Figure 8

Correlation between SMY and soil properties. The figure is divided into two diagonals. The lower triangle on the left is the correlation of ptwo indicators, *indicates a significant difference at the P < 0.05 level, **indicates a significant difference at the P < 0.01 level, *** indicates a significant difference at the P < 0.001 level, red represents a positive correlation, blue represents a negative correlation, the darker the colour, the greater the correlation. The figures in the upper right triangle are pairwise indicator correlation coefficients.