Fig. 5
Boxplots of average ER (a), tree diameter (b), tree age (c), and wood MC (d, e, f) for the 3 types of tomographic profiles observed (type 1: n = 6; type 2: n = 26; type 3: n = 26). Mean electrical resistivity (ERmean; Ωm) was calculated from averaged values of each of the entire cross-section (a). Tree diameter was measured at breast height (b). Tree age (c), mean (d), heartwood (e), and sapwood (f) moisture content were measured using the wood core. Boxplots indicate the median (thick central line), interquartile range (box), minimum and maximum (whiskers), and outliers (circles). Different letters indicate significant differences