AustriaCountry of destination:
Winter freezing tolerance is one of the key factors limiting distribution of plants in many ecosystems. Freeze-thaw cycles are inducing embolism in wood vessels, which could lead to death of the tree. Based on the new Acoustic Emissions analysis (AE) method, (i) characterisation of AE signals related to species’ anatomy, (ii) visualisation of ice formation and water flow in freezing stems, and (iii) frost damage in living cells and the xylem of trees growing at the alpine timberline will be analysed. The new method will help to improve future forest management and will enable new insights into mechanisms of frost resistance.
My primary research interest is the understanding of plant ecophysiological responses to environmental changes.I am measuring physiological parameters (hydraulic safety, hydraulic efficiency, freezing tolerance) of trees under drought and frost stress, particularly at the timberline. During my first training experience (first year of my master’s degree), I learned ecological concepts as I worked with growth dynamics and nitrogen economy in thermic and snowy situations of alpine Cariceae (Laboratory of Alpine Ecology, Grenoble, France). I started ecophysiological research during my second year master training experience, studying winter drought stress in trees growing at the alpine timberline (Institute of Botany, University of Innsbruck, Austria). My PhD was focused on hydraulic efficiency and safety of conifer needles in the context of tree hydraulic architecture (Institute of Botany, University of Innsbruck, Austria). Working as AgreenSkills fellow at INRA, UMR PIAF, Clermont-Ferrand in collaboration with the Institute of Botany of Innsbruck, I have extended my ecophysiological knowledge on freezing resistance of trees, using ultrasonic acoustic emissions analysis emitted by branches submitted to freeze-thaw cycles.
Charra-Vaskou K., Badel E., Charrier G., Ponomarenko A., Bonhomme M., Foucat L., Mayr S., Améglio T., 2016. Cavitation and water fluxes driven by ice water potential in Juglans regia during freeze-thaw cycles. Journal of Experimental Botany, 67: 739-750.
Charrier G., Pramsohler M., Charra-Vaskou K., Saudreau M., Améglio T., Neuner G., Mayr S., 2015. Ultrasonic emissions during ice nucleation and propagation in plant xylem. New Phytol. 207(3):570-578.
Charrier G., Charra-Vaskou K., Kasunga J., Cochard H., Mayr S., Ameglio T., 2014. Freeze-thaw stress: detection of embolism sensitivity by ultrasonic emissions in the wood of angiosperms. Plant Physiology 164: 992-998.
Charrier G., Charra-Vaskou K., Legros B., Ameglio T., Mayr S., 2014. Changes in ultrasound velocity and attenuation indicate freezing of xylem sap. Agricultural and Forest Meteorology 185: 20-25.
Mayr S. Schmid P., Laur J., Rosner S., Charra-Vaskou K., Dämon B., Hacke U., 2014. Uptake of water via branches helps timberline conifers refill embolized xylem in late winter. Plant Physiology 164: 1731-1740.
2011: France Prize of the Interdisciplinary Pole of French Studies for my PhD “Analysis of important aspects in hydraulic efficicency and safety of conifer needles”
2012 (2nd round): Agreenskills Fellow