新疆野扁桃种群年龄结构及动态分析

Age structure and dynamic analysis of Amygdalus ledebouriana population in Xinjiang,China

以新疆巴尔鲁克山的野扁桃(Amygdalus ledebouriana)种群为研究对象,通过对其进行年龄结构与动态分析,可以为野扁桃种群的保护管理及恢复提供一定的理论依据及研究基础。该研究采用典型样方法对野扁桃的种群数量进行了调查与统计,应用“空间代替时间”及匀滑修正技术,编制野扁桃种群静态生命表,分析野扁桃种群数量动态变化。主要结果有:1)野扁桃种群第Ⅲ龄级个体数量最多,占总体数量的19.19%,种群的个体数量随着龄级的增加先增加后减少,种群径级结构呈“纺锤”形,野扁桃种群年龄结构属于衰退型;2)野扁桃存活曲线趋近Deevey-Ⅱ型分布,且种群的死亡高峰出现在第Ⅷ龄级,死亡率为58%;3)野扁桃种群动态变化指数(Vpi)、受外界干扰时野扁桃种群动态变化指数(V′pi)均大于0,但V′pi趋近于0,种群在外部环境干扰下承担的风险概率最大值(Pmax)为0.38%,说明该种群受外界随机干扰时增长趋势不明显;4)在未来2、3、4、5、6、7、8、9、10个龄级时间后,幼、中龄个体数量逐渐减少,老龄个体占主导地位。幼龄个体中实生苗的缺乏是野扁桃种群衰退的主要原因,因此建议在未来的研究中增加野扁桃实生苗更新方面的研究工作,并对野巴旦杏自然保护区封山育林,适当进行人工抚育,以保证其种群的正常更新。

Aims Taking the population of Amygdalus ledebouriana in Balruk Mountain of Xinjiang as the research object,through the investigation of the natural population of A.ledebouriana in Xinjiang,and to provide a certain theory and research basis for the conservation,management and restoration of A.ledebouriana population.Methods The population of A.ledebouriana was investigated and counted by typical sample method.The static life table of A.ledebouriana population was compiled using“space substitution time”and uniform sliding technologies,and thus the dynamic change of the population number was analyzed.Important findings 1)The number of individuals in the Ⅲ age class of A.ledebouriana population in Xinjiang was the largest,accounting for 19.19% of the total individual number.The number of individual plants in the population increased first and then decreased with the increase of age class.The diameter class structure of the population was“spindle”.The age structure of A.ledebouriana population in Xinjiang belongs to the recession type.2)The survival curve of A.ledebouriana was close to the distribution of Deevey-Ⅱ,and the death peak of the population appeared in the Ⅷ age class,with a mortality rate of 58%.3)Dynamic change index(Vpi),dynamic change index under external disturbance(V′pi)of A.ledebouriana population>0,but V'pi was close to 0,and the maximum risk probability in random disturbance(Pmax)of the population under external environmental interference was 0.38%,indicating that the growth trend of the population was not obvious when it was randomly disturbed by the outside world.4)After 2,3,4,5,6,7,8,9 and 10 age classes in the future,the number of young and middle-aged individuals gradually decreases,and the elderly individuals dominate.The lack of seedlings in young individuals is one of the main reasons for the decline of A.ledebouriana population in Xinjiang.Therefore,in order to ensure the normal regeneration of A.ledebouriana population,it is very important to adopt some valid measures,for example,increase the research in the regeneration of A.ledebouriana seedlings in the future,including properly carrying out artificial tending,and protect the A.ledebouriana population by closing the mountains and raising forests in Xinjiang.