Fig. 3

Mean annual basal area increment of black spruce trees since their establishment after the last fire event. The decrease in sample depth (i.e., number of trees included in the chronologies) at CAS100 since 2000 is explained by some trees for which the latest rings were partly missing. See Fig. S2.3 for BAI distribution. Boxplots show the median, quartile range, extreme values (dotted lines), and outliers (dots) of the distribution. Different letters above the boxes indicate significant differences between the sites based on Tukey’s HSD test