Figure 8.

Contribution biplots generated by log-ratio analyses for taxonomic levels from OTU to phylum. The total variance in the complete datasets as accounted by the two principal row coordinates (dim1 and dim2) is provided in the appended parentheses. The contribution vectors (bacterial taxa) were scaled to fit into the scatter plots of the treatments. For the treatments (TiO₂ and ZnO MNPs and controls (Ctrl)), the exposure time is denoted by “##d” with “L”, “M”, “H” corresponding to doses of 0.5, 1.0, 2.0 mg/g (soil) and 0.05, 0.1, and 0.5 mg/g (soil) for TiO₂ and ZnO MNPs, respectively. The contribution vectors are omitted for the plot of OTU level to avoid cluttering the plot.