Does the turgor loss point characterize drought response in dryland plants?

The water potential at turgor loss point ( Ψ tlp ) has been suggested as a key functional trait for determining plant drought tolerance, because of its close relationship with stomatal closure. Ψ tlp may indicate drought tolerance as plants, which maintain gas exchange at lower midday water potentials as soil water availability declines also have lower Ψ tlp . We evaluated 17 species from seasonally dry habitats, representing a range of life‐forms, under well‐watered and drought conditions, to determine how Ψ tlp relates to stomatal sensitivity (pre‐dawn water potential at stomatal closure: Ψg s 0 ) and drought strategy (degree of isohydry or anisohydry; Δ Ψ MD between well‐watered conditions and stomatal closure). Although Ψg s 0 was related to Ψ tlp , Ψg s 0 was better related to drought strategy (Δ Ψ MD ). Drought avoiders (isohydric) closed stomata at water potentials higher than their Ψ tlp ; whereas, drought tolerant (anisohydric) species maintained stomatal conductance at lower water potentials than their Ψ tlp and were more dehydration tolerant. There was no significant relationship between Ψ tlp and Δ Ψ MD . While Ψ tlp has been related to biome water availability, we found that Ψ tlp did not relate strongly to stomatal closure or drought strategy, for either drought avoiders or tolerators. We therefore suggest caution in using Ψ tlp to predict vulnerability to drought.