Saltmarsh Cordgrass Spartina alterniflora Loisel

Abstract

Saltmarsh cordgrass Spartina alterniflora Loisel, native to North America, is now recognized as one of the most harmful invasive plants in China. Since 1990s, S. alterniflora has successfully invaded the Yangtze River estuary, a globally important eco-region. The invasion has resulted from the plant's abilities to adapt to the estuarine environments and human disturbances. S. alterniflora invasion has multiple ecological consequences to the estuary. The invader out competes native plants such as Scirpus mariqueter and Phragmites australis, and even causes local extinction of S. mariqueter. In addition to changing native soil microbial community diversity and structure, S. alterniflora may carry a fungal pathogen (Fusarium palustre) from its native range which seriously damages native P. australis. S. alterniflora also significantly alters community structure of soil nematodes and macrobenthonic invertebrates, and changes arthropod abundance. Moreover, the abundance of shorebirds is threatened by S. alterniflora-induced changes in food resources and physical habitats. For ecosystem functioning, S. alterniflora invasion increases primary productivity and alters carbon and nitrogen cycling. In the face of challenges, controlling S. alterniflora has been successfully implemented in the Chongming Dongtan of the Yangtze River estuary, but further studies are needed to find an efficient way to control the invasion at a large scale.