36 research outputs found
A Primer on Savanna Ecology.
An IES Special Report.Savanna is one of the world's major biomes (Figure 1). It occupies 54% of southern Africa, 60% of sub-Saharan Africa and 20% of the global land surface (Scholes and Walker, 1993). Furthermore, a large proportion of the world's human population and the majority of range-lands and livestock are found in savannas (Werner, Walker and Stott, 1991).
Savannas contribute to both the informal and formal economies of many countries (Campbell, 1996). They supply grazing, fuel-wood, timber and other resources to the informal and subsistence economy. Savannas also contribute to the formal economy because they are the main location of the livestock and eco-tourism industries. Globally, savannas are important because of emissions of trace gases from fires, soils and animals (Justice, Scholes and Frost, 1994); sequestration of carbon in their soils and biomass; and their biological diversity.
Savannas are, however, experiencing increasing pressures from demographic and economic changes that have increased dramatically over the past few decades. Severe damage to vegetation and soils is evident in. several regions (Werner, Walker and Stott, 1991). A further threat to the structure and functioning of savannas is the forecast of global warming and likely changes in precipitation pattems.Funded by the Canadian International Development Agency (CIDA) of Canada. AFSA is a University Partnership in Co-operation and Development Project (UPCD) managed by the Association of Universities and Colleges of Canada (AUCC)
The relationship between learning styles and perceptions of blended learning : a case study of third-year Environmental Science students at Rhodes University
The use of blended learning to support teaching and learning is growing globally. Few studies, however, have investigated the relation between students’ learning styles and their perceptions of blended learning. This study used a case-study approach to investigate third year Environmental Science students’ learning styles and perceptions of the online component of blended learning at Rhodes University. Vermunt’s inventory of learning’s styles instrument was used to assess the students’ learning styles. Students’ perceptions of online learning were assessed using an 84-item online experience questionnaire. Multivariate cluster analyses based on students’ learning styles, perceptions of online learning and final coursework marks were done. The correlation between learning styles and perceptions of blended learning was assessed. Students had been using computers for about 10 years. About 91% of students owned computers and 50% had access to Internet at home or in their residences. Internet and email were the most commonly used tools for student learning averaging about at least six times per week. Three of Vermunt’s four learning styles were identified. These were the meaning-directed, application-directed and reproduction-directed styles. The undirected learning style was absent. A major finding of this study was the dissonance in learning styles of students. For example, students with the meaning-directed style also scored high on reproduction-directed style. Students combined deep approaches with memorisation when learning. I developed an instrument consisting of seven scales that described students’ perceptions of online learning. The scales were epistemological judgements, multiple sources of information, learning goals, relevance, Internet experience, appropriate tool and student interaction. There was high within scale variability in students’ perceptions of online learning. The perception that the Internet provided multiple sources of information was positively associated with advanced models of epistemology that support the construction of knowledge. There was dissonance between the perception of the Internet as enhancing epistemological judgements and some components of learning style. A perception of epistemological judgements was positively correlated with both deep and surface cognitive processing strategies
Fire behaviour in a semi-arid Baikiaea plurijuga savanna woodland on Kalahari sands in western Zimbabwe
Human-induced fires are a major disturbance in Baikiaea plurijuga woodland savannas that are economically important for timber production. Most fires occur during the late dry season, when they may severely damage woody plants. Prescribed burning during the early dry season is a management strategy to reduce fuel loads and thus the incidence of intense fires during the late dry season. There is, however, little information on fire behaviour characteristics of early dry season fires.We studied the relationship between experimental fuel conditions and fire behaviour by lighting 15 fires during the early dry season in a Baikiaea woodland. Fire intensity ranged from 25 to 1341 kW m[superscript (-1)], while rate of spread of fire varied between 0.01 and 0.35ms[superscript (-1)]. Fire intensity and rate of spread were positively related to flame height, leaf-scorch height and proportion of the area burnt. The relationships suggest that fire characteristics can be retrospectively determined using a variable such as scorch height. The grass fuel load, wind speed, relative humidity and to a lesser extent fuel moisture were important predictors of rate of spread, flame height, leaf-scorch height and proportion of the area burnt, with no impact due to the litter fuel load. The grass fuel load and wind speed had a positive effect on rate of spread, whereas relative humidity and fuel moisture had a negative effect. These findings indicate that managers can predict the likely damage to woody plants during an early dry season burn by assessing the grass fuel load and weather conditions at the time of burning
Assessing the effects of invasive alien species on rural livelihoods: Case examples and a framework from South Africa
The detrimental impacts of invasive alien species (IAS) on ecosystem goods and services and local and regional economies are well documented. However, the use of IAS by rural communities is little understood, and rarely factored into IAS control programmes. Understanding the use of IAS by rural communities and factoring these into cost-benefit models is complex, depending upon a range of local-level attributes such as the time since invasion, abundance, and local-level costs and benefits. This paper reports on two case studies examining the role of IAS in rural livelihoods in the Eastern Cape, South Africa. In both cases, rural communities made widespread consumptive use of the IAS and generally would prefer higher densities, except in certain key localities. Several households traded in IAS products to generate supplementary income. We present a conceptual framework to guide interpretation of these and future case studies, considering attributes such as time since invasion, the competitiveness of the species, and the relative costs and benefits
Urban fuelwood demand and markets in a small town in South Africa: Livelihood vulnerability and alien plant control
