A, Electron transport rate (J) at different levels of incident PFD for leaves at 1-, 1.5-, 2-, 2.5-, and 3-m height. Error bars indicate 1 sd. B, Light-saturated photosynthetic assimilation rates at different leaf intercellular CO2 concentrations for leaves at 1-, 1.5-, 2-, 2.5-, and 3-m height. Measurements were taken at 1,600 μmol m−2 s−1 PFD and 22°C, and vapor pressure deficit was kept below 1 kPa.