Dissolved Organic Carbon Fluxes in Rivers of the Conterminous United States: Influence of Terrestrial - Aquatic Linkages

Management of terrestrial carbon stocks in natural ecosystems has been proposed as a sustainable approach to counteracting the anthropogenic contribution of carbon dioxide to the atmosphere. One factor of uncertainty in carbon accounting is that a portion of carbon assumed to be sequestered in soils may in fact be transported to river networks. The primary objectives of this study are to: 1) determine if the magnitude of empirical estimates of dissolved organic carbon (DOC) export in rivers correlates with simulated soil DOC leachate values from terrestrial carbon models, and 2) quantify terrestrial loading of DOC to river networks across the conterminous US. We evaluated the magnitude of riverine DOC fluxes relative to carbon storage in terrestrial biomass and soils using the aggregated results from the terrestrial carbon models included in the LandCarbon and Multi-scale Synthesis and Terrestrial Model Intercomparison Projects. We also compared gridded terrestrial DOC leaching values to downstream DOC fluxes in rivers estimated by the USGS LOADEST model. Quantification of terrestrial-aquatic linkages is necessary to better evaluate ecosystem carbon sequestration as a potential tool for mitigating anthropogenic perturbance to the global carbon cycle.