中文摘要：

为了解内蒙古高原东南缘森林草原交错带土壤动物群落特征,对这一地区不同植被地带中的土壤动物进行了调查。共捕获土壤动物53 722只,隶属于6门11纲27目（类）。大型土壤动物优势类群为鞘翅目、柄眼目、小蚓类、弹尾目和膜翅目,中小型土壤动物优势类群为弹尾目和蜱螨目,湿生土壤动物优势类群为小杆目。研究表明,由森林带向草原带过渡,土壤动物的个体数量和类群数呈减少趋势,森林带和森林-草甸区具有最高的类群数,交错带草甸-草原区和森林带具有最高的个体数量;不同植被地带土壤动物优势类群的组成与数量存在差异;DG指数、J指数和C指数差异显著。不同植被地带土壤动物个体数量和类群数具有明显的表聚性。夏季各个植被地带土壤动物具有最高的类群数,秋季森林带和森林-草甸带具有最高的个体数量;DG指数在不同植被地带中（森林带除外）存在显著的季节差异;不同季节土壤动物优势类群的组成与数量存在差异。

英文摘要：

To investigate the characteristics of soil fauna community structure in forest-steppe ecotone on South- eastern Inner Mongolia Plateau, the soil fauna communities from 4 different vegetation zones were investiga- ted. A total of 53 722 soil fauna were collected and classified into 6 phyla, 11 classes, and 27 orders, respec tively. The dominant groups were Coleoptera, Stylommatophora, Microdrile oligochaetes, Collembola and Hymenoptera among macro-soil-fauna; whereas the dominant groups were Collembola and Acarina among soil meso-and micro-fauna; and the dominant group was Rhabditidia among soil animals of wet type. The individual numbers and the group numbers were declining with the transition from the forest zone to the steppe zone, a mong which forest zone and forest-meadow area had the highest number of groups as well as the meadow steppe area in the ecotone and forest zone had the highest number of individuals. Besides, there are differences in numbers and compositions of the dominant groups of soil animal in different vegetation zones and significant difference especially in density-group index （DG）, Pielou evenness index （J） and Simpson dominance index （C）. The individual numbers and group numbers of soil animals in different vegetation zones showed clear sur face assembly. The maximum of the group numbers appeared in summer in all the vegetation zones, but the maximum of the individual numbers in forest-meadow zone and forest zone appeared in autumn. There were not only significant seasonal differences in density-group index in different vegetation zones （except in forest zone） but also differences in the composition and abundance of the dominant groups of soil animals in different seasons.