More than two thirds of the area burned was native vegetation
Between 1985 and 2023, 199.1 million hectares were burned at least once in Brazil, according to data from the most recent MapBiomas Fire Collection on the extent of burned areas in the country, representing almost a quarter (23%) of the national territory. More than two thirds of the area affected by fire (68.4%) was native vegetation; approximately one third (31.6%) in anthropized areas, such as pasture and agriculture. Almost half (46%) of the burned area is concentrated in three states: Mato Grosso, Pará and Maranhão, and 60% of all burned area was on private property. Translated with DeepL.com (free version)
Each year, an average of 18.3 million hectares, or 2.2% of the country, are affected by fire. The dry season, between July and October, accounts for 79% of the area burned in Brazil, with September accounting for a third of the total (33%). The MapBiomas Fogo data also shows that around 65% of the area affected by fire in the country has been burned more than once in 39 years, with the Cerrado being the biome with the largest amount of recurrent burned area.
The data shows clear historical patterns about what, when and how much burns in Brazil every year, which allows public authorities to understand trends, identify the areas most at risk and establish coordinated and more efficient actions to combat fires. In this sense, the Cerrado and the Amazon, which together account for most of the burned area in the country, present unique characteristics and challenges that demand specific approaches.
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Together, the Cerrado and the Amazon have concentrated around 86% of the area burned at least once in Brazil in 39 years. In the Cerrado, there were 88.5 million hectares, or 44% of the national total. In the Amazon, 82.7 million hectares (42%) were burned. Although the Cerrado and the Amazon have similar absolute numbers of burned areas, these biomes are different in size. Therefore, in the case of the Cerrado, the area burned is equivalent to 44% of its territory; in the Amazon, this percentage was 19.6%, or one fifth of the biome's extension.
"The Amazon faces a high risk of fires due to its vegetation not being adapted to fire, aggravating the level of environmental degradation and threatening local biodiversity, while the historic drought and insufficient rainfall to replenish the water table intensify the region's vulnerability," explains Ane Alencar, coordinator of MapBiomas Fogo and director of Sciences at IPAM. "The Cerrado has suffered from high rates of deforestation, resulting in an increase in fires and the risk of them becoming uncontrolled, altering the natural fire regime. These changes have a negative impact on the ecological balance, because fire, although a natural component of the Cerrado, is occurring with a frequency and intensity that the vegetation cannot withstand," explains Vera Arruda, technical coordinator of MapBiomas Fogo and a researcher at IPAM.
The difference between the biomes is not just the numbers, but also the characteristics of fire. In the Amazon, fire is mainly caused by deforestation and agricultural practices. As this biome is extremely sensitive to fire, the result is a huge loss of biodiversity. In the case of the Cerrado, the biome is adapted to fire, since evolutionarily it depends on natural and controlled burning to maintain its ecosystem. However, the figures show that it is currently facing changes in its natural fire regime related to agricultural expansion and improper use of fire.
The biome that burned the most in proportion to its area in the 39 years evaluated was the Pantanal, with 9 million hectares. Although this is only 4.5% of the national total, it is 59.2% of the biome. In 2023, more than 600,000 hectares were burned in the Pantanal, 97% of which occurred between September and December. The month of November accounted for 60% of the total area burned. The Pantanal, which is also adapted to fire, faces intense fires mainly due to prolonged droughts. Because of the difficulties in containing fires, any outbreak can have a significant impact on the local fauna and flora.
The area burned in the Caatinga between 1985 and 2023 was almost 11 million hectares. This is equivalent to 6% of the national total and 12.7% of the biome. In this biome, fires are often used for agricultural management and exacerbated by prolonged droughts, with many plant species showing adaptations to fire.
In the Atlantic Forest, there were around 7.5 million hectares (4% of the national total and 6.8% in relation to the size of the biome). The Atlantic Forest is highly sensitive to fire in the remaining natural areas. Forest fragmentation and urbanization have increased its vulnerability to fires, which threaten its biodiversity.
In the Pampa, there were 518,000 hectares, or 2.7% of its territory. In this biome, where grassland vegetation predominates, fires are small and infrequent, since their use for grazing cattle results in a low accumulation of flammable biomass. The biggest fires usually occur in the years of the La Niña climate phenomenon.
In addition to the addition of the area burned in 2023, a new data point in Collection 3 is the size of the scars, which counts the area affected by a single fire event. Burned areas between 10,000 and 50,000 hectares are predominant in the Pantanal, with around 25% of the affected areas. In the case of the Cerrado, burn-offs in areas between 1,000 and 5,000 hectares predominate, accounting for 20% of the total. In the Amazon, areas between 100 and 500 hectares predominate, accounting for around 20% of the total affected by fire in this biome. Areas of less than 10 hectares or between 10 and 50 hectares are predominant in the Caatinga and Atlantic Forest. In the case of the Pampa, more than 54% of burned areas are smaller than 10 hectares.
The three municipalities that burned the most between 1985 and 2023 were Corumbá (MS), in the Pantanal, followed by São Felix do Xingú (PA), in the Amazon, and Formosa do Rio Preto (BA), in the Cerrado.