Figure 4

A vs ci response for A. donax.
A′; the supply function of the estimated limitation placed on A by the stomata and leaf boundary layer; A′′ the supply function in the absence of any limitation to diffusion of CO2 from the atmosphere to the site of carboxylation. Observations were measured at 21% oxygen on fully emerged leaves at a I of 1500 μmol m−2 s−1, leaf temperature of 25 °C and VPD of 0.96 (0.01) kPa and gs 0.404 (0.016) mol m−2 s−1. (Values are means and standard errors, for 5 different plants).