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| Titel |
High methane emissions dominated annual greenhouse gas balances 30 years after bog rewetting |
| VerfasserIn |
M. Vanselow-Algan, S. R. Schmidt, M. Greven, C. Fiencke, L. Kutzbach, E.-M. Pfeiffer |
| 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 ; 12, no. 14 ; Nr. 12, no. 14 (2015-07-28), S.4361-4371 |
| Datensatznummer |
250118034
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| Publikation (Nr.) |
 copernicus.org/bg-12-4361-2015.pdf |
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| Zusammenfassung |
| Natural peatlands are important carbon sinks and sources of methane
(CH4). In contrast, drained peatlands turn from a carbon sink to a
carbon source and potentially emit nitrous oxide (N2O). Rewetting of
peatlands thus potentially implies climate change mitigation. However, data
about the time span that is needed for the re-establishment of the carbon
sink function by restoration are scarce. We therefore investigated the annual
greenhouse gas (GHG) balances of three differently vegetated sites of a bog
ecosystem 30 years after rewetting. All three
vegetation communities turned out to be sources of carbon dioxide (CO2)
ranging between 0.6 ± 1.43 t CO2 ha−2 yr−1
(Sphagnum-dominated vegetation) and 3.09 ± 3.86 t CO2 ha−2 yr−1 (vegetation dominated by heath).
While accounting for the different global warming potential (GWP) of
CO2, CH4 and N2O, the annual GHG balance was calculated.
Emissions ranged between 25 and 53 t CO2-eq ha−1 yr−1 and were dominated by large
emissions of CH4 (22–51 t CO2-eq ha−1 yr−1),
with highest rates found at purple moor grass (Molinia caerulea) stands. These are to our
knowledge the highest CH4 emissions so far reported for bog ecosystems
in temperate Europe. As the restored area was subject to large fluctuations
in the water table, we assume that the high CH4 emission rates were caused
by a combination of both the temporal inundation of the easily decomposable
plant litter of purple moor grass and the plant-mediated transport through
its tissues. In addition, as a result of the land use history, mixed soil
material due to peat extraction and refilling can serve as an explanation.
With regards to the long time span passed since rewetting, we note that the
initial increase in CH4 emissions due to rewetting as described in the
literature is not inevitably limited to a short-term period. |
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