伊犁地区不同新疆野苹果种群的年龄结构分析

Age Structure Analysis of Different Malus sieversii Population in Yili Areas

新疆野苹果(Malus sieversii)作为中国Ⅱ级保护植物,近年来分布面积逐渐减小,为了揭示新疆野苹果种群的生存现状,本研究在新疆野苹果典型分布区新源县交吾托海、巩留县大莫合、霍城县大西沟共设置22块样地,通过样地调查获得数据,利用静态生命表、存活曲线、生存分析函数,结合种群结构动态指数,综合分析新疆野苹果的种群动态变化,以期为新疆野苹果资源的保护利用提供理论依据。结果表明:3个新疆野苹果种群年龄结构均呈现为不规则金字塔型,种群以中龄阶段的个体较多,缺少幼树和老树,种群存在衰退风险;3个新疆野苹果种群虽然存在幼苗分布,但个体数量较少,大莫合种群的新疆野苹果幼苗数量多于其他两个种群;随着新疆野苹果种群个体龄级的逐渐增大,种群期望寿命逐渐降低;存活曲线显示,3个新疆野苹果种群均趋向于Deevey-Ⅱ型,现阶段新疆野苹果种群相对稳定,但种群更新存在障碍,种群的长期稳定难以维持;新疆野苹果种群在到达第Ⅴ龄级后,进入生理衰老期,种群数量逐渐减少。幼龄个体的缺乏致使新疆野苹果种群趋于衰退,加强新疆野苹果幼龄个体与现存个体的保护是新疆野苹果种群可持续发展的关键。

As a second-class nationally protected plant,the distribution area of Malus sieversii has gradually decreased in recent years.In order to reveal the current survival situation of the Malus sieversii populations,this study set a total of 22 plots in Jiaowutuohai of Xinyuan County,Damohe of Gongliu County,and Daxigou of Huocheng County in the typical distribution area of Malus sieversii.Through the sample plot survey to obtain the data,using static life table,survival curve,survival analysis function,combined with population structure dynamic index,comprehensive analysis of Malus sieversii population dynamic changes,hoping to provide a theoretical basis for the protection and utilization of Malus sieversii resources.The results show that:the age structure of the three Malus sieversii populations is irregular pyramidal,the population is more middle-aged,and there is a lack of young and old trees,and the population is at risk of decline;although there are seedlings distributed in the three Malus sieversii populations,the number of individuals is small,and the number of seedlings in the Damohe population is larger than other two populations;with the individual age of the Malus sieversii population gradually increases,the life expectancy of the population gradually decreases;the survival curve shows that the three Malus sieversii populations tend to be Deevey-Ⅱ.At present,the Malus sieversii population is relatively stable,but the population regeneration exists obstacles,long term stability of the population is difficult to maintain;after theⅤage class,the Malus sieversii population entered a physiological aging period,and the population gradually decreased.The lack of young individuals has led to the decline of Malus sieversii population.Strengthening the protection of young and existing individuals in Malus sieversii is the key to the sustainable development of Malus sieversii populations.