Conservation incentives for private commercial farmers in the thicket biome, Eastern Cape, South Africa
- Authors: Cumming, Tracey Lyn
- Date: 2007
- Subjects: Landowners -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4745 , http://hdl.handle.net/10962/d1006953 , Landowners -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape
- Description: This study sought opportunities to mitigate the pressures of land transformation and alien invader plants on commercial farm land in the thicket biome in the lower reaches of the Fish Kowie Corridor. It had two aims. Firstly, to determine the role incentives could play in mitigating these pressures. Secondly, to determine the characteristics of an incentive programme that would most effectively achieve this. In order to do this, an understanding of landowner activities, needs, opinions and barriers to behaviour; the nature of the pressures on thicket and the nature of the required behaviour to reduce these pressures; and current and past institutional arrangements needed to be achieved. This was done predominantly through a current literature review and personal interviews with landowners and key informants. These findings were used to make recommendations for an effective incentive programme. Landowners showed a preference towards tangible incentives, in particular management assistance, financial compensation and law enforcement. They indicated an aversion to an incentive programme implemented by a government agency, particularly district and provincial government. Rather, landowners showed a propensity towards a nongovernment organisation (NGO) or a farmers group implementing an incentive programme. It was recommended that the two major pressures, namely land transformation and alien invader plants, required different interventions by different agencies in order to be mitigated. The pressure of land transformation required a stewardship model response, with the primary drive being a non-contractual environmental extension service to landowners. The extension service should focus on promoting pro-conservation practises, raising awareness and disseminating information. It should also build a relationship of trust between landowners and the implementing agency. The pressure of alien invader plants would be most effectively addressed through the Working for Water programme. Tangible incentives must be provided to the landowner to induce the costly exercise of alien invader plant control. In particular, the high cost of labour must be addressed. The regulatory incentive of applying laws requiring landowners to control alien invader plants on their land should also be enforced.
- Full Text:
- Date Issued: 2007
- Authors: Cumming, Tracey Lyn
- Date: 2007
- Subjects: Landowners -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4745 , http://hdl.handle.net/10962/d1006953 , Landowners -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape
- Description: This study sought opportunities to mitigate the pressures of land transformation and alien invader plants on commercial farm land in the thicket biome in the lower reaches of the Fish Kowie Corridor. It had two aims. Firstly, to determine the role incentives could play in mitigating these pressures. Secondly, to determine the characteristics of an incentive programme that would most effectively achieve this. In order to do this, an understanding of landowner activities, needs, opinions and barriers to behaviour; the nature of the pressures on thicket and the nature of the required behaviour to reduce these pressures; and current and past institutional arrangements needed to be achieved. This was done predominantly through a current literature review and personal interviews with landowners and key informants. These findings were used to make recommendations for an effective incentive programme. Landowners showed a preference towards tangible incentives, in particular management assistance, financial compensation and law enforcement. They indicated an aversion to an incentive programme implemented by a government agency, particularly district and provincial government. Rather, landowners showed a propensity towards a nongovernment organisation (NGO) or a farmers group implementing an incentive programme. It was recommended that the two major pressures, namely land transformation and alien invader plants, required different interventions by different agencies in order to be mitigated. The pressure of land transformation required a stewardship model response, with the primary drive being a non-contractual environmental extension service to landowners. The extension service should focus on promoting pro-conservation practises, raising awareness and disseminating information. It should also build a relationship of trust between landowners and the implementing agency. The pressure of alien invader plants would be most effectively addressed through the Working for Water programme. Tangible incentives must be provided to the landowner to induce the costly exercise of alien invader plant control. In particular, the high cost of labour must be addressed. The regulatory incentive of applying laws requiring landowners to control alien invader plants on their land should also be enforced.
