Biogeosciences www.biogeosciences.net 1726-4170 1726-4189 5 5 2008 10.5194/bg-5-1475-2008 http://www.biogeosciences.net/5/1475/2008/ http://www.biogeosciences.net/5/1475/2008/bg-5-1475-2008.html http://www.biogeosciences.net/5/1475/2008/bg-5-1475-2008.pdf 1475 1491 2008-10-31 Peatlands and the carbon cycle: from local processes to global implications – a synthesis J. Limpens juul.Limpens@wur.nl F. Berendse C. Blodau J. G. Canadell C. Freeman J. Holden N. Roulet H. Rydin G. Schaepman-Strub Nature Conservation and Plant Ecology Group, Wageningen University, Wageningen, The Netherlands Limnological Research Station and Department of Hydrology, University of Bayreuth, 95440 Bayreuth, Germany Global Carbon Project, CSIRO Marine and Atmospheric Research, GPO Box 3023, Canberra, ACT 2601, Australia School of Biological Sciences, Bangor University, Wales, LL57 2UW, UK School of Geography, University of Leeds, Leeds, LS2 9JT, UK Department of Geography, McGill University, 805, Sherbrooke Street West, Montréal, Québec, H3A 2K6, Canada Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Villavägen 14, 752 36 Uppsala, Sweden Peatlands cover only 3% of the Earth's land surface but boreal and subarctic peatlands store about 15–30% of the world's soil carbon (C) as peat. Despite their potential for large positive feedbacks to the climate system through sequestration and emission of greenhouse gases, peatlands are not explicitly included in global climate models and therefore in predictions of future climate change. In April 2007 a symposium was held in Wageningen, the Netherlands, to advance our understanding of peatland C cycling. This paper synthesizes the main findings of the symposium, focusing on (i) small-scale processes, (ii) C fluxes at the landscape scale, and (iii) peatlands in the context of climate change. <br><br> The main drivers controlling C fluxes are largely scale dependent and most are related to some aspects of hydrology. Despite high spatial and annual variability in Net Ecosystem Exchange (NEE), the differences in cumulative annual NEE are more a function of broad scale geographic location and physical setting than internal factors, suggesting the existence of strong feedbacks. 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