Alexandre, Anne (2025): Phytolith isotopes from West Africa (Benin and Senegal) [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.986640 (DOI registration in progress), In: Alexandre, A (2025): Climate and triple oxygen isotope of precipitation, groundwater, soil water, plant water, and phytolith data from West Africa (Benin and Senegal) [dataset bundled publication]. PANGAEA, https://doi.org/10.1594/PANGAEA.984133
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Published: 2025-11-24
Abstract:
Triple oxygen isotope composition of phytoliths extracted from grass stems and leaves collected at Belefoungou (BE, Benin), Nalohou (NA, Benin) and Dahra (DA, Senegal). Descriptors of the grass samples and phytolith concentration are presented. Atmospheric relative humidity and air temperature averages are calculated for the grass growing season. Phytolith-water fractionation coefficients are calculated for stem phytoliths. Observed and predicted values (using fractionation values from Dodd and Sharp, 2011 and Outrequin et al., 2021) can be compared.
Related to:
Alexandre, Anne; Outrequin, Clément; Vallet-Coulomb, Christine; Peugeot, Christophe; Grippa, Manuela; Aleman, Julie C; Voigt, Claudia; Landais, Amaëlle; Mougin, Eric; Ndiaye, Ousmane; Sonzogni, Corinne; Yang, David Au; Mazur, Jean-Charles; Couapel, Martine; Ogée, Jérôme; Ouani, Theodore; Afouda, Simon; Wubda, Maxime; Soumaguel, Nogmana; Houngnon, Alfred; Tagesson, Torbern; Fensholt, Rasmus (2025): What Does the Triple Isotopic Composition of Oxygen in Precipitation, Groundwater, Soil Water, Plant Water, and Phytoliths Reveal About Current and Past Hydrological Cycles? Journal of Geophysical Research: Biogeosciences, 130(10), e2024JG008615, https://doi.org/10.1029/2024JG008615
References:
Dodd, Justin P; Sharp, Zachary D (2010): A laser fluorination method for oxygen isotope analysis of biogenic silica and a new oxygen isotope calibration of modern diatoms in freshwater environments. Geochimica et Cosmochimica Acta, 74(4), 1381-1390, https://doi.org/10.1016/j.gca.2009.11.023
Outrequin, Clément; Alexandre, Anne; Vallet-Coulomb, Christine; Piel, Clément; Devidal, Sébastien; Landais, Amaëlle; Couapel, Martine; Mazur, Jean-Charles; Peugeot, Christophe; Pierre, Monique; Prié, Frédéric; Roy, Jacques; Sonzogni, Corinne; Voigt, Claudia (2021): The triple oxygen isotope composition of phytoliths, a new proxy of atmospheric relative humidity: controls of soil water isotope composition, temperature, CO 2 concentration and relative humidity. Climate of the Past, 17(5), 1881-1902, https://doi.org/10.5194/cp-17-1881-2021
Funding:
Agence Nationale de la Recherche (ANR), grant/award no. ANR-17-CE01-0002: Past dynamic of continental atmospheric humidity and vegetation: new insights from the triple isotopic composition of oxygen (HUMI-17)
Coverage:
Median Latitude: 11.624000 * Median Longitude: -4.060667 * South-bound Latitude: 9.733000 * West-bound Longitude: -15.482000 * North-bound Latitude: 15.356000 * East-bound Longitude: 1.700000
Date/Time Start: 2018-04-04T00:00:00 * Date/Time End: 2028-12-08T00:00:00
Event(s):
Bellefoungou_met * Latitude: 9.733000 * Longitude: 1.600000 * Location: Bellefoungou, Benin * Method/Device: Meteorological station * Comment: AMMA-CATCH Meteorological station
Comment:
Soils and plants were collected in 4m2 fenced sampling plots a few meters from the meteorological stations
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Event label | Event | Alexandre, Anne | |||
| 2 | Location | Location | Alexandre, Anne | |||
| 3 | Vegetation type | Vegetation type | Alexandre, Anne | Field survey | ||
| 4 | Sample code/label | Sample label | Alexandre, Anne | |||
| 5 | DATE/TIME | Date/Time | Alexandre, Anne | Geocode – Date | ||
| 6 | Comment | Comment | Alexandre, Anne | when no date defined | ||
| 7 | Period | Period | Alexandre, Anne | Field survey | Estimated growing period | |
| 8 | Type | Type | Alexandre, Anne | Field survey | Sample type | |
| 9 | Species | Species | Alexandre, Anne | Botanical inventory | ||
| 10 | Comment | Comment | Alexandre, Anne | Field survey | Growing vs senescent | |
| 11 | Vegetation height | Veg h | cm | Alexandre, Anne | Field survey | |
