Graduate Research Assistant Project title: Modeling the Temperature Sensitivity of Plant Respiration University of Florida, Gainesville, Department of Biology
Supervisors: Jeremy Lichstein (http://biology.ufl.edu/People/faculty/jlichstein.aspx), Kaoru Kitajima (http://www.biology.ufl.edu/People/faculty/kitajima.aspx), and Stefan Gerber (http://soils.ifas.ufl.edu/personnel/gerber.html) Plant respiration consumes roughly half of gross primary productivity and is expected to increase with climate warming. In the tropics in particular, plant respiration rates are expected to increase relative to photosynthetic rates as the climate warms. The resulting decrease in tropical net primary productivity (NPP) could threaten the sustainability of current terrestrial carbon sinks, resulting in a positive feedback to climate change. Alternatively, temperature acclimation of respiration could minimize future temperature-induced NPP declines. This project will use a state-of-the-art ecosystem process model to quantify the impact of climate change on terrestrial carbon balance, with particular emphasis on the temperature sensitivity and acclimation of plant respiration. The project will leverage multiple data sources, including an ongoing NSF- funded study on the temperature response of tropical trees to experimental warming. The NSF study involves in-situ measurements of leaf and branch respiration using a canopy crane in central Panama, as well as experiments with tropical tree seedlings (for more details, see http://people.biology.ufl.edu/jlichstein/respiration_summary.pdf). These and other data sources are providing improved information on the temperature sensitivity and acclimation of plant respiration at scales ranging from leaves to whole plants. However, our understanding of the ecosystem-to global-scale implications of these fine-scale processes remains primitive. The successful candidate will use a process-oriented ecosystem model to “scale up” leaf- and plant-level measurements to whole ecosystems. Candidate models include the Ecosystem Demography (ED) model (Moorcroft et al. 2001, Ecol. Monog. 71:557-586; Medvigy et al. 2009, J. Geophys. Res. 114:G01002) and the NOAA-GFDL LM3V land model (Shevliakova et al. 2009, Global Biogeochem. Cy. 23:GB2022; Gerber et al. 2010, Global Biogeochem. Cy. 24:GB1001). In support of the NSF-funded project described above, the modeling work will include applications focused on central Panama. In addition, there is considerable freedom to develop complementary aspects of the research program, which could (for example) extend this work to broader spatial scales. Qualifications: Undergraduate degree in biology, environmental science, applied mathematics, computer science, or related field. Funding: 2.5 years of Research Assistant support are available, including summer support and funds for independent field work. Additional funding is available through UF Department of Biology Teaching Assistantships and external funding sources. Start date: Fall semester (August) 2012. Application instructions: Submit an application to the UF Department of Biology graduate program (deadline December 15, 2011): http://www.biology.ufl.edu/Graduate/Application.aspx. Minorities, women and members of other underrepresented groups are encouraged to apply. The University of Florida is an equal opportunity institution.
