Deforestation of the Amazon rainforest The completion of the roads was followed by a wave of resettlement; these settlers had a significant effect on the forest as well. Research conducted by Leydimere Oliveira et al. has shown that the more rainforest is logged in the Amazon, the less precipitation reaches the area and so the lower the yield per hectare becomes. Thus for Brazil as a whole, there is no economic gain to be made by logging and selling trees and using the logged land for pastoral purposes. A September 2016 Amazon Watch report concludes that imports of crude oil by the US are driving
Amazon rainforest on the eastern side flowed toward the Atlantic, while to the west water flowed toward the Pacific across the Amazonas Basin. As the Andes Mountains rose, however, a large basin was created that enclosed a lake; now known as the Solimões Basin. Within the last 5–10 million years, this accumulating water broke through the Purus Arch, joining the easterly flow toward the Atlantic. There is evidence that there have been significant changes in Amazon rainforest vegetation over the last 21,000 years through the Last Glacial Maximum (LGM) and subsequent deglaciation. Analyses of sediment deposits from Amazon basin paleolakes and from