藏东南高山松种群结构及动态特征

Population Structure and Dynamic Characteristics of Pinus densata in Southeast Tibet

种群结构及数量动态是种群生态学研究的核心问题.种群结构包括水平结构和垂直结构,水平结构主要是指种群径级结构、年龄结构及冠幅结构,垂直结构主要是指种群的高度结构.种群结构不仅反映了种群不同个体的配置情况,也反映了种群数量动态及其发展趋势,并在很大程度上反映了种群和环境间的相互关系及它们在群落中的作用和地位（范繁荣等,2008）.静态生命表和存活曲线是进行种群统计和研究种群数量动态变化的重要工具,生存分析的4个函数（生存函数S（i）、积累死亡率函数F（i）、死亡密度函数f（ti）和危险率函数λ（ti））可以辅助种群生命表分析,

After a comprehensive investigation on Pinus densata populations that distribute in southeast Tibet by transects and quadrats,this paper analyzed the diameter class,height class and crown width class,compiled the static life table,drew survival curve,mortality curve,killing power curve,and four survival function curve （Survival rate,accumulated mortality rate,morality density rate and hazard rate）,investigated population quantitative characteristics,and predicted population quantitative dynamics by a time sequence prediction model.The results showed that the individual number of P.densata was slight fluctuant with structure level （the diameter class,height class and crown width class）,but the number in the three structures was generally presented as the anti-“J” type,and the population belonged to growing type.The survival number of every diameter class had obvious difference,the mortality rate of age Ⅳ was relatively low （13％）,that of age Ⅷ was highest （70％）,and the average mortality rate accounted for 42％.The survival curve of P.densata population approached to the B1 subtype of Deevey-Ⅱ.With the increase of the population age class,the mortality rate had a similar change trend to the killing power,and they all presented double-peak curves.Four survival function curve for P.densata population indicated that the population would have an early reduction,a midterm stability,and a late recession because of physiological exhaustion.The time sequence model predicted that P.densata population had strong recovery capability,and the amount of population would have a different rising tendency in the upcoming 3,6 and 9 age classes.