Environmental Problems, Their Causes, and Sustainability 1

Beisa oryxCape buffaloWildebeestTopiWarthogDry GrasslandThompson'sgazelleWaterbuckMoist GrasslandGrant's zebraGiraffeAfrican elephantGerenukBlack rhinoDik-dikDry Thorn ScrubEast AfricanelandBlue duiker Greater kudu BushbuckRiverine ForestFigure 6-23 Natural capital: some of the grazing animals found in different parts of the African savanna.These species share vegetation resources by occupying different feeding niches.Many large savanna animal species are killed fortheir economically valuable coats and parts (tigers),tusks (rhinoceroses), and ivory tusks (elephants).Humans have attempted to raise cattle in somesavanna areas. Often these herds have helped convertsavannas to deserts. One reason is that cattle require alot more water than native herbivores (Figure 6-23)that are better adapted to the savanna climate. To getenough water the cattle must move back and forth betweenwater holes. This frequent movement reduces116 CHAPTER 6 Climate and Terrestrial Biodiversity