DISSERTATION RESEARCH: Plant-microbe effects on soil carbon storage in a changing global environment

Our planet's environment is changing. Since the Industrial Revolution, land use change, fertilizer use, and fossil fuel combustion have increased atmospheric carbon dioxide concentrations by 40% and nitrogen inputs twelve fold. Plants and soils could either mitigate or accelerate this global change because of their role in taking up and cycling carbon and nutrients. This research addresses how one key player in plant-soil systems affects carbon storage and release. Fungi in soil connect to plant roots and transfer nutrients from the soil to the plant in exchange for carbon from the plant. However, it is unclear whether these fungi will facilitate net retention or release of carbon in the soil. On the one hand, fungi could protect carbon in soil under elevated CO2 concentrations. It is also possible that soil fungi have the opposite effect, and accelerate decomposition of carbon. This doctoral dissertation improvement grant project will test the extent to which each of these scenarios is accurate. Experiments will take place at Cedar Creek Ecosystem Science Reserve in Minnesota where the Ph.D. student has conducted her main dissertation research. Results from this research, combined with the student's ongoing work, will inform how total soil carbon storage might be affected by soil fungi in a changing global environment.

This research will not only advance understanding of global change effects on C cycling but will also provide unique educational opportunities. This award will greatly enhance the Ph.D. student's graduate training through collaboration in stable isotope analysis - a novel tool for studying flow of C through ecosystems - which would not be possible otherwise. Through performing the proposed work in collaboration with Dr. Elise Pendall (University of Western Sydney), who has significant experience with stable isotope analysis, the student will develop a strong skill set, building off her participation in the NSF-funded Stable Isotope Biogeochemistry and Ecology course at the University of Utah. Developing skills in using stable isotopes in ecological research could also generally increase the value she would bring to future collaborations. Additionally, the graduate student will leverage her ongoing leadership with the Boreas Environmental Leadership Program at the University of Minnesota's Institute on the Environment to explore new professional development opportunities for graduate students in the sciences to discuss and practice sharing their research to non-academic audiences.