Acacia dealbata invasion and clearing in Upper Tsitsana communal areas of South Africa: human perceptions and ecological impacts
- Authors: Coka, Nwabisa
- Date: 2024-04-04
- Subjects: Restoration ecology South Africa Eastern Cape , Acacia dealbata , Invasive plants South Africa Eastern Cape , Working for Water Programme , Invasive plants Control South Africa Eastern Cape
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/434876 , vital:73113
- Description: The number of invasive alien plants in South Africa and globally continue to increase mostly due to increased human movement and climate change. It is estimated that approximately 10 000 hectares of South Africa’s terrestrial land is invaded by invasive alien species. Recent studies have reported that invasion by invasive alien plants cost South Africa billions of Rands every year through loss of water and ecosystem services. Although much has been done to understanding invasion trends, patterns, and processes in South Africa, little is knowns regarding human benefits linked to alien plant invasion as well as human perceptions regarding management interventions, particularly clearing by the national Working for Water programme. This thesis took a socio-ecological approach to assess (i) local people perceptions and knowledge of Acacia dealbata invasion and clearing, and (ii) extent of grazing grass diversity and composition recovery following A. dealbata clearing. To answer the above-mentioned objectives, both qualitative (face-to-face interviews) and quantitative (vegetation surveys) methods were used in grasslands located in upper Tsitsana catchment, South Africa. Results from the 165 interviews conducted in six villages show that most villagers are aware of A. dealbata in the area, but do not know that it is an invasive alien plant. Respondents accrue several benefits from the plant that include firewood (98% across all villages), construction pools (34% across all villages), and shade (3% across all villages). Respondents identified several costs associated with A. dealbata invasion, such as roots damage to houses (37% across all villages), hindering growth of crops (15% across all villages), and takes up yard space (29% across all villages). Most of the villages ranked the effects of A. dealbata on grazing as highly severe. Villages indicated that the Working for Water clearing programme presents them with socio-economic benefits such as employment and money. Some villagers noted that the clearing of A. dealbata in the area restores grazing grass (62% across all villages) and water (32% across all villages). Based on these interview survey results, the study concludes that A. dealbata has both costs and benefits that support local people’s livelihoods; therefore, its management should consider views for local users. Grass surveys conducted in 1 m2 quadrats that were replicated 15 times across four paired A. dealbata cleared and grassland sites showed that the removal of A. dealbata facilitates the recovery of native grasses. Of the 14 different grazable grass species that were identified across all quadrats only one (Bulbostylis sp.) is not palatable to livestock. Although grass cover was significantly (p < 0.05) higher in the grasslands than the cleared patches, grass richness was significantly (p < 0.05) higher in the cleared patches an indication that recovery of different grasses is taking place. Based on these vegetation survey results; the study concludes that recovery of grazing grasses after A. dealbata clearing four years ago is following a positive trajectory as the cleared sites are looking like the grassland sites. Overall, the study recommends that management of A. dealbata in Tsitsana landscape requires a socio-ecological approach to understand user benefits whilst at the same time developing measure to control the plant. The study has provided evidence that A. dealbata clearing facilitates passive restoration of grazing grass and local villages are aware of these restoration benefits. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Coka, Nwabisa
- Date: 2024-04-04
- Subjects: Restoration ecology South Africa Eastern Cape , Acacia dealbata , Invasive plants South Africa Eastern Cape , Working for Water Programme , Invasive plants Control South Africa Eastern Cape
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/434876 , vital:73113
- Description: The number of invasive alien plants in South Africa and globally continue to increase mostly due to increased human movement and climate change. It is estimated that approximately 10 000 hectares of South Africa’s terrestrial land is invaded by invasive alien species. Recent studies have reported that invasion by invasive alien plants cost South Africa billions of Rands every year through loss of water and ecosystem services. Although much has been done to understanding invasion trends, patterns, and processes in South Africa, little is knowns regarding human benefits linked to alien plant invasion as well as human perceptions regarding management interventions, particularly clearing by the national Working for Water programme. This thesis took a socio-ecological approach to assess (i) local people perceptions and knowledge of Acacia dealbata invasion and clearing, and (ii) extent of grazing grass diversity and composition recovery following A. dealbata clearing. To answer the above-mentioned objectives, both qualitative (face-to-face interviews) and quantitative (vegetation surveys) methods were used in grasslands located in upper Tsitsana catchment, South Africa. Results from the 165 interviews conducted in six villages show that most villagers are aware of A. dealbata in the area, but do not know that it is an invasive alien plant. Respondents accrue several benefits from the plant that include firewood (98% across all villages), construction pools (34% across all villages), and shade (3% across all villages). Respondents identified several costs associated with A. dealbata invasion, such as roots damage to houses (37% across all villages), hindering growth of crops (15% across all villages), and takes up yard space (29% across all villages). Most of the villages ranked the effects of A. dealbata on grazing as highly severe. Villages indicated that the Working for Water clearing programme presents them with socio-economic benefits such as employment and money. Some villagers noted that the clearing of A. dealbata in the area restores grazing grass (62% across all villages) and water (32% across all villages). Based on these interview survey results, the study concludes that A. dealbata has both costs and benefits that support local people’s livelihoods; therefore, its management should consider views for local users. Grass surveys conducted in 1 m2 quadrats