摘要
一个较大的植物区系的内部是不均一的，异质的原因是多方面的，如水平距离的差异、海拔高度的差异、生境异质性等。本文讨论了传统的区系间相似性比较系数的不足，采用多元分析的研究方法定量研究了广西南部蕨类植物区系内部分化。分别讨论了不同水平距离、不同海拔高度、生境异质性对植物区系组成的影响。揭示了如下规律：从南到北热带区系成分逐渐增多．亚热带区系成分逐渐减少；从低海拔区段到高海拔区段热带区系成分逐渐减少而亚热带成分逐渐增多，并以海拔800m为界；来自石灰岩地区的子区系，其区系成分分布与酸性土地区有差异。
There is heterogeneity in a flora due to distance, elevation and diversity of habitats. In present paper, the differentiation of pteridophyte flora from southern Guangxi was studies quantitatively by clustering analysis approach. The results indicated that: 1 ) the frequencies of tropical distribution patterns increased but that of subtropical distribution patterns decreased from northern to southern; 2) the frequencies of tropical distribution patterns decreased but those of subtropical distribution patterns increased from low elevation to high elevation; 3) an elevation of 800 meters was a line of demarcation; 4) the subflorae from calcareous area were different from those from non w calcareous in compose of distribution patterns.
基金
国家自然科学基金!39203010
39703010
关键词
聚类分析
蕨类植物区系
广西南部
中国
subflora
elevation zone
clustering analysis
pteridophyte flora
southern Guangxi
China
