Seasonal availability of edible underground and aboveground carbohydrate resources to human foragers on the Cape south coast, South Africa
- Published
- Accepted
- Subject Areas
- Anthropology, Ecology, Evolutionary Studies
- Keywords
- Cape Floristic Region, cognitively modern humans, edible fruit, geophytes, Renosterveld, Strandveld, Fynbos, underground storage organs, hunter-gatherers
- Copyright
- © 2015 De Vynck et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. Seasonal availability of edible underground and aboveground carbohydrate resources to human foragers on the Cape south coast, South Africa. PeerJ PrePrints 3:e1379v1 https://doi.org/10.7287/peerj.preprints.1379v1
Abstract
The coastal environments of South Africa’s Cape Floristic Region (CFR) provide some of the earliest and most abundant evidence for the emergence of cognitively modern humans. In particular, the south coast of the CFR provided for hunter-gatherers a uniquely diverse resource base, namely marine shellfish, game, and carbohydrate-bearing plants, especially those with underground storage organs (USOs). It has been hypothesized that these resource underpinned the continuity of human occupation in the region since the Middle Pleistocene. Very little research has been conducted on the foraging potential of carbohydrate resources in the CFR. This study focuses on the seasonal availability of plants with edible carbohydrate by assessing their visibility to foragers at six-weekly intervals over a two-year period in four vegetation types on South Africa’s Cape south coast. A total of 52 edible plant species were recorded across all vegetation types. Of these, 33 species were geophytes with edible USOs and 21 species had aboveground edible carbohydrates. Limestone Fynbos had the richest flora, followed by Strandveld, Renosterveld and lastly, Sand Fynbos. The availability of USO species differed across vegetation types and between survey years. The number of available USO species was highest for a six-month period from winter to early summer (Jul-Dec) across all vegetation types. Months of lowest species’ availability were in mid-summer to early autumn (Jan-Apr); the early winter (May-Jun) values were variable, being highest in Limestone Fynbos. However, even during the late summer carbohydrate “crunch”, 25 carbohydrate bearing species were visible across the four vegetation types. Overall, the plant-based carbohydrate resources available to Stone Age foragers of the Cape south coast, especially USOs belonging to the Iridaceae family, are likely to have comprised a reliable and nutritious source of calories over most of the year. The winter and early spring months likely coincided with a scarcity of protein, especially marine invertebrates, but an abundance of carbohydrates. At these times, plant carbohydrates, especially USOs, may have comprised 100% of dietary intake. However, recognising which vegetation types are most productive, identifying hotspots of productivity and distinguishing between edible and toxic USOs must have required considerable cognitive skills.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Biophysical data, species summaries, explanation of acronyms listed in Fig. 4, climate diagrams of the four study sites and pheno-diagrams of all species encountered in the four study sites
Table S1: Biophysical data for the four study sites. Table S2. List of edible plant species found in each plot situated within a prominent vegetation type along the southern Cape lowlads of South Africa. The list is divided into underground storage organs and aboveground carbohydrates. Table S3.1. Species list of USOs (on left) and fruiting species (aboveground carbohydrate resources) (on right) and their acronyms encountered in the Phenology survey of the four basic vegetation types of the southern Cape lowlands to coastal margin. Table S3.2 Species list summary of USOs (on left) and fruiting species (aboveground carbohydrate resources) (on right) and their acronyms encountered in the Phenology survey of the four basic vegetation types of the southern Cape lowlands to coastal margin. Fig. S1. Climate diagrams showing temperature and rainfall patterns for the study sites during the survey period (May 2010-April 2012). Mean values of temperature and rainfall are shown in parentheses.
Explanation of columns in raw data file
This file is an explanation of "De Vynck et al. raw data". It contains descriptions of columns and detail on data collection.
Raw data collected six-weekly over two years in the four primary vegetation types, southern Cape, South Africa
The raw data are six-weekly counts, over two years, of edible plants with underground storage organs and aboveground edibles. These surveys were performed in predesignated 3.6 hectare plots of the four primary vegetation types of the southern Cape, South Africa.
Indigenous Edible Plant Use by Contemporary Khoe-San Descendants of South Africa’s Cape South Coast
The paper is in press (South African Journal of Botany) and was cited in this submitted paper to PeerJ. De Vynck et al. in press reports on an ethno-botanical survey which was performed in the southern Cape, South Africa.