祁门浙江楠种群结构与数量动态研究

Population Structure and Quantitative Dynamics of Pheobe chekiangensis in Qimen County

【目的】更好地了解濒危植物浙江楠(Pheobe chekiangensis C.B.Shang)种群的结构与现状,为该树种的保护和生态恢复提供依据。【方法】在样方数据调查的基础上,运用种群生命表、时间序列预测模型等方法,对安徽祁门地区浙江楠的种群结构和种群数量动态变化进行研究。【结果】祁门浙江楠种群在结构上大体呈"金字塔"形,幼树数量较大,中间径级和大径级个体数量保持一定水平。生命表数据显示死亡率(qx)第I、第V和第VI径级均为负值,说明幼树前期死亡率较高,其自身生物学特性与环境因素是形成这一现象的主要原因。期望值(ex)最大值出现在第III径级,Deevey III型曲线斜率大,死亡率和致死率(Kx)曲线有一定波动,表明祁门浙江楠种群结构具有一定复杂性和不稳定性。种群结构动态指数在无干扰和非完全随机干扰情况下分别为0.249和0.134,偏离0的程度低,种群较为稳定,这与时间序列预测结论基本一致。【结论】目前,祁门浙江楠种群结构相对稳定,采取种群就地保护、封山育林保护生境、加强种群幼苗抚育管理,建立基因通道和确保遗传多样性条件下加强回归引种等将更有利于种群的生长发育,促进种群恢复发展。

【Objective】The aim of the study was to understand the structure and status of endangered plant Pheobe chekiangensis and to provide a basis for the protection and ecological restoration of this plant.【Method】Based on plot investigation,static life table,quantitative dynamics of population and forecasting model of time sequence analysis were used to study the P.chekiangensis in Qimen county,Anhui province.【Results】The P.chekiangensis in Qimen county presented apyramid-shape structure,indicating that there were a large number of seedlings and saplings and certain number of mid-size class and large-size classs trees.Life table showed that mortality rate（qx）of I,V and VI size class was minus value,implying that lots of seedlings died in the earlier life stage.This may be accountable to its own biological characteristics and environmental factors.Expectations（ex）maximum was in the III size class.The survival curve was Deevey-III.There were dramatic changes in death curve and killing curve（Kx）,indicating that the complexity and instability were in the process of natural regeneration.The population dynamic index was 0.249 and 0.134,respectively,under non-interference and incompletely random interference and it deviated from 0slightly,suggesting that the population was stable and it was consistent with the results of time sequence analysis.【Conclusion】At present,the population structure of P.chekian-gensis in Qimen county was relatively stable.The population recovery and development will benefit from population protection in local areas,closing hillsides to facilitate afforestation,eco-environment protection,enhancing nurturing management of seedlings,establishing gene channels,ensuring regression and introduction on condition of the gene diversity.