Hydrologic control of carbon cycling and aged carbon discharge in the Congo River basin
Eglinton, Timothy I.
Spencer-Jones, Charlotte L.
De Pol-Holz, Ricardo
Talbot, Helen M.
Grootes, Pieter M.
Schneider, Ralph R.
MetadataShow full item record
The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. While elevated ages in fluvially-transported organic matter are usually explained by erosion of soils and sediments deposits it is commonly assumed that mainly young organic material is discharged from flat tropical watersheds due to their extensive plant cover and rapid carbon turnover. Here we present compound-specific radiocarbon data of terrigenous organic fractions from a sedimentary archive offshore the Congo River in conjunction with molecular markers for methane-producing land cover reflecting wetland extent. We find that the Congo River has been discharging aged organic matter for several thousand years with apparently increasing ages from the Mid- to the Late Holocene. This suggests that aged organic matter in modern samples is concealed by radiocarbon from atmospheric nuclear weapons testing. By comparison to indicators for past rainfall changes we detect a systematic control of organic matter sequestration and release by continental hydrology mediating temporary carbon storage in wetlands. As aridification also leads to exposure and rapid remineralization of large amounts of previously stored labile organic matter we infer that this process may cause a profound direct climate feedback currently underestimated in carbon cycle assessments.
Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Geoscience 9 (2016): 687-690, doi:10.1038/ngeo2778.
Suggested CitationPreprint: Schefuß, Enno, Eglinton, Timothy I., Spencer-Jones, Charlotte L., Rullkötter, Jürgen, De Pol-Holz, Ricardo, Talbot, Helen M., Grootes, Pieter M., Schneider, Ralph R., "Hydrologic control of carbon cycling and aged carbon discharge in the Congo River basin", 2016-07, https://doi.org/10.1038/ngeo2778, https://hdl.handle.net/1912/8465
Showing items related by title, author, creator and subject.
Lake Michigan water chemistry data, including dissolved and particulate phosphorus, chlorophyll a, carbon dioxide, total dissolved inorganic carbon, and dissolved organic carbon. Bootsma, Harvey; Liao, Qian (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2019-03-15)Lake Michigan water chemistry data, including dissolved and particulate phosphorus, chlorophyll a, carbon dioxide, total dissolved inorganic carbon, and dissolved organic carbon. For a complete list of measurements, refer ...
Consequences of considering carbon–nitrogen interactions on the feedbacks between climate and the terrestrial carbon cycle Sokolov, Andrei P.; Kicklighter, David W.; Melillo, Jerry M.; Felzer, Benjamin S.; Schlosser, C. Adam; Cronin, Timothy W. (American Meteorological Society, 2008-08-01)The impact of carbon–nitrogen dynamics in terrestrial ecosystems on the interaction between the carbon cycle and climate is studied using an earth system model of intermediate complexity, the MIT Integrated Global Systems ...
Allochthonous sources and dynamic cycling of ocean dissolved organic carbon revealed by carbon isotopes Zigah, Prosper; McNichol, Ann P.; Xu, Li; Johnson, Carl G.; Santinelli, Chiara; Karl, David M.; Repeta, Daniel J. (John Wiley & Sons, 2017-03-07)We present concentration and isotopic profiles of total, size, and polarity fractionated dissolved organic carbon (DOC) from Station ALOHA (A Long-term Oligotrophic Habitat Assessment), an oligotrophic site in the North ...