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• Bacteria and eukaryota diversity increased with increasing longitude and elevation. • Archaeal diversity decreased slightly with increasing elevation. • Some phyla diversity patterns are individually inconsistent with the overall trend. • Geographic distance contributed more than environmental factors to soil microbes. • More intra-domain than inter-domain links within the soil microbial network. Recent studies show that different microorganisms, especially bacteria and fungi, exhibit contrasting latitudinal, longitudinal, and altitudinal diversity patterns at a global scale, but little is known about biogeographic patterns in desert ecosystems. In this study, we chose a narrow geographic channel, namely the deserts of northern China's Hexi Corridor as the study area. Based on field survey and next-generation sequencing (Illumina MiSeq PE300 Platform), to map soil microbial geographic diversity patterns in this area and further determine the main driving factors responsible for shaping the soil microbial community. The results show that bacteria and eukaryotic diversity increased linearly with increasing longitude and altitude, but decreased with increasing latitude in the Hexi Corridor deserts, whereas archaeal diversity showed little change along these geographic gradients. Some individual phyla within the bacterial, archaeal, and eukaryota communities were not always consistent with collective trends, e.g., for the α-diversity of the ten most dominant bacterial phyla, only six phyla showed a statistically significant increase with altitude. The soil microbial community composition was jointly shaped by geographic distance and environmental variables (regional climatic factors and local edaphic variables). The effect of geographic distance on the soil microbial community composition was slightly stronger than that of the environmental variables. Intra-domain links were stronger than inter-domain links in the soil microbial network of the Hexi Corridor deserts, and these links were mostly positive. Although bacteria formed more connections than both archaea and eukaryotes, removing the archaea resulted in a lower natural connectivity, suggesting that the archaea were the core group for building this desert region's soil microbial co-occurrence network. Taken together, these findings deepen our understanding of regional-scale soil microbial diversity patterns in this desert ecosystem. [ABSTRACT FROM AUTHOR]

Mowing and burning, two common human disturbance methods, have different impacts on the soil fungal and bacterial communities of sandy land ecosystems in semiarid areas. Thus, the effects of long-term mowing and burning on plant and soil microbial communities in the semiarid Horqin Sandy Land are unclear. In this study, the effects of soil microbial community structure from mowing and burning on plant and soil microbial communities over six years were assessed by high-throughput sequencing. First, we found that mowing and burning significantly reduced vegetation coverage (V) (p < 0.05), and burning significantly increased plant Shannon–Wiener diversity (H), Pielou evenness (E), and Simpson dominance (λ) indices (p < 0.05). Second, the two human disturbances markedly affected fungal diversity and abundance more than bacterial diversity and abundance. In fungi, burning significantly reduced beta diversity (p < 0.05) and the relative abundance of Basidiomycota (p < 0.05) but markedly increased the relative abundance of Ascomycota and Mortierellomycota. Third, redundancy analysis (RDA) showed that vegetation coverage was a significant factor in bacterial species distribution (p < 0.05). For fungi, the significant factors were species richness (S) and vegetation coverage (p < 0.01). Taken together, these data suggest that long-term mowing and burning have more of an effect on soil fungal communities than bacteria in a semiarid sandy land, improving our understanding of how terrestrial ecosystems respond to human disturbances and providing guidance for the management and restoration of sandy desertification. • Mowing significantly reduced vegetation coverage. • Burning could change the plant community diversity. • Mowing and burning markedly affected fungal diversity and abundance more than bacteria. • Vegetation coverage was the significant factor in bacteria species distribution. • Fungal community was more easily influenced by plant community diversity. [ABSTRACT FROM AUTHOR]