Preprints
https://doi.org/10.5194/bgd-6-5339-2009
https://doi.org/10.5194/bgd-6-5339-2009
28 May 2009
 | 28 May 2009
Status: this preprint was under review for the journal BG but the revision was not accepted.

Carbon fixation prediction during a bloom of Emiliania huxleyi is highly sensitive to the assumed regulation mechanism

O. Bernard, A. Sciandra, and S. Rabouille

Abstract. Large scale precipitation of calcium carbonate in the oceans by coccolithophorids plays an important role in carbon sequestration. However, there is a controversy on the effect of an increase in atmospheric CO2 concentration on both calcification and photosynthesis of coccolithophorids. Indeed recent experiments, performed under nitrogen limitation, revealed that the associated fluxes may be slowed down, while other authors claim the reverse. We designed models to account for various scenarii of calcification and photosynthesis regulation in chemostat cultures of Emiliania huxleyi, based on different hypotheses on the regulation mechanism. These models consider that either carbon dioxide, bicarbonate, carbonate or calcite saturation state (Ω) is the regulating factor. All were calibrated to predict the same carbon fixation rate in nowadays pCO2, but they turn out to respond differently to an increase in CO2 concentration. Thus, using the four possible models, we simulated a large bloom of Emiliania huxleyi. It results that models assuming a regulation by CO32− or Ω predicted much higher carbon fluxes. The response when considering a doubled pCO2 was different and models controlled by CO2 or HCO3 led to increased carbon fluxes. In addition, the variability between the various scenarii proved to be in the same order of magnitude than the response to pCO2 increase. These sharp discrepancies reveal the consequences of model assumptions on the simulation outcome.

O. Bernard, A. Sciandra, and S. Rabouille
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
O. Bernard, A. Sciandra, and S. Rabouille
O. Bernard, A. Sciandra, and S. Rabouille

Viewed

Total article views: 1,093 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
694 339 60 1,093 53 40
  • HTML: 694
  • PDF: 339
  • XML: 60
  • Total: 1,093
  • BibTeX: 53
  • EndNote: 40
Views and downloads (calculated since 01 Feb 2013)
Cumulative views and downloads (calculated since 01 Feb 2013)

Cited

Saved

Latest update: 15 Mar 2024
Download
Altmetrics