首页分享亚热带常绿阔叶林89种木本植物一级根直径的变异

亚热带常绿阔叶林89种木本植物一级根直径的变异

来源：花匠小妙招时间：2025-01-18 00:53

摘要：

细根直径变异是根系形态变化的常见形式, 对细根变异研究具有重要意义。为了揭示亚热带天然常绿阔叶林一级根直径变异特征, 该研究选取福建省建瓯市万木林自然保护区天然常绿阔叶林的89种木本植物进行研究。每个树种选取胸径或地径相近的3株, 用完整土块法进行根系取样, 用根序法对根系进行分级。采用单因素方差分析分别检验叶片习性(常绿、落叶树种)、生长型(乔木、小乔木或灌木、灌木)和主要科之间一级根直径的差异; 通过计算Blomberg’s K值以检验系统发育信号; 利用线性回归方法, 分析科水平的分化时间与一级根直径的相关性。结果显示: 1)亚热带常绿阔叶林一级根直径变异系数为23%; 2)常绿树种与落叶树种一级根直径没有显著差异, 但灌木一级根直径显著小于小乔木或灌木、乔木; 3)一级根直径系统发育信号不显著, 科水平分化时间与一级根直径呈正相关关系。研究结果表明, 亚热带天然常绿阔叶林木本植物一级根直径变异受系统发育影响较小, 但受生长型影响, 表现为一定的趋同适应。

关键词: 直径变异, 一级根, 亚热带常绿阔叶林, 系统发育

Abstract:

Aims The diameter variation of fine roots plays an important role for the study of fine root variation. Phylogeny is a significant factor. In order to examine the diameter variation of the first-order roots in subtropical evergreen broadleaved forests, we investigated 89 woody plant species from a natural evergreen broadleaved forest in Wanmulin Nature Reserve, Jianou, Fujian Province.Methods We selected three trees of each species with similar diameters at breast height or ground diameters, and sampled the root system with intact soil block method. We classed fine root with root order method. One-way ANOVA was used to test the first-order root diameter difference among the life forms (evergreen and deciduous trees), growth forms (tree, semi-tree or shrub and shrub) and the taxonomic classes. Then the Blomberg’s K value was calculated to determine phylogenetic signal. We analyzed the correlation between divergence time and first-order root diameter by using linear regression from family perspective.Important findings 1) The coefficient of variation for the first-order root diameter was 23% in this subtropical evergreen broad-leaved forest. 2) There were no differences in first-order root diameter between evergreen and deciduous trees, but that of the shrubs was significantly different from that of the semi-tree, shrub and tree species. 3) Phylogenetic signal in first-order root diameter was not significant. In addition, the divergence time was positively correlated with the first-order root diameter in the family-level. These results showed that, the variations for first-order root diameter in the tested subtropical woody species was little affected by phylogenetic structure.

Key words: diameter variation, first-order root, subtropical evergreen broadleaved forest, phylogeny