作 者 ：Hao Si-Jun, Hsu Ping-Sheng, Miao Bai-Mao
期 刊 ：植物分类学报 1989年 6期
关键词：舟山群岛植物区系地理数值研究；
Keywords:The Zhoushan Archipelago, Floristics, Numerical study,
Abstract:
The Zhoushan Archipelago, one of the famous fishing grounds in China, is lo-
cated in the northern part of the Donghai Sea, at the mouth of the Hangzhou Bay (Fig. 1).
The flora of the archipelago was botanically little known. After 1972, several botanical ex-
plorations to the archipelago were conducted by Qiu L.-Q. of the Shanghai Museum of Natu-
ral History, and nearly one thousand numbers of plant specimens were collected. From these
specimens, we have identified about 500 species of seed plants. The present paper deals with a
numerical taxonomic study of the floristic affinities of seed plants of the Zhoushan Archipelago
by means of both cluster and principal component analyses (PCA).
The total distribution realm of the Zhoushan floristic elements is divided into 18 regions,
which were used as Operational Taxonomic Units (OTU). The 348 native species and infrasp-
ecific taxa (see Appendix 1, excluding cultivated plants, ruderals and exotics) of seed plants
were used as characters of the OTUs, A normal cluster analysis using UPGMA gave rise to
phenogram (Fig. 1). The phenogram provides a great amount of information regarding the
floristic affinities between Zhoushan and the other regions. In the PCA, method of inverse an-
alysis was used and has brought forth two diagrams of dimensional program (Fig. 2a,b). These
diagrams give some hints of the distributional trends of geographical elements and floristic af-
finities.
The result of the above analyses shows that the floristics of the Zhoushan Archipelago is
the most closely related to those of its neibouring regions, for instance, Zhejiang mainland, Ji-
angsu and some other regions of eastern China. Though rich in island elements, the archipela-
go has almost no endemic species. The short distance between the archipelago and the mainland,
which has favored mutual exchange of plants, and the severe destruction of the original forest
vegetation, may account for this phenomenon. The floristic similarities between Zhoushan and
Taiwan of China and between the archipelago and Japan are not so remarkable. This may be
due to both the climatical difference and geographical barriers existing between these floristic
regions. Yet the presence of a number of linking plants confined to these floras, such as Rhap-
hiolepis integerrima, Anodendron salicifolium, and Eurya japonica, etc., suggests that these re-
gions should be considered as being of the common tertiary origin.
The mountain forest flora of Zhoushan is more closely related to those of southern regions
than to those of northern regions of China, From the point of view of floristic regionalization,
it is appropriate to consider the flora of the Zhoushan Archipelago as a part of the northern
subregion of the mid-subtropical region.