The Great Plains, and the savannas in Africa, Australia, and other places around the World were created by archaic man. Humans of any age have manipulated the land to suit their needs, and desires. There is nothing more delicious than a big roasted hunk of a big prarie dwelling mammal like an antalope, bison, or gazelle. Even writing about this is making me think of pan fried rib-eye! The bigger the grasslands, the bigger the herds, the bigger the steaks. These people were just as intelligent as we are, they had fire, and they had thousands of years to burn down forests to get the most wonderful thing a person could have at the time, and that was a big hunk of meat.

Native Americans ate all of the cute little horses that were in America way before Columbus arrived. A few domesticated horses escaped from the conquistador da Vaca, and so the Plains Indians really reaped the benefit of their ancestors in creating the praries, at least for 300 years. I bet that hunting a buffalo with a bow and arrow on the back of a running horse was one of the most exciting things a man could ever do, and with a rifle? Oh shit. But of course the white man turned the prarie into crops or grazing land for livestock. Returning prarie or savanna to woodlands would be undoing centruies and centuries of human interference, and return the land to it's original state.