Abstract: Saline vegetation in arid areas are widely distributed and the species is numerous, which plays an important role in the ecosystem carbon balance and regional climate regulation. This paper uses the method of combining the field investigation and indoor analysis, Dabancheng saline lake in Xinjiang as the research object, to study the characteristics of carbon density distribution of saline vegetation and soil in arid areas. The results showed that, soil organic carbon density distribution decreased with increasing soil depth, which is between 7.55~15.75 kg·m^-2 within 0~100 cm, average value is 12.54 kg·m^-2, that accounts for 97.84% total organic carbon density of plant community and soil. Black fruit wolfberry and bell thorn are dominant species for saline communities, their ground biomass is 261.38g·m^-2, which accounts for 70.49% of the total biomass. Herbaceous plant community biomass is 109.45g·m^-2 that is significantly higher than aboveground biomass of shrub (84.81±9.22) g·m^-2 and herb layer (79.76±8.61) g·m^-2. Halophytes underground biomass decreased with increasing of soil layer, underground total biomass is 77.74 g·m^-2 within 0~100 cm soil layer. Halophytes total biomass carbon density is 276.48 g·m^-2, ground, litter and underground biomass accounts for 62.09%, 25.75% and 25.75% respectively. The ground vegetation and litter carbon density is significantly higher than that herb, root biomass carbon density distribution in the section, 96.55% concentrated in 0 ~ 50 cm soil layer. The average (it contains underground, ground, and litter) carbon content of halophytes is 43.09%; carbon density by experience conversion coefficient (50%) is higher 13.80% than the actual, which will produce larger deviation in estimating vegetation carbon. Arid saline vegetation, soil carbon density of exploration for plant protection and enhance the carbon sequestration potential in arid areas to provide data support.

Key words: soil organic carbon, soil carbon density, biomass carbon density, saline ecosystem, distribution pattern, Saline lake, Arid area