Biogeosciences www.biogeosciences.net 1726-4170 1726-4189 5 5 2008 10.5194/bg-5-1387-2008 http://www.biogeosciences.net/5/1387/2008/ http://www.biogeosciences.net/5/1387/2008/bg-5-1387-2008.html http://www.biogeosciences.net/5/1387/2008/bg-5-1387-2008.pdf 1387 1393 2008-10-06 Do we miss the hot spots? – The use of very high resolution aerial photographs to quantify carbon fluxes in peatlands T. Becker tbecker@uni-greifswald.de L. Kutzbach I. Forbrich J. Schneider D. Jager B. Thees M. Wilmking Institute of Botany and Landscape Ecology, University of Greifswald, Grimmer Straße 88, 17487 Greifswald, Germany Federal Environmental Agency, Berlin, Germany Accurate determination of carbon balances in heterogeneous ecosystems often requires the extrapolation of point based measurements. The ground resolution (pixel size) of the extrapolation base, e.g. a land-cover map, might thus influence the calculated carbon balance, in particular if biogeochemical hot spots are small in size. In this paper, we test the effects of varying ground resolution on the calculated carbon balance of a boreal peatland consisting of hummocks (dry), lawns (intermediate) and flarks (wet surfaces). The generalizations in lower resolution imagery led to biased area estimates for individual micro-site types. While areas of lawns and hummocks were stable below a threshold resolution of ~60 cm, the maximum of the flark area was located at resolutions below 25 cm and was then decreasing with coarsening resolution. Using a resolution of 100 cm instead of 6 cm led to an overestimation of total CO₂ uptake of the studied peatland area (approximately 14 600 m²) of ~5% and an underestimation of total CH₄ emission of ~6%. To accurately determine the surface area of scattered and small-sized micro-site types in heterogeneous ecosystems (e.g. flarks in peatlands), a minimum ground resolution appears necessary. 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