Abstract: The diversity and species component of small mammal communities were measured with trap-day method in Alashan region of Inner Mongolia from August to September 1998 and 1999, and in October 2002. The 54 sites were selected in different habitats. The area of the site was 10 hectare in which 400-500 traps were arranged. A total of 866 individuals were captured with 22 606 trap-days during investigation period, and 20 species of small mammals were recorded in the study sites. The results of analysis on diversity of small mammal communities showed that Shannon-Wiener diversity index was 1.186 – 1.589; Pielou evenness index was 0.630 9-0.861 8; Simpson dominance index was 0.234 9 – 0.415 7; Margalef richness index was 0.931 8 -2.020. Based on similarity indices of the communities , the 8 communities could be clustered together at the level of 0.093 5 with systematic clustering , which could be divided into 4 types as follows: Drought2enduring type including community Ⅴand Ⅶ; Arid type including community Ⅰ, Ⅱ, and Ⅲ; Ecotone type that was from farmland to forest including community Ⅵ and Ⅷ; and Forest type including community Ⅳ. The diversity and species component of small mammal communities were determined by the difference of habitats and affected by human activities.

Key words: Small mammal, Community, Diversity, Habitat, Alashan region

摘要： 本文对内蒙古阿拉善地区不同生境中小型兽类群落的物种组成和多样性进行了初步研究。1998 年8～9 月和1999 年8～9 月, 2002 年10 月, 在8 种不同生境类型中共布放54 个样地, 22 606 个有效铗日, 捕获小型兽类标本866 只, 分属2 目6 科, 共20 种。多样性分析结果表明: 8 种不同生境的小型兽类群落Shannon-Wiener 多样性指数在1.186～1.589 之间; Pielou 均匀性指数在0.630 9～0.861 8 之间; Simpson 生态优势度指数在0.234 9～0.415 7 之间; Margalef 丰富度指数在0.931 8～2.020 之间。根据不同生境的小型兽类群落相似性指数聚类结果,可以将8 种生境的小型兽类群落大致划分为4 种类型: 耐旱型(群落Ⅴ和群落Ⅶ)、干旱型(群落Ⅰ、Ⅱ、Ⅲ)、农林交错型(群落Ⅵ和群落Ⅷ) 和森林型(群落Ⅳ) 。生境条件的差异对小型兽类群落物种组成和多样性有一定的限制作用, 而人为干扰有明显影响。