黄山常绿阔叶林甜槠群落优势种种间关联分析

【目的】探讨黄山常绿阔叶林的物种组成、群落结构以及种间关联性。【方法】以黄山常绿阔叶林10.24 hm²动态监测样地为对象,在样地调查基础上,通过重要值排序确定了14个优势种,基于2×2列联表,采用方差比率法、χ²检验、联结系数(AC)和Pearson相关系数分析优势种在3个不同径级下的种间关联和相关关系。【结果】方差比率法检验显示,优势种在整体、中径级尺度呈相对独立关系,小径级尺度呈显著正关联,大径级尺度呈显著负关联; χ²检验显示,种对间呈显著关联与极显著关联,对数之和在整体、小、中、大径级下依次为29、29、30、25; AC联结系数检验显示,正负关联比在整体、小、中、大径级下依次为0.915、1.263、1.023、0.717; Pearson相关系数检验显示,正负相关比在整体、小、中、大径级下依次为0.896、1.275、0.936、0.542。【结论】黄山常绿阔叶林不同径级下的种对间关联关系存在明显差异; 种间正负关联比随着径级变大而减小,样地内种间竞争随着径级变大而增多及增强。

Interspecific association analysis of Castanopsis eyrei community in evergreen broad-leaved forests in Huangshan,Anhui Province

【Objective】We aimed to clarify species composition, community structure and interspecific associations of broad-leaved evergreen forests at Huangshan.【Method】We calculated the importance value of species using the survey data of the forest dynamics plot with an area of 10.24 hectares, and screened out 14 dominant species by their important value. By means of variance analysis, χ² test, AC index, and Pearson correlation coefficient based on the 2×2 contingency table, we investigated the interspecific association of 14 dominant species at three different diameter classes.【Result】The variance analysis showed that weak interspecific associations occur at both the whole community level and the medium diameter class, whereas a significantly positive association was found under the small diameter class, and a significantly negative association was found under the large diameter class. The χ² test showed that total number of species pairs with significant and extremely significant associations under the whole, small, medium and large diameter classes were 29, 29, 30 and 25, respectively. The AC index test shows that the positive-negative association ratio under whole, small, medium and large diameter classes were 0.915, 1.263, 1.023 and 0.717, respectively. Pearson correlation coefficient test showed that the positive-negative correlation ratio under whole, small, medium and large diameter classes were 0.896, 1.275, 0.936 and 0.542, respectively.【Conclusion】There is a significant difference in interspecific associations among species of different diameter classes. Ratio of the positive to negative associations of species pairs was found to be decreased with higher diameter classes, while interspecific competition in the plot intensifies with higher diameter classes.