Natural abundance and enriched stable isotopes are exceptional tracers, contributing to deeper comprehension of the transport and transformation of water, carbon, and other elements. Their use has led to novel insights into the Critical Zone and soil-plant-atmosphere continuum. Furthermore, new developments have facilitated tracing of system exchanges and feedback processes on many levels, from micro- to regional-scales, including variability across timescales and connections between local processes and larger-scale behavior. With such advancements, new opportunities and perspectives have arisen, fostering interdisciplinary approaches to Critical Zone processes. This session aims to bridge bio-hydro-geo-eco communities by showcasing studies that use stable isotopes to enhance our understanding of the Critical Zone and/or to advance relevant stable-isotope methods, interpretation frameworks, and application techniques. We welcome studies that transcend disciplinary boundaries and adopt innovative approaches to improve process understanding. Additionally, this session encourages opinions, perspectives, and syntheses that guide the Critical Zone stable isotope community.

• B - Biogeosciences