The influence of large mammalian herbivores on growth form and utilizationof mopane trees, Colophospermum mopane, in Botswana's Northern Tuli Game Reserve

Mopane veld is of great value to the general ungulate spectrum in times of drought, and it is capable of retaining its dominance in a community even i n the presence of extremely heavy browsing pressure imposed by large browsi ng mammals. Scrub mopane (hedges) has been regarded as resulting from exces sive browsing pressure by large mammals, especially elephants. Both the nut rient and chemical composition of mopane twig bark were investigated, the s easonal results being related back to the seasonal utilization of branches by large mammals. Mopane twigs were most palatable in winter. Eland feed on mopane throughout the year irrespective of palatability. Elephants were ra rely present in the scrub mopane area before the onset of spring rains, whe n the major mopane leaf flush occurs independently of rainfall. The impact of both species was not excessive and recruitment of mopane seedlings does occur. Herbivore browsing is responsible for a mopane morph which buds earl y and continues to produce accessible, nutritious leaves even when heavily browsed. Many browsing ungulates are reliant on this resource during the st ressful transition from spring to summer in south-eastern Botswana.