Almost all the endangered species in the Amazon rainforest have seen their habitats negatively affected by fires over the past two decades, researchers have found.
Home to a tenth of the world’s known species and around 40 per cent of the planet’s remaining tropical forests, the Amazon ecosystem hasn’t evolved to cope with the fires that are often set within the rainforest to clear land for cattle farming.
A team led by at Florida State University says that the region appears to have entered a new phase in 2019, when Amazon fires skyrocketed following a relaxation of deforestation enforcement encouraged by Brazilian president Jair Bolsonaro. While fires in recent years have been closely studied, their impact on biodiversity has been less well-documented.
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To address the gap, Feng and colleagues combined satellite data of forest fires between 2001 and 2019 with maps of the ranges of more than 3000 species of mammals, birds, reptiles and amphibians, plus modelling to estimate the distribution of more than 11,000 plant species.
Up to 85 per cent of the region’s species that are already on the IUCN Red List of threatened species, such as the endangered white-cheeked spider monkey (Ateles marginatus), were found to have had between 5 and 15 per cent of their geographic range affected by fires, such as by a loss of habitat or fires directly killing individuals.
“Most of the species have been somehow impacted either to a small degree or a large degree,” says Feng. While most of the total 14,000-plus species only suffered a small encroachment on their ranges, the biggest impact was on endangered species and those only found in a few places, such as Remijia, a group of flowering plants.
The research also reveals how closely the impacts on biodiversity followed Brazilian government policy. The effect was greater during rampant deforestation before 2009, and disappeared almost completely between 2009 and 2018 in the face of Brazil’s anti-logging measures.
It then picked up in again in 2019 during the relaxation in enforcement under Bolsonaro, in what the team says was one of the “most extreme” years for biodiversity impacts from fires since 2009. “Policy plays a critical role in this whole process. The data shows the impact on biodiversity is very sensitive to policy,” says Feng.
The research comes with some caveats. The study doesn’t cover all the Amazon’s plants – it is missing about 14 per cent of verified species in the region – and the satellite data for the fires is likely to be an underestimate because clouds hid some blazes. “Our goal was not to get some scary number but to be conservative about what has happened,” says Feng. The true picture is likely to be worse.
Alexander Lees at Manchester Metropolitan University says: “These new estimates are still likely to be very conservative given the patchy nature of the distribution of many Amazonian species, which is not captured by existing range maps.”
Even if the amount of forest being burned stays steady in years to come, the Amazon could see worse impacts on biodiversity if fires burn the inner parts of the region because the heart of the rainforest has a greater richness of species. “In terms of the future, I’m not that optimistic. We are not allowing the forest to recover,” says Feng.
Nature
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