Abstract: From April to December 2005, an investigation was made on three main types of wetland plant community composed of Scirpus mariqueter, Spartina alterniflora, and Phragmites australis, respectively in the lower shoal of Jiuduansha at Yangtze River estuary, with their plants sampled monthly, and the N, P, and K contents and biomass determined. The three species had different characteristics in their N, P, and K contents, distribution, storage, and dynamics, and the nutrient contents in different species and in different organs of same species differed with plant growth. The order of N, P, and K contents was obviously different in different species and in different organs of same species. The storages of N, P, and K were mainly affected by plant species, their organs, and biomass, among which, biomass was the main limiting factor. The nutrient contents and storages of the three species and their organs were generally lower in lower shoal wetlands than in upper shoal wetlands. The nutrient contents of the plant species showed obvious seasonal dynamics, i.e., higher at the initial stage of plant growth and lower at the withered stage. The dynamic characteristics of N, P, and K contents differed with plant species, but had an overall tendency of decreasing with plant growth and in the order of K>N>P. Under the effects of local environmental factors, there existed differences in the characteristics and patterns of  N, P, and K contents, distribution,storage, and dynamics in the wetland plants between lower and upper shoals of Jiuduansha.

Key words: Balsam pear, Zinc and boron, Yield and quality, Polyamines, Hormone, Active oxygen metabolism