Abstract:
The importance of pollinators in native and managed landscapes is well known, and recent interest is directed towards investigating the role of native bees as providers of pollination ecosystem services. Uncertainty about bee populations at global and local scales has prompted research and general interest in conservation of bee diversity. To sustain robust populations, bees need nesting habitat and quality forage resources. This thesis describes two studies related to the relationship between bee diversity and landscape floral resource availability in two Willamette Valley ecosystems: wet prairies and blueberry agroecosystems. The wetlands are florally diverse, heterogeneous, and temporally patchy in spring and summer, whereas blueberries are florally abundant during spring crop bloom with potentially fewer floral resources after berry set; the intention of these studies was to determine if the floral resources in each ecosystem were adequate to support robust native bee communities. For each site type, the bee fauna and associated melittophilous floral resources are described and characterized. In the studies, it was determined that bee diversity, and specifically bee abundance, was positively correlated with floral resources. This thesis presents the results of community analyses, floral resources that were identified as important forage sources, and a discussion of the relationship between landscape phenology and bee population dynamics in each ecosystem type. Implications and recommendations for landscape management to conserve and potentially enhance local native bee communities are discussed.
