According to a Brazilian study, active fire occurrences between 2003 and 2020 in the entire Amazon region were associated more with agricultural burning and deforestation rather than extreme scarcity of water.
A new study has revealed that most of the burning of vegetation in the Amazon rainforest is to make room for pasture lands and other uses rather than because of drought.
The Amazon is home to the world/’s largest rainforest and river system, and the most biologically diverse place on Earth.
It encompasses a vast microbiome that spans eight developing nations — Brazil, Bolivia, Peru, Ecuador, Columbia, Venezuela, Guyana, and Suriname — and French Guiana, a territory of France.
Of these countries, Brazil and Bolivia accounted together for most of the fires detected in the region on the annual basis. Brazil holds 63% of the Amazon rainforest but the lowland tropical rainforest biome also extends into Bolivia, Colombia, Ecuador, Guyana, French Guiana, Peru, Suriname and Venezuela.
The Brazilian Amazon is experiencing an increase in fires once again. According to INPE, the number of fires discovered in the first nine months of 2022—particularly in August and September—was the greatest since 102,409 fires were detected in 2010. Deforestation in the biome has also exceeded 10,000 square kilometers per year since 2019, which is the highest amount since 2009. This trend is continuing according to figures provided by DETER, INPE's deforestation alert program.
“The scientific literature on fire in the Amazon has tended to focus on the Brazilian portion of the biome,” the authors wrote about their research. “We extended the scope to the other countries in order to find out where fire is most critical and merits attention, particularly in light of the different land uses and types of plant cover.
“We concluded that fire is used in agriculture to renew the vegetation, mainly in pasturelands and especially in Brazil, but without proper fire management, heightening the risk of fire escaping into adjacent forest and causing wildfires,” said Marcus Vinicius de Freitas Silveira, a PhD candidate in INPE’s Earth Observation and Geoinformatics Division (DIOTG) and first author of the article.
“By analyzing this long period, we were able to identify anomalies in the time series, such as 2020. The results show dissemination of the use of fire throughout the Amazon, both in clearing and burning the forest and for continuing management of pasturelands,” said Luiz Eduardo Oliveira e Cruz de Aragão, head of DIOTG-INPE and last author of the article and the leader of the Tropical Ecosystems and Environmental Sciences (TREES) Laboratory. He is also a participant in the FAPESP Research Program on Global Climate Change (RPGCC), which sponsored the study.
The Pantanal, the largest wetlands in the world and part and which is located in Argentina and Paraguay, is another significant Brazilian ecosystem that was also severely damaged by extraordinary burning in 2020. In 2020, the water surface area decreased 34% more than it did on a yearly average, according to a report published in July 2022.
According to the study, which was also supported by FAPESP, fire-related human activities are responsible for fires in the Pantanal, with 70% occurring on rural properties, 5% on Indigenous reserves and 10% in protected areas.
In Maranhão, a state in northeastern Brazil, fires increased by 18% between January and September compared with the first nine months of 2021.
“As noted in our article, recent fire activity in the region is closely linked to deforestation, which has increased because of the weakening of both federal and state environmental controls,” said Celso Silva-Junior, affiliated with the State University of Maranhão (UEMA) and second author of the article.
The study revealed that Brazil and Bolivia have contributed on average, 73% and 14.5%, respectively, of annual active fire detections in the Amazon between 2003 and 2020.