Ayata S. D. auteur aut IRD Levy M. auteur aut IRD Aumont Olivier auteur aut IRD Resplandy L. auteur aut IRD Tagliabue A. auteur aut IRD Sciandra A. auteur aut IRD Bernard O. auteur aut IRD text journalArticle eng text/pdf born digital access 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. specialized phytoplankton production stoichiometry model ATLANTIQUE 032 036 020 41 24 8994-9000 2014 0094-8276 https://www.documentation.ird.fr/hor/fdi:010063936 10.1002/2014gl062249 0094-8276 [F B010063936] https://www.documentation.ird.fr/hor/fdi:010063936 https://www.documentation.ird.fr/intranet/publi/2015/03/010063936.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-04-07 2021-04-10 fdi:010063936 fre