Figure 2.
Solution of the model for an oak leaf with gas-exchange, hydraulic, and anatomical data. A, Water potential profile with the vascular plane at z = 0. The horizontal line is the potential drop between the stem and the vascular plane. B, Temperature profile. C, Mole fraction profile. D, Fluxes of energy (red; W m−2) and molecules (dark blue for liquid and light blue for vapor; mmol m−2 s−1) and the percentage of the total transpirational phase change occurring in different regions of a leaf. Conduction (qc; total of both phases) is the dominant mode of absorbed energy dissipation internally within both domains. In the upper domain, a small flux of vapor to the upper epidermis condenses and flows back into the palisade to reevaporate, with a net flux of latent heat to the upper surface.