This year, the Pantanal biome is going through an unprecedented crisis. The biome, known for its areas that remain flooded for up to six months, is facing a historic drought that is boosting wildfires.
In the first half of this year alone, 468,000 hectares of vegetation burned in the Pantanal - the largest area ever recorded by satellite monitoring carried out by the Brazilian organization MapBiomas since 1985. The area consumed by fire was 529% larger than the 40-year average.
During this period, the flooded area also decreased by around 60% compared to the average. Of all the biomes in Brazil, the Pantanal is the most affected by drought.
According to experts interviewed by Brasil de Fato, all of this has to do with human activity inside and outside the region.
Global warming
Climate change, which has intensified due to greenhouse gas emissions, has changed rainfall frequency. According to agronomist Eduardo Rosa, from MapBiomas, it no longer rains like it used to in the Upper Paraguay river basin, in the Brazilian states of Mato Grosso and Mato Grosso do Sul. This plateau area is crucial for the Pantanal because the rivers that cross the plains are born there.
With less rainfall, however, these rivers no longer overflow. Therefore, they don't flood the Pantanal areas as seen every year.
“Episodic droughts often have consequences twice harder as a result of global warming,” added Carlos Bocuhy, president of the Brazilian Environmental Protection Institute (Proam, in Portuguese). “The flying rivers of the Amazon were diverted from the Mid-West region by the heat dome of the drought. They ended up hitting the state of Rio Grande do Sul hard.”
Land use
Bocuhy also said that even when it rains, the water doesn't reach the Pantanal like it used to. According to him, this is related to changes in the way the region has been occupied in recent decades. “Deforestation, the removal of forests and the use of land for agribusiness and livestock farming: it all contributes to weakening ecosystems,” he said.
Without native vegetation, rainwater penetrates less into the soil. It evaporates more quickly or flows directly into rivers, bringing with it more sediment, which adds to damaging of watercourses.
With less water underground, springs become less abundant. In periods of drought, they are no longer able to maintain water levels at their historical average.
Eduardo Rosa, from MapBiomas, confirms the problem. He explains that the plateau that supplies the Pantanal had 23% of its territory used for agriculture and livestock farming in 1985. Today, it is 42%. The occupation of the territory by crops and cattle removed 2.1 million hectares of forest and 2.7 million hectares of savannah, which are now needed for balancing the flood regime in Brazilian wetlands.
“There is a climate problem, but there is also the issue of soil protection and destruction of native vegetation,” he said.
Dams
Another problem is that several dams have been built on rivers that supply the Pantanal, constructions made mainly for power generation. A 2022 study warned about the cumulative effect of these structures on the biome, compromising flood regimes.
A publication by the Brazilian organization Ecoa (Ecology and Action) listed 50 dams on the Pantanal rivers, seven of them large ones. The organization also pointed out that another 13 were under construction and 125 were planned for the region.
Fires
Rosa added that the lack of water has changed wildfire dynamics in the Pantanal. He explained that fires have always been used for land management in the region. Today, however, what used to be a tool has much greater destructive potential, as wildfires advance over a drier environment.
“In the past, fires were more related to grassland vegetation in the area surrounding the biome. Now, we see it around the Paraguay River, an area that used to be permanently flooded,” he said. “Before, fire didn’t reach these areas, but now it happens and affects wild animals more.”
Data from the Mato Grosso do Sul Department of the Environment shows that 90% of fires in the Pantanal biome are caused by human action. Rosa said that, with the changes in the biome, wildfires tend to become increasingly uncontrollable. The use of fire as a tool was banned in the region in May to curb its spreading.
According to Brazil’s Ministry of the Environment, around 96% of the wildfires recorded in the Pantanal had been put out or controlled by last week. Of the 55 fires