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Introduction
The phenomenon of land transformation is common to all past and present human cultures and occurs in all regions of the world. Since the early habitation of the Earth, human actions have affected the soil and biotic resources as a result of basic human needs. Land transformation has accelerated and diversified with the onset of the Industrial Revolution, globalisation of the world economy, and the expansion of the human population and technological capacity. As human pressures on the Earth system accelerate, several critical global, regional and local thresholds are being exceeded, which could result in abrupt - and possibly irreversible - changes to the life-support functions of the planet. Such changes are likely to have substantial implications for human well-being (United Nations Environment Programme 2012:6).
Land transformation involves changes in land use and land cover. Land use refers to the human utilisation of land and change may involve either a shift to a different use or an intensification of an existing one. Land cover refers to the physical state of the land and embraces the quality and type of surface vegetation, water and earth materials (Turner & Meyer 1994:5). Land use and land cover influence each other. For the purpose of this study, the term ‘land categories’ has been used to encompass aspects of both land use and land cover.
A change in land use may be initiated to achieve a specific aim. However, it may result in irreversible changes to land cover, with associated negative impacts such as extensive loss of grassland. In South Africa, the Grassland Biome hosts a high diversity and endemism of plant and animal species (Egoh et al. 2011:2). The biome ranges from dry in the west to mesic in the east, with the eastern portion containing patches of forest (Mucina & Rutherford 2006:44). A disproportionate amount of the biome’s biodiversity is found within the moist eastern portion (Mucina & Rutherford 2006:362-363). Agriculturally, this biome is South Africa’s most productive (Neke & Du Plessis 2004:468). Given that the moist portion of the biome receives more rainfall than other portions, considerable pressure from agricultural development, with consequent biodiversity loss, can be expected.
Irreversible changes in land cover have resulted in a reduction of both the quantity and the quality...