Abstract: To approach whether there exists winter inhibition in photosynthetic ability of conifersother than Pinus koraiensis, and whether shading can ameliorate it, the photosyntheticability of Pinus koraiensis, Picea koraiensis and Pinus sylvestris var.mongolica seedlingson Changbai Mountain is tested in winter at 20℃.The results show that winter inhibitionand its development in Picea koraiensis and Pinus sylvestris var.mongolica are similar tothose in Pines koraiensis, and shading is very effective to ameliorate photosynthesis inhibition.It is suggested that all the evergreen conifers on Changbai Mountain and similarmountain regions are suffered from photosynthesis inhibition and photooxidation stressduring winter, and CO₂ release (the stronger the solar radiation, the more the CO₂ released) could be considered as a source of CO₂ in the atmosphere.

Key words: Conifer, Shading, Photosynthetic ability, Photosynthesis inhibition, Photooxidation, growth promotion., pot experiment, solid-state fermentation, amino acids, Trichoderma guizhouense