Fig. 4: Co-occurrence networks for bacterial and fungal communities based on amplification sequence variations (ASVs).

a, b The bacterial and fungal networks in 11 layers of S0 ~ S5. c, d The networks of bacteria in S and L in L2-S5, respectively. e, f The networks of fungi in S and L in L2-S5, respectively. A connection in bacteria stands for a correlation coefficient |r | > 0.7 and P < 0.01, and |r | > 0.5 and P < 0.05 in fungi. The keystone taxa (module hubs and connectors) and their connected edges in the networks are in bold. The size of each node is proportional to the number of connections (degree), and the thickness of each connection between two nodes (edge) is proportional to the value of Spearman’s correlation coefficients. The blue edges indicate positive interactions between two nodes, while red edges indicate negative interactions. The legend shows main modularity class in order of their relative amount. g Topological properties of microbial co-occurring networks in Modularity, Average clustering coefficient, Average path length and Average degree for bacterial and fungal of whole LPS layers (a and b); bacterial of deep S and L (c and d, respectively); fungi in deep S and L (e and f, respectively). h The variation of both phylogenetic diversity and taxonomic diversity of microbial β-nearest taxon index (betaNTI) and RCbray (Bray–Curtis-based Raup–Crick) values in Top and deep layers, respectively. i Give the percent of turnover in community composition governed primarily by variable selection, homogenizing dispersal, dispersal limitation and ecological drift.