UC Riverside

Anthropogenic global climate change can disrupt plant-pollinator interactions by altering the traits, phenologies, and distributions of interacting species, exacerbating insect declines and compromising ecosystem function. However, most research has focused on diurnal pollinators, and little is known about the prevalence, importance, and vulnerability of nocturnal moth pollination. This knowledge gap limits our ability to predict and mitigate the effects of climate change and other stressors on moths and their pollination services. In this dissertation, I investigate the ecology of moth pollination interactions, how moths and their host and nectar plants will be impacted by climate change, and how to apply this knowledge in conservation strategies. I focus on native plants and moths in California, a biodiversity hotspot that is particularly impacted by climate change. I employ techniques ranging from greenhouse experiments to DNA metabarcoding to explore impacts spanning the levels of functional traits to ecological networks. In Chapter 1, I document hundreds of previously undescribed moth pollen-transport interactions along an elevational gradient spanning desert to conifer forest. I also find that moths are smaller, less diverse, and more sensitive to the simulated loss of their nectar plants in hotter and drier conditions. In Chapter 2, I reveal that experimental warming and drought alter diel patterns of floral nectar quantity and quality in a generalist plant. This may differentially affect interactions with diurnal and nocturnal pollinators, scaling up to alter the structure and stability of plant-pollinator interaction networks. In Chapter 3, I analyze and compare Lepidoptera-host and -nectar plant interaction networks across California, revealing structural differences and spatial patterns that inform management priorities. I also analyze species roles in networks to identify spatially-explicit keystone plant species to be used in butterfly and moth conservation efforts. Together, my results reveal that moth pollination interactions are diverse, complex, and vulnerable to climate change, and that data-driven conservation strategies can help protect them. Ultimately, this dissertation highlights the importance of considering the nocturnal components of plant-pollinator networks in research and management.