No evidence of isotopic fractionation in olive trees (<i>Olea europaea</i>): a stable isotope tracing experiment

Plant transpiration is the dominant water flux in global terrestrial balance and a key process hydrological sciences. Stable isotopes have contributed greatly to this understanding but one difficult assumption for plant source quantification using hydrogen oxygen that no isotopic fractionation occurs during uptake transport within plant. Here we present simple glasshouse experiment with two potted olive trees test fractionation. We irrigated labelled cryogenically extracted from twigs, cores roots. found significant differences composition of wood twigs distinct parts as they reflected signature water. However, were obtained between deep soil Our results suggest trees, under specific experimental conditions, validating traditional isotope-tracing approach.