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

University Of California-San Diego, La Jolla CA

Investigators

Abstract

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.