中文摘要：

【目的】分析桂林喀斯特石山植物叶片光合色素指标的数量特征,运用多元统计方法从光合色素的角度探索出主要耐荫性指标,并对不同植物进行耐荫性程度分类,探讨不同植物适应喀斯特石山生境所表现出的光合色素生理特征,为修复退化喀斯特石山生境提供相应的理论依据。【方法】选择桂林喀斯特石山生境中常见的50种植物为研究对象,分别测定叶片叶绿素a（Chl a）、叶绿素b（Chl b）、类胡萝卜素（Car）、总叶绿素Chl（a＋b）含量和Chl a/b比值5个光合色素指标值;采用单因素方差分析及多重比较检验不同植物光合色素指标值的差异显著性;采用Pearson相关性分析法对不同光合色素指标值进行相关性检验;利用主成分分析法找出植物叶片光合色素指标中的主要变量;基于50种植物耐荫性主成分排序,采用有序样本分割法对50种植物进行耐荫性程度划分。【结果】50种植物叶片Chl a,Chl b,Car,Chl（a＋b）和Chl a/b比值的平均值分别为2.89 mg·dm^-2,1.19 mg·dm^-2,0.59 mg·dm^-2,4.07 mg·dm^-2和2.47;50种植物叶片光合色素5个指标值分别均存在极显著差异;Chl a,Chl b,Car,Chl（a＋b）之间均呈极显著的正相关,Chl a/b比值与Chl b之间呈极显著的负相关,与Chl a之间相关性不显著;表征桂林喀斯特石山生境中50种植物叶片光合色素的主要指标为叶绿素含量[chl a,chl b,chl（a＋b）],其次为Chl a/b比值;50种植物划分为3种类型：（I）阴生植物、（II）植物兼有阴生和阳生的特性、（III）植物具有阳生性或者中生性特征。【结论】基于叶片叶绿素含量和Chl a/b比值判断植物耐荫性与实际情况总体较吻合,这2个指标是反映植物耐荫性的重要指标,研究结果为该地区的植被恢复与重建过程中的物种选择提供参考。

英文摘要：

【Objective 】 In this study,quantitative characteristics of leaf photosynthetic pigments indexes of plant species in Karst rocky mountains in Guilin were analyzed to dig up the main shade tolerance indicators by using multivariate statistical method. Furthermore,the different plant species were classified based on the degree of shade tolerance to investigate the physiological characteristics of photosynthetic pigments by which the different plant species adapt their sites in the Karst rocky mountains. Thus,the study would provide a corresponding theoretical basis in restoring the degraded Karst rocky mountain habitat. 【Method】A total of 50 common plant species growing in Karst rocky mountain of Guilin were selected to measure the leaf photosynthetic pigment indicators, including chlorophyll a（ Chl a）,chlorophyll b（ Chl b）,Carotenoid（ Car）,Chl（ a ＋ b） contents and Chl a / b. One- way ANOVA and post hoc Duncan test were used to test the significance of difference in each photosynthetic pigment indicator among the 50 plant species.Pearson correlation analysis was used to test the correlation between one photosynthetic pigment indicator and another.Principal component analysis（ PCA） was used to find the main variables among the photosynthetic pigment indicators.The optimal partition of ordered sample method was used to divide the degree of shade tolerance among the 50 plant species based on the PCA ordination of shade tolerance. 【Result】The average values of Chl a,Chl b,Car,Chl（ a ＋ b） and Chl a / b of the 50 plant species were 2. 89 mg·dm^-2,1. 19 mg·dm^-2,0. 59 mg·dm^-2,4. 07 mg·dm^-2,and 2. 47,respectively. There were significant differences in all the 5 photosynthetic pigment indicators among the 50 plant species.There were significantly positive correlations among Chl a,Chl b,Car and Chl（ a ＋ b）,and a negative correlation between Chl a / b and Chl b,and no significant correlation between Chl a / b and Chl a. The main differences of photosynthetic pigment indicator