In the last decades, the Chongming Dongtan wetlands in the lower reaches of the Yangtze River, one of the important stopovers for migrating waterbirds in the East Asian–Australasian Flyway(EAAF), suffered serious loss, deterioration, and fragmentation caused by frequent large-scale reclamation of intertidal areas, invasion by Spartina, and artificial wetland alterations. The loss, deterioration, and fragmentation of bird habitats resulted in a lack of suitable stopovers for migratory birds. 

Changes in waterbird populations in relation to changes in their habitat are of great concern in stopovers for migrating waterbirds in their EAAF. The spatio-temporal evaluation of the waterbird-habitat relationship not only directly reflects the waterbird population pattern and their habitat quality but also promotes the development of wetland management strategies for protecting migratory waterbirds in the coastal area of the Yangtze River. 

Researchers in the Institute of Subtropical Agriculture, Chinese Academy of Sciences (ISA) employ remote sensing, geographic information systems (GIS) and statistical techniques to analyze the relationship between waterbird population dynamics and the changes in their habitats within the past decades in the Chongming Dongtan wetlands in the lower reaches of the Yangtze River. 

The team found that natural and artificial wetlands were both important to migratory waterbirds during the peak of migration and wintering, and waterbird populations were significantly correlated with their habitat changes both in natural and artificial wetlands. 

In natural wetlands, the species number of Anatidae was positively correlated with the Scirpus habitat but negatively correlated with the Phragmites habitat. The densities of Charadriidae and Laridae were both positively correlated with the deep water habitat but negatively correlated with the Spartina habitat. The density of Charadriidae, however, also exhibited positive correlation with the Scirpus habitat. 

In artificial wetlands, the changes in the density of Anatidae in the winter were negatively correlated with the changes in the areas of aquaculture ponds. 

This research was supported by funding from the Open Foundation of Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences (ISA2015304), the Science and Technology Commission of Shanghai Municipality (10dz1200703, 12231204703) and the Science and Technology Ministry of China (2010BAK69B14). 

The study entitled "Migratory Waterbirds Response to Coastal Habitat Changes: Conservation Implications from Long-term Detection in the Chongming Dongtan Wetlands, China" has been published in issue 1, Vol. 39 of Estuaries and Coasts, details could be found at http://link.springer.com/article/10.1007/s12237-015-9991-x. 

Contact: XIE Yonghong 

E-mail: xyh@isa.ac.cn 

Institute of Subtropical Agriculture, Chinese Academy of Sciences