- Full Text:
- Date Issued: 2007
The conservation status of some unique plant communities in the Eastern Cape
- Authors: Everard, David Alexander
- Date: 1986 , 2013-03-14
- Subjects: Plant conservation -- South Africa -- Eastern Cape , Endangered species -- South Africa , Plant conservation -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4250 , http://hdl.handle.net/10962/d1007497 , Plant conservation -- South Africa -- Eastern Cape , Endangered species -- South Africa , Plant conservation -- South Africa -- Western Cape
- Description: In response to a growing concern over the rising rates of extinction of the world's plants and of habitat destruction, studies of Southern African threatened plants were initiated in the 1970's. These studies, which have largely concentrated on Western Cape flora, led to the publication of "Threatened Plants of Southern Africa" by Hall et al., 1980, which attempted to list as many threatened or possibly threatened species as possible. It was however marred by a lack of recent herbarium records and detailed studies from many parts of the region, the Eastern Cape being one of these. In order to extend these detailed studies to gain a clearer picture of the numbers of threatened species in the Eastern Cape and evaluate the conservation status of Eastern Cape vegetation this project was initiated. Initially lists of possibly threatened and endemic taxa of the Eastern Cape were compiled from various sources. These listed taxa were then checked against herbarium records, all available information being filled onto index cards for filing purposes. This paper-based filing system was then transferred into a computer-based data bank to facilitate the efficient storage and retrieval of information. Results from this data bank show that there are 662 variously threatened plant taxa in the Eastern Cape, many of which fall into temporary categories which need to be clarified by investigation in the field. Primarily based on the above results, a table ranking the various vegetation types into an order of priority for investigations about conservation requirement was developed.Subtropical Thicket was found to be the vegetation type in most need of investigation and so an extensive phytosociological survey was carried out in the Valley Bushveld which forms the major portion of Subtropical Thicket in the Eastern Cape. Twelve sites were sampled for floristic and environmental variables along a rainfall gradient of between 300 mm yr⁻¹ and 1 000 mm yr⁻¹ and along a longitudinal gradient from the Buffalo River in the east to the Gamtoos-Kromme complex in the west. Floristic data W(re analysed using multivariate techniques of classification and ordination. A classification by two-way species indicator analysis revealed the Valley Bushveld to consist of two orders of thicket, the Kaffrarian Succulent Thicket containing the two suborders, Inland Succulent Thicket and the Coastal Succulent Thicket and the Kaffrarian Thicket containing Coastal Kaffrarian Thicket and Inland Kaffrarian Thicket. Ordina tion by detrended correspondence analysis also grouped sites according to these vegetation categories in a sequence along one axis, to which the rainfall gradient could be related. Variables such as diversity indices, numbers of endemics, numbers of threatened taxa and structural features were also extracted from the data and these were correlated with environmental variables by multiple regression analysis. Species richness and the percent woody component w\!re positively correlated with rainfall while endemism and percent succulent component were strongly negatively correlated with rainfall. Most of the other relationships were explained by interrelationships with rainfall. Finally the sites were evaluated according to floristic criteria indicative of conservation value. The Coastal Succulent Thicket appeared to have the highest conservation value mainly owing to high endemism, while Inland Kaffrarian Thicket was also important as it supports a high number of species. The thickets with high conservation value are therefore the thickets of coastal areas in the western parts of the Eastern Cape which receive a low rainfall and the thickets which receive a rainfall in excess of 800 mm. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1986
- Authors: Everard, David Alexander
- Date: 1986 , 2013-03-14
- Subjects: Plant conservation -- South Africa -- Eastern Cape , Endangered species -- South Africa , Plant conservation -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4250 , http://hdl.handle.net/10962/d1007497 , Plant conservation -- South Africa -- Eastern Cape , Endangered species -- South Africa , Plant conservation -- South Africa -- Western Cape
