- Title
- Potential eco-physiological and phytosociological impacts of fracking on the vegetation of the Karoo, Eastern Cape, South Africa
- Creator
- Martin, Kristen
- Subject
- Hydraulic fracturing -- Environmental aspects -- South Africa -- Eastern Cape
- Subject
- Germination Plant ecology Plant communities
- Date Issued
- 2018
- Date
- 2018
- Type
- Thesis
- Type
- Doctoral
- Type
- DPhil
- Identifier
- http://hdl.handle.net/10948/31852
- Identifier
- vital:31853
- Description
- Hydraulic fracturing or fracking is a technique that is used to extract gas from low permeable rocks. Large volumes of fluids (typically water combined with chemicals and sand) are injected at high pressure into rock formations to fracture them, allowing the gas to be released. A number of criticisms have come to light regarding the potential environmental impacts of this process. One concern is that there will be contamination of groundwater due to the toxicity of the chemicals used in the fracking process. There have been limited studies on the effects of fracking fluid on vegetation and no studies on South African vegetation specifically. The effects of fracking chemicals on the germination success and photosynthetic efficiency of plants was investigated for species common in areas earmarked for possible future hydraulic fracturing in the Karoo, South Africa. Germination of seeds was unaffected by these fracking fluids at application concentration in most species, but dwarf shrub and grass seeds were found to be sensitive to contamination. A single application treatment of plants with fracking fluid resulted in mortality in 50% of the species with reduced photosynthetic efficiency and growth in some of the surviving species. Long term continual treatment with diluted fracking fluids had an even greater effect on mortality and photosynthetic efficiency than a single high dose. The major vegetation types of the proposed fracking footprint were surveyed and analyses of the species, communities and their physiognomy were used to predict the tolerance of the Karoo vegetation to degradation resulting from shale gas development. An understanding of the sensitivity of vegetation was obtained from impacts of livestock on the vegetation. The results indicated that Grassland communities are least tolerant to degradation, Albany Thicket communities more tolerant and Nama-Karoo communities most tolerant. Escarpment Thickets were shown to be Nama-Karoo rather than Albany Thicket elements, and should be grouped with the former when considering the impacts of fracking.
- Format
- xix, 217 leaves
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Kristen Martin.pdf | 5 MB | Adobe Acrobat PDF | View Details Download |