中文摘要：

通过对重庆四面山杉木（Cunninghamia lanceolata）林样地的调查，运用丰富度指数、Shannon-Wiener多样性指数、Simpson多样性指数和Pielou均匀度指数，分析了该地区杉木群落物种多样性特征，将该地区现存杉木群落划分为2个群系组（杉木林和杉木针阔混交林），8个群系，10个群丛。结果表明，杉木群落可分为乔木层、灌木层和草本层。在杉木林群系组中，丰富度指数、多样性指数和均匀度指数均表现为灌木层〉草本层〉乔木层。在杉木针阔混交林群系组中，丰富度指数表现为灌木层〉乔木层〉草本层；多样性指数多数表现为灌木层〉乔木层〉草本层；均匀度指数变化较为复杂，没有统一规律。杉木群落各层的丰富度指数随海拔高度的升高总体上呈下降趋势。群落各层的多样性指数随海拔高度的升高在特定区间内表现出一定规律性：在海拔1180m以下低海拔区域，随海拔高度的升高呈下降趋势；在海拔1180～1351m范围内，随海拔高度的升高呈波动状态；而在海拔1351m以上高海拔区域，又呈下降趋势。群落各层的均匀度指数随海拔梯度变化较为复杂，未表现出明显规律。

英文摘要：

Chinese fir （ Cunninghamia lanceolata） plantation is one of the main vegetations in the Simian Mountain of Chongqing. Chinese fir is also one of the main species of trees aftbresting the area. Based on the data from the survey of a typical Chinese fir plantation in the area, species diversity of the Chinese fir community was analyzed using richness index, Shannon-Wiener index, Simpson index and Pielou evenness index. The existing Chinese fir community in the area can be divided into 2 formation groups （ Chinese fir plantation and mixed Chinese fir-broadleaved forest）, 8 plant formations and 10 associations. Results show that the Chinese fir community is formed of arbor tree, shrubbery and herb layers. In the Chinese fir plantation, the three layers demonstrate a declining trend in richness, diversity and evenness indices, i.e. shrub layer〉herb layer〉arbor layer, while in Chinese fir mixed wood, the trend in richness index goes as shrub layer〉arbor layer〉herb layer; and in diversity index as shrub layer〉arbor layer〉herb layer; and however, the trend in evenness index is rather complicated without any of uniform law. With the rise in altitude the richness index of the Chinese fir community regardless of layers declines as a whole while their diversity indexes increase and display a certain law within a given region, that is, declining with the rising altitude where below 1 180 m, but fluctuating within the range between 1 180 m and 1 351 m, and declining again where above 1 351 In. The change in evenness index with all the layers is rather complicated and has no clear rule.