Abstract: Characteristics of the morphology and biomass distribution of Spartina alterniflora at the maturing stage growing in different tidal flat habitats were in Jiangsu and their influencing factors,and characteristics of the habitats were investigated,analysed and studied.Results show that:(1) the differences between the tidal flat wet land habitats varying from the sea to the land were significant(P<0.05) in biomass,various morphological parameters,leaf biomass ratio,reproductive allocation Ⅰ and reproductive allocation Ⅱ of individual Spartina alterniflora.The variation coefficient of reproductive allocation was highest among all the morphological and biomass allocation parameters;(2) in the habitat where the plant was first introduced,the plants were the longest in growth age and the highest in all morphological parameters(except seed number) and aboveground biomass of individual plants,while in the habitat where Spartina alterniflora population had established just for 1 year,the plant was the lowest in all the morphological parameters and aboveground biomass.The aboveground biomass and morphological parameters were all positively related to the age of the population.Among the biomass parameters,stem length and diameter and leaf length and width were significant in positive relationship with age of the population(P<0.05 or P<0.01);(3) all the morphological parameters(except seed number) were in significant positive relationship with soil organic matter and soil total nitrogen(P<0.05 or P<0.01),which might be one of the important factors causing the differences in morphological characteristics of Spartina alterniflora in different habitats;(4) in most cases,biomass distribution of Spartina alterniflora was insignificantly related to population age and soil environmental factors.The special characteristics of biomass distribution of the plants in specific habitats might be an important reason for Spartina alterniflora to get adapted to and to have successfully invaded the different tidal flat habitats in Jiangsu.

Key words: Spartina alterniflora, morphological characteristics, biomass allocation, tidal flat