Changes in structure of savanna woodlands in northern Botswana following the impacts of elephants and fire

Abstract

Fluctuations in densities of woody plant species were monitored in plots within three northern Botswana woodland types subjected to elephant damage and burning. Woodlands dominated by Baikiaea plurijuga and Colophospermum mopane sustained significant changes occurring on an annual basis, whereas Acacia erioloba plots maintained a typical structure. The structure of A. erioloba woodlands appeared to be influenced by factors other than elephants and the occurrence of fire. Woodlands dominated by C. mopane plants were subjected to obtrusive elephant damage, although the densities of tall trees remained largely unchanged. The effects of fire were most prominent in B. plurijuga woodlands. Tree densities declined consistently and plants of lower height classes, such as shrubs and seedlings increased in densities in areas subjected to a high occurrence of fire.