DISSERTATION RESEARCH: The effects of pollinator diversity loss on plant-pollinator interaction networks and native plant reproduction in scrub ecosystems of Southern California

人类发展往往导致传粉媒介多样性的下降，但人们对这种下降如何影响自然（如非农业）生态系统中的传粉生态系统服务知之甚少。研究了南加州大型自然保护区的一系列灌丛生境，以及嵌入在城市景观中的小块自然灌丛生境。该研究将研究传粉媒介多样性的下降如何影响传粉媒介与本地植物之间的相互作用以及本地植物物种的繁殖。该项目的研究结果将对自然生态系统中植物-传粉者相互作用的保护、管理和恢复具有重要意义。此外，至少有六名本科生将接受各种实验室和现场技术的培训，以及有关科学职业的指导。该项目的其他更广泛的影响包括让高中生参与动手科学研究，并提供有关南加州本地传粉媒介多样性和分布的数据。本研究将评估传粉媒介多样性与植物-传粉媒介相互作用网络的结构和功能之间的因果关系。本文将利用位于南加州自然保护区和灌丛生境碎片的经验花访花观测资料构建传粉网络。此外，还将通过实验将一种本地植物引入研究地点，以评估传粉网络重组对植物传粉和繁殖的潜在影响。本文将验证两种假设：(1)传粉媒介多样性丧失产生的网络比基于现存传粉媒介分类群数量的预期具有更高的模块化和更少的链接；(2)与传粉媒介多样性丧失相关的网络结构变化对焦点本地植物物种的花访问、花粉沉积和整体生殖适合度产生负面影响。

Human development often causes declines in the diversity of pollinators, but little is known about how such declines impact pollination ecosystem services in natural (e.g., non-agricultural) ecosystems. For a series of scrub habitat field in large natural reserves and in small patches of natural scrub habitat embedded in urban landscapes sites in Southern California. The research will examine how declines in pollinator diversity impact interactions between pollinators and native plants and the reproduction of a native plant species. The findings of this project will be relevant to the conservation, management, and restoration of plant-pollinator interactions in natural ecosystems. Additionally, at least six undergraduate students will receive training in a diversity of laboratory and field techniques as well as mentorship regarding careers in science. Additional broader impacts of this project include engaging high school students in hands-on scientific research and contributing data on the diversity and distribution of Southern California native pollinators.The research will evaluate the causal link between pollinator diversity and the structure and function of plant-pollinator interaction networks. Pollination networks will be constructed using empirical floral visitation observations study sites located in natural reserves and scrub habitat fragments in Southern California. A native plant species will also be experimentally introduced into study sites to evaluate how the restructuring of pollination networks may potentially impact plant pollination and reproduction. Two hypotheses will be tested: (1) pollinator diversity loss yields networks with higher modularity and fewer links than expected based on the number of extant pollinator taxa, and (2) changes in network architecture associated with pollinator diversity loss negatively affect floral visitation, pollen deposition, and overall reproductive fitness of a focal native plant species.