Fig. 2
From: Below-ground hydraulic constraints during drought-induced decline in Scots pine
Seasonal course of (a–c) daily vapour pressure deficit (VPD), (d–f) soil water content (SWC), (g–i) daily-averaged sap flow per unit leaf area (JL) and (j–l) stem pressure difference (ΔPbc) for the three seasons studied in 2012. JL and ΔPbc are given for defoliated (red) and non-defoliated (blue) Scots pine trees. Error bars indicate + 1 SE. Arrows in the lower panel indicate sampling dates of leaf water potentials