气候变化领域集成服务门户(CCPortal): The fate of fluvially-deposited organic carbon during transient floodplain storage

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DOI	10.1016/j.epsl.2021.116822
	The fate of fluvially-deposited organic carbon during transient floodplain storage
	Scheingross J.S.; Repasch M.N.; Hovius N.; Sachse D.; Lupker M.; Fuchs M.; Halevy I.; Gröcke D.R.; Golombek N.Y.; Haghipour N.; Eglinton T.I.; Orfeo O.; Schleicher A.M.
发表日期	2021
ISSN	0012821X
卷号	561
英文摘要	CO2 release from particulate organic carbon (POC) oxidation during fluvial transit can influence climate over a range of timescales. Identifying the mechanistic controls on such carbon fluxes requires determining where POC oxidation occurs in river systems. While field data show POC oxidation and replacement moving downstream in lowland rivers, flume studies show that oxidation during active fluvial transport is limited. This suggests that most fluvial POC oxidation occurs during transient floodplain storage, but this idea has yet to be tested. Here, we isolate the influence of floodplain storage time on POC oxidation by exploiting a chronosequence of floodplain deposits above the modern groundwater table in the Rio Bermejo, Argentina. Measurements from 15 floodplain cores with depositional ages from 1 y to 20 ky show a progressive POC concentration decrease and 13C-enrichment with increasing time spent in floodplain storage. These results from the Rio Bermejo indicate that over 80% of fluvially-deposited POC can be oxidized over millennial timescales in aerated floodplains. Furthermore, POC in the oldest floodplain cores is more 14C-enriched than expected based on the independently-dated floodplain ages, indicating that a portion of this oxidized POC is replaced by autochthonous POC produced primarily by floodplain vegetation. We suggest floodplain storage timescales control the extent of oxidation of fluvially-deposited POC, and may play a prominent role in determining if rivers are significant atmospheric CO2 sources. © 2021 Elsevier B.V.
关键词	carbon cycle floodplains organic carbon oxidation rivers
英文关键词	Banks (bodies of water); Carbon dioxide; Digital storage; Floods; Groundwater; Organic carbon; Oxidation; Carbon fluxes; Chronosequences; Floodplain deposits; Fluvial transport; Ground water table; Lowland rivers; Particulate organic carbon; River systems; Rivers; carbon flux; carbon storage; floodplain; fluvial deposit; organic carbon; oxidation; river system; transient flow; Argentina
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203285
作者单位	GFZ-German Research Centre for Geosciences, Potsdam, Germany; Department of Geological Sciences and Engineering, University of Nevada Reno, United States; Institute of Geosciences, University of Potsdam, Germany; Geological Institute, ETH Zürich, Zürich, Switzerland; Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Germany; Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel; Department of Earth Sciences, Durham University, Durham, United Kingdom; Department of Earth and Environmental Sciences, Dalhousie University, Halifax, Canada; Laboratory of Ion Beam Physics, ETH Zürich, Zürich, Switzerland; Centro de Ecología Aplicada del Litoral, CONICET, Corrientes, Argentina
推荐引用方式 GB/T 7714	Scheingross J.S.,Repasch M.N.,Hovius N.,et al. The fate of fluvially-deposited organic carbon during transient floodplain storage[J],2021,561.
APA	Scheingross J.S..,Repasch M.N..,Hovius N..,Sachse D..,Lupker M..,...&Schleicher A.M..(2021).The fate of fluvially-deposited organic carbon during transient floodplain storage.Earth and Planetary Science Letters,561.
MLA	Scheingross J.S.,et al."The fate of fluvially-deposited organic carbon during transient floodplain storage".Earth and Planetary Science Letters 561(2021).