Iron cycling in subalpine wetlands: Impact on fate and transport of dissolved organic carbon

Soils comprise the largest pool of terrestrial carbon (C) and are thus strongly susceptible to climate change, with important implications for greenhouse gas production and surface water quality. Wetlands are especially important players in the global C cycle since they contain about one-third of the planet’s soil C stock. Carbon cycling in soils is partly controlled by their chemistry, especially by the environmental chemistry of iron (Fe), due to the interactions between Fe mineral phases and organic matter. It is consequently crucial to develop a better mechanistic and kinetic understanding of the role that Fe-oxides play in the fate and transport of dissolved organic carbon (DOC) in wetland ecosystems. We are engaged in a multi-scale environmental chemistry study that integrates field-measurements, soil column experiments and molecular measurements to study the influence of climatic parameters, redox conditions, and chemical conditions on the fate and transport of DOC in wetland ecosystems. (Collaboration with T. Borch & E. Kelly, Colorado State University and C. Rhoades,US Forest Service)