The Qaidam Basin of the Qinghai–Tibet Plateau is a cold, hyper-arid desert that presents extreme challenges to microbial communities. As little is known about variations between surface and subsurface microbial communities, high-throughput DNA sequencing was used in this study to profile bacterial communities of the soil samples collected at different depths in three regions in the Qaidam Basin. The α-diversity indices (Chao, Shannon, and Simpson) indicated that bacterial abundance and diversity were higher in the east and the high-elevation regions compared to the west region. In general, Firmicutes was dominant in the west region, while Proteobacteria and Acidobacteria were dominant in the east and the high-elevation regions. The structure of the bacterial communities differed greatly across regions, being strongly correlated with total organic carbon (TOC) and total nitrogen (TN) content. The differences in bacterial communities between the surface and the subsurface soil samples were smaller than the differences across the regions. Network analyses of environmental factors and bacterial genera indicated significant positive correlations in all regions. Overall, our study provides evidence that TOC and TN are the best predictors of both surface and subsurface bacterial communities across the Qaidam Basin. This study concludes that the bacterial community structure is influenced by both the spatial distance and the local environment, but environmental factors are the primary drivers of bacterial spatial patterns in the Qaidam Basin.

青藏高原的柴达木盆地是一个寒冷，高干旱的沙漠，给微生物群落带来了极大的挑战。关于表面和地下微生物群落之间的变化知之甚少，在这项研究中使用了高通量DNA测序技术来分析柴达木盆地三个区域不同深度收集的土壤样品的细菌群落。α多样性指数（Chao，Shannon和Simpson）表明，东部和高海拔地区的细菌丰度和多样性高于西部地区。一般来说，坚定 在西部地区占主导地位，而 变形细菌 和 酸菌在东部和高海拔地区占主导地位。细菌群落的结构在各个区域之间差异很大，与总有机碳（TOC）和总氮（TN）含量密切相关。地表和地下土壤样品之间细菌群落的差异小于整个地区的差异。对环境因素和细菌属的网络分析表明，所有地区均存在显着的正相关。总体而言，我们的研究提供了证据，即TOC和TN是整个柴达木盆地表层和地下细菌群落的最佳预测因子。这项研究得出的结论是，细菌群落结构受空间距离和当地环境的影响，