Publication Details
Category Text Publication
Reference Category Journals
DOI 10.1111/nph.12878
Title (Primary) Oxygen isotope signatures of transpired water vapor: the role of isotopic non-steady-state transpiration under natural conditions
Author Dubbert, M.; Cuntz, M.; Piayda, A.; Werner, C.
Source Titel New Phytologist
Year 2014
Department CHS
Volume 203
Issue 4
Page From 1242
Page To 1252
Language englisch
Keywords isotopic non-steady-state transpiration; isotopic steady-state transpiration; laser spectrometer; oxygen isotopes; plant transpiration; Quercus suber
UFZ wide themes RU5;
Abstract
  • The oxygen isotope signature of water is a powerful tracer of water movement from plants to the global scale. However, little is known about 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 transpiration under natural conditions in cork-oak trees (Quercus suber) during distinct Mediterranean seasons.
  • The measured δ18O 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 values assuming non-steady-state enrichment of leaf water.
  • Isoforcing, that is, the influence of the transpirational δ18O 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 implies that short-term variations in δE are likely to have consequences for large-scale applications, for example, partitioning of ecosystem fluxes or satellite-based applications.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=14930
Dubbert, M., Cuntz, M., Piayda, A., Werner, C. (2014):
Oxygen isotope signatures of transpired water vapor: the role of isotopic non-steady-state transpiration under natural conditions
New Phytol. 203 (4), 1242 - 1252 10.1111/nph.12878