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| Titel |
Long term effects of fen restoration: Parameterization of net ecosystem exchange models along a land use-degradation gradient |
| VerfasserIn |
L. Bergmann, M. Drösler, R. Schultz, A. Freibauer, H. Jungkunst, B. Höll |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250045328
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| Zusammenfassung |
| In combination with fluctuating water regimes and extreme variations in weather conditions
expected through climate change, continual disturbance to the soils through peat use poses a
risk to the carbon storage capacities and sequestration potentials of peatlands. Restoration
and/ or extensive use of peatlands are strategies to optimize vegetation and hydrological
balance within these sensitive ecosystems. Our goal was to determine the long term effects
of fen restoration on CO2 fluxes and to identify the driving parameters causing
differential fluxes along a disturbance gradient. This study aimed specifically to
provide a CO2-C flux dataset to determine net ecosystem exchange (NEE) in restored
temperate fens ecosystems. A climate controlled chamber system was used for
measuring instantaneous NEE over the entire year in the Donauried in 2005 and in the
Loisach-Kochelsee fens in 2006, both in southern Germany. The sites were chosen
to represent both a management gradient (from intensive grasslands and crops to
long-term restored Carex lawns) and a water table gradient (-78 cm below surface to
-1 cm below surface). NEE was measured using the closed chamber technique,
allowing for separation of NEE into gross ecosystem production (GEP) and ecosystem
respiration (Reco). In both study areas, management strongly influenced ecosystem
respiration and GPP and thus NEE, where Reco remained a strong determinant of NEE
balances. Whereas the managed-degraded sites are acting as sources of CO2, a
positive effect of restoration is seen in terms of NEE exchange. The restored sites are
either acting as significant sinks for CO2 (Donauried old restored sites) or are have
significantly lower emissions as the managed-degraded sites. NEE values ranged
from 1041 g CO2-C m2 a1source to the atmosphere in a two cut grassland to a
-130 g CO2-C m2 a1sinkin the long-term restored unmanaged Carex paniculata
site. Reco was highest in grassland sites and lowest in the restored Carex sites. A
micro-water table gradient in the restored sites offered additional insight to the
differential fluxes. An indication of a time effect of restoration on NEE was seen in
comparing short-term and long-term restored sites. Our results indicate that shifting
management intensities from intensive to extensive, as well as raising the water table to
near surface levels are viable options for climate friendly peatland management. |
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