Fig. 1: Composition, assemblage, and networks of the Tibetan Plateau aquatic microbial communities.

a Geographic distribution of metagenomic samples from six water ecosystems (Saline lakes, Freshwater lakes, Rivers, Hot springs, Wetlands, and Glaciers) in two large-scale regions (Tibet and Qilian). b Microbial community compositions (n = 498 independent samples) plotted on a PCoA plot based on Bray–Curtis distance of the genera profiles produced by the MetaPhlAn (version 4.0.1)³⁷. The statistical significance of the dispersions between groups is calculated by PERMANOVA (R² and P). The shaded ellipses represent the 85% confidence interval, and the dotted ellipse borders represent the 90% confidence interval. Boxplots show the sample distributions against the PCo 1 and PCo 2 axes. Boxes represent the interquartile range between the first and third quartiles and the line inside represents the median. Whiskers denote the lowest and highest values within the 1.5×interquartile range from the first and third quartiles, respectively. c Fit of the NCMs of microbial community assemblage across five water ecosystems in Tibet. The solid red lines indicate the best fit to the NCM, and the dashed red lines represent 95% confidence intervals around the model prediction. Genera that occur more or less frequently than those predicted by the NCM are shown in different colors. R² indicates the fit of the model. d The MENs of five water ecosystems in Tibet were constructed based on Spearman correlations of genera relative abundances produced by MetaPhlAn (version 4.0.1)³⁷. Modules with ≥2 nodes are shown in different colors, and smaller modules are shown in gray. Details of network topological attributes are listed in Supplementary Data 2.2. The NCMs and MENs in Qilian are shown in Supplementary Fig. 2c and d, respectively. PCOA, principal coordinates analysis; PERMANOVA, Permutational multivariate analysis of variance; NCM neutral community model, MEN molecular ecological network.