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| Titel |
Effects of climate warming and declining species richness in grassland model ecosystems: acclimation of CO2 fluxes |
| VerfasserIn |
S. Vicca, P. Serrano-Ortiz, H. J. Boeck, C. M. H. M. Lemmens, I. Nijs, R. Ceulemans, A. S. Kowalski, I. A. Janssens |
| 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. 1 ; Nr. 4, no. 1 (2007-01-12), S.27-36 |
| Datensatznummer |
250001496
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| Publikation (Nr.) |
 copernicus.org/bg-4-27-2007.pdf |
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| Zusammenfassung |
| To study the effects of warming and declining species richness on the carbon
balance of grassland communities, model ecosystems containing one, three or
nine species were exposed to ambient and elevated (ambient +3°C) air
temperature. In this paper, we analyze measured ecosystem CO2 fluxes to
test whether ecosystem photosynthesis and respiration had acclimated to
warming after 28 months of continuous heating, and whether the degree of
acclimation depended on species richness. In order to test whether
acclimation occurred, short term temperature response curves were
established for all communities in both treatments. At similar temperatures,
lower flux rates in the heated communities as compared to the unheated
communities would indicate thermal acclimation. Because plant cover was
significantly higher in the heated treatment, we normalized the data for
plant cover. Subsequently, down-regulation of both photosynthesis and
respiration was observed. Although CO2 fluxes were larger in
communities with higher species richness, species richness did not affect
the degree of acclimation to warming. These results imply that models need
to take thermal acclimation into account to simulate photosynthesis and
respiration in a warmer world. |
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