1st Place: Reclaiming vacant land to support stormwater management and bee habitat

Urban green spaces provide important wildlife habitat and ecosystem services. In post-industrial legacy cities, built structures are demolished as people leave, resulting in vacant land. Vacant land constitutes an opportunity to establish green infrastructure (GI) that promotes local food production, supports stormwater management, and provides wildlife habitat. Our objective was to determine whether GI established for stormwater management could also serve as insect habitat in the legacy city of Cleveland, Ohio, U.S.A. Two green infrastructure treatments were implemented on vacant land in Cleveland, Ohio in 2014 and 2015: rain gardens and bioswales. Rain gardens were mulched depressions containing water tolerant forbs, grasses, and trees. Bioswales were larger, highly engineered gardens seeded with a variety of native perennials, grasses, sedges, and trees. Bioswales also involved substantial changes to site hydrology. We hypothesized that investments in low-cost (rain garden) and high-cost (bioswale) green infrastructure could enhance local insect biodiversity. Insect pollinators and predators were sampled during the summer (June-August) from 2014 to 2016 using pan traps and yellow sticky card traps. Vegetation variables including bloom abundance, bloom richness, and average vegetation height were measured. Generalized linear mixed effects models evaluated whether insect biodiversity varied with treatment, habitat variables, site, and time of observation. There were no significant differences in bee or predator abundance with treatment. Similarly, we did not find any significant differences in bee diversity or richness. Our results suggest that in the short term, GI can improve stormwater management without compromising the quality of a habitat patch as insect forage.