- Title
- Exploring the impact of sub-ambient CO2 concentrations on Oxalis growth: implications for food sustainability among Pleistocene human foragers in the Greater Cape Floristic Region
- Creator
- Faltein-Maqubela, Zintle
- ThesisAdvisor
- Ripley, Bradford Sherman
- ThesisAdvisor
- Midgley, Guy
- ThesisAdvisor
- Esler, Karen J
- Subject
- Carbon dioxide Thermal properties
- Subject
- Geophyte
- Subject
- Hunting and gathering societies Pleistocene
- Subject
- Paleobotany Pleistocene
- Subject
- Oxalis
- Subject
- Prehistoric peoples Food
- Subject
- Cape Floristic Kingdom
- Date
- 2025-04-02
- Type
- Academic theses
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10962/479097
- Identifier
- vital:78260
- Description
- Humans inhabiting the glacial refugia of the Cape Floristic Region during the Middle Pleistocene are believed to have relied on underground storage organs (USOs) as a crucial carbohydrate source. While previous research has highlighted the nutritional potential of these plants for early human gatherers, such studies are typically conducted under modern climatic conditions and do not account for the reduced plant productivity and USO yields associated with the lower atmospheric CO₂ concentrations characteristic of Pleistocene glacial periods. To evaluate the impact of CO₂ availability on plant productivity, I cultivated two Oxalis species—O. pes-caprae and O. punctata, both known to have been harvested by early foragers—under CO₂ concentrations ranging from 180 ppm to 400 ppm. Results showed that glacial-level CO₂ concentrations significantly reduced bulb production in O. pes-caprae and photosynthetic rates in both species. Using these findings to model Pleistocene foraging behaviour, I estimate that human foragers would have needed to spend an additional 8 hours gathering food to meet their daily dietary requirements of 2000 calories, suggesting the need for alternative food sources to supplement their diet. These findings emphasise the importance of considering historical plant growth conditions, particularly atmospheric CO₂ levels, when reconstructing past human diets. Failure to account for these factors may represent a significant gap in our understanding of human subsistence strategies during glacial periods.
- Description
- Thesis (MSc) -- Faculty of Science, Botany, 2025
- Format
- computer, online resource, application/pdf, 1 online resource (77 pages), pdf
- Publisher
- Rhodes University, Faculty of Science, Botany
- Language
- English
- Rights
- Faltein-Maqubela, Zintle
- Rights
- Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/)
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RU Department of Botany
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | FALTEIN-MAQUBELA-MSC-TR25-31.pdf | 1 MB | Adobe Acrobat PDF | View Details Download |