Abstract: During 1993 ～1995 we conducted an experiment in which we removed the dominant species of rodent, Rattus nitidus, from a 2 hm² plot in theWestern Sichuan Plain and set a 1.5hm² control plotin the same habitat. The experiment evaluates the extent to which the dominant species influences other rodent populations. Monito ring with live traps and statistical analyzing with paired t-testing of difference between the experimental and control plots revealed that: the removal of R.nitidus (1) resulted in increases of population density (R.nevigicus and R. flevipectus) and biomass (R.confucians) during a certain year o r overall study period;(2) induced significant increases in the number of species and Shannon indexes of species diversity during 1995 and overall study period; (3) resulted in no significant changes in joint population density, biomass, evenness of species. These results indicate that occurrence of the dominant species plays a major role in regulating the number of species and determining the organization of crop land rodent communities. Competition between the dominant species and other rodent populations for resources was limiting the number of species in the community.But we have not identified which components in resources were working in limiting the species number and species diversity by our relative simple experimental manipulations.

Key words: Community, Crop land, Experiment, Population, Rattus nitidus, Rodent

摘要： 1993～1995年我们在川西平原面积为2hm²的试验样地进行了试验, 内容是去除啮动物优势种大足鼠(Rattus nitidus) , 同时在相同生境中设置了1.5 hm²的对照样地。试验估计了优势物种在多大程度上影响其他啮齿动物种群。用捕鼠笼活捕进行监测后试验样地和对照样地间差异的成对数据t 检验显示, 移除大足鼠后: (1) 褐家鼠和黄胸鼠的种群密度、社鼠的生物量在某一年或整个研究期增加; (2)1995年及整个研究期的物种数和物种多样性Shannon 指数显著增加; (3) 结合密度、生物量和物种均匀性无明显改变。这些结果说明, 优势种的存在对农田啮齿群落物种数和组织有重要作用, 它与其它种群围绕资源的竞争限制了群落的物种数。但本研究相对简单的试验操作尚无法识别资源的什么成分在限制群落的物种数和物种多样性。

关键词: 大足鼠, 农田, 种群, 试验, 啮齿动物, 群落