Figure 4.

Curves of each ecotype used to determine the times necessary to induce stomatal opening. The continuous line represents the internal concentration of CO₂ (Ci), and the dotted line is stomatal conductance. The line parallel to the x-axis represents the minimum limit required for open stomata. Lines parallel to the y-axis define the measurement periods. R—measurements with stomatal constraints; nR—measurements with no stomatal constraints. The induction period corresponds to the time interval required to induce stomata opening by applying a concentration of 50 μL CO₂ L⁻¹. Internal concentrations correspond to IRGA measurements with respect to the application of a specific environmental CO₂ concentration, applied according to the time sequences described in Table 1.