Gaseous nitrogen loss from a restored peatland buffer zone

Large losses of N in gaseous form are commonly related to waterlogged conditions combined with high N mineralisation rates. N2O production, primarily through the denitrification process, may be a quantitatively substantial fraction of the total N loss from peatlands. We measured gaseous N loss from a restored peatland buffer zone in central Finland for three consecutive years with (potential flux) and without (actual flux) acetylene inhibition. Special attention was paid to N2O fluxes in relation to NO3− addition and soil temperature. Large spatial and temporal variations in N2O fluxes were found. N2O losses over the 2 y following NO3− treatment ranged from 5 kg N ha−1 y−1 with low NO3− addition in soil water to 20 kg N ha−1 y−1 with high NO3− addition and 3.5 kg N ha−1 y−1 in the control area. The total gaseous N loss from the site was approximately 15% of the added N (45 kg N y−1) during the first 2 y following NO3− addition. Gaseous N loss can play an important role in the removal of N from the restored peatland buffer zone.