Abstract: Correlation analysis and RDA ranking method were used to analyze the characteristics of plant community diversity and environmental factors of adaptive region of the Gentianella turkestanorum in the middle section of the southern slope of the Tianshan Mountains. The results showed that 87 species were recorded in 24 plots of the suitable plant communities of Gentianella turkestanorum,belonging to 54 genera of 20 families. The plant functional composition and species diversity were different among 10 plant communities. The widely distributed species are Asteraceae,Gramineae,Leguminosae and Rosaceae. Among the species diversity indices of each community,the Simpson diversity index was the highest,and the diversity index of each species varied greatly. The correlation analysis between community species diversity index and population characteristics and environmental factors showed that the Margalef richness index of community species was significantly affected by the soil total nitrogen content and total phosphorus content. The Simpson diversity index of community species was significantly affected by altitude and soil total salt. The important value and populations of Gentianella turkestanorum in the community were remarkably affected by pH;the population of Gentianella turkestanorum height in the community was significantly affected by the available K,the elevation and total soil salt. RDA analysis further showed that TN,TP,AK,pH and altitude were the main environmental factors affecting community species diversity.

Key words: Species diversity, Plant communities, Soil properties, Gentianella turkestanorum(Gand.) Holub, Redundancy analysis

摘要： 采用相关分析和RDA排序法分析了天山南坡中段库车山区新疆假龙胆适生地植物群落多样性特征及其环境影响因子。结果表明，在新疆假龙胆适生地植物群落的24个样地中，共记录到物种87种，隶属于20科54属；共有10种植物群落类型，其结构组成及物种多样性组成是不同的，分布较广的物种为菊科、禾本科、豆科和蔷薇科。各群落物种多样性指数中，Simpson指数最高，各样地间多样性指数测值变幅较大。群落物种多样性指数及种群数量特征与环境因子的相关性分析表明，群落物种Margalef丰富度指数显著受土壤全N、全P的影响；群落物种Simpson多样性指数显著受海拔、土壤总盐的影响；群落中新疆假龙胆的重要值及其种群数量受pH的显著影响；群落中新疆假龙胆种群高度显著受有效K、海拔和土壤总盐的影响。RDA分析表明，全N、全P、有效K、pH、海拔是影响群落物种多样性的主要环境因素。

关键词: 物种多样性, 植物群落, 土壤特性, 新疆假龙胆, RDA分析