海南种子植物科属与邻近地区科属关系的初步研究

A PRELIMINARY STUDY ON THE FLORlSTIC RELATIONSHIPS BETWEEN HAINAN AND ITS ADJOINING REGIONS

一、前言 本文以海南野生种子植物的科属与越南、菲律宾、澳大利亚和我国台湾,广东(雷州半岛)等地的植物科属统计数字和属相似性,试图探讨它们之间的相似关系,对今后引种驯化和研究华南植物区系有一定的参考作用。

The flora of Hainan is very rich. There are about 2784 species belonging to 1106 genera and 199 families, about 66.1% of the total families, 37.1% of the total genera and 11.2% of the total species of China respectively. Of the 1106 genera only 93 are not found in Vietnam; the rest 1013 genera or 90.6% are common to both areas. In Philippines, 873 or 78.9% out of 1309 genera are found in Hainan. The near by continental Guangdong has 775 or 70.07% genera common to this island and Taiwan has 656 or 59.31% of her indigenous genera being found in Hainan. Australia, which is further away, with only a few genera are common to both areas.Based on the above mentioned facts the floristic characteristics of Hainan can be concluded as follows. (1) It is abundant in archaic, apocarpous and polycarpous genera and families but Gymnospermae and relict species are rather few.( 2 ) Pantropical and tropical genera and families are dominant; subtropical elements are lesser and temperate elements are the least.( 3 ) The diveasity of species is rather poor. In the 1106 genera, there are 551 genera with 1 species, 308 genera with 2 - 5 species and 236 genera with 6 - 19 species. The genera with more than 20 species, such as Syzygium, Desmodium, Lithocarpus, Quercus, Ficus, Ilex, Symplocos, Ardisia, Hedyotis, Cyperus, Fimbristylis, Carex are mostly widespread genera.( 4 ) widespread and cosmopolitan species and genera are abundant. Out of 1106 genera only 6 are endemic oceupying 0.54% of the total. Out of 2784 species, 395 are endemic occupying 14.19% of the total. In comparison with the flora of its adjacent regicns, ( 38% of species of Vietnam, 74% of species of Philippines and 40% of species of Taiwan are endemic, the proportion of endemic species in Hainan is rather low. )The factors of the characteristics mentioned above are many, besides the effacts from different geographical and ecological condition, the movement of the earth makes certain influences.