Table I.

Parameters of the photosynthesis model of Farquhar et al. (1980) fitted to the relationships shown in Figure 4 between net CO₂ A and c_i

Values of the parameters Γ_* and K′ (photorespiratory compensation point and effective K_m for Rubisco, respectively) were calculated from expressions given by Farquhar et al. (1980) using values of Rubisco K_m and turnover rates for carboxylation and oxygenation given by de Pury and Farquhar (1997) for 25°C.

Parameter	Symbol	Units	PFD/[O2]
			300/2	1,000/2	300/21	1,000/21
			μEm−2s−1/%
Maximum velocity of carboxylation	Vc,max	μmol m−2 s−1	68 ± 6	90 ± 6	105 ± 38	109 ± 6
Potential electron transport rate	J	μmol e− m−2 s−1	40 ± 1	84 ± 3	39 ± 7	105 ± 5
Mitochondrial respiration rate	Rd	μmol m−2 s−1	0.7 ± 0.1	0.9 ± 0.1	1.0 ± 0.4	1.1 ± 0.1
Intercellular CO2 mole fraction at transition point	ci	μmol mol−1	79 ± 10	145 ± 20	35.9	181 ± 33
Photorespiratory compensation point	Γ*	μmol mol−1	3.4		35.9
Effective Km for carboxylation	K′	μmol mol−1	502.3		811.9