Woody encroachment and plant-root soil interactions in a semi-arid savanna
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12139 , vital:39174
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceous species composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands, management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
Woody encroachment and plant-root soil interactions in a semi-arid savanna
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12053 , vital:39131
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceousspecies composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
Water restriction and vitamin c supplementation on Xhosa goats during summer: Effect on growth performance, blood biochemical profile, nutrient balance, carcass characteristics and meat quality
- Authors: Akinmoladun, Oluwakamisi Festus https://orcid.org/0000-0001-6462-374X
- Date: 2020-08
- Subjects: Goats -- Nutrition , Goats -- Feeding and feeds
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22710 , vital:52664
- Description: This study aimed to evaluate the effect of single and extra vitamin C (VC) supplementation on water-stressed Xhosa goats during the summer by evaluating their growth performance, blood biochemical profile, nutrient balance, carcass characteristics and meat qualities. The objectives were to assess the effect of water restriction and vitamin C supplementation by evaluating: firstly, growth performance, heat tolerance responses, and blood metabolites; secondly, intake, nutrient digestibility, nitrogen and mineral balance; thirdly, stress indices, carcass characteristics and meat qualities parameters and lastly, fatty acid profile, oxidative stability of lipids and sensory attributes were evaluated. To achieve these objectives, forty-two (42) goats were divided equally into seven treatments (75-day trial); without water restriction (W0, control); water restriction of 70percent of ad libitum water intake WI (W70); water restriction of 50percent ad libitum WI (W50); water restriction of 70percent of ad libitum WI plus 3g VC daily (W70+); water restriction 50percent of ad libitum WI plus 3g VC daily (W50+); water restriction of 70percent of ad libitumWI plus 3g VC and extra 5gVC given every eight-day (70++); water restriction of 50percent of ad libitum WI plus 3g VC and extra 5gVC given every eight-day (W50++). In the first objective, growth performance parameters, body condition scores, rectal temperature, respiratory rate, heat tolerance response parameters and blood metabolites were measured.Weight loss due to water restriction was reduced by VC supplementation in treated groups. The attenuation effect of VC was significant (P<0.05) in responses to respiratory rate (RR), Na+, K+, Mg2+, Cl-, Ca2+ and urea. Supplementation of VC (either single or multiple) did not (P>0.05) improve the effect of water restriction on body condition scores (BCs), FAMACHA©, glucose, globulin, alanine aminotransferase (ALT) and high-density lipoprotein (HDL). In the second objective, intake, nutrient digestibility, nitrogen and mineral balance were evaluated. The reduced nutrient intake was similar (P>0.05) irrespective of water restrictions and VC supplementations. Water-restriction levels did not affect nutrient intake/metabolic weight. Retained nitrogen increased with water-restriction levels but not influenced by VC. NH3-N decreased with the levels of water restriction while the pH was similar across the water restricted groups. Supplementation of VC had no effect (P>0.05) on apparent digestibility and digestible nutrients induced by water restriction levels. The amount of Ca, K, Mg retained increased (P<0.05) with water-restriction levels. In the third objective, stress indices, carcass characteristics and meat quality parameters were evaluated. The level of plasma cortisol concentration due to water stress was lessened (P<0.05) by VC. Follicle stimulating hormone (FSH), Luteinizing hormone (LH) and insulin were not affected (P>0.05) by levels of water restriction. The hot and carcass weights were lower (P<0.05) in W70+ and W50+ compared to W70 and W50 respectively. Vitamin C treated goats had higher redness (a*) compared to W70, W50 and W0. The shear force and cooking loss increased (P<0.05) with water restriction levels, while thaw loss, pH45min and pH24h were not affected by water restriction levels. In the final objective, the treatments did not affect (P>0.05) the oxidative stability of lipids (TBARS). The moisture and fat content in the water restricted groups were lower (P<0.05) than W0. The consumer meat sensory appearance decreased (P<0.05) with levels of water restrictions. Regardless of VC concentration and supplementation, vaccenic, and docosahexaenoic acid increased (P<0.05) while linolenic acid decreased as the water restriction levels increased. Nonetheless, treatment did not affect (P>0.05) the saturated and unsaturated fatty acids. These studies showed that suboptimal water intake negatively affects the growth performance and nutrient intake of Xhosa goats. However, the reduction in body weight loss and decreased plasma cortisol (chief stress hormone) concentration following vitamin C supplementation (especially at a daily single dose [3g/d]) may well reduce the effect of water stress in goats. , Thesis (PhD) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-08
Waste keratinous biomass valorization and characterization of keratinases produced by exiguobacteria species
- Authors: Dlume, Tutuka
- Date: 2021-02
- Subjects: Factory and trade waste -- Biodegradation , Bioremediation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20695 , vital:46438
- Description: Keratinous wastes are emanating in a million tons, as by-products, from various agro-industrial processing plants. Consequently, they create a serious solid waste problem in the environment due to poor handling. Microbial keratinases are proteolytic enzymes that effectively participate in keratin-rich biomass hydrolyses such as feathers, nail, hair, hooves, and horns. Therefore, proper management of these wastes via recycling into useful products is ecologically imperative. Biodegradation of keratin-rich biomass has been identified as an economical and environmentally friendly way of transforming these recalcitrant agro wastes into useful products, hence the motivation for this study. Feather degrading bacterial strains previously isolated from a municipal dumpsite and coded as SSB-02 and SSB-03 was identified through 16S rDNA sequencing and phylogenetic analysis. The fermentation conditions for keratinase production were optimized. The protein and amino acids constituents of the hydrolyzed chicken feather were analyzed. The biochemical properties of the keratinase produced were determined. Also, the effect of laundry detergents on the stability of the keratinase was studied. The isolates coded as SSB-02 and SSB-03 showed a high percentage of sequence homology with Exguobacterium spp., hence they were identified as Exiguobacterium sp. FBH5 and Exiguobacterium acetylicum FHBD, respectively. Exiguobacterium sp. FBH5 showed the highest extracellular keratinase production of 934.58 ± 27.27 U/mL at 72 h of incubation; in optimized fermentation conditions that included pH (5.0), temperature (30 oC), and chicken feather (0.5percent, w/v). Similarly, E. acetylicum FHBD displayed optimal keratinase production of 1023.64 ± 25.71 U/mL at 120 h of fermentation and improved fermentation conditions that involved pH (3.0), temperature (35 oC) and chicken feathers (0.5-1.5percent; w/v). The amino acid analysis showed that arginine, aspartic acid and glutamic acid were the most abundant amino acids cleaved from the degradation of chicken feathers by Exiguobacterium sp. FBH5 at a respective concentration of 1.16, 1.28 and 1.45 (g/100g sample). Additionally, hydrolysate that emanated from E. indicum FHBD degradation of feather showed high concentrations of arginine, serine, aspartic acid, glutamic acid, and glycine at the respective concentration (g/100g sample) of 1.2, 1.12, 1.34, 1.58 and 1.29. The keratinases were optimally active at pH and temperature of 8.0 and 50 oC, respectively. EDTA and PMSF did not highly repress keratinolytic proteases' activity, and this inhibitory pattern suggests that they may belong to a mixed protease family. Keratinase from E. acetylicum FHBD was highly stable in the presence of SDS, with 99percent residual activity and displayed variable stability in other chemical agents tested. A similar stability pattern was observed with keratinase from Exiguobacterium sp. FBH5, although the enzyme lost about 40percent of its original activity in the presence of SDS. Evaluation of metal ion stability indicated that E. acetylicum FHBD keratinase was remarkably stable in the presence of Fe3+, Mg2+, Cu2+, Zn2+, and Ba2+, with residual activity of 94percent, 88percent, 89percent, 90percent, and 97percent, respectively. Similarly, Exiguobacterium sp. FBH5 keratinase was considerably stable after treatment with Co2+, K+, and Zn2+ as it displayed a residual activity of 85percent, 84percent and 93percent, respectively. The study of the keratinases stability in laundry detergents showed that E. acetylicum FHBD keratinolytic proteases was activated in the presence of Omo, Surf, Sunlight, and Pro wash after 60 min of pre-incubation compared to 30 min, with residual activity of 94 ± 2.94percent, 91 ± 2.53percent, 95 ± 2.89percent and 87 ± 2.89percent respectively. Likewise, Exiguobacterium sp. FBH5 keratinase activity was promoted after 60 min of incubation compared to 30 min, with a residual enzyme activity of 79percent, 84percent, 101percent, 103percent and 105percent and 106percent for Ariel, Surf, Prowash, Freewave, Sky and Evaklin, respectively. Therefore Exiguobacterium spp., demonstrated excellent keratinolytic potentials that could be exploited for sustainable development of bio-innovative products. The study keratinases' properties suggest their industrial and biotechnological application potentials, especially as bio-additive in the formulation of laundry detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Vulnerability assessment of wetland ecosystems to water demand, climate variability and land-use/cover change: The case of Die Vlei wetland, Eastern Cape province, South Africa
