The Comparative Study On Physiological Ecology Characteristic Of Three Different Species Of Larch

In this study, we examined all kinds of physiological ecology parameters of three different Larix (L. kaempferi Rupr., L. gmelini Carr., L. olgensis Herry. )during the whole growing season with international advanced portable photosynthetic measuring system. We also measured the effect of elevated CO2 concentration and weak light on their photosynthesis, respiration and transpiration. Results showed that:(1)The photosynthetic ability and water use efficiency of L. kaempferi is larger than the other two species during the whole growing season, it also showed that the L. kaempferi has the largest diurnal assimilation quantity and transpiration efficiency of the three species.(2)The transpiration rate of all the species decreased while the photosynthetic rate and water use efficiency increased under the double CO, concentration and all the parameters of L. kaempferi altered most.(3)The light saturated photosynthetic rate decreased besides L. gmelini, and the transpiration rate decreased in all the species under weak light but L. kaempferi still keep the largest light saturated photosynthetic rate.