Biocrust survey data and biocrust cover maps in the Qaidam Basin

Here, we surveyed 108 sites across the Qaidam Basin using a near-grid sampling approach over 275,000 km² to assess biocrust presence and cover. The results indicated that by combining survey data with a set of environmental factors, the Random Forest model can effectively estimate biocrust distribution in the basin, with a resolution of 90 m. Specifically, biocrusts currently cover 12.4% of the Qaidam Basin, with cyanobacterial, lichen, and moss-dominated biocrusts occupying 2.0–5.5% of the basin, primarily distributed along the eastern and southern edges. Biocrust cover is primarily driven by precipitation and vegetation patterns. By 2050, climate change is projected to reduce biocrust cover by 1.0–2.0%. Cyanobacterial and lichen biocrusts could decrease by 0.5–1.2%, while mosses are expected to increase by 0.3–0.8%.