濒危兰科植物流苏石斛的种群数量动态

运用静态生命表、生殖力表和Leslie矩阵模型,研究了云南西双版纳地区流苏石斛两个种群——A种群(21°58′N,101°13′E,保护区之外)和B种群(21°54′N,101°17′E,保护区内)的种群数量动态.结果表明:种群存活曲线表现为Deevey-型.A、B种群均表现出幼龄个体死亡率高,中龄级个体数量少,说明中龄阶段曾受到较大的人为干扰.种群的净增长率(Ro)、内禀增长率(rm)和周限增长率(λ)都较低,表现为衰退种群,Leslie矩阵模型分析表明在未来25年种群各龄级的个体数及种群总数均表现出持续下降趋势.种群下降可能是由于当地人为的采挖和严重的生境破碎化所导致.图2表4参16

Numeric Dynamics of Population of Endangered Species Dendrobium fimbriatum, Orchidaceae

This research studied the numeric dynamics of two populations of Dendrobium fimbriatum(21°58′N,101°13′E,human disturbance and 21°54′N,101°17′E,in-situ conservation),an endangered species of Orchidaceae in Xishuangbanna Dai Autonomous Prefecture,Yunnan,China.The static life table,the fecundity schedule and the Leslie matrix model were applied to understand the numeric dynamics and the age structure of the population.The results showed that the survival curves of two populations were the Deevey-type.The net reproduction rate(Ro),the intrinsic increase rate(rm) and the finite increase rate(λ) of the two populations were all very low,indicating that the two populations were in a situation of downward tendency.The Leslie matrix model predicted that in the next 25 years the number of the two populations would continuously decrease.The key threats to this species are most likely human’s disturbance and deforestation and habitat fragmentation.Fig 2,Tab 4,Ref 16