Figure 7. Relationships between the predawn leaf water potential (Ψpd), the difference in predawn and midday leaf water potential (ΔΨ), the light-saturated stomatal conductance (gs), and the belowground community-level water source partitioning for P. nigra (brown), P. sylvestris (beige), Q. faginea (light green) and Q. ilex(dark green) in the four-species mixtures (mean ± SE per plot and date). Lines represent significant linear regressions for each species.