that were replicated 15 times across four paired A. dealbata cleared and grassland sites showed that the removal of A. dealbata facilitates the recovery of native grasses. Of the 14 different grazable grass species that were identified across all quadrats only one (Bulbostylis sp.) is not palatable to livestock. Although grass cover was significantly (p < 0.05) higher in the grasslands than the cleared patches, grass richness was significantly (p < 0.05) higher in the cleared patches an indication that recovery of different grasses is taking place. Based on these vegetation survey results; the study concludes that recovery of grazing grasses after A. dealbata clearing four years ago is following a positive trajectory as the cleared sites are looking like the grassland sites. Overall, the study recommends that management of A. dealbata in Tsitsana landscape requires a socio-ecological approach to understand user benefits whilst at the same time developing measure to control the plant. The study has provided evidence that A. dealbata clearing facilitates passive restoration of grazing grass and local villages are aware of these restoration benefits. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-04-04
Drought impacts on livestock and crop production along an urban-rural gradient: perceptions and response strategies in the Eastern Cape province, South Africa
- Authors: Pamla, Avela
- Date: 2023-10-13
- Subjects: Livestock Effect of drought on South Africa Eastern Cape , Farms, Small South Africa Eastern Cape , Crops and climate South Africa Eastern Cape , Drought management South Africa Eastern Cape
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424732 , vital:72179
- Description: Drought is a major challenge threatening agricultural productivity in urban and rural areas across southern Africa. Drought events are expected to be more frequent, severe, last longer, and, impact land-based livelihoods in the coming decades. Despite the growing literature on the impacts of drought on livelihoods, there is limited focus on the impacts of droughts across rural-urban gradients. The study examined small-scale farmers’ perceptions of drought impacts and response strategies in the contexts of persistent droughts in the Eastern Cape province of South Africa. A total of 163 respondents, practicing livestock and/or crop farming across six towns, in urban and rural contexts were purposively identified. The study used snowball sampling approach to identify the relevant respondents. Data were collected through a semi-structured questionnaire survey, exploring the respondents' socio-demographic profiles, agricultural activities, perceptions of drought impacts, and drought response strategies. Qualitative data were coded and analyzed using descriptive statistics, thematic analysis, t-tests, and chi-square tests to identify patterns, themes, and relationships within the data. Nearly all (>95%) respondents owned livestock while substantially more rural farmers (81%) than urban farmers (35%) engaged in crop production. Drought was perceived by a sizeable proportion (>70%) of small-scale farmers as a very serious environmental challenge with adverse socio-economic repercussions on land-based activities. Livestock losses and crop failure were the key impacts reported by small-scale farmers in both rural and urban settings. About 86% of respondents across the sample reported declines in crop yields, with significantly more farmers in rural sites (45%) than urban sites (31%) reporting so. A substantial proportion of farmers across the sample (93%) reported drought response strategies relating to livestock and crop production, such as changing of farming practices, use of drought-resistant crops and government support, with slight differences in the proportion of farmers reporting so between urban (89 %) and rural (95 %) sites. Concerning government support, most respondents (>70%) stated that they were dissatisfied, with slightly more respondents in urban areas (77%) than in rural (70%) areas reporting so. Overall, the results of this study suggest a minimal response capacity of small-scale farmers to droughts in both rural and urban settings due to socio-economic and administrative factors, which calls for the need for drought-response strategies to build adaptive capacity for small-scale farmers. Turning to close cooperation between different stakeholders, such as local farmers, government officials, practitioners, and scientists might allow co-production of knowledge needed to inform drought response strategies. In some instances, attention needs to be given to farmers who are more vulnerable than others. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Pamla, Avela
- Date: 2023-10-13
- Subjects: Livestock Effect of drought on South Africa Eastern Cape , Farms, Small South Africa Eastern Cape , Crops and climate South Africa Eastern Cape , Drought management South Africa Eastern Cape
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424732 , vital:72179
- Description: Drought is a major challenge threatening agricultural productivity in urban and rural areas across southern Africa. Drought events are expected to be more frequent, severe, last longer, and, impact land-based livelihoods in the coming decades. Despite the growing literature on the impacts of drought on livelihoods, there is limited focus on the impacts of droughts across rural-urban gradients. The study examined small-scale farmers’ perceptions of drought impacts and response strategies in the contexts of persistent droughts in the Eastern Cape province of South Africa. A total of 163 respondents, practicing livestock and/or crop farming across six towns, in urban and rural contexts were purposively identified. The study used snowball sampling approach to identify the relevant respondents. Data were collected through a semi-structured questionnaire survey, exploring the respondents' socio-demographic profiles, agricultural activities, perceptions of drought impacts, and drought response strategies. Qualitative data were coded and analyzed using descriptive statistics, thematic analysis, t-tests, and chi-square tests to identify patterns, themes, and relationships within the data. Nearly all (>95%) respondents owned livestock while substantially more rural farmers (81%) than urban farmers (35%) engaged in crop production. Drought was perceived by a sizeable proportion (>70%) of small-scale farmers as a very serious environmental challenge with adverse socio-economic repercussions on land-based activities. Livestock losses and crop failure were the key impacts reported by small-scale farmers in both rural and urban settings. About 86% of respondents across the sample reported declines in crop yields, with significantly more