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祁连圆柏林是祁连山区阳坡分布的唯一常绿针叶乔木林。利用卫片和林相图机械布设50m×50m的样地50块,进行实地调查,用种群结构、生命表和生存函数分析方法,研究了冷龙岭西段山丹军马场林区祁连圆柏种群的生活史。结果表明:祁连圆柏种群结构具有明显的缺陷,小径阶个体数量偏少,属于衰退型种群,需要通过各种措施加强保护,促进林下天然更新和幼苗幼树的正常生长;种群存活曲线符合1n Lx=-0.0056x2-0.0525x+6.8293(R2=0.9549)方程,属于DeeveyⅡ型存活曲线,有相对稳定的死亡率;随着种群年龄的增加,种群对环境的适应能力增强,种群趋于稳定,种群的死亡率Px、消失率Kx保持相对稳定,死亡数Dx、存活数Lx、存活个体总数Tx都保持了稳定降低的趋势,生命期望Ex降低。种群的存活率和死亡密度函数随大小级增加呈单调下降趋势,累计死亡率和危险率函数呈单调上升趋势。
The Qilian round Berlin is the only evergreen coniferous arbor forest distributed in the sunny slope of Qilian Mountains. A total of 50 plots of 50m × 50m were planted by using satellite photos and forest photos. Field surveys were conducted. Population structure, life table and survival function analysis were used to study the population of Sabina przewalskii Life history. The results showed that the population structure of Sabina przewalskii had obvious defects. The population of small-diameter step was less than normal, which belonged to the declining population. It was necessary to strengthen the protection through various measures to promote the natural regeneration under the tree and the normal growth of seedling saplings. The population survival curve accorded with 1n Lx = -0.0056x2-0.0525x + 6.8293 (R2 = 0.9549), which belongs to the Deevey type Ⅱ survival curve and has a relatively stable mortality rate. With the increase of population age, the population adaptability to the environment is enhanced and the population tends to be stable. Population mortality Px, disappearance rate Kx remained relatively stable, the number of death Dx, the number of survivors Lx, the total number of surviving individuals Tx have maintained a steady decline in the life expectancy Ex decreased. The survival rate and the density function of population showed a monotonous decreasing trend with the increase of the size, and the cumulative mortality and risk function showed a monotonous upward trend.