Floral Abundance and Soil Characteristics Affect Wild Bee Community Structures and Nesting Dynamics in Tallgrass Prairies By

Tallgrass prairies have been reduced to less than 5% of their former range, yet provide essential habitats for many native plants and animals such as pollinators. Land managers work to preserve the biodiversity within these tallgrass prairies by implementing management techniques such as burning, haying, and patch-burn-grazing (PBG). All treatments utilize burning, but haying removes aboveground biomass and PBG includes grazing by cattle. The impacts of these management practices on important ecological factors for bee species, such as floral community structure and nesting resources are examined in this study. Floral resources and bee communities are usually positively correlated within ecosystems due to their mutualistic interactions. The interactions between flowers and bees are important in maintaining the sustainability of many ecosystems including managed prairies. In Chapter 1, I investigate how management alters the abundance, richness, diversity, and composition of both plant and bee communities and whether there are differences in the interactions between bee species and the plants they forage on within 20 different prairie sites in Missouri. Analyses were conducted for the four treatments and by collapsing the treatments into two groups, grazed and ungrazed. I discovered that floral abundance in ungrazed sites is higher than on sites that support cattle. However, the bee communities that utilize prairie ecosystems do not change based on management techniques. This may be due to the resilience of the bee species that occur in Missouri compared to the species that occurred in Missouri before the landscape was fragmented. Species remaining in the highly disturbed prairie fragments may be less specialized and better adapted at persisting despite the difference in management. Despite there being no difference in bee communities in grazed and ungrazed patches, the interaction networks between bee species and their host plants are more complex in the prairies without cattle and more iii competitive in the prairies with cattle. Additionally, out of the 1769 bees included in my study, only two were honey bees. Therefore, I found no evidence that honey bees are displacing native bees in prairie ecosystems. Soil characteristics could also affect bee community structure and nesting rates on prairies because most bees nest underground for the majority of their lives. In Chapter 2, I investigate the soil characteristics within the four management treatments including temperature, moisture, pH, bulk density, composition, and bare ground ranks and compare the measurements to ground-nesting bee nesting rates. I used emergence tents to collect ground-nesting …