Application of eco-physiological models to the climatic interpretation of δ13C and δ18O measured in Siberian larch tree-rings

• Published in: Dendrochronologia
• Main Authors: Churakova, Olga V., Shashkin, Aleksandr V., Siegwolf, Rolf T. W., Spahni, Renato, Launois, Thomas, Saurer, Matthias, Bryukhanova, Marina V., Benkova, Anna V., Kuptsova, Anna V., Peylin, Philippe, Vaganov, Eugene A., Masson-Delmotte, Valérie, Roden, John
• Other Authors: Universität Bern = University of Bern = Université de Berne (UNIBE), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Institut Paul Scherrer (IPS), Sukachev Institute of Forest, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Siberian Federal University (SibFU), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Southern Oregon University (SOU)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: Northeastern Yakutia; stable isotopes in tree-ring width; permafrost; climate; water source; thaw depth; [SDE.MCG]Environmental Sciences/Global Changes; Yakutia; Siberia
• Online Access: https://hal.inrae.fr/hal-02640095; https://doi.org/10.1016/j.dendro.2015.12.008

International audience Tree-ring width and stable isotopic composition are widely used for the reconstruction of environmental conditions. Eco-physiological models simulating δ13C and δ18O provide tools to constrain the interpretation of measured tree-ring variations and their relationships to environmental variables. Here, we apply biochemical models of photosynthesis and a model of stomatal conductance to simulate the intra-annual dynamics of δ13C values in photo assimilates and tree-rings. We use these models to investigate the physiological responses of larch trees growing on permafrost to variability in precipitation and permafrost depth associated with regional temperature and precipitation changes. Tree-ring width, δ13C and δ18O in wood and cellulose were measured in larch (Larix cajanderi Mayr.) samples from northeastern Yakutia (69°N, 148°E) for the period from 1945 to 2004 and used for comparisons with modeled δ13C and δ18O data. Mechanistic models that quantify physical and biochemical fractionation processes leading to oxygen isotope variation in organic matter are used to identify source water for trees growing on permafrost in Siberia. These models allowed us to investigate the influence of a variety of climatic factors on Siberian forest ecosystem water relations that impact isotope fractionation. Based on δ13C and δ18O in tree wood and cellulose measurements as well as outputs from different eco-physiological models, we assume that larch trees from northeastern Yakutia can have limited access to the additional thawed permafrost water during dry summer periods.