Denitrification triggered by nitrogen addition in Sphagnum magellanicum peat - Université de Rennes Accéder directement au contenu
Article Dans Une Revue Biogeochemistry Année : 2011

Denitrification triggered by nitrogen addition in Sphagnum magellanicum peat

Résumé

Ombrotrophic (rain-fed) Sphagnum-mires do not significantly contribute to gaseous nitrogen (N) emissions to the atmosphere. However, increasing levels of N deposition reduce Sphagnum growth and moss cover. As a consequence, higher amounts of mineral N reach the underlying peat beneath the moss layer. The aim of our work was to determine the effects of supplementary N inputs to peat beneath Sphagnum magellanicum carpets. Peat cores were incubated in controlled laboratory conditions of temperature and humidity, and the impact of increasing N inputs was evaluated on denitrification rates, basal respiration and methane emissions. Rates of denitrification were quickly stimulated by addition of 1 g N m-2 but rates were not significantly elevated in the short-term (9 days) by further additions of up to 10 g N m-2. Over a longer term period (up to 45 days), denitrification rates followed an exponential (10 g N m-2 addition) or a gamma (1 g N m-2) function. Findings from this study support the hypothesis that mineral-N addition in atmospheric deposition will have a negative effect on peat biogeochemistry, by modifying its N sink capacity via denitrification leading to a potential increase in N2O emissions.

Dates et versions

hal-00671111 , version 1 (16-02-2012)

Identifiants

Citer

Andre-Jean Francez, Gilles Pinay, Nathalie Le Bris-Josselin, Berwyn L. Williams. Denitrification triggered by nitrogen addition in Sphagnum magellanicum peat. Biogeochemistry, 2011, 106 (3), pp.435-441. ⟨10.1007/s10533-010-9523-5⟩. ⟨hal-00671111⟩
105 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More