Abstract: In this paper the time series analysis method re and the seasonality index were applied to characterize seasonal fluctuations，seasonality and periodicity of the6 ecolgical variables (number of species，number of individuals，biomass，index of shannon and Simpson of species diversity and evenness of the rodent community)in the Chihuahuan Desert，which was composed 17 species of 10 genera of 4 farallies．
The results suggested that(1)one or two of the 6 variables were maximum every season．Except number of individuals and evenness，the other 4 variabhs were minimum in winter ；(2)number of species and biomass，number of specise and two Indexes of species diversity，and two indexes of species diversity showed similarly aeasonaI fluctuations;(3)the negative correlations between seasonaI series of 5 variables，except number of indiviuals，and density series of 8 species populations weRE signiFicant ;(4)number of species showed remarkable seasonality with seasonality Index= 0.628；(5)no periodicity was found in number of species，number of individuals and biomass．The time patterns of dynamics of the rodent community were discussed，which were owed mainly to dlspersal and dormancy of the component species populations of the community．

Key words: Chihuahuan Desert, Community, Ecological time series, Rodents, SeasonaL fLuetuations

摘要： 本文利用时间序列分析方法和季节性指标，讨论了北美Chihuahuan荒漠由4科10属17种啮齿动物组成的群落的物种数，单位面积个体数与生物量，物种多样性的Shannon与Simpson指数和均匀性等6个变量的季节变动，季节性和周期性。结果表明 (1)每个季节都有变量达到最大值，但除个体数和均匀性外，其余4个变量均在冬季达到最小值；(2)物种数与生物量及两个物种多样性指数之间，以及两个物种多样性指数相互之间有类似的季节变动规律；(3)除个体数外，群落数量动态的其他变量与8个物种种群的密度存在着显著的负相关关系；(4)物种数有最明显的季节性，季节性指标SI=0.628；(5)物种数、个体数和生物量在92个月的研究期中未显示出任何周期性。最后总结了该啮齿动物群落动态的时间模式，提出组成物群的扩散和休眠行为是形成这些模式的主要原因．

关键词: Chlhuahuan荒漠, 生态时间序列, 季节变动, 啮齿动物, 群落