Statistical analysis
Repeated measures analysis of variance (ANOVAr) with Tukey’s honest significant different (Tukey ‘s HSD) test was used to estimate the significant variation among treatment combinations of the leaf physiological, morphological, and chemical traits among the tree age stages. Data was tested for normality and homogeneity of variance, and, if necessary, log10 transformation of the data was done before analysis. The relationship between physiological, leaf morphological, and chemical traits was determined using multiple linear regression with regression equations. All analyzed correlations were considered significantly different when p< 0.05. All the statistical analysis was performed using R 3.4.4 (R Development Core Team).