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| Titel |
The full greenhouse gas balance of an abandoned peat meadow |
| VerfasserIn |
D. M. D. Hendriks, J. Huissteden, A. J. Dolman, M. K. Molen |
| 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 ; 4, no. 3 ; Nr. 4, no. 3 (2007-06-27), S.411-424 |
| Datensatznummer |
250001736
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| Publikation (Nr.) |
 copernicus.org/bg-4-411-2007.pdf |
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| Zusammenfassung |
Globally, peat lands are considered to be a sink of CO2, but a source
when drained. Additionally, wet peat lands are thought to emit considerable
amounts of CH4 and N2O. Hitherto, reliable and integrated
estimates of emissions and emission factors for this type of land cover have
been lacking and the effects of wetland restoration on methane emissions
have been poorly quantified. In this paper we estimate the full greenhouse
gas (GHG) balance of a restored natural peat land by determining the fluxes
of CO2, CH4 and N2O through atmosphere and water, while
accounting for the different Global Warming Potentials (GWP's).
The site is an abandoned agricultural peat meadow, which has been converted
into a wetland nature reserve ten years ago, after which the water level was
raised. GHG fluxes were measured continuously with an eddy covariance system
(CO2) and flux chamber measurements (CH4 and N2O).
Meteorological and hydrological measurements were collected as well. With
growing seasons of respectively 192, 168 and 129 days, the annual net
ecosystem exchange of CO2 (NEE) was −446+±83 g C m−2 yr−1
for 2004, −311±58 g C m−2 yr−1 for 2005 and −232±57 g m−2 yr−1
for 2006. Ecosystem respiration (Reco) was estimated
as 869±668 g C m−2 yr−1 for 2004, 866±666 g C m−2 yr−1
for 2005 and 924±711 g C m−2 yr−1 for 2006.
CH4 emissions from the saturated land and water surfaces were high
compared to the relatively dry land. Annual weighted CH4 emissions were
31.27±20.40 g C m−2 yr−1 for 2005 and 32.27±21.08 g C m−2 yr−1
for 2006. N2O fluxes were too low to be of significance. The
water balance of the area was dominated by precipitation and
evapotranspiration and therefore fluxes of carbon and CH4 through
seepage, infiltration and drainage were relatively small (17.25 g C m−2 yr−1).
The carbon-balance consisted for the largest part of CO2
uptake, CO2 respiration and CH4 emission from water saturated land
and water. CO2 emission has decreased significantly as result of the
raised water table, while CH4 fluxes have increased. In GWP's the area
was a small net GHG sink given as CO2-equiv. of −86 g m−2 yr−1 (over a 100-year period). |
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