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| Titel |
Tundra methane emission is moderated by methane oxidation by symbiotic methanotrophs in Sphagnum |
| VerfasserIn |
J. van Huissteden, C. Berrittella, N. Kip, F. J. W. Parmentier, H. J. M. Op den Camp, M. S. M. Jetten, A. J. Dolman, T. C. Maximov |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250023610
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| Zusammenfassung |
| CH4 emission from arctic wetlands is a potential positive feedback to climate change.
However, these emissions show a strong spatial variation. In a northeast Siberian
tundra area spatial variation over an order of magnitude (1-60 mg CH4 m2hr-1)
has been observed in wetland vegetations with a similar water table. These spatial
differences are related to vegetation type. Emission increases in the order submerged
Sphagnum hollows > Carex/Eriophorum meadows > Floodplain sedge and grasses
vegetation.
We present evidence that the low emission of Sphagnum vegetations is at least partly
caused by within-plant oxidation of CH4 by symbiotic methanotrophic bacteria. Observed
oxidation rates in Sphagnum samples are 0.5 and 80 micromol CH4g-1 d-1on a dry weight
basis. Samples from submerged sites show the highest oxidation rates, while samples from
Sphagnum hummocks show negligible oxidation. Since Sphagnum vegetation covers large
areas of arctic wetlands, emission estimates should take symbiotic CH4 oxidation into
account.
Next to CH4 oxidation, the differences in emission can be attributed to differences in
ecosystem net primary production (NPP) which is probably lowest in the oligotrophic
Sphagnum sites and highest on the floodplain where flood water adds nutrients to the
ecosystem. |
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