Fig. 3

Associations between DOM composition, bacterial community, and the environmental drivers. a The influences of geographical factors, edaphic factors, and DOM composition features on the bacterial community structure estimated via canonical correspondence analyses (CCA). b The influences of geographical factors, edaphic factors, and bacteria community features on the DOM composition estimated via CCA. The percentages represent the variance explained. c, d Multivariate analysis of microbial or molecular data and drivers using non-metric multidimensional scaling (NMDS). Ordinations are based on Bray-Curtis (c, stress = 0.1656; d, stress = 0.1479). Geographical factors, edaphic factors, and DOM composition (c) or bacteria (d) community were fit to the ordination using envfit function, respectively. Only factors with significance level ≤ 0.001 were shown. e Spearman’s rank correlations between DOM diversity features (y axis) and edaphic, geographical, and bacterial factors (x axis), with color coded in blue, red, and yellow, respectively. All factors imported and their influences are listed in Additional file 3: Table S2 and Additional file 4: Table S3. MAP, mean annual precipitation; MAT, mean annual temperature; MMP, mean monthly precipitation; MMT, mean annual temperature; RST, real-time soil temperature; RAT, real-time air temperature