- Authors: Gwena, Kudzanai Rosebud https://orcid.org/0000-0002-1032-8937
- Date: 2021-09
- Subjects: Water-supply , Climate change mitigation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22688 , vital:52656
- Description: Water scarcity is a major challenge in many different countries, particularly arid and or semi-arid like South Africa. Wetlands are one of the freshwater ecosystems that may assist in alleviating water scarcity because they are valuable not only as a water source for humans but also as an ecosystem of animals and plant species. However, wetlands have been experiencing rapid rates of vulnerability/risk due to alterations by population growth leading to enhanced water demand, climate variability, and human activities leading to land cover/land-use changes. Geographical Information Systems (GIS) and Remote Sensing (RS) are less financially taxing methods useful in studying water scarcity, as shown in this study. The study begins with a literature review presentation based on a desk study from predominantly academic publications and additional municipal and consultancy reports on the wetland ecosystem’s vulnerability/risk and focuses on applying GIS & RS in related studies. After that, the study conducts a vulnerability assessment using the Ramsar Convention’s wetland vulnerability assessment using the theoretical framework stages using GIS and RS technologies. The study hypothesizes that water demand, climate variability, and land-use/cover changes (LULC) are the tri-factor responsible for wetland vulnerability. It begins the assessment by first quantifying wetland water demand using the wetland water budget, ecosystem services and the Penman-Montheith-FAO (ETo) evapotranspiration index. Secondly, objectively representing climate variability on wetland vulnerability using trend analysis to measure rainfall and temperature variability. Thirdly, reconstructing LULC changes from multi-date remotely sensed SPOT imagery over ten years from 2007 to 2017 to identify and monitor impacts of trends. The vulnerability was assessed through a Principle Component Analysis (PCA) that identified relevant variables and Multi-Criteria Evaluation (MCE) to evaluate the wetland’s exposure. The study concludes that there is evidence of a possible increase in water demand whilst climate variability, which is estimated to have a 39% contribution to the wetland dynamics, is characterised by a decrease in precipitation and an increase in temperatures. Lastly, LULC trends showed a marked increase in domestic and commercial farming, and farming has been identified as a wetland stressor of note. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
Viability of government funded broiler production : lessons from Northern KwaZulu Natal, South Africa
- Authors: Mdletshe, Sifiso Themba Clement https://orcid.org/0000-0002-2668-0193
- Date: 2023-04
- Subjects: Broilers (Chickens) -- Economic aspects , Broilers (Poultry) , Broilers (Chickens) -- Breeding
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27843 , vital:69947
- Description: Generally, rural areas continue to experience high poverty levels and low incomes, which seem to be occasioned by high unemployment rates, limited educational attainments, and devastating floods and droughts. This situation is further exacerbated by increase in crime rates, making livelihoods even more difficult. To mitigate such adverse situations, rural households employ diverse strategies, including maintaining community gardens, one-home-one-garden schemes, as well as livestock and poultry production. The most prevalent livelihood strategy in South Africa or KwaZulu-Natal is broiler production, since it needs less space and a short production cycle compared to other livestock or crop enterprises. At the same time, income is generated over a short period. Besides, the government of KwaZulu Natal has actively intervened in the sector as part of its broader poverty reduction strategy and farmer support programmes. In KwaZulu-Natal Province, the provincial government has been supporting broiler producers for many years. While substantial research work has been done in the province on livelihood strategies, including livestock production on a province-wide basis, there is no information about how successful the broiler production funded by the government has being. Broader concerns about production problems have not been assuaged based on systematic studies and evidence. It is this wise that this study was initiated. The objective is to assess the economic viability of government-funded small-scale broiler projects in the KwaZulu-Natal Province of South Africa and determine the implications for poverty reduction and food security. Data were collected from the government-funded small-scale broiler producers that are residing in Northern KwaZulu-Natal districts uThungulu, Zululand and uMkhanyakude. A total of 75 small-scale broiler projects 25 broiler projects in each district were selected by probability sampling procedure for the interviews. Questionnaires that combined both close-ended and open-ended questions were used to collect primary data, which include production and marketing, as well as the factors that influence the profitability of the small-scale broiler projects. After collection, data were captured and encoded on spreadsheets in Microsoft Excel and exported to Statistical Package for the Social Science (SPSS) software version 26 and STATA for analyses. Descriptive statistics applied include frequencies and means. In addition, a gross margin (GM) and gross profit margin (GPM) analysis were employed to assess the profitability of government-funded small-scale broiler projects. Both profitability and gross margin analyses were used as proxies for farmers’ motivation and incentives to participate in broiler production. Further analyses were conducted to determine the model that best explains the underlying relationships. Initially, the Multiple Linear Regression Model was applied to determine the factors influencing the profitability of government-funded small-scale broiler projects. The indication was that while positive profits were revealed, the system seemed to fall short of its potential. In light of that, it was decided to fit another model to estimate the technical efficiency of the system and gain an understanding of the causes of any inefficiency that might exist in the production system. In that regard, the one-step Stochastic Frontier Model was employed to show that the technical efficiency of broiler production systems in the project area was positively and significantly influenced by flock size, the quantity of feeds and labour costs, while medication played no role possibly because of weak extension coverage. An inefficiency model fitted as part of the one-step model suggested that age, gender and educational level were significant influencers of technical inefficiency, with the possibility that the older the farmers, the more technically inefficient the system possibly because of the strenuousness of commercial poultry production. In addition, it was found that the more educated the farmer, the less inefficient the farm, which conversely means that the system becomes more efficient as the farmer receives more education. The negative coefficient of the gender variable also implies that for farms managed by female farmers, the system was less inefficient, which is more technically efficient, and this can be explained by women’s propensity to be more gentle, caring and sensitive in managing the chickens than their male counterparts. Heteroskedasticity tests and corrections were conducted in the one-step estimation technique to show that variations in the inefficiency term (μ) and the stochastic error term were explained by age and educational level for the most part. Clearly, improvements in the broiler industry in KwaZulu-Natal will depend to a large extent on the knowledge and experience of the farmers and substantial enlargement of the flock size of adequately fed birds. Attention to these elements is expected to have important practical implications for sustainable broiler poultry development and food security in the project area, as well as locations possessing identical features and characteristics. , Thesis (MSci) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023-04
Valorization of chicken feather through dekeratinization by keratinolytic Bacillus species to amino acid
- Authors: Matches, Lupho
- Date: 2021-02
- Subjects: Proteolytic enzymes , Poultry -- Processing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20451 , vital:45667
