Figure 2.

Pooled data (n = 5) showing the response of transpiration (proportional to stomatal conductance under the controlled vapor pressure growth regime) to increasingly negative Ψ_leaf as soil dried during the drought treatment. Regressions are sigmoidal functions in each case, and these regression functions were used to define the stomatal dependence upon Ψ_leaf to evaluate the degree of hydraulic limitation during drought recovery (see Fig. 5A).