Species Diversity and Floristic Characteristics of Vascular Plants in Nanji Island,Zhejiang Provience

A total of 393 species (sub type included) in 267 genera, 97 families were reported in Nanji Island, the main island of Nanji Islands National Nature Reserve. After eliminating all the cultivated and invasive species, there were still 304 species in 210 genera and 81 families belonging to wild vascular plants; To better understand the floristic characteristics of Nanji, we applied analysis in 3 levels: At family level, the largest families in pteridophyte were ranked as Pteridaceae、Thelypteridaceae、Lygodiaceae、Dryopteridaceae; In seed plants, almost the largest ones were Cosmopolitan, while the small ones dominented the most, quantitatively and proportionately; The characteristic families of seed flora were consisted of Liliaceae、Amaryllidaceae、Urticaceae、Verbenaceae, cause they got high ratio of VFICS/WFIW; At genus level, the Pantropical Distribution (3810%)、the North Temperate Distribution (1630%) and the East Asia distribution (1131%) formed the main part of seed flora; The proportion of the category of temperate distribution and tropical distribution was 6072% and 3928% respectively; Took 6 other sites as reference, through cluster analysis and R/T ratio comparisons, It was proved that Nanji Island were most similar to that of Wuyanling of Zhejiang Provience but showed more tropical affinities; At species level, wild seed plants can also be divided into 9 areal subtypes, The Yangtze River & Southern Proviences sub type dominented at 5390%, following by South China sub type at 2078%. The results showed that Nanji Island had a distinctive transitional characteristics of flora from north to south China with more tropical biological properties, thus the floristic division of Nanji should on the southern margin area of east China.