FIGURE 6.

Comparison between photochemical quenching measured in the dark in context of a heterogeneous antenna system (qP_{d het}) and quantum yield of PSII photoinhibition (Y(qI)) as functions of the light intensity in Selaginella martensii acclimated to three natural light regimes—deep shade (A), intermediate shade (B) and high light (C) (see the text for details). In all plants, stable and low values of Y(qI) correspond to stable qP_{d het} around 1. The increment in Y(qI) corresponds to a drop in qP_{d het}. Average values ± standard error for n = 3–5