A simplified framework for fast and reliable measurement of leaf turgor loss point

Drought tolerance shapes the distribution of plant species, and it is mainly determined by the osmotic potential at full turgor (π₀) and the water potential at turgor loss point (Ψ_tlp). We provide a simplified framework for π₀ and Ψ_tlp measurements based on osmometer determination of π₀ (π_{0_osm}). Specifically, we ran regression models to i) improve the predictive power of the estimation of π₀ from π_{0_osm} and morpho-anatomical traits; ii) obtain the most accurate model to predict Ψ_tlp on the basis of the global relationship between π₀ and Ψ_tlp. The inclusion of the leaf dry matter content (LDMC), an easy-to-measure trait, in the regression model improved the predictive power of the estimation of π₀ from π_{0_osm}. When π_{0_osm} was used as a simple predictor of Ψ_tlp, discrepancies arose in comparison with global relationship between π₀ and Ψ_tlp. Ψ_tlp values calculated as a function of the π₀ derived from π_{0_osm} and LDMC (π_{0_fit}) were consistent with the global relationship between π₀ and Ψ_tlp. The simplified framework provided here could encourage the inclusion of mechanistically sound drought tolerance traits in ecological studies.