Late Quaternary climate and environmental reconstruction based on lake and peat sediments from the central southern Cape region of South Africa
Final Report Abstract
The aim of this project was to substantially improve our understanding of Late Quaternary paleoenvironmental dynamics in southern Africa, particularly in the southern Cape region. To achieve this, a high-resolution multi-proxy approach was applied to sediment sequences from Vankervelsvlei (a fen) and Voёlvlei (a coastal lake), covering the Holocene and parts of Marine Isotope Stage (MIS) 3. These archives represent rare but highly valuable records in a region where natural sedimentary archives are scarce and often discontinuous. Within this project, a previously recovered 14.6 m core from Vankervelsvlei and a 13 m core from Voёlvlei were analysed using a consistent methodological framework. This included elemental and grain-size analyses, as well as compound-specific stable isotope analyses of leaf wax-derived n-alkanes (δ²H) and hemicellulose-derived sugars (δ¹⁸O). This dual-isotope “paleohygrometer” approach enables quantitative reconstructions of precipitation sources, relative humidity, and evapotranspiration, key climatic parameters that have previously been overlooked or unresolved in the region. At Vankervelsvlei, Holocene fire and hydroclimate dynamics were reconstructed using macro-charcoal and PAH data alongside isotopic records. The results indicate complex shifts in rainfall seasonality, with alternating dominance of Westerly-derived winter and Easterly/local summer rainfall over the past 7200 years, linked to regional moisture balance and fire activity. Large-scale climate modes, such as El Niño, likely played a role in modulating short-term hydroclimate variability. The long-term Vankervelsvlei record additionally provided insight into the last ~250 ka. The driest conditions occurred during MIS 6–5e and 2, whereas MIS 5a and parts of MIS 3 were relatively moist. Glacial–interglacial shifts in precipitation source and sea-level-induced changes in continentality strongly influenced hydrological balance and sedimentation. The Voëlvlei core, covering 8500 years, complements these findings. It documents a marine phase during the early Holocene and subsequent transitions from Westerly- to Easterlydominated rainfall, with several abrupt hydroclimatic shifts. These trends are consistent with other regional studies and highlight the dynamic interplay between precipitation source, seasonality, and moisture availability through the Holocene. In addition, surface soil studies across modern environmental gradients tested the reliability of the paleohygrometer approach. While δ²H of n-alkanes correlated well with precipitation isotopes, δ¹⁸O of sugars was strongly influenced by evapotranspiration. In ecosystems dominated by non-CAM plants, reconstructed δ²H, δ¹⁸O, and relative humidity showed good agreement with observed values. In summary, the project generated new high-resolution records and methodological innovations, confirming that Late Quaternary climate in the southern Cape was markedly more variable than previously assumed.
Link to the final report
http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/15385
Publications
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Calibration of δ2Hn-alkane and δ18Osugar for paleoclimate reconstructions in South Africa and its first application to peat sediments from Vankervelsvlei. EGU General Assembly 2020. 3-8 May 2020, Vienna, Austria. Online.
Strobel, P., R. Zech, M. Bliedtner, J. Struck, B. Glaser, M. Zech, M. Meadows & T. Haberzettl
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The potential of δ2H-alkanes and δ18Osugar for paleoclimate reconstruction – A regional calibration study for South Africa. Science of The Total Environment, 716, 137045.
Strobel, P.; Haberzettl, T.; Bliedtner, M.; Struck, J.; Glaser, B.; Zech, M. & Zech, R.
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Advantages of compound-specific isotopes to reconstruct paleohydrological changes at South Africa’s southern Cape coast during the Holocene. Mid-European Geomorphology Meeting 2021, 5-9 November, Munich, Germany.
Strobel, P., M. Bliedtner, A. Carr, N. du Plessis, B. Glaser, B. Klaes, L. Quick, G. Salazar, J. Struck, S. Szidat, M. Zech, R. Zech & T. Haberzettl
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Calibration and Application of Molecular Biomarker Isotopes to Reconstruct Palaeohydrological Changes at South Africa’s Southern Cape Coast During the Holocene. Virtual DEUQUA 2021. 30 September - 1 October 2021, online.
Strobel, P., M. Bliedtner, A. Carr, N. Du Plessis, B. Glaser, B. Klaes, L. Quick, G. Salazar, J. Struck, S. Szidat, M. Zech, R. Zech & T. Haberzettl
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Holocene sea level and environmental change at the southern Cape – an 8.5 kyr multi-proxy paleoclimate record from Lake Voëlvlei, South Africa. Climate of the Past, 17(4), 1567-1586.
Strobel, Paul; Bliedtner, Marcel; Carr, Andrew S.; Frenzel, Peter; Klaes, Björn; Salazar, Gary; Struck, Julian; Szidat, Sönke; Zech, Roland & Haberzettl, Torsten
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Reconstructing Late Quaternary precipitation and its source on the southern Cape coast of South Africa: A multi-proxy paleoenvironmental record from Vankervelsvlei. Quaternary Science Reviews, 284, 107467.
Strobel, P.; Bliedtner, M.; Carr, A.S.; Struck, J.; du Plessis, N.; Glaser, B.; Meadows, M.E.; Quick, L.J.; Zech, M.; Zech, R. & Haberzettl, T.
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Holocene hydroclimatic and fire dynamics on the southern Cape coast of South Africa - A 7.2 ka multi-biomarker record from the peatland Vankervelsvlei. XXI INQUA Congress. 14-20 July, Rome, Italy.
Strobel, P., T. Henning, M. Bliedtner, K. Kirsten, S.G. Mosher, H. Rahimova, T. Haberzettl, E. Lehndorff, M. Power, M. Zech & R. Zech
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Holocene fire dynamics and their climatic controls on the southern Cape coast of South Africa - A 7.2 ka multi-proxy record from the peatland Vankervelsvlei. Quaternary Science Reviews, 325, 108464.
Strobel, Paul; Henning, Theresa; Bliedtner, Marcel; Mosher, Stella G.; Rahimova, Humay; Haberzettl, Torsten; Kirsten, Kelly L.; Lehndorff, Eva; Power, Mitchell J.; Zech, Michael & Zech, Roland
