Amazonia: 85% of threatened species affected by forest fires

Between 2001 and 2020, between 103,000 and 190,000 square kilometers of the Amazon rainforest were affected by forest fires, affecting thousands ofcash animals and plants, reveals a new study published in Nature. An area equivalent to 2.5 times the Occitanie region. Researchers examined the impact of these forest fires on more than 11,000 plant species and 3,000 species of vertebrates present in the Amazon rainforest. They calculated that 64% of them were weakened by these fires, sometimes significantly. ” There are 263 to 700 species for which more than 10% of their range has disappeared “, Say the researchers. For every 10,000 km² of forest that suffers a fire, 27 to 37 additional plant species and 2 to 3 vertebrate species are impacted.

Endangered species with a smaller habitat

The figure is even more impressive for species classified as threatened : between 77 and 85% were affected by fires. This is due to the fact that this category of species often occupies a restricted area of ​​distribution: the destruction of habitats can then directly lead them to disappearance or to further reduce the size of their territory. In addition, as fires penetrate deeper into the forest, the number of species first encountering forest fires increases. Gold, ” as Amazonian species have largely evolved in the absence of fire, they generally lack adaptation to fire damage », Warns Xiao Feng, biogeographer at the University of Florida and main author of the study.

Intentional fires on the rise since Jair Bolsonaro came to power

The forest fires are not all of natural origin. Many fires are thus deliberately lit by farmers in order to clear space to allow the cultivation of Soy or exploit pastures for cattle. This policy, which had been limited by a series of laws in 2009, resumed with a vengeance from 2019 with the coming to power of Jair Bolsonaro, a president who is not particularly concerned about environmental issues. Thus, between January and August 2019, 73,000 fires were recorded in Brazil, half of which in the Amazon rainforest, an increase of 60% compared to the previous three years. And things did not get better in 2020, with more than 100,000 fires detected in the Amazon during the year according to the National Institute for Space Research (INPE).

These arson attacks have catastrophic consequences on the biodiversity. « The fires associated with deforestation usually result in complete loss of forest habitat, and burning of vegetation interferes with regeneration and facilitates invasion of exotic grasses, explique Xiao Feng. Deforestation [par brûlage, ndlr] increases the flammability of the remaining forests by increasing the density of edges, local temperatures and reducing precipitation. The continued loss of forest cover and biodiversity could ruin the resilience from ecosystems and accelerate an irreversible tipping point. A 20-25% loss of Amazonian forests could precipitate a rapid transition to savannah-like vegetation », Concludes the researcher.

In response to this disaster, the Brazilian government proposed last February to outsource the protection of the Amazon rainforest to private companies. The French group Carrefour thus joined the program by committing to pay 600,000 euros per year to finance the protection of 75,000 hectares in the state of Rondônia. Will this policy be effective? Nothing is less sure.