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Titel |
Small scale controls of greenhouse gas release under elevated N deposition rates in a restoring peat bog in NW Germany |
VerfasserIn |
S. Glatzel, I. Forbrich, C. Krüger, S. Lemke, G. Gerold |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 5, no. 3 ; Nr. 5, no. 3 (2008-06-11), S.925-935 |
Datensatznummer |
250002531
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Publikation (Nr.) |
copernicus.org/bg-5-925-2008.pdf |
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Zusammenfassung |
In Central Europe, most bogs have a history of drainage and many of them are
currently being restored. Success of restoration as well as greenhouse gas
exchange of these bogs is influenced by environmental stress factors as
drought and atmospheric nitrogen deposition. We determined the methane and
nitrous oxide exchange of sites in the strongly decomposed center and less
decomposed edge of the Pietzmoor bog in NW Germany in 2004. Also, we
examined the methane and nitrous oxide exchange of mesocosms from the center
and edge before, during, and following a drainage experiment as well as
carbon dioxide release from disturbed unfertilized and nitrogen fertilized
surface peat. In the field, methane fluxes ranged from 0 to 3.8 mg m−2 h−1
and were highest from hollows. Field nitrous oxide fluxes ranged
from 0 to 574 μg m−2 h−1 and were elevated at the edge. A
large Eriophorum vaginatum tussock showed decreasing nitrous oxide release as the season
progressed. Drainage of mesocosms decreased methane release to 0, even
during rewetting. There was a tendency for a decrease of nitrous oxide
release during drainage and for an increase in nitrous oxide release during
rewetting. Nitrogen fertilization did not increase decomposition of surface
peat. Our examinations suggest a competition between vascular vegetation and
denitrifiers for excess nitrogen. We also provide evidence that the von Post
humification index can be used to explain nitrous oxide release from bogs,
if the role of vascular vegetation is also considered. An assessment of the
greenhouse gas release from nitrogen saturated restoring bogs needs to take
into account elevated release from fresh Sphagnum peat as well as from
sedges growing on decomposed peat. Given the high atmospheric nitrogen
deposition, restoration will not be able to achieve an oligotrophic
ecosystem in the short term. |
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