Figure 10.

Changes in the distribution of evaporation across tissues resulting from changes in g_s to water vapor. PPFD = 1,500 μmol m⁻² s⁻¹, T_air = 25°C, and w_air = 15 mmol mol⁻¹. Abbreviations are as in Figure 2. Negative values for evaporation mean that net condensation occurred at the tissue in question. At very low g_s, AVT toward the lower epidermis driven by the T gradient between warmer palisade mesophyll and cooler lower epidermis exceeds the net transpirational flow of water out of the lower leaf surface; mass balance requires condensation of the excess water at the lower epidermis and liquid phase flow back up to the mesophyll. All anatomical parameters were set at their all-species average values (Supplemental Table S2).