- Description: The poultry meat processing sector generates chicken feathers as by-products, and they are 90percent keratin in composition. Keratin is an insoluble and structural protein that shows recalcitrance to hydrolysis by classical proteolytic enzymes, including trypsin, pepsin, and papain. Keratinases are a group of proteolytic enzymes endowed with keratin degradation into peptides and amino acids. They are recently gaining traction for their multifaceted potential application in the green industrial space. Hence, keratinolytic bacteria previously isolated from dumpsite were identified using 16S rDNA sequencing. The optimal fermentation conditions were determined for enhanced extracellular keratinase production and chicken feather degradation. Also, the amino acid analysis of the chicken feather hydrolysates was carried out. The biochemical properties of the keratinases were also determined. Based on 16S rDNA sequencing and phylogenetic analysis, the isolates coded as SSN-02 and HSN-03 showed a high percentage of sequence homology with Bacillus spp.; hence, they were identified as Bacillus sp. NFH5 and Bacillus sp. FHNM, respectively. Bacillus sp. NFH5 showed optimal keratinase production of 1149.99 ± 80.99 U/mL after 96 h of incubation time, in optimized fermentation conditions that included pH (4.0), chicken feather (1.5percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). Similarly, Bacillus sp. FHNM demonstrated the maximum keratinase production of 480 ± 41.14 U/mL 144 h post cultivation, in optimized fermentation conditions with pH (7.0), chicken feather (2.0percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). For Bacillus sp. NFH5 chicken feather hydrolysate, the amino acids in relatively higher concentration (>1.0g/100g sample) include arginine (1.8), serine (1.16), aspartic acid (1.95), glutamic acid (2.47), proline (1.16) and glycine (1.45). Bacillus sp. FHNM feather hydrolysates, contained (g/100g of sample): arginine (1.9), serine (1.4), aspartic acid (2.5), glutamic acid (2.51), glycine (1.51), proline (1.13), leucine (1.030, histidine (1.25), and lysine (1.06) (g/100g of sample) in high concentration. The keratinases were optimally active at pH 8.0. Bacillus sp. FHNM showed an optimal temperature of 100 oC; while Bacillus sp. NFH5 keratinase displayed optimal activity at 90 oC. EDTA and 1,10-phenanthroline inhibited the keratinases, and the inhibition pattern indicated that they belong to metalloprotease. Keratinase from Bacillus sp. FHNM showed considerable residual activity in the presence of Co²⁺ (93percent), Fe³⁺ (99percent), and K⁺ (94percent). Bacillus sp. NFH5 keratinase retained 92percent, 92percent, 93percent of the original activity against Ba²⁺, Na⁺ and Fe³⁺ treatment. Bacillus sp. FHNM keratinase was remarkably stable after 60 min of detergents treatment with residual activity of 89percent, 96percent, 81percent, 73percent, 96percent, 88percent, 88percent and 98percent for Omo, Surf, Ariel, Sunlight, Prowash, Freshwave, Sky, and Evaklin, respectively. Maq impacted the enzyme stability negatively, with residual activity of 48percent after 60 min of incubation. Additionally, keratinase Bacillus sp. NFH5 retained 68percent, 78percent, 80percent, 84percent, 57percent, 80percent, 98percent, 106percent and 106percent of the original activity against Omo, Surf, Ariel, Sunlight, Maq, Prowash, Freshwave, Sky and Evaklin, respectively. Therefore, these results suggest that Bacillus spp. could be ideal candidates for sustainable production of active keratinases and valorization of the abundantly generated keratinous biomass. The stability displayed by keratinases from Bacillus sp. FHNM and Bacillus sp. NFH5 suggests their promising candidacy for detergent formulation. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Using GIS and remote sensing to map suitable sites for wind farms: a case study of Nkonkobe Municipality, Eastern Cape.
- Authors: Gwena, Jay
- Date: 2015
- Subjects: Geographic information systems http://id.loc.gov/authorities/subjects/sh90001880 , Remote sensing http://id.loc.gov/authorities/subjects/sh85112798 , Renewable energy sources http://id.loc.gov/authorities/subjects/sh85112837
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19420 , vital:43082
- Description: Issues relating to energy use, renewable energy introduction and climate change have received a lot of attention from governments throughout the world in the past two decades. Many developing nations like South Africa heavily rely on coal and other non-renewable resources for their production of energy. The processing of the non-renewable resources into secondary energy forms is according to many energy experts a chief contributor to climate change. Climate change is affecting agricultural production in many developing countries that entirely rely on rainfall for their production. The loss in production in South Africa is increasing the level of poverty in low-income earners and unemployed people. Also a lot of households found in rural areas of South Africa have no access to electricity. Electricity in South Africa is generated and distributed by Eskom a state owned company. In April 2008 Eskom failed to meet power demand and started introducing load shedding to maintain and upgrade their power plants. The load shedding stopped for while and was introduced again in 2014 when the power utility faced the challenge of failing to produce power to meet demand again due to problems with their power stations. The ongoing energy provision problems in South Africa can be alleviated by introducing alternative sources like renewable energy. Introduction of renewable energy in poorly developed areas like Nkonkobe Municipality can help households‘ access electricity and reduce load on the national grid. The aim of this study was to locate suitable sites for setting up wind farms in Nkonkobe municipality in South Africa. Wind energy as a resource is abundant in many areas of South Africa and areas to set wind farms for optimum harness of wind power were identified using GIS, remote sensing and multi-criteria decision making techniques. Wind speed, distance from settlements, distance from main roads, distance from national, slope and land use/land cover were chosen as the factors to consider in selecting a suitable site. Data was collected from South Africa Weather Services, University of Fort Hare and online free data sources. Thematic maps for all the factors were developed in ArcGIS and fed into Nkonkobe Municipality database developed for the study. Thematic maps were assigned weights before being overlaid using weighted overlay tool. Weights for the factors were determined using Analytical hierarchy Process‘ pairwise comparison approach. Weighted overlay of the thematic maps produced a map showing suitable areas based on the weight influence of each factor. The output map was compared to results obtained from using Boolean approach and weighted sum method as a way of checking the accuracy of obtained suitable sites. Results showed there are three sites that can be used for setting up wind farms in the study area. , Thesis (MSc) (Applied Remote Sensing and GIS) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
Using GIS and Remote Sensing to identify water-stressed areas in South Africa - A case study of the Raymond Mhlaba Local Municipality, Eastern Cape Province
- Authors: Malunda, Kasongo Benjamin
- Date: 2019
- Subjects: Water-supply Droughts
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17238 , vital:40868
- Description: The main purpose of this study is to identify water stressed areas as a response to climate variability (Drought), Aridity, and water exploitation in the Raymond Mhlaba Local Municipality (RMLM) using Geographical Information Systems (GIS) and Remote Sensing (RS). This study focused on evaluating whether it is best to address the issue of drought and water stress as a municipal problem instead of a community-based problem. To achieve this, the study was attempting to establish four things: the climate condition of the municipality, whether the municipality is a drought prone area, how the surface water is being exploited in the municipality, and identify areas that should be considered water stressed areas. There are several indices used to compute water stress and the study opted for indices that can monitor climate variability, and surface water resources. Therefore, the de Martone Aridity Index (MA) was used to compute the aridity of the municipality the Standardized Precipitation Evapotranspiration Index (SPEI) to compute drought, and the Water Exploitation Index (WEI) to measure population water exploitation. Data used was from 25 weather stations provided by the Meteoblue website and water data from the department of water and sanitation. Thereafter, the Analytical Hierarchy Process (AHP) was used to determine the weights of each variables’ contribution to water stress. For validation, the Shapiro, Jarqua Bera and Kolmogorov-Smirnov tests were used and results showed that the data was normally distributed and a two-sample t-test confirmed that there was no significant difference between the measured and simulated data. According to the de Martonne there are three main climatic regions in the Raymond Mhlaba Municipality namely: the Mediterranean, semi-humid and humid region. The Mediterranean region is equally prone to drought as the humid region while the semi-humid region was a wet prone. This was contradictory to literature that expected drier regions to experience more frequent drought. However, this may have been influenced by the number of weather points that cover the humid region that is far lower than the ones covering the Mediterranean region. In addition, the municipality is 50% drought prone and would experience extreme events about 30% of the time. The study discovered that towns such as Fort Beaufort, Alice, Adelaide, and Middle drift are water stressed areas. While most of the other regions are low water users. These challenges with water stress could be reduced with the implementation of water saving mechanisms such as water tanks and the avoidance of addressing water stress as municipal challenges as opposed to a town specific challenge.
