[Relationship between population variation of fig trees and environment in the tropical rainforests of Xishuangbanna].

The species diversity of the plant plays an important role in the ecological environment conservation. In the tropical rainforest of Xishuangbanna the biological diversity is extremely rich, and which is a key region used to biological diversity research. And the fig is a key plant species in the tropical rainforest. The research results about the relationship between the variation of the figs population and environment of the region were following: 1. There were 69 species, variants and subspecies Ficus plant that was known in the tropical rainforest of Xishuangbanna, thereinto there were 23 species and subspecies owned to the Urostigma, and the Pharmacosyea had four species; the Sycomorrus two species and subspecies; while the Ficus owned 41 species, subspecies and variants, then Xishuangbanna borne the most richness and diversity of fig species and numbers in China. 2. The distribution of the figs had intimate connection with the environment, and the species and the quantities showed the most richness in the tropical primary rainforest that was protected well and almost intact, where the figs were mainly to be arbors and giant arbors; and in the devastated stand and secondary forest dwarf arbors, shrubs, bushes and ligneous liana possessed the most in the fig species; while in such regions of tropical rainforest environment that have been destroyed seriously one proportion of the pioneer species of the figs were the main members. 3. Only the key colony of Ficus can be conserved in the tropical rainforest, can the whole ecological environment of the tropical rainforest be protected and rehabilitated, which was one of the important measures to realize it.