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 has declined significantly in the Brazilian Amazon between 2004 and 2014, there has been an increase to the present day. Environmentalists are concerned about loss of biodiversity that will result from destruction of the forest, and also about the release of the carbon contained within the vegetation, which could accelerate global warming. Amazonian evergreen forests account for about 10% of the world's terrestrial primary productivity and 10% of the carbon stores in ecosystems – of the order of 1.1 × 10 metric tonnes of carbon. Amazonian forests are estimated to have accumulated 0.62 ± 0.37 tons of carbon per hectare