Figures and Tables Legends
FIGURE 1 Soil salinity (a) and pH (b) in the saline-alkali soil. Different lowercase letters represent significant differences (p ≤0.05). Means ± standard error (n = 3). CK, bare soil; BS, bulk soil of Melia azedarach L.; RS, rhizosphere soil of Melia azedarach L.
FIGURE 2 Concentrations of extractable soil elements, including Na (a), Mg (b), K (c), Ca (d) and Cl- (e) in the saline-alkali soil. Different lowercase letters represent significant differences (P ≤0.05). Means ± standard error (n = 3). CK, bare soil; BS, bulk soil ofMelia azedarach L. ; RS, rhizosphere soil of Melia azedarach L.
FIGURE 3 Soil enzyme activities, including alkaline phosphatase (a), urease (b) and catalase (c) in the saline-alkali soil. Different lowercase letters represent significant differences (P ≤0.05). Means ± standard error (n = 3). CK, bare soil; BS, bulk soil of Melia azedarach L. ; RS, rhizosphere soil of Melia azedarach L.
FIGURE 4 Venn diagram of the OTUs of bacteria (a) and fungi (b) in different soil samples. CK, bare soil; BS, bulk soil of Melia azedarach L. ; RS, rhizosphere soil of Melia azedarach L.
FIGURE 5 PCA analysis of bacteria (a) and fungi (b) based on OTUs. CK, bare soil; BS, bulk soil of Melia azedarach L. ; RS, rhizosphere soil of Melia azedarach L.
FIGURE 6 Comparison of relative abundance of bacterial (a) and fungal phyla (b). CK, bare soil; BS, bulk soil of Melia azedarach L. ; RS, rhizosphere soil of Melia azedarach L.
FIGURE 7 The LDA scores distribution histograms (b, d) showing taxa with significantly different abundance. The differences are mapped to cladograms (taxonomic trees) (a, c), with bacteria in the top part and fungi in the bottom part. Note: CK, bare soil; BS, bulk soil ofMelia azedarach L. ; RS, rhizosphere soil of Melia azedarach L. In the cladograms, the taxa associated with small circles and the shading in the colour of a specific soil played an important part in the microbial community in that soil (significantly different from other soils). The diameter of the small circle represents relative abundance of the taxa. The taxa without a significant difference are coloured yellow.
FIGURE 8 Correlations among soil physico-chemical and enzymatic properties. The pairwise comparisons are shown, with a color gradient denoting Spearman correlation coefficients. The non-significant correlations (P > 0.05) are not shown.
FIGURE 9 Redundancy analysis of soil physico-chemical properties with bacterial (a) and fungal taxa (b). The arrows represent environmental factors, and the arrow length indicates a degree of correlation between environmental factors and microbial communities. CK, bare soil; BS, bulk soil of Melia azedarach L. ; RS, rhizosphere soil of Melia azedarach L.
TABLE 1 Soil nitrogen, phosphorus, potassium and organic matter
TABLE 2 Alpha Diversity Indices
TABLE 1 Soil nitrogen, phosphorus, potassium and organic matter