Fig 4. Effects of pCO_2, temperature and irradiance on the percentage of abnormal germlings of Porolithon cf. onkodes.

(a), (b) and (c) show the main effects of pCO_2, temperature and irradiance respectively (means of n = 12 (± SE)). Lower panels show the individual effects of pCO₂ and irradiance under ambient (d) and (e) high temperature (means of n = 3 (± SE)). CO₂ levels correspond to: control: 398–511 mg L^–1, medium: 550–738 mg L^–1 and high: 999–1568 mg L^–1; temperature levels to: ambient: 25–27°C and high: 27–29°C; and light levels to: high: 140–160 μmol photons m^-2 s –¹ and low: 40–60 μmol photons m^-2 s –¹. Letters above bars indicate significant groupings by post-hoc Tukey tests.