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| Titel |
Methanotrophs Contribute to Peatland Nitrogen |
| VerfasserIn |
Tuula Larmola, Sanna M. Leppänen, Eeva-Stiina Tuittila, Maija Aarva, Päivi Merilä, Hannu Fritze, Marja Tiirola |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250123657
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| Publikation (Nr.) |
 EGU/EGU2016-2949.pdf |
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| Zusammenfassung |
| Atmospheric nitrogen (N2) fixation is potentially an important N input mechanism to
peatland ecosystems, but the extent of this process may have been underestimated because of
the methods traditionally used inhibit the activity of methanothrophs. We examined the
linkage of methane (CH4) oxidation and N2 fixation using 15N2 technique. Dominant flark
and hummock Sphagnum species were collected from twelve pristine peatlands in
Siikajoki, Finland, which varied in age from 200 to 2,500 y due to the postglacial
rebound. The mosses were incubated in a two-day field 15N2 and 13CH4 pulse
labelling experiment and the incorporation of 15N2 and 13CH4 in biomass was
measured with Isotope Ratio Mass Spectrometer. The rates of Sphagnum-associated
N2 fixation (0.1-2.9 g N m-2 y-1) were up to 10 times the current N deposition
rates. Methane-induced N2 fixation contributed to over 1/3 of moss-associated
N2 fixation in younger stages, but was switched off in old successional stages,
despite active CH4 oxidation in these stages. Both the N2 fixation rates and the
methanotrophic contribution to N2 fixation during peatland succession were primarily
constrained by phosphorus availability. Previously overlooked methanotrophic N
contribution may explain rapid peat and N accumulation during fen stages of peatland
development.
Reference. Larmola T., Leppänen S.M., Tuittila E.-S, Aarva M., Merilä P., Fritze
H., Tiirola M. (2014) Methanotrophy induces nitrogen fixation during peatland
development. Proceedings of the National Academy of Sciences USA 111 (2):
734-739. |
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