Ayata S. D., Levy M., Aumont Olivier, Resplandy L., Tagliabue A., Sciandra A., Bernard O. (2014). Phytoplankton plasticity drives large variability in carbon fixation efficiency. Geophysical Research Letters, 41 (24), p. 8994-9000. ISSN 0094-8276.
Titre du document
Phytoplankton plasticity drives large variability in carbon fixation efficiency
Ayata S. D., Levy M., Aumont Olivier, Resplandy L., Tagliabue A., Sciandra A., Bernard O.
Source
Geophysical Research Letters, 2014,
41 (24), p. 8994-9000 ISSN 0094-8276
Phytoplankton C:N stoichiometry is highly flexible due to physiological plasticity, which could lead to high variations in carbon fixation efficiency (carbon consumption relative to nitrogen). However, the magnitude, as well as the spatial and temporal scales of variability, remains poorly constrained. We used a high-resolution biogeochemical model resolving various scales from small to high, spatially and temporally, in order to quantify and better understand this variability. We find that phytoplankton C:N ratio is highly variable at all spatial and temporal scales (5-12molC/molN), from mesoscale to regional scale, and is mainly driven by nitrogen supply. Carbon fixation efficiency varies accordingly at all scales (30%), with higher values under oligotrophic conditions and lower values under eutrophic conditions. Hence, phytoplankton plasticity may act as a buffer by attenuating carbon sequestration variability. Our results have implications for in situ estimations of C:N ratios and for future predictions under high CO2 world.
