浙江海岛植物区系的研究

A STUDY ON THE FLORA OF THE ISLANDS OF ZHEJIANG PROVINCE

浙江海岛共拥有维管植物１９１４种、１２亚种、１７５变种、２６变型和４６栽培变种，隶属于１９５科、９０９属。植物区系组成复杂，地理成分多样，纬向性明显，与邻近地区有着不同程度的联系，并以地域差异大、热带亲缘特征明显、滨海植物区系丰富和归化植物种类繁多为特色。

There are 3061 islands in Zhejiang, Which located in about 27°05′-30°51′N,120°09′-123°09′E. It is quite rich in species and complex in composition of families and genera.On the basis of investigation in 1990-1993,there are about 1914 species,12 subspecies,175 varieties, 26 fonns and 46 cultivarieties of vascular plant,which belonging to 195 families and 909 genera,The geographic element is complex and varied.According to statistics,702 genera of wild seed plant can be divided into 15 areal-types.Dominant areal-types in the order,are the Pantropic,North TemDerate,East Asia and Cosmopolitan. Besides,it has a very obvious zonal law. The flora of the islands has a various relationship with the neighbouring regions.By compar- ison,it is most close with the mainland of Zhejiang,then with the souther mainland of Jiangsu Province,Souther Japan,Taiwan Province in the species level.Moreover,it has some notable lo- cal distinguishing features as follows.(1)The floristic distribution is disequilibrium in different regions and island types.It is richer in norther region, those islands which near mainland and bigger.(2)It is closely related to the tropical flora. In the genera level, 51.6% of total are tropical distributions.(3)The littoral flora is rather rich,there are 36 genera,135 species(including some coastal psammophytes,halophytes and certain endmic species of island).The latter may be sparated into two distribution types:the hill distribution and the coastal ones,including rocky,sandy and muddy ones.(4)It is much richer in alien plant than the mainland ofZhCjiang.Among which,there are a good taxa belonging to the new record to China,thC Chinese mainland and Zhejiang.