What are the Causes of Forest Ground Fires within the Amazon?
Both logging and drought are increasing the flammability of Amazonian forests. Each year, an area of Amazonian forest is logged that is similar in size to the area that is deforested (Source: IMAZON). Logging increases the flammability of these forests by opening up the leaf canopy, allowing sunlight to penetrate to the fuel layer on the ground, and by increasing the fuel load through the production of woody debris. Even virgin forests become flammable when drought is severe. Most forests in eastern and southern Amazonia (half of the 2 million square miles of closed canopy forest in Brazilian Amazonia) are subject to severe dry seasons each year, but grow on deep clay soils that store water which trees can tap during dry seasons to avoid drought-induced leaf shedding. These forests are at the “edge” of the rainfall regime that is necessary for them to be forests, and to resist fire, and are very sensitive to slight reductions in rainfall. Droughts in Amazonia are most severe during El
