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应用Li-6400P便携式光合测定系统于生长季(8月)测定了4种模拟光环境(100%、60%、30%和15%自然光强,分别记为FI、II、LI和WI)和3个实际光环境(林窗、林下和林缘,分别记为G、U和E)下3个苗龄红松(Pinus koraiensis)针叶气体交换参数和净光合速率(Pn)的日变化,以及单位叶面积叶绿素(Chl)含量和比叶质量(LMA)的变化。结果表明:3年和5年生红松在II和LI处理间的Pn基本一致,且均高于FI的Pn;7年生红松在FI处理下的Pn高于其他处理的Pn,各处理的Pn峰值均出现在13:00。3年和5年生红松在LI处理下的最大光合速率(Amax)和暗呼吸速率(Rd)均高于全光FI处理。随光强降低,LMA呈下降趋势,说明红松通过改变LMA的方式适应光环境的变化。3年和5年生红松II处理与G处理间的光合生理指标差异不显著(P>0.05),LI和WI处理与E处理间同样如此,说明光环境模拟很好地反映了实际的光环境。通过对红松针叶生理生态指标的可塑性分析,得出3种不同苗龄红松可塑性的大小顺序为3年>5年>7年。表明随树龄增大,红松的需光性增加;3年和5年生红松在全光30%～60%条件下生长较好,7年生红松则是在全光下生长最好。
Four simulated light environments (100%, 60%, 30% and 15% of natural light intensity, denoted FI, II, LI and WI, respectively) were measured during the growing season (August) using the Li-6400P portable photosynthesis system Diurnal variations of gas exchange parameters and net photosynthetic rate (Pn) of three seedlings of Pinus koraiensis in three actual light environments (Gap, undergrowth and forest margin, denoted as G, U and E) , And the changes of leaf chlorophyll (Chl) and specific leaf mass (LMA). The results showed that the Pn of 3-year and 5-year-old Pinus koraiensis was the same between the treatments of II and LI, and both were higher than that of FI. The Pn of 7-year-old Pinus koraiensis under FI was higher than that of other treatments, Pn The peak appeared at 13:00. The maximal photosynthetic rate (Amax) and dark respiration rate (Rd) of 3-year and 5-year-old Pinus koraiensis under LI treatment were higher than that of the all-light FI treatment. With the decrease of light intensity, LMA showed a downward trend, indicating that Korean pine can adapt to the changes of light environment by changing the way of LMA. There was no significant difference in the photosynthetic physiological indices between the 3-year and 5-year-old Korean pine and G treatments (P> 0.05). The same was observed between the LI and WI treatments and the E treatment, indicating that the light environment simulation reflected the actual light environment . Through the plasticity analysis of the physiological and ecological indexes of Korean pine needles, the order of the plasticity of Korean pine at 3 different ages was 3 years> 5 years> 7 years. The results showed that with the increase of tree age, the light requirement of Pinus koraiensis increased. The Pinus koraiensis grew well at 30% ~ 60% of the total light for 3 years and 5 years, while the Pinus koraiensis grew best under all light.