Climate-related changes in peatland carbon accumulation during the last millennium

• Published in: Biogeosciences
• Main Authors: Charman, Dan J., Beilman, David W, Blaauw, Maarten, Booth, Robert K., Brewer, Simon, Chambers, Frank M., Christen, J. Andrés, Gallego-Sala, Angela, Harrison, Sandy P., Hughes, Paul D. M., Jackson, Stephen. T., Korhola, Atte, Mauquoy, Dmitri, Mitchell, Fraser. J. G., Prentice, I. Colin, Van der Linden, Marjolein, De Vleeschouwer, François, Yu, Zicheng C., Alm, Jukka, Bauer, Ilka E., Corish, Y. M. C., Garneau, Michelle, Hohl, Veronica, Huang, Yongsheng, Karofeld, Edgar, Le Roux, Gaël, Loisel, Julie, Moschen, Robert, Nichols, Jonathan E., Nieminen, Tiina M., MacDonald, Glen M., Phadtare, Netajirao R., Rausch, Nicole, Sillasoo, Ülle, Swindles, Graeme T., Tuittila, Eeva-Stiina, Ukonmaanaho, Liisa, Väliranta, Minna, Van Bellen, Simon, Van Geel, Bas, Vitt, Dale H., Zhao, Yu
• Other Authors: BIAX Consult (NETHERLANDS), Brown University (USA), Centro de Investigación en Matemáticas - CIMAT (MEXICO), Centre National de la Recherche Scientifique - CNRS (FRANCE), Chinese Academy of Sciences (CHINA), Columbia University (USA), Finnish Forest Research Institute (FINLAND), University of Gloucestershire (UNITED KINGDOM), Universität Heidelberg (GERMANY), University of Helsinki (FINLAND), Institut National Polytechnique de Toulouse - INPT (FRANCE), Macquarie University (AUSTRALIA), National Aeronautics and Space Administration - NASA (USA), Southern Illinois University - SIU (USA), University of Tartu (USA), Tallinn University (USA), University of Hawai'i at Mānoa - UH Mānoa (USA), Université Toulouse III - Paul Sabatier - UPS (FRANCE), Université du Québec à Montréal - UQAM (CANADA), University of Bristol (UNITED KINGDOM), University of Leeds (UNITED KINGDOM), Wadia Institute of Himalayan Geology - WIHG (INDIA), University of Wyoming - UW (USA), University of Eastern Finland (FINLAND), Imperial College London (UNITED KINGDOM), Forschungszentrum Jülich GmbH (GERMANY), Lehigh University (USA), Lund University (SWEDEN), Memorial University of Newfoundland - MUN (CANADA), Queen's University Belfast - QUB (UNITED KINGDOM), University of Southampton (UNITED KINGDOM), University of Aberdeen - ABDN (UNITED KINGDOM), University of Amsterdam - UvA (NETHERLANDS), University of California-Los Angeles - UCLA (USA), University of Exeter (UNITED KINGDOM), University of Dublin (REPUBLIC OF IRELAND), University of Utah (USA), Laboratoire Ecologie fonctionnelle et Environnement - EcoLab (Toulouse, France), Goddard institute for space studies - GISS (New-York, USA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: European Geosciences Union (EGU) 2013
• Subjects: Ecologie; Environnement; Peat; Climate; Carbon; Little; Ice; Age; permafrost
• Online Access: http://oatao.univ-toulouse.fr/11362/; http://oatao.univ-toulouse.fr/11362/1/Charman_11362.pdf; https://doi.org/10.5194/bg-10-929-2013

Peatlands are a major terrestrial carbon store and a persistent natural carbon sink during the Holocene, but there is considerable uncertainty over the fate of peatland carbon in a changing climate. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the global positive carbon cycle feedback. Here we use a new extensive database of peat profiles across northern high latitudes to examine spatial and temporal patterns of carbon accumulation over the past millennium. Opposite to expectations, our results indicate a small negative carbon cycle feedback from past changes in the long-term accumulation rates of northern peatlands. Total carbon accumulated over the last 1000 yr is linearly related to contemporary growing season length and photosynthetically active radiation, suggesting that variability in net primary productivity is more important than decomposition in determining long-term carbon accumulation. Furthermore, northern peatland carbon sequestration rate declined over the climate transition from the Medieval Climate Anomaly (MCA) to the Little Ice Age (LIA), probably because of lower LIA temperatures combined with increased cloudiness suppressing net primary productivity. Other factors including changing moisture status, peatland distribution, fire, nitrogen deposition, permafrost thaw and methane emissions will also influence future peatland carbon cycle feedbacks, but our data suggest that the carbon sequestration rate could increase over many areas of northern peatlands in a warmer future.