Fig. 3
From: Below-ground hydraulic constraints during drought-induced decline in Scots pine
Daily averages of predawn (ψPD; dark grey) and midday (ψMD; light grey) leaf water potential measurements in defoliated and non-defoliated Scots pine trees in (a) spring and (b) summer of 2012. Different uppercase letters indicate significant differences (P < 0.05) between predawn measurements, different lowercase letters indicate significant differences between midday measurements and different Greek letters indicate significant differences in the water potential difference between predawn and midday (Δψ) across defoliation classes and seasons. Error bars indicate ± 1 SE