Fig. 7. Three dimensional plot of stomatal conductance (g) measured at a photosynthetic photon flux density (PFD) of 1500 µmoles (photons) m^–2 s^–1 vs. leaf minus air temperature differential (T_L – T_a) and vapor pressure deficit (VPD_L). Equation for the fitted plane is y = 1.08 – 0.09(T_L – T_a) – 0.26(VPD_L), with R² = 0.80, S_y.x = 0.17, and n = 166.