To clarify the distribution characteristics of soil organic carbon （SOC） and its influencing factors under different grazing intensities in a typical Inner Mongolian grassland， this study measured and analyzed SOC， total carbon （STC）， total nitrogen （STN）， total phosphorus （STP）， soil water content （SWC）， soil pH， soil bulk density （SBD）， and aboveground biomass （AGB） across the 0-50 cm soil layers under no grazing （CK）， moderate grazing （MG）， and heavy grazing （HG） in Zhengxiangbai Banner， Xilingol League， Inner Mongolia. Key results included： SOC content decreased with soil depth under all grazing intensities， with the highest SOC content observed in the 0-10 cm layer. From 0 to 50 cm deep layers， SOC declined by 7% （CK）， 17% （MG）， and 8% （HG）. Moderate grazing significantly increased SOC content in the 0-30 cm layer， with the greatest increase （11%） in the 0-10 cm layer （from 35.33 to 39.45 g·kg^-1）. Grazing effects on SOC diminished with soil depth， showing weaker impacts on deeper layers.Grazing intensity altered SOC-environment relationships： SOC was primarily driven by AGB and SWC under CK， shifted to interactions with soil nutrients （STN） and physical properties （SBD， pH） under MG， and strongly correlated with STC， STN， STP， and SBD under HG. The study concludes that moderate grazing enhances SOC accumulation and transformation in the short term， while heavy grazing poses a risk of carbon loss despite no significant SOC reduction. Protecting surface carbon pools through controlled grazing intensity is critical for sustainable grassland management.

Typical Grassland  /  Grazing Capacity  /  Organic Carbon  /  Soil Physical and Chemical Properties