濒危植物南川升麻种群数量动态的分析

Analysis on Numeric Dynamics of Population of Cimicifuga nanchuanensis,an Endangered Plant

运用种群静态生命表、生殖力表和 Leslie矩阵模型 ,研究了中国特有的濒危植物南川升麻种群数量动态过程。结果表明 ,南川升麻种群为衰退型种群 ,种群的净增殖率、内禀增长率和周限增长率较低 ,种群世代周期偏长 ,在 2 5 a内种群幼苗数量和总数量呈现出持续下降的趋势。南川升麻种群经历了两次死亡高峰期 ,受到了环境筛的强烈过滤作用。

Cimicifuga nanchuanensis is an endangered plant species, only distributed in Jinfu Mountain, Sichuan Province, China. At present, there exists a population. Based on overall investigation of age structure, seed production and seed natural germination rate etc, the numeric dynamics of Cimicifuga nanchuanensis population was studied by application of static life table, fecundity schedule and Leslie matrix. The results were as follows: Its net reproductive rate ( R 0 ), intrinsic rate of increase ( r m ) and finite rate of increase (λ) were 0.9610, -0.0014 and 0.9986, respectively. Values of these parameters (R 0<1, r m<0, λ<1) showed that the population was of decreasing type. By Leslie matrix model, it was predicted that in the coming 25years, the number of population would decrease by 50% or so, and the proportion of one-year-old seedlings would decrease, while the proportion of the old individuals would increase. The population underwent two high killing power periods. The first high killing power was caused by water stress, and the second one was mainly caused by shortage of light.