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| Titel |
Methanol exchange between grassland and the atmosphere |
| VerfasserIn |
A. Brunner, C. Ammann, A. Neftel, C. Spirig |
| 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 (2007-06-26), S.395-410 |
| Datensatznummer |
250001735
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| Publikation (Nr.) |
 copernicus.org/bg-4-395-2007.pdf |
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| Zusammenfassung |
| Concentrations and fluxes of methanol were measured above two differently
managed grassland fields (intensive and extensive) in central Switzerland
during summer 2004. The measurements were performed with a
proton-transfer-reaction mass-spectrometer and fluxes were determined by the
eddy covariance method. The observed methanol emission showed a distinct
diurnal cycle and was strongly correlated with global radiation and water
vapour flux. Mean and maximum daily emissions were found to depend on
grassland species composition and, for the intensive field, also on the
growing state. The extensive field with a more complex species composition
had higher emissions than the graminoid-dominated intensive field, both on
an area and on a biomass basis. A simple parameterisation depending on the
water vapour flux and the leaf area index allowed a satisfying simulation of
the temporal variation of methanol emissions over the growing phase.
Accumulated carbon losses due to methanol emissions accounted for 0.024 and
0.048% of net primary productivity for the intensive and extensive field,
respectively. The integral methanol emissions over the growing periods were
more than one order of magnitude higher than the emissions related to cut
and drying events. |
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