Preliminary observations on the ability of goats to control post-burning regrowth in Acacia nigrescens/Combretum apiculatum savanna in Botswana.

Abstract

Reports the results of a browsing trial conducted to investigate the ability of goats to control post-burning woody regrowth in the eastern hardveld of Botswana. Discusses drought, stocking rate and plant tolerance in relation to management objectives; A ten hectare block which had been burned with an intense surface head fire was stocked at the rate of one goat per hectare to control the woody regrowth. After one year the block was subdivided and in one half the stocking rate increased to three goats per hectare. After two further years there was insufficient forage to sustain the high stocking rate. At this stage the bush density below two metres had been reduced by 23% and 52% in the low and high stocking rates respectively. Similarly the bush canopy below two metres had been reduced by 70% and 95%. There was greater mortality of benign browse species than of spinescent species. Adverse changes in herbaceous layer composition were recorded in the high stocking rate. Drought, stocking rate and plant tolerance to browsing are discussed in relation to management objectives.

Keywords: acacia nigrescens; botany; botswana; browsing; Bush canopies; bush canopy; bush density; combretum apiculatum; drought; Droughts; fire; forage; goats; herbaceous layer; management; mortality; Plant tolerance; Post-burning regrowth; regrowth; savanna; species composition; stocking rate; stocking rates

Journal of the Grassland Society of Southern Africa.