Branch Structure Characteristics of Betula Platyphylla in Different Habitats in Mountainous Forests of Northwest Hebei
The branch pattern was studied from the perspective of different habitats and trunk diameters,in order to reveal the difference of structural complexity and growth strategies of trees,and to provide theoretical basis for forest management in the mountainous region of northwest Hebei.Linear regression and non-parametric Kruskal-Wallis test were used to analyze the effects of DBH(diameter at breast height)and habitat on the branching pattern of birch(Betula platyphyllum Suk.)in pure and three typical mixed forests in northwestern Hebei Province.Results show these as follows.The DBH of the trunk,branch length,basal diameter and branch biomass of birch increase significantly with DBH(p＜0.05).In the same habitat,the branch length,basal diameter and biomass of birch decrease with the ascent of branch rank,while the branch length ratio,branch diameter ratio and branch rate increase with the ascent of branch rank.The branch length,branch diameter and branch biomass at all levels are similar:mixed forest Ⅰ(Birch-Larch)＞mixed forest Ⅲ(Birch-Apricot-Poplar-Sylvestre pine)＞Pure Birch forest＞mixed forest Ⅱ(Birch-Spruce).The results show that the DBH and habitat of birch can affect the branching pattern.The branch length,basal diameter,biomass and branching density of birch-larch mixed forest are better than those of other forest types,so as to maximize the environmental resources.The birch-larch mixed forest is the most suitable habitat for birch growth in northwestern Hebei.
万方数据
维普
