Amazon Rainforest Threatened by Devastating Human Impacts: Fires and Logging

We all know that the Amazon rainforest is suffering from human impacts. But how much are we really affecting this biodiversity hotspot? Scientists have discovered that the human impact on this rainforest has been grossly underestimated, and that the ecosystem may be in some serious danger.

In this case, the researchers wanted to examine how logging, intentionally-lit fires and other human impacts. The scientists estimated above and below-ground carbon loss from selective logging and ground level forest fires in the tropics, based on data from 70,000 sampled trees and thousands of soil, litter and dead wood samples from 225 sites in the eastern Brazilian Amazon.

So what did they find? It turns out that selective logging and surface wildfires can result in an annual loss of 54 billion tons of carbon from the Brazilian Amazon. This is equivalent to about 40 percent of the yearly carbon loss from deforestation, which is when entire forests are chopped down.

"The impacts of fire and logging in tropical forests have always been largely overlooked by both the scientific community and policy makers who are primarily concerned with deforestation," said Erika Berenguer, one of the researchers, in a news release. "Yet our results show how these disturbances can severely degrade the forest, with huge amounts of carbon being transferred from plant matter straight into the atmosphere."

Once a forest has been logged, many gaps in the canopy mean that the forest becomes much drier due to sun and wind exposure. This increases the risk of wildfires spreading inside the forest. In addition, the changes can turn primary forests into a thick scrub full of smaller trees and vines, which store far less carbon than undisturbed forests.

"Our findings also draw attention to the necessity for Brazil to implement more effective policies for reducing the use of fire in agriculture, as fires can both devastate private property, and escape into surrounding forests causing widespread degradation," said Joice Ferreira, one of the researchers, in a news release. "Bringing fire and illegal logging under control is key to reaching our national commitment to reducing carbon emissions."

The findings are published in the journal Global Change Biology.