Figure 3. Integrated gas exchange of the whole leaves and the ratio of integrated parameters for the adaxial and abaxial surfaces.
(a–i) The integrated net photosynthetic rate (Pn, a–c), transpiration rate (E, d–f) and water use efficiency (WUE; g–i) of Platanus orientalis L. (a,d,g), Melia azedarach L. (b,e,h) and Solanum lycopersicum L. (c,f,i) under constant irradiation (1,000 μmol m−2 s−1) or simulated ad-ab-alt irradiation. (j–l) The ratio of the integrated parameter of the adaxial and abaxial surfaces. To simulate alternant irradiation, the adaxial or abaxial surface was irradiated under fluctuating light. The irradiation was switched between high and low light every 4 min, 2 min or 1 min. To calculate the integrated gas exchange under simulated ad-ab-alt irradiation, the values measured during the high light periods of fluctuating light under abaxial and adaxial surface irradiation were summed. The integrated gas exchange under constant irradiation was 100%, whereas the integrated values under simulated ad-ab-alt irradiation were expressed as a percentage of the former value. The reported values are the mean (±SE), n = 5.