Multivariate Analysis of the Ecological Factors and the Modular Structure of Gordonia acumenata Young Tree Population in Mountain Jinyun, Sichuan, China
Abstract:On the basis of the theory of modularity and with the analysis of relatedness degree adopted in the grey system theory, the correlation of the ecological factors and the modular structure of young tree population of Gordonia acumenata in the slash, which was created by a windstorm on Mt. Jinyun in 1989, was investigated. The results show that the modular structure of four years old Gordonia acumenata population consisted mainly of five components, i.e. first grade branch system, second grade branch system, present year branch system, spatial structure system and leaf system. They could be expressed by the dynamic features such as the number or total diameter or total length of the first grade branches, the number or total diameter or total length of the second grade branches, the number of present year branches, the first grade branches of three years old, and the total number of leaves, respectively. The correlation among the former four components were very outstanding. The last one, including the area of the leaves situated on stem, the height of the first grade branch and the height of the first leaf on stem, were relatively stable and were slightly affected by other factors. Generally, the total N, total P, total K, organic matter content and pH-value of soil were more important, as compared with elevation, size of gap and slope gradient of the sample plot. Analysis of grey relatedness degree is simple and direct technique to research the correlation among the modular structure of plant population and ecological factors. To some extent, multiple linear regression can express the quantitative relation and mechanism of the action of them.