18O isotopic labelling and soil water content fluctuations validate the hydraulic lift phenomena for C3grass species in drought conditions

•The isotopic labelling and soil water content monitoring methodologies adopted in the study enabled the validation and assessment of the hydraulic lift in grass species.•The species’ root morphology and allocation at depth may explain the hydraulic lift phenomena occurrence since a more even root system distribution was found in B. valdivianus, which had a dry matter ratio of approximately 4:1 (0–20cm:20–40 cm). In contrast, L. perenneand D. glomeratahad approximately 6:1 and 5:1, respectively.•This paper validates the occurrence and provides initial insights into the hydraulic lift phenomena in temperature grass species.•According to the C-S-R model, the multivariate analysis highlighted the three grass species’ morpho-physiological strategies to cope with soil water stress.•The study indicates that B. valdivianusand D. glomeratapresented attributes of stress-tolerators and, under lower levels of water restriction, can also present attributes of competitors, while L. perenneonly presented attributes of competitors, highlighted by its lack of adaptative responsiveness under water stress.