海南岛甘什岭青梅种群结构与动态

Population Structure and Dynamics of Vatica mangachapoi in Ganshiling,Hainan Island,China

【目的】探讨海南岛甘什岭青梅种群的结构与动态,阐明其生存现状和数量动态,揭示其更新规律,以期为其保护与恢复重建策略的制定提供依据。【方法】采用样地调查法调查海南岛甘什岭青梅种群,根据调查数据绘制青梅种群结构(径级、高度、冠幅)图。以青梅径级结构代替年龄结构,采用匀滑技术编制青梅种群静态生命表,根据静态生命表数据,绘制青梅种群存活曲线、死亡率曲线和消失率曲线。应用生存分析中的生存函数、积累死亡率函数、死亡密度函数和危险率函数分析青梅种群生存现状。采用时间序列分析方法对青梅种群的龄级结构进行预测。【结果】青梅种群各龄级、高度级、冠幅级结构完整,种群具有良好的更新潜力,发展稳定,为增长型种群;种群静态生命表表明,青梅种群幼龄个体死亡率较低,中老龄个体死亡率较高,在Ⅳ径级中龄树阶段时死亡率和消失率最高;青梅种群的存活曲线为Deevey-Ⅱ型中的B1亚型;青梅种群死亡率和消失率曲线均呈现出先增后减变化趋势;生存分析表明,青梅种群具有快速衰减、中期竞争压力大的特点;时间序列预测结果表明,青梅种群更新能力强,能够快速恢复为稳定的种群结构,呈现出快速增长而后稳定发展的趋势。【结论】青梅种群幼苗数量多,能应对环境筛选以及竞争压力,能保证一定数量的个体进入下一龄级;但在青梅种群个体处于中龄阶段时,虽然在群落中占据了一定的空间和环境资源,因其进一步生长发育所面临的环境阻力及竞争压力大幅增加,只有少数个体能进入老龄阶段。

【Objective】To provide a theoretical basis for the protection,sustainable utilization and the formulation of restoration strategies of Vatica mangachapoi population,the structure and dynamics of V.mangachapoi population in Ganshiling,Hainan Island were studied,in order to elucidate the survival status and quantitative dynamics,and to reveal the patterns of regeneration.【Method】A field survey was carried out on V.mangachapoi population in sample plots in Ganshiling,Hainan Island.According to the characteristics of life history of the species and considering the results from previous researches,diameter,height and crown width were divided into classes and population structure was constructed using the classes.The static life table,survival curve,mortality curve,loss rate curve were produced using space to replace time which meant diameter structure instead of age structure.Four functions(survival,accumulated mortality,mortality density,and hazard rate)of survival analysis were used to analyze population dynamics of V.mangachapoi.Time series analysis method was used to predict the age structure of V.mangachapoi population.【Result】The population of V.mangachapoi had complete structures of age,height,and crown width,showing the stable development and good regeneration potential.The static life table showed that there were large differences of number of survival trees among different classes.The rate of mortality and loss were both the highest in age classⅣ.The population of V.mangachapoi fitted type B1 of Deevey-Ⅱ.The changes of mortality and loss rate were in similar trends.Four survival curves showed that the population of V.mangachapoi was decline in every stage,suffering from competitive pressures in the middle period.The prediction by the time series analysis showed that the population of V.mangachapoi had a high ability to regenerate and quickly restore to the stable population structure.【Conclusion】A large number of seedlings growing in the population of V.mangachapoi made them survive environmental elimination and competition pressure,enabling some individuals survive and grow into the next age class.However,in the middle and young age class,individuals occupy a certain space and environmental resources in the community,and the environmental stress and competition pressure increased substantially,only a few of individuals may grow into the later stage.