Fig. 4
From: Below-ground hydraulic constraints during drought-induced decline in Scots pine
(a–c) Seasonal course of daily averages of below-crown hydraulic resistance (rbc) in defoliated (red) and non-defoliated (blue) Scots pine trees over the three seasons studied in 2012. Different letters indicate significant differences (P < 0.05) between seasons within a given defoliation class. (d, e) Percent contribution of below-crown resistance to whole-tree hydraulic resistance (%rbc). Different uppercase letters indicate significant differences (P < 0.05) between seasons, and different lowercase letters indicate significant differences between defoliation classes within a given season. Error bars indicate ± 1 SE in all panels. Note that we did not measure leaf water potentials in winter, so we could not estimate %rbc for this season