The savanna ecology of Kidepo Valley National Park: The effects of burning and browsing on the vegetation

Summary Between 1947 and 1967 tree frequency was reduced by 30% in the Narus valley, Kidepo Valley National Park. Between 1967 and 1972 a further 50% reduction took place on experimental plots. Elephants were largely responsible. Despite a regeneration potential of c. 200 young trees per ha, very little tree regeneration was observed. Experimental fire treatments and animal–free exclosures revealed that annual burning and the current browsing pressure were independently capable of preventing tree regeneration. Fire effects were significant in the herb composition of the animal exclosures but less so on the grazed areas. This was attributed to trampling of litter on the grazed areas, which assisted termites in litter removal. Untrampled litter accumulation suppressed Themeda triandra to the benefit of Panicum maximum. Fire effects on the soil were small and impermanent.