Differential mobilization of terrestrial carbon pools in Eurasian Arctic river basinsShow others and affiliations
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2013 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 110Article in journal (Refereed) Published
Abstract [en]
Mobilization of Arctic permafrost carbon is expected to increase with warming-induced thawing. However, this effect is challenging to assess due to the diverse processes controlling the release of various organic carbon (OC) pools from heterogeneous Arctic landscapes. Here, by radiocarbon dating various terrestrial OC components in fluvially and coastally integrated estuarine sediments, we present a unique framework for deconvoluting the contrasting mobilization mechanisms of surface vs. deep (permafrost) carbon pools across the climosequence of the Eurasian Arctic. Vascular plant-derived lignin phenol C-14 contents reveal significant inputs of young carbon from surface sources whose delivery is dominantly controlled by river runoff. In contrast, plant wax lipids predominantly trace ancient (permafrost) OC that is preferentially mobilized from discontinuous permafrost regions, where hydrological conduits penetrate deeper into soils and thermokarst erosion occurs more frequently. Because river runoff has significantly increased across the Eurasian Arctic in recent decades, we estimate from an isotopic mixing model that, in tandem with an increased transfer of young surface carbon, the proportion of mobilized terrestrial OC accounted for by ancient carbon has increased by 3-6% between 1985 and 2004. These findings suggest that although partly masked by surface carbon export, climate change-induced mobilization of old permafrost carbon is well underway in the Arctic.
Place, publisher, year, edition, pages
2013. Vol. 110
Keywords [en]
fluvial mobilization compound-specific C-14 hydrogeographic control particulate organic-carbon old carbon permafrost carbon coastal erosion residence time lena river laptev sea matter ocean transport Science & Technology - Other Topics
Research subject
SWEDARCTIC 2008, ISSS-08
Identifiers
URN: urn:nbn:se:polar:diva-1897DOI: 10.1073/pnas.1307031110OAI: oai:DiVA.org:polar-1897DiVA, id: diva2:810436
Note
ISI Document Delivery No.: 206ZC Times Cited: 14 Cited Reference Count: 55 Feng, Xiaojuan Vonk, Jorien E. van Dongen, Bart E. Gustafsson, Orjan Semiletov, Igor P. Dudarev, Oleg V. Wang, Zhiheng Montlucon, Daniel B. Wacker, Lukas Eglinton, Timothy I. Wang, Zhiheng/G-1750-2010; Semiletov, Igor/B-3616-2013; Vonk, Jorien/H-5422-2011; publist, CMEC/C-3010-2012 US National Science Foundation [OCE-9907129, OCE-0137005, OCE-0526268]; Stanley Watson Chair for Excellence in Oceanography; Eidgenossiche Technische Hochschule (ETH) Zurich; Swedish Royal Academy of Sciences; Netherlands Organization for Scientific Research-Rubicon [825.10.022]; UK Natural Environment Research Council [NE/I024798/1]; WHOI; ETH Zurich; Knut and Alice Wallenberg Foundation; Far Eastern Branch of the Russian Academy of Sciences; Swedish Research Council; US National Oceanic and Atmospheric Administration; Russian Foundation of Basic Research; Swedish Polar Research Secretariat; Nordic Council of Ministers We thank all colleagues in the International Siberian Shelf Study (ISSS) Program for support, including sampling. We thank Li Xu for assistance with AMS analyses at Woods Hole Oceanographic Institution (WHOI). Christopher Reddy is acknowledged for providing access to an HPLC system. Grants OCE-9907129, OCE-0137005, and OCE-0526268 from the US National Science Foundation, the Stanley Watson Chair for Excellence in Oceanography (to T.I.E.), and Eidgenossiche Technische Hochschule (ETH) Zurich enabled this research. O.G. acknowledges an Academy Research Fellow grant from the Swedish Royal Academy of Sciences. J.E.V. thanks the Netherlands Organization for Scientific Research-Rubicon (Grant 825.10.022) for support. B.E.v.D thanks the UK Natural Environment Research Council (Grant NE/I024798/1) for support. X.F. thanks the WHOI for a postdoctoral scholar fellowship and ETH Zurich for postdoctoral support. The ISSS program is supported by the Knut and Alice Wallenberg Foundation, the Far Eastern Branch of the Russian Academy of Sciences, the Swedish Research Council, the US National Oceanic and Atmospheric Administration, the Russian Foundation of Basic Research, the Swedish Polar Research Secretariat, and the Nordic Council of Ministers (Arctic Cooperation and Top-Level Research Initiative-Defrost programs). 14 Natl acad sciences Washington Multidisciplinary Sciences
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