Green sprouts grow from the ashes of Brazil’s refractory savannah

Aerial view of dry vegetation in the savannah known as the Cerrado in San Desiderio, western Bahia, Brazil, taken on September 26, 2023. Plants began to regrow there shortly after the recent devastating wildfires.
The massive wildfires that recently swept across Brazil have not spared its vast tropical savannahs, where green shoots are already beginning to emerge from the ashes and vast grasslands have acquired the rare gift of fire resistance. prove that you have it.
The Cerrado is the world’s most species-rich savannah, covering approximately 2 million square kilometers (770,000 square miles) in central Brazil, nearly one-fifth of the country’s total surface area.
In Brasilia National Park on the outskirts of the capital, blackened soil and charred tree trunks testify to the ferocity of the fire that razed 1,470 hectares (3,600 acres) in September.
At the time, Brazil was experiencing a record drought, with the city of Brasilia going 169 days without rain. The torch was lit during the worst wildfire season in more than a decade, which experts blame, at least in part, on climate change.
But the Cerrado, less well-known than the nearby wetlands of the Amazon and Pantanal, has a superpower. Over millions of years, they have developed some degree of resistance to flame and high temperatures.
upside down forest
“The Cerrado is an upside-down forest,” said Keiko Pellizzaro, an environmental analyst at the Chico Mendez Institute for Biodiversity Conservation, a government agency. Only a small portion of it exists.”
The Cerrado’s deep root system acts like a “pump,” drawing up groundwater “even in extreme droughts,” she said.
Meanwhile, above ground, the tree’s thick bark and fruit shells act as “insulation,” said Isabel Schmidt, a professor of ecology at the University of Brasilia.
Even when temperatures reach 800 degrees Celsius (1,470 degrees Fahrenheit), plants can survive “as if it were another hot day,” she says.
A month after the recent fires, the first rains have fallen, grass and small plants have begun to grow rapidly, and new leaves have sprouted on the charred trees of Brasilia National Park.
“Even without the rain, we would have seen some resilience,” Pelizzaro said.
“I am amazed at its ability to regenerate,” said Priscilla Elzal, a 48-year-old volunteer who took part in the Chico Mendes Research Institute’s efforts to replant native species such as donkey tail and Magonia pubescens trees in the reserve.・Rishi said. .


Brazilian professor, researcher and Cerrado restoration expert Isabel Schmidt walks through the Cerrado gardens at the Biological Institute of Brasilia on September 25, 2024.
tested to the limit
Brazilian police continue to investigate the cause of the fire that broke out in Brasilia National Park.
Most of Brazil’s wildfires are started by farmers and agribusiness workers clearing land for cattle grazing and crops.
Schmidt said the Cerrado’s vegetation has always withstood sporadic fires caused by lightning strikes during the rainy season.
But she warned that if extreme droughts become more frequent, the biome’s resilience could be tested.
“Plant and animal resistance to all types of fire has been developed over millions of years, but climate change has occurred over decades. No living organism can adapt that quickly.” she says.
The “cradle of water” is in crisis
The Cerrado is important not only for the survival of the thousands of species that call it home, but also for the water supply to much of South America.
The so-called “Cradle of Waters” is home to some of the continent’s largest rivers and aquifers.
But its role as the continent’s spring is at risk.
As the rainy season starts later each year and rainfall has decreased by an average of 8% over the past 30 years, Cerrado river flows have decreased by 15%.
Schmidt warned that if wildfires occur more frequently, “many fire-vulnerable ecosystems,” including the Cerrado, “will simply not be able to survive.”
© 2024 AFP
Source: Green sprouts spring from the ashes of Brazil’s fire-resistant savannah (November 3, 2024) from https://phys.org/news/2024-11-green-ashes-brazil-resistance-savanna.html 2024 Retrieved November 3,
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