15. Improving Vegetation Model Simulations of Future Climate Change Effects on Public Lands in the United States
Numerous research efforts are currently focused on understanding how ecological systems will respond to future climate changes. How will climate change affect the distributions of species? Will climate change alter the frequency and magnitude of important ecosystem disturbances such as wildfires and droughts? Physically-based vegetation models are frequently used in global change research to try and answer these and other questions. Vegetation models are used to explore the temporal and spatial dynamics of ecosystem responses to climate change, test hypotheses about ecosystem response, and forecast potential future ecosystem changes. Although many vegetation models are physically complex they still oversimplify important ecosystem processes and require improvement to more accurately simulate ecosystem responses to climate change. Of particular concern is the inability of many models to simulate ecosystem responses at the high spatial and temporal resolutions required by conservation and natural resource managers for developing management responses to potential climate change impacts on public lands.
The goal of this postdoctoral research opportunity is to improve vegetation model simulations of the physical processes that control ecosystem responses to climate change and the usefulness of these simulations for conservation and natural resource management. The proposed research will focus on two vegetation models: LPJ (Lund-Potsdam-Jena; Sitch and others, 2003), a dynamic global vegetation model (DGVM), and GUESS (Smith and others, 2001), a general ecosystem model. These models are used by the EFFECTS (Exploring Future Flora, Environments, and Climates Through Simulations) Project and the CLUES (Climate Change, Land Use, and Environmental Sensitivity) Project at the USGS to simulate both paleo and future ecosystem responses to climate change.
The postdoctoral researcher may propose research involving any of the different ecosystem processes simulated by the vegetation models, as appropriate, given the researcher’s background and expertise. Model processes that are particularly relevant to current USGS research include:
- Species distributions: Ex. Refining and adding new model definitions of species and plant functional types to assess the sensitivity of the distributions of important species and habitat types to future climate change;
- Disturbance regimes: Ex. Simulating potential changes in the magnitude and frequency of wildfire, drought, or insect outbreak events under future climate conditions;
- Hydrologic cycle: Ex. Improving parameterizations and submodels of soil hydrology, snow accumulation, or permafrost dynamics relative to observed data in order to increase our understanding and confidence in model simulations for future time periods.
Improving the ability of vegetation models to function at higher spatial and temporal resolutions is fundamental to improving their relevance to conservation and natural resource management activities. Thus, a key requirement of the postdoctoral researcher’s proposed research is that it be scalable, improving the ability of the vegetation models to simulate ecosystem processes at fine spatial (~1 km) and temporal (daily) resolutions as well as at coarser scales.
The postdoctoral researcher will design the vegetation model improvements, write and revise model code to implement the changes, evaluate the new model simulations for improved accuracy, apply the improved models to the researcher’s particular research question(s), and publish their research results demonstrating the ways in which the revised models improve our understanding of ecosystem responses to climate change. The postdoctoral researcher will work closely with USGS scientists and their colleagues. Full access to state-of-the-art global and regional climate model simulations for past, present, and future climates will be available as will the opportunity to work with Hostetler’s regional climate modeling project.
The postdoctoral researcher will also confer with conservation and natural resource managers to incorporate the information needs of managers into their research design. It is expected that land managers will be able to provide guidance in a number of ways, including on the temporal and spatial scales of analysis most relevant to the management of particular ecosystems, by identifying ecosystems or processes for which information on climate change impacts is needed, and by suggesting additional variables that the vegetation models could simulate that would be of particular use for developing management responses to climate change.
Research proposals should describe in detail how the work will lead to improvements in 1) vegetation model simulations of the physical processes that control ecosystem responses to climate change and 2) the usefulness of vegetation model simulations for conservation and natural resource management activities. This position requires 1) demonstrated experience working with vegetation models, 2) computer programming skills (e.g., FORTRAN90, C++) necessary to revise, expand and run model codes, and 3) the ability to evaluate model simulations quantitatively and graphically. Previous experience working on conservation and natural resource issues is also desirable. The successful candidate will be expected to publish and communicate research results to a diverse audience of scientists, conservation and natural resource managers, and the general public.
References
Sitch, S., Smith, B., Prentice, I. C., Arneth, A., Bondeau, A., Cramer, W., Kaplan, J. O., Levis, S., Lucht, W., Sykes, M. T., Thonicke, K., and Venevsky, S., 2003, Evaluation of ecosystem dynamics, plant geography and terrestrial carbon cycling in the LPJ dynamic global vegetation model: Global Change Biology, v. 9, p. 161–185. Smith, B., Prentice, I. C., and Sykes, M. T., 2001, Representation of vegetation dynamics in the modeling of terrestrial ecosystems: comparing two contrasting approaches within European climate space: Global Ecology and Biogeography, v. 10, p. 621–637.Proposed Duty Station: Corvallis, OR
Areas of Ph.D.: Earth system science/modeling, ecology, geography, geology, hydrology, or related discipline
Qualifications: Applicants must meet one of the following qualifications: Research Ecologist , Research Geographer, Research Geologist, Research Hydrologist, Research Physical Scientist
(This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)
Research Advisor(s): Sarah Shafer, (541) 750-7412, sshafer@usgs.gov ; Steve Hostetler, (541) 737-8928, swhostet@usgs.gov
Human Resources Office contact: Candace Azevedo, (916) 278-9393, caazevedo@usgs.gov
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Summary of Opportunities |