- Full Text:
- Date Issued: 2019
Using data mining techniques for the prediction of student dropouts from university science programs
- Authors: Vambe, William Tichaona
- Date: 2016
- Subjects: Data mining Dropout behavior, Prediction of
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12314 , vital:39252
- Description: Data Mining has taken a center stage in education for addressing student dropout challenges as it has become one of the major threat affecting Higher Educational Institutes (HEIs). Being able to predict students who are likely to dropout helps the university to assist those facing challenges early. This will results in producing more graduates with the intellectual capital who will provide skills in the industries, hence addressing the major challenge of skill shortage being faced in South Africa. Studies and researches as purported in literature have been done to address this major threat of dropout challenge by using the theoretical approach which banked on Tinto’s model, followed by the traditional and statistical approach. However, the two lacked accuracy and the automation aspect which makes them difficult and time-consuming to use as they require to be tested periodically for them to be validated. Recently data mining has become a vital tool for predicting non-linear phenomenon including where there is missing data and bringing about accuracy and automation aspect. Data mining usefulness and reliability assessment in education made it possible to be used for prediction by different researchers. As such this research used data mining approach that integrates classification and prediction techniques to analyze student academic data at the University of Fort Hare to create a model for student dropout using preentry data and university academic performance of each student. Following Knowledge Discovery from Database (KDD) framework, data for the students enrolled in the Bachelor of Science programs between 2003 and 2014 was selected. It went through preprocessing and transformation as to deal with the missing data and noise data. Classification algorithms were then used for student characterization. Decision trees (J48) which are found in Weka software were used to build the model for data mining and prediction. The reason for choosing decision trees was it’s ability to deal with textual, nominal and numeric data as was the case with our input data and because they have good precision.The model was then trained using a train data set, validated and evaluated with another data set. Experimental results demonstrations that data mining is useful in predicting students who have chances to drop out. A critical analysis of correctly classifying instances, the confusion matrix and ROC area shows that the model can correctly classify and predict those who are likely to dropout. The model accuracy was 66percent which is a good percentage as supported in literature which means the results produced can be reliably used for assessment and make strategic decisions. Furthermore, the model took a matter of seconds to compute the results when supplied with 400 instances which prove that it is effective and efficient. Grounding our conclusion from these experimental results, this research proved that Data Mining is useful for bringing about automation, accuracy in prediction of student dropouts and the results can be reliably depended on for decision making by faculty managers who are the decision makers.
- Full Text:
- Date Issued: 2016
Understanding the links between smallholder farmers and retailers of meat and vegetables in Mthatha, Mqanduli, Port St Johns and Tsolo, Eastern Cape, South Africa
- Authors: Qaula, Nyaniso
- Date: 2020
- Subjects: Farms, Small
- Language: English
- Type: Thesis , Masters , M Agric
- Identifier: http://hdl.handle.net/10353/18823 , vital:42811
- Description: It is commonly accepted that one of the challenges faced by smallholder farmers is lack of ‘access to markets’. This is especially so against the backdrop of the supermarket revolution, which is widely understood to give advantage to large-scale farmers at the expense of smallholder farmers. Given that supermarkets are now well established even within South Africa’s former homelands, it would seem that even smallholders based in these areas are at a disadvantage. The purpose of this study is to delve deeply into the market access of smallholder farmers, and to do so specifically across a large area of the former Transkei where supermarkets are well established and where there are also a range of other types of retailers. The study seeks to understand the links between smallholder farmers and diverse kinds of food retailers of meat and vegetables in and around the towns of Mthatha, Mqanduli, Port St Johns and Tsolo in the Eastern Cape Province, South Africa. For each of these sites, the study estimates the share of purchased fresh vegetables and meat that ultimately originates from smallholder farmers within the former Transkei, as opposed to large-scale farmers further afield. The findings suggest that smallholder farmers account for about 24% to 40% of fresh vegetables, and 3% to 13% of meat. The difference between vegetables and meat seems to relate to the fact that smallholder farmers account for a reasonably large share of the fresh vegetables sold by at least some supermarkets, whereas smallholder livestock farmers are largely unable to sell to abattoirs, whether because of the standards imposed by these abattoirs (including the one in Mthatha), or because of the cost of transport. The differences between sites appear to be a function of several factors, including differential market size and resource endowments. The study further sought to identify the advantages and disadvantages that the different types of retailers experience in procuring from smallholder farmers, and also identify the advantages and disadvantages that smallholder farmers experience in supplying different types of retailers. The advantage of working with smallholder farmers is that smallholder farmers can even deliver on Sundays, unlike other suppliers that refuse to work during weekends. The disadvantage is that smallholder farmers are not producing consistently therefore it is hard to rely on smallholder farmers for supply of produce. The advantage that smallholder farmers experience in supplying different types of retailers is that they get their cash right away after delivering the produce. The challenge that smallholder farmers experience when supplying food retailers is that some of the supermarkets will see the sample and order large quantity, however on the day of delivery they will complain and say it is not the good quality so the farmers must reduce the selling price. The study suggests the strategy that could be used by farmers to access the market, which is to enhance knowledge of market skills and negotiation skills.
