Response of Wild Bee Assemblages and Floral Resources to Management of Restored Wetlands in Central New York, USA

To effectively protect wild bee pollinators and the services they provide, it is critical to understand habitat use patterns across a diversity of cover types. Wetlands are underrepresented in bee surveys, and although wetland restoration produces conservation benefits for birds, it is still poorly known how hydrological management influences bee assemblages and availability of floral resources. In this study, actively (full or partial water drawdowns) and passively managed restored wetlands in central New York were surveyed to characterize plant and bee assemblages, June – September 2019 and 2020. Over 9,000 bees were collected using pan trap and sweep netting methods, representing ≥ 109 species in 25 genera. Environmental variables such as percent open water and mudflat frequency differed among management treatments, but were better predictors of entomophilous plant community composition, bee richness, and/or entomophilous plant richness and occurrence than management treatment alone. Entomophilous plant occurrence varied negatively with invasive graminoid occurrence. Although bee community composition was best explained by phenological turnover, diverse moist-soil flowers in late summer and long-blooming emergent flowers were important to generalists and specialists alike. Emergent wetlands offered valuable supplemental resources for wild bees, making wetland restoration and management a useful pollinator conservation approach. Maintaining a complex of wetlands with differing hydrological conditions, and controlling densities of invasive plants, can diversify and increase resources available for bees, while also meeting management goals for wetland wildlife.