New Progress on the Evaluation of the Suitability of Overyearing Waterfowl Habitats in Poyang Lake Wetland
As an important part of the service function of the ecosystem, the maintenance and strengthening of the supervision and protection of biodiversity in key regions is critical for the sustainable development of regional ecological safety and economic society. In recent years, as people are more aware of the protection of biodiversity, the living environment of typical wetland waterfowl and their health status are continuously catching the attention of the academia. Human intensified development will change the environment of waterfowl habitats and cause the structure and function of wetland ecosystem to be disturbed by the outside, threatening the suitability of the overyearing waterfowl habitats. Therefore, it is important to maintain and restore the stability of wetland ecosystem, protect wetland waterfowl effectively, and analyze the impact of the time and space changes of land structure in the long-term on the wetland waterfowl habitat by combing multiple technologies and disciplines.
Poyang Lake is the largest freshwater lake of China and also is the largest and most important overyearing waterfowl habitat in the middle-low reaches of Yangtze River and even East Asia. However, in recent years, the time and space changes of the land structure in Poyang Lake region are extremely huge because of the climate change, the construction of Three Gorges Project and other human activities, which will definitely change the layout of waterfowl migration and habitats. Therefore, the young researcher of our institute, Tang Xuguang, and other researchers, by using remote sensing and GIS as the technical supports, and considering the environmental characteristics, established the evaluation system for the suitability of waterfowl habitats in Poyang Lake wetlands, with evaluation indicators including the water resources status, interference conditions, food richness, and land use. Based on this, from 1995 to 2005 and till 2014, they have performed three dynamic reviews on the impact of the time and space changes of the land structure on Poyang Lake wetland waterfowl habitat in 20 years, providing scientific basis for the protection of biodiversity in Poyang Lake region and the improvement of ecological environment. The previous investigation data of waterfowl (1997~2013) shows that overyearing water-birds, ducks and geese have the highest percentage and this kind of waterfowl mainly feed on grass. Therefore, this research selected typical habitat indicators on the basis of choosing ducks and geese as the researching object. In addition, they collected the transportation map of Jiangxi province of the three periods and studied the information of high-speed railway, railway, highway, main road (national road and provincial road) and secondary road (town and county road) and established an accurate weighting system. The research shows that for a long time, the water area keep shrinking in the dry season while the area of wetland and grass has increased a lot. Additionally, the “Land to Paddy” project of Jiangxi province also provided more suitable habitat for overyearing waterfowl. In 1994, the Three Gorges Project started. In 2003, it stored water for the first time. Till 2012, the water level reached the expected level (175m). The time period of this research matched the above three time of the project, which was also another diagnosis of the potential environmental effect of the project. Besides, the research also pointed out that the waterfowl habitat is just one part of ecological system service. The comprehensive decisions and improvement of service function still need to be coordinated with other supply and adjusting functions.
The research was supported by National Natural Science Foundation of China and the opening fund of the key laboratory of the researching education department of Poyang Lake wetland and catchment. The researching results are published on the mainstream journal of environmental science "Science of the Total Environment “(IF4.009).