Table 1.
Soil chemical properties at different soil depths and study sites.
Fig 1.
Soil total/DTPA-extractable Pb (a) and Zn (b) concentrations at different soil depths and study sites.
The bar charts represent total Pb or Zn concentration, while the line graphs show DTPA-extractable Pb or Zn concentration. Each value is the mean ± SD (n = 6). Different letters indicate statistically significant differences (one-way ANOVA followed by SNK test, P < 0.05) at four soil depths (0–10, 10–20, 20–30, 30–40 cm).
Fig 2.
Mycorrhizal colonization (MC, a), AMF spore density (SP, b) and hyphal length density (HLD, c) at different soil depths and study sites.
Each value is the mean ± SD (n = 6). Different letters indicate statistically significant differences (one-way ANOVA followed by SNK test, P < 0.05) at four soil depths (0–10, 10–20, 20–30, 30–40 cm).
Fig 3.
Total glomalin-related soil protein (T-GRSP, a) and easily extractable glomalin-related soil protein (EE-GRSP, b) concentrations at different soil depths and study sites.
Each value is the mean ± SD (n = 6). Different letters indicate statistically significant differences (one-way ANOVA followed by SNK test, P < 0.05) at four soil depths (0–10, 10–20, 20–30, 30–40 cm).
Fig 4.
The percentage of water-stable aggregates (WSA, bar chart) and mean weight diameter (MWD, line graph) of rhizosphere soils at different soil depths and study sites.
Each value is the mean ± SD (n = 6). Different letters indicate statistically significant differences (one-way ANOVA followed by SNK test, P < 0.05) of MWD at five study sites (S1, S2, S3, S4 and S5).
Table 2.
Correlational analysis among GRSP concentration, soil properties AMF status at different soil depths and study sites.
Fig 5.
Redundancy analysis (RDA) of the correlations among soil aggregate distribution, stability and soil properties at 0–10 (a), 10–20 (b), 20–30 (c) and 30–40 (d) cm soil depths.
WSA1, WSA>2000 μm; WSA2, WSA2000-250 μm; WSA3, WSA250-53 μm; WSA4, WSA<53 μm; SOM, soil organic matter; SOC, soil organic carbon; TN, total nitrogen; TPb, total Pb; TZn, total Zn; DPb, DTPA-extractable Pb; DZn, DTPA-extractable Zn.