Abstract:To reveal the evolution of C, N, and P contents and ecological stoichiometric ratios along the litter-soil continuum during the restoration of sand-fixing forests, artificial shrub and arbor stands with 25-56 years restoration in the Mu Us sandy land of Yulin were taken as the study object, we measured and analyzed the dynamics of carbon (C), nitrogen (N), phosphorus (P) contents, and their stoichiometric ratios along the restoration years and continuum profiles in semi-fixed sandy sites, from the litter layer to the humus layer and then to the mineral soil layer. The results showed that the C, N, and P contents and their stoichiometry in the two types of woodland at different restoration years were all in the litter layer > humus layer > mineral soil layer. However, the C content of the litter, humus and mineral soil layers increased significantly with the extension of the restoration period, with an average increase of 1.76, 35.70, and 6.45 times compared with that of the semi-fixed sandy land at 56 years; the P content increased significantly in the humus and mineral soil layers, with an average increase of 1.67 and 2.11 times, respectively; the N content increased significantly only in the mineral soil layer, with an average increase of 4.16 times. The change in stoichiometry of the two woodlands showed a significant increase in C∶N in the humus layer with the increase of restoration years, with an average increase of 18.6 times compared with the semi-fixed sandy land at 56 years; N∶P increased significantly only in the shrub continuum; C∶P did not change significantly. Correlation analysis showed that the C content of all layers in the two woodland continuums reached a highly significant positive correlation, and the C of the mineral soil layer was also highly significantly positively correlated with N and P. The C∶N and C∶P of the humus layer were highly significantly positively correlated with the C∶P of the mineral soil layer. In conclusion, the C content of the litter-soil continuum increased synergistically during the vegetation restoration process in Yulin Mu Us sandy land, while the N and P contents increased significantly only in the mineral soil layer, and C∶P was a relatively balanced and stable stoichiometric feature in the continuum.