不同放牧方式对大针茅草原啮齿动物群落多样性的影响

Effects of Different Grazing Patterns on Community Diversity of Rodent in Stipa grandis Steppe

2013-2015年,采用标志重捕法对内蒙古呼伦贝尔大针茅草原,季节轮牧区、按月轮牧区、连续放牧区和过牧区4种不同放牧方式及禁牧区(对照区)下啮齿动物进行了专门调查,对啮齿动物群落结构、啮齿动物群落相似性和多样性特征进行了研究.结果表明:1.不同放牧使啮齿动物群落结构发生了一定的变化.放牧增加了啮齿动物数量,使优势种出现了差异.连续放牧区和过牧区优势种为草原黄鼠;按月轮牧、季节轮牧和禁牧区优势种为黑线仓鼠.2.不同的放牧方式导致了啮齿动物群落相似性不同。按月轮牧与季节轮牧相似性指数最大,连续放牧与过牧相似性指数最大;禁牧与过牧相似性指数最大.3.连续放牧和过牧增加了啮齿动物群落多样性,按月轮牧和季节轮牧降低了群落多样性.本研究认为,季节轮牧能够控制啮齿动物个体数量的同时可以降低啮齿动物群落多样性.

A field experiment with four grazing patterns,including continuous grazing, monthly grazing, seasonal grazing and over grazing,and grazing prohibition （control area）, was conducted to study the effect of different grazing patterns on rodent community structure, community similarity and diversity in the Stipa grandis steppe in HulunBuir from 2013 to 2015,using live trap method. This study showed that： 1） The rodent community structure was influenced by grazing patterns. Grazing increased the number of rodents and changed the dominant species. In continuous grazing and over grazing sites,the dominant specie was Spermophilus dauricus,while in monthly grazing, seasonal grazing and grazing prohibition sites the dominant specie was Cricetulus barabensis. 2） Dif- ferent grazing patterns lead to different rodent community similarity. Community similarity between monthly grazing and seasonal grazing, over grazing and continuous grazing, overgrazing and forbid- den grazing sites were significant lager than other combinations. 3） Over grazing and continuous grazing increased the rodent community diversity, while monthly grazing and seasonal grazing re- duced community diversity. These results suggested that seasonal grazing can control the number of rodents and reduce the community diversity.