- Title
- Exploring the role of herbivory in Albany Subtropical Thicket restoration
- Creator
- Hunt, Kristen Louise
- Subject
- Shrubs -- South Africa
- Subject
- Portulacaria afra -- South Africa
- Subject
- Grasslands -- South Africa
- Subject
- Plant communities -- South Africa
- Date Issued
- 2024-04
- Date
- 2024-04
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/64060
- Identifier
- vital:73647
- Description
- This dissertation attempted to investigate the influence of herbivory on the success of thicket restoration, addressing a critical gap in the current knowledge within the restoration initiative. Despite two decades of thicket restoration practices, the role of herbivory in influencing restoration success has been assumed and not yet quantified. This research aimed to observe and identify herbivore species and their interactions that may affect the survival of Portulacaria afra Jacq. material planted in thicket restoration contexts. This research took place on three game farms serving as case studies within the Albany Subtropical Thicket (Eastern Cape, South Africa). Multiple experiments were conducted to assess how the concept of different “natural refugia” might impact herbivore interactions with planted material, incorporating factors such as planting around rainfall, within open and semi-intact vegetation patches, and in proximity to water sources. Trail cameras were used for real-time monitoring of herbivore interactions within planted sites to understand and quantify herbivore interactions with P. afra cuttings and how they may impact plant survival. Results from the trail camera monitoring (Chapter 2) indicate varied herbivore interactions occurring on planted material, with the primary herbivore responsible for these interactions varying among farms. Species interactions were not consistent across farms, and herbivore interactions exhibited spatial and temporal variability. Notably, interactions declined soon after the start of the wet phase when surrounding vegetation could recover, indicating the influences of alternative forage availability on herbivore foraging choices. Different herbivore interactions were identified and quantified through trail camera images, ranging from minor biomass removal (estimated at <5 cm of stem and leaf material) to more detrimental actions such as uprooting and leaf stripping. Consistently, planted P. afra survival rates (Chapter 3) were significantly higher for protected material than those exposed to herbivores, regardless of whether planted in a dry or wet phase. Moreover, when exposed to herbivores, rooted material had significantly higher survival rates than unrooted material, indicating the potential advantage of a well-developed root system in faster recovery after a herbivory event. This research explored the influence of various factors, including rainfall, rooting state, protection, surrounding vegetation, and proximity to water, on P. afra survival and how some of these factors may affect P. afra survival in relation to herbivore interactions (Chapter 3). Significant differences in cutting survival were observed between dry and wet phases, rooted and unrooted material, and material protected vs exposed to herbivores. While survival was not significantly different in experiments involving surrounding vegetation and proximity to water, potential patterns were identified, warranting further investigation. A clipping and defoliation experiment under simulated seasonal conditions emphasised the significance of
- Description
- Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (128 pages)
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
- Rights
- All Rights Reserved
- Rights
- Open Access
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Collections
NMU School of Environmental Sciences
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Hunt, KL.pdf | 5 MB | Adobe Acrobat PDF | View Details Download |