Land degradation is a significant issue in South Africa (see Figure 1 and Figure 2) with 60% of the land currently degraded (UNEP, 1997) and approximately 91% of South Africa potentially susceptible to desertification (Hoffman and Ashwell 2001). Land degradation occurs in both communal lands (specifically in the steeply sloping environments adjacent to the escarpment in Limpopo, KwaZulu-Natal, and the Eastern Cape) and commercially-farmed lands due to complex socio-economic drivers, as well as climate change. It undermines the productive potential of land and water resources, affects human welfare, and causes extensive alien plant invasion and biodiversity loss.
Dryland Degradation in South Africa
Eighty percentage of South Africa’s land surface area is used for subsistence agriculture, but only about 11% of this is suitable for cultivation. Nearly 85% of the land cover, 10.83 million hectares (ha), is rain-fed (State of the Environment South Africa 2008). The cultivated areas cover about 12.76 million ha 82% of which roughly 10.45 million ha is permanently under cultivation.
More than 0.7 million ha of land is degraded by soil erosion and 0.19 million ha is degraded by waste rock dumps, and mining (State of the Environment South Africa 2008).
29% of the degraded area is cropland, 33% is forest and 37% is rangeland (Bai and Dent 2007).
Inter-annual rainfall variability is influenced by the El Nino-Southern Oscillation (ENSO) phenomenon (Cao and Prince 2005). The variability of rainfall reduces the land’s productivity for crops and pastures, exacerbating unsustainable land use practices, which eventually leads to the overexploitation and degradation of the land.
Increased population is another driver for land degradation in this area (Bai and Dent 2007).
Soil erosion, excessive wood harvesting and the loss of palatable pasture species contribute to land degradation (Shackleton, Shackleton, and Cousins 2001).
Overgrazing aggravates physical soil degradation in the form of crusting and soil compaction (State of the environment South Africa 2009) .
The mining and coal-burning industry practices in Gauteng and Mpumalanga results in acidification and pollution of soils (State of the environment South Africa 2009).
Deforestation for land clearing or for resource extraction also contributes to land degradation in several districts of Limpopo, KwaZulu-Natal, and in the Eastern Cape (State of the Environment South Africa 2009).
Alien plant invasion is an important contributor to vegetation degradation and loss of productivity of land. aAlien plants have invaded over 10 million ha of South Africa (see Figure 2) and make up 62% of the 319 species listed as harmful. They threaten 55% of the Red Data-listed plants in the country (State of the Environment South Africa 2009). Moreover, invasive alien species threaten biodiversity in the coastal and marine environments.
The previous apartheid regime also contributed to land degradation. During the apartheid era, 3.5 million African people were resettled in the South Africa native ‘homeland’ which is now called communal areas ( Fox and Rowntree 2001). Within these so-called communal areas, livestock numbers grew to 2–4 times the recommended stocking rates (Meadows and Hoffman 2002), causing rangeland degradation and severe soil erosion (Hoffman and Todd 2000).
Land degradation in this area impacts food and water security, economic development, and natural resources.
Land degradation results in the loss in ecosystem functioning and productivity. Net primary productivity decreased by an average of 29 kg C/ha/year over the period 1981-2003(Bai and Dent 2007).
Land degradation causes migration of rural population to the cities, resulting in overcrowding, unemployment and poorer living conditions (Eriksen and Watson 2009)
Land degradation impacts the economy as well. South Africa pays about R2 billion (US $280 Millionmillion) annually for dammaintainmaintenance and water treatment due to serious soil degradation (State of the Environment South Africa 2009).
Climatic conditions might have had a more important influence on land degradation patterns in South Africa than is currently understood (Hoffman et al. 1999).Long-term changes in rainfall patterns for South Africa have still not been conclusively demonstrated, but current climate change scenarios suggestless rain in the future, and increased variability in rainfall amounts and temperature. Hence, it is important to study the impacts of different land use practices under changing climatic circumstances.
In South Africa, people have realized the importance of environmental protection, and taken action on reducing soil and grassland degradation rates (Hoffman et al. 1999).Moreover, the increasing awareness may promote the adoption rate of conservation agriculture activities in future (State of the Environment South Africa 2009).
More research needs to be done to support government agencies in developing small scale, intensive farming practices that combine effective conservation techniques.
Cao, M., and S. D. Prince. 2005. Climate-Induced regional and interannual variations in terrestrial carbon uptake. Tellus 57: 210–217.
Clover, J. and S. Eriksen. 2009. The effects of land tenure change on sustainability: human securityand environmental change in southern African savannas. Environmental Science and Policy 12: 53-70.
Wessels K.J., Prince S.D., Malherebe J., Small J. and P.E. Frost. 2007. Can human-induced land degradation be distinguished from the effects of rainfall variability? A case study in South Africa. Journal of Arid Environments 68: 271-297. Originally published in Fox, R., and K. Rowntree. 2001. Redistribution, Restitution and Reform: Prospects for the Land in the Eastern Cape Province, South Africa. In Land Degradation, ed. Conacher, A., 167-86. Kluwer Acadamic Publishers:London.
Hoffman, M. T., and S. Todd. 2000. National review of land degradation in South Africa: the influence of biophysical and socio-economic factors. Journal of Southern African Studies 26: 743-758.
Hoffman, M.T., and A. Ashwell. 2001. Nature Divided: Land degradation in South Africa. 1-168. University of Cape Town Press, Cape Town.
Hoffman, M.T., S.W.Todd, S.D. Turner and Z Ntshona, Chapter 9: Causes of Degradation. In A National Review of Land Degradation in South Africa, ed. South African National Biodiversity Institute. http://www.sanbi.org/landdeg/(Last accessed 26 October 2009).
McCusker, B. & M. Ramudzuli. 2007. Apartheid spatial engineering and land use change in Mankweng, South Africa: 1963-2001. Geographical Journal173:56-74.
Meadows, M. E. & M. T. Hoffman. 2002. The nature, extend and causes of land degradation in South Africa: legacy of the past, lessons for the future. Area 34:428-437
Shackleton, C. M., S. E. Shackleton & B. Cousins. 2001. The role of land-based strategies in rural livelihoods: the contribution of arable production, animal husbandry and natural resource harvesting in communal areas in South Africa. Development South Africa 18(5):581-604.
State of the environment South Africa.2009.Land degradation. http://soer.deat.gov.za/themes.aspx?m=47 (Last accessed 26 October 2009)
State of the environment South Africa.2008. Land use and productivity. http://soer.deat.gov.za/themes.aspx?m=45 (Last accessed 26 October 2009)
United Nations Environment Programme, 1997. World Atlas of Desertification, 2nd Edn. ed, Middleton, N. and Thomas D.S.G. New York: Edward Arnold.