EFFECTS OF THE ENVIRONMENTAL STRUCTURES ON BIRDS IN URBAN AND SUBURBAN AREAS OF BEIJING
北京城市及近郊区环境结构对鸟类的影响

The relationships between bird communities and urban and surburban environmental structures of all seasons in Beijing are studied by using the Strip Transect method and the IP A method to estimate the relative densities of birds. The environmental structures are described in terms of area and spatial heterogeneity, and the la-tier is consisting of naturalness and environmental diversity. The numbers of bird species and bird species diversity vary with the spatial heterogeneity in which naturalness is more important than environmental diversity in their effacls on bird communities."Edge effect" should be due to the environmental diversity. The effect of area on the numbers of bird species is obvious if the spatial heterogeneity is diverse. There are only a few of dominatants in the various bird communities because of the lower heterogeneity of urban environments. In order to improve the urban environmental structures, it is recommended to increase the areas, layers and species compositions of vegetation, as well as various kinds of waters in the urban area of Beijing metropolis.