EGU21-5417, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Climate and land-use effects on hydrological and vegetation signals during the last three millennia in southwestern Morocco

Asmae Baqloul1, Enno Schefuß2, Martin Kölling2, Lydie Dupont2, Jeroen Groeneveld3, Xueqin Zhao2, Hanane Reddad4, Lhoussaine Bouchaou1,5, and Ilham Bouimetarhan1,2,6
Asmae Baqloul et al.
  • 1Applied Geology and Geo-Environment Laboratory, Faculty of Sciences, Ibn Zohr University, Agadir, Morocco
  • 2MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
  • 3Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Telegrafenberg A45, D-14473 Potsdam, Germany
  • 4Ecole Supérieure de Technologie de Beni Mellal , University Sultan Moulay Slimane, Beni Mellal, Morocco
  • 5International Water Research Institute (IWRI), Mohammed VI Polytechnic University, Benguerir, Morocco
  • 6Faculté des sciences appliquées, CUAM, Ibn Zohr University of Agadir, Morocco

The southwest of Morocco is considered to be an area of refuge within the Mediterranean region, hosting the endemic tropical Argan tree. This region is presently subject to severe droughts, desertification, and land degradation, and likely facing increased climate variability and socio-economic stress in the future. Here, we use the stable hydrogen and carbon isotope composition (δD and δ13C) of plant-waxes in a high-resolution marine sediment core (GeoB8601-3) collected off Cape Ghir in southwestern Morocco, in combination with published data on pollen and XRF element ratios from the same archive. We aim to reconstruct the hydroclimate and vegetation history during the last 3000 years. Stable carbon isotope compositions of leaf waxes (δ13Cwax) show that natural vegetation in southwestern Morocco consists of C3 plants. Minor variations in δ13Cwax were positively correlated to changes in stable hydrogen isotope compositions of leaf waxes (δDwax) before 700 CE. Changes in rainfall amounts and water use efficiency indicate a clear vegetation response to precipitation changes and thus to climate forcing. After 700 CE, δDwax and δ13Cwax became de-coupled suggesting that the plant wax discharge and their isotope signals were no longer solely controlled by climate; the waxes likely mainly originate from the lowlands and carry an enriched (dry) δD signal but a depleted 13C signature. The depletion of δ13Cwax correlates with the increase of Argan pollen concentration in the record. The period between ~700 and 900 CE coincides with the Arabization of Morocco which had an impact on the demographic composition of the country leading to new agricultural habits and, as a result, on the land-use triggering a higher erosion of lowland material by the Souss River.

How to cite: Baqloul, A., Schefuß, E., Kölling, M., Dupont, L., Groeneveld, J., Zhao, X., Reddad, H., Bouchaou, L., and Bouimetarhan, I.: Climate and land-use effects on hydrological and vegetation signals during the last three millennia in southwestern Morocco, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5417,, 2021.

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