2.4. Statistical analysis
Significant differences among treatments were analyzed by the two-factor variance of analysis (ANOVA) with Duncan test (p<0.05) to evaluate the effect of soil gravel content, plant species and their interaction on plant traits during vegetation restoration. Pearson’s correlation analysis was used to examine the relationships between plant traits and soil properties. Redundancy analysis (RDA) was conducted to analyze the relationships between plant trait indices, the content of C, N, and P and their stoichiometric characteristics and soil properties under different plant species treatments. All data analyses were performed using SPSS 20.0 and Canoco 4.5.