Arctic temperatures in the coming decades are projected to dramatically increase due to human induced increases in greenhouse gases. This change in temperature will also warm the soil, accelerating microbial decomposition of soil organic matter and increasing soil carbon (C) release to the atmosphere in the form of carbon dioxide and methane. Concurrent to this release of soil C there is expected to be a warming induced increase in arctic plant growth. The tradeoff between soil decomposition and plant growth is extremely complex: plant growth sequesters carbon dioxide from the atmosphere but is severely limited by the low availability of nitrogen (N) in high latitude soils.  As a result, increased plant sequestration of C will only occur if available N also increases with temperature. Increased storage of atmospheric C in plants will be necessary to counterbalance the release of C from decomposing soils under warmed conditions. My research focuses on how plant available N changes as a tundra ecosystem is exposed to warmer temperatures. I work within the CiPEHR manipulative warming experiment located just north of Denali National Park. This experiment warms plants and soils by just a few degrees but has already increased the depth of permafrost thaw, inorganic N availability in surface soils, and growing season exchange of CO2. By investigating links between C and N cycling in thawing arctic ecosystems I hope to improve our understanding of how natural ecosystems will respond to climate change.

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