Each year, Journal of Applied Ecology awards the Southwood Prize to the best paper in the journal by an author at the start of their career. In this post, Katie Turo discusses her shortlisted paper which assessed local- and landscape-scale drivers of bee community composition and foraging within vacant lots of Cleveland, Ohio, USA.
Our cities are home to diverse bee communities and even rare bee species. As a result, urban conservation has been endorsed by policy papers and researchers for its potential to address global bee decline. But what does a high-quality urban bee habitat look like? And how should we manage urban greenspaces to achieve bee conservation goals? For cities to evaluate and achieve their conservation potential, we first need evidence for how bee communities respond to urban habitat installations.
Together with my colleagues at The Ohio State University, we established 56 new pollinator habitats in a city-wide, replicated conservation experiment in Cleveland, Ohio, USA. Such a large-scale manipulative experiment is rare in urban ecology, and this research is the first to quantify how city-wide native habitat installations influence bee communities. Our study is especially relevant to the hundreds of post-industrial cities worldwide that have an overabundance of vacant land and are well-placed to develop urban conservation habitats.
In Cleveland, we evaluated seven unique urban greenspace designs, replicated across eight inner-city neighborhoods. We collected bees with pan and malaise traps and quantified several bee community traits, diversity, and abundance. Additionally, we hand-vacuumed bees foraging on flowers to assess what resources within flowering habitats were used most frequently.
Over several years, we identified key recommendations for creating pollinator habitat in urban areas: First, cities need to consider where to place new habitats within the urban landscape. We found richer bee communities and increased occurrence of smaller bees, such as Lasioglossum spp, when a larger patch of greenspace was within a 1500m radius of a site. We think this may result from increased ground nesting resources occurring in larger, refuge patches within the urban landscape. Furthermore, since this research was published in 2021, we have reinforced our results with similar findings, discovering that large greenspace patches provide valuable habitat for urban bee communities.
Secondly, we discerned that urban weeds attract rich bee communities, independent of a greenspace’s design. For example, we predominately hand-vacuumed bees across all sites from weeds like chicory, red clover, and Queen Anne’s lace. For chicory in particular, foraging occurred at even greater frequencies than the relative abundance of chicory blooms within a site, signaling that bees preferentially forage on these weeds.
Ultimately, our study affirms the value of pollinator conservation in urban areas and indicates that landscape placement can strongly affect a habitat’s value in supporting functionally diverse bee communities. Based on our findings, we suggest the following actionable steps for cities looking to support their pollinators: (1) wherever possible, greenspace should be consolidated into larger patches, and (2) cities should employ infrequent weed management or designate spaces where weeds are allowed to grow.
Katie Turo is a USDA NIFA Postdoctoral fellow at Rutgers University in New Brunswick, NJ. Her research focuses on the local and landscape processes influencing native bee diversity, foraging, and fitness. A central theme of her work is reconciliation ecology, or the advancement of land management strategies to satisfy human needs while preserving healthy ecosystem functioning. During her PhD at The Ohio State University, Katie’s work focused on cities’ potential for pollinator conservation and how urban greenspace management could optimize native bee biodiversity and nesting success. At her current position, she is using pollen metabarcoding to characterize the spring foraging patterns of forest-associated bees. As many forest bee species are critical pollinators for spring blooming crops (e.g., apple, blueberry, cherry), she hopes to identify synergistic ways to conserve forest bees and support crop pollination services.
Read the full paper Conservation in post-industrial cities: How does vacant land management and landscape configuration influence urban bees? in Journal of Applied Ecology
Find out more about the Southwood Prize early career researcher award here.