Invasion and ecological effects of exotic smooth cordgrass Spartina alterniflora in China

Abstract Smooth cordgrass (Spartina alterniflora) was introduced to China in December 1979 to buffer against tides and to accelerate coastal wetland accretion. Since then, its propagation and natural dispersal have allowed this exotic plant to rapidly expand throughout coastal China with generally negative ecological effects. In 2003 S. alterniflora was labeled as an invasive plant in China, and it now covers ~50,000 ha. In this review, we first summarize the mechanisms of spread and spatial distribution of S. alterniflora, and how its physiological characteristics and strong adaptability to the available niche space in China's wetlands have enabled its spread and competition with native plants. Then we review the effects of S. alterniflora on ecosystem function in terms of habitat conversion and the alteration of biodiversity, soil carbon flux and sequestration, and various processes of nutrient regulation. We conclude that we need a long-term and context-dependent perspective, in order to maximize the benefits and minimize the costs of S. alterniflora within each of China's unique provinces.