鄂尔多斯沙地草场小毛足鼠种群数量动态分析

Analysis on the Population Dynamics of Desert Hamster in Ordos Sandland

目的 了解小毛足鼠种群数量变动因素。方法 1991～ 1998年 4～ 10月在中国农业科学院草原研究所鄂尔多斯沙地草场改良试验站 ,利用直线夹日法调查。结果 小毛足鼠为该地区优势种 ,该鼠数量变化季节性明显 ,年间变化差异较大。经过 8年调查 ,小毛足鼠数量变化经历了低谷 ( 1991～ 1992年 )、高峰 ( 1993年 )、下降 ( 1994年 )和低谷( 1995～ 1998年 ) 4个时期。结论 影响种群数量变动的主要因素有种群年龄组成中幼年组的百分比、怀孕率、繁殖指数以及该地区子午沙鼠、三趾跳鼠和黑线仓鼠的数量。

Objective To study on the elements of population dynamics of desert hamster ( Phodopus roborovskii ).Methods The population dynamics of desert hamster was investigated on Ordos sandland by rectilinear-trapping method in the middle ten days of each month from April to October during 1991-1998. Results The desert hamster was the dominant species of rodents on Ordes sandland.The seasonal and annual fluctuation of its population number were different year to year.The populaion dynamics fluctuated with valley(1991-1992),peak(1993), decrease(1994)and valley(1995-1998) among the 8 years. Conclusion The important elements of population dynamics were the population age structure, the pregnant rate, the reproductive indices and the population number of other species (little Chinese jird, northern three-toed jerboa and striped hamster).