Abstract: The biomass dynamics of Spartina alterniflora at its sexual propagation stage in Shankou mangrove reserve of Guangxi, China was studied from June to November 2007. The results showed that at the beginning of the sexual propagation stage of S. alterniflora, the biomass of different vegetative organs increased over time, while at late propagation stage, the growth rates of root, stem, and leaf biomass were all negative, and the negative growth rate of stem was caused by the negative growth of root and leaf. The underground biomass was far less than aboveground biomass, and the biomass of different organs was in the order of stem>leaf>root>reproductive organs in all months except June. The proportion of root biomass to total biomass was decreased from 28.9% in June to 14.0% in November, and the biomass of reproductive organs only took a small part in the total biomass and increased with time.

Key words: No-tillage plus inter-planting, Straw-remaining on field, Wheat, Cropland eco-environment