The Influence of Large Herbivores on Savanna Structure in Africa

Abstract

The savannas of Africa are occupied by the earth’s richest and most spectacular large mammal fauna. This fauna was even richer in the distant past and it is reasonable to expect that these large animals have long influenced the plants on which they prey and through them the form of the savannas. This long evolutionary history, the recent widespread disturbance by man and his livestock and the persistence of savannas on other continents without a similar large mammal fauna make it difficult to determine unequivocally the degree to which large wild herbivores have influenced the structure of the African savannas. There is much observational information but, apart from that on grazing systems for livestock, there is little experimentally supported evidence on the effects of large herbivores on savanna structure. The degree to which large herbivore influence is recognized rests largely on the scale and perspective with which one examines the savannas. On a continental scale large herbivore effects pale into insignificance beside that of say climate, but within a particular ecosystem the large herbivores may function as a determinant of savanna structure just as surely as fire, or frost, or man.