Carbon and nutrient storage of the Swartkops Estuary salt marsh and seagrass habitats
- Authors: Els, Jessica
- Date: 2019
- Subjects: Estuarine ecology -- South Africa -- Swartkops River Estuary , Salt marsh ecology -- South Africa -- Swartkops River Estuary Seagrasses -- Ecology Seagrasses -- Conservation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42196 , vital:36634
- Description: Coastal wetlands play an important role in filtering nutrient contaminants from water bodies and are also effective carbon sinks. These systems are known as blue carbon ecosystems. Blue carbon is defined as the carbon stored and sequestered by coastal vegetated habitats such as seagrasses, salt marsh and mangroves. These habitats are being lost on a global scale due to climate change and other anthropogenic pressures. Quantifying ecosystem services provided by these habitats may lead to better conservation and restoration strategies. Research on this topic has escalated over the past decade but there are no published studies in South Africa. The aim of this study was to quantify the carbon, nitrogen, and phosphorus stocks in the above and below ground tissues of Zostera capensis, Spartina maritima, and Salicornia tegetaria — a seagrass, salt marsh grass, and salt marsh succulent. This was done in both summer and winter to understand the variability of carbon and nutrient storage. The organic carbon stock of the sediment beneath these three species was also quantified. Results showed that S. maritima, S. tegetaria, and Z. capensis stored 16 ± 2.9 Mg C. ha-1, 4.3 ± 0.7 Mg C. ha-1, and 2.1 ± 0.5 Mg C. ha-1 in their respective biomass, and 247 ± 48 Mg C. ha-1, 212 ± 44 Mg C. ha-1, and 224 ± 38 Mg C. ha-1 respectively in the sediment beneath these habitats. This was determined by elemental analysis and the loss on ignition method (LOI). The sediment made up the dominant carbon pool in the estuary and there was very little seasonal variation, however spatial variation was evident. The sediment carbon stocks were similar to the global mean for salt marsh (255 Mg C. ha-1) and greater than the global mean for seagrass (108 Mg C. ha-1). The Swartkops Estuary stored a total (biomass and sediment carbon combined) of 14 094 Mg C in the Z. capensis area of 62 ha, 25 286 Mg C in the S. maritima area of 96 ha, and 5 916 Mg C in the S. tegetaria, covering an area of 27 ha. This is significantly less than what has been found globally in estuaries, but this is largely due to the smaller area cover of these macrophytes. The amount of carbon stored per hectare is much larger in this South African system than in many international studies — possibly due to the high levels of pollution coming into the system. Nitrogen and phosphorus stocks in the plants fluctuated seasonally in relation to the nutrient input to the estuary, with the greatest stocks found in winter in Z. capensis, S. maritima, and S. tegetaria (0.42 ± 0.03 Mg N. ha-1, 1.6 ± 0.13 Mg N. ha-1, and 0.37 ± 0.02 Mg N. ha-1, respectively; and 0.4 ± 0.03 Mg P. ha-1, 1.2 ± 0.10 Mg P. ha-1 in Z. capensis and S. maritima respectively) because nutrient inputs to the system were highest in winter, however the P stocks in S. tegetaria were greatest in summer (0.35 ± 0.04 Mg P. ha-1). The reason for this difference is because of their ability to store phosphorus better than nitrogen and for longer periods of time due to luxury uptake. Salicornia tegetaria N and P stocks were also lower than the other two species, possibly due to its placement along the intertidal gradient, as it is not tidally inundated for as long as the other two species. The Z. capensis and S. maritima at Site 1 showed extremely high amounts of nitrogen in their tissues (105.3 ± 1.6 g kg-1 and 74.91 ± 4.1 g kg-1 respectively). This is due to the area being a depositional site as it was an old oyster farm and experiences little tidal flushing from the sea despite its proximity to the mouth. Nutrient ratios and N: biomass were determined as an indication of nutrient pollution. The N: biomass was low in both seasons in Z. capensis, S. maritima, and S. tegetaria (0.08, 0.02, 0.04 respectively) indicating consistant eutrophic conditions in the estuary. Plant biomass was a better indicator of nutrient pollution than epiphytes which were very low in the Swartkops Estuary and did not prove as a useful indicator of nutrient enrichment. These results can inform local management plans of the ecosystem service potential of these species and how they should be protected for future and current sustainable use as filters for nutrient pollution to keep the water quality in a better state. It also outlines the current state of blue carbon and nutrient stocks in an urban South African estuary.
