林地鼢鼠发生规律与林分郁闭度的模型分析

通过对次改林地11年的鼢鼠发生和林分郁闭度关系研究发现,鼢鼠密度上升期,鼢鼠密度、雌雄比与郁闭度呈递增关系,成亚比与郁闭度呈递减关系;密度下降期,随着林木的增长,林分郁闭度加大,鼢鼠密度降低,雌雄比下降,成亚比上升,并逐渐趋向稳定。全面清坡、竖向清坡和块状清坡造林,林地鼢鼠对林分郁闭度适应的最大值在0.430左右,范围在0.399～0.458之间;水平带状造林和更新林,林地鼢鼠对林分郁闭度适应的最大值在0.584左右,范围为0.568～0.585。鼢鼠各繁殖参数与郁闭度的关系总体符合一元三次回归模型。繁殖上升过程,繁殖参数与林分郁闭度呈递增关系,林地鼢鼠怀孕率和繁殖指数的最佳适应林分郁闭度为0.290,平均胎仔数的最佳林分郁闭度为0.210,取值范围均在0.060～0.430之间。林地鼢鼠繁殖强度下降过程,繁殖参数与林分郁闭度呈递减关系。

Model Analysis of the Outbreak Regularity of Zokor and the Shade Density

The relationship between the zokor occurrence and canopy density was studied in 5 different types of 11-year-old improved secondary forests ny regular sample plot survey.The results showed that in the rising period,zokor density and the ratio of female to male were positively correlated to the canopy density,the ratio of adult to sub-adult however,was negatively correlated to the canopy density.In the declining period,as the growth of forest,canopy density increased,the zokor density and ratio of female to male decreased,the ratio of adult to sub-adult increased,and tended stable gradully.The maximum adaptive value of canopy density for zokor was about 0.430,ranging between 0.399~0.458 in clear cutting forest,vertical cutting forest,and block cutting forest;it was about 0.584,ranging between 0.568~0.585 in horizontal cutting forest,and regenerated forest.The relationship between reproductive indices of zokor and canopy density was in accordance with cubic regression equations.In the rising period of zokor reproduction,reproductive indices of zokor was positively correlated to canopy density,the optimal adaptive value of canopy density for zokor pregnant rate and reproductive indices was about 0.290,and 0.210 for average fetus,ranging between 0.060~0.430.In the declining period of reproductive intensity of zokor,reproductive index was negatively correlated to canopy density.