Transport of dissolved organic matter by river networks from mountains to the sea: a re-examination of the role of flow across temporal and spatial scales

The transport of dissolved organic matter (DOM) by rivers is an important component of the global carbon cycle, affects ecosystems and water quality, and reflects biogeochemical and hydrological processes in watersheds. Understanding the fundamental relationships between discharge and DOM concentration and composition reveals important information about watershed flow paths, soil flushing, connectivity to riparian zones, organic matter leaching, soil moisture, and climatic influences. Data to describe these processes - both magnitude and timing - is critical for modeling and predicting watershed DOM dynamics, particularly in light of land use and climate change . Despite several decades of data collection, a synthesis of how hydrology drives DOM dynamics and what this tells us about watershed sources and processes remains elusive. We propose to bring together a multi-disciplinary team to re-evaluate the fundamental relationships between stream discharge and DOM concentration and composition. Our effort will focus on synthesizing mature data sets from small headwater basins to large coastal basins using statistical techniques and modeling, and will include both the quantity (concentration and loads) and quality of DOM. Participants will contribute datasets spanning a range of temporal sampling intensities from quarterly to weekly, to those including intensive sampling from automated samplers during high flow events, and finally to continuous data sets from optical sensors. We expect that the synthesis of these data will facilitate new and unprecedented insights into trends in DOM across space and time and result in improved understanding of organic matter dynamics in aquatic ecosystems.



Publications:

Creed, I.F., McKnight, D.M., Pellerin, B.A., Green, M.B., Bergamaschi, B.A., Aiken, G.R., Burns, D.A., Findlay, S.E.G., Shanley, J.B., Striegl, R.G., Aulenbach, B.T., Clow, D.W., Laudon, H., McGlynn, B.L., McGuire, K.J., Smith, R.A., and Stackpoole, S.M., (2015). The river as a chemostat: fresh perspectives on dissolved organic matter flowing down the river continuum. Canadian Journal of Fisheries and Aquatic Sciences 72. doi:10.1139/cjfas-2014-0400

Stackpoole, S. M., Stets, E. G., Clow, D. W., Burns, D. A., Aiken, G. R., Aulenbach, B. T., Creed, I. F., Hirsch, R. M., Laudon, H., Pellerin, B. A., and Striegl, R. G. (2016) Spatial and temporal patterns of dissolved organic matter quantity and quality in the Mississippi River Basin, 1997-2013. Hydrol. Process., doi: 10.1002/hyp.11072.

Stackpoole, S.M., Stets, E.G., Striegl, R.G. (2014). The impact of climate and reservoirs on longitudinal carbon fluxes from two major watersheds in the Central and Intermontane West. Journal of Geophysical Research - Biogeosciences. doi: 10.1002/2013JG002496