Abstract: Physiological ecology parameters of photosynthesis and water of two-year seedling obtained from hardwood cutting of Larix olgensis from ten provenances were measured in artificial climate romm. The result showed that, some rules can be found though physiological ecology parameters of Larix olgensis from different provenances varied greatly. Total photosynthesis rate> maximal net photosynthesis rate> net photosynthesis rate> net photosynthesis rate at semi-light saturation point> light respiration rate> respiration rate among all provenances, but occasional exception existed. Among all parameters, respiration rate varied least, light respiration rate varied greatly, and total photosynthesis rate varied most. The change tendency of all parameters among the provenances is in accordance with net photosynthesis rate, i. e., the other parameters varied greatly while net photosynthesis rate varied greatly and the other parameters varied less while net photosynthesis rate varied less in one provenance. Relative hight respiration rate among the provenances varied greatly, and CO₂ released amounted to one third of CO₂ fixed. Light compensation point, light saturation point and semi-light saturation among all provenances varied greatly. The more variation of water utilization efficiency resulted from net photosynthesis rate and related slightly to transpiration rate. Percentage of net photosynthesis to total photosynthesis, respiration efficiency, CO₂ compensation point, transpiration rate and water potential varied slightly among all provenances.

Key words: Larix olgensis Henry, Provenance, Physiological ecology