Secondary succession characteristics of vegetations on reclaimed land inside Chongming wetland seawall

National reserve Chongming Dongtan wetland was designated as an important international wetland (ramsar site) in 2002. The area outside 98 seawalls is the core area of the reserve, while their inside is the experimental area. A wetland restoration project was started in June 2003, and a large pond behind the seawall was unwatered, which changed the soil condition and appeared drought and salinization. The vegetations presented typical secondary succession, and Aeluropus littoralis and Suaeda glauca invaded the area originally dominated by reed. From July 2003 to April 2004, the soil moisture content and salinity of 15 samples were determined, with the biomass, height, density, and coverage of each kind of vegetations measured. The results showed that the vegetation layout had become an obviously zonary distribution of Aeluropus littoralis-Aeluropus littoralis/Suaeda glauca-Suaeda glauca/Phragmites communis-Phragmites communis community. Suaeda glauca gradually extended to the reed area, and became the dominant species of the area, with an average biomass of 2003 415.4 g·m^-2 in autumn, and of 2004 391.53 g·m^-2 in spring. The biomass and height of Suaeda glauca increased, and its density was getting stable, suggesting that the plant had strong growth ability in drought area.