民勤沙拐枣克隆种群构件结构及与环境因子的灰色关联分析

引入"构件"一词来表述植物体的不同组分,并在此基础上将其进一步发展为种群构件理论,极大地推动了植物种群生态学的发展(Bazzaz et al.,1978;Halle et al.,1978;Harper,1977;1980;钟章成,1992)。对木本植物而言,其地上部分枝或茎的顶端分生组织和侧生分生组织通过不断重复的、持续的活动产生新的分枝,构成了复杂的枝系构件和多样的外部形态特征。克隆种群对环境因子的反应首先表现在种群个体的构件结构上,对克隆植物构件的统计研究可涉及个体(基株)、分株和枝系3个水平(董鸣,1997),从构件间及其与环境因子的相

The Grey Relatedness Analysis between the Modular Structure of Clonal Population of Calligonum mongolicum and the Environmental Factors in the Minqin Desert

Study on modules of clonal populations has important theoretical and practical significance to understand the survival regularity and environmental adaptation mechanisms. The grey system theory was used to analyze correlations between environmental factors and the modular structure of clonal populations of Calligonum mongolicum in the Minqin desert at genet, ramet and branch system levels. The results showed that: 1) Heights of genet and ramet could reflect the development status and environment adaptability and indicate the growth state of the modules of the clonal population. 2) The ramet had more significant effects on the whole modular structure than the genet. 3) The first grade branch system was the foundation for the whole clonal plant. The internal correlation analysis showed that diameter growth and length growth coordinated with each other. The second grade branch system had limited impact and could be taken as a transition system. The third grade branch system significantly influenced the present year branch system whose growth was dependent on both the first grade and third grade branches. 4) The correlation among the modules showed a strong hierarchy, indicating that the whole pattern of the modular structure was relatively reasonable, and the population had strong adaptability to environment. 5) There were close correlations between the 16 environmental factors in study and the modules. Climate factors played a crucial role, soil bulk density and the content of soil organic matter also strongly affected the growth and development of C. mongolicum, and the soil moisture content was also a relatively sensitive factor.