The Aardvark as an ecological engineer in the Eastern Karoo: dig patterns and emergent processes
- Martin, Stephanie Ann, Landman, Marietjie
- Authors: Martin, Stephanie Ann , Landman, Marietjie
- Date: 2017
- Subjects: Ecosystem services -- South Africa -- Eastern Cape Environmental engineering -- South Africa -- Eastern Cape Soil dynamics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11952 , vital:27010
- Description: Species which play particularly important roles in ecosystem patterns and processes are recognised as keystone species or ecosystem engineers. The conservation of these species is critical for the maintenance of the ecological role they play in ecosystem function. The aardvark, Orycteropus afer, is known to play a role in biopedturbation through digging for refuges and for prey, and as a consequence of these digging activities is expected to serve the role of an ecosystem engineer and keystone species. This study aimed to describe and quantify the ecological patterns and processes driven by the aardvark through their digging activities, within the eastern Karoo, and thereby evaluate the significance of aardvarks as ecosystem engineers and keystone species in a semi-arid environment. The landscape pattern (dig abundance and distribution) and soil displacement of aardvark forage and refuge digs in a semi-arid Karoo landscape, as well as the ecological processes (generating fertile, seed retention hotspots) driven by aardvark forage digs was measured. Refuge digs occurred in the highest densities in areas characterised by a specific suite of soil, vegetation and elevation features, while forage digs occurred in high abundance in most habitats measured, and were likely driven by prey availability. Forage digs served as litter and seed retention hotspots, with accelerated decomposition rates of litter as a function of increased soil moisture in digs. The functional processes (i.e. resource capture, shelter for plants and animals, germination sites, soil aeration, organic turnover, mineralization rates, fertile soil displacement and transport) driven by aardvark digs are not restricted to refuge digs. Forage digs occurred in most habitats measured and their functional role is unique and perhaps greater across the landscape in comparison to refuge digs. The aardvark has a disproportionate effect in ecosystems, in terms of its refuge and forage digs relative to its abundance and therefore its role as a keystone species and ecosystem engineer is confirmed. Conservation and protection of this species is therefore essential to maintain its important role in ecosystem function.
- Full Text:
- Date Issued: 2017
- Authors: Martin, Stephanie Ann , Landman, Marietjie
- Date: 2017
- Subjects: Ecosystem services -- South Africa -- Eastern Cape Environmental engineering -- South Africa -- Eastern Cape Soil dynamics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11952 , vital:27010
- Description: Species which play particularly important roles in ecosystem patterns and processes are recognised as keystone species or ecosystem engineers. The conservation of these species is critical for the maintenance of the ecological role they play in ecosystem function. The aardvark, Orycteropus afer, is known to play a role in biopedturbation through digging for refuges and for prey, and as a consequence of these digging activities is expected to serve the role of an ecosystem engineer and keystone species. This study aimed to describe and quantify the ecological patterns and processes driven by the aardvark through their digging activities, within the eastern Karoo, and thereby evaluate the significance of aardvarks as ecosystem engineers and keystone species in a semi-arid environment. The landscape pattern (dig abundance and distribution) and soil displacement of aardvark forage and refuge digs in a semi-arid Karoo landscape, as well as the ecological processes (generating fertile, seed retention hotspots) driven by aardvark forage digs was measured. Refuge digs occurred in the highest densities in areas characterised by a specific suite of soil, vegetation and elevation features, while forage digs occurred in high abundance in most habitats measured, and were likely driven by prey availability. Forage digs served as litter and seed retention hotspots, with accelerated decomposition rates of litter as a function of increased soil moisture in digs. The functional processes (i.e. resource capture, shelter for plants and animals, germination sites, soil aeration, organic turnover, mineralization rates, fertile soil displacement and transport) driven by aardvark digs are not restricted to refuge digs. Forage digs occurred in most habitats measured and their functional role is unique and perhaps greater across the landscape in comparison to refuge digs. The aardvark has a disproportionate effect in ecosystems, in terms of its refuge and forage digs relative to its abundance and therefore its role as a keystone species and ecosystem engineer is confirmed. Conservation and protection of this species is therefore essential to maintain its important role in ecosystem function.
- Full Text:
- Date Issued: 2017
The taxability of rewards from suppliers
- Authors: Akoonjie, Ahmed Hassen
- Date: 2016
- Subjects: Taxation -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/11253 , vital:26902
- Description: Successful business in today’s competitive climate thrives on building relationships with one’s suppliers, clientele and employees. Businesses, as a form of strategic engagement, extend their appreciation and recognition to these key role players with rewards (or incentives) such as prizes, holidays and free goods and/or services. This treatise examines the taxation implications of such rewards and determines that the market value thereof should be taxed in the hands of their recipients. This study also investigates possible indicators (or points of reference) to establish such market value and suggests alternate values that may be ascribed thereto for inclusion in the recipient’s gross income. Where the rewards are passed onwards by the recipient to its employees, fringe benefit consequences are occasioned and this study observes that the market value thereof should be taxed in the employees’ hands. The study goes on further to consider the position of the supplier (or provider) of the rewards and finds that the supplier is entitled to a deduction of the cost of the rewards it has provided to its clients or customers. This study also reflects upon the penal implications of not including the market value of rewards in gross income and notes that such non-inclusion constitutes a fiscal loss and is subject to an understatement penalty. Key recommendations on how such omission may be addressed by the tax authorities are also presented.
- Full Text:
- Date Issued: 2016
- Authors: Akoonjie, Ahmed Hassen
- Date: 2016
- Subjects: Taxation -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/11253 , vital:26902
- Description: Successful business in today’s competitive climate thrives on building relationships with one’s suppliers, clientele and employees. Businesses, as a form of strategic engagement, extend their appreciation and recognition to these key role players with rewards (or incentives) such as prizes, holidays and free goods and/or services. This treatise examines the taxation implications of such rewards and determines that the market value thereof should be taxed in the hands of their recipients. This study also investigates possible indicators (or points of reference) to establish such market value and suggests alternate values that may be ascribed thereto for inclusion in the recipient’s gross income. Where the rewards are passed onwards by the recipient to its employees, fringe benefit consequences are occasioned and this study observes that the market value thereof should be taxed in the employees’ hands. The study goes on further to consider the position of the supplier (or provider) of the rewards and finds that the supplier is entitled to a deduction of the cost of the rewards it has provided to its clients or customers. This study also reflects upon the penal implications of not including the market value of rewards in gross income and notes that such non-inclusion constitutes a fiscal loss and is subject to an understatement penalty. Key recommendations on how such omission may be addressed by the tax authorities are also presented.
- Full Text:
- Date Issued: 2016
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