The Ecological Research In The Wetland Restoration Project In The Eastern Tidelands Of Chongming Island, Shanghai--A Case Of Waterbirds, Plant, Ecological Benefits

As human population increase, the inter-tidal mudflat and salt marshes of the Eastern Tidelands of Chongming Island were reclaimed as large as 8000 hectares during last five years. It results in a decline of waterbird species and population dramatically. The State Forestry Administration and Shanghai Government have given high attention to the issues of wetland restoration of Eastern Tidelands of Chongming Island. Our study is aiming to preserve waterbird and their habitats, which meet the needs of increasing Shanghai's international image on the aspects of nature conservation and species biodiversity. From the point to provide basical research data and feasible advices or measures to the research of Eastern Tidelands of Chongming Island wetland restoration, during November.2002-December.2003, a study on bird communities, plant communities and socioeconomic status was undertaken in the Eastern Tidelands of Chongming Island. The research results are summeried as follows:1. In spring migration period, 55 species of 14,068 birds was observed in the Eastern Tidelands of Chongming Island, the bird density was 47.96 ind./ ha ; while in winter, 56 species of 34,707 birds was observed in the same area, the density was 118.32 ind./ ha . The species biodiversity and structure stability of winter bird communities were greater than the ones of spring's. Data on species and habitat preference of winter waterbirds were collected in each of five habitat types from the intertidal mudflat to that behind the sea wall, which we sampled 5 zones by 2000 m X 100 m transactions. The research results showed that 49 species of 34,504 waterbirds sampled in the five zones from the intertidal mudflat to the fish pounds behind the sea wall, 37 species of waterbird appeared in the algae saline zone, the birds appearance frequency of this zone accounted for 39% of total birds found during the survey; 19 species of waterbird located at the bulrush outer zone with 6% of birds found in the winter; 10 species of waterbird distributed at the bulrush inner zone with 5% of birds found; 4 species of waterbird lived in the reed zone outside the sea wall, only 3% of birds appeared in this area; 37 species of waterbird were found in the fish ponds with reed zone behind the sea wall, the birds appearance frequency reached 47% of total birds found in whole area. Although the waterbirds number of fish poods with reed zone behind the sea wall occupied 17.7% of total number of birds counted in the winter, this area had the highest value of species richness and equality index, this indicated that it is possible to attract waterbirds in the wetland ecological restoration area behind the sea wall.Four samples of waterbird communities and correlated environment factors in the fish poods with reed behind the sea wall were analysed by the methods of Principal ComponentsAnalysis (PCA) and Linear Regression. The results showed that 54 species of 4,270 birds was observed in the total samples in spring, the two principal influenced environment factors were the density of invertebrate and the proportion of water area in the total area; 46 species of 8,226 birds was found in the whole area in winter, the two principal influenced environment factors were the cover of plant and the deep of water. Both in the spring period and in the winter period, the fish poods water conditions, plant cover, the abundance of invertebrate and fish in the fish poods, hunman disturbance had distinctively effects on the species, number, species richness of the waterbirds communities. The optimal environment index to attracting waterbirds in the wetland ecological restoration area in spring or winter was put forward by the above results. We also suggested improving enviornment conditions in order to provide better habitat for waterbirds.2. Owing to the relationship between birds and plant communities, during December 2002 -December 2003, we sampled Phragmites communis distributed outside and inside of the seawall for four seasons in the Eastern Tidelands of Chongming Island, Shanghai.