海南岛吊罗山种子植物区系分析

Floristic analysis on the seed plants of Mt. Diaoluo in Hainan Island

吊罗山位于海南岛东南部 ,约 1 8°5 0′N,1 0 9°5 0′E,为北热带地区 ,其种子植物区系共有种子植物1 71科、846属、1 90 0种 (裸子植物 4科 5属 1 0种 ,被子植物 1 67科 841属 1 890种 )。区系分析表明 :(1 )地理成分以泛热带、热带成分占绝对优势 (非世界属总数的 84.2 9% ) ;(2 )纯热带成分不形成区系和植被的表征 ,许多泛热带、热带种类已接近其分布北限 ;山地成分表现出热带、亚热带 -温带成分相互渗透的特点 ;(3 )该区系在海南岛整体区系中占重要位置 ,特有现象较突出 ,有海南岛地区特有属 4个 ,其它中国特有属 6个 ;吊罗山包括邻近的陵水县有 2 3 7个海南岛地区特有种 ,占全部 5 3 6个海南特有种 (变种 )的 44.2 2 % ;吊罗山特有种 5 2个 ,占海南全部特有种的 9.7% ,这表明该区系在海南森林区系中具重要意义。

Mt. Diaoluo,which is situated in North Tropics,consists of 1 900 species,171 families and 846 genera,among its flora,10 species,4 families and 5 genera are gymnosperm,1 890 species(and varieties)and 167 families,841 genera belonged to angiosperm. As a tropical flora,there are some characteristics as follows: (1)It is predominated by pan-tropical,tropical elements(account for 84.29% of total number of genera),and is also strongly affected by abundant subtropical and temperate elements(13.35%). (2)But it is not easy to find the pure tropical genera and species,some pan-tropical and tropical species are close to the northern boundary of their distribution areas; therefore the typical elements of the flora were obviously characterized by the tropical-subtropical and temperate elements. (3)Meanwhile,the flora of Mt. Diaoluo(included in Lingshui County)also contained 4 genera endemic to Hainan,6 genera endemic to China,and 237 species endemic to Hainan(account for 44.22% of the Hainan's flora that has 501 local endemic species and 35 subspecies or varieties),etc. All of these indicate that the flora of Mt. Diaoluo is importance to Hainan's flora.