- Description: In response to a growing concern over the rising rates of extinction of the world's plants and of habitat destruction, studies of Southern African threatened plants were initiated in the 1970's. These studies, which have largely concentrated on Western Cape flora, led to the publication of "Threatened Plants of Southern Africa" by Hall et al., 1980, which attempted to list as many threatened or possibly threatened species as possible. It was however marred by a lack of recent herbarium records and detailed studies from many parts of the region, the Eastern Cape being one of these. In order to extend these detailed studies to gain a clearer picture of the numbers of threatened species in the Eastern Cape and evaluate the conservation status of Eastern Cape vegetation this project was initiated. Initially lists of possibly threatened and endemic taxa of the Eastern Cape were compiled from various sources. These listed taxa were then checked against herbarium records, all available information being filled onto index cards for filing purposes. This paper-based filing system was then transferred into a computer-based data bank to facilitate the efficient storage and retrieval of information. Results from this data bank show that there are 662 variously threatened plant taxa in the Eastern Cape, many of which fall into temporary categories which need to be clarified by investigation in the field. Primarily based on the above results, a table ranking the various vegetation types into an order of priority for investigations about conservation requirement was developed.Subtropical Thicket was found to be the vegetation type in most need of investigation and so an extensive phytosociological survey was carried out in the Valley Bushveld which forms the major portion of Subtropical Thicket in the Eastern Cape. Twelve sites were sampled for floristic and environmental variables along a rainfall gradient of between 300 mm yr⁻¹ and 1 000 mm yr⁻¹ and along a longitudinal gradient from the Buffalo River in the east to the Gamtoos-Kromme complex in the west. Floristic data W(re analysed using multivariate techniques of classification and ordination. A classification by two-way species indicator analysis revealed the Valley Bushveld to consist of two orders of thicket, the Kaffrarian Succulent Thicket containing the two suborders, Inland Succulent Thicket and the Coastal Succulent Thicket and the Kaffrarian Thicket containing Coastal Kaffrarian Thicket and Inland Kaffrarian Thicket. Ordina tion by detrended correspondence analysis also grouped sites according to these vegetation categories in a sequence along one axis, to which the rainfall gradient could be related. Variables such as diversity indices, numbers of endemics, numbers of threatened taxa and structural features were also extracted from the data and these were correlated with environmental variables by multiple regression analysis. Species richness and the percent woody component w\!re positively correlated with rainfall while endemism and percent succulent component were strongly negatively correlated with rainfall. Most of the other relationships were explained by interrelationships with rainfall. Finally the sites were evaluated according to floristic criteria indicative of conservation value. The Coastal Succulent Thicket appeared to have the highest conservation value mainly owing to high endemism, while Inland Kaffrarian Thicket was also important as it supports a high number of species. The thickets with high conservation value are therefore the thickets of coastal areas in the western parts of the Eastern Cape which receive a low rainfall and the thickets which receive a rainfall in excess of 800 mm. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1986
Population assessments of priority plant species used by local communities in and around three Wild Coast reserves, Eastern Cape, South Africa
- Authors: Fearon, Joclyn Joe
- Date: 2011
- Subjects: Plant diversity conservation -- South Africa -- Eastern Cape , Rare plants -- South Africa -- Eastern Cape -- Population viability analysis , Biodiversity -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape , Human-plant relationships -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4751 , http://hdl.handle.net/10962/d1007059 , Plant diversity conservation -- South Africa -- Eastern Cape , Rare plants -- South Africa -- Eastern Cape -- Population viability analysis , Biodiversity -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape , Human-plant relationships -- South Africa -- Eastern Cape