farmers in rural sites (45%) than urban sites (31%) reporting so. A substantial proportion of farmers across the sample (93%) reported drought response strategies relating to livestock and crop production, such as changing of farming practices, use of drought-resistant crops and government support, with slight differences in the proportion of farmers reporting so between urban (89 %) and rural (95 %) sites. Concerning government support, most respondents (>70%) stated that they were dissatisfied, with slightly more respondents in urban areas (77%) than in rural (70%) areas reporting so. Overall, the results of this study suggest a minimal response capacity of small-scale farmers to droughts in both rural and urban settings due to socio-economic and administrative factors, which calls for the need for drought-response strategies to build adaptive capacity for small-scale farmers. Turning to close cooperation between different stakeholders, such as local farmers, government officials, practitioners, and scientists might allow co-production of knowledge needed to inform drought response strategies. In some instances, attention needs to be given to farmers who are more vulnerable than others. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-10-13
The distribution and perceptions of invasive alien plants in small towns in the Eastern Cape province, South Africa
- Authors: Seboko, Tshepiso Collen
- Date: 2022-10-14
- Subjects: Invasive plants South Africa Eastern Cape , Land use South Africa Eastern Cape , Invasive plants Control South Africa Eastern Cape , Public opinion South Africa Eastern Cape , Urban ecology (Biology) South Africa Eastern Cape
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:65669
- Description: Invasive alien plants (IAP) of different life forms have major effects on biodiversity, ecosystem functioning, economies, and livelihoods worldwide. There is evidence that IAP are rapidly increasing around the world, and the negative impacts associated with them are expected to worsen due to continuing land transformation, climate change, and urbanisation. Yet, information on the distribution, abundance, knowledge, and perceptions of IAP is limited, especially in small towns. Most previous research has largely focused on rural settings and larger cities, thus hindering the effective control and management of IAP in smaller urban settings. It is therefore important to assess the distribution of IAP to provide useful information to guide clearing and mitigation efforts to reduce the impacts and proliferation of IAP in smaller urban settings. Consequently, the aim of the study was to determine the distribution, composition, abundance, and perceptions of woody IAP in small towns in the Eastern Cape province of South Africa and assess how and why they may differ within and between towns. To achieve this aim, a drive by road survey was undertaken across all suburbs and land use types in 12 small towns located in the Eastern Cape province of South Africa. The 12 randomly selected small towns were, Adelaide, Alexandria, Barkley East, Bedford, Burgersdorp, Cathcart, Kirkwood, Middelburg, Paterson, Somerset East, St. Francis Bay and Willowmore. All woody IAP visible from the surveyed roads were counted across all suburbs and land use types within each town. A total of 38 427 woody IAP were enumerated, with 56 species across different land use types and suburbs in all towns. Affluent suburbs accounted for 58% of the IAP enumerated, while the Reconstructed Development Programme (RDP) suburbs accounted for only 5%. In terms of the land use type, most of the IAP were encountered in the residential areas (54%), as compared to, road verges (32%) and public urban green spaces (PUGS) (14%). Of the 12 towns, Middleburg had the highest number of woody IAP, with 5 573 individuals, while Paterson had the lowest number with 947. The most common IAP species across all towns was Melia azedarach with 4 384 individuals, followed by Pinus elliotti (4 051), and Jacaranda mimosifolia (3 640). Spathodea campanulata, Ardisia crenata, and Parkinsonia aculeata had the lowest number of individuals with only two individuals each across all towns. This study also assessed the knowledge, perceptions, and willingness of urban residents to control IAP in their home yards using household surveys. A total of 240 household surveys were administered in the 12 towns. The results showed that more than half of the respondents (59%) had no knowledge of IAP, while 14% had neutral knowledge and only 2% had high knowledge. Forty percent of the respondents agreed that IAP pose a problem to the environment whilst 11% did not think IAP posed a problem to the environment, and 49% stated that they do not know. Most of the respondents (91%) perceived IAP positively, and stated that they benefit from the IAP, with the most mentioned benefit being shade (50%). Almost two-thirds of the respondents (65%) were willing to report on the IAP in their yards to the relevant authorities that deal with the control and management of IAP. Over half (56%) of the respondents were willing to have the IAP removed from their gardens, with the most stated reason for removal was because the IAP caused damage to property (13%). Respondents thought that the local government (35%) or district government (30%) should be responsible for the control and management of IAP. Overall, the study showed that IAP species were most common in residential land use type and affluent suburbs. These findings can assist the relevant authorities that deal with IAP, regarding which plant species, suburbs, and land use types to prioritise regarding awareness and investment for control and management. This will also help explore alternative indigenous species that can be used as replacements that may offer the same benefits derived from IAP by urban residents. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Seboko, Tshepiso Collen
- Date: 2022-10-14
- Subjects: Invasive plants South Africa Eastern Cape , Land use South Africa Eastern Cape , Invasive plants Control South Africa Eastern Cape , Public opinion South Africa Eastern Cape , Urban ecology (Biology) South Africa Eastern Cape
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:65669
