Abstract: By using CI-301PS portable photosynthesis system, this paper studied the photosynthetic characteristics of Kingdonia uniflora under natural condition. The results showed that the diurnal change of net photosynthetic rate (P_n) presented a bimodal pattern,i. e. , reached the maximum at 13:30 and 16:30, and had a midday depression. The diurnal variation patterns of leaf transpiration rate (T_r) and water use efficiency (WUE) were also bimodal. There were significant polynomial regressive relationships between P_n and photosynthetic active radiation (PAR), T_r and stomatal conductance (G_s) (R²=0.2082, 0.2016 and 0.0582, respectively,n=129, P<0.05), while no significant correlation was observed between P_n and air temperature (T_a) (P>0.05). The light compensation point (LCP) was 14.93 μmol·m^-2·s^-1, and the light saturation point (LSP) was 215.76 μmol·m^-2·s^-1, suggesting that K. uniflora could only adapt to restricted light condition.

Key words: Sub-alpine forest, Spatial pattern, Restoration, Topography, Regeneration