- Description: The project was initiated by Eastern Cape Parks (ECP) as a request for the construction of inventories of priority species and their population levels inside three nature reserves on the Eastern Cape Wild Coast, South Africa, and to develop a strategic management plan to manage these natural resources in each reserve. Thirty key species were identified by local communities in and around Dwesa-Cwebe, Silaka and Mkambati Nature Reserves through community workshops. For forested areas belt transects of 100 m x 6 m where used. The basal circumference of key tree species within the belt transect was measured as well as the height of saplings (height < 150 m). Tree species were categorized based on densities, size class distribution (SCD) curves and values, and spatial grain. For grassland areas straight transects of 200 m long were used, along which ten 3 m x 3 m quadrates were placed at 20 m intervals. Within each grassland transect the height of herbs or tuft diameter of grasses was recorded and percentage cover estimated. Grassland species were categorized based on density, SCD curves and percentage cover. All species were placed into harvesting categories based on analysed ecological data that was collected in the field. Category 1 species were very rare or not found in the reserve and it was recommended that species be conserved and monitored. Category 2 species had low densities in the reserve indicating declining populations and was suggested that these be monitored and not harvested. Category 3 species had high densities and have potential for harvesting with strict limitations. Category 4 species were most abundant with very high densities and can be harvested within management guidelines. These categories were grouped further using social and ecological data such as harvesting risk, frequency of collection, use value and number of uses. This highlighted which species have conservation priority within each category and a decision can be made as to how intense or limited extraction should be. By incorporating GIS the distribution of each species was looked at and harvesting and non-harvesting zones established to determine where species can be extracted. Monitoring plans must consider the quantity of plant material collected, fire regimes, optimal harvesting rates and harvesting zones, and be able to pick up changes in populations. Also, it is important that the community be involved in conserving and monitoring these species. Adaptive monitoring and management must be used to steer harvesting practices in the Wild Coast reserves. This allows for the development of harvesting practices through ‘learning by doing’, and the evolution of good questions to guide monitoring decisions
- Full Text:
- Date Issued: 2011
- Authors: Fearon, Joclyn Joe
- Date: 2011
- Subjects: Plant diversity conservation -- South Africa -- Eastern Cape , Rare plants -- South Africa -- Eastern Cape -- Population viability analysis , Biodiversity -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape , Human-plant relationships -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4751 , http://hdl.handle.net/10962/d1007059 , Plant diversity conservation -- South Africa -- Eastern Cape , Rare plants -- South Africa -- Eastern Cape -- Population viability analysis , Biodiversity -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape , Human-plant relationships -- South Africa -- Eastern Cape
- Description: The project was initiated by Eastern Cape Parks (ECP) as a request for the construction of inventories of priority species and their population levels inside three nature reserves on the Eastern Cape Wild Coast, South Africa, and to develop a strategic management plan to manage these natural resources in each reserve. Thirty key species were identified by local communities in and around Dwesa-Cwebe, Silaka and Mkambati Nature Reserves through community workshops. For forested areas belt transects of 100 m x 6 m where used. The basal circumference of key tree species within the belt transect was measured as well as the height of saplings (height < 150 m). Tree species were categorized based on densities, size class distribution (SCD) curves and values, and spatial grain. For grassland areas straight transects of 200 m long were used, along which ten 3 m x 3 m quadrates were placed at 20 m intervals. Within each grassland transect the height of herbs or tuft diameter of grasses was recorded and percentage cover estimated. Grassland species were categorized based on density, SCD curves and percentage cover. All species were placed into harvesting categories based on analysed ecological data that was collected in the field. Category 1 species were very rare or not found in the reserve and it was recommended that species be conserved and monitored. Category 2 species had low densities in the reserve indicating declining populations and was suggested that these be monitored and not harvested. Category 3 species had high densities and have potential for harvesting with strict limitations. Category 4 species were most abundant with very high densities and can be harvested within management guidelines. These categories were grouped further using social and ecological data such as harvesting risk, frequency of collection, use value and number of uses. This highlighted which species have conservation priority within each category and a decision can be made as to how intense or limited extraction should be. By incorporating GIS the distribution of each species was looked at and harvesting and non-harvesting zones established to determine where species can be extracted. Monitoring plans must consider the quantity of plant material collected, fire regimes, optimal harvesting rates and harvesting zones, and be able to pick up changes in populations. Also, it is important that the community be involved in conserving and monitoring these species. Adaptive monitoring and management must be used to steer harvesting practices in the Wild Coast reserves. This allows for the development of harvesting practices through ‘learning by doing’, and the evolution of good questions to guide monitoring decisions
