望天树林与相近类型植被结构的比较研究

A COMPARATIVE CTUDY OF PHYTOSOCIOLOGY BETWEEN SHOREA CHINENSIS FOREST OF XISHUANGBANNA AND OTHER CLOSER FOREST TYPES

Shorea chinensis forest distributing in Xishuangbanna, S Yunnan, is a forest type of the seasonal rain forest from northern edge of tropical zone of SE Asia. In comparison with various representative tropical rain forest communities, it is indicated that the forest has the same community profile as lowland tropical rain forests, the similar life form spectrum, leaf scale spectrum and leaf type and texture composition to equatorial rain forests, as well as almost the same species diversity, frequency of the tree D. B. H. class and relationship between individuals / species as typical tropical rain forests. With the characters of tropical rain forest, the forest community is evidently belonging to a forest type of tropical rain forest. Because of its distribution in the limiting conditions of climate and altitude the tropical rain forest community of Shorea chinensis forest differs from those in equatorial wet lowland region in the ways that it has some deciduous trees among its upper layer trees, less megaphaenerogamae and epiphytes, more abundant lianas and meso and microphaenerogamae in its life from spectrum, as well as more microphyll in its leaf scale spectrum. Further more, the forest community differs also from those communitites of montane rain forest and lowland monsoon evergreen broad-leaved forest in southern edge of subtropical zone of China in the ways that it has more complex community profile, abundant emergents appearing in the upperest tree layer, rarer hemicryptogamae in its life form spectrum and more chartaceous entireleaves as well as more compound leaves in its leaf texture, margin and type compositon. It is finally concluded that Shorea chinensis forest belongs to the tropical rain forest formation of SE Asia and is a forest type of seasonal rain forest from northern edge of tropical zone. In the vegetation system of China, it is also the forest community closest to wet tropical rain forest.