Abstract: Vegetation is an important biological factor in the ecological succession of wetland, and the main factor affecting the carbon storage and carbon fixation in wetland ecosystem. By the methods of field survey and lab analysis, this paper studied the carbon storage and carbon fixation during the succession of wetland vegetation on east beach of Chongming Island, and the results showed that there existed greater differences in the existing carbon storage and its allocation in wetland vegetation at its different succession stages. The existing carbon storage of the pioneer plant Scirpus mariqueter was much less than that of Phragmites australis, only accounted for about 13% of the latter. The underground rhizome of P. australis and the aboveground part of S.mariqueter were the main sites of existing carbon storage. P. australis at the later succession stage of wetland vegetation had a stronger capability of carbon fixation than S. mariqueter at the earlier succession stage of the vegetation, with the values being (1.63±0.39) kg·m^-2·a^-1 and (0.63±0.28) kg·m^-2·a^-1, respectively, suggesting that during the succession of S.mariqueter community to P. australis community, the carbon fixation capability of the wetland ecosystem became stronger.

Key words: ecological vulnerability, “sensitivity-resilience-pressure” conceptual model, nature reserve., geodetector model