| 12 | Phytoliths | Phytoliths | % | Alexandre, Anne | Chemical extraction | Phytolith concentration (% dry weight) |
| 13 | Percentage | Perc | % | Alexandre, Anne | Microscopy counting | Long cell phytolith proportion LC |
| 14 | δ18O, phytolith | δ'18O phytolith | ‰ SMOW | Alexandre, Anne | Fluorination-IR laser-Isotope ratio mass spectrometry | average, vs VSMOW |
| 15 | δ'18O, phytolith | δ'18O phytolith | ‰ SMOW | Alexandre, Anne | Fluorination-IR laser-Isotope ratio mass spectrometry | average, vs VSMOW |
| 16 | δ'18O, phytolith, standard deviation | δ'18O phytolith std dev | ± | Alexandre, Anne | Fluorination-IR laser-Isotope ratio mass spectrometry | |
| 17 | δ'17O, phytolith | δ'17O phytolith | ‰ SMOW | Alexandre, Anne | Fluorination-IR laser-Isotope ratio mass spectrometry | average, vs VSMOW |
| 18 | δ'17O, phytolith, standard deviation | δ'17O phytolith std dev | ± | Alexandre, Anne | Fluorination-IR laser-Isotope ratio mass spectrometry | |
| 19 | Oxygen-17 excess, phytolith | 17O xs phytolith | per meg | Alexandre, Anne | Fluorination-IR laser-Isotope ratio mass spectrometry | average |
| 20 | Oxygen-17 excess, phytolith, standard deviation | 17O xs phytolith std dev | ± | Alexandre, Anne | Fluorination-IR laser-Isotope ratio mass spectrometry | |
| 21 | Number of analyses | N analyses | # | Alexandre, Anne | Fluorination-IR laser-Isotope ratio mass spectrometry | |
| 22 | Humidity, relative, daily mean | RH day m | % | Alexandre, Anne | Meteorological station, AMMA-CATCH | Rainy season |
| 23 | Humidity, relative, daily mean | RH day m | % | Alexandre, Anne | Calculation using AMMA-CATCH metorological data | Phytolith production weighted-rainy season daily relative humidity |
| 24 | Temperature, air, daily mean | TTT day m | °C | Alexandre, Anne | Calculation using AMMA-CATCH metorological data | Phytolith production weighted-rainy season daily air temperature |
| 25 | Humidity, relative, daytime mean | RH daytime m | % | Alexandre, Anne | Calculation using AMMA-CATCH metorological data | Rainy season |
| 26 | Humidity, relative, daytime mean | RH daytime m | % | Alexandre, Anne | Calculation using AMMA-CATCH metorological data | Phytolith production weighted-rainy season daytime relative humidity |
| 27 | Temperature, air, daytime mean | TTT daytime m | °C | Alexandre, Anne | Calculation using AMMA-CATCH metorological data | Phytolith production weighted-rainy season daytime air temperature |
| 28 | Temperature, leaf, daily mean | T leaf day m | °C | Alexandre, Anne | Calculation using AMMA-CATCH metorological data | Phytolith production weighted-rainy season daily leaf temperature |
| 29 | δ'18O, precipitation | δ'18O precip | ‰ SMOW | Alexandre, Anne | Calculation using precipitation isotopes | Phytolith production-weighted d'18Oprecipitation, vs VSMOW |
| 30 | δ'17O, precipitation | δ'17O precip | ‰ SMOW | Alexandre, Anne | Calculation using precipitation isotopes | Phytolith production-weighted d'17Oprecipitation, vs VSMOW |
| 31 | Oxygen-17 excess, precipitation | 17O xs precip | per meg | Alexandre, Anne | Calculation using precipitation isotopes | Phytolith production-weighted 17O-excessprecipitation |
| 32 | Δδ'18O | Δδ'18O | ‰ | Alexandre, Anne | Calculation using phytolith and precipitation isotopes | Observed D'18Ostem phytolith - precipitation |
| 33 | Δδ'17O | Δδ'17O | ‰ | Alexandre, Anne | Calculation using phytolith and precipitation isotopes | Observed D'17Ostem phytolith - precipitation |
| 34 | Δ Oxygen-17 excess | Δ17O xs | per meg | Alexandre, Anne | Calculation using phytolith and precipitation isotopes | Observed D17O-excessphytolith - precipitation |
| 35 | Isotopic fractionation | lambda | Alexandre, Anne | Calculation using phytolith and precipitation isotopes | (d'^17O_stem phytolith -d'^17 O_precipitation ) /(d'^17O_stem phytolith -d'^17O_precipitation ) | |
| 36 | Δδ'18O | Δδ'18O | ‰ | Alexandre, Anne | Calculation using phytolith and precipitation isotopes | Estimated D'18Ostem phytolith - precipitation (‰) |
| 37 | Δδ'17O | Δδ'17O | ‰ | Alexandre, Anne | Calculation using phytolith and precipitation isotopes | Estimated D'17O-excessphytolith - precipitation (‰) |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0)
Status:
Curation Level: Enhanced curation (CurationLevelC)
Size:
922 data points