Ethnobotanic and forage uses of plants on mine properties in the Witwatersrand Basin gold fields, South Africa

摘要

The disturbance and contamination of land attributable to over 120 years of gold mining activities in South Africa requires a critical evaluation of current and potential land-use options. The poor often depend on natural resources that they harvest themselves, or purchase at low prices. People utilise wild plants and other natural resources from mine properties and neighbouring lands, but the extent and impact of these activities is uncertain. This report describes the first phase of a study assessing the levels, safety and suslainability of informal harvesting from the properties of large gold and uranium mines situated in the Witwatersrand. Plant species and harvesting sites are being identified to enable assessment of plant populations for natural resource management purposes and to evaluate the potential safety of the consumption of plants harvested from polluted substrata by humans or animals. The study will also contribute to the development of regional protocols for attaining indigenous plant conservation objectives and sustainable land-use, with a particular focus on incorporating the needs of resource-poor members of society. In addition to managing large properties, the mines are implementing various phytotechnologies to control seepage and dust from tailings storage facilities (TSFs), and remediate polluted soils and groundwater. It is important that the plant species grown on such sites are not overly attractive to informal harvesters and herbivores, as this would disturb rehabilitation efforts and carry a potential risk to consumers. In this desktop study, records were obtained for 340 of the 900 plant species previously identified on two gold mining properties. Of the 340 species, 77.4% are used in traditional medicine; 19.4% for food; 16.7% for livestock fodder; 8.5% for building materials; 5.3% for veterinary uses; 5.0% for fuelwood; 5.0% for furniture and/or household implements; 4.4%for a range of uses (tanning, dyes, bleach, pest repellents, insecticides and perfume); 2.4% for weaving and 2.1% as general timber. Most species had multiple uses, with the most highly utilised families being the Asteraceae (14.5%); Poaceae (10.1%) and Fabaceae (7.9%).