- Full Text:
- Date Issued: 2019
Evaluating Livestock Development Programmes through the Production Risk Interface: Case of the Kaonafatso ya Dikgomo (KyD) Scheme in South Africa
- Authors: Ngarava, Saul
- Date: 2019
- Subjects: Livestock projects
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/15730 , vital:40513
- Description: Livestock is significant in the livelihoods of the rural poor, providing a plethora of benefits. Livestock Development Programmes (LDPs) can transform smallholder farmers’ production for increased production and poverty reduction. The Kaonafatso ya Dikgomo (KyD) Scheme is a LDP implemented in South Africa with the aim of assisting smallholder farmers to attain economic and sustainable beef production. The literature shows that most evaluations of LDPs have been quantitative based on measurable and quantifiable metrics. Furthermore, various socio-economic and institutional factors have a bearing on the decision to participate in LDPs and eventually adopting the practices. Impact assessments of LDPs have been devoid of risk consideration as well as ascertaining how risk introduced by participating in LDPs has impacted productivity. The overall objective of the study was therefore to evaluate LDPs, focussing on benefits, participation and risk. The specific objectives of the study entailed developing a conceptual tool for measuring the qualitative and secondary benefits. Secondly, it was to determine factors influencing participation decisions in the KyD Scheme. Thirdly, the study sought to measure and compare calving rate and off-take rate risk between KyD Scheme participants and non-participants. Lastly, the study highlighted the variability (risk) introduced by participating in a LDP and its impact on production. The study utilised a cross-sectional survey of KyD Scheme participants and nonparticipants in KwaZulu-Natal, Limpopo and Eastern Cape Provinces of South Africa. Non-probability convenience sampling method was utilised in selecting a sample of 164 KyD Scheme participants and 81 non-participants. A semi-structured questionnaire was the data collection tool utilised. A conceptual “Livelihood Effect Benefit Index”; Probit, Tobit and Ordered Probit models; Just and Pope Production function; Propensity Score Matching; and Monte Carlo Simulations were utilised to analyse data. Statistical Package for Social Scientists version 24, STATA 13 and @Risk Decision Tool were the analytical packages utilised in analysing the data. The study found that the Scheme provided low qualitative benefits, mainly through social capital. Furthermore, socio-economic and institutional factors have significant impact on the decision to participate in the Scheme, extent of participation and decision to continue practicing Scheme experiences. In comparing the two groups of Scheme and Scheme non-participants, calving and off-take risk for KyD Scheme participants was lower than that of Scheme non-participants. In comparing individuals with similar characteristics between the two groups, Scheme participants reduced calving risk whilst increasing the off-take risk. Page | vi The study concluded that the Scheme exhibited low qualitative benefits. Furthermore, the decisions to participate and the extent of participation in the KyD Scheme were influenced by various socio-economic and institutional factors, which were however more favourable to resource endowed smallholder farmers. In addition, the Scheme had significant impact on production risk. The risk reducing determinants appeared to also favour more resource endowed smallholder farmers who had more farming experience. The study’s recommendations were subdivided into short term, medium term and long term. The short term recommendations included targeting farmers within a distance of between 30km and 90km from a formal market, promoting dipping services-based training and extension, and providing information and training concerning calving i.e. animal health, husbandry and breed selection for herd maximization. Participation in the Scheme and the extent of participation can be improved through enhancing awareness of the Scheme at various points where stock feed are available to farmers. Furthermore, enhanced cooperation with extension workers provides a conduit in improving awareness of the Scheme and enhancing participation. The medium term recommendations pertained to initiatives such as promoting other livelihood options to enhance benefits of the programme, and promoting social capital enhancing initiatives such as mentoring and providing social capital objectives that can be integrated into the overall livestock sector strategy. The long-term recommendations include initiatives such as subsidizing increase in herd size to between 50 and 120 cattle, maintaining a monthly frequency of farmer-extension contact of between 2 and 5 times per month, as well as incorporating calving and off-take risk in policy formulation, implementation and evaluation
- Full Text:
- Date Issued: 2019
The perspectives of victims of domestic violence and abuse: narratives from members of Masimanyane women’s support centre in East London, Eastern Cape Province, Resa.
- Authors: Sigodla, Asavela
- Date: 2019
- Subjects: Family violence Abused women
- Language: English
- Type: Thesis , Masters , MSoc (Criminology)
- Identifier: http://hdl.handle.net/10353/16419 , vital:40718
- Description: Domestic violence and abuse also known as Gender-based violence (GBV) including rape, mutilation, murder and sexual abuse, is a profound health problem for women across the globe. Although domestic violence and sexual abuse is a significant cause of female morbidity and mortality, it is almost never seen as a public health issue. Domestic violence and abuse can happen to anyone of any race, age, sexual orientation, religion or gender. This study draws attention on exploring victim’s narrative perspectives on domestic violence and abuse against women in East London at Masimanyane Women’s Support Centre (MWSC) in Eastern Cape Province of South Africa. The study employed a qualitative research approach, with In-Depth Interviews (IDI), Focus Group Discussions (FDGs), and review of related literature for data collection. The findings of this study were based only from participants who were victims of domestic violence and abuse, as some of the views were stated by visitors. This resulted in some situations where the witnesses of domestic violence and abuse, just like victims themselves did not want to report their incidents. Women may not reveal that they are suffering from domestic violence and abuse, as they fear of the image that they may be portraying about themselves and their family as a whole like social pressure and stigma of defamation. Although domestic abuse and violence increases all the time women are encouraged to open up on such cases about abuse. Real change in these cases can only be brought by changing the mind-set of society through education and better law enforcement. This study was anchored by both the Social Learning Theory and Feminist Theory. Upon recommendations, this study has seen that there should be government interventions and programs that help victims of domestic violence and abuse and also to work in a way of preventing the domestic violence and abuse.
- Full Text:
- Date Issued: 2019