黄荆山红椿种群动态分析

为探究珍稀植物红椿天然种群濒危机制,在黄荆山红椿采用相邻格子法设置2个20 m×20 m样方进行调查,划分了红椿龄级结构,分析了种群龄级数量动态指数,编制了种群的特定时间生命表,分析了存活曲线。结果表明:12个种群均为增长型种群;2T1种群第5龄级dx达到峰值,消失率Kx最大;T2种群dx峰值在第6龄级,消失率Kx最大;2个种群Ex最大值均在第1龄级,随龄级递增逐渐下降;3存活曲线为DeeveyⅡ型,表明各龄级具有相同的死亡率。红椿种群的龄级结构特征与其强阳性特征和竞争密切相关人为"正向干扰"可以促进红椿天然群落的更新与保护。

Analysis of Toona ciliata Population Dynimics in Huangjing Mountain

To explore the endangering mechanism of population of the rare plant,Toona ciliata,we classified T.ciliate populations into twelve age classes,and analyzed dynamic indexes of plant quantity,and set up the static life table of two populations,and drew and analyzed the survival curves of T.ciliata by field survey and statistical analyses of two typical sampling plots of T.ciliata in Huangjing Mountain.The result indicated:First,two populations belonged to growth type.Second,with the T1 population,the mortality rate peak (qx )and maximum Kx fell in 5 th age class;the mortality rate peak (qx)and maximum Kxof the T2 population were in the 6th age class;the life expectation rate (Ex)of two pop-ulations were the highest at the 1st age class,and then declined gradually with the age class increasing.Third,the mortali-ty rate curves of two populations conformed to Deevey Ⅱ,and this indicated the approximately equal mortality rates dur-ing the whole life circle.This research revealed that the growth and development of T.ciliata populations conformed to its strongly light-demanding characteristics and competitions.The key to the restoration and protection of natural T.cili-ate population,therefore,lies in the “positive artificial disturbance”.