西双版纳热带雨林植物区系的特点

THE FLORISTIC CHARACTERISTICS OF THE TROPICAL RAINFOREST IN XISHUANGBANNA

西双版纳热带雨林植物区系种子植物估计有3000多种,隶属于1000多个属和大约180个科。区系成分是热带科、属和种分别占总科、属和种数的80%、94%和90%以上。在热带分布属和种中,又具体以热带亚洲成分占优势。结论是该植物区系属于热带亚洲区系的一部分,并带有热带边缘性质和几种地理成分交汇的特点。

The tropical rainforest in Xishuangbanna is estimated to consist of more than 3000 species of seed plant pertaining to more than 1000 genera and about 180 families. Based on the comprehensive analysis of the distribution of taxa in two representative communities of the rainforest, the deduction is given as follows: the families, genera and species off tropical distribution take up about 80%, 94% and more than 90% of the total of the flora respectively; of which the genera and species of tropical Asia take up 33%-42% and about 74% of the total respectively. The flora is explicitly of tropical in nature and as a part of tropical Asian flora. Oceured at the montane habitates of northern margin of tropical SE Asia, the flora also embodies conspicuous characters of marginal tropics. Xishuangbanna is geographically a transitional area from true tropics to subtropics and an ecotone where several floristic elements, such as that of Indo-Malaysia, that of S Asia or S Himalayas, and that of Indochina-S China and S China mingle. The flora is therefore endowed with the characteristics of floristie ecotone.