- Full Text:
- Date Issued: 2011
The conservation status of subtropical transitional thicket, and regeneration through seeding of shrubs in the Xeric succulent thicket of the Eastern Cape
- Authors: La Cock, Graeme Dennis
- Date: 1992
- Subjects: Plant conservation -- South Africa -- Eastern Cape , Woody plants -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4208 , http://hdl.handle.net/10962/d1003777 , Plant conservation -- South Africa -- Eastern Cape , Woody plants -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Western Cape
- Description: The historically poorly conserved subtropical transitional thicket (STT) of the Eastern Cape is overutilised by domestic stock and game in the more xeric areas, and has shown no signs of recovery from this grazing pressure. It has been postulated that no regeneration through seeding occurs. This project was undertaken to determine: 1) how much STT has disappeared between 1950 and present, and what the current conservation status is; and 2) whether regeneration of the xeric succulent thicket is taking place through seeding, and if so, where. The study was conducted at the Andries Vosloo Kudu Reserve near Grahamstown. Approximately one-third less STT was mapped in this study, based on 1981 Landsat images, than was mapped in 1950. Approximately 10 % of all remaining STT is conserved. The order Kaffrarian thicket is poorly conserved. Newly germinated seedlings of a wide range of shrub species occurred under the canopies of a wide range of shrubs which served as nurse plants, throughout a gradient of veld condition. Seedlings of Portulacaria afra, the dominant shrub in xeric succulent thicket, were most common. Similarly all saplings recorded in a survey of saplings were associated with bushclumps. One-third of all saplings have the potential to contribute to the spread of bushclumps. Regeneration of xeric succulent thicket through seeding probably does occur, contrary to current ideas. Ptareoxylon obliquum was the most common sapling, despite mature trees now being scarce following earlier heavier utilisation . P. obliquum was also the nurse plant which supported the highest density of newly germinated seedlings. The possible role of P. obliquum in the functioning of xeric succulent thicket is discussed. The confinement of seedlings and saplings to areas under the canopies of trees and shrubs implies that the xeric succulent thicket will not recover rapidly if allowed to rest. Active management techniques will be necessary if rapid recovery is required. Bare areas between bushclumps may no longer be suitable germination habitats because of high Al concentrations. There was no evidence to support the idea that germination and establishment of shrubs in clear areas is linked to episodic climatic events. Dung middens of recently reintroduced black rhinoceros may however aid in germination of seeds and establishment of seedlings under certain climatic conditions. Recommendations for further studies, based on the findings of this project, are made. Possible management techniques aimed at the rapid recovery of this veld are suggested, and management proposals for the Sam Knott Nature Reserve/Andries Vosloo Kudu Reserve complex are made.
- Full Text:
- Date Issued: 1992
- Authors: La Cock, Graeme Dennis
- Date: 1992
- Subjects: Plant conservation -- South Africa -- Eastern Cape , Woody plants -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4208 , http://hdl.handle.net/10962/d1003777 , Plant conservation -- South Africa -- Eastern Cape , Woody plants -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Western Cape
- Description: The historically poorly conserved subtropical transitional thicket (STT) of the Eastern Cape is overutilised by domestic stock and game in the more xeric areas, and has shown no signs of recovery from this grazing pressure. It has been postulated that no regeneration through seeding occurs. This project was undertaken to determine: 1) how much STT has disappeared between 1950 and present, and what the current conservation status is; and 2) whether regeneration of the xeric succulent thicket is taking place through seeding, and if so, where. The study was conducted at the Andries Vosloo Kudu Reserve near Grahamstown. Approximately one-third less STT was mapped in this study, based on 1981 Landsat images, than was mapped in 1950. Approximately 10 % of all remaining STT is conserved. The order Kaffrarian thicket is poorly conserved. Newly germinated seedlings of a wide range of shrub species occurred under the canopies of a wide range of shrubs which served as nurse plants, throughout a gradient