Ecological\nEffects of the Huge Invasive Species Removal\nProject in Coastal China

Saltmarsh wetlands are recognized\nas some of the most ecologically\nvaluable yet vulnerable ecosystems globally. However, since the 1970s,\nsaltmarsh wetlands in coastal China have been seriously threatened\nby the invasive <i>Spartina alterniflora</i>. Although the\nChinese government has initiated a nationwide <i>S. alterniflora</i> removal project, the potential benefits and risks of this project\nremain unknown. Here, we focus on the Yangtze River Estuary Saltmarsh\nWetland (YRESW) and simulate its future ecosystem structure, function,\nand quality under three scenarios based on remote sensing and field\ninvestigation data. The simulation scenarios include the absence of\na removal project, natural regeneration postproject (NRP), and planted\nrestoration postproject. The results show that the removal project\nwill reverse the escalating invasion trend of <i>S. alterniflora</i> in the YRESW. Compared to the baseline year of 2022, there is a\nremarkable increase in ecosystem structure (composition: +107%, configuration:\n+27%) and ecosystem quality (+10.5%) under the NRP scenario. Although\nblue carbon storage sharply decreases under both scenarios involving\nproject implementation, planted restoration can restore YRESW’s\ncarbon sequestration capacity to 0.19 Tg C per year, achieving 87%\nof the carbon storage present before the project. This study underscores\nthe necessity of comprehensive and detailed risk assessments in ecological\nprojects, particularly when dominant species are involved. Our findings\nhold significant implications for stabilizing coastal wetland ecosystems\nand promoting sustainable development in coastal areas.