次改林地鼢鼠种群年龄结构和繁殖特性动态研究

Dynamics of age structure and breeding characteristics of zokor population in the improved secondary forests

通过对次改林地鼢鼠种群结构和繁殖参数的11 a研究发现,鼢鼠种群是一个稳定而略有增长的种群。其成年Ⅱ组和老年组个体数量少,亚成年组和成年Ⅰ组的数量较多。亚成体和成年Ⅰ组的组成比与雌雄比呈显著的正相关,成年Ⅱ组的组成比与雌雄比呈极显著的负相关,老年组的组成比与雌雄性比呈显著的负相关。林地鼢鼠种群是通过雌雄鼠的数量关系来调节种群繁殖。在鼢鼠密度下降阶段,可以用前一年林地鼢鼠的成亚比预测下一年林地的鼢鼠种群数量。林地鼢鼠种群繁殖力在造林后第2—4年有一个增加的过程,第4年以后,繁殖力逐年降低。繁殖参数与成亚比呈负相关,与雌雄比呈极显著的正相关。

Eleven years＇ study on the age structure and breeding characteristics of zokor population in the improved secondary forests in loess plateau showed that zokor was a stable population with slight increase. Its adult Ⅱ group and old age group were small in number, sub-adult and adult Ⅰ group were large in number, The correlation between the female-male ratio and constitutional ratio of sub-adult and adult Ⅰ was remarkably positive while that of the adult Ⅱ group and the old adult group was significantly negative. The population breeding was regulated by the quantitative relationships between female and male in the woodland, When the zokor population was on the decline,its population density in the following year could be forecasted with the adult-sub-adult ratio of the year. In the improved secondary forests the breeding ability of zokor increased between the 2nd year and 4th year and then decreased gradually after the 4th year, There was a negative correlation between the breeding parameter and the adult-sub-adult ratio and a salient positive correlation between the breeding parameter and the femalemale ratio.