叶片光合能力直接决定着植物生产力的高低,它既受外界环境条件的影响,也受叶片内部因素的制约。本文以“日”为单位对叶龄进行度量,从爆芽日开始,对蒙古栎光合作用参数随叶龄的变化及其与叶片功能性状的关系进行了分析。结果如下:(1)蒙古栎叶片生长季初期(爆芽后3日内)其呼吸速率大于光合速率,净光合速率为负值;生长季中期,光合参数P_(max)(最大净光合速率)、J_(max)(CO2饱和时最大净光合速率)、V_(cmax)(最大Rubisco催化反应速率)的变化主要受环境因子(降雨、土壤含水率)的影响。(2)整个生长季初期,光合参数与叶绿素含量及叶面积呈极显著正相关(P<0.01);生长季初期爆芽阶段光合参数与比叶重呈负相关,生长季初期展叶阶段光合参数与比叶重呈正相关,在生长季初期叶片完全展开后,光合参数与比叶重呈负相关;生长季中期,所有的光合参数与叶片功能性状无显著相关性;生长季后期,光合参数与叶片功能性状均呈显著正相关(P<0.05)。建议今后研究中,考虑根据叶片的生长过程分阶段探讨其光合能力及其生理生化影响机制,以增加森林生态系统碳收支估算的准确性。 Leaf photosynthetic capacity directly determines the level of plant productivity, which is not only affected by the external environmental conditions, but also by the leaves of internal constraints. In this paper, the leaf age was measured on the basis of “Japan ”. From the date of blasting day, the relationship between the parameters of photosynthesis and the leaf functional traits of Quercus mongolica was analyzed. The results were as follows: (1) The photosynthetic parameters P max (net photosynthetic rate), photosynthetic rate (Pn), photosynthetic rate The changes of J max (maximum net photosynthetic rate under CO2 saturation) and V cmax (maximum Rubisco catalytic reaction rate) are mainly affected by environmental factors (rainfall and soil moisture content). (2) At the beginning of the growing season, the photosynthetic parameters were significantly and positively correlated with chlorophyll content and leaf area (P <0.01). The photosynthesis parameters at the germination stage were negatively correlated with specific leaf weight at the early growing season, There was a positive correlation between leaf photosynthetic parameters and specific leaf weight. The photosynthetic parameters were negatively correlated with specific leaf weight at the beginning of the growing season. And leaf functional traits were significantly and positively correlated (P <0.05). It is suggested that in the future study, the mechanism of photosynthetic capacity and its physiological and biochemical effects should be explored in stages according to the growth process of the leaves in order to increase the accuracy of estimating the carbon budget of forest ecosystems.