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| Titel |
Effects of land use intensity on the full greenhouse gas balance in an Atlantic peat bog |
| VerfasserIn |
S. Beetz, H. Liebersbach, S. Glatzel, G. Jurasinski, U. Buczko, H. Höper |
| 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 ; 10, no. 2 ; Nr. 10, no. 2 (2013-02-15), S.1067-1082 |
| Datensatznummer |
250017519
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| Publikation (Nr.) |
 copernicus.org/bg-10-1067-2013.pdf |
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| Zusammenfassung |
Wetlands can either be net sinks or net sources of greenhouse gases (GHGs),
depending on the mean annual water level and other factors like average
annual temperature, vegetation development, and land use. Whereas drained and
agriculturally used peatlands tend to be carbon dioxide (CO2) and
nitrous oxide (N2O) sources but methane (CH4) sinks, restored (i.e.
rewetted) peatlands rather incorporate CO2, tend to be N2O neutral
and release CH4. One of the aims of peatland restoration is to decrease
their global warming potential (GWP) by reducing GHG emissions.
We estimated the greenhouse gas exchange of a peat bog restoration sequence
over a period of 2 yr (1 July 2007–30 June 2009) in an Atlantic raised bog
in northwest Germany. We set up three study sites representing different land
use intensities: intensive grassland (deeply drained, mineral fertilizer,
cattle manure and 4–5 cuts per year); extensive grassland (rewetted, no
fertilizer or manure, up to 1 cutting per year); near-natural peat bog
(almost no anthropogenic influence). Daily and annual greenhouse gas exchange
was estimated based on closed-chamber measurements. CH4 and N2O
fluxes were recorded bi-weekly, and net ecosystem exchange (NEE) measurements
were carried out every 3–4 weeks. Annual sums of CH4 and N2O
fluxes were estimated by linear interpolation while NEE was modelled.
Regarding GWP, the intensive grassland site emitted
564 ± 255 g CO2–C equivalents m−2 yr−1 and
850 ± 238 g CO2–C equivalents m−2 yr−1 in the first
(2007/2008) and the second (2008/2009) measuring year, respectively. The GWP
of the extensive grassland amounted to −129 ± 231 g CO2–C
equivalents m−2 yr−1 and 94 ± 200 g CO2–C
equivalents m−2 yr−1, while it added up to
45 ± 117 g CO2–C equivalents m−2 yr−1 and
−101 ± 93 g CO2–C equivalents m−2 yr−1 in 2007/08
and 2008/09 for the near-natural site. In contrast, in calendar year 2008 GWP
aggregated to 441 ± 201 g CO2–C equivalents
m−2 yr−1, 14 ± 162 g CO2–C equivalents
m−2 yr−1 and 31 ± 75 g CO2–C equivalents
m−2 yr−1 for the intensive grassland, extensive grassland, and
near-natural site, respectively.
Despite inter-annual variability, rewetting contributes considerably to
mitigating GHG emission from formerly drained peatlands. Extensively used
grassland on moderately drained peat approaches the carbon sequestration
potential of near-natural sites, although it may oscillate between being a
small sink and being a small source depending on inter-annual climatic
variability. |
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