Afforestation is the primary ecosystem measure to address the issue of ecosystem degradation in in the Horqin sandy region of northern China. However , It is yet unclear how afforestation may affect the recovery of sandy grassland. This study took the ecological stoichiometry as indicators, and conducted a field investigation and indoor analysis to assess the afforestation strategies of three indigenous tree species for the restoration of sandy grassland , three restoration strategies were: (1) grasslands were enclosed via a Populus × beijingensis shelterbelt (FG); (2) Pinussylvestris var. mongolica was used for the afforestation of small, well-distributed grassland patches (MG); (3) Ulmus pumila was used for the afforestation of small, well-distributed patches (UG). Our result showed that the C, N, and P contents as well as the C: N: P ratio in plants, litters, and soils varied significantly between FG, MG, and UG. All three treatments were found to significantly impact the soil ratios of C:N, N:P, and C:P relative to CK treatment after more than 20 years of recovery. The results of N : P in different tissues showed that FG , MG and UG vegetation restorations were N-limited. N and P homeostasis was present in trees, especially Ulmus pumila, while the degree of homeostasis was significantly impacted by afforestation species and plant tissues. The N:P results suggested that lower N deficiency stress may have been experienced by three experimental plants. We concluded that UG was better suited to the dry climate in Horqin Sandy Land.

Global climate change and extensive socio-economic development together decrease ground cover in the semi-arid sandy grasslands of Horqin district in northern China and thereby increase the direct exposure of surface soil to erosion by strong winds—a process that ultimately converts the grassland into a sandy desert. Three ways to restore such degraded lands through afforestation were evaluated in terms of total carbon stored in the restored ecosystems compared to that in the control. Total carbon comprised that stored in the biomass of trees, herbs, and standing litter and in soil (up to a depth of 100 cm). The three restoration treatments were (1) enclosing the grassland within a shelter belt of Populus × beijingensis, (2) afforesting small but well-distributed patches within the grassland using Pinus sylvestris var. mongolica, and (3) similar afforestation using Ulmus pumila. Total ecosystem carbon storage increased significantly in all the three treatments over more than 20 years; at the end of that period, total ecosystem carbon was maximum (104.29 t/ha) in the grassland enclosed by the forest belt, followed, in that order, by afforestation with P. sylvestris (102.96 t/ha), that with U. pumila (92.24 t/ha), and the control (24.48 t/ha). The structure of the plant community created by these treatments is different from that found in natural stands of forest and in grasslands without trees or shrubs, and all the three treatments are suitable for restoring the moderately desertified sandy grasslands in south-eastern Horqin, northern China, depending on the availability of water and soil nutrients.