巴山水青冈天然种群结构及动态分析

Structure and Dynamic Characteristics of Wild Population of Fagus pashanica

为了分析巴山水青冈天然更新种群的数量特征及其动态,在实地调查的基础上,编制巴山水青冈种群静态生命表,分析其存活曲线、死亡率和消失率曲线,并运用时间序列模型预测种群数量动态。结果表明:巴山水青冈幼龄个体较丰富,中老龄个体较少。考虑外界环境干扰时,种群结构数量变化动态指数V’pi=0.03%,种群存活曲线趋于Deevey-Ⅱ型。种群死亡率和消失率都表现为生长前期小于生长后期,个体平均期望寿命在第1龄级最大。时间序列预测表明,该种群具备一定的恢复能力,但其老龄个体数呈急剧减少趋势,需要加强巴山水青冈林的管理,重点是对现有种群及其生境的保护和维持,减少人为活动的破坏,并采取适当的人工干预措施。

This study was conducted to determine the status,analyze the past population structure and forecast the future population dynamics of Fagus pashanica population. Through a field investigation,the population,the life table was established,the survival curve,killing power curve and mortality rate curve were analyzed,and the population dynamics were by a time-sequence model. The results showed that the number of young individuals was larger than that of middle-aged and old individuals. Considering the external enviroment disturbance,V＇pi= 0. 03%,the survival curve trended to Deevey-Ⅱtype. The killing power curve and the mortality rate curve of population were all showed that the population in early growth stage was smaller than that in later growth stage,the life expectancy of Fagus pashanica was highest in age-class one. The time-sequence model predicted that the number of different classes would increase after many years,but the elderly individual number showed a trend of sharp drop. As a result,the crucial factors for the natural regeneration and restoration of Fagus pashanica population in research area were the protection of living individuals and their habitat and the revegetation by human.