Effects of different vegetation communities on soil carbon and nitrogen contents in Urad desert steppe

This study determined soil carbon, nitrogen contents and C/N of 3 typical vegetation communities in Urad desert steppe. The results showed that: 1) the vegetation coverage of Stipa klemenzii community was significant higher than Achnatherum splendens and Reaumuria soongorica communities (P0.05), while its aboveground biomass was the lowest among 3 communities. 2) the carbon content of 3 vegetation communities was not significant different; but the nitrogen content and C/N of 3 vegetation communities showed significant different, which ranked as A.splendensS.klemenziiR.soongorica and R.soongoricaS.klemenziiA.splendens respectively; 3) Soil organic carbon content of S.klemenzii community was significant higher than the other two communities, especially in 0-30 cm soil layer, and the total soil nitrogen content of R.soongorica community was the highest among 3 vegetation communities in 0-10 cm layer. There were some differences of soil C/N in different types of vegetation, but the change was not consistent with soil depth.