Photosynthetic Characteristics Research Of Three Native Tree Seedlings In Fujian Province

In this paper, we took Schima superba, Altingia gracilipes and Liquidambar formosana three Fujian native tree seedlings (Schima superba Gardn. et Champ, Liquidambar formosana Hance, Altingia gracilipes Hemsl.) as the object of study, applied LCPRO portable photosynthesis measuring system, portable OS5p modulated chlorophyll fluorometer in the study of photosynthesis of the three species,which provided a scientific basis for the selection and utilization of excellent native tree species of our Province.The main results are as follows:(1) The Pn diurnal variation curve of the three species was a single peak curve.The curve variation trend is close,but the overall diurnal variation of Pn value of Liquidambar formosana was higher than Schima superba and Altingia gracilipes, and Liquidambar formosana had higher photosynthesis. The diurnal variation of transpiration rate curve of the three was a single peak curve, and the rank of the transpiration rate from greater to less was:Liquidambar formosana, Altingia gracilipes and Schima superba. The curves of stomatal conductivity to live of Schima superb and Altingia gracilipes were a single peak curve,but the Liquidambar formosana’s was bimodal curve,and there existed differences between the diurnal variation curves. The diurnal curve trend of the Intercellular CO2concentration and the diurnal change curve of net photosynthetic rate were basically on the contrary, and the tendencies of the diurnal variations of the intercellular CO2concentration of the three species was similar. The three diurnal variation curves of water utilization efficiency were all bimodal curves,and ordered by size were Liquidambar formosana, Schima superba and Altingia gracilipes. The diurnal variation curves of stomatal limitation value of the three species were contrary to the variation curve trend of the Intercellular CO2concentration.(2) The Pn of the three species was related to the external environment factors and internal factors. The Pn of the three species and photosynthetic active radiation PAR were significant correlation.The Pn of Schima superba and its Tr, Gs were positively correlated, and was significantly negatively correlated with Ci.The Pn and Tr of Tr Altingia gracilipes had significant correlation, was significantly negatively correlated with Ci, and had no significant correlation with Gs. The Pn and Tr of Liquidambar formosana was much significantly related to Gs,and was significantly negatively correlated with Ci.(3) The LCP of Liquidambar formosana was lower than that of Altingia gracilipes and Schima superba, and its ability of using the weak light was stronger than that of Schima superba and Altingia gracilipes.The LSP of Altingia gracilipes was higher than that of Liquidambar formosana and Schima superba,and its ability of using the strong light was stronger than that of Liquidambar formosana and Schima superba. The light saturation point of Schima superba, Altingia gracilipes and Liquidambar formosana was high,and they were heliophilous species. Compared with Schima superba, Altingia gracilipes, Liquidambar formosana had higher AQY, larger MaxPn and lower Rd,and it had stronger fast-growing ability.(4)The CO2compensation point of Liquidambar formosana was the highest, followed by Schima superba, and Altingia gracilipes was the lowest,which showed that the ability of Liquidambar formosana to use the CO2concentration was weaker and that of Altingia gracilipes was stronger.The CO2saturation point of Liquidambar formosana was the highest, followed by Altingia gracilipes, and Schima superba is the the lowest, which showed that the ability of Liquidambar formosana to use the CO2concentration was stronger and that of Schima superba was weaker.(5)There were obvious differences in the Fv/Fm diurnal variation trend of the three species,and Liquidambar formosana’s variation was minimal,the Fv/Fm curve of Altingia gracilipes fluctuated greatly. The diurnal variation of the three species gave a typical curve with double peaks. The diurnal variation of Fm displayed a shape of "V",and the average value of Altingia gracilipes was higher than that of Liquidambar formosana and Schima superba. Liquidambar formosana and Altingia gracilipes had higher NPQ value and varied within a small range, but the NPQ value of Schima superba varied within a bigger range.The qP value of Altingia gracilipes was greater than the other two,which showed that Altingia gracilipes could adapt to more strong specular environment and had better protection mechanism for highlights.