Spatiotemporal dynamics and influencing factors of soil quality in aeolian desertified lands of the Qinghai-Tibet Plateau

• The SQI minimum dataset includes OM, BD, clay, CaCO 3 , and AvP. • Micromorphology verifies the reliability of soil quality evaluation results. • Soil quality decreases from the southeast to the northwest of the QTP. • SQI declined by 4.2 % in 40 years, while its spatial variability increased. • Key driving factors of SQI include vegetation, precipitation, wind erosion, and land use. Aeolian desertified land (ADL) is widespread across the Qinghai-Tibet Plateau (QTP), posing a significant threat to regional ecological stability. Accurately assessing the spatiotemporal dynamics of soil quality and influencing factors is crucial for ecological restoration and sustainable development. This study analyzed soil quality changes in ADL of the QTP between the 1980s and 2020s and identified key drivers by considering both natural factors and human activities. The results indicate that the soils are characterized by high sand content, alkalinity, and compaction. Nitrogen, potassium, and calcium carbonate (CaCO 3 ) levels are relatively high, whereas organic matter, phosphorus and cation exchange capacity are low. The minimum dataset constructed for soil quality assessment includes organic matter, bulk density, clay, CaCO 3 , and available phosphorus. Over 90 % of sample points are rated between grade III and V on the Soil Quality Index (SQI), indicating generally poor quality and a decreasing trend from the southeast to the northwest. Over the past 40 years, the SQI declined by 4.21 %, with increased spatial variability. Declines are concentrated in the southwestern plateau, especially in the central and eastern Brahmaputra River Basin and southeastern Inner Plateau. The primary factors influencing SQI, by explanatory power, are vegetation cover, precipitation, wind erosion, and land use. Additionally, interactions between these factors have a greater impact on soil quality than individual factors. Soil quality improves significantly when vegetation cover exceeds 60 %, annual precipitation exceeds 53 mm, wind erosion intensity remains below mild, and the dominant land use is grassland or cropland.