The main objective of my CAREER plan is to improve our understanding of feedbacks between peatland ecosystems and the atmosphere in response to global climate change and increasing atmospheric nitrogen (N) deposition through a combination of research and educational activities with undergraduate women students at Mount Holyoke College and collaborations with peatland scientists in Canada, U.S. and Finland. Peatlands contain one-third of the global pool of soil carbon, which is currently sequestered as peat under cold, waterlogged conditions. However, if the climate becomes warmer and drier in the northern latitudes, soil decomposition rates could increase, adding more carbon dioxide (CO2) and methane (CH4) to the atmosphere, thus fueling the warming trend. Alternatively, plant growth could be enhanced under a warmer, drier climate, thus removing more CO2 from the atmosphere through enhanced photosynthesis. Elevated levels of atmospheric nitrogen could also stimulate plant growth. In sum, peatlands will either become positive or negative feedbacks to global warming depending on the relative responses of plant growth and soil decomposition to climate change and N deposition. I propose a cascade mentoring approach where students evolve from research assistants to full collaborators in furthering our understanding of three main topics: (1) the environmental controls on interannual and seasonal variability in carbon dioxide and methane exchange, important greenhouse gases, (2) the different responses of a range of plant communities along hydrologic and nutrient gradients to climate variability, and (3) the influence of nitrogen deposition on the carbon balance and vegetation community composition.
