不同干扰和尺度下荒漠啮齿动物群落格局

2002~2004年,在内蒙古阿拉善荒漠区选择4种不同干扰生境,在3个空间尺度上对啮齿动物群落格局进行了研究。结果表明,在不同干扰和尺度下,荒漠啮齿动物群落格局具有明显差异。随着尺度的增大,不同干扰生境种类组成明显增加,优势种组成格局明显变化,开垦干扰下子午沙鼠在3个空间尺度上都为优势种;轮牧干扰下子午沙鼠只是在小尺度上占有优势,而小毛足鼠在2个较大空间尺度上始终为优势种;过牧干扰下同样子午沙鼠只是在小尺度上占有优势,而三趾跳鼠在2个较大空间尺度上始终为优势种;禁牧干扰下子午沙鼠和黑线仓鼠的优势地位在1hm2和10hm22个空间尺度上交替出现,但在40hm2空间尺度则同时成为优势种。在荒漠栖息地破碎化过程中,啮齿动物群落格局在不同空间尺度上受到了明显的影响。三趾跳鼠在群落中数量升高是荒漠生境开始破碎化的表现之一。

THE PATTERN OF DESERT RODENT COMMUNITY UNDER DIFFERENT DISTURBANCE AND SCALES

The habitats under four kinds of different disturbance were selected in Alashan Desert of Inner Mongolia in which the patterns of rodent communities were studied on three spatial scales.The results showed that the patterns of desert rodent communities appeared evident difference under different disturbance and scales.With scaling up,the rodent species under different disturbance increased,and the composition patterns of dominant species in communities changed as follows: Meriones meridianus was the dominant species on three spatial scales under farmland;Meriones meridianus was the dominant species only on small spatial scales,but Phodopus roborovskii was the dominant species on other two larger spatial scales under rotational grazing;Meriones meridianus was the dominant species only on small spatial scales,but Dipus sagitta was the dominant species on other two larger spatial scales under over grazing;Meriones meridianus and Cricetulus barabensis as a dominant species appeared alternately between 1hm2 and 10hm2 scales,but on the 40hm2 scale,they both were dominant species under forbidden grazing disturbance.The patterns of rodent communities were evidently influenced by fragmented desert habitats.It was the one of the phenomenon of desert habitats starting to fragment that the numbers of Dipus sagitta species in rodent community increased.