Fig. 3

Network analysis revealing microbial co-occurrence patterns and ecological characteristics of different subsurface habitats based on the top ASVs (relative abundance > 0.01%). a The co-occurrence network and module division of the five main modules (M1–M5) when considering all samples. Distinct modules represent differences in niches. Taxonomic compositions of modules were estimated based on the composition of ASV abundance-weighted nodes within the module. b The distribution of distinct groups of environmental samples in each module reveals which niches (modules) the samples from various habitats primarily represented. c Topological properties of PW (5, 6, 7), PW (8, 9, 10), and sandstone core subnetworks. d Co-occurrence patterns of the subnetworks in specific habitats and their node compositions. e Correlation network showing the significant link between microbial species and electron acceptors (sulfate and nitrate). A connection represents a strong and significant correlation with Spearman’s coefficient of |r| > 0.7 and p-value < 0.01. The genera of the ASVs are listed in nodes, and the colors of nodes signify the phyla with which the ASVs are affiliated. Red and green edges denote positive and negative correlations, respectively. Node size and linewidth correspond to the relative abundance of ASVs and the absolute value of correlation coefficients, respectively