Community Composition And Influencing Factors For Migratory Waterbirds In The Tumen River Basin

Wetland loss and degradation have led to a sharp decline in global waterbird populations,and monitoring and analyzing changes in wetland waterbird community composition and underlying mechanisms is the basis and important prerequisite for waterbird conservation efforts.The Tumen River basin wetlands in Jilin Province are an important stopover sites for migratory birds in Northeast Asia,and most of the studies conducted in the region in the past have focused on the status of wetland loss and ecological quality assessment,while few studies related to waterfowl resources have been reported.In this thesis,127 observation sites were deployed in the middle and lower reaches of the Tumen River basin wetlands,and waterbird surveys were conducted during the spring migration period and the autumn migration period in2021.We analyzed waterbird community composition during the migration season,compared waterbird community diversity in different seasons and types of wetlands,and explored the relative importance of environmental factors and species interactions on waterbird communities in relation to local environmental data.The main findings are as following:1.A total of 47 species of waterbirds in 7 orders and 12 families were recorded in the survey of wetlands in the middle and lower reaches of the Tumen River basin.Among them,Anseriformes were the main group in terms of species and number,bean geese(Anser fabalis)and greater white-fronted geese(Anser albifrons)were the dominant species in the waterbird community in both spring and autumn.4 species of class-I national protected animals,6 species of class-II national protected animals,and 8 species of threatened birds assessed by the IUCN Red List were recorded.2.By comparing the abundance,richness,Shannon-Wiener index,Simpson index,Pielou index and average daily number of waterbird communities in different seasons and different types of wetlands,we found that: waterbird communities differed significantly in time and space;in terms of temporal scale,the abundance,richness and diversity of waterbird communities were higher in spring,indicating that waterbird migration was more concentrated in spring;in terms of spatial scale,the diversity of waterbird communities in different types of wetlands differed significantly,the richness and diversity of waterbird communities in natural wetlands were higher than those in artificial wetlands,and artificial wetlands carried more waterbirds than natural wetlands.3.The joint species distribution model analysis showed that waterbird communities in wetlands in the middle and lower reaches of the Tumen River basin were mainly influenced by environmental factors and species interactions,with spring waterbird communities dominated by environmental factors and autumn waterbird communities probably dominated by interspecific interactions.Different species responded differently to environmental variables,and there were seasonal differences in species’ responses to environmental variables.This study shows that the wetlands in the middle and lower reaches of the Tumen River basin are rich in waterbird resources,and Anseriformes are the main taxa in waterbird community composition;natural wetlands play an irreplaceable role for migrating waterbirds,while artificial wetlands play an effective complementary role in supporting waterbird communities;different factors influence the construction of dominant waterbird communities in different seasons.It is recommended that the management and protection of wetlands in the Tumen River Basin should be strengthened to slow down the degradation and loss of natural wetlands,and that artificial wetlands could be used rationally to give full play to their potential ecosystem conservation role.