The assumption has long been that deforestation — easily and accurately measured from satellites — poses the greatest threat to the billions of tons of carbon stored in the biomass of the Brazilian Amazon. But forest degradation due to environmental and human disturbance is responsible for the bulk of that carbon loss, according to researchers at the University of Oklahoma. In fact, degradation — the loss of forest quality — released three times as much carbon as deforestation between 2010 and 2019, they say.
Deforestation is defined as the total removal of trees, which in the Amazon is mostly carried out to facilitate ranching or to grow crops, and historically observable from satellite. Forest degradation is a more subtle process, and in the past harder to measure and monitor, though far more widespread. Degradation is a loss in the quality and health of the forest, the result of environmental influences (such as drought, storms and intensifying heat) or human influences (such as fragmentation due to illegal logging to remove high-value trees, or from fires, which in the Brazilian Amazon are mostly set by people to make land more valuable and usable).
Although humans clear huge swathes of forest every year, this deforested area still represents only a small fraction of the Brazilian Amazon. However, human and environmental degradation can touch vast regions, leading to massive biomass loss and carbon release even in areas where trees still stand. “You might even walk
— source news.mongabay.com | Graycen Wheeler | 9 Feb 2022