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| Titel |
Precipitation as driver of carbon fluxes in 11 African ecosystems |
| VerfasserIn |
L. Merbold, J. Ardö, A. Arneth, R. J. Scholes, Y. Nouvellon, A. Grandcourt, S. Archibald, J. M. Bonnefond, N. Boulain, N. Brueggemann, C. Bruemmer, B. Cappelaere, E. Ceschia, H. A. M. El-Khidir, B. A. El-Tahir, U. Falk, J. Lloyd, L. Kergoat, V. Dantec, E. Mougin, M. Muchinda, M. M. Mukelabai, D. Ramier, O. Roupsard, F. Timouk, E. M. Veenendaal, W. L. Kutsch |
| 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 ; 6, no. 6 ; Nr. 6, no. 6 (2009-06-18), S.1027-1041 |
| Datensatznummer |
250003837
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| Publikation (Nr.) |
 copernicus.org/bg-6-1027-2009.pdf |
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| Zusammenfassung |
This study reports carbon and water fluxes between the land surface and
atmosphere in eleven different ecosystems types in Sub-Saharan Africa, as
measured using eddy covariance (EC) technology in the first two years of the
CarboAfrica network operation. The ecosystems for which data were available
ranged in mean annual rainfall from 320 mm (Sudan) to 1150 mm (Republic of
Congo) and include a spectrum of vegetation types (or land cover) (open
savannas, woodlands, croplands and grasslands). Given the shortness of the
record, the EC data were analysed across the network rather than
longitudinally at sites, in order to understand the driving factors for
ecosystem respiration and carbon assimilation, and to reveal the different
water use strategies in these highly seasonal environments.
Values for maximum net carbon assimilation rates (photosynthesis) ranged
from −12.5 μmol CO2 m−2 s−1 in a dry, open
Millet cropland (C4-plants)
up to −48 μmol CO2 m−2 s−1 for a tropical moist
grassland. Maximum carbon assimilation rates were highly correlated with
mean annual rainfall (r2=0.74). Maximum photosynthetic uptake rates
(Fpmax) were positively related to satellite-derived fAPAR.
Ecosystem respiration was dependent on temperature at all sites, and was
additionally dependent on soil water content at sites receiving less than
1000 mm of rain per year. All included ecosystems dominated by
C3-plants, showed a strong decrease in 30-min assimilation rates
with increasing water vapour pressure deficit above 2.0 kPa. |
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