Table 1 Chlorophyll fluorescence parameters measurable with FluorCam systems (following nomenclature in [6] or [36] regarding Rfd, respectively)

F, F′

Steady state fluorescence emission from dark- or light-adapted leaf, respectively

F₀, F₀′

Minimal chlorophyll fluorescence intensity measured in the dark- or light-adapted state, respectively

F_m, F_m′

Maximal chlorophyll fluorescence intensity measured in the dark- or light-adapted state, respectively

F_v, F_v′

Variable chlorophyll fluorescence (F_m-F₀) measured in the dark- or light-adapted state, respectively

F_q′

Difference in fluorescence between F_m′ and F′

F_v/F_m

Maximum quantum yield of PSII photochemistry measured in the dark-adapted state

F_p

Peak fluorescence during the initial phase of the Kautsky effect

Rfd

Fluorescence decline ratio in steady-state (F_p − F′)/F′

Φ_PSII

PS II operating efficiency; effective quantum yield of photochemical energy conversion in PSII (F_q′/F_m′)

NPQ

Non-photochemical quenching (F_m/F_m′) – 1

qL

Fraction of PSII centers that are ‘open’ based on the lake model of PSII (F_q′/F_v′)(F₀′/F′)

ETR

Electron transport rate