis. This uplifts neighborhoods as well as improving health, moods, and quality of life for everyone in the community. Recent research shows that some such conversion efforts have the added bonus of benefiting bees.
Findings by Ohio State University (OSU) researchers studying ways to encourage biodiversity in vacant urban lots reveal that plots surrounded by 15 or more connected acres of flowering prairies with native flowers and greenspace are beneficial to native bees and predatory wasps. These insects thrive in these ecosystems. Research from the 3-year study is published online in the journal Conservation Biology.
These findings can be very useful to the world's estimated 350 "legacy" cities. These are former industrial hubs whose landscapes changed dramatically due to lost manufacturing industries and depopulation.
This unrelated 10:18-minute video by TED shows similar reimagining of urban public space projects in New York City and Moscow, Russia. While the video is not geared to pollinators, it is easy to see how these projects are well-suited to bringing such native insects into these areas.
Native insects are vital for pollination and the ecosystem, which benefits rural farmland and the growing urban agricultural industry. In Cleveland, Ohio, where the research was conducted, there are over 200 community farms and gardens.
"Both urban and rural farms require pollinators for efficient crop productivity because bee visitations can enhance crop quality and quantity," said Katie Turo, co-author of the study and PhD graduate from OSU's Department of Entomology.
Optimizing bees' city-living conditions helps offset threats to their survival. A wide range of stressors weighs heavily on the bee population -- habitat loss, climate change, pesticides, and invasive species. Turo, now a postdoctoral researcher at Rutgers University, says none of these problems are going away anytime soon.
Some urban "greening" strategies being assessed by researchers support multiple ecosystems and strengthen the insect-plant symbiotic relationship to boost biodiversity. Infrequently mowed turf grass can support insects. Experimental lots included no-mow dense grass lawn, lawn with various flowering grasses, a prairie-like area with tall native grasses, a blend of flowering native grasses and plants on a prairie-type lot with minimum green space management.
“Even in the middle of the city, bees were using these small patches of habitat,” said Mary Gardiner, Professor of Entomology at OSU. She was a key member of the research team. “This is one of the first times a paper has demonstrated that native bees responded with a reproductive benefit from the establishment of native plantings within a city.”
Earlier research revealed that a diversity of various flowering plants in an area was important to such pollinators as bees and bumblebees. Gardiner is excited that the study shows some proportion of the bees and wasp community respond to larger patches of greenspace being created in the landscape, even if it is not the original pre-development natural habitat.
A common solution so far has been to demolish clusters of abandoned buildings and homes and cover the land with turf grass that needs minimal maintenance. Cleveland, for example, lost more than half its population since the 1950s. This led to demolition of unneeded infrastructure and the creation of almost 4,000 acres of vacant land across 27,000 lots.
There are many considerations when greening initiatives are proposed in municipalities. Gardiner and Turo believe their research suggests that thoughtful conservation gives nature a chance to blossom anew in unexpected settings.