2005-2021年沉湖湿地水鸟群落动态及其对景观格局变化的尺度响应

[Objective]As key taxa in wetlands ecosystems and indicator species of wetlands ecosystem environments,waterbird play an important role in maintaining the health of Wetlands ecosystems.As one of the important lakes along the migration route of waterbird between the middle and lower reaches of Yangtze River and East Asia-Australia,the Chenhu Wetlands is a wintering site,breeding site or resting place for a variety of endangered and rare waterbird.Land use changes in the sub-basin of the Chenhu Wetlands may have had a profound impact on the structure of the waterbird community.To investigate the waterbird community dynamics in the Chenhu Wetlands and to reveal the response of waterbird community dynamics to changes in landscape patterns at different spatial scales,this study combined the waterbird observation data of the Chenhu Wetlands from 2005 to 2021,remote sensing images and analyze the relationship between waterbird community dynamics and landscape pattern dynamics in the Chennhu Wetlands from 2005 to 2021.The main results are as follows:(1)The number of species and individuals of waterbirds in the Chenhu Wetlands increased substantially between 2005 and 2021.Winter migratory birds are the mainstay of the waterbird community;wading birds are generally the dominant taxon in the ecological composition of the waterbird community,and the number of individuals is mainly composed of wading birds;omnivorous waterbirds are the dominant group of feeding species,and the composition of the number of individuals changes from no obvious dominant feeding to phytophagy;Geese and Plovers are the dominant order in waterbird communities;the number of dominant species in the waterbird community gradually decreased after 2015.The species diversity index of the waterbird community fluctuated up.The waterbird community experienced two stages of drastic change in species composition and less change in species composition.(2)The number of species and individuals of winter migratory birds in the Chenhu Wetlands increased substantially between 2005 and 2021.Wading birds were generally the mainstay of the ecotype composition of the winter migratory bird community;the composition of dietary species was mainly omnivorous,the number of individuals was dominated by phytophagy;Geese and Plovers were the dominant species in the composition of winter migratory bird communities;the dominance of goose and duck populations is increasing.The species diversity index of the winter migratory bird community fluctuated upward;the species composition of the community changed less and less,and the species composition was relatively stable.(3)Endangered and rare waterbirds were observed in the Chenhu Wetlands each year from 2005 to 2021,the number of endangered and rare waterbird species began to increase steadily after 2017.After 2018,endemic waterbird species were observed every year.(4)At the scale of the Chenhu Wetlands Nature Reserve,the natural wetlands landscape type in shallow water is the main positive driving factor for the increase in species diversity,species number and individuals of waterbird communities;at the scale of the periphery of the reserve and the sub-basin,it is transformed into artificial wetlands landscapes such as aquaculture ponds and root/rice fields.The driving factors of waterbird community dynamics changed significantly at different spatial scales.