Evaluating citizen science and habitat management for native bee conservation

Abstract

Pollinators across the globe are experiencing population declines at concerning rates. Bees, a particularly important pollinator group, are threatened by many stressors, namely loss of floral resources and parasites are thought to be leading drivers of decline. Land management agencies have been spearheading efforts to restore habitat quality in natural areas through various restoration management techniques such as removal of invasive species, prescribed fire application, and restorative wildflower plantings. These management tools have been shown to improve floral resource availability although gaps persist in our understanding of how they impact bees and their interaction networks. Moreover, environmental attributes in the surrounding local and landscape context influence bee communities, yet little is known about how these factors impact vulnerable species, such as bumble bees. My dissertation research aimed to address these shortcomings through four distinct projects described here in chapters 2-5. Chapter one discusses the current status of native bee conservation, describing factors that threaten bees. Chapter two assesses the use of the citizen science platform iNaturalist for bee research and conservation. We found the platform is a valuable source of open access bee data and can be a useful research tool with consideration of data quality. Chapter three investigates the use of different restoration management techniques applied in a degraded wetland. In this study, invasive shrub removal had a positive effect on floral resources, and variation in bee community traits was best explained by bloom cover. Chapter four further examines the effect of prescribed fire management on plant and bee communities in prairies and wetlands. We found that prescribed burns improved the native plant community, but only in restored prairies. Moreover, bee community response was meditated by functional traits, namely nesting strategy. Finally, chapter five evaluates parasitic infection prevalence by conopid flies and a trypanosome in bumble bees across Southeastern Michigan. This study showed that larger bees generally had higher infection prevalence. Additionally, conopid fly increased with urbanization and decreased with bumble bee abundance. Floral richness was positively associated with bee infection by trypanosomes. Overall, my dissertation research provides insights to inform land management and native bee conservation.