Fig. 2

Structural equation model (SEM) illustrating the links between bacterial and fungal abundances and the relative abundance of microbe-consuming protists on crop yield (a). Heatmap illustrating the relative abundance of microbe-consuming protistan OTUs associated with crop yield in all treatments (b). In panel (a), *indicates P < 0.05; **indicates P < 0.01. Solid and dashed lines represent significant and non-significant relationships, respectively, with blue arrows depicting positive relationships and red arrows negative relationships. Numbers associated with lines indicate path coefficients, and line width is proportional to the effect size. The low chis-square (χ2 = 0.458), high goodness-of-fit index (GFI = 0.797), low Akaike information criteria (AIC = 18.458), and low root mean-square errors of approximation (RMSEA = 0.000) indicate that our data matches our hypothetical model. In panel (b), the colour key relates the heatmap colours to the standard score (z-score). Plus signs indicate positive, and minus signs negative correlations between OTUs and crop yield. Different letters indicate significant differences as defined by Tukey's HSD test (P < 0.05). Circles are proportional to the average relative abundance of each group across all samples