- Full Text:
- Date Issued: 2020
Understanding the contribution of Land Use/Cover (LUC) classes on soil erosion and sedimentation using sediment fingerprinting technique and RUSLE in a GIS interface at sub-catchment level
- Authors: Taeni, Thembalethu (https://orcid.org/ 0000-0001-7662-8652)
- Date: 2021-04
- Subjects: Geographic information systems , Soil erosion , River sediments
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20920 , vital:46747
- Description: Soil erosion by water is the major source of soil degradation in the world, and South Africa (SA) is not an exception particularly in the Free State (FS) Province. In South Africa, the Caledon River Catchment in the FS Province has been identified as one of the regions where soil erosion has been prevalent for decades. Evidence across many parts of the catchment show a widespread of soil erosion and the contaminant flux associated with sediment into river systems and reservoirs; including the Welbedatcht dam and Carthcart-drift dam in Ladybrand. It is of these issues that the current work aimed at enhancing the understanding of sediment sources and soil erosion dynamics at the Caledon River Basin. The objectives of the study were to locate sources of suspended sediments and to assess and quantify the contribution of Land Use Cover (LUC) classes to water erosion and sediment yield at a sub – catchment level of the Caledon River Basin. To achieve the objectives set out for this research, a study was conducted at a sub - catchment level of the Caledon River Basin in the FS Province, South Africa. The sediment–fingerprinting approach and the Revised Universal Soil Loss Equation (RUSLE) model were used in the study under Geographic Information System (GIS) settings. A qualitative and quantitative interpretation of the geochemical data were used to evaluate the potential for distinguishing catchment sediment sources. The application of multivariate sediment mixing models incorporating Monte Carlo simulations was undertaken to investigate recent variations in sediment sources. Lastly, to document the impact of LUC change on soil erosion; data from soil profile database, Landsat 8 OLI–TIRS and climate (i.e. rainfall) were used to assess and map the spatial and temporal pattern changes of soil erosion at a sub – catchment level as related to LUC changes. In this study, the sub–catchment was classified into 6 LUC classes. Thereafter soil erosion was quantified for three consecutive years namely; 2015, 2016 and 2018 using the soil erosion factors as GIS–layers. The investigation of sediment source types and spatial provenance in the catchment showed that the grassland areas have consistently been the main sediment source (83 percent) throughout the study period. Findings further showed that there was an increase in contributions from cultivation and abandoned cultivated fields. Sediment contribution from surface sources was dominant (54 percent) and thereafter, subsurface sediment input increased (62 percent). This trend is indicative of increased severity of gully erosion in the area and thus is consistent with other studies. To comprehend the influence of LUC class modification dynamics on soil erosion, water erosion in particular at the sub-catchment commencing from 2015 to 2018 (4 years), multi-temporal Landsat 8 information jointly with the RUSLE model were used. A post-classification, LUC class alteration comparison revealed that water bodies, shrubs and forested region and grassland declined by 0.27 percent, 15.60 percent, and 37.60 percent, respectively. On the other hand, regions under Bad lands, and bare-soil and built-up regions including agricultural region expanded by 2.22 percent, 5.78 percent, and 45.67 percent respectively, between 2015 to 2018 study period. The average yearly soil loss decreased at the sub-catchment and was 10.23,5.71 and 5.82 t ⋅ ha -1 ⋅ yr-1 for 2015, 2016 and 2018 respectively. Although soil loss lessened for the duration of the perceived period, a closer scrutiny revealed that there were nonetheless seeming signs of persistent escalation in soil loss risk. These signs were mostly shown in the elevated parts of the sub-catchment as shown by the red regions on the soil loss map. Additional examination of soil loss findings by LUC classes categories further indicated that most LUC classes categories, including Bare-soil and built-up area, agricultural-land, grassland, and region under shrubs and forests, showed increased soil loss levels during the 4 years’ study period at the sub-catchment. The information on the comparative vividness of diverse sediment sources given by the study must be observed as a noteworthy development towards an understanding of the sediment source dynamics in agricultural river based catchments; more so of the Caledon River Basin. Further research is recommended for other erosion prone catchments in South Africa to identify additional evidence of the spatial and temporal variations in soil erosion and sediment sources. The results of the study suggest that the procedure of assimilating the GIS and RS with the RUSLE model is not just precise, time-efficient and exact in recognizing soil erosion susceptible regions in geospatial and temporal standings. However, it is a cost-efficient substitute to standard field-founded approaches. , Thesis (MSc) (Soil Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
Two uses of DNA sequence variation in tracing evolutionary processes in Old World primates (Primates: Catarrhini)
- Authors: Dosi, Banele
- Date: 2016
- Subjects: Primates -- Evolution Monkeys Cercopithecidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8022 , vital:31464
- Description: Primate evolution is particularly interesting to humans, because it includes our own history. Molecular genetics is by far the most dynamic field in contemporary biology, and offers a host of new techniques for investigating evolutionary processes and patterns. In the mid-twentieth century molecular genetics evolved from being a means of visualising hidden variation (e.g. allozymes) to tracing phylogenetic relationships between and among species (evolutionary histories of populations), and now has a wide variety of applications in medicine, species identification and relationships, and even wildlife forensics. For my Master’s project I investigated two applications of molecular genetic analysis to questions regarding the evolution of Old World monkeys (Catarrhini). First, I participated in a study designed to test the hypothesis that different primate social structures – particularly mating systems – may be reflected in the structure of a species genome. We investigated whether increased sperm production as a result of sexual selection increases the number of copy number variations (CNVs) that can be detected by comparing the male specific region Y (MSY) located on the Y chromosome in a sample of primate species. We did not find a clear differentiation between the primate species as hypothesised, which thus requires a more complex explanation, e.g. in terms of the type of environment rather than the mating system of the species, or possibly the active/inactive status of the genes. The second part of my study was phylogeographic in approach. I collaborated with researchers studying the distribution of Afromontane samango monkeys (Cercopithecus albogularis labiatus) in the Eastern Cape. I sequenced tissues from 5 samango monkey specimens found opportunistically in the Hogsback and coastal forests and analysed their genetic variation relative to the data published by Dalton et al. 2015. The Hogsback sample was not monophyletic relative to the sample from the coastal forests, indicating that, on the basis of this very small sample size, these populations have not been separated historically. In order to validate this conclusion, I will need to investigate a larger sample size. From this study I developed valuable skills in the areas of the laboratory techniques involved in molecular sequence analysis, and an appreciation for the importance of large sample sizes in deriving reliable results. I intend to continue in the future with a phylogeographic study of samango monkeys.
