摘要
通过对九宫山惟一红椿(Toona ciliata Roem.)种群进行调查和数据统计分析,绘制了红椿自然种群的龄级结构图,量化分析了种群各龄级间个体数量、变化动态,编制了种群的特定时间生命表,分析了存活曲线、种群生存函数;运用时间序列模型预测红椿种群数量动态。结果表明,(1)Ⅰ龄级存活植株占总存活植株的45.64%,Ⅱ~Ⅳ龄级占28.20%,Ⅴ~Ⅵ龄级占13.33%,Ⅶ~Ⅻ龄级占12.82%;个体数量变化动态指数VⅠ最高,为62.92%,除V_(Ⅳ)和V_Ⅴ2个龄级间波动外,V_(pi)=45.96%,V_(pi′)=3.83%>0。(2)种群存活曲线:N_x=8.448 e^(-0.09x),R^2=0.956,符合DeeveyⅡ型存活曲线,说明种群在生活史各个阶段具有较为稳定的死亡率。(3)生存率函数S(i)单调下降,积累死亡率F_((i))呈单调上升,两者下降和上升的幅度前5个龄级高于后期,F_((i))到Ⅵ龄级达0.881。死亡密度函数f_((ti))随龄级逐渐下降,到Ⅷ龄级后稳定在0.003。危险率函数λ_((ti))出现Ⅴ、Ⅶ、Ⅺ龄级的3个峰值,均为0.250,龄级结构和动态分析的趋势一致。(4)对Ⅱ、Ⅳ、Ⅵ、Ⅷ龄级动态预测表明,种群各龄级个体数量呈增加-下降-平稳变化,种群趋于老龄化。总之,九宫山红椿种群受特定环境影响,改善了红椿林下幼苗在生长过程中的光照条件,光照环境筛和竞争成为中间龄级植株的抑制条件,因此该种群为增长型种群,但趋于老龄化。在管理上应针对不同阶段种群生长发育特征,采取适当措施,使种群健康发展。
By field survey and statistic data analyses of Toona ciliata Roem. population in Jiugong Mountain Nature Reserve in Hubei province, the age-class structure figure was drawn; and the quantitative analyses of plant individuals and change dynamics in different age class were conducted; the life table in specific time spectrum of the population was made, and the survival curve, survivorship function and life-expectation figures were analyzed. The result indicated that firstly, the survival number of age-class Ⅰ accounted for 45.64% of the total number, while age class Ⅱ to Ⅳ accounted for 28.20%; V toⅥ accounted for 13.33%, Ⅶ to Ⅶ accounted for 12.82%. The dynamic change index of the age structure of the population V pi=45.96%〉0 and V pi＇=3.83%〉0,with V 1 surging to the highest 62.92%,indicating the population was in growth form. Second, the survival curve of the population was in accordance with the curve of Deevey Ⅱ,with Nx=8.448 e-0.09x,R2=0.956, revealing a comparatively stable mortality rate in the life history of the T. ciliata population. Third, livability function S（i） were in mono-tonic decrease while accumulative mortality rate in monotonic increase, and the changing extent of the former 5 age-classes was sharper than that of the latter, with F（i） reaching 0.881 only on age-class Ⅵ;the mortality density function f（ti） descended gradually with the age-class and stabilized at 0.003 on the Ⅷ age class;the hazard rate function λ（ti） had 3 same peak val-ues, 0.250 on the V,Ⅶ and Ⅺ age-classes, showing the same tendency with the previous quantitative analyses. Fourth, the time-dynamic expectation of the population to Ⅱ,Ⅳ,Ⅵ and Ⅷ age classes showed a approximate trend of increaseing, de-creaseing and then stabilizing, developing an aging tendency. The research demonstrate that the T. ciliata population of Jiu-gong Mountain was regulated with a specific environment, which assisted to enhance the light condition of the saplings, and environmental sieves of light a
出处
《湖北农业科学》
2017年第10期1873-1877,1887,共6页
Hubei Agricultural Sciences
基金
湖北省公益性研究项目(40-2012DBA40001)
