Amazon: How long does it take to regenerate the forest consumed by fires

However, many animals and plants are threatened by fires ravaging the region a few weeks ago. The llamas are not limited to the Brazilian Amazon, they also affect the forests of Bolivia and Paraguay.

The images are dark: smoke and flames have covered hundreds of thousands of acres of jungle.

Satellite data from the National Institute of Space Research of Brazil (INPE, in Portuguese) indicate that, since the beginning of the year, fires have increased by more than 80% in Brazil compared to the same months from the previous year. 2018.

But how long does it take to regenerate the Amazon rainforest?

Professor of Ecosystems Science at Oxford University (England), Yadvinder Malhi, said that "the forest takes between 20 and 40 years, if allowed to regenerate".

However, in a conversation with BBC Mundo, the academic points out that there are several aspects that can affect this recovery.

One of them is how much scorched earth is damaged. If he has suffered several fires, he says, he is more likely to have irreversible damage and his recovery will be much slower.

Another factor is related to the proximity of the land burned in a forest without damage.

"If it's next to an intact forest, birds and animals will naturally go into the damaged area and help with regeneration." Otherwise, says Malhi, "it will be much more difficult because seeds and species will have to be introduced".

Climate change and deforestation

Climate change is another factor that can determine the speed with which the burned hectares will regenerate.

Claire Wordley, a researcher in the Department of Zoology at the University of Cambridge, England, explains that this factor is extremely difficult to predict and control.

"It has already been predicted that if the temperature gets very high, the Amazon will not be able to produce enough rain to maintain its rainforest.So then, it's too hot, it can become a savannah, "he told BBC Mundo.

According to the academic, although it is difficult to estimate how long it will take for the damaged forest to recover, it is clear that it will not take ten years. "It can be hundreds," he says.

On the other hand, land use for agriculture and deforestation can also be a hindrance to prevent land reclamation.

For the researcher in ecology Phil Martin, although the recovery of plants and trees "may take between 150 and 200 years", it would be "in perfect condition".

"The problem today is that farmers and livestock are affecting multiple areas, climate change can also have an impact, we now find that fires are much more frequent and destructive." than before, "he said.

Structure changes

Fires significantly alter the vegetation structure of a particular place. And this, in turn, affects the species that live in the area.

That's what José María Cardoso da Silva, professor in the Department of Geography and Regional Studies at the University of Miami (USA) said. For the scientist, the recovery of the species can take several decades, even centuries, or even more difficult if the fires follow one another.

"If fires become the norm in the landscape, forests will never regenerate in their natural state and we will see a new type of impoverished vegetation dominated by a few common tree species that can survive in the new rainy season. fires, "he said. to the BBC Mundo.

Da Silva adds that "fires can also facilitate the spread of invasive species that, over time, can limit the regeneration of natural ecosystems".

Are fires part of the Amazonian ecosystem?

Another fact to consider in understanding how difficult it will be to recover the affected areas is that fires in the Amazon rainforest do not occur naturally.

"In many parts of the world, fire is part of the ecosystem, but in the rainforest, the trees are unprepared, they have never experienced a fire," says Malhi.

"Even small fires can kill a lot of trees, which can be very harmful," he says.

Researcher Claire Wordley shares this view.

"Some regions, such as Australia or parts of the United States, are ready to face fires, but the Amazon region does not have the same capacity." South America is the most One of the regions that recovers more slowly after a fire, "he said.

According to studies, even three decades after being affected by a fire, burned forests contain 25% less carbon than those not targeted by flames. And it is that the Amazon does not have a mechanism of protection against the fire and that it generates a much more important mortality of the trees.

"This shows that it takes decades, if not hundreds of years, for forests to recover from a fire," Brazil's Erika Berenguer of Brazil told BBC News Brazil. University of Oxford.

"We have huge trees that are falling, they will die, then thin trees can come in. These new trees grow fast, but they have low wood density and they retain little carbon," the researcher adds.

BBC