关键词: 老河故道, 多样性, 长江, 水生生物, 天鹅洲故道

AbstractTrema orientalis forest is an early stage of secondary succession of tropical forest in Xishuangbanna. The relationship between birds and Trema orientalis forest is important to biodiversity conservation and forest regeneration. We used the line transect method to study the structure and function of the bird community in the T. orientalis forest. Within T. orientalis forest, 10 line transects were established, each 100 m long and 10 m wide, to give a total area of one hectare. Within each line, those trees with abundant flowers or fruits were used as focal points for netting birds. Forty five species of birds from seven trophic groups, belonging to 24 genera and 11 families, have been recorded in the T. orientalis forest. All of these bird species ate fruits of T. orientalis except five species of insectivore and four species of seed/insect eaters. The richness of bird species increased with the quantity of T. orientalis fruits. There was also a close relationship between the phenological stages of the T. orientalis and the composition of the bird community associated with it. Furthermore, the parameter of bird diversity ( H′) increased, and the parameter of evenness ( J ) decreased during the peak in ripe fruit abundance of T. orientalis , because the birds were attracted by the fruits and concentrated at those trees that were rich with ripe fruits. Occurrence of insectivorous and seed/insect eating bird species was related to the structure of the forest; they were attracted by insects that feed on the fruits of T. orientali. The T. orientalis forest supports the bird community, and in return, the birds help to pollinate the flowers, disperse the seeds and control insects. As the pioneer trees of T. orientalis are short-lived, after a few years successional woody trees will replace them. Therefore, diverse birds associated with the trees of the orientalis forest may be helpful to natural succession in this ecosystem. It is important to consider the role of birds in the dynamic process of ecological succession.