Alright, so before the whites showed up, there were massive civilizations living where the Amazon rainforest is today. I'm talking cities of hundreds of thousands of people numbering in the dozens. A massive population center. All those people needed food, and for the most part, they farmed. A lot of ice cream bean trees, for example. They also used controlled burning to build up soil so good we still can't replicate it perfectly today (check out terra prima). At or around the time the white devils first showed up, these population centers had already been largely abandoned due to social upheaval and/or disease. We're talking within a generation or three. By the time more white devils showed up with their book burnings and God bothering, those population centers had already become myth. Took the dumb whites another couple hundred years to figure out that the city of gold wasn't literally made of gold, but rather the massive cities surrounded by cops ready for harvest. We're juuuust now finding them using LIDAR to scan what is now rainforest floor.