This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2020, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. Trees are largely composed of an intricate system of water conducting cells (i.e., wood) that create a continuous pathway for water movement through the plant. With increasing temperature and drought, these plant vascular systems will bear the brunt of increasing stress. As a result, failure of the water transport system (hydraulic failure) will be a dominant mechanism of tree mortality under these circumstances. This is especially true for large trees which make up roughly half of mature forest biomass and contribute significantly to global ecosystem processes. This research examines the ability of large trees to change their hydraulic systems to cope with warming conditions by using trees exposed to the elevated temperatures in urban environments (known as the Urban Heat Island Effect) as a "natural experiment". This work will reveal the risk of future climate-induced tree mortality and identify potential opportunities for mitigating that risk. The fellowship training objectives build on the Fellow?s experience to create a research and teaching program at a primarily undergraduate institution that will further research opportunities for diverse undergraduate communities.
The physiological processes underlying drought-induced tree mortality are far from being fully understood. The key research objective of this fellowship is to bring a unique approach to examine hydraulic trait plasticity of large trees to climate warming. The research will address two interrelated questions: 1) How do hydraulic traits of mature, large trees shift in response to warming? 2) Are these shifts capable of mitigating tree mortality risk under future warming? This research will characterize key xylem hydraulic traits in western US tree species, across an urban heat island gradient in Portland, Oregon. Xylem vulnerability curves will be used to estimate drought resistance traits. This approach will provide more accurate estimates of plant hydraulic traits that represent the ?missing link? between environmental cues and plant responses to drought conditions. The training objectives will also focus on 1) enhancing scientific communication to diverse, non-academic audiences, and 2) creating unique research opportunities for underrepresented minority undergraduate and pre-college students through establishing a near-peer, relational mentorship model to advance the postdoctoral training experience.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
