Opportunities

Ph.D. position studying methane oxidation around the roots of wetland plants

The Neumann lab at the University of Washington in Seattle has an opening for a Ph.D. student to work on a project investigating methane oxidation in the soil zone surrounding roots of wetland plants and assessing how this process will change under future climate conditions. The project will involve multiple years of fieldwork in Alaska and laboratory investigations of field-collected samples. The hired person will have the opportunity to interface with a Ph.D. student funded by the same project who will be modeling wetland methane emissions, and with other researchers who are experts in methane biogeochemistry and plant ecophysiology. The Neumann lab is well connected with faculty within the UW Civil & Environmental Engineering department, UW School of Environmental and Forest Sciences, and at the Alaskan field site. If you are interested, please apply to the CEE department for admission to the PhD program. (see http://www.ce.washington.edu/prospective/grads/index.html for the application process). Be sure to mention your interest in this project in your application.

Project Overview

Methane is a potent greenhouse gas, with a global warming potential 20-times larger than that of carbon dioxide. The objective of the planned research project is to improve predictions of future methane emissions. The project will achieve its objective by examining the conversion of methane to carbon dioxide (i.e., methane oxidation) within the soil zone surrounding roots (the rhizosphere) of wetland plants. Wetlands are the largest natural source of methane to the atmosphere, and a majority of methane emitted by wetlands travels from soil through plants to the atmosphere. Plants also support the movement of atmospheric oxygen into the soil where it can oxidize methane; up to 90% of the methane produced in wetlands can be converted to carbon dioxide in this way. However, the process is not well captured by most computer models where oxidation of methane is simply set to a constant percentage. In reality, the percentage of methane oxidized in the rhizosphere is dynamic, responding to soil and water chemistry and to plant traits and behavior. As the climate changes, plant species composition, plant behavior, and subsurface chemistry will change, altering the fraction of methane oxidized within wetlands. Thus, understanding the dynamic response of methane oxidation to these expected climate-induced changes is key to accurately predicting future methane emissions.

he planned project will study the potential for future changes in methane oxidation using a combination of field measurements, laboratory experiments and modeling investigations informed by field and laboratory results. Currently, we are looking for a PhD student interested in conducting the fieldwork and laboratory experiments.

Fieldwork: The chosen field sites for this project include a rich fen and ombrotrophic bog outside of Fairbanks, Alaska. The sites are part of the Bonanza Creek long-term ecological research program (http://www.lter.uaf.edu/). The project will involve three summers of fieldwork at these sites.

Lab Experiments: The planned experiments involve working with soil and vegetation collected from the field site and shipped to our laboratory. At the core of the experiments is the use of planar oxygen sensors (optodes) to visualize oxygen concentrations around the roots of the collected plants. The oxygen data will be used to direct sampling of porewater and soil, as well as inform experimental manipulations conducted on the collected material.