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| Titel |
Observations of the uptake of carbonyl sulfide (COS) by trees under elevated atmospheric carbon dioxide concentrations |
| VerfasserIn |
L. Sandoval-Soto, M. Kesselmeier, V. Schmitt, A. Wild, J. Kesselmeier |
| 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 ; 9, no. 8 ; Nr. 9, no. 8 (2012-08-03), S.2935-2945 |
| Datensatznummer |
250007227
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| Publikation (Nr.) |
 copernicus.org/bg-9-2935-2012.pdf |
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| Zusammenfassung |
| Global change forces ecosystems to adapt to elevated atmospheric
concentrations of carbon dioxide (CO2). We understand that carbonyl
sulfide (COS), a trace gas which is involved in building up the
stratospheric sulfate aerosol layer, is taken up by vegetation with the same
triad of the enzymes which are metabolizing CO2, i.e.
ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco),
phosphoenolpyruvate carboxylase (PEP-Co) and carbonic anhydrase (CA).
Therefore, we discuss a physiological/biochemical acclimation of these
enzymes affecting the sink strength of vegetation for COS. We investigated
the acclimation of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers
under elevated CO2, and determined the exchange characteristics and the
content of CA after a 1–2 yr period of acclimation from 350 ppm to 800 ppm
CO2. We demonstrate that a compensation point, by definition, does not
exist. Instead, we propose to discuss a point of uptake affinity (PUA). The
results indicate that such a PUA, the CA activity and the deposition
velocities may change and may cause a decrease of the COS uptake by plant
ecosystems, at least as long as the enzyme acclimation to CO2 is not
surpassed by an increase of atmospheric COS. As a consequence, the
atmospheric COS level may rise causing an increase of the radiative forcing
in the troposphere. However, this increase is counterbalanced by the
stronger input of this trace gas into the stratosphere causing a stronger
energy reflection by the stratospheric sulfur aerosol into space (Brühl
et al., 2012). These data are very preliminary but may trigger a discussion
on COS uptake acclimation to foster measurements with modern analytical
instruments. |
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