Acclimation of photosynthesis and growth to different growth light conditions for seedlings of Cyclobalanopsis glaucoides

The response of net photosynthetic rate (Pn) to photon flux density (PFD) and the growth condition for seedlings of Cyclobalanopsis glaucoides grown under three irradiance levels(80%,20% and 2% full-light) were examined in this paper. The results showed that,there was no significant differences of the light saturation point(LSP) and the Max. net photosynthetic rate among three irradiance levels,the light compensation point (LCP) in seedlings grown under 20% and 2% full-light were decreased significantly compared with 80%. The LSP were all about 400～450 μmol·m-2·s-1 and the LCP were bout 6～10 μmol·m-2·s-1 in seedlings grown in three light levels,exhibited a characteristic of shade plant. Seedlings of C.glaucoides had a strong ability of shade-tolerance,but this adaptability is at the cost of its’reduction of growth rate and dry mass accumulation. The leaf mass per unit area (LMA) decreased and the chlorophyll content increased significantly in seedlings grown under 2% full-light,showed a great capability to taking use of high irradiance,they could grow quickly when canopy formed.