Abstract: Based on field survey, field-orientation observation and laboratory analysis, this paper studied the soil carbon storage and CO₂ flux under natural forests (Picea crassifolia, Sabina przewalskii, and alpine shrub), artificial larch forest, rangeland, and cropland at the paired plots with same elevation, slope direction, and soil type in the National Nature Reserves of Qilian Mountains. The results indicated that the soil organic carbon (SOC) content under natural forests, rangeland, cropland and larch plantation was 59.45-84.7, 78.30, 13.51 and 43.25 g·kg^-1, mean SOC density was 15.96-19.95, 17.74, 10.63 and 15.97 kg·m^-2, and mean SOC turnover time was 27-36, 25, 23 and 33 years, and the soil CO₂ flux under P. crassifolia, S. przewalskii, alpine shrub, rangeland, cropland, and larch plantation was 584.03, 517.63, 601.00, 796.89, 281.75 and 569.92 g C·m^-2·a^-1, respectively. Under the same vegetation type, SOC content and density decreased with soil depth inereasing, while SOC turnover time was in adverse.

Key words: Lysimachia congestiflora, Light intensity, Clonal architecture, Ramet population characteristics