Fig. 3: Diurnal changes in photosystem II (PSII) quantum yield (Yield) and the effective functional absorption cross-section of PSII (σPSII´, A2 quanta-1) of phytoplankton assemblages grown under different O2 and CO2 treatments. | Communications Biology

Fig. 3: Diurnal changes in photosystem II (PSII) quantum yield (Yield) and the effective functional absorption cross-section of PSII (σPSII´, A2 quanta-1) of phytoplankton assemblages grown under different O2 and CO2 treatments.

From: Enhancement of diatom growth and phytoplankton productivity with reduced O2 availability is moderated by rising CO2

Fig. 3

Effective PSII quantum yield (a, c, e) and the effective functional absorption cross-section of PSII (b, d, f) at days 4, 8, and 10, respectively. Blue dots represent diel changes in photosynthetically active radiation (PAR, μmol photons m−2 s−1) during the experiment. Black symbols represent ambient O2 (AO, ~213 μM) and red symbols low O2 (LO, ~57 μM); circles represent ambient CO2 (AC, ~13 μM); triangles represent high CO2 (HC, ~27 μM). Detailed information for the mesocosms experimental features are given in Supplementary Figs. 1 and 2. The values are the means and the error bars represent standard deviations of independent biological replicates (n = 3 mesocosms). Light-colored symbols are individual data corresponding to the treatments. Blue * and red * indicate significant differences (P < 0.05, LSD test or Games–Howell test) caused by low O2 under ambient (LOAC) and elevated CO2 levels (LOHC), respectively, compared to the control treatment (AOAC).

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