关键词: 木棉, 生境要素, 树形结构, 叶性状, 冗余分析, 结构方程模型

Abstract: Morphology and structure of plants are the results from the joint action of itself and the external environment. In order to analyze the correlation between tree shape structure and leaf trait of Bombax ceiba, and to explore the influence of topographic, soil, and meteorological elements on its growth shape, and to reveal its growth strategy and adaptation mechanism, we studied 230 B. ceiba trees in Xishuangbanna National Nature Reserve of Yunnan Province and measured six tree shape structure indexes, eight leaf trait indexes, and habitat elements of regional topographic, meteorology, and soil. The effects and explantation of habitat elements on tree shape structure and leaf trait of B. ceiba were analyzed by structural equation model and variation decomposition. The results were as follows:(1)There were correlations among the indexes of tree shape structure and among the indexes of leaf trait(P < 0.05).(2)The observed indexes of habitat elements had a strong influence on the growth indexes of B. ceiba leaves. The mean annual precipitation, slope and average temperature had a higher interpretation rate on the growth indexes of B. ceiba leaves, and were the dominant habitat indexes affecting the growth of B. ceiba.(3)According to the standardized path coefficient, the three habitat elements had the same effects on tree shape structure and leaf trait of B. ceiba, and all of them were in the order of topographic element>meteorological element>soil element.(4)The superposition of three habitat elements explained that tree shape structure and leaf trait were 43.5% and 12.3%, respectively, indicating that the response of tree shape structure to habitat environment was greater than that of leaf trait to environment. The results of this study preliminarily explore the adaptation strategies of different growth indexes to environmental elements of B. ceiba, which provides theoretical basis and practical reference for the cultivation and propagation of B. ceiba in heterogeneous habitats and efficient management of B. ceiba plantation.

Key words: Bombax ceiba, habitat elements, tree shape structure, leaf trait, redundancy analysis, structural equation model