Spatio-temporal evolution and prediction of desertification sensitivity in the Hulun Buir grassland under future climate scenarios

Desertification ranks among the most serious environmental problems facing human society. What drives desertification in the Hulun Buir grassland? To answer that and improve how we manage it, this study used two tools: the MEDALUS model and the Geodetector method. These helped analyze changes in space and time, plus the factors behind them. Looking ahead, the same MEDALUS model was run with three CMIP6 forcing scenarios (low, medium, high). That gave projections for two future windows: mid-century (2030–2050) and late century (2070–2100). Desertification sensitivity exhibited a decrease–increase–decrease trend during 2001–2020, with a spatial pattern of “low in the east and high in the west”. Precipitation has the strongest inhibitory effect on desertification (β = −0.468), primarily by promoting vegetation growth (β = 0.577) and increasing soil moisture (β = 0.439). Vegetation cover directly inhibits desertification (β = −0.351) and mitigates soil erosion. Temperature affects desertification in two opposite ways: it worsens soil erosion (β = 0.293) on one side, yet also shows a slight direct restraining effect (β = −0.108) on the other. Soil sandification is a key process that intensifies desertification (β = 0.156). How sensitive the land will be in the future depends heavily on which emission path is taken. Under SSP1–2.6 and SSP2–4.5, it goes down, but under SSP5–8.5 it goes up, and the change speeds up over time. This work offers a scientific foundation for stopping desertification and protecting ecosystems in semi-dry areas.