南京紫金山糙叶树种群结构与动态

为明晰地带性植被糙叶树种群结构与动态特征，根据1 hm²固定样地中优势种糙叶树的每木调查结果，通过种群静态生命表、存活曲线、生存分析函数及时间序列模型，对糙叶树种群的结构动态进行分析。结果表明：1)糙叶树种群属于增长型，在自然干扰下，种群数量变化动态指数为3.04%,表明该种群能够在当前演替阶段保持稳定。2)种群存活曲线趋于Deevey-Ⅱ直线型B₃亚型，死亡率和消失率均表现出波动性特征。3)时间序列预测表明，在经过2～5个龄级后，除Ⅸ和Ⅺ龄级外，种群各龄级的个体数量均有不同程度增长。综上所述，虽然紫金山糙叶树种群个体数量在当前演替阶段能够维持稳定，但种群在幼中龄过渡阶段死亡率(43.2%)和死亡密度(9.7%)偏高，需通过适度开展科学的经营性择伐等森林抚育措施，及时伐除病残木，营造小林窗，改善林内生存环境，从而促进糙叶树种群的天然更新与苗木生长。

Population Structure and Dynamics of Aphananthe aspera on the Zijin Mountain in Nanjing

In order to understand the population structure and dynamics of Aphananthe aspera occurring in the Zijin Mountain,Nanjing,on the basis of the data collected from a 1 hm² plot,the A.aspera population dynamics were analyzed using a static life table,depicted survival and function curves,and time-sequence model.The results showed that 1) the A.aspera population was of an expanding type.The dynamic index in age structure of A.aspera population under the natural disturbance was 3.04%,indicating that the population was stable at the succession stage.2) The survival curve of A.aspera population tended to be the linear subtype B₃ of Deevey-Ⅱ.The curves of mortality and disappearance rates showed a fluctuating pattern.3) The time series prediction model showed that the individual number of the population in each age class would increase by various extents after underwent 2,3,4 and 5 age classes except for age class Ⅸ and Ⅺ.In conclusion,although the A.aspera population was stable at the succession stage,the mortality rate (43.2%) and mortality density (9.7%) were higher in the growing to middle-aged stages.It was suggested that the scientific selective cutting for forest tending should be adopted to cut off the diseased and dead woods,to form forest gaps,and to improve the shine and space in the understory for mitigating the pressure of intraspecific and interspecific competition and to promote the growing and regeneration of the seedling in the A.aspera population.