Alxa is a region with severe land desertification and extreme ecological fragility in China. The plantation in the area has effectively curbed the desertification of the local land. However, Studies on soil inorganic carbon（SIC）dynamics after sandy land afforestation are still relatively few. Understanding SIC profiles’ distribution and stock changes after afforestation is essential for assessing regional, continental, and global soil carbon sink potential. Using 5, 11, 22, and 46 years of Haloxylon ammodendron (H. ammodendron) plantations and control sands (MS) in the Alxa region, we studied the variation characteristics of SIC with increasing stand age from 0 to 300 cm. Within the 0-300 cm soil layer, SIC storage increased significantly after afforestation, with 46yrs increasing by 6.52 kg m-2 compared to MS. SIC sequestration rate (CSR) decreased with increasing stand age, in the order of 5yrs（0.054 kg m-2 yr-1）＞11yrs（0.025 kg m-2 yr-1）＞22yrs（0.016 kg m-2 yr-1）＞46yrs（0.009 kg m-2 yr-1）. The 100~300 cm SIC storage accounts for over 60% of the SIC pool. Soil carbon pool estimation will be largely underestimated if only the shallow SIC is considered.

Hippophaerhamnoides is widely known for its important ecological, economic, and social benefits. It is known as the pioneer plant of soil and water conservation, with homology in food and medicine. Here we used occurrence data and environmental (climate and soil) variables to simulate and predict the habitat distribution for H. r. sinensis and H. r. trkestanica in China, both at the current time and in the 2050s (2041-2060). Our aim was to analyze the dominant factors effecting its distribution using MaxEnt and the spatial analysis of geographic information system. The results indicated that H. r. sinensis is mainly distributed in Shaanxi, Shanxi, Sichuan, Qinghai, Gansu, Ningxia, Tibet, and Inner Mongolia, and is mainly affected by bio13 (precipitation of the wettest month), bio11 (mean temperature of the coldest quarte) and bio3 (Isothermality). The suitable habitat of H. r. trkestanica is mainly distributed in Xinjiang, and Tibet, and is mainly affected by bio13 (precipitation of the wettest month), bio2 (mean diurnal range) and bio15 (precipitation seasonality). Although, the two subspecies tend to expand and migrate toward lower latitude under future climate scenarios, there are some differences. H. r. sinensis will migrate westward, while H. r. trkestanica will migrate eastward as a whole. They have a high stability of suitable habitat and are not at risk of extinction in the future. The study’s findings help to clarify the resource reserve of Hippophaerhamnoides L. in China, which will help to guide the protection of wild resources and to popularize artificial planting in suitable areas, and provides scientific basis for the protection of ecological environment.