Ecosystem management of veld in Kudumane and Ganyesa, South Africa

The savanna biome is the largest biome in South Africa. It is characterised by a grassy ground layer and a distinct upper layer of woody plants. Livestock farming is a major factor to impact the structure and function of savanna. The Ganyesa and Kudumane districts of South Africa are characterised by dry climate and Kalahari thornveld and bushveld (one kind of savanna). Based on investigation, typical permanent plots of bare soil, ungrazed veld, moderately grazed veld, and heavily grazed veld are established to study the structure, function and management of veld ecosystem. The results show that the number of species and individual decrease under grazing condition, highly desirable grass species mainly appear in ungrazed veld while less desirable and undesirable grass species mainly grow in moderately grazed and heavily grazed veld. Shrub--Acacia mellifera tends to be predominant under grazing disturbance. The surface runoff and sediment loss increase while soil organic C, and soil total N decrease under grazing condition. During the natural succession of veld, there is a delicate balance between the tree and grass components of the savanna vegetation. It is clear that the main cause of veld degradation is overgrazing. We developed the new state and transition model to show the process of veld degradation and veld restoration. With the objectives of attaining sustainable communal land use and improved livestock production to improve people's livelihoods in the research area, some development options are identified.