Abstract:

Smooth cordgrass,〖WTBX〗Spartina alterniflora〖WTBZ〗 Loisel.,a perennial rhizomatous grass native to the Atlantic and Gulf coasts of North America,has invaded into many estuaries and coastal salt marshes in China in the past 20 years.Chongming Dongtan(“Dongtan” in abbreviation),the wetland of international importance,which provides important stopover sites for migratory birds on East AsianAustralasian Flyway,has been suffering from 〖WTBX〗S. alterniflora〖WTBZ〗 invasions in the recent 15 years,and the structures and functions of the wetland ecosystem were severely threatened.〖WTBX〗S.alterniflora〖WTBZ〗 was first recorded in Dongtan in 1995 and kept expanding rapidly in the latter decade.The 〖WTBX〗S.alterniflora〖WTBZ〗 communities covered 1 600 hm2 by 2005,which distributed dominantly in the northern and eastern marshes in Dongtan.Based on recent studies,this paper illustrated the mechanisms of successful invasions of 〖WTBX〗S.alterniflora〖WTBZ〗.According to the physiological characteristic of 〖WTBX〗S.alterniflora〖WTBZ〗 and the hydrological characteristic of Yangtze River mouth,it can be concluded that:1)〖WTBX〗 S.alterniflora〖WTBZ〗 would keep expanding in the northern and eastern Dongtan;2) It would be difficult to be invaded for 〖WTBX〗S.alterniflora〖WTBZ〗 in southern Dongtan;3) Human activities would facilitate 〖WTBX〗S.alterniflora〖WTBZ〗 invasions.Consequently,proper management and control of 〖WTBX〗S.alterniflora〖WTBZ〗 should be carried out urgently