Waterbird distribution patterns and environmentally impacted factors in reclaimed coastal wetlands of the eastern end of Nanhui County, Shanghai, China

摘要

The eastern end of Nanhui County is one of the most important coastal wetlands for waterbirds. It is also the key reclamation site in the Yangtze River Delta. In 2005, a reclamation project was completed here. A part of reclaimed area was converted into three types of artificial wetlands: urban lake wetlands; extensive fish ponds; and abandoned wetlands. To examine the effects of different management of these wetlands on the conservation of waterbirds, a study was conducted from 2009 to 2011. A total of 41,493 waterbirds corresponding to 91 species from 15 families were recorded. Two species, Black-faced Spoonbill Platalea minor and Falcated Duck Anas falcata , meet the international conservation Ramsar criterion of >1% of global population size. The extensive fish ponds contain the highest species richness and evenness, followed by abandoned wetlands and urban lake wetlands. Non-metric Multi-dimensional Scaling ordination plot revealed partition with four distinct clusters apparent. The first and the second clusters were positively correlated with deep water area, anthropogenic disturbance, distance to the seawall, and mean water level. The third cluster had no direct relationship with any environmental factors. The fourth cluster was correlated with vegetation area, shallow water area, and bare muddy area.