where Vcmax is the maximum rate of carboxylation (µmol CO2 m−2 s−1), O is the partial atmospheric pressure of O2 (mmol mol−1),Γ* is the CO2 compensation point in the absence of mitochondrial respiration, Rday is mitochondrial respiration in the light (µmol CO2 m−2 s−1), Ci is the intercellular concentration of CO2 (µmol mol−1), Cc is the chloroplastic concentration of CO2 (µmol mol−1), Kc (µmol mol−1) and Ko (mmol mol−1) are the Michaelis–Menten constants of Rubisco for CO2 and O2, respectively, J is the rate of electron transport (µmol CO2 m−2 s−1), Jmax is the maximum rate of electron transport (µmol CO2 m−2 s−1), Q is the incident PAR (µmol m−2 s−1), α is the quantum efficiency, which represents the initial slope of the photosynthetic light response curve, and gm is mesophyll conductance (mol CO2 m−2 s−1).