Abstract:During the 21st century, economic development, urbanization and global climate change have caused the degradation of wetlands. This global problem has become a major research focus of present wetland science. Wetland degradation was also the main topic of the international wetlands conference held nearly 10 years. Research on wetland degradation has rapidly developed to form a large body of work; however, a unified theoretical framework has yet to emerge. There are still many questions that should be investigated, even if there is no uniform concept of wetland degradation. In China, study of wetland degradation has developed relatively slowly, and there has been a lack of quantitative, in-depth research. In this paper, we discuss the concept of wetland degradation and review the recent advances that have been made in wetlands degradation research in nine areas: wetland degradation standards, degradation characteristics, classification of degradation, degradation process and mechanism, index system for degradation monitoring, index system for degradation assessment, new technology for degradation monitoring, ecological restoration theory and technology of degraded wetlands. We also analyze current problems of wetland degradation in China and propose areas for future research. The findings from research show that the process and mechanism of wetland degradation arise from synergistic impacts of multiple stress factors. This includes climate change impacts on biogeochemical wetland processes, especially the nutrient cycling process, and on hydrological wetland processes at the catchment scale, particularly from rising sea levels. Theory and practice of wetland management for restoration and reconstruction, wetland degradation assessment and monitoring technology, wetland degradation assessment indexes and identification of stress factor intensity thresholds during wetland degradation have all been active areas of current research. Limitations of the present research on wetland degradation research in China include lack of deep understanding of the wetland degradation process and mechanism, imbalance in research intensity among geographic regions, failure to use modern research methods, lack of communication among researchers, lack of advanced theory and practice of degraded wetlands restoration. Accordingly, we suggest wetland degradation research should have the following aims: 1) to strengthen long-term, systematic study of wetland degradation; 2) to investigate the processes and mechanisms of wetland degradation, specifically using quantitative methods; 3 ) to encourage sharing of information and academic resources; 4) to strengthen basic research of degraded coasts, estuaries, lakes and plain wetlands and develop detailed theories and methods so as to play their exemplary role to the outlying geographic regions; 5) to apply the latest technologies; 6) to enhance communication with other disciplines; 7) to investigate the mechanisms of changes in biogeochemical processes of degraded wetland arising from the impacts of climate change and human disturbance; 8) to strengthen research on the sustainable use of wetland ecosystems; 9) to strengthen research on hydrological processes of degraded wetlands at the watershed scale; 10) to strengthen research on wetland degradation assessment; 11) to research important technologies for wetland restoration. We aim to promote wetland conservation, and stimulate research on wetland degradation and restoration as well as scientific management of degraded wetlands in China.