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%.

本研究在总面积达27.5万平方千米的柴达木盆地（Qaidam Basin）内布设108个调查样点，采用近网格采样法（near-grid sampling approach）评估了生物结皮（biocrust）的存在情况与盖度。研究结果表明，将调查数据与一系列环境因子相结合后，随机森林（Random Forest）模型可有效估算该盆地内生物结皮的空间分布，其空间分辨率达90米。具体而言，当前柴达木盆地生物结皮总盖度达12.4%，其中以蓝藻、地衣、苔藓为优势类群的生物结皮占盆地总面积的2.0%~5.5%，主要分布于盆地东部与南部边缘地带。生物结皮盖度主要受降水与植被格局调控。预计到2050年，气候变化将使盆地内生物结皮总盖度降低1.0%~2.0%；其中蓝藻与地衣生物结皮的盖度将下降0.5%~1.2%，而苔藓生物结皮的盖度预计将提升0.3%~0.8%。