- Full Text:
- Date Issued: 2016
Towards a reconstruction of Marion Island’s glacial history
- Authors: Rudolph, Elizabeth
- Date: 2020
- Subjects: Glacial landforms Geomorphological mapping
- Language: English
- Type: Thesis , Doctoral , PhD (Geography)
- Identifier: http://hdl.handle.net/10353/18531 , vital:42581
- Description: Southern Hemisphere glacial chronologies can provide valuable insights into interactions between glaciation and past climate changes. The sub-Antarctic Islands provide a valuable terrestrial record of glacial chronologies for the Southern Hemisphere, since they are unique, not only in size and topography, but also in oceanic situation when compared to other continental landmasses (e.g. Antarctica or Patagonia). On sub-Antarctic Marion Island, southern Indian Ocean, the exact timing and extent of the local Last Glacial Maximum is not yet known as glacial reconstructions have mostly been based on palynological proxies and relative-age dating techniques. This study presents 29 cosmogenic 36Cl exposure ages of deglaciated bedrock surfaces and moraine deposits from Marion Island. In addition, a comprehensive glacial-geomorphological map, which in conjunction with exposure ages provide improved temporal and spatial constraints for the island’s glacial history. Results show that the ice reached a local Last Glacial Maximum before 56 ka ago and retreated, with minor stillstands, until ~17 ka. This early deglaciation left island surfaces below 850 m a.s.l. ice-free after ~19 ka, and any subsequent advances during the Late Glacial or Holocene cooling periods would have been restricted to the interior. This glacial chronology is similar to that of some other sub-Antarctic Islands (e.g. the Kerguelen archipelago, Auckland and Campbell islands, and possibly South Georgia) and a number of other Southern Hemisphere glaciers (e.g. in Patagonia and New Zealand) and adds to evidence that suggest the Southern Hemisphere was in a glacial maximum earlier than the global LGM. A combination of climatic drivers such as declining temperatures, a northward migration of oceanic fronts and the Southern Hemisphere Westerly Winds (causing precipitation changes), as well as the physiography of Marion Island, created optimal conditions for glacier growth during Marine Isotope Stage 4 (MIS 4; ~65 ka ago) instead of the global LGM in MIS 2 (~18 ka). These findings redefine the glacial history of Marion Island, and have implications for future investigations on post-glacial landscape development and ecological succession.
- Full Text:
- Date Issued: 2020
Tillage and crop rotation effects on selected soil properties and wheat yield in a short term field experiment in the Eastern Cape province, South Africa
- Authors: Mtyobile, Mxolisi
- Date: 2017
- Subjects: Crop rotation -- South Africa -- Eastern Cape Cropping systems -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13414 , vital:39659
- Description: Severe land degradation associated with current conventional production systems have resulted in low production amongst the small scale farmers in the Eastern Cape. Inappropriate management practices cause depletion of organic matter and other essential nutrients leading to a decline in crop productivity. There is growing evidence that conservation agriculture (CA) practices involving no-tillage (NT) coupled with crop rotation and surface residue retention increases soil organic carbon (SOC) and other essential nutrients and therefore has potential to alleviate soil quality deterioration. A study was carried out to investigate the effects of tillage and crop rotation with crop residue retention on selected soil properties and on wheat yield in the Alice Jozini ecotope of the Eastern Cape. Specific objectives were to determine (i) the effect of crop rotation and tillage on soil SOC, NH4, NO3, total N, P, K, Ca, Mg, Zn, soil pH and EC distribution at 0-5 cm, 5 cm -10 cm, 10 cm-20 cm (ii) the effect of crop rotation and tillage on soil bulk density, porosity and on soil water content (iii) the effect of crop rotation and tillage on wheat biomass and grain yield. Treatments were arranged as a split-split plot in a randomized complete block design with three replicates. Tillage treatments included no-tillage (NT) and conventional tillage (CT) and were applied on the main plots while crop rotation treatments were applied as subplots. Crop residue retention treatments were applied as sub-sub plots. The rotational treatments were maize-fallow-maize (MFM), maize-fallow-soybean (MFS), maize-wheat-maize (MWM) and maize-wheat-soybean (MWS). However, the current study focused on tillage and crop rotation treatments under residue retention to give 8 treatments. Data from the field trials showed that NT with residue retention had significantly (p < 0.05) higher SOC, Total N, P, K, Ca and EC relative to CT. The MWS rotation under no-tillage (NT) with residue retention followed by MFS resulted in the progressive improvement in soil nutrient status. The correlations of SOC with various soil nutrients under study showed that the nature of the relationships between SOC and nutrient availability was consistent. Results on soil physical parameters showed that tillage had no significant effect (p > 0.05) on soil bulk density (ρb) and porosity whereas a significant effect on soil water content under NT was observed. Crop rotation had no significant effects (p > 0.05) on soil bulk density, porosity and soil moisture across the tillage treatments. The MWS rotation registered an increase in soil porosity in comparison with the MWM and MFM. Tillage x crop rotation interaction effects were significant (p < 0.05) on the measured porosity and soil water content. Soil bulk density showed negative correlation with soil porosity and soil water content (SWC) whereas porosity had a positive correlation with SWC. On yield parameters, results revealed that no significant (P>0.05) interaction of main effects with respect to wheat biomass and grain yield. Tillage had a significant (P<0.05) effect on wheat biomass only in season 2. Tillage and crop rotation effects were not significant (P>0.05) with regards to grain yield throughout the experimental period. Higher grain wheat biomass and grain yield were found in MWS rotation under NT with surface residue retention although not statistically significant. Correlation analysis revealed that wheat yield was positively correlated to SOC, P, and Total N. Therefore, combination of NT with MWS rotation with residue retention has the potential to significantly improve soil chemical properties and wheat grain yield whereas MWM followed by MWS crop rotation under NT showed an increase in soil porosity and soil water content.
- Full Text:
- Date Issued: 2017
Threatened plant species in Vhembe Biosphere Reserve, Limpopo province, South Africa: Problems and prospects of conservation and utilization
- Authors: Ramarumo, Luambo Jeffrey https://orcid.org/0000-0002-2393-6982
- Date: 2022-03
- Subjects: Plants -- Extinction , Rare plants , Botany, Economic
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22754 , vital:52738
- Description: Threatened plant species are those species that are vulnerable or at the risk of extinction. According to Version 3.1 of the International Union for Conservation of Nature (IUCN)’s Red List Categories and Criteria, the three categories of threat in order of increasing risk of extinction are: Vulnerable (VU), Endangered (EN) and Critically Endangered (CR). These species are oftenly protected by both national and international obligations. Scientific evidence suggests that threatened plants are disappearing at an alarming rate. The current expansion of agricultural land, urbanization, over-exploitation of biological resources, climate change and invasive alien species are regarded as major drivers of biodiversity loss and high rate of species extinction worldwide. Scientists and conservation managers are seeking to understand and monitor plant species that are likely to be on the verge of extinction. Monitoring of threatened plants can be better achieved through insights about indigenous knowledge dynamics associated with such species. Scientific scholars including botanists, ethnobotanists, conservationists and anthropologists, all share common interest about the use of indigenous knowledge for livelihoods, scientific and economic growth. As a result, there is a growing interest on indigenous knowledge researches, particularly involving utilization and conservation of plant species. Given the fact that recent scientific evidence suggests that such studies are lacking in South African Biosphere Reserves, as well as the fact that scientist and conservation managers are seeking to understand species likely to be on the verge of extinction risk. It is within this context that this study is aimed at investigating threatened plant species utilization, conservation statuses and distribution in the Vhembe Biosphere Reserve, Limpopo Province in South Africa. The hypothesis of this study states that traditional knowledge about utilization, distribution and conservation statuses of threatened plant species provide suggestions for appropriate conservation practices. Since the current study is ethnobotanical in nature that is focusing on human interactions with plants, the research methods used addressed multidisciplinary aspects and involved disciplinary integration. An integrated participatory research approach focusing on shared learning, forging collaborative relations with participants, analyzing and validating the shared knowledge was used to document ethnobotanical data within the study area. This research approach was selected as it is considered to be a quick and effective way of acquiring data associated with indigenous knowledge systems. To offset the elements of bias during data collection, the research technique was designed to accommodate core principles that interlinked participatory rural appraisal (PRA) and rapid rural appraisal (RRA). Furthermore, the integrated core principles of participatory rural appraisal and rapid rural appraisal were used with conventional methods such as field surveys and interviews using questionnaires. Therefore, ethnobotanical data were collected through interviews with 203 participants. The data associated with threatened plant’s population size were gathered through literal counting of individual plants as per the IUCN’s Red List Criteria. Data associated with the conservation statuses were gathered from both the South African National Biodiversity Institute and IUCN databases. A total of 13 useful threatened plants belonging to 12 families were recorded with their conservation statuses ranging from being Vulnerable to Critically Endangered. The majority of the threatened plant species (46.0percent) were used for medicinal purposes only, followed by species used for medicinal