| Dubbert, M; Cuntz, M; Piayda, A; Werner, C: Oxygen isotope signatures of transpired water vapor – the role of isotopic non-steady-state transpiration under natural conditions, New Phytologist (2014) | |
| Abstract: • The oxygen isotope signature of water is a powerful tracer of water movement from plants to the global scale. However, little is known on the short-term variability of oxygen isotopes leaving the ecosystem via transpiration as high-frequency measurements are lacking. • A laser spectrometer was coupled to a gas-exchange chamber directly estimating branch-level fluxes in order to evaluate the short-term variability of the isotopic composition of transpiration (δE) and to investigate the role of isotopic non-steady-state under natural conditions in cork-oak trees (Quercus suber L.) during distinct Mediterranean seasons. • Measured 18O of transpiration (δE) deviated from isotopic steady-state throughout most of the day even when leaf water at the evaporating sites was near isotopic steady-state. High agreement was found between estimated and modeled δE assuming non-steady-state enrichment of leaf water. • Isoforcing, i.e. the influence of the transpirational 18O flux on atmospheric values, deviated from steady-state calculations but daily means were similar between steady-state and non-steady-state. However, strong daytime isoforcing on the atmosphere imply that short-term variations in δE have likely consequences for large-scale applications, e.g. partitioning of ecosystem fluxes or satellite-based applications. |
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| Antrittsvorlesung: |
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| Mi. 22.05.2024 Funktionelle Pilzökologie: Diversität und Prozesse auf unterschiedlichen Skalen |
| BayCEER-Kolloquium: |
| Do. 06.06.2024 Tracking plant diversity dynamics on islands over thousands of years |
| Mo. 10.06.2024 Arsenic biogeochemistry from paddy soil to rice grain |
| Do. 13.06.2024 Seeing the forest beneath the trees: Mycorrhizal fungi as trait integrators of ecosystem processes |
| Ökologisch-Botanischer Garten: |
| Mi. 29.05.2024 Führung | "Grüne Apotheke: Heilpflanzen" |