- Description: Invasive alien plants (IAP) of different life forms have major effects on biodiversity, ecosystem functioning, economies, and livelihoods worldwide. There is evidence that IAP are rapidly increasing around the world, and the negative impacts associated with them are expected to worsen due to continuing land transformation, climate change, and urbanisation. Yet, information on the distribution, abundance, knowledge, and perceptions of IAP is limited, especially in small towns. Most previous research has largely focused on rural settings and larger cities, thus hindering the effective control and management of IAP in smaller urban settings. It is therefore important to assess the distribution of IAP to provide useful information to guide clearing and mitigation efforts to reduce the impacts and proliferation of IAP in smaller urban settings. Consequently, the aim of the study was to determine the distribution, composition, abundance, and perceptions of woody IAP in small towns in the Eastern Cape province of South Africa and assess how and why they may differ within and between towns. To achieve this aim, a drive by road survey was undertaken across all suburbs and land use types in 12 small towns located in the Eastern Cape province of South Africa. The 12 randomly selected small towns were, Adelaide, Alexandria, Barkley East, Bedford, Burgersdorp, Cathcart, Kirkwood, Middelburg, Paterson, Somerset East, St. Francis Bay and Willowmore. All woody IAP visible from the surveyed roads were counted across all suburbs and land use types within each town. A total of 38 427 woody IAP were enumerated, with 56 species across different land use types and suburbs in all towns. Affluent suburbs accounted for 58% of the IAP enumerated, while the Reconstructed Development Programme (RDP) suburbs accounted for only 5%. In terms of the land use type, most of the IAP were encountered in the residential areas (54%), as compared to, road verges (32%) and public urban green spaces (PUGS) (14%). Of the 12 towns, Middleburg had the highest number of woody IAP, with 5 573 individuals, while Paterson had the lowest number with 947. The most common IAP species across all towns was Melia azedarach with 4 384 individuals, followed by Pinus elliotti (4 051), and Jacaranda mimosifolia (3 640). Spathodea campanulata, Ardisia crenata, and Parkinsonia aculeata had the lowest number of individuals with only two individuals each across all towns. This study also assessed the knowledge, perceptions, and willingness of urban residents to control IAP in their home yards using household surveys. A total of 240 household surveys were administered in the 12 towns. The results showed that more than half of the respondents (59%) had no knowledge of IAP, while 14% had neutral knowledge and only 2% had high knowledge. Forty percent of the respondents agreed that IAP pose a problem to the environment whilst 11% did not think IAP posed a problem to the environment, and 49% stated that they do not know. Most of the respondents (91%) perceived IAP positively, and stated that they benefit from the IAP, with the most mentioned benefit being shade (50%). Almost two-thirds of the respondents (65%) were willing to report on the IAP in their yards to the relevant authorities that deal with the control and management of IAP. Over half (56%) of the respondents were willing to have the IAP removed from their gardens, with the most stated reason for removal was because the IAP caused damage to property (13%). Respondents thought that the local government (35%) or district government (30%) should be responsible for the control and management of IAP. Overall, the study showed that IAP species were most common in residential land use type and affluent suburbs. These findings can assist the relevant authorities that deal with IAP, regarding which plant species, suburbs, and land use types to prioritise regarding awareness and investment for control and management. This will also help explore alternative indigenous species that can be used as replacements that may offer the same benefits derived from IAP by urban residents. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-10-14
Mediating transition to household electricity conservation through co-designing in Makhanda, South Africa
- Authors: Mutumbi, Uzziah
- Date: 2022-04-06
- Subjects: Households Energy consumption South Africa Makhanda , Renewable energy sources South Africa , Consumer behavior South Africa Makhanda , Energy conservation South Africa Makhanda Citizen participation , Low-income consumers South Africa Makhanda
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291262 , vital:56838
- Description: Households consume up to 20% of total global electricity consumption, hence they are important role players in efforts for promoting sustainable consumption. Research on electricity-use behaviour and effectiveness of interventions is important for informing intervention strategies. However, relative to developed countries, research on this subject is lacking in developing countries, where electricity access is limited, and a substantial proportion of households are energy poor. The main goal of this study was to examine reported electricity-use behaviour and the effects of co-designed interventions on household electricity consumption in low-income households in Makhanda, South Africa, using a field-based experiment. Findings from self-reported electricity-use practices showed mixed results, with households reporting both good electricity-use behaviour (e.g., cooling down hot food before refrigeration) and wasteful actions (e.g., leaving appliances on standby). Results showed that electricity-use behaviour was influenced by socio-psychological values including universalism, benevolence, hedonism, and power. Over the intervention period, households exposed to co-designed electricity-saving interventions showed mean electricity savings of about 5.5%, while households in the Partial Treatment and Control group showed increased electricity consumption. Socio-demographic factors such as age and psychological factors (involvement and perceived behavioural control) were very important determinants of household consumption. Broadly, the findings empirically validate the impact of collective problem formulation and co-designing interventions in promoting sustainable actions. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Mutumbi, Uzziah
- Date: 2022-04-06
- Subjects: Households Energy consumption South Africa Makhanda , Renewable energy sources South Africa , Consumer behavior South Africa Makhanda , Energy conservation South Africa Makhanda Citizen participation , Low-income consumers South Africa Makhanda
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291262 , vital:56838