purposes and as ornamentals (23.0percent). The frequently cited useful threatened species with use values (UV) > 0.024, relative frequency citation (RFC) > 0.059 and fidelity level percentage (FLpercent) > 5.911percent, included Asparagus sekukuniensis, Bowiea volubilis, Brackenridgea zanguebarica, Ocotea bullata, Rhynchosia vendae, Siphonochilus aethiopicus and Warburgia salutaris. About 47.0percent of the recorded useful threatened plants were distributed in remote areas of the Thathe Vonḓo and its surroundings. Threatened plants with population size < 100 adult individuals constituted the majority (61.54percent). Birdlime-making plant species were also documented in the current study. A total of 12 birdlime-making plants belonging to six families were recorded, including threatened Huernia nouhuysii, which is categorized as Vulnerable in South Africa. Amongst the recorded families, Loranthaceae and Euphorbiaceae were categorized as the most frequently utilized families. Among the recorded species, six of them were reported to being used in the birdlime-making for the first time and these species include Euphorbia pulvinata (17.2percent), followed by Tapinanthus forbesii (8percent), Tapinanthus rubromarginatus (7.2percent), Erianthemum ngamicum (7.2percent), Englerophytum magalismon-tanum (3.6percent), Huernia nouhuysii (2.0percent), and Euphorbia tirucalli (0.8percent). Only three plant parts were utilized for birdlime-making. The milky latex was preferred plant part (58.3percent), followed by fruit (33.3percent) and root bark (8.4percent). Birdlime-making techniques involved crushing, which accounted for 55.7percent, followed by air blown (29.6percent) and boiling (14.7percent). Furthermore, the complementary contribution of birdlime toward human development included, being used for bird hunting or trapping small birds (45.8percent), adhesion (23.2percent), teeth cleaning (17.2percent) and roof-waterproofing (13.8percent). The indigenous conservation strategies employed by participants included harvesting of single lateral root per individual medicinal plant (15.3percent), medicinal and timber materials are only harvested during winter season (16.7percent), the use of moist soil to cover injured plant part after bark harvest (18.2percent), prohibit harvesting of and/ or from an injured plant (11.8percent), collection of dried or fallen plants for firewood (8.4percent), issuing of permits by traditional council through the chief or headman to allow collection of medicinal materials and timber (9.9percent), prohibit chopping down of medicinal plant species (13.8percent) and collection of some Critically Endangered plant species such as Brackenridgea zanguebarica and Siphonochilus aethiopicus during the night by authorized people only (5.9percent). The hypothesis which stated that traditional knowledge about utilization, distribution and conservation statuses of threatened plant species provide suggestions for appropriate conservation practices can therefore, not be rejected as there is room for further and more detailed ethnobotanical investigations that is focused on human interactions with threatened plant species. The data presented in this thesis could be used as baseline information for formulating new conservation strategies, monitoring and management plans of threatened plant species not only in the Vhembe Biosphere Reserve, but in other regions of South African. This study provided insights associated with ethnomedicinal uses of Asparagus sekukuniensis, Protea laetans and Encephalartos hirsutus. Results of this study could also stimulate interest in other scientific disciplines such as the phytochemistry, pharmacology, bioprocessing, conservation and anthropology involving documentation threatened plant species. , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-03
Thermal studies on three common mangrove-associated ectotherms in Mngazana Estuary, with emphasis on the survival of the salt marsh crab, Parasesarma catenatum (Ortman 1897
- Authors: Nonyukela, Asandiswa Simamkele
- Date: 2020-02
- Subjects: Mangrove forests
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20838 , vital:46627
- Description: Ecological data on the development and distribution of mangroves over time suggest that mangroves were strictly tropical in nature but have extended to higher latitudes during warmer periods. Species distribution models show that the mangrove range may have since 1963 expand by 17 km in 2020 and by as much as 68 km southwards by 2050. More climate data obtained, and modelling of future climate have increased interest in the thermal tolerance or organisms. Critical thermal maxima (CTMax) and thermal tolerance were employed to determine the thermal limits of common estuarine species associated with the mangrove forests at Mngazana Estuary. Three species were selected, each representing a medium within the mangrove environment: for water, i) Palaemon peringueyi; ii) for air, Cerithidea decollata; and iii) Parasesarma catenatum on the substratum. Animals were acclimated for 48 hrs following the thermal history of the environment. Each individual was exposed to constant rate of water temperature increase of 1°C.h-1. Different size classes (adult, sub-adult, juveniles) of crabs were used to determine the CTMax performance. Parasesarma catenatum showed intraspecific variability in CTMax in both air and water. Palaemon Peringueyi had a CTMax value of 33.8°C±1.96 while C. decollata had a CTMax of 39.6°C±2.76 and P. catenatum had a CTMax of 36,38 ±1,57 in water and 34,1 ±1,67 in air. Different size classes (Adult, Sub-adult, Juveniles) of crabs were used to further determine their CTMax performance. Parasesarma catenatum showed of intraspecific variability in CTMax in both air and water. Juvenile crabs showed higher CTMax in water than in air, while adult and sub-adults showed a higher CTMax in air. The size classes of P. catenatum (Adult, Sub-adult, Juveniles) were exposed to a range of salinity treatments from 5-65 for both shock and acclimated exposures. For acclimated exposures, crabs were acclimated down/up at change of 5-10 untill the test salinity was reached, at which point the crabs were exposed. For the shock exposure, the crabs were directly exposed to the test salinity from the holding salinity of 35. This study shows P. catenatum is euryhaline, tolerating salinities been 10 and 50. Survival was highest across all cohorts for the short-term (shock) exposure, suggesting prolonged exposure to hypo/hypersaline conditions may be detrimental for this keystone Mngazana Estuary species. Juven.ile populations showed the highest survival rate for both shock and acclimated exposure. This study highlights the importance of microhabitat variability and its effect on the tolerance of different species to abiotic factors and so may be useful in modelling the effects of climate change in these systems. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-02
The use of information and communication technologies in agricultural development in rural areas: Case of smallholder farmers in Umzimvubu Local Municipality
- Authors: Makaula, Zimasa
- Date: 2020
- Subjects: Agricultural extension work -- Information technology Farms, Small -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Agric (Agric Extension)
- Identifier: http://hdl.handle.net/10353/11994 , vital:39125
- Description: Proper and timeous communication amongst different social development participants is one of the main driving factors for successful human progress. Different platforms have been used by different industries across the globe to ensure that useful information is shared with relevant structures at appropriate times. The global increase on use and availability of Information Communication Technologies (ICT’s) has prompted a thorough analysis and study of their relevance on different industries. Much of the increase has been observed mainly on highly urbanized areas, where the majority of the population is literate and who are above the poverty line. Some researchers have argued that the language used in some of the ICT’s is limited to the elite few, while others highlight cost implications in the use of these ICTs. The agricultural industry is not immune to the debates that relate to the development of ICTs, it is in most cases at the center, due to its diverse nature (in terms of participation) and close linkage to human development. There seems to be a correlation between ICT usage and the economies of scale in agricultural development, where smallholder farmers tend to use less of highly modernized ICTs, while commercial large scale farmers use more of the modernized ICTs. This disparity amongst farmers is exacerbated in many areas by the differing support systems employed by the public extension services. This study was initiated in order to study the usage and relevance of the ICTs by the smallholder farmers of the Umzimvubu Local Municipality of the Eastern Cape Province in South Africa. The research address the following research questions: 1. Which ICTs are owned by smallholder farmers of Umzimvubu local municipality? 2. Do smallholder farmers use ICTs to communicate agricultural information? 3. What are the types of ICT devices and services used by smallholder farmers for vi agricultural development? 4. What are the challenges faced by smallholder farmers when using ICTs to communicate agricultural information? A survey questionnaire was then developed to collect the relevant data from randomly selected six villages of Umzimvubu Local Municipality. The questionnaires structure employed both closed and open-ended questions that were administered using a face to face interview, conducted on the sample population in each village. The results indicated that the most common ICTs that were owned by smallholder farmers in the study area were: mobile phones (33%), televisions (TV) (28%), and radio (20%). The results also showed that communication amongst farmers (35%) and extension officers (35%) was the most notable use of mobile phone from the study area. The results also revealed that most smallholder farmers faced the following challenges when using ICTs to retrieve agricultural information; poor signal (40%), inconsistent broadcasting times for TV and radio agricultural programmes (35%), language barrier (15%) and lack of electricity (10%). The study, therefore, concludes that a majority of smallholder farmers from the study area own ICT devices necessary for rural agricultural development (mobile phones, TV and radio) that can be targeted by extension officers, policy makers, rural development implementing agencies and agro-industries to promote rural development. However, several challenges (language barrier, poor network signal and no electricity) limit the potential of these ICT devices and services from fully benefiting smallholder farmers.
