13–17 Feb 2023
Faculty of Geoscience and Geography
Europe/Zurich timezone

A kaleidoscopic analysis of archival sedimentary macro-charcoal samples for reconstructing prehistoric and contemporary fire activity in South Africa

15 Feb 2023, 09:20
15m
MN09 (Faculty of Geoscience and Geography)

MN09

Faculty of Geoscience and Geography

Göttingen, Germany
Online short talk Data-based perspectives, problems, solutions Data-based perspectives, problems, solutions

Speaker

Abraham Dabengwa (GNOI)

Description

Charcoal from sedimentary archives is widely used to reconstruct landscape vegetation-fire relationships from modern and ancient landscapes. Digital image analysis is speeding up measurements of sedimentary macro-charcoal, (i.e., grains or particles > ~125—10 000µm). Fire reconstructions now boast higher spatial, temporal, and stratigraphic resolutions. Also, the scope of charcoal analysis has widened to include the determination of fuel-related metrics. However, the reliability and consistency of charcoal metrics across different laboratory processing methods remains untested. There is also underlying variation in how researchers quantify charcoal. Neglecting the study of these key variables may compromise the robustness of charcoal interpretations. Therefore, this initiative funded by the Past Global Changes Inter-Africa mobility grant (PAGES-IAM) aimed to achieve a re-analysis of fire-fuel-type-biomass relationships from charcoal metrics from grassy ecosystems across grazing density, climate, and temporal gradients. We conducted supervised and unsupervised charcoal edge-detection analysis of matched archival imaged samples using Chartool v.1 to from three laboratory methods. We plan to present our preliminary results and discuss how they relate to previous multi-proxy interpretations. We hope to extend this study by developing more training datasets to assist bulk machine-based object-based image analysis (OBIA) to quickly fingerprint the diversity of local and landscape fire regimes from grassy ecosystems

Primary author

Co-authors

Ms Enele Twala (University of the Witwatersrand) Dr Jemma Finch (University of KwaZulu-Natal) Prof. Marion Bamford (University of the Witwatersrand) Ms Megan Govender (University of the Witwatersrand) Prof. Sally Archibald (University of the Witwatersrand)

Presentation materials

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