A Preliminary Study On Bird Diversity In The Typical Degraded Ecosystem In The Upper Reaches Of Minjiang River

First, a summary is made about recent Chinese study on bird community. The study mainly focuses on two aspects: the structure of community and guild. Many parameters are used to explain the structure of community. There is close relationship between birds and habitat, especially with vegetation, so great attention is paid to forest birds. Many factors have a great effect on bird community, such as elevation, vegetation variation, type of habitat, human disturbance and ecotone. The guild is the result of competition and evolution, which is often classified according to the nesting, the foraging and the behaviour.Secondly, a summary is made about birds used as monitors of environment change. Birds are sensitive to the environment change, even a little. Moreover, birds spread widely and can live in all kinds of habitats. Bird biology and ecology are well known. So birds are often regarded as good indicators of environment change.The common environmental monitoring with birds includes: 1. monitoring one species (individual and population) both in breeding season and non-breeding season; 2. monitoring more species(guild) both in breeding season and non-breeding season; 3. monitoring the whole avifauna (community)both in breeding season and non-breeding season. Individual and population are good indicators of environment pollution, and there are still some questions about the guild monitoring and community monitoring.Finally, We surveyed bird species and relative abundance in three areas of the Upper Reaches of Minjiang River during both summer and autumn. Three areas are Shilixiang whose ecosystem has been seriously degraded, Maoxian Ecological Station whose ecosystem has been restored gradually since 1986, and Shangkakagou whose ecosystem mostly keeps intact. We used several kinds of indices of diversity and the result shows highest diversity in summer community of Maoxian Ecological Stationand lowest diversity in autumn community of Shilixiang and highest evenness in autumn community of Shangkakagou. The result suggests that there is significant difference of bird species composition among three areas. In summer, the species-abundance model of Maoxian Ecological Station is similarly log-series model, the species-abundance model of Shilixiang is also log-series model, and the species-abundance model of Shangkakagou is Random niche boundary hypothesis Model. There is no great change in autumn, only the species-abundance model of Maoxian Ecological Station is geometric-series model. We found the species-abundance model is a good indicator as monitor of habitat change.