- Description: Households consume up to 20% of total global electricity consumption, hence they are important role players in efforts for promoting sustainable consumption. Research on electricity-use behaviour and effectiveness of interventions is important for informing intervention strategies. However, relative to developed countries, research on this subject is lacking in developing countries, where electricity access is limited, and a substantial proportion of households are energy poor. The main goal of this study was to examine reported electricity-use behaviour and the effects of co-designed interventions on household electricity consumption in low-income households in Makhanda, South Africa, using a field-based experiment. Findings from self-reported electricity-use practices showed mixed results, with households reporting both good electricity-use behaviour (e.g., cooling down hot food before refrigeration) and wasteful actions (e.g., leaving appliances on standby). Results showed that electricity-use behaviour was influenced by socio-psychological values including universalism, benevolence, hedonism, and power. Over the intervention period, households exposed to co-designed electricity-saving interventions showed mean electricity savings of about 5.5%, while households in the Partial Treatment and Control group showed increased electricity consumption. Socio-demographic factors such as age and psychological factors (involvement and perceived behavioural control) were very important determinants of household consumption. Broadly, the findings empirically validate the impact of collective problem formulation and co-designing interventions in promoting sustainable actions. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04-06
Soil and vegetation recovery following Acacia dealbata clearing in the Tsitsa catchment, Eastern Cape Province of South Africa: implications for ecological restoration
- Authors: Balintulo, Putuma
- Date: 2022-04-06
- Subjects: Acacia South Africa Eastern Cape , Invasive plants South Africa Eastern Cape , Working for Water Programme , Soil restoration South Africa Eastern Cape , Plant nutrients South Africa Eastern Cape , Restoration ecology South Africa Eastern Cape , Clearing of land South Africa Eastern Cape , Legacy effect
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290778 , vital:56783
- Description: Invasion by alien plant species in South Africa continues to compromise the stability of ecosystems by causing declines in biodiversity, altering soil nutrients and processes, and subsequently transforming ecosystem functionality. Control of invasive alien plant species has been widely implemented in South Africa to minimize their negative impacts; however, the legacy effects can persist long after the plant has been removed. The impacts of Acacia dealbata clearing on soil properties and native vegetation recovery remains understudied despite their significance in ecological restoration and monitoring. This comparative study determined the impacts of A. dealbata clearing on both soil physicochemical properties and vegetation in the Eastern Cape Province of South Africa. Soils were collected from three different clearing treatments, namely, cleared, invaded, and uninvaded, on 5 m x 5 m plots over three summer months. The plots were replicated four times for each clearing treatment, making a total of 72 sampling plots. Soils were assessed for soil pH, resistivity, P, C, N, and exchangeable cations as well as soil moisture content, penetration resistance, infiltration rate, hydraulic conductivity, and water repellency. Clearing of A. dealbata did not have any significant effects on most soil nutrients, however, there were variations in soil pH, resistance, and Na. Soil pH was significantly higher in the uninvaded treatments than in the cleared and invaded treatments. Soil moisture content was significantly higher in the cleared treatments than the adjacent invaded and uninvaded treatments, but this was observed in the month of December only. Soil penetration resistance and infiltration rates were significantly higher in the month of December in the cleared treatments. For all clearing treatments, no significant differences were recorded for soil hydraulic conductivity. These results on changes in soil properties following A. dealbata clearing are varied, with some soil properties showing decreases, an indication that removal of A. dealbata has the potential to shift soil properties towards a positive recovery trajectory. This study further assessed whether the clearing of A. dealbata facilitates the recovery of native plant species. Vegetation surveys were conducted in the three above-mentioned treatments and plots. Results showed little recruitment of native grasses and forbs, but the persistence of A. dealbata seedlings in the cleared treatments. Species richness and Shannon-Wiener diversity index were significantly (P < 0.05) higher in the cleared and invaded treatments than the uninvaded treatments, and this was more visible for trees and shrubs. Cover for all species was significantly higher (P < 0.05) in the uninvaded than the cleared and invaded treatments. This study observed the recruitment of some native species in the cleared treatments that were not present in the invaded treatments. Therefore, the recruitment and establishment of some native species, mostly grasses, in the cleared treatments gives assurance that passive restoration is on a positive vegetation recovery trajectory that can lead to recovery of native vegetation after A. dealbata clearing. Therefore, the study concludes that investing in ecological restoration after alien plant clearing is a necessity for complete ecosystem recovery to be achieved. Overall, the study concludes that the removal of A. dealbata triggers changes to some soil properties. Similarly, the study observed recruitment of some native grasses in cleared areas, an indication that alien plant clearing facilitates changes in both soil properties and vegetation. However, soil and vegetation recovery are being hampered by the regrowth of A. dealbata and secondary invaders that were observed in the cleared treatments. Two key recommendations of this study are (i) clearing follow-up to remove recruiting seedlings of invasive plant species and secondary invaders should be timeous and well-funded, and (ii) active restoration should be considered to speed-up soil and vegetation recovery processes. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Balintulo, Putuma
- Date: 2022-04-06
- Subjects: Acacia South Africa Eastern Cape , Invasive plants South Africa Eastern Cape , Working for Water Programme , Soil restoration South Africa Eastern Cape , Plant nutrients South Africa Eastern Cape , Restoration ecology South Africa Eastern Cape , Clearing of land South Africa Eastern Cape , Legacy effect
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290778 , vital:56783
