Effect evaluation and management strategies for freshwater restoration projects in Yellow River Delta Wetlands

The ecological restoration projects, implemented annually by transferring amount of water from Yellow River to its delta wetlands since 2002, has replenished the vital freshwater resource, reconstructed the flow regimes, and improved on wetland’s structure, functions, and key ecological process remarkably. In this paper, focusing on the three restoration areas (R2002, R2006, and R2010), we have systematically assessed the restoring effect since the freshwater projects are implemented by using literature review, data collection, and mathematical statistics. From the results, the soil water content increased significantly, and the salt in sediments decreased greatly among the three restoration area (p<0.05); and the implementation periods enlarge the extent of variations. The biomass, species richness, and diversity of the microbenthic community in R2002 and R2010 are better than that of in R2006 (p<0.05). The vegetation in R2002 and R2006 improved significantly (p<0.05), but not in R2010 due to the lack of the effective monitoring data. Further, we have put forward four countermeasures and suggestions to the wetland managers, including the recovery of the mimic natural flow regimes for the estuary wetland, the construction of the soil-water-vegetation habitat pattern for the livable birds; the establishment of the long-term mechanism for water resources supply; and the development of the adaptive management for the freshwater restoration projects.