Greenhouse gas dynamics of a well-drained afforested agricultural peatland

About a quarter of the global anthropogenic greenhouse gas emissions are attributable to agriculture, forestry and other land use. Few studies of afforested drained peatlands have measured exchanges of all three major greenhouse gases (GHG) at a given site, leading to uncertainty in estimated GHG budgets. Thus, we measured forest floor exchange of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) at a well-drained afforested peatland in southern Sweden. The CO2 emissions (76000 kg ha(-1) a(-1); SE 6000) were large compared with previous measurements at similar sites, which may have been partly due to a measurement technique that did not underestimate the flux. A net CH4 uptake of 4.4 kg ha(-1) a(-1) (SE 0.41) and a net N2O emission of 2.7 kg ha(-1) a(-1) (SE 0.23) were found, which agreed well with published models relating fluxes to stand biomass (CH4 models) or soil C:N ratio (N2O models).