Abstract: The soil organic carbon(SOC) and carbon storage of Zoigê alpine Kobresia meadows wetland under no water logging, perennial water-logging and seasonal water-logging(during June to October)conditions were studied. The results showed that the SOC of Zoigê alpine Kobresia meadows wetland was extreme high and that in the surface layer of the soil (0-10 cm) reached to 73.2 g·kg^-1, 6-10 times higher than the forest, farmland and grassland ecosystem in China. The vertical distribution reached to 400 cm under ground, which was far more than the forest, farmland and grassland ecosystem in China. There were significant differences (P<0.05) in SOC between shallow soil layer (0-50 cm) and deep soil layer (200-400 cm) over different hydrologic conditions. In the shallow soil layer (0-50 cm) the SOC rank was: perennial water-logging >seasonal water-logging >no water-logging, and in the layer 200-400 cm the rank was: no water-logging > seasonal water-logging > perennial water-logging, while in the soil layer 50-200 cm there was no significant difference in the SOC (P>0.05). In the soil layer 0-400 cm, the C/N ratio of alpine Kobresia meadows wetland over different hydrologic conditions mostly was less than 15, which was beneficial to the accumulation of soil carbon. The carbon storage of Zoigê alpine Kobresia meadows wetland was at a very high level, the soil carbon storage of perennial water-logging, seasonal water-logging and no water-logging was 64.87,71.21 and 76.45 kt·km^-2 respectively, which was 20-40 times higher than the forest, farmland and grassland ecosystem in China. Approximate 60% of soil carbon storage distributed under the 1m soil layer. The total soil carbon storage of Zoigê alpine Kobresia meadows wetland was about 0.245 Pg.

Key words: soil organic carbon, soil organic carbon storage, Kobresia meadows, different hydrologic conditions, Zoigêalpine wetland