3.4 Correlation analysis among characteristic indexes
The correlation analysis of eight height indicators, LWC, AGB, BGB, and four photosynthetic characteristic indexes showed that there was a significant positive correlation between height and AGB, with a correlation coefficient of 0.383 (P <0.01), and a negative but not significant correlation with BGB. LWC was negatively correlated with AGB and Ci, with correlation coefficients of -0.472 and -0.280, respectively (P <0.01), and had a significantly positive correlation with Pn (P <0.05). Pn had a significantly positive correlation with Tr and Gs, with correlation coefficients of 0.384 and 0.373, respectively (P <0.01). Tr had a significantly positive correlation with Gs and Ci (P <0.01), with correlation coefficients of 0.426 and 0.349, respectively. Finally, Gs and Ci had a significantly positive correlation, with a correlation coefficient of 0.380 (P <0.01) (Table 3).