In african savannas elephants are a keystone species. elephants eat small trees, such as acacia, that grow on the savanna. even if an acacia tree grows to a height of several feet, elephants are able to knock over the tree and uproot it. imagine a drastic decline the elephant population that live within the african savannas. what would be the inevitable result? a) the savanna would decline and evolve into a desert ecosystem. b) predators would replace the elephants as the keystone species. c) another large herbivore would immigrate and replace the elephant. d) the savanna would succumb to succession and evolve into a woodland.