摘要
本文用聚类分析法对取自广西不同地区的30个常绿阔叶林的样地资料进行了分类。样地间相似性的计算采用了Bray-Curtis距离和Euclidian距离公式。聚合策略是用最近邻体法、最远邻体法、中线法、形心法、组平均法、可变组平均法、可变法以及平方和增量法等八种聚合方法。结果证明,用聚类法所划分的类型与按优势种划分的类型既有相似之点,又有不同之处。但是聚类分析法可以对样地进行更为仔细的分离,即不但可把取自不同地区而优势种相同的归为一类,有时还可把它们划分开来;同时也会把优势种不同而地区相同的样地归并到一起。这反映了与地区的纬度、海拔等生境条件相联系的区系组成的变化。根据聚类分析结果把25个样地划分出7种类型,并在其中5类中找出了它的标志种,此外还对8种聚类法和等级划分阈值进行了讨论。
The cluster analysis method is used in this paper to classify 30 releves (292 species) of evergreen broad-leaved forest which collected from different places in Guangxi. The distance formula Euclidean is adopted for calculation of similarity between relevés. Eight cluster methods: nearest neighbour, furthest neighbour, median, centroid, group average, flexible group average, incremental sum of squares and flexible cluster method, are used in cluster analysis.The results of using cluster analysis are similar to, and as well as different with the classification by dominance-type. However, the cluster analysis may differentiate the relevés in more detail. In some cases it can not only incorporate the releves, which come from different places and have same dominants, into same type, but also divide them into distinct groups. Sometimes it can also put the coming from same place and having different dominants relevés together. All of them reflect the floristic composition which relate to latitude and altitude and other habitat factor to be changed. Based on the results of cluster analysis, 25 relevés are divided into seven types and the diagnostic species are sought out of the five types of them. In addition, eight cluster analysis methods and threshold value of classifying levéls are discussed.
出处
《植物生态学报》
CAS
1985年第1期1-20,共20页
Chinese Journal of Plant Ecology