- Description: Invasion by alien plant species in South Africa continues to compromise the stability of ecosystems by causing declines in biodiversity, altering soil nutrients and processes, and subsequently transforming ecosystem functionality. Control of invasive alien plant species has been widely implemented in South Africa to minimize their negative impacts; however, the legacy effects can persist long after the plant has been removed. The impacts of Acacia dealbata clearing on soil properties and native vegetation recovery remains understudied despite their significance in ecological restoration and monitoring. This comparative study determined the impacts of A. dealbata clearing on both soil physicochemical properties and vegetation in the Eastern Cape Province of South Africa. Soils were collected from three different clearing treatments, namely, cleared, invaded, and uninvaded, on 5 m x 5 m plots over three summer months. The plots were replicated four times for each clearing treatment, making a total of 72 sampling plots. Soils were assessed for soil pH, resistivity, P, C, N, and exchangeable cations as well as soil moisture content, penetration resistance, infiltration rate, hydraulic conductivity, and water repellency. Clearing of A. dealbata did not have any significant effects on most soil nutrients, however, there were variations in soil pH, resistance, and Na. Soil pH was significantly higher in the uninvaded treatments than in the cleared and invaded treatments. Soil moisture content was significantly higher in the cleared treatments than the adjacent invaded and uninvaded treatments, but this was observed in the month of December only. Soil penetration resistance and infiltration rates were significantly higher in the month of December in the cleared treatments. For all clearing treatments, no significant differences were recorded for soil hydraulic conductivity. These results on changes in soil properties following A. dealbata clearing are varied, with some soil properties showing decreases, an indication that removal of A. dealbata has the potential to shift soil properties towards a positive recovery trajectory. This study further assessed whether the clearing of A. dealbata facilitates the recovery of native plant species. Vegetation surveys were conducted in the three above-mentioned treatments and plots. Results showed little recruitment of native grasses and forbs, but the persistence of A. dealbata seedlings in the cleared treatments. Species richness and Shannon-Wiener diversity index were significantly (P < 0.05) higher in the cleared and invaded treatments than the uninvaded treatments, and this was more visible for trees and shrubs. Cover for all species was significantly higher (P < 0.05) in the uninvaded than the cleared and invaded treatments. This study observed the recruitment of some native species in the cleared treatments that were not present in the invaded treatments. Therefore, the recruitment and establishment of some native species, mostly grasses, in the cleared treatments gives assurance that passive restoration is on a positive vegetation recovery trajectory that can lead to recovery of native vegetation after A. dealbata clearing. Therefore, the study concludes that investing in ecological restoration after alien plant clearing is a necessity for complete ecosystem recovery to be achieved. Overall, the study concludes that the removal of A. dealbata triggers changes to some soil properties. Similarly, the study observed recruitment of some native grasses in cleared areas, an indication that alien plant clearing facilitates changes in both soil properties and vegetation. However, soil and vegetation recovery are being hampered by the regrowth of A. dealbata and secondary invaders that were observed in the cleared treatments. Two key recommendations of this study are (i) clearing follow-up to remove recruiting seedlings of invasive plant species and secondary invaders should be timeous and well-funded, and (ii) active restoration should be considered to speed-up soil and vegetation recovery processes. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04-06
Effects of elevated temperature, rainfall and soil nutrients on acacia mearnsii invasion
- Authors: Kharivha, Tshililo
- Date: 2021-10
- Subjects: Acacia mearnsii , Acacia mearnsii Effect of high temperatures on South Africa , Acacia mearnsii Climatic factors South Africa , Plant invasions South Africa , Invasive plants , Climatic changes South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/189997 , vital:44954
- Description: Climate change is associated with the risk of plant invasion hence a better understanding of the effects of elevated temperature, precipitation and soil nutrients on dominant invasive plants is needed for effective ecological planning. This study was set out to: (i) examine how elevated temperature (±2°C increase), (ii) high (above local average) and low (below local average) precipitation, (iii) elevated soil nutrient content (increase in soil N), and (iv) a combination of the above manipulations affects germination and growth of Acacia mearnsii, a dominant invasive plant in South Africa. The study further evaluated how the above-mentioned treatments affect soil chemical properties following A. mearnsii germination and growth. The above-mentioned specific objectives were tested under manipulated greenhouse conditions over six experimental months. The results indicated that the above-mentioned climate change scenarios have the potential to facilitate germination and growth of the invasive species A. mearnsii, and this is likely to proliferate its invasion in future. Results showed that seed germination was significantly high under all climate change manipulation treatments (˃50%) with highest seed germination recorded under high rainfall treatment (64%). Plant height was significantly higher under high temperature and high rainfall treatments throughout all the experimental months, though it was lowest under high nitrogen and combined treatment with high rainfall. The numbers of branches were high under higher temperature and low rainfall treatments than under high rainfall, high nitrogen and both combined treatments of low and high rainfall. Relative to the control, plants grown under climate change scenarios increased their root lengths, but this varied across different treatments. Total dry biomass was relatively high under high temperature treatment (0,7 g). Lower plant dry biomass was observed under low and high rainfall treatments (0,4 g), high nitrogen and combined treatments with both low and high rainfall treatments (0,1 g). Concerning the effects of climate change scenarios on soil chemical properties, soil pH levels were significantly higher after A. mearnsii germination and growth than before the experiment was setup. Soil resistivity was significantly higher in climate change treatments receiving nitrogen and combined treatments of low rainfall than other treatments and the soils before experiment. Soil total P was significantly higher in all the climate change treatments after A. mearnsii germination