FIGURE 3.

Principal Coordinates Analysis (PCO) biplots on the long-term effect of tillage and nitrogen fertilization on community diversity of prokaryotic classes at 0–15 cm soil depth (A), prokaryotic phyla at 0–15 cm (B), fungal families at 0–15 cm (C), fungal families at 15–30 cm (D), fungal phyla at 0–15 cm (E), fungal families at 15–30 cm (F). The output of the subfigures is based on the significant effect of treatments following the permutational analysis of variance. In each PCO biplot, we displayed only the phyla, classes and families with a strong correlation (r ≥ 0.70) with the ordination scores on each PCO axis. Data standardized to the median were square-root transformed and Bray-Curtis coefficients of similarity were calculated between samples.