The Avian Biodiversity Conservation And Habitat Optimization In Wetlands Restoration In Dalian Lake, In Shanghai

The scientific restoration on the deteriorated lake wetlands is one of the hot topics in ecological research. Most Shanghai lake wetlands are located in Dianshanhu multi-lakes area in western suburb, which is center around Dalian Lake. This area is part of the water source region of Huangpu River with abundant wetland resources and high-level biodiversity, where the birds'type and quantity has reached the international standard of important wetlands. However, the abuse of land and water resource in Shanghai lake wetlands leads to serious ecological problems, which brings about safety hazard to the regional water supply and becomes the limiting factor to this coordinated growth.To cope with the problems above, "Shanghai West Qingpu district planning (2005-2020) (draft)" explicitly located the ring Dianshan Lake 203.3km2 area orientation in Shanghai's biggest water reserves and ecological conservation areas, and proposed the wetland restoration design, focusing on Dalian Lake, as the first scheme. The planning region's area is 14.6km2, and the first phase of the project area is located in the northeast of Dalian Lake. Based on this wetland restoration project, we selected the birds, the most active and striking part, as our research object to evaluate the effect of wetland restoration, and then put forward the key species'conservation strategies and optimization method of habitat.The main content as follows:1. Avain diversity investigation in the planted area of wetlands park. From December 2009 to March 2010, an investigation was made on avian communities in four major habitats,i. e., natural wetlands, artificial wetlands, farmlands and woodlands in planted area, with related diversity indices analyzed. A total of 72 species belonging to 11 orders and 28 families was recorded. The significant difference was presented among the avian communities of the four habitats in Shannon-Wiener index (H'). Farmlands has the highest dominance index (C), followed by natural wetlands while no significant difference was found in that between artificial wetlands and woodlands. The Pielou index (J) of woodlands was significantly higher than other habitats and that of farmlands was lowest, while no significant difference was found between natural wetlands and artificial wetlands. Woodlands has the highest species richness and no significant difference was found in richness among the other there habitats. The similarity index (S1) of avian community of natural wetlands-artificial wetlands was the highest while that of artificial-farmlands area avian communities was the lowest, and the Bray-Curtis (CN) index of avian community of artificial wetlands-woodlands was the highest while that of farmlands-woodlands area avian communities was the lowest. Inter-habitat's heterogeneity and human activities were the main factors affecting the characteristics of avian community in Dalian Lake wetlands. Habitat fragmentation and illegal hunting hold negative impacts on the avian community.2. Avian diversity in the engineering experimental region. From December 2008 to June 2010, a tracking investigation was carried out on the birds and the environmental factors, in which bird index and environmental factors were recorded divisionally. A total of 134 species belonging to 13 orders and 34 families was recorded, which is accounted for 29.25% of the total number of the birds in Shanghai and 57.38% of the total number of the birds in Dianshan Lake area.14 new species were recorded after the construction, in which Halcyon smyrnensis is a new record in Shanghai. There was not significant trend in the bird diversity because of the reasons and the construction. The single land utilization way, inappropriate water area ratio, excessive water depth, inapposite vegetation arrangements, unreasonable proportion of bare mudflat and proportion of barren and heavy human disturbance are all the factors which influencing the bird diversity.3. The effects of restoration in the engineering experimental region. The increase both in the species and number of anatidae showed that the large water area in the engineering experimental region had could attract the anatidae. Some areas have not completed the terrain shaping and vegetation fostering which resultes the rise and fall in the number of waders. There is a downward trend in the ardeidae which is caused by the aquaculture ponds being replaced by the ecological ponds. On the whole, there is upward trend in all the birds and initial success of wetland restoration.4. The avian habitat optimization. The main conservation proposals as follows:wate level should be one important consideration because the change in water level is related to the proportion of the water and the proportion of bare mudflat. For the waders, habitat needs to containe three kinds of landscape element, which is body of water, vegetation and bare flats. Human disturbance should be under a low level. The aquaculture ponds, which could provide foraging habitat for large amount of birds, should be reserved properly.