Grasslands and Thickets: Bush Encroachment and Herding in the Kalahari Thornveld

Abstract

This paper addresses bush encroachment around Kuruman, South Africa. The 'received wisdom' is that bushes result from overgrazing, displace the climax community, and lower carrying capacity. In contrast, this paper is informed by non-equilibrium ecological and range management science, as well as recent challenges to degradationist interpretations about environmental change in Africa. To what extent has bush encroachment occurred? Has a consequent drop in sustainability contributed to dependence upon wage labour among black households? Using documentary evidence, the paper establishes a broad chronology for change. It asserts that because of non-human and human factors black herders live in a bushier environment than they did when the first travellers arrived around 1800. It concludes with oral evidence to consider the effects of the change. Interviews show that people do not consider bush encroachment to be an environmental problem. They are too poor to keep many grazing cattle, and the browsing small stock and donkeys they can afford are well suited to bushes. Also, because bushes survive drought better than grass, they are valued fodder for all animals. Dependence upon wage labour results from wider social factors and this environmental change has not degraded livelihoods.

Effects of Sicklebush (Dichrostachys cinerea (l.) wight and arn.shrub) Encroachment on Floristic and Vegetation Structure in Semi-arid Savannah of Southern Ethiopia

“…The low aboveground plant biomass in sicklebush encroached site is also complemented by various studies (e.g. Dean and Macdonald, 1994;Jacobs, 2000;Smit, 2004).…”

“…insculpta, C. plumulosus, T. flavescens, Indigofera sp., Otostegia sp., D. radicans, and R. minima showed significance difference whereas the rest did not. Bush encroachment, since it lowers grazing capacity, affects plant height and, this reduces wildlife abundance (Dean and Macdonald, 1994;Jacobs, 2000;Smit, 2004), is a global concern. One indicator for savannah degradation is a decrease in vegetation height (Tobler et al, 2003) although the height of the vegetation was comparable except for individual species as pointed earlier.…”

“…These species also tend to have very high levels of phenolic compounds in their leaves, which reduce their digestibility to livestock and wildlife. The combination of thorniness and low digestibility of Acacia trees and other Fabaceae species reduce their accessibility and natural value to consumers (Jacobs, 2000).…”

Impact of land use and land cover change on land degradation in rural semi-arid South Africa: case of the Greater Sekhukhune District Municipality

“…Since the area is within the savanna biome, it has a high tendency of crusting that facilitates high runoff and erosion that depletes topsoil organic matter (Mills & Fey, 2004 ). The poor soils induce the generation of hardy shrubs that can survive on lower quality soils (Jacobs, 2000 ). Another reason for the significant decline of thicket/dense bush and other classes such as subsistence and commercial cultivation is that the vegetation and soil productivity is often unable to recover after dry seasons due to prolonged drought and/or anthropogenic activities.…”

Silences of Grass: Retrieving the Role of Pasture Plants in the Development of New Zealand and the British Empire

“…33 Environment and History, which has been running for a decade, has plenty on forests and deforestation, conservation, ecology and water but only one article on grasslands, in the Kalihari desert. 34 It is the same in the pages of the American periodical Environmental History. It has published articles on the life of conservationists, on constructions of nature and of wilderness, on forestry, water, rivers and regions, but only one on grass.…”