DISSERTATION RESEARCH: Effects of experimental shifts in soil moisture and flowering phenology on plant-pollinator interactions

University Of California-Irvine, Irvine CA

Investigators

Abstract

Most flowering plants and many of the world's food crops depend on animal pollinators to reproduce. Recent changes in climate may disrupt these ecologically and economically important relationships. Warm springs and early snowmelt associated with climate change alter when plants flower and pollinators emerge in the spring, which may make pollinators unavailable to plants that flower too soon or too late. In addition, decreased snow cover and early snowmelt likely reduce soil moisture during the growing season on mountain slopes. Such drought conditions may decrease the number of flowers, their size or the amount of nectar they contain, which may make them less attractive to pollinators. This research tests effects of soil moisture and timing of flower and pollinator emergence on pollination. The expectation is that drought will greatly decrease pollination through both changes in flowering time and attractiveness. This work will help reveal how the relationship between plants and pollinators responds to climate change, and will improve the ability of land-managers and policy-makers to plan conservation efforts. This project also includes opportunities to engage undergraduate students and public school teachers in field research, as well as providing gateway experiences for children into science through two K-12 outreach programs. This project tests the hypothesis that differences in flowering time interact with water availability to affect the composition and number of pollinator visits. Using field-tested methods, researchers will manipulate flowering time and soil moisture in a factorial experiment with the sub-alpine wildflower Mertensia ciliata. They will measure the impact on pollination and seed set via shifts in the composition and number of pollinator visits, and will determine how those effects may be mediated by changes in floral traits. Experimental results will be integrated with on-going observational studies of individual, population, and community-level responses to natural variation in soil moisture and flowering phenology. Similar field experiments testing the impacts of abiotic and biotic shifts on plant-pollinator interactions are rare. Yet, such experimental approaches can offer vital insights into the mechanisms that determine how pollination systems respond to climate change. All analyzed data under this award will be disseminated at professional conferences, published in peer-reviewed journals, and made publically available.