Dissertation Research: Drivers of community composition, species interactions, and gene flow in urban landscapes

动物为90%的植物物种授粉；因此，它们对维持健康的生态系统至关重要。在这些动物中，蜜蜂是野生植物最有效和最重要的传粉者之一，它们作为传粉者为农业系统提供的服务每年价值数千亿美元。除了熟悉的驯化欧洲蜜蜂外，世界上还有至少2万种其他种类的野生蜜蜂。然而，由于包括城市化在内的人类造成的景观变化，许多野生蜜蜂的数量正在下降。这项研究探索了城市景观如何改变城市中发现的蜜蜂物种的类型，城市蜜蜂如何利用和授粉本地植物，以及不同大小的蜜蜂物种如何在城市地区迁徙。作为该项目的一部分，研究人员将向土地所有者提出建议，以促进健康的传粉者社区。此外，该项目将通过雇用来自服务不足社区的大学生和高中生作为研究助理来丰富科学界。这项研究将使用网络分析方法来调查城市土地利用模式对植物-传粉者相互作用的影响。跨越城市梯度的植物传粉者网络将通过观察蜜蜂的花卉访问和检查从城市化梯度(40个地点，城市覆盖率从0-100%不等)收集的蜜蜂的花粉多样性来发展。由于之前的观察表明，城市化地区的食物资源比农村地区少，研究人员预测，城市地点的蜜蜂可能会访问更多种类的花卉物种，而农村地点的蜜蜂可能会更专门地选择食物。为了研究城市景观中的扩散和定居模式，这项研究还将检查两个密切相关的木蜂物种的遗传构成。这些物种在筑巢行为上相似，但大小不同，因此它们的扩散潜力也不同。研究人员预测，较大的物种(维吉尼亚木霉)将显示出较少的种群隔离的遗传特征(例如。近亲繁殖)，而不是较小的物种(Ceratina Strenua)，因为它们可以在城市地区传播得更远。最终，这项研究的结果将允许推断传粉者如何随着时间的推移在城市景观中持续存在。

Animals contribute to the pollination of 90% of all plant species; therefore they are essential for maintaining healthy ecosystems. Of these animals, bees are some of the most effective and important pollinators of wild plants and their service as pollinators to agricultural systems is worth hundreds of billions of dollars each year. In addition to the familiar domesticated European honeybee, there are at least 20,000 other species of wild bees worldwide. Many of these wild bee populations, however, are declining in number due to human-caused landscape changes, including urbanization. This research explores how urban landscapes alter the types of bee species found in cities, how urban bees use and pollinate native plants, and how different-sized bee species move through urban areas. As a part of this project, researchers will make recommendations to land owners to promote healthy pollinator communities. In addition, this project will enrich the scientific community by employing college and high school students from underserved communities as research assistants. The study will investigate the impacts of urban land use patterns on plant-pollinator interactions using a network analysis approach. The plant-pollinator networks across an urban gradient will be developed through observations of floral visits by bees and the examination of pollen diversity collected from bees found along a gradient of urbanization (40 sites ranging in urban coverage from 0-100 %). As previous observations indicate that urbanized areas contain fewer food resources than rural areas, the researchers predict that bees at urban sites may visit a greater variety of floral species, whereas bees in rural sites may be more specialized in their food choices. To investigate dispersal and colonization patterns within urban landscapes, this study will also examine the genetic make-up of two closely related carpenter bee species. These species are similar in nesting behavior, but vary in size and thus their dispersal potential. The researchers predict that the larger species (Xylocopa virginica) will show fewer genetic signatures of population isolation (ex. inbreeding) than the smaller species (Ceratina strenua) because they can disperse farther through urban areas. Ultimately, results from this study will allow inferences on how pollinators can persist in urban landscapes over time.