Fig. 2

The construction of integrated co-occurrence networks of soil organisms (including bacteria, fungi, protists, and nematodes) and proportions of potential multi-trophic interactions types in low and high available resource environments. a Visualization of integrated co-occurrence networks across low (left) and high (right) resource availability environments based on Spearman correlation matrix (|r|> 0.6, P < 0.05). Each node represents OTUs. These nodes were clustered according to the category of kingdoms and marked with purple (nematode), green (protist), yellow (fungi), and white (bacteria) colors. Each link between the same and different kingdoms represents a significant pairwise association between them. The color of links was used to distinguish trophic levels between nodes. Blue links represent within trophic associations (potential within trophic interactions), while red links represent cross-trophic association (potential cross-trophic interactions). The shape of links was used to distinguish the impact of associations. The solid and dashed lines represent positive and negative associations between nodes, respectively. The thickness of links represents the proportion of a certain type of association in total associations. b, c Average proportion of within trophic (WTA) and cross-trophic associations (CTA) in low and high available resource. Asterisks denote significant differences between metrics for low and high resource availability soils (n = 30) (Wilcoxon rank-sum test, asterisk, P < 0.0001; ns, not significant)