Fig 16.
Differences in the effective quantum yield (ΔF/Fm′) of PS II measured at two different natural substrate (sandstone and limestone) on eight selected strains (see Figs 14–15 for measured data). Differences were evaluated by post hoc comparisons of nonparametric Friedman two-way ANOVA tests (see Figs 8–13 legend for further explanation). Filled and empty circles display positive and negative differences in mean ranks, respectively, varying from −6 to 6 (see the colour shade legend). Significant differences as determined by Friedman two-way ANOVA tests are indicated by asterisks (***P < 0.001, **P < 0.01, *P < 0.05).