Date of Award
Master of Science (MS)
Anthropogenic climate change is driving major shifts in global temperatures and increases in extreme temperature events that contribute to reduced survival and species loss. To counteract extreme temperatures, many organisms can undergo geographic range shifts or engage in behavioral thermoregulation (e.g., movement to suitable microhabitats). While plants are sessile and thus subject to highly variable ambient temperatures, they have evolved mechanisms to regulate internal floral temperature. Floral thermoregulation may mitigate thermal stress on pollen and ovules and impact plant-pollinator interactions. These mechanisms for thermoregulation are often highly dependent on ambient temperature and solar radiation as most plants are not endothermic. Argentina anserina is a small perennial herb with a wide distribution spanning latitudinal and elevational gradients. I developed artificial flowers to mimic A. anserina that differentially absorbed infrared light to alter floral temperature without influencing other signals perceived by pollinators. I used these artificial flowers to investigate how floral reflectance properties interact with environmental factors to modify internal floral temperature across a 1000m elevation gradient and assess the impacts of floral temperature on pollinator visitation and behavior. Finally, I used a greenhouse experiment to test how petal angle and infrared reflectance interact with solar irradiance to influence internal floral temperatures. Together, my work has implications for how flowering plants may respond to extreme temperatures, and how floral temperature could impact plant reproduction through its effects on insect pollination.
Apland, Jennifer, "The Floral Thermal Environment: Physical, Morphological, and Environmental determinants, and their impact on Plant-Pollinator Interactions" (2023). All Theses. 4171.