of veld condition. Seedlings of Portulacaria afra, the dominant shrub in xeric succulent thicket, were most common. Similarly all saplings recorded in a survey of saplings were associated with bushclumps. One-third of all saplings have the potential to contribute to the spread of bushclumps. Regeneration of xeric succulent thicket through seeding probably does occur, contrary to current ideas. Ptareoxylon obliquum was the most common sapling, despite mature trees now being scarce following earlier heavier utilisation . P. obliquum was also the nurse plant which supported the highest density of newly germinated seedlings. The possible role of P. obliquum in the functioning of xeric succulent thicket is discussed. The confinement of seedlings and saplings to areas under the canopies of trees and shrubs implies that the xeric succulent thicket will not recover rapidly if allowed to rest. Active management techniques will be necessary if rapid recovery is required. Bare areas between bushclumps may no longer be suitable germination habitats because of high Al concentrations. There was no evidence to support the idea that germination and establishment of shrubs in clear areas is linked to episodic climatic events. Dung middens of recently reintroduced black rhinoceros may however aid in germination of seeds and establishment of seedlings under certain climatic conditions. Recommendations for further studies, based on the findings of this project, are made. Possible management techniques aimed at the rapid recovery of this veld are suggested, and management proposals for the Sam Knott Nature Reserve/Andries Vosloo Kudu Reserve complex are made.
- Full Text:
- Date Issued: 1992
Restoration of degraded subtropical thickets in the Baviaanskloof Megareserve, South Africa: the role of carbon stocks and Portulacaria afra survivorship
- Authors: Powell, Michael John
- Date: 2009
- Subjects: Portulacaria afra -- South Africa -- Eastern Cape , Portulacaceae -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Baviaanskloof (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4764 , http://hdl.handle.net/10962/d1007164 , Portulacaria afra -- South Africa -- Eastern Cape , Portulacaceae -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Baviaanskloof (South Africa)
- Description: The semi-arid forms of subtropical thicket in the Eastern and Western Cape have been heavily degraded through unsustainable pastoralism over the last century or more. The degraded areas exhibit a significant loss of above-ground and belowground carbon stocks, and consequently provide an opportunity for restoration through the formal and informal carbon markets. A prerequisite for the attainment of carbon credits is to ensure sound carbon stock baselines prior to effecting restoration. I report on the carbon stocks (including sub-pools) for a number of intact subtropical thicket types, as well as the differentials between the intact and degraded states (including the sub-pools). Total carbon stocks (TCS in t C ha⁻¹) for intact vegetation (to a soil depth 0–25 cm), ranged from 87.73±6.51 to 70.64±17.24. For degraded vegetation (including old lands), TCS (t C ha⁻¹) ranged from 34.05±3.61 to 21.03±2.70. For all vegetation types, the differentials in TCS along the degradation gradient (0–25 cm) are highly significant and strengthen the possibility for carbon credit financing to catalyse the restoration of the degraded semi-arid subtropical thickets. This study has shown a mean loss of 57.23 t C ha⁻¹ in Baviaanskloof spekboom thickets, when measured to a soil depth of 25 cm. Portulacaria afra is a key species within the semi-arid subtropical thickets, being a canopy dominant and a driver of soil nutrient status, but has been largely lost from the degraded landscapes. Degraded semi-arid subtropical thicket vegetation lacks regeneration via seedling recruitment; restoration therefore requires the manual replanting of P. afra using cut truncheons. Survivorship trials were undertaken infield in 2005 to establish restoration protocols for P. afra, with survivorship being recorded in 2006 and 2008. Overall survivorship for all treatments was found to be 43.2±2.8% in 2006, dropping to 35.8±2.7% in 2008. Planting posture (flat or upright) showed the most significant results of all the factors tested in 2006 and 2008. Micro-damming also influenced survivorship in that micro-damming was associated with marginally higher survivorship (47.4 ±2.0% with damming vs. 39.1±1.5% without damming in 2006, and 39.3±1.9% vs. 32.3±1.5% in 2008). Higher planting density only showed a significant positive impact on survivorship in 2008. Neither stem diameter nor clumping significantly affected degree of survival. A key finding in the study has been the non-static nature of P. afra truncheon survivorship, even after being well established (three years since planting). The results from the study will guide the restoration protocols for the restoration of degraded subtropical thickets, where P. afra requires replanting.
