highly significantp < 0.001
Coefficients of determination were relatively high for each individual tree (BB: 0.66 ± 0.19, RO: 0.62 ± 0.12, HE: 0.69 ± 0.11, ME: 0.82 ± 0.17, Supplementary Tables S1–S4 ) and for site mean sap flow (BB: 0.80, RO: 0.68, HE: 0.74, ME: 0.90), all highly significant (p < 0.001).