Premium
Dinitrogen and nitrous oxide exchanges from an undrained monolith fen: short‐term responses following nitrate addition
Author(s) -
Roobroeck D.,
ButterbachBahl K.,
Brüggemann N.,
Boeckx P.
Publication year - 2010
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/j.1365-2389.2010.01269.x
Subject(s) - tussock , nitrous oxide , peat , denitrification , nitrate , sink (geography) , ecosystem , nitrogen , environmental chemistry , soil water , chemistry , nitrification , environmental science , ecology , soil science , biology , geography , cartography , organic chemistry
Gaseous nitrogen exchanges from undrained peat soils and the effect of external nitrate input are poorly understood. This paper reports net N 2 and N 2 O exchanges as well as the short‐term responses to nitrate addition from contrasting tussock and hollow soil habitats in an undrained monolith fen ecosystem located in northeast Poland. Gaseous N exchange rates were quantified by means of a He substitution technique. The net N 2 production in hollows (2.53 mg N m −2 hour −1 ) was significantly higher than in tussocks (1.04 mg N m −2 hour −1 ). Hollows also constituted a marked N 2 O sink (−3.04 µg N m −2 hour −1 ), while tussocks were a source for atmospheric N 2 O (2.08 µg N m −2 hour −1 ). Following amendment by NO 3 − , at a rate similar to atmospheric NO 3 − deposition (wet + dry), hollows showed a drastic shift to net production of N 2 O but a non‐significant increase in N 2 production. In tussocks only a minor increase of N 2 and N 2 O production was observed after NO 3 − addition. This study emphasizes the influence of physico‐chemical conditions and biotic resource competition on the rates and responses of microbial denitrification in undrained fen ecosystems. Inferring a simple field‐scale estimation of gaseous N emission suggests that undrained, monolith fen ecosystems constitute substantial sources of N 2 (1.79 mg N m −2 hour −1 ) and considerable sinks for N 2 O (−0.96 µg N m −2 hour −1 ). These findings are of importance to further improve greenhouse gas budgeting and assess the impacts of global change on undrained fen ecosystems.