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 Eocene era. It appeared following a global reduction of tropical temperatures when the Atlantic Ocean had widened sufficiently to provide a warm, moist climate to the Amazon basin. The rainforest has been in existence for at least 55 million years, and most of the region remained free of savanna-type biomes at least until the current ice age, when the climate was drier and savanna more widespread. Following the Cretaceous–Paleogene extinction event, the extinction of the dinosaurs and the wetter climate may have allowed the tropical rainforest to spread out across the continent. From 66–34 Mya, the rainforest extended as far