二滩水电站建成前后库区流域鸟类多样性初步研究

对二滩水库库区的鸟类进行野外调查，发现在水库建成前后的鸟类都是187种，但其种类组成不同，相同种类129种，占观察到的种类的68．98％，同时 发现四川省鸟类新纪录12种，对建成前后的鸟类相对数量和多样性进行对比分析后，发现在水库建成后，云南松林区，常绿阔叶林区和针阔叶混交林区3种生境的鸟为相对数量和物种多样性较建成前增高，均匀度变化不明显，农田耕作区的鸟类物种多样性和均匀度都降低；水库建成后，整个系统的鸟类β多样性略有下降，水域与其它生境的鸟类相似性很低，建成后农田耕作区与其它生境间的鸟类相似性比建成前有所降低，云南松林与另两种森林生境间的鸟类相似性变化不大，常绿阔叶林区和针阔叶混交林区的鸟类相似性增高，导致鸟类多样性变化的一个原因是生境复杂性降低。

BIRDS DIVERSITY BEFORE AND AFTER THE CONSTRUCTION OF ERTAN RESERVOIR

Based on the field survey, there were 187 species of birds in Ertan Reservoir area before and after the construction of the reservoir, in which 129 occupying 68.98% were the same species indicating the compositions were different. There are 12 new recorded species of Sichuan Province. The results showed that after the construction of the reservoir, the relative quantity and diversity of birds in three kinds of habitats i. e. Yunnan pine forest, evergreen broadleaf forest and the mixed forest with conifer and broadleaf were increased but the evenness not changed significantly. The diversity and evenness of birds in fanning lands were decreased. Besides, the B diversity of the reservoir were slightly decreased. The similarity of birds in water area and in other habitats was very low. After the construction of the reservoir, the similarity of birds was decreased between farming lands and other habitats. The change of similarity between Yunnan pine forest and other 2 kinds of forests was not evident but it was increased between evergreen broadleaf forest and the mixed forest with conifer and broadleaf. In addition, the authors analysed and discussed the causes of these changes.