Fig. 4. Changes in chlorophyll a fluorescence parameters in situ over a day. A) Maximum
quantum yield of photosystem II (Fv/Fm) B) Non-photochemical quenching (NPQ) C)
Effective absorption cross-section serving PSII photochemistry (σPSII, Å2 quantum−1
)
and D) The ratio of initial fluorescence during a saturating flash (F0) to σPSII. Data are the
averages of n = 4 biological replicates, error bars show 1 standard deviation