Stable isotopes are powerful tools for tracing water fluxes and associated nutrients in the soil-plant-atmosphere continuum. Given the complex interactions between subsurface water fluxes, plant water uptake and atmospheric drivers, new field- and laboratory-based methods should enable observations of ecohydrological processes at a high temporal and spatial resolution and with high precision and accuracy. At the same time, ecohydrological models shed new light on water and nutrient fluxes in the soil-plant-atmosphere continuum. We welcome experimental and modelling studies that present methodological developments and applications of isotope tracers to improve our process knowledge of water and nutrient fluxes between the subsurface, plants and the atmosphere, across different scales (from plant and forest stand up to the catchment scale). In our session, we aim to discuss i) innovative process-based interpretations from stable isotope data, ii) novel methods of model applications and data analysis, as well as iii) current methodological developments. We aim to foster interdisciplinary exchange between the various fields assessing ecohydrological processes using natural tracers, including research in groundwater and vadose zone hydrology, plant physiology, and ecology.