3.3 Relationships between P50 root - branch and hydraulic traits of xylem
There was a significantly positive correlation betweenP 50 branch and P 50 root - branch (r 2 = 0.31, P < 0.001; Figure 3a). However, the correlation between P 50 root and P 50 root - branch was not significant (r 2 = 0.02, P < 0.05; Figure 3b). Both K S branch and K S root had significant correlations with P 50 root - branch (r 2 = 0.14 and 0.09, respectively,P < 0.001; Figure 3c, 3d). In general, xylem specific hydraulic conductivity (K S) decreased with an increase of hydraulic vulnerability segmentation between roots and branches, but P 50 increased withP 50 root - branch (Figure 3).