- Full Text:
- Date Issued: 2009
- Authors: Powell, Michael John
- Date: 2009
- Subjects: Portulacaria afra -- South Africa -- Eastern Cape , Portulacaceae -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Baviaanskloof (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4764 , http://hdl.handle.net/10962/d1007164 , Portulacaria afra -- South Africa -- Eastern Cape , Portulacaceae -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Baviaanskloof (South Africa)
- Description: The semi-arid forms of subtropical thicket in the Eastern and Western Cape have been heavily degraded through unsustainable pastoralism over the last century or more. The degraded areas exhibit a significant loss of above-ground and belowground carbon stocks, and consequently provide an opportunity for restoration through the formal and informal carbon markets. A prerequisite for the attainment of carbon credits is to ensure sound carbon stock baselines prior to effecting restoration. I report on the carbon stocks (including sub-pools) for a number of intact subtropical thicket types, as well as the differentials between the intact and degraded states (including the sub-pools). Total carbon stocks (TCS in t C ha⁻¹) for intact vegetation (to a soil depth 0–25 cm), ranged from 87.73±6.51 to 70.64±17.24. For degraded vegetation (including old lands), TCS (t C ha⁻¹) ranged from 34.05±3.61 to 21.03±2.70. For all vegetation types, the differentials in TCS along the degradation gradient (0–25 cm) are highly significant and strengthen the possibility for carbon credit financing to catalyse the restoration of the degraded semi-arid subtropical thickets. This study has shown a mean loss of 57.23 t C ha⁻¹ in Baviaanskloof spekboom thickets, when measured to a soil depth of 25 cm. Portulacaria afra is a key species within the semi-arid subtropical thickets, being a canopy dominant and a driver of soil nutrient status, but has been largely lost from the degraded landscapes. Degraded semi-arid subtropical thicket vegetation lacks regeneration via seedling recruitment; restoration therefore requires the manual replanting of P. afra using cut truncheons. Survivorship trials were undertaken infield in 2005 to establish restoration protocols for P. afra, with survivorship being recorded in 2006 and 2008. Overall survivorship for all treatments was found to be 43.2±2.8% in 2006, dropping to 35.8±2.7% in 2008. Planting posture (flat or upright) showed the most significant results of all the factors tested in 2006 and 2008. Micro-damming also influenced survivorship in that micro-damming was associated with marginally higher survivorship (47.4 ±2.0% with damming vs. 39.1±1.5% without damming in 2006, and 39.3±1.9% vs. 32.3±1.5% in 2008). Higher planting density only showed a significant positive impact on survivorship in 2008. Neither stem diameter nor clumping significantly affected degree of survival. A key finding in the study has been the non-static nature of P. afra truncheon survivorship, even after being well established (three years since planting). The results from the study will guide the restoration protocols for the restoration of degraded subtropical thickets, where P. afra requires replanting.
