Soil Microbial Community Co-occurrence Network Structure and Its Drivers in Arid Mountainous Areas

In August 2021, eight typical vegetation zones—Desert Steppe (DS), Prunus mongolica (PM), Ulmus glaucescens (UG), Pinus tabuliformis (PT), aspen×juniper mixed forest (AJMF), spruce×juniper mixed forest (SJMF), Picea crassifolia (PC), and Alpine Meadow (AM) —were selected at altitudes between 1800-3000 m on the western slopes of the Helan Mountains in Ningxia. Six standard plots were established for desert grassland and alpine meadow zones, while 12 standard plots were set up for each of the other vegetation zones as replicates, following the contour lines. The plot sizes were 20 m × 20 m for forest plots, 5 m × 5 m for shrub plots, and 1 m × 1 m for grass plots.