濒危植物急尖长苞冷杉种群生命表分析

Analysis to the Life Table of Endangered Population Abies Georgei

急尖长苞冷杉是我国二级保护植物,处于易危状态。在西藏色季拉山,对急尖长苞冷杉种群全面调查的基础上,以种群生命表及生存理论为基础,编制色季拉山阳坡、阴坡及总体急尖长苞冷杉种群特定时间生命表,分别绘制存活曲线、死亡率曲线、亏损率曲线,以及积累死亡率函数、死亡密度函数和危险率函数曲线,并分析种群动态变化。结果表明:生长在阳坡、阴坡及总体的急尖长苞冷杉种群各龄级个体数量均随年龄增长呈直线下降趋势,生境对种群的结构和动态有较大影响,幼苗死亡率阴坡大于阳坡,老龄个体死亡率阳坡大于阴坡;生长在阳坡种群的存活曲线属Deevey-Ⅱ型中的B3亚型,生长在阴坡种群的存活曲线属Deevey-Ⅲ型,总体种群的存活曲线也属Deevey-Ⅲ型;三个生命表中引入的几个函数都能较好地说明了种群的结构和动态变化。研究结果可为该资源的管理及持续利用提供理论依据。

Abies georgei var.smithii is second-class protected species and in approximately endangered states in our country.After a comprehensive investigation on A.georgei population that distributes in Sejila mountain of Tibet,the life table was worked out,life characteristics and population dynamics were analyzed.The results showed that the individual number of A.georgei were decreased straightly with age class increasing,the habitat affected on the population structure and dynamics of A.georgei,seedling mortality rate of A.georgei that distributes in shady slope was more than that of sunny slope,adult mortality rate was opposite,the survival curve of the sunny slope population trend to the B3 subtype of Deevey-Ⅱ,the survival curve of the shady slope and total population trend to the type of Deevey-Ⅲ.The functions used in three life tables could well explain the structure and dynamics of A.georgei population.The research results provided the theoretical basis for management and sustainable utilization of A.georgei.