Abstract: Yancheng coastal wetland is a new world natural heritage site, which mainly focuses on waterbird habitat conservation. The current status and potential problems of waterbird habitat conservation have attracted much attention from scholars. In this study, five major waterbirds habitat sites in Yancheng coastal wetland were selected. Based on the data of three waterbirds guilds, environmental variables and habitat types obtained from field survey, GIS technology, random forest (RF) and threshold indicator taxa analysis (TITAN) were used to identify the suitable habitat of the three guilds and analyze the response threshold of environmental variables. The results show that the shorebirds were mainly distributed in eastern edge of Tiaozini habitat site and Core habitat site, anatidae was mainly distributed in farmland and reed marshes of Tiaozini and Core area, and herons were mainly distributed in aquaculture ponds and reed marshes of each habitat site. The area proportion of suitable areas of antidae in the five habitat sites was smaller than that of shorebirds and herons. T_hab, D_wat, P_fvc, D_ree, D_swa and D_far were the main environmental variables affecting the distribution of the three guilds in suitable areas, covering environmental indicators, such as habitat type, vegetation coverage and distance indicators. There were differences in the number of species in the positive and negative response thresholds of the main environmental variables in three guilds, and the response thresholds of the waterbird guilds to the environmental variables were also different. Finally, some suggestions and schemes for waterbirds diversity maintenance and habitat landscape structure restoration in Yancheng coastal wetland were proposed.

Key words: Yancheng coastal wetland, waterbird guild, suitable habitat, response threshold, landscape structure restoration