Did desertification in China's dunefields intensify or abate during the early little ice age?

Dynamics of desertification in China's dunefields during the early Little Ice Age (LIA, 1300–1540 CE) remain unclear. Using stacked aeolian sand accumulation rates (ASAR) from 32 optically stimulated luminescence (OSL)-dated sections, combined with dunefield extent, sediment grain size, and multiple linear regression (MLR) analyses, we reconstructed desertification processes over the past millennium. Results show desertification abated during the early LIA (average ASAR: 0.21 m century −1 ) compared to the Medieval Warm Period (MWP, 0.34 m century −1 ) and the late LIA (0.43 m century −1 ). Reduced cultivation activities (contribution: 88%), induced by cold-dry climates, dominated this abatement. Intensified cultivation drove desertification in the MWP (73%) and the late LIA (80%), with extreme climates and wars contributing in specific intervals. Our findings highlight human activities as key mediators of desertification, providing critical insights for semi-arid ecological management under changing climate conditions.