The following remarks are based on Trollope and Trollope (1999), de Ronde et al. (1990), de Ronde (1999, 2000) and van Wilgen et al. (1990).
Forestry
In Namibia specific guidelines have been formulated for the management of forested areas where fire occurs as a natural factor of the environment. The primary reason for prescribed burning in these areas is to reduce fuel loads in order to reduce fire intensity, thereby reducing the negative effect of fires on the recruitment and development of valuable timber species like Baikiaea plurijuga (teak) and Pterocarpus angolensis (kiaat).
The use of prescribed fire for fuel reduction in forest plantations has been promoted in Africa for many years. The main candidates for prescribed burning are pine (Pinus spp.) plantations.
Nature Conservation
Prescribed fire is commonly used in South Africa to maintain biodiversity in sclerophyllous shrubland (fynbos) ecosystems, including the prevention of tree invasion.
The usual reasons for burning rangeland in nature conservation areas are:
• to remove moribund and/or unacceptable grass material;
• to control and/or prevent the encroachment of undesirable plants; and
• to encourage wildlife to move to less preferred areas in order to minimise the overgrazing of preferred areas. Such burns are normally coordinated with the two preceding reasons if possible
Livestock farming
The reasons for burning rangeland for livestock farming are:
• to remove moribund and/or unacceptable grass material; and
• to control and/or prevent the encroachment of undesirable plants.
An often-quoted reason for burning rangeland is to stimulate out-of-season green growth. This is often done during the late growing season or late dry season to provide grazing for livestock. This practice is completely unacceptable because:
• it reduces the vigour of the grass sward;
• it reduces the canopy and basal cover of the grass sward;
• it increases the runoff of rain water; and
• it can result in increased soil erosion.
Production of grass thatching material
Prescribed burning for the production of grass thatching material is apparently unique to Namibia where it is widely practised in the northeastern regions in areas receiving higher rainfall (700 mm per annum) or that are subject to annual flooding. The primary reason for controlled burning is to remove old dead thatching material that has accumulated after harvesting so as to ensure the production of new, high quality material.
