藏东南色季拉山蚂蚁群落的物种组成及多样性

Species Composition and Diversity of Ant Communities in Mount Sejila in Southeastern Tibet

采用样地调查法研究了藏东南色季拉山海拔2 023～4 548 m蚂蚁群落的物种组成和多样性规律。共采集蚂蚁16212头,隶属于3亚科12属24种,其中包括17个已知种,7个待定种。樱花立毛蚁(Paratrechinasakurae(Ito))和尼特纳大头蚁(Pheidole nietneri Emery)是色季拉山的优势种。色季拉山东西坡不同海拔蚂蚁群落的物种数目1～11种(平均值4.1种),个体密度0.4～1272.6头/m2(平均值202.7头/m2),物种多样性指数0～1.4156(平均值0.5346),均匀度指数0.0833～0.9940(平均值0.5362),优势度指数0.3327～1.0000(平均值0.712 7)。蚂蚁群落的物种数目、个体密度、多样性指数随着海拔升高而依次降低,这一现象符合蚂蚁多样性在山地环境的分布主要受热量因子(气温)制约的规律。蚂蚁群落的优势度指数和均匀度指数无规律性,二者之间存在明显负相关性,主要受森林结构和生境因子影响。在同一坡面上,蚂蚁群落之间的相似性随着海拔上升而增加,主要受植被类型的多样性制约。东西坡蚂蚁群落的相似性随着海拔升高而增加,主要受距离因子制约。

A survey was conducted to study the species composition and diversity rule of ant communities in Mount Sejila in southeastern Tibet at altitudes of 2 023 m to 4 580 above the ground by sample plot method. A total of 16 212 ant individuals of 24 species, belonging to 12 genera and 3 subfamilies, were collected, which included 17 known species and 7 unidentified species. Paratrechina sakurae （Ito） and Pheidole nietneri Emery are dominant species in Mount Sejila. The main indexes of ant communities in each plot on both west and east slopes at different altitudes were obtained as number of species 1 - 11 （ average 4. 1 ）, individual density 0. 4-1 272.6 heads per square meter （202.7）, Shannon-Wiener index 0-1. 415 6 （0. 534 6）, evenness index 0.083 3-0.994 0 （0. 536 2）, and dominant index 0. 332 7-1. 000 0 （0. 712 7）. Number of species, individual density, and Shannon-Wiener index decrease with increasing altitude, which is in accord with the dis- tribution law that the ant diversity in mountainous environment is mainly controlled by thermal factor （air temperature）. There is no obvious regularity in evenness index and dominant index of the ant communities, but a distinct negative correlation was observed between the two indexes. The evenness index and dominant index of the ant communities are mainly influenced by forest structure and habitat factors. On the same slope, the similarity between the ant communities increases with increasing altitude, which is mainly restricted by diversity of vegetation types. However, the similarity between the ant communities on the east-west slope also increases with increasing altitude, which is mainly restrained by distance factor.