This chapter deals with topography, climate and soil as physical determinants of rangeland productivity, followed by the contribution and ecological impact of different biomes. Rangelands cover half the world’s land area, and in the arid to semi-arid environments of South Africa, they comprise even more than 75% of the agricultural land surface that can be utilized only by livestock and game farming. Physical barriers provided by the Great Escarpment and the Drakensberg mountains determine the climate and vegetation of most of the rangeland regions of South Africa. The evaluation of ecological processes on rangelands is made through the assessment and monitoring of soil and vegetation indicators, which provide information about the functional status of soil and rangelands. A rangeland management system is consequently a combination of resting- and grazing periods, in which the principles and objectives of rangeland, livestock and game management are incorporated.