基于植物能量功能群的草原植物光合作用研究

The photosynthesis of steppe plant based on the Energy Plant Functional Groups

植物能量功能群是依植物能量属性进行的植物功能类群划分,植物通过光合作用将光能转变成化学能,蓄积在植物体内,为了探究不同的能量功能群是否会表现出光合作用特征的差异,用LI-6400型便携式全自动光合测定仪,在内蒙古锡林郭勒典型草原区,于7月底至8月初的植物生长旺盛期,测量了羊草(Leymus chinensis)、糙隐子草(Cleistogenes squarrosa)、星毛委陵菜(Potentilla acaulis)等植物的净光合速率、气孔导度及蒸腾速率的日进程,比较了不同能量功能群及其各自代表植物的光合日进程曲线。结果发现,所研究植物的净光合速率日进程曲线都是双峰曲线,有明显"午休"现象。高能值植物功能群净光合速率小于低能值植物,气孔导度与蒸腾速率也小于低能值植物,这与低能值植物旺盛的生命活动以及采取的繁殖策略相关。

Energy Plant Functional Groups（Energy PFGs） is a kind of functional classification method based on plant energy properties.The sun energy was transformed into chemical energy and stored in plants by plant photosynthesis.A field survey was conducted to determine the relationships between Energy PFGs and plant photosynthetic characteristics by measuring the leaf photosynthetic parameters of Leymus chinensis、Cleistogenes squarrosa、Potentilla acaulis using a LI-6400 Portable Photosynthesis System in Typical Steppe of Xilingol from the end of July to mid August.The photosynthetic included the diurnal variations of net photosynthetic rate（Pn）,stomatal conductance（Sc）,transpiration rate（Tr）.This study showed that the diurnal variation of Pn of all the plants took on ＂double-peak＂ curve with remarkable midday depression,peaking at 12 and 16 o＇clock and depressing at 12 to 14 o＇clock,respectively.The Pn,Sc and Tr of high-energy PFGs was lower than that of low-energy PFGs,and this phenomenon was related to vigorous life activities and reproduction strategy of low-energy PFGs.