The advent of grid electrification in the Sandveld region of South Africa in the 1980s increased the utilisation of groundwater resources for commercial irrigation purposes. In the wake of the consequent increased pressure on the resource, it behooves landowners to use water more productively and responsibly. This paper calculated the marginal product value (MPV) of irrigation water for potatoes and vine production in this region to assess and to allow the comparison of the productivity of irrigation water with other commodities and regions.
To establish the significance of Henry Bernstein's theoretical work on the dynamics of agrarian class struggles in Africa, this paper discusses two important political debates in which he has been both observer and participant, and that have oriented much of the subsequent Marxist work done in Africa on agrarian change. The first was the heated discussion begun over 40âyears ago around Nyerere's âAfrican socialismâ and the failures of the ujamaa policy of villagization. The second is the still unsettled debate around programmes of redistributive land reform in South Africa.
The acceleration of soil erosion by water in most regions of the world in response to the anthropogenic modification of landscapes is a serious threat to natural ecosystem functionalities because of the loss of invaluable constituents such as soil particles and organic carbon (OC). While soil OC erosion is likely to be a major component of the global C cycle, water erosion-induced CO₂ emissions remain uncertain. In this study, our main objective was to compare the release of CO₂ from eroded topsoils and from the sediments exported by diffuse erosion during an entire rainy season.
The Okavango catchment in southern Africa is subject to environmental as well as socio‐economic transformation processes such as population growth and climate change. The degradation of soil and vegetation by deforestation and overgrazing is one of the downsides of this development, reducing the capacity of the land to provide ecosystem functions and services. In this study, climate simulations are brought together with secondary socioeconomic, pedologic and remote‐sensing data in a GIS‐based assessment of the factors commonly associated with land degradation risk.
The origins and development of severe forms of erosion are traced in the communal villages located in a part of the dividing ridge between the Great Fish and Keiskamma rivers near Peddie town, Eastern Cape, South Africa. Progressive changes in land use and soil erosion distribution are reconstructed by analysing sequential aerial photographs of the area between 1938 and 1988. The distributions of the two phenomena are mapped and quantified at the different dates using PC ARC/INFO GIS. Observable soil erosion is confined to the communal lands at all the dates.
There is an extraordinary assortment of technical approaches to conserving carnivore populations, but the effectiveness of conservation activities is rarely evaluated. Accordingly, we initiated a study to assess the impact of several conservation interventions on the dynamics and persistence of a leopard (Panthera pardus) population in Phinda Private Game Reserve, South Africa. These included revisions of the statutory systems that regulate problem animal control and trophy hunting, and we instituted a program intended to reduce human-leopard conflict in the region.
Temporarily open/closed estuaries in South Africa are being subjected to varying degrees of catchment land-cover transformation. Natural landscapes and hydrological functions are integral to the functioning of estuaries. The relationship between catchment land-cover and the health of the East Kleinemonde Estuary was investigated between 2011 and 2013, using geographic information system (GIS) techniques to delineate and quantify land-cover in the whole catchment, in the lower section of the catchment, and in the 1 km and 100 m buffer zones surrounding the estuary.
Meat production in South Africa is on an increasing trend. In South Africa rising wealth, urbanisation and a growing middle class means South Africans are eating more processed and high-protein foods, especially meat and dairy products. These foods are more land- and water-intensive than fruit, vegetable and grain crops, and further stress existing resources. Traditional agricultural farms cannot keep up with the increasing demand for animal products and these farms are being replaced with concentrated animal feeding operations.
Provision of clean freshwater is an essential ecosystem service that is under increasing pressure worldwide from a variety of conflicting demands. Water yields differ in relation to landâcover type. Successful resource management therefore requires accurate information on yields from alternative vegetation types to adequately address concerns regarding water production. Of particular importance are upper watersheds/catchments, regardless of where water is extracted.
Evidence is accumulating of a general increase in woody cover of many savanna regions of the world. Little is known about the consequences of this widespread and fundamental ecosystem structural shift on biodiversity. South Africa. We assessed the potential response of bird species to shrub encroachment in a South African savanna by censusing bird species in five habitats along a gradient of increasing shrub cover, from grassland/open woodland to shrubland dominated by various shrub species.