In the days when public values were Boer farming values, desertification was seen as a threat to rural livelihoods and a cause for concern. Government spent large sums of money subsidising farming systems that arguably, as in other parts of the world, were unsustainable. Sheep prices were high, and grants were available for fencing, water conservation and anti-erosion measures such as dams. These subsidies and measures further enabled farmers to overstock with sheep. Nowadays, there is an additional cause for concern.
Desertification implies soil erosion.
Soils are washed into streams and eventually silt-up reservoirs. The concept of desertification has been the subject of fierce debate. The vegetation of the Karoo has changed from a mix of livestock-edible grasses and shrubs, to undesirable shrubs which are less palatable to sheep. One of the problems with the loss of grasses is that a patchy shrub-dominated landscape has much bare ground, causing increased potential for rainfall runoff and soil erosion. Controversy rages around why these changes have occurred.