Ecological restoration of coastal wetlands in China: Current status and suggestions

Abstract

Globally, coastal wetlands have experienced extensive loss and degradation over the past half-century. Ecological restoration is widely recognized as essential for maintaining ecosystem services. China has increased restoration efforts over the past twenty years, but there has been limited understanding of restoration's effectiveness. Through a review of 86 coastal wetland restoration projects in China, we analyzed restoration objectives, restoration measures, funding sources, and restoration effectiveness. We found that quantitative restoration objectives were unavailable from 90.7 % of those projects; active restoration was the primary measure (94.2 %), with vegetation management (40.6 %), topography modification (28.6 %), and hydrological regulation (24.8 %) being the main techniques. Restoration funding came mainly from governments (94.7 %), and the restoration costs per unit area decreased as the restoration area increased. Unrestored wetlands were mainly (75.6 %) used as references for restoration effectiveness evaluation, generally using species diversity (54.7 %) and physicochemical traits (48.8 %) as indicators. Most restorations were deemed as effective (89.5 %). We propose the following for future coastal wetland restorations: setting quantitative restoration targets focusing on protecting threatened species and enhancing ecological services; combining active with passive restoration measures that employ ecosystems' self-healing capabilities; expanding funding sources through diversified stakeholder collaborations; and establishing a comprehensive evaluation system for restoration effectiveness that includes ecosystem functions. This study provides a reference for the design, implementation, and adaptive management of future coastal wetland restoration in China and other coastal countries.