- Full Text:
- Date Issued: 2020
The use of earth observation multi-sensor systems to monitor and model Pastures: a case of Savannah Grasslands in Hluvukani Village, Bushbuckridge Local Municipality, Mpumalanga Province, South Africa
- Authors: Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Date: 2022-01
- Subjects: Climatic changes , Grassland conservation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22578 , vital:52470
- Description: Grassland degradation associated with climate change and inappropriate grassland management has been characterized as a global environmental concern driving decreased grassland ecosystem's ecological functioning. More than 60% of South African grassland is degraded or permanently transformed to other land uses and nearly 2% properly conserved. Yet, grasslands are a major source of food for livestock grazing and provide material and non-material benefits to many livelihoods. Therefore, grassland above-ground biomass (AGB) estimation is crucial in planning and managing pastoral agriculture and the benefits derived from it. However, current grassland monitoring techniques used in rural smallholder livestock farms rely on conventional methods, which are destructive, labour-intensive, costly, and restricted to small areas. This study investigated the monitoring and modelling of protected grasslands biomass using current Earth observation systems (EOS), an approach, which is non-destructive, cost-effective, cover larger areas and is a time-saving alternative to conventional methods. Hence, the research objectives were: (i) to map the trends and advances in data and models used in the monitoring of grassland (pastures) with Earth observation systems, and (ii) to assess above-ground biomass estimation in semi-arid savannah grassland integrating Sentinel-1 and Sentinel-2 data with Machine-Learning. This goal was to assess if this approach could provide the requisite information, which could contribute to the long-term goal of developing a semi-automated system for data processing, and mapping grassland biomass to benefit local communities. For this investigation, it was crucial to understanding what research had achieved so far in this area of pasture management. An assessment of the Scopus database showed the recent developments in European Union (EU) programs and Sentinel missions, including statistical models and machine learning for monitoring grassland changes at multiple scales. However, Sentinel-1 and Sentinel-2 data, machine learning models, and variable importance techniques were applied for grassland AGB estimation. These techniques have been used in similar studies to determine optimum machine learning models, influential variables, and the capability of integrated Sentinel datasets for mapping grassland AGB, spatial distribution, and abundance. Results showed improved performance with the Random forest regression (RFR) model (R² of 34.7%, RMSE of 9.47 Mg and MAE of 7.68 Mg ). The study also observed optimum sensitivity of Difference Vegetation Index (DVI) and Enhanced Vegetation Index (EVI) in all three machine learning models for modelling grassland AGB estimation in the study area. A further, statistical comparison of all three machine learning models showed an insignificant difference in the predictive capacity for AGB in the study area with Gradient Boosting regression (GBR) model (R² of 27.7, RMSE of 9.97 Mg and MAE of 8.03 Mg ) and Extreme Gradient Boost Regression (XGBR) model (R² of 17.3%, RMSE of 10.66 Mg and MAE of 8.83 Mg ). The study revealed that an integration of Sentinel-1 and Sentinel-2 has improved capabilities for monitoring grassland AGB estimation. This research sheds light on the timely and cost-effective techniques for grassland management strategies to enhance or restore the ecological functioning of grassland ecosystems and promote community sustainability. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-01
The use of behaviour, saliva cortisol and faecal glucocorticoid levels as stress indicators in beef cows
- Authors: Dzviti, Melody
- Date: 2017
- Subjects: Veterinary physiology Beef cattle -- Behavior Glucocorticoids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8165 , vital:31634
- Description: The study evaluated the use of saliva as a minimally invasive technique for cortisol level determination. This was done by assessing the relationship between serum and saliva cortisol based on short sampling intervals. In addition, the study also determined the effect of successive handling on faecal glucocorticoid metabolites (FGM), rectal temperature (RT), avoidance distance (AD), chute and crush scores as well as urination, defaecation and vocalization in multiparous cows. For trial one six non-pregnant, clinically healthy Nguni cows were used. They were administered with standardised doses of adrenocorticotropic hormone on treatment days and saline was used as a placebo on alternative days. Simultaneously, blood and saliva samples were collected to quantify cortisol levels. No relationship (r = 0.0131, P>0.05) was observed between serum and saliva cortisol. However, results showed that there was adrenal stimulation in saliva coupled by significant (P<0.05) effects of sampling intervals. For the second study 21 non-pregnant and clinically healthy Nguni cows of one herd were used for the trial. They were divided into parity groups and their weights were used as a covariate in data analysis. For five consecutive weeks, fresh faecal samples were extracted and rectal temperatures measured. In addition, fear of approaching humans was assessed by AD scores and behaviour scores in the crush chute, as well as vocalisation, urination and defaecation were observed. The effect of successive handling significantly (P<0.05) affected the physiological parameters, namely FGM and RT. Contrariwise, Chi-square tests revealed that parities had a significant (χ2 < 0.05) influence on AD and crush scores as well as on the occurrence of excretory behaviour. It was concluded that saliva cortisol can be used as a stress indicator in beef cows. However, plasma cortisol can be significantly volatile thereby becoming less sensitive to changes across time. This can cause a lack of relationship between plasma and saliva cortisol. On the other hand, repetitive handling of beef cows has an influence on faecal stress levels. In addition, beef cows of differing parities behave differently to handling stress.
- Full Text:
- Date Issued: 2017