Controlling bush encroachment with fire in the savanna areas of South Africa

Abstract

The savanna areas of South Africa can be divided into the moist and arid savanna types according to the availability of soil moisture. Bush encroachment is a serious veld management problem in all the savanna areas and veld burning is a potential eradication technique in situations with an adequate grass cover to support an intense fire. In the moist savannas fire per se can be used to control bush encroachment but in the arid savannas it has the role of maintaining trees and shrubs at an available height and in acceptable state for browsing animals. Intense head fires applied at the end of the dormant season are used for bush eradication. The frequency of burning is relatively high in the moist savannas but is very low in the arid savannas, being usually limited to years with above average rainfall when adequate grass fuel loads can be accumulated. Veld burning provides an attractive economic and energy saving technique of solving the problem of bush encroachment in the savanna areas of South Africa.

Uittreksel

Die savanna gebiede van Suid‐Afrika kan volgens die beskikbaarheid van grondvog verdeel word in die nat en droë tipes. Bos‐indringing is ‘n ernstige veldbestuursvraagstuk in al die gebiede, en veldbrand is ‘n potensiële uitroeingstegniek onder toestande met voldoende grasbedekking om ‘n in intense vuur te ondersteun. In die nat savannes kan brand sodanig gebruik word om bos‐indringing te beheer, maar in die droë savannes is die rol van brand om borne en struike op ‘n bereikbare hoogte en in ‘n aanvaarbare toestand vir struik‐vretende diere te hou. Intense voorvure, toegepas teen die einde van die russeisoen, word gebruik vir bos‐uitroeiing. Die frekwensie van brand is relatief hoog in die nat savannes, maar is baie laag in die droë tipes, en is gewoonlik beperk tot jare met ‘n bo‐gemiddelde reënval wanneer voldoende gras as brandstof kan ophoop. Veldbrand verskaf ‘n aanloklike ekonomiese en energie‐besparende tegniek vir die oplossing van die probleem van bos‐indringing in die savannes van Suid‐Afrika.