A Study on Photosynthesis of Toona sinensis and the Effect of Environmental Factors

The photosynthesis of Toona sinensis and the effect of environmental factors were studied. The results show that the curve of seasonal variation of T. sinensis shows two peaks, which appear in June and August. The diurnal net photosynthesis rate varies with double peak curve. The first occurs at 9:30 and the second at 16:30 respectively. There is a significant midday depression. Non stomatal factors like the ability of leaf are the main causes of the pause. The light compensation point and light saturation point of T. sinensis leaves are 53.9 μmol.m-2.s-1 and 1 100 μmol.m-2.s-1 respectively. The optimal temperature for photosynthesis of T. sinensis leaves is 35.8 ℃.