Fuelwood is the primary energy for most households throughout the developing world. With increasing urbanization and declining local availability of fuelwood, a growing proportion of households obtain their fuelwood by purchasing it. These fuelwood markets are the key nexus in supply and demand scenarios and can be potentially significant points for intervention to address energy security amongst the urban poor. This paper reports on the fuelwood demand and marketing in a small town in South Africa. Despite the availability of more modern fuels and state subsidization of electricity, fuelwood was still used by half the households. Annual demand was 1.2 t per household. Over half of the households bought their fuelwood requirements because local stocks were limited. Those households that did collect their own fuelwood were significantly poorer than households that purchased fuelwood, as well as households that did not use fuelwood at all. Fuelwood markets operated through 45-60 vendors who transported fuelwood from further afield. Income from the fuelwood trade was low, but was strongly linked to hours worked. Thus, vendors working a full week did earn a meaningful income, especially in the context of high unemployment in the area. Fuelwood vendors also provided casual employment opportunities for unskilled labour. Most vendors harvested fuelwood from commonage lands, with most of the wood being from alien species. Local stocks of wood are declining in the face of constant transformation of commonage to residential areas, and a national water and biodiversity conservation programme to eradicate alien plants. This decline poses a threat to the financial viability of fuelwood markets. Yet, an opportunity exists to incorporate the vendors into the alien plant clearing programme, since they already perform such a function
Deagrarianisation and forest revegetation in a biodiversity hotspot on the Wild Coast, South Africa
Deagraianisation is a worldwide phenomenon with widespread social, ecological and economic effects yet with little consensus on the local or higher level causes. There have been contested views on the causes and consequences of deagrarianisation on South Africa’s Wild Coast, which is an international biodiversity hotspot. Using GIS, household interviews and ecological sampling, we compared the perspectives of current and former cultivators as to why some have abandoned farming, whilst also tracking the uses and woody plant cover and composition of fields abandoned at different periods. The GIS analysis showed that field abandonment had been ongoing over several decades, with a decline from 12.5 % field cover in 1961 to 2.7 % in 2009. The area of forests and woodlands almost doubled in the corresponding period. There was a distinct peak in field abandonment during the time of political transition at the national level in the early 1990s. This political change led to a decrease in government support for livestock farming, which in turn resulted in reduced animal draught power at the household and community level, and hence reduced cropping. The study showed it is largely the wealthier households that have remained in arable agriculture and that the poorer households have abandoned farming. The abandoned fields show a distinct trend of increasing woody biomass and species richness with length of time since abandonment, with approximately three woody plant species added per decade. Most local respondents dislike the increases in forest and woodland extent and density because of anxiety about wild animals causing harm to crops and even humans, and the loss of an agricultural identity to livelihoods and the landscape
Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.
BACKGROUND: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. METHODS: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. FINDINGS: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. INTERPRETATION: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. FUNDING: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.The SHINE trial is funded by the Bill & Melinda Gates Foundation (OPP1021542 and OPP113707); UK Department for International Development; Wellcome Trust, UK (093768/Z/10/Z, 108065/Z/15/Z and 203905/Z/16/Z); Swiss Agency for Development and Cooperation; US National Institutes of Health (2R01HD060338-06); and UNICEF (PCA-2017-0002)
Permaculture: Challenges and Benefits in Improving Rural Livelihoods in South Africa and Zimbabwe
Feeding a growing global population using conventional agricultural practices is leading to adverse environmental impacts. There is a call for alternative forms of agriculture that address social, economic, and environmental aspects of sustainability. Permaculture is a holistic design framework that incorporates sustainable agricultural practices, potentially improving livelihoods. This study looked at the challenges and benefits of permaculture in improving rural livelihoods in Zimbabwe and South Africa. We used semi-structured interviews to collect data. Permaculture contributed over 40% to total income for participants in both countries. However, permaculture was not the dominant source of income and periodically straddled multiple livelihood strategies. The main benefits of permaculture were identified as improved human health, increased resilience to environmental changes, and reduction of input costs. The key challenges included high labour input, infestation of pests and diseases, and lack of knowledge on permaculture practices. Although permaculture presents significant challenges, its integration with other forms of sustainable agricultural practices can contribute to improved rural livelihoods
Fire use practices, knowledge and perceptions in a West African savanna parkland.
Understanding people's practices, knowledge and perceptions of the use of fire and fire regimes can inform fire management plans that could contribute to savanna conservation and sustainable management. We investigated the frequency of fire use, control and perceptions of fire regimes for selected livelihood and socio-cultural activities in six districts in the Guinea savanna of Ghana. The six districts were selected to have a good representation of fire prone areas in the region based on fire frequency data obtained from the CSIR Meraka Institute, South Africa. A multiple regression analysis showed that people's use of fire for the selected socio-cultural activities from district, occupation, gender, age and ethnic group significantly predicted fire use for the activities R2 = 0.043, F (5,498) = 5.43, p < 0.000. Age and occupation added significantly to the use of fire. The study revealed that the majority of respondents (83%) across the study districts used fire once a year for at least one of the following activities: land preparation, weed/pest control, burning postharvest stubble, bush clearing around homesteads, firebreaks, charcoal burning and hunting. The study also showed a higher frequency of fire use for land preparation for cropping than for the other activities. Less than a fifth of the respondents (17%) indicated that they do not use fire for any of the selected activities. The majority of respondents (65%) mentioned that they controlled their use of fire to prevent destruction to property or injuring humans. The study revealed a higher frequency of fire use in the dry season for land preparation for cropping. However, respondents rated season of burning as the most important attribute, with little attention to the other attributes of a fire regime, contrary to what is theoretically recognized. Understanding traditional fire use practices in terms of how to regulate the mix of frequency, intensity/severity, season, size and type of fire for these and other socio-cultural purposes could help to mitigate and/or manage bushfires in West African savannas and enhance savanna conservation and management. Hence, the need to better understand people's knowledge and perceptions of fire regimes in fire assisted socio-cultural practices in West Africa
Veld Rehabilitation: AGP 421
Veld Rehabilitation: AGP 421, degree examination November 2010