TreeWater - Disentangling the isotopic signal transfer from source water to tree rings

TreeWater aims to improve our understanding of whether and how information on water uptake dynamics can be retrieved from the oxygen and hydrogen (i.e. water) isotopes in tree rings. Specifically, we will (1) link high-resolution data of water isotopes of precipitation and soil solutions with those in tree rings over 12 years (2010-2022) on Swiss long-term forest monitoring sites; (2) determine the influence of wood anatomy and growth dynamics on water stable isotope ratios in tree rings across species, sites, and seasons; (3) analyze the effect of seasonal variations in concentration and isotopic composition of nonstructural carbohydrates on water isotopes in tree rings. With this setup, our project will validate and improve recent tree-ring isotope models that are intended to be used to estimate hydrological processes and the spatiotemporal origin of tree water sources. The project contributes to the EU CostAction WATSON #CA19120 (