The people who lived in the Amazon regions back before any Europeans showed up on the scene had an ingenious way to survive there. By creating mounds of biochar, the pre-Columbian peoples made beds for their crops that drained far better than the native soil, which is nutrient-poor and prone to flooding. And, it seems, they unintentionally contributed to the biodiversity of the region. In a study in the Proceedings of the National Academy of Sciences, scientists led by Doyle McKey of France investigated the savannas of French Guiana, in the far northern part of South America.