Abstract: Wetland vegetation is an important part of wetland ecosystems and exerts both direct and indirect effects on underground carbon pools. In this study, we measured the seasonal dynamics of biomass and fine root turnover in Zoige alpine marsh. The results showed that the seasonal dynamics of both aboveground and underground biomass of Zoige alpine marsh showed a unimodal pattern, with the maximum values of aboveground biomass and underground biomass being 518.3 and 2147.4 g·m^-2, respectively. In July, August, and September 2019, underground biomass in the 0-10 cm soil layer accounted for more than 50% of the total biomass in the 0-50 cm soil layer. The maximum value of underground biomass in the 0-10 cm soil layer was found in early September. The average annual turnover rates of fine roots in the 0-50 cm soil layers were 0.795-0.936 a^-1, with the maximum in the 0-10 cm soil layer. The carbon and phosphorus reserves of plants were mainly distributed in the underground part, whereas the nitrogen reserve was mainly distributed in the aboveground part. Our results provide basic support for quantitative assessment of net primary productivity of the Zoige alpine marsh.

Key words: marsh, biomass, fine root, root turnover, element storage.