I received a Bachelor's degree in Chemistry from Yale University in 1987 and a Masters (1994) and PhD (1997) in Environmental Sciences from the University of Virginia. I had a post-doctoral position from 1997-1999 at the US Environmental Protection Agency in Corvallis, Oregon, and a second post-doctoral position from 2000-2001 at the Max Planck Institute for Biogeochemistry in Jena, Germany, before joining the Institute.
The main focus of my work has been using stable isotopes at natural abundance levels to understand carbon and nitrogen cycling in forest ecosystems. I am particularly interested in understanding the importance of mycorrhizal fungi in forests and in tundra environments, both as a carbon sink and as a source for nitrogen. Mycorrhizal fungi are ubiquitous root symbionts that supply the majority of nutrients to forest vegetation, protect tree roots against pathogens, and filter out potentially toxic metals such as aluminum. Mycorrhizal fungi appear heavily affected by atmospheric nitrogen deposition in Europe, and we suspect that the same processes are starting to operate in the northeastern US, with possibly deleterious consequences for forest health, including the uptake of other important nutrients such as calcium. We use culture studies, isotopic tracers, natural abundance measurements, and computer modeling to understand the role of mycorrhizal fungi in terrestrial ecosystems.
Other work has included using isotopic measurements to understand diets of small rodents, marsupials, bears, and kiwi, assessing the carbon sources of 400-million-year old fungi (that happened to be 6 meters tall), and applying tracer isotopes of glucose to understand the main metabolic fluxes during lipid biosynthesis in cultured fungi. More information about my past and present research can be found at http://www.isotope.unh.edu/research.shtml.
Ph.D., Environmental Science, University of Virginia
M.S., Environmental Science, University of Virginia
B.S., Chemistry, Yale University
Zhao, L. Z., Colman, A. S., Irvine, R. J., Karlsen, S. R., Olack, G., & Hobbie, E. A. (2019). Isotope ecology detects fine-scale variation in Svalbard reindeer diet: implications for monitoring herbivory in the changing Arctic. Polar Biology, 42(4), 793-805. doi:10.1007/s00300-019-02474-8