Figure 1.

Example of the effect of irradiance on net CO₂ exchange (μmol CO₂ m⁻² s⁻¹) versus p_i of a single leaf at three temperatures: 6°C (A), 15°C (B), and 25°C (C). Measurements were also conducted at 10°C, 20°C, and 30°C (not shown). The symbols represent the irradiances under which each set of measurements was made (in μmol photons m⁻² s⁻¹). Lines represent the linear regressions at each irradiance.