Abstract: This research was conducted at Xilamuren in Inner Mongolia on typical desert steppe grassland dominated by Stipa breviflora and Stipa krylovii with the objective of defining the C, N, and P stoichiometry of leaves, litter and soil under two management regimes (year-round grazing exclusion and seasonal grazing exclusion). It was found that: 1) The content of C, N and P in the leaves and litter in year-round exclusion were all greater than in the seasonal exclusion, while the content of soil N in year-round exclusion (2.54 g·kg^-1) was less than that in the seasonal exclusion (2.75 g·kg^-1). 2) The C∶N and C∶P ratios of the leaves in seasonal exclusion was greater than that in the year-round exclusion, which showed that the carbon sequestration ability of the two grasses was reduced under year-round exclusion. However, the soil C∶N and C∶P ratios in seasonal exclusion (4.92 and 36.58, respectively) were less (P<0.05) than those in year-round exclusion (6.03 and 39.80, respectively). 3) The N∶P ratio of leaves were typically greater than 16. Therefore, this is an obvious indication that the two grasses studied were mainly restricted by lack of P at the study site. These results provide scientific data assist decisions on the sustainable recovery management of the desert grassland.

Key words: leanes, litter, soil, ecological stoichiometry, Xilamuren desert steppe