Fig. 6

Co-occurring ecological networks of fungal OTUs (order level) according to the random matrix theory. Each node represents an OTU. The connectivity between two OTUs is indicated by an edge. Blue and red edges represent positive and negative correlations, respectively. The colors of the nodes denote different phyla. The greedy modularity optimization method was used to form each of the three ecological network modules in the gold anomaly (a–c) and the reference (d–f) from fungal communities. The size of each circle indicates the degree of Stress Centrality c_S(x) to each OTU in the gold anomaly and the reference area. The Stress Centrality index is used to describe the approximate amount of stress a node x has to sustain in the network by counting the number of short paths that contain node x. Thus, a node is more central when more short paths run through it. The node at the six o’clock position of each module has the most connections to other nodes. The degree of connection decreases counterclockwise. Detailed taxonomic annotations and the network nodes’ centrality indexes for each OTU are shown in Supplementary Data 2–4