- Full Text:
- Date Issued: 2009
Life history, population dynamics and conservation status of Oldenburgia grandis (Asteraceae), an endemic of the Eastern Cape of South Africa
- Authors: Swart, Carin
- Date: 2008
- Subjects: Compositae , Fynbos ecology -- South Africa -- Eastern Cape , Endemic plants -- South Africa -- Eastern Cape , Rare plants -- South Africa -- Eastern Cape , Plant populations -- South Africa -- Eastern Cape , Vegetation dynamics -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Endangered species -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4230 , http://hdl.handle.net/10962/d1003799 , Compositae , Fynbos ecology -- South Africa -- Eastern Cape , Endemic plants -- South Africa -- Eastern Cape , Rare plants -- South Africa -- Eastern Cape , Plant populations -- South Africa -- Eastern Cape , Vegetation dynamics -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Endangered species -- South Africa -- Eastern Cape
- Description: Oldenburgia grandis is a rare, long-lived woody paleoendemic of the Fynbos Biome of South Africa. Confined to quartzite outcrops, it has a small geographic range and narrow habitat specificity. O. grandis responds to its fire-prone environment by resprouting. Elasticity analysis of O. grandis reveals that growth and fecundity were traded off for persistence of adult, mature and sapling stages. Morphological adaptations such as a corky fire-resistant bark and the ability to resprout after fire are traits that O. grandis have evolved to persist in a frequently disturbed environment. Population growth rate for sites undisturbed by fire for a number of years (l = 1.01) and sites at various stages of recovery after fire (l = 1.00) were very similar. The highest variation in transition probabilities for all sites was seen in the persistence of the seedling stage and growth from seedling to sapling. Observed population structure and stable stage distribution determined by the matrix model show that sites recently undisturbed by fire had high abundances of the adult and sapling stages. A peak in sapling stages was seen for the stable stage distribution where similar peak in sapling numbers were seen for population structures of sites at various stages of recoveryafter fire. Favourable environmental conditions for the persistence of O. grandis populations include no fire with transition probabilities between the observed minimum and maximum and fire frequency at a 10 year interval where seedling protection from the fire is high and adult and mature mortalities during the fire are low. Stochastic environmental events that could put populations (particularly small populations) at an increased risk of extinction include high to moderate fire intensities where seedling protection from the fire is low and adult and mature mortalities are high as a result of the fire.
- Full Text:
- Date Issued: 2008
- Authors: Swart, Carin
- Date: 2008
- Subjects: Compositae , Fynbos ecology -- South Africa -- Eastern Cape , Endemic plants -- South Africa -- Eastern Cape , Rare plants -- South Africa -- Eastern Cape , Plant populations -- South Africa -- Eastern Cape , Vegetation dynamics -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Endangered species -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4230 , http://hdl.handle.net/10962/d1003799 , Compositae , Fynbos ecology -- South Africa -- Eastern Cape , Endemic plants -- South Africa -- Eastern Cape , Rare plants -- South Africa -- Eastern Cape , Plant populations -- South Africa -- Eastern Cape , Vegetation dynamics -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Endangered species -- South Africa -- Eastern Cape
- Description: Oldenburgia grandis is a rare, long-lived woody paleoendemic of the Fynbos Biome of South Africa. Confined to quartzite outcrops, it has a small geographic range and narrow habitat specificity. O. grandis responds to its fire-prone environment by resprouting. Elasticity analysis of O. grandis reveals that growth and fecundity were traded off for persistence of adult, mature and sapling stages. Morphological adaptations such as a corky fire-resistant bark and the ability to resprout after fire are traits that O. grandis have evolved to persist in a frequently disturbed environment. Population growth rate for sites undisturbed by fire for a number of years (l = 1.01) and sites at various stages of recovery after fire (l = 1.00) were very similar. The highest variation in transition probabilities for all sites was seen in the persistence of the seedling stage and growth from seedling to sapling. Observed population structure and stable stage distribution determined by the matrix model show that sites recently undisturbed by fire had high abundances of the adult and sapling stages. A peak in sapling stages was seen for the stable stage distribution where similar peak in sapling numbers were seen for population structures of sites at various stages of recoveryafter fire. Favourable environmental conditions for the persistence of O. grandis populations include no fire with transition probabilities between the observed minimum and maximum and fire frequency at a 10 year interval where seedling protection from the fire is high and adult and mature mortalities during the fire are low. Stochastic environmental events that could put populations (particularly small populations) at an increased risk of extinction include high to moderate fire intensities where seedling protection from the fire is low and adult and mature mortalities are high as a result of the fire.
- Full Text:
- Date Issued: 2008
- «
- ‹
- 1
- ›
- »