Soil carbon residence time regulates the age of dissolved organic matter in global rivers
Abstract Riverine dissolved organic carbon (DOC) constitutes a pivotal component in the Earth’s carbon cycle, yet little is known about the global patterns, sources, and factors governing lotic DOC. Here, we integrate a global dataset and employ machine learning to generate a global atlas of riverine DOC concentration and its radiocarbon (Δ14C) and stable-carbon (δ13C) isotopic signatures. Globally, riverine DOC has an average Δ14C value of –22.5 ± 144.0‰ (radiocarbon age of 221 years), with fossil carbon contributing a minor fraction (6.7 ± 3.0%). Terrestrial and autochthonous riverine production are the dominant DOC sources (>80%) at the global scale, with contemporary terrestrial DOC predominant in tropical rivers and within-river production prominent in those within temperate and semi-arid regions. Rivers draining high-latitude regions and high-elevation sites have the lowest Δ14C values (–353‰ to –78‰; ages between 3400 and 600 years). River Δ14C-DOC values correlate with soil organic carbon and riverine particulate organic carbon Δ14C values, but river DOC has much higher Δ14C values than subsurface soils indicating that riverine DOC originates from surface rather than subsurface soils. Because warming mobilizes aged organic carbon from permafrost soils, export to and processing of old carbon in recipient aquatic systems may accelerate with climate change.
Authors
- Joshua Dean (ORCID: https://orcid.org/0000-0001-9058-7076)
- Gerard Rocher‐Ros (ORCID: https://orcid.org/0000-0001-7853-2531)
- Peter R. Leavitt (ORCID: https://orcid.org/0000-0001-9805-9307)
- L Zhang
- Travis W. Drake (ORCID: https://orcid.org/0000-0002-7564-974X)
- Jack J. Middelburg (ORCID: https://orcid.org/0000-0003-3601-9072)
- Yunlin Zhang (ORCID: https://orcid.org/0000-0002-3382-4570)
- Zhaohui Liu (ORCID: https://orcid.org/0000-0001-6771-9368)
- Chenglong Wang
- Pierre Regnier
- Weipeng Lin
- R Iestyn Woolway
- Jan Karlsson
- Robert G M Spencer
- Yongqiang Zhou (ORCID: https://orcid.org/0000-0003-1402-345X)
- Lei Zhou
Institutions
- Florida State University (US)
- Université Libre de Bruxelles (BE)
- Bangor University (GB)
- University of Applied Sciences Utrecht (NL)
- Utrecht University (NL)
- University of Regina (CA)
- Abisko Scientific Research Station (SE)
- ETH Zurich (CH)
- University of Bristol (GB)
- SystemsX.ch (CH)
- Nanjing Institute of Geography and Limnology (CN)
- Ministry of Education (MV)
- Shanghai Estuarine & Coastal Science Research Center (CN)
- University of Chinese Academy of Sciences (CN)
- Institute of Soil Science (CN)
- East China Normal University (CN)
Publication Details
- Journal
- National Science Review
- Published
- 2026-04-21
- DOI
- https://doi.org/10.1093/nsr/nwag237
- Primary Topic
- Marine and coastal ecosystems
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- UK Research and Innovation
- European Space Agency
- National Natural Science Foundation of China
- Chinese Academy of Sciences
- Youth Innovation Promotion Association of the Chinese Academy of Sciences
- Natural Sciences and Engineering Research Council of Canada
- Natural Environment Research Council
- Youth Innovation Promotion Association