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Titel |
Agricultural peatlands: towards a greenhouse gas sink – a synthesis of a Dutch landscape study |
VerfasserIn |
A. P. Schrier-Uijl, P. S. Kroon, D. M. D. Hendriks, A. Hensen, J. van Huissteden, F. Berendse, E. M. Veenendaal |
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 ; 11, no. 16 ; Nr. 11, no. 16 (2014-08-28), S.4559-4576 |
Datensatznummer |
250117567
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Publikation (Nr.) |
copernicus.org/bg-11-4559-2014.pdf |
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Zusammenfassung |
It is generally known that managed, drained peatlands act as carbon (C)
sources. In this study we examined how mitigation through the reduction of
the intensity of land management and through rewetting may affect the
greenhouse gas (GHG) emission and the C balance of intensively managed,
drained, agricultural peatlands. Carbon and GHG balances were determined for
three peatlands in the western part of the Netherlands from 2005 to 2008 by
considering spatial and temporal variability of emissions (CO2, CH4
and N2O). One area (Oukoop) is an intensively managed grass-on-peatland area,
including a dairy farm, with the ground water level at an average annual
depth of 0.55 (±0.37) m below the soil surface. The second area (Stein)
is an extensively managed grass-on-peatland area, formerly intensively managed,
with a dynamic ground water level at an average annual depth of
0.45 (±0.35) m below the soil surface. The third area is a (since
1998) rewetted former agricultural peatland (Horstermeer), close to Oukoop
and Stein, with the average annual ground water level at a depth of
0.2 (±0.20) m below the soil surface. During the measurement campaigns
we found that both agriculturally managed sites acted as C and GHG sources
and the rewetted former agricultural peatland acted as a C and GHG sink. The
ecosystem (fields and ditches) total GHG balance, including CO2,
CH4 and N2O, amounted to 3.9 (±0.4), 1.3 (±0.5) and
−1.7 (±1.8) g CO2-eq m−2 d−1 for Oukoop, Stein and
Horstermeer, respectively. Adding the farm-based emissions to Oukoop and
Stein resulted in a total GHG emission of 8.3 (±1.0) and
6.6 (±1.3) g CO2-eq m−2 d−1, respectively. For
Horstermeer the GHG balance remained the same since no farm-based emissions
exist. Considering the C balance (uncertainty range 40–60%), the
total C release in Oukoop and Stein is 5270 and
6258 kg C ha−1 yr−1, respectively (including ecosystem and
management fluxes), and the total C uptake in Horstermeer is
3538 kg C ha−1 yr−1. Water bodies contributed significantly to
the terrestrial GHG balance because of a high release of CH4.
Overall, this study suggests that managed peatlands are large sources of
GHGs and C, but, if appropriate measures are taken, they can be turned back
into GHG and C sinks within 15 years of abandonment and rewetting. The shift
from an intensively managed grass-on-peat area (Oukoop) to an extensively managed
one (Stein) reduced the GHG emissions mainly because N2O
emission and farm-based CH4 emissions decreased. |
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