experiment than the before experiment soils. Soils receiving high temperature, high nitrogen, and combined treatment of low rainfall had significantly higher soil total N than other treatments and the before experiment soils. Soil total C was significantly higher in soils receiving high temperature, high nitrogen, and combined treatment of low rainfall after A. mearnsii germination than other treatments and before experiment soils. The findings suggest that future climate change scenarios of increased temperature and rainfall with soil nutrients could considerably enhance growth and germination success of the invasive plant A. mearnsii. Similarly, climate change scenarios could enhance some soil nutrient properties, which in turn, is likely to give the invasive plant A. mearnsii a germination and growth advantage. These results are the first in South Africa to show that future climate changes have the potential to facilitate A. mearnsii germination and growth, making it more invasive. The findings have implications for invasive plants management, especially action for managing the plant through clearing of the plant in sensitive ecosystems (e.g. riparian systems). , Thesis (MSc) -- Faculty of Science, Environmental Science, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Kharivha, Tshililo
- Date: 2021-10
- Subjects: Acacia mearnsii , Acacia mearnsii Effect of high temperatures on South Africa , Acacia mearnsii Climatic factors South Africa , Plant invasions South Africa , Invasive plants , Climatic changes South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/189997 , vital:44954
- Description: Climate change is associated with the risk of plant invasion hence a better understanding of the effects of elevated temperature, precipitation and soil nutrients on dominant invasive plants is needed for effective ecological planning. This study was set out to: (i) examine how elevated temperature (±2°C increase), (ii) high (above local average) and low (below local average) precipitation, (iii) elevated soil nutrient content (increase in soil N), and (iv) a combination of the above manipulations affects germination and growth of Acacia mearnsii, a dominant invasive plant in South Africa. The study further evaluated how the above-mentioned treatments affect soil chemical properties following A. mearnsii germination and growth. The above-mentioned specific objectives were tested under manipulated greenhouse conditions over six experimental months. The results indicated that the above-mentioned climate change scenarios have the potential to facilitate germination and growth of the invasive species A. mearnsii, and this is likely to proliferate its invasion in future. Results showed that seed germination was significantly high under all climate change manipulation treatments (˃50%) with highest seed germination recorded under high rainfall treatment (64%). Plant height was significantly higher under high temperature and high rainfall treatments throughout all the experimental months, though it was lowest under high nitrogen and combined treatment with high rainfall. The numbers of branches were high under higher temperature and low rainfall treatments than under high rainfall, high nitrogen and both combined treatments of low and high rainfall. Relative to the control, plants grown under climate change scenarios increased their root lengths, but this varied across different treatments. Total dry biomass was relatively high under high temperature treatment (0,7 g). Lower plant dry biomass was observed under low and high rainfall treatments (0,4 g), high nitrogen and combined treatments with both low and high rainfall treatments (0,1 g). Concerning the effects of climate change scenarios on soil chemical properties, soil pH levels were significantly higher after A. mearnsii germination and growth than before the experiment was setup. Soil resistivity was significantly higher in climate change treatments receiving nitrogen and combined treatments of low rainfall than other treatments and the soils before experiment. Soil total P was significantly higher in all the climate change treatments after A. mearnsii germination experiment than the before experiment soils. Soils receiving high temperature, high nitrogen, and combined treatment of low rainfall had significantly higher soil total N than other treatments and the before experiment soils. Soil total C was significantly higher in soils receiving high temperature, high nitrogen, and combined treatment of low rainfall after A. mearnsii germination than other treatments and before experiment soils. The findings suggest that future climate change scenarios of increased temperature and rainfall with soil nutrients could considerably enhance growth and germination success of the invasive plant A. mearnsii. Similarly, climate change scenarios could enhance some soil nutrient properties, which in turn, is likely to give the invasive plant A. mearnsii a germination and growth advantage. These results are the first in South Africa to show that future climate changes have the potential to facilitate A. mearnsii germination and growth, making it more invasive. The findings have implications for invasive plants management, especially action for managing the plant through clearing of the plant in sensitive ecosystems (e.g. riparian systems). , Thesis (MSc) -- Faculty of Science, Environmental Science, 2021
- Full Text:
- Date Issued: 2021-10
Perceptions of the role of Lantana camara on human well-being and rural livelihoods in Vhembe Biosphere Reserve, South Africa
- Authors: Mhlongo, Edward Swazi
- Date: 2021-04
- Subjects: Lantana camara -- South Africa -- Vhembe District Municipality , Introduced organisms -- South Africa -- Vhembe District Municipality , Biological invasions -- South Africa -- Vhembe District Municipality , Plant invasions -- South Africa -- Vhembe District Municipality , Lantana camara -- Control -- South Africa -- Vhembe District Municipality , South Africa -- Rural conditions , Ethnoscience -- South Africa -- Vhembe District Municipality
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/177952 , vital:42893
- Description: In the past, social aspects on biological invasions were less documented, this hindered the development of sound and effective management of Invasive Alien Species (IAS). However, there has been a shift in trends with more studies on biological invasions integrating local knowledge together with ecological studies to develop effective management interventions. Invasive Alien Species are widespread throughout Southern Africa and are usually prevalent in the rural areas. Limpopo province consists of large rural areas where people depend on natural resources, wild and exotic species for their livelihoods. Lantana camara is one of the major invaders that is problematic worldwide having detrimental impacts on biodiversity, ecosystem functions, and economies. This study assessed the perceptions of the role of L. camara on the well-being and rural livelihoods of local communities in the Vhembe Biosphere Reserve using household surveys. A total of 300 surveys were administered in six villages. The study further used a two-pronged approach to examine invasion extent and management options. The two-pronged approach included (i) detailed vegetation surveys in 50 household yards within each village, and (ii) focus group to solicit local knowledge of invasion extent and managing L. camara by the rural communities. The results of the study showed that almost all the respondents knew L. camara and could describe it. Most of the respondents were of the view that L. camara had no negative impacts on their livelihoods. Other respondents stated costs associated with L. camara were more than benefits and wanted a reduction in L. camara densities in the area. Most respondents wanted more government intervention to help in managing L. camara, this is because of the perceived future impacts of L. camara. Vegetation survey results showed no significant difference in L. camara abundances and plant heights among the six study villages. The average number of L. camara counted per household yard in all villages was (2.41 ± 0.20) plants, with average plant basal diameter of (0.94 ± 0.02 cm). There were significant differences in canopy width of L. camara among the six study villages. Plant basal diameter was high in Tshakhuma (1.05 ± 0.04 m) and Duthuni (1.00 ± 0.04 m) villages, and low in Ha Mutsha village (0.82 ± 0.03 m). Lantana camara canopy width at household level across all villages averaged 1.34 ± 0.03 m. Canopy cover was high in Tshakhuma village (1.70 ± 0.09 m) and low at Ha Mutsha village (1.03 ± 0.03 m). In all six village focus group discussions, it was noted that mechanical clearing of L. camara was the most used method, but they reported minimum help from the government particularly Working for Water (WfW). The study concludes that L. camara has no substantial adverse impacts to most of the respondents. The study further noted that L. camara is dominant in most household yards ii and that management is taking place however current control options are not enough on their own. Suggestions for further research are to explore more alternative indigenous species present or easily accessible to the community members which may offer the same benefits as IAS. Furthermore, additional research at local level is required for implementing management techniques best suited for the area. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mhlongo, Edward Swazi
- Date: 2021-04
- Subjects: Lantana camara -- South Africa -- Vhembe District Municipality , Introduced organisms -- South Africa -- Vhembe District Municipality , Biological invasions -- South Africa -- Vhembe District Municipality , Plant invasions -- South Africa -- Vhembe District Municipality , Lantana camara -- Control -- South Africa -- Vhembe District Municipality , South Africa -- Rural conditions , Ethnoscience -- South Africa -- Vhembe District Municipality
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/177952 , vital:42893
- Description: In the past, social aspects on biological invasions were less documented, this hindered the development of sound and effective management of Invasive Alien Species (IAS). However, there has been a shift in trends with more studies on biological invasions integrating local knowledge together with ecological studies to develop effective management interventions. Invasive Alien Species are widespread throughout Southern Africa and are usually prevalent in the rural areas. Limpopo province consists of large rural areas where people depend on natural resources, wild and exotic species for their livelihoods. Lantana camara is one of the major invaders that is problematic worldwide having detrimental impacts on biodiversity, ecosystem functions, and economies. This study assessed the perceptions of the role of L. camara on the well-being and rural livelihoods of local communities in the Vhembe Biosphere Reserve using household surveys. A total of 300 surveys were administered in six villages. The study further used a two-pronged approach to examine invasion extent and management options. The two-pronged approach included (i) detailed vegetation surveys in 50 household yards within each village, and (ii) focus group to solicit local knowledge of invasion extent and managing L. camara by the rural communities. The results of the study showed that almost all the respondents knew L. camara and could describe it. Most of the respondents were of the view that L. camara had no negative impacts on their livelihoods. Other respondents stated costs associated with L. camara were more than benefits and wanted a reduction in L. camara densities in the area. Most respondents wanted more government intervention to help in managing L. camara, this is because of the perceived future impacts of L. camara. Vegetation survey results showed no significant difference in L. camara abundances and plant heights among the six study villages. The average number of L. camara counted per household yard in all villages was (2.41 ± 0.20) plants, with average plant basal diameter of (0.94 ± 0.02 cm). There were significant differences in canopy width of L. camara among the six study villages. Plant basal diameter was high in Tshakhuma (1.05 ± 0.04 m) and Duthuni (1.00 ± 0.04 m) villages, and low in Ha Mutsha village (0.82 ± 0.03 m). Lantana camara canopy width at household level across all villages averaged 1.34 ± 0.03 m. Canopy cover was high in Tshakhuma village (1.70 ± 0.09 m) and low at Ha Mutsha village (1.03 ± 0.03 m). In all six village focus group discussions, it was noted that mechanical clearing of L. camara was the most used method, but they reported minimum help from the government particularly Working for Water (WfW). The study concludes that L. camara has no substantial adverse impacts to most of the respondents. The study further noted that L. camara is dominant in most household yards ii and that management is taking place however current control options are not enough on their own. Suggestions for further research are to explore more alternative indigenous species present or easily accessible to the community members which may offer the same benefits as IAS. Furthermore, additional research at local level is required for implementing management techniques best suited for the area. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2021
- Full Text:
- Date Issued: 2021-04
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