How the Indians terraformed America

This is quite extraordinary. It looks at an old debate - how populous were the Americas pre-1492? Almost uninhabited, or teeming with people? - and goes over the familiar ground of smallpox epidemics, etc, before starting to discuss human impact on the ecology.

Indians often worked on such a grand scale that the scope of their ambition can be hard to grasp. They created small plots, as Europeans did (about 1.5 million acres of terraces still exist in the Peruvian Andes), but they also reshaped entire landscapes to suit their purposes. A principal tool was fire...recently a growing number of researchers have come to believe that Indian societies had an enormous environmental impact on the jungle. Indeed, some anthropologists have called the Amazon forest itself a cultural artifact—that is, an artificial object...Terra preta, Woods guesses, covers at least 10 percent of Amazonia, an area the size of France. It has amazing properties, he says. Tropical rain doesn't leach nutrients from terra preta fields; instead the soil, so to speak, fights back... scientists suspect that terra preta is generated by a special suite of microorganisms that resists depletion...In a process reminiscent of dropping microorganism-rich starter into plain dough to create sourdough bread, Amazonian peoples, he believes, inoculated bad soil with a transforming bacterial charge...

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Blimey. 16th-century Amazonian Indians were bioengineering their environment.

Read the whole thing, definitely.