generate questions: Terra preta (black earth), which is distributed over large areas in the Amazon forest, is now widely accepted as a product of indigenous soil management. The development of this fertile soil allowed agriculture and silviculture in the previously hostile environment; meaning that large portions of the Amazon rainforest are probably the result of centuries of human management, rather than naturally occurring as has previously been supposed. In the region of the Xingu tribe, remains of some of these large settlements in the middle of the Amazon forest were found in 2003 by Michael Heckenberger and colleagues of the University of Florida. Among those were evidence of roads, bridges and large plazas.
What is terra preta called? {sep_token} How much is terra preta distributed over the Amazon forest? {sep_token} What did the development of this fertile soil provide in hostile environment? {sep_token} In which region tribe were large settlements discovered? {sep_token} Who discovered this and where did they come from? {sep_token} What type of soil is considered a product of soil management by indigenous peoples in the Amazon Forest? {sep_token} The development of Terra Preta allowed for what to happen in the Amazon Forest? {sep_token} In lands attributed to what tribe are found remains of large settlements? {sep_token} Who is credited with finding evidence of large settlements in the Amazon forest? {sep_token} Evidence for what types of structures were found in 2003? {sep_token}