中国种子植物区系定量化研究 V．区系相似性

本文总结了应用相似系数即关联系数进行植物区系相似性分析的现状，指出了存在的问题．然后，从集合论角度讨论了区系相似性、相似关系及其相似系数的实质．作者以为在区系相似性分析中应用Ｒ．Ｒ．Ｓｏｋａｌ和Ｃ．Ｄ．Ｍｉｃｈｅｎｅｒ（１９５８）提出的简单匹配系数比较适宜，同时亦能避免以往区系相似性分析中缺乏可比性及某些“表相”相似等问题．最后，还提出了总体相似系数和类型相似系数二个新概念，以便按照吴征镒教授关于中国植物区系研究的学术思想统一研究各个不同地区植物区系的相似性．对此，作者用了６个区系实例进行了演算说明．

QUANTITATIVE STUDY ON SEED PLANT FLORA OF CHINA V. FLORISTIC SIMILARITY

This paper discusses how to use the similarity coefficients, i.e. associationcoefficients, to analyse the floristic resemblance and to resolve problems in comparative study of numerous floras being short of disirable comparison, and in floristic affinity tending to 'phenology" similarity by using improper formula, or neglecting the negative matching shared numbers and so on. The authors take flora similarity in two separate circumstances, narrow and broad similarities, the former points to the normal matching shared numbers of any two floras, and the later, to both the negative and normal matching shared numbers of any two floras. The floristic resemblances, similar relationships and the substance of similarity coefficients from the angle of Set-Theory are discussed. It is considered that the formula of similarity coefficient set up by P. F. Russell and T. R. Rao(1940) is suitable for discussion and determination of narrow similarity, but the simple matching coefficient put forward by R. R. Sokal and C. D. Michener(1958) is suitable for broad similarity. Among them, the formula of similarity coefficient by P. F. Russell and T. R. Rao (1940) is a special form i.e d=0 of the formula of simple matching coefficient by R. R. Sokal and C, D. Michener(1958). The authors suggest two new concepts, one is the similarity in population, and the other, similarity in areal-type, so as to have a unified study of the noristic similarity in different regions separately according to the study of flora in china by Prof. C. Y. wu. In this paper, six floras are used as examples.