What Does the Triple Isotopic Composition of Oxygen in Precipitation, Groundwater, Soil Water, Plant Water, and Phytoliths Reveal About Current and Past Hydrological Cycles?
(2025) In Journal of Geophysical Research: Biogeosciences 130(10).- Abstract
Quantitative data are needed to constrain the feedback loops between vegetation and hydroclimate. In this study, the amplitudes of variations in the triple oxygen isotope composition of water at the soil-plant-atmosphere interface are measured in savanna and dry forest contexts in West Africa (Benin and Senegal). Comparison of in situ data and model estimates reveals the following: (a) The value of 17O-excess for reconstructing climate archives is confirmed, given its small variability in precipitation (a few per meg) compared to the very large magnitude of change in the 17O-excess of phytoliths (hundreds of per meg) in response to RH changes. (b) At the beginning of the dry season, the 17O-excess in... (More)
Quantitative data are needed to constrain the feedback loops between vegetation and hydroclimate. In this study, the amplitudes of variations in the triple oxygen isotope composition of water at the soil-plant-atmosphere interface are measured in savanna and dry forest contexts in West Africa (Benin and Senegal). Comparison of in situ data and model estimates reveals the following: (a) The value of 17O-excess for reconstructing climate archives is confirmed, given its small variability in precipitation (a few per meg) compared to the very large magnitude of change in the 17O-excess of phytoliths (hundreds of per meg) in response to RH changes. (b) At the beginning of the dry season, the 17O-excess in soil water is lower than that of precipitation by only 30 per meg in the sandy-loam soils and 50 per meg in the sandy soil. This shows the limited contribution of evaporated water to bulk soil water and provides clues to constrain the complex hydrological functioning of soils; (c) The regression line connecting the triple oxygen isotope composition of water in the stems and leaves of grasses and trees can be used to determine the origin of the water absorbed by the roots. Semi-evergreen trees draw their water from the water table during the dry season, whereas grasses and semi-evergreen trees use surface water during the wet season. These original data open up new perspectives for the use of the triple oxygen isotope composition of water and phytoliths to better understand current and past hydrological cycles.
(Less)
- author
- organization
- publishing date
- 2025-10
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- hydroclimate, past climate, phytolith, relative humidity, triple oxygen isotopes, water cycle
- in
- Journal of Geophysical Research: Biogeosciences
- volume
- 130
- issue
- 10
- article number
- e2024JG008615
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:105019205857
- ISSN
- 2169-8953
- DOI
- 10.1029/2024JG008615
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2025. The Author(s).
- id
- d5e09e8b-be6f-49e9-b76c-5d8a49e27a65
- date added to LUP
- 2025-12-18 10:15:04
- date last changed
- 2025-12-18 14:36:41
@article{d5e09e8b-be6f-49e9-b76c-5d8a49e27a65,
abstract = {{<p>Quantitative data are needed to constrain the feedback loops between vegetation and hydroclimate. In this study, the amplitudes of variations in the triple oxygen isotope composition of water at the soil-plant-atmosphere interface are measured in savanna and dry forest contexts in West Africa (Benin and Senegal). Comparison of in situ data and model estimates reveals the following: (a) The value of <sup>17</sup>O-excess for reconstructing climate archives is confirmed, given its small variability in precipitation (a few per meg) compared to the very large magnitude of change in the <sup>17</sup>O-excess of phytoliths (hundreds of per meg) in response to RH changes. (b) At the beginning of the dry season, the <sup>17</sup>O-excess in soil water is lower than that of precipitation by only 30 per meg in the sandy-loam soils and 50 per meg in the sandy soil. This shows the limited contribution of evaporated water to bulk soil water and provides clues to constrain the complex hydrological functioning of soils; (c) The regression line connecting the triple oxygen isotope composition of water in the stems and leaves of grasses and trees can be used to determine the origin of the water absorbed by the roots. Semi-evergreen trees draw their water from the water table during the dry season, whereas grasses and semi-evergreen trees use surface water during the wet season. These original data open up new perspectives for the use of the triple oxygen isotope composition of water and phytoliths to better understand current and past hydrological cycles.</p>}},
author = {{Alexandre, Anne and Outrequin, Clement and Vallet-Coulomb, Christine and Peugeot, Christophe and Grippa, Manuela and Aleman, Julie and Voigt, Claudia and Landais, Amaelle and Mougin, Eric and Ndiaye, Ousmane and Sonzogni, Corinne and Yang, David Au and Mazur, Jean Charles and Couapel, Martine and Ogée, Jérôme and Ouani, Theodore and Afouda, Simon and Wubda, Maxime and Soumaguel, Nogmana and Houngnon, Alfred and Tagesson, Torbern and Fensholt, Rasmus}},
issn = {{2169-8953}},
keywords = {{hydroclimate; past climate; phytolith; relative humidity; triple oxygen isotopes; water cycle}},
language = {{eng}},
number = {{10}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Journal of Geophysical Research: Biogeosciences}},
title = {{What Does the Triple Isotopic Composition of Oxygen in Precipitation, Groundwater, Soil Water, Plant Water, and Phytoliths Reveal About Current and Past Hydrological Cycles?}},
url = {{http://dx.doi.org/10.1029/2024JG008615}},
doi = {{10.1029/2024JG008615}},
volume = {{130}},
year = {{2025}},
}