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| Titel |
CO2 exchange and carbon balance in two grassland sites on eutrophic drained peat soils |
| VerfasserIn |
E. M. Veenendaal, O. Kolle, P. A. Leffelaar, A. P. Schrier-Uijl, J. Huissteden, J. Walsem, F. Möller, F. Berendse |
| 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. 6 ; Nr. 4, no. 6 (2007-11-21), S.1027-1040 |
| Datensatznummer |
250001996
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| Publikation (Nr.) |
 copernicus.org/bg-4-1027-2007.pdf |
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| Zusammenfassung |
In this study we investigated the role of intensive and extensive dairy farm
practices on CO2 exchange and the carbon balance of peatlands by means
of eddy covariance (EC) measurements. Year long EC measurements were made in
two adjacent farm sites on peat soil in the western part of the Netherlands.
One site (Stein) is a new meadow bird reserve and is managed predominantly
by mowing in June and August. The second site (Oukoop) is an intensive dairy
farm.
Maximum photosynthetic uptake of the grass sward (range 2 to 34 μmol
CO2 m−2 s−1) showed a close and similar linear relationship
with Leaf Area Index (LAI; range 1 to 5) except in maturing hay meadows,
where maximum photosynthetic uptake did not increase further. Apparent quantum
yield varied between 0.02 and 0.08 (mean 0.045) μmol CO2 μmol−1
photons at both sites and was significantly correlated with LAI
during the growth season. Ecosystem Respiration at 10°C (R10)
calculated from the year round data set was 3.35 μmol CO2 m−2 s−1
at Stein and 3.69 μmol CO2 m−2 s−1 at Oukoop.
Both sites were a source of carbon in winter and a sink during summer with
net ecosystem exchange varying between 50 to 100 mmol CO2 m−2 d−1
in winter to below −400 mmol CO2 m−2 d−1 in summer.
Periodically, both sites became a source after mowing. Net annual ecosystem
exchange (NEE) for Stein was −5.7 g C m−2 a−1 and for Oukoop
133.9 g C m−2 a−1.
When biomass removal, manure applications and estimates of methane emissions
ware taken into account, both eutrophic peat meadows are a strong source for
C around 420 g C m−2 a−1. |
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