Figure 3. Relationships between the difference in predawn and midday leaf water potential (ΔΨ) and the predawn leaf water potential (Ψpd) for P. nigra , P. sylvestris , Q. faginea, and Q. ilex in monospecific (red), monofunctional (orange), multifunctional (light blue) and four-species mixture plots (dark blue). Lines represent linear regressions with significant relationships across all species diversity levels.