This action funds an NSF Minority Postdoctoral Research Fellowship for FY 2010. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Jessica L. Osuna is "A physiological study of the progression from drought stress to mortality in piñon pine." There are two host institutions for this research, the University of New Mexico and the Los Alamos National Laboratory, and joint sponsors, William T. Pockman and Nate G. McDowell.
Recent warm droughts have caused very high piñon pine mortality rates in the Southwestern USA. A complete understanding of the underlying mechanisms of this mortality would allow accurate prediction of its occurrence in other regions, species, and periods of time. This research investigates the autotrophic carbon budget via measurements of photosynthesis, respiration, non-structural carbohydrate levels, and resin flow under varying levels of drought stress to test whether carbon starvation is responsible for drought-induced piñon mortality. Carbon starvation occurs if a prolonged decrease in stomatal conductance leads to reduced photosynthetic carbon fixation, causing the depletion of carbohydrate pools by maintenance respiration which continues through a drought.
Because piñons provide vital ecosystem services such as reducing floods and erosion,sequestering carbon dioxide, and providing habitat for wildlife and culturally significant plants, the ability to proactively adopt management strategies that could reduce mortality, or the effects thereof, is vital to the region and has a significant broader impact. The research crosses disciplinary boundaries by forming links between climatologists, ecophysiologists, and plant physiologists. Training objectives include learning to use the novel tunable diode laser to measure carbon isotope discrimination simultaneously with gas-exchange as well as techniques used for measuring aspects of the carbon budget other than photosynthetic fluxes. Finally, educational outreach is being conducted to promote diversity within biology through mentorship of younger minority scientists and by guest lecturing in undergraduate and graduate courses, thus exposing students to diversity in academia.
