Contrasting denitrifier communities relate to contrasting N2O emission patterns from acidic peat soils in arctic tundra.

ABSTRACT: Cryoturbated peat circles (that is, bare surface soil mixed by frost action; pH 3-4) in the Russian discontinuous permafrost tundra are nitrate-rich 'hotspots' of nitrous oxide (N(2)O) emissions in arctic ecosystems, whereas adjacent unturbated peat areas are not. N(2)O was produced and subsequently consumed at pH 4 in unsupplemented anoxic microcosms with cryoturbated but not in those with unturbated peat soil. Nitrate, nitrite and acetylene stimulated net N(2)O production of both soils in anoxic microcosms, indicating denitrification as the source of N(2)O. Up to 500 and 10 μM nitrate stimulated denitrification in cryoturbated and unturbated peat soils, respectively. Apparent maximal reaction velocities of nitrite-dependent denitrification were 28 and 18 nmol N(2)O g(DW)(-1) h(-1), for c

SUBMITTER: Palmer K 

PROVIDER: S-EPMC3329112 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature