Abstract:

In this paper, the phytocoenological method is used to analyse the species structure of the Pometia tomentosa community, a tropical seasonal rain forest community in Xishuangbanna area. The component structure can be devided into five layers, i.e. three tree layers, one tree-shrub layer and one herb layer. There are total 81 tree species with over 2.5 cm in diamter breast high(DBH). The important value index(IVI) of these trees is got through caculation.6 spe-cies of the trees are dominent species by comparing IVI with other species, and Pometia tomentosa is the most dominant species in the community.77 tree-shrub species.21 herbs, 43 lianas and 5 epiphytes are also recorded in the 25 quadrats which are 2x2m (4m2) large in area.

Key words: Xishuangbanna, Seasonal rain forest, Pometia tomentosa community, Component-structure