Wetland ecosystem services research: A critical review

Systematic knowledge of the development, trends, and limitations of wetland ecosystem services (WES) is extremely meaningful for the direction of WES studies and wetland management. A systematic literature review was conducted by collecting 1711 peer-reviewed articles through the Web of Science and ScienceDirect by searching the "topic" domain using the combined keywords "ecosystem service" OR "ecosystem services" and "wetland". The results indicated that current studies focus on WES evaluation, driving factors, wetland management, and policy design, which accounted for 90.9% of the obtained articles. The driving factors are mainly multiple factors, land use change, policy and management, and climate change. Riverine wetlands, multiple wetland types, and lacustrine wetlands are the main wetland types in existing studies, and the evaluated WES types are mainly supporting and regulating services. The applied evaluation approaches mainly include the biophysical and qualitative methods, which accounted for 76.4% and 14.3% of the total studies, respectively. Two main limitations in WES studies are a lack of unified WES evaluation indicators and comprehensive WES studies. In the future, WES research should focus on generating unified WES evaluation indicators for comparison across different studies and up-scaling. Long-term program should be established to gather data for creating ecological production functions to determine the marginal influence of wetland land characteristics on the final WES to refine the management options. Stakeholders should also be involved in the process of designing payments for ecosystem services programs. (C) 2020 The Authors. Published by Elsevier B.V.