ABSTRACT Several hypotheses have been proposed to explain recent, widespread increases in concentrations of dissolved organic carbon (DOC) in the surface waters of glaciated landscapes

across eastern North America and northern and central Europe1,2,3. Some invoke anthropogenic forcing through mechanisms related to climate change3,4,5, nitrogen deposition6 or changes in

land use7, and by implication suggest that current concentrations and fluxes are without precedent. All of these hypotheses imply that DOC levels will continue to rise, with unpredictable

consequences for the global carbon cycle. Alternatively, it has been proposed that DOC concentrations are returning toward pre-industrial levels as a result of a gradual decline in the

concentrations have increased in proportion to the rates at which atmospherically deposited anthropogenic sulphur and sea salt have declined. We conclude that acid deposition to these

ecosystems has been partially buffered by changes in organic acidity and that the rise in DOC is integral to recovery from acidification. Over recent decades, deposition-driven increases in

organic matter solubility may have increased the export of DOC to the oceans, a potentially important component of regional carbon balances11. The increase in DOC concentrations in these

regions appears unrelated to other climatic factors. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution ACCESS OPTIONS

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institutional subscriptions * Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS THE LAND–OCEAN ARCTIC CARBON CYCLE Article 06 February 2025 TEMPERATURE

SEASONALITY REGULATES ORGANIC CARBON BURIAL IN LAKE Article Open access 26 January 2025 CHANGES IN COUPLED CARBON‒NITROGEN DYNAMICS IN A TUNDRA ECOSYSTEM PREDATE POST-1950 REGIONAL WARMING

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references ACKNOWLEDGEMENTS We thank the LRTAP Working Group on Effects and the EU 6th Framework Programme Euro-limpacs for support in the production and analysis of international,

quality-controlled, comparable data. We also acknowledge the work of the ICP Waters Programme Centre at the Norwegian Institute of Water Research (NIVA), where the data were collated,

verified and archived. The authors are indebted to many colleagues and organisations who provided data for this assessment, including: T. A. Clair, S. Couture, C. Gagnon, D. K. McNicol, R.

C. Weeber, A. Paterson (Canada); J. S. Kahl, J. Kellogg, K. Roy, M. R. Hale, D. R. DeWalle (USA); the Finnish Environment Institute (SYKE) and Regional Environment Centres; the Norwegian

Institute of Water Research (NIVA); the Swedish Environmental Protection Agency (Naturvårdsverket); and the UK Acid Waters Monitoring Network (supported by the Department for Environment

Food and Rural Affairs) and supporting laboratories at: Fisheries Research Services, Pitlochry; Centre for Ecology and Hydrology, Wallingford; and the Environment Agency Llanelli. The

information in this document has been funded in part by the US Environmental Protection Agency. It has been subjected to review by the National Health and Environmental Effects Research

Laboratory, and approved for publication. Approval does not signify that the contents reflect the views of the Agency, nor does mention of trade names or commercial products constitute

endorsement or recommendation for use. AUTHOR CONTRIBUTIONS D.T.M. and J.L.S. formulated the working hypothesis and analysed and interpreted the trend data. C.D.E. and H.A.d.W. contributed

to the development of the hypothesis, assisted in the interpretation of the data, provided additional text and edited the manuscript. M.F., T.H., A.W., B.L.S., D.S.J., B.K. and J. Vuorenmaa

provided data and commented on the text. J.K. provided advice and ideas on processes and contributed data from the Czech Republic (not included in the final analysis due to number and length

of time series) consistent with the hypothesis. J. Vesely contributed advice, ideas and data in the early stages of development of our work. AUTHOR INFORMATION Author notes * Donald T.

Monteith and John L. Stoddard: These authors contributed equally to this work. * Josef Vesely: Deceased. AUTHORS AND AFFILIATIONS * Environmental Change Research Centre, UCL, London, WC1E

6BT, UK , Donald T. Monteith * US EPA, Corvallis, Oregon 97333, USA , John L. Stoddard * Centre for Ecology and Hydrology, Bangor, LL57 2UW, UK , Christopher D. Evans * Norwegian Institute

for Water Research, N-0349 Oslo, Norway Heleen A. de Wit, Tore Høgåsen & Brit Lisa Skjelkvåle * Finnish Environment Institute, PO Box 140, FI-00251 Helsinki, Finland , Martin Forsius 

& Jussi Vuorenmaa * Department of Environment Assessment SLU, SE-75007 Uppsala, Sweden Anders Wilander * Environment Canada, Burlington, Ontario, L7R4A6, Canada , Dean S. Jeffries *

Ontario Ministry of the Environment, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada , Bill Keller * Biology Centre, Institute of Hydrobiology, 37005 České Budějovice, Czech

Republic Jiri Kopácek * Czech Geological Survey, 152 00 Prague, Czech Republic Josef Vesely Authors * Donald T. Monteith View author publications You can also search for this author inPubMed

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can also search for this author inPubMed Google Scholar * Tore Høgåsen View author publications You can also search for this author inPubMed Google Scholar * Anders Wilander View author

publications You can also search for this author inPubMed Google Scholar * Brit Lisa Skjelkvåle View author publications You can also search for this author inPubMed Google Scholar * Dean S.

Jeffries View author publications You can also search for this author inPubMed Google Scholar * Jussi Vuorenmaa View author publications You can also search for this author inPubMed Google

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inPubMed Google Scholar * Josef Vesely View author publications You can also search for this author inPubMed Google Scholar CORRESPONDING AUTHOR Correspondence to Donald T. Monteith.

SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION The file contains Supplementary Figures S1-S3 and Supplementary Tables S1-S5 with Legends. (PDF 744 kb) RIGHTS AND PERMISSIONS Reprints

and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Monteith, D., Stoddard, J., Evans, C. _et al._ Dissolved organic carbon trends resulting from changes in atmospheric deposition

chemistry. _Nature_ 450, 537–540 (2007). https://doi.org/10.1038/nature06316 Download citation * Received: 22 December 2006 * Accepted: 24 September 2007 * Issue Date: 22 November 2007 *

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