西沙群岛植物资源调查

Investigation of plant resources in Xisha Islands

西沙群岛主要的植被类型是常绿珊瑚岛林、灌木林或滨海植被。本区有植物89科224属340种,其中大型真菌6科11属22种,地衣1种,蕨类4科4属5种,被子植物78科208属312种。根据其经济用途,划分为10个类型,主要资源植物有药用植物、蜜源植物、食用植物、观赏植物等。西沙群岛的植物区系与海南岛十分相似,属、种的相似性指标分别为98.46％和94.09％。泛热带分布的属是本区系中最大的部分,占总属数的70.00％。最后对西沙群岛植物资源的保护和利用进行了讨论。

Xisha Islands is situated in the South China Sea, at 111?1'~112?4' E. and 15?6'~17?08' N. , with an altitude of 2. 6~15. 9 m. The major types of vegetation are the evergreen coral island forest, scrub forest and beech vegetation. There are 340 species of plants belonging to 89 families and 224 genera in this islands, of which there are 6 families, 11 genera and 22 species of Macromycetes, only 1 species of Lichen, 4 families, 4 genera and 5 species of Pteridophytes and 78 families, 208 genera and 312 species of Angiosperms. According to economic uses, we may classify them into 10 types, of which there are 15 species of timber plants, 78 medicinal plants, 24 oil plants, 10 aromatic plants, 49 nectariferous plants, 28 fibre plants, 62 edible plants, 70 ornamental plants, 3 starch plants and 3 tannic plants. The flora of Xisha Islands is quite similar to that of Hainan Island, the similarity indices of genera and species are 98. 46% and 94. 09% respectively. The Pantropic genera in the flora are the largest part, amounting to 70. 00% of total genera. The conservation and utilization of plant resources are discussed.