Climate refugia are expected to act as important reservoirs of biodiversity under future global warming. Great efforts have recently been made to identify refugia in the landscape using fine-scale meteorological data and models. However, predicting the viability of refugial plant populations in a future warmer and drier climate requires an in-depth understanding of the diverse processes related to their water use. In trees, stable isotope techniques are often used to quantify water use, taking advantage of the distinct isotopic composition of each water pool (i.e., rainfall, fog water, soil water or groundwater) and the partial preservation of this signal in the isotopic composition of tree-ring cellulose. HydroBeech will investigate the ecohydrological and ecophysiological mechanisms operating in an emblematic refugial population of beech (Fagus sylvatica L.) trees in the Ciron river gorge in SW France.
Teams from ECOFUN and BIOGECO preparing for early morning fieldwork in the Ciron valley.
We will combine high-resolution microclimate and stable isotope data in water pools and tree-ring cellulose with state-of-the-art, isotope-enabled ecophysiological and micrometeorological models in order to 1) unravel the effect of fine-scale variation in microclimate and edaphic conditions on tree water sources, 2) construct plot-level tree-ring isotope chronologies, 3) test for a genetic basis of the observed tree behaviour and 4) predict the long-term physiological responses of trees in this refugial population to climate change and forest and river management. The knowledge gained within HydroBeech will be highly relevant for predicting the performance of refugial forest tree populations under a warmer climate and for developing adequate climate mitigation strategies. It will also advance our mechanistic understanding of the tree-ring isotopic signal of deciduous species, which is crucial for both the field of dendro-ecology and climate research using tree-ring-based reconstructions.
Adria and Laura collecting fog and rainwater amongst the bees on the Ciron valley.
Bastien and Adria preparing the Beech drought isotope fractionation experiment
Camille, Adria, Laura and Kenza busy sampling in the glasshouse summer 2018
The HydroBeech team
- Dr Adria Barbeta
- Mr Bastien Frejaville
- Dr Jerome Ogee
- Dr Lisa Wingate
- Dr Teresa Gimeno
- Dr Camille Delvigne
- Dr Didier Bert
- Dr Arndt Hampfe
Project partners
The Labex Hydrobeech team also benefits from working closely and continuously with researchers and engineers working in the Ciron gorges:
- Natura 2000
- Syndicat Mixte d’Aménagement du Bassin Versant du Ciron (SMABVC)
Publications and Communications
Peer-reviewed articles
Barbeta, A., Burlett, R., Martin-Gomez, P., Frejaville, B., Devert, N., Wingate, L., Domec, J-C & Ogée, J. (2020) Evidence for distinct isotopic composition of sap and tissue water in tree stems: consequences for plant water source identification. bioRXiv 
Barbeta A., Gimeno T.E., Clavé L., Frejaville B., Jones S., Delvigne C., Wingate L. & Ogée J. (2020) Plant-source water isotopic mismatches are caused by heterogeneities within the soil pore and stem tissues. New Phytologist, 227, 766–779. 
Barbeta A., Jones S.P., Clavé L., Wingate L., Gimeno T.E., Fréjaville B., Wohl S., Ogée J. (2019) Unexplained hydrogen isotope offsets complicate the identification and quantification of tree water sources in a riparian forest. Hydrol. Earth Syst. Sci., 23, 2129-2146, doi: 10.5194/hess-23-2129-2019. 
Communications at international conferences
- Cernusak, L. et al., The dominant environmental driver of leaf water stable isotope enrichment differs for 2H compared to 18O American Geophysical Union Fall Meeting, San Francisco, 8th-13th December 2019 (INVITED)
- Martin-Gomez, P., Barbeta, A., Burlett, R., Ogée, J., Frejaville, B., Devert, N., Wingate, L. Is isotopic heterogeneity in tree water pools linked to phenology? American Geophysical Union Fall Meeting, San Francisco, 8th-13th December 2019 (INVITED)
- Barbeta, A., Burlett, R., Bakouri, K., Fréjaville, B., Jones, S., Wingate, L., Gimeno, T.E., Clavé, L., Delvigne, C., Wohl, S., Devert, N., Ogée, J., Isotopic heterogeneity in woody stems revealed by a new water extraction technique. Geophysical Research Abstracts, Vol. 21, EGU2019-14954, Vienna, Austria, 7-12th April 2019
- Barbeta, A., Gimeno, T., Clavé, L., Jones, S., Wingate, L., Frejaville, B, Ogée, J. Fractionation of δ2H during root water uptake is linked to plant transpiration in saplings of a temperate tree species American Geophysical Union (AGU) Fall Meeting, Washington, USA, 10th-14th December 2018
- Barbeta, A., Jones, S., Clavé, L., Fréjaville, B., Wingate, L. & Ogée, J. Ecohydrological study of a refugial Fagus sylvatica population using stable isotopes Geophysical Research Abstracts, Vol. 20, EGU2018-18983, Vienna, France, 9-13th April 2018