Fig. 1
From: Changes of secondary metabolites in Pinus sylvestris L. needles under increasing soil water deficit
Relationships of predawn shoot water potential (Ψpd) with stomatal conductance (g s) (a) and with net CO2 uptake (A) (b) measured in five Scots pines along a water deficit period. I–III: physiological phases considered. Ψ pd,1 : limit between phases I and II defined as the change in the slope of the relationship between Ψpd and g s. Ψ pd,2 : limit between phases II and III defined as the point where A is zero