Emission of gaseous nitrogen oxides in soils of boreal forests (review)

Abstract

Denitrification losses of nitrogen-containing gases in the biome of boreal forests are discussed. In the soils of coniferous and deciduous forests of Western Europe, 0.57 ± 0.2 and 1.0 ± 0.2 kg N-N2O/ha/ year are lost during denitrification. In North America this figure was 0.35 ± 0.29 kg N-N2O/ha/yr for all stands. The emission of N2O from forest soils correlated with the input of nitrogen from the atmosphere withr= 0.47 in coniferous forests and withr= 0.68 in deciduous plantations, returning to the atmosphere up to 30% of the nitrogen supplied with atmospheric precipitation. With a high input of nitrogen from the atmosphere, the emission of nitrogen-containing gases reached 20 kg N /ha /yr. Of these, NO, N2O, and N2accounted for 21, 15, and 64%. Measurements of NO and especially N2emissions remain very rare, leading to incomplete estimates of denitrification losses. Denitrification remains the most complex process in the nitrogen cycle, with no definitive methods for measuring it.