EGU General Assembly 2020
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Tracing plant water fluxes in ecosystems by stable isotopes along the soil-plant and plant-atmosphere interfaces

Christiane Werner
Christiane Werner
  • Freiburg, Faculty of Enviroment and natural resources, Ecosystem Physiology, Freiburg, Germany (

Terrestrial vegetation is a main driver of ecosystem water fluxes, as plants mediate the water fluxes within the soil-vegetation-atmosphere continuum. Stable isotopologues of water are efficient tracer to follow the water transfer in soils, uptake by plants, transport in stems and release into the atmosphere through stomata. The development of in-situ methods coupled to isotope spectroscopy does now enable real-time in-situ water vapour isotopologue measurements revealing high spatial and temporal dynamics, such as adaptations in root water uptake depths (within hours to days) or the impact of transpirational fluxes on atmospheric moisture.

Examples will be given how isotopes can be used to inform the complex interplay between plant ecophysiological adaptations and hydrological processes. For example, root water uptake is not solely driven by soil water availability but has to be understood in the context of species-specific regulation of active zones in their rooting system determining the conductivity between soil and roots regulating uptake depths. The latter has also to be evaluated in context of the nutrient demand and the spatial nutrient availability. Similarly, plant water transport and losses are a fined tuned interplay between species-specific structural and functional adaptations and atmospheric processes.

Finally, first data of a large-scale ecosystem labelling experiment at the Biosphere 2 tropical rainforest of the B2 Wald, Atmosphere, and Live Dynamics (B2WALD) will be presented.

How to cite: Werner, C.: Tracing plant water fluxes in ecosystems by stable isotopes along the soil-plant and plant-atmosphere interfaces, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11289,, 2020

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Display material version 1 – uploaded on 01 May 2020
  • CC1: Comment on EGU2020-11289, Anke Hildebrandt, 06 May 2020

    Exciting research!

    How deep is the soil in Biosphere 2 and how deep was the label?

    On slide 16: Does the plot show different species? 

    • AC1: Reply to CC1, Christiane Werner, 06 May 2020

      The soils in the Biosphere are between 3-5m deep. We applied the labell at the bottom (sealed floor) through the drainage pipes. Yes the Figure shows the different velocities of uptake in different trees. Some took realy long and kept transpiring the labelled water even weeks after we started the (unlabelled) rain again


  • CC2: question about a name of a plot axis, Gökben Demir, 06 May 2020

    what is the x-axis of the plots which is under the title of "Partitioning understory evapotranspiration"?

    • AC2: Reply to CC2, Christiane Werner, 06 May 2020

      X-axes are the date of the measurements, sorry for that

  • AC3: Comment on EGU2020-11289, Christiane Werner, 06 May 2020
    Jesse Radolinski University of Innsbruck (16:19) Christiane, assuming same species and setup, do you think labeling from above ground would decrease the transit time to traspiration?
    After such a long drought, some trees refilled the stem (Joost has nice data on this) before they start transpiring, which was the reason for the delay time. That migh be the same for aboveground labelling. Shallow-rooted trees might respond faster