中国主要侏罗纪植物群相似性系数的初步研究

Preliminary Analysis on the Similarity Coefficient Study of Representative Jurassic Floras from China

选取属级分类单元作为统计变量,Dice系数作为统计公式,对中国早中侏罗世较具代表性的18个植物群进行了相似性的聚类分析。研究结果显示出的区系划分格局在一定程度上支持了前人对植物群时代和性质的判断,同时提出香溪组、万宝组所含植物群的特殊组合与时空因素值得深入研究；中国北方早侏罗世植物群、北方中侏罗世植物群以及南方早中侏罗世植物群三者之间的差异、联系及范围界限需要进一步深入研究。本研究是对古植物学区系研究的有益探索,为中国侏罗纪植物群的大区域系统研究提供了数据基础和参考依据。

We report the study of the similarity of 18 representative floras of the Lower and Middle Jurassic from China by use of clustering analysis. The statistical results generally support the previous recognition of floral aspects and geological ages by palaeobotanists （i.e., the Jurassic flora from China could be divided in general into southern and northern palaeophytogeographic provinces）. The present analysis suggests differing opinions about some flora. This investigation provides further statistical evidence for systematic study of the Jurassic floras from China on a regional scale.