子午沙鼠种群数量动态及预测

Population dynamics and prediction on Meriones meridianus

子午沙鼠 ( Merionesmeridianus)是荒漠和半荒漠地区常见的鼠种之一。作者于 1 991～ 1 996年 4～ 1 0月每月中旬 ,在内蒙古达拉特旗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。利用直线夹日法在站内的流动沙丘、半流动沙丘、固定沙地、丘间滩地、林地和农田中开展了种群数量调查。 6a共布放 1 2 4 2 4 5个夹日 ,捕获鼠 74 98只 ,其中子午沙鼠1 4 0 8只 ,在各种鼠中占 1 8.78% ,居第三位。子午沙鼠种群数量季节消长特点 ,4～ 1 0月数量波动曲线有两个波峰 ,1 0月数量最低。种群数量季节消长有年间差异 ,6a中年度数量变动经历了“低谷→上升→高峰→下降→低谷”5个期。 1 991年为低谷期 ,1 992年为上升期 ,1 993～1 994年为高峰期 ,1 995年为下降期 ,1 996年又为低谷期 ,显示了一个变化周期。以捕获率为指标 ,分别作出短、中期预测模型 ;用繁殖指数为指标 ,作出长期预测模型。并开展了预测 。

Population dynamics of Meriones meridianus was investigated on Ordos sandland by rectilinear trapping method in the middle ten days of every month from April to October during 1991～1996.A total efforts of 124245 trapping days was made and 7498 rodents were captured among which 1408 specimens were Meriones meridianus. Seasonal fluctuation of the population numbers was significant and significant difference existed among years.In general,there were two peaks in population numbers in a year that occurred in May and July respectively and the former was higher than the latter.The lowest population number occurred in October.The population dynamics among years has undergone 4 phases complete cyclical fluctuations.The 4 phases were lowest point,inerease,peak and decrease which occurred in 1991,1992,1993～1994 and 1995,respectively.Another period started again from 1996,that was in the lowest point.Prediction models of short term and middle term were established with the index of capture rate,and of longterm models with reproduction index.