A plot of principal component scores, cluster dendrogram, and shape of typical load–deflection curves for juvenile and mature wood. Note: PC1 and PC2 are the first and second principal components, respectively. The plotted codes in the top figure are Family ID. The vertical axis in the middle figure shows the distance between families based on the squared Euclidean distance using the Ward hierarchical clustering algorithm. Family groups I, II, III, and IV show types of load–deflection curve described as LDC-I, LDC-II, LDC-III, and LDC-IV in the bottom figure, respectively. Load–deflection curves of LDC-I, LDC-II, LDC-III, and LDC-IV in juvenile wood were obtained from H2, S2, M5, and S in Family ID, and similarly in mature wood, from H2, S2, S, and T2 in Family ID, respectively.