Abstract:

Abstract: We used the 3 year seedlings of Larix principis rupprechtii and Picea meyeri to investigate their growth and physiological changes, and survival differences and other functional traits in response to the four light regimes (0%, 55%, 75% or 95% shade) and five planting densities. After a whole growing season, the relative root collar diameter growth (RCDG) of larch seedlings was significantly increased under deep shade (95%), while the survival rates were also significantly increased under moderate shade (55% and 75%). The relative growth rate (HG) and chlorophyll content of spruce seedlings significantly increased with decreasing light, but the survival rates were not affected at all. Under different planting densities, the larch seedlings did not show significant difference in their growth and physiological performances, but the survival rates under moderate planting densities were significantly higher than those under higher and lower planting densities. Furthermore, the HG and chlorophyll content of spruce seedlings mixed with larch were significantly higher than those of pure spruce seedlings, while no difference in survival rates was observed between of them. These results suggest that moderate shade and moderate planting densities can improve the growth performance of larch seedlings to some extent and significantly increase their survival to warrant the larch successfully established, while moderate shade and mixing plantation are favorable for the growth of spruce seedlings.

Key words: Key words: Larix principis rupprechtii, Picea meyeri, light availability, planting density, growth and ecological response, survival rate