The rodents were investigated with trap-day method in Alashan Desert of Inner Mongolia from August to September 1998 and 1999. Sixty-five sites were selected according to conditions of vegetation, landform, topography and soil. The area of the site was 10 ha in which 400-500 traps were arranged. There were 1019 samples captured with 31 469 effective trap-days in all sites. The results showed that Meriones meridianus was a typical dominant species and Euchoreutes naso was one of representative rodents in Alashan Desert. The Alashan Desert was a new distribution region of Salpingotus crassicauda in China. Therefore, geographical distribution of the three rodents was analyzed with Map-info Professional 615 software of GIS (Geographical Information System). The results showed that the distribution maps of the three rodents, which were obtained on the basis of GIS, not only told the infor-mation of prophetical distribution of the three rodents in Alashan Desert, but also reported information of the rodents' distribution affected by habitat change, which can not be obtained by traditional site-distribution ways. This result can be used as scientific foundation for perfecting research design and monitoring harmful rodents in future.

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，22606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0.6309～0.8618 之间；Simpson生态优势度指数在0.2349～0.4157之间；Margalef丰富度指数在0.9318～2.020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。

1991年～1993年在内蒙古大兴安岭库都尔林业局岩山林场野外设置8块样地和1块标志流放区，对莫氏田鼠（Microtusmaximowiczii）的种群数量动态、繁殖和巢区进行了研究。结果表明1991年为当地莫氏田鼠的数量高峰年，其种群数量最高月7、8月的捕获率在8种生境中平均为13.34%和21.89%，1992年为其数量低峰年，7月各个样方平均捕获率仅为1142%，与高峰年相差10倍～17倍。莫氏田鼠的最适生境沼泽地和塔头甸子3年平均捕获率分别为5.89%和3.9%，麦田中莫氏田鼠的数量也很高，3年的捕获率分别达到13.85%、0.78%和30%。莫氏田鼠的繁殖高峰在6月、7月，8月、9月几乎不进行繁殖，3年平均仔数为7.28。莫氏田鼠的巢区面积越冬雄性达1874.46±539.31m2，越冬雌性达1658.54±499.98m2。

本文采用主成分分析法，对内蒙古大兴安岭地区莫氏田鼠的体重、体长、尾长、后足长、颅全长、颅基长、上齿列长、齿隙长、听泡长、听泡宽、眶间宽、鼻骨长、颧宽、后头宽、下齿列长、后头高16项指标测量并进行二维排序。结果表明：在莫氏田鼠的年龄鉴定和划分中，用体重和体长加以头骨的颅基长和颅全长其准确率可达95%以上。

根据库布其沙漠及其毗邻地区生境和鼠类分布的差异，应用系统聚类法，将该地区的鼠类划分为5个群落：（1）沙漠鼠类群落；（2）半荒漠区沙地鼠类群落；（3）荒漠鼠类群落；（4）荒漠化草原鼠类群落；（5）干草原鼠类群落。5个群落可聚为3个群落组。（1）沙地群落组；（2）半荒漠和荒漠群落组；（3）干草原群落组。同时对鼠类群落的多样性、均匀度等进行了初步分析。