<正>利用751分光光度计测定鹅掌楸树冠阴阳面和上下冠层4个方位在不同生长季节叶绿素a、叶绿素b和叶绿素总量;应用LI 6400红外气体分析仪测定鹅掌楸不同部位不同生长季节中净光合速率日变化及季节变化。采用多元统计分析,得出净光合速率与光强、温度和相对湿度等环境因子之间的相关关系,找出不同条件下影响净光合速率的主导因子,分析不同方位及冠层对净光合速率的影响。初步了解了鹅掌楸的光合性能。

Liriodendron chinense is a common deciduous tree.Its net photosynthetic rate(Pn),gross chlorophyll content,chlorophyll a and b content in different growth seasons and different positions within tree crown were determined.The correlativity between net photosynthetic rate and environmental factors and the influence of positions within tree crown on Pn were analyzed. For Liriodendron chinense,the gross chlorophyll content showed flourishing stage>final stage>initial stage,which accorded with the seasonal change of the net photosynthetic rate.And photons density was the major influencing factor of Pn in initial stage and final stage of growth season,while temperature was the major influencing factor in flourishing stage.The daily course of Pn was single peaked in initial stage and final stage,unobvious double peaked in flourishing stage.The influence of positions within tree crown on net photosynthetic rate was not notable in different growth stages.