After all those surveys of the western Amazon basin and the subsequent stories of lots of settlements with plazas and temples and so on we come head to face with the counter attack – it doesn't suit the Greens that people might get the idea the Amazon jungle has been cut down once before, not so long ago, so what is wrong with logging it in the 21st century – go to http://popular-archaeology.com/issue/fall-2015/article/pre-contact-amazo… … where the main thrust of the argument is that the settlements and farming activity was restricted to the river banks of the Amazon and its tributaries whilst the interior, which is vast, was little affected. I think that is basically what archaeologists were saying at the time – but the effect of the new article is to undermine the discoveries (or that is the hope). The study is in the Journal of Biogeography (October 28th 2015).
However, there is an article in New Scientist of the same week which may go some way to answer some of the questions. It concerns the discovery that hunter gatherer tribes people in various parts of the world, such as Borneo, were managing the rainforest long before the modern period and the introduction of farming. They favoured certain plants and trees, and provided light and room for them to grow and of course took cuttings etc to propagate them. The Maya are known to have practised a similar kind of exploitation of tropical forest, particularly in the cultivation of vanilla pods (from a species of orchid) and therefore there is no reason why the Amazon rain forest was any different, and by the process of development, and outside introduction (trade and discourse) the idea of cities in the jungle came into being. If it had not been for the 14th century downturn it may have led to a massive disruption of Amazonia (as far as the forest is concerned) so saying their footprint was slight is just a fortunate accident of fate as it could easily have been a severely reduced jungle-scape that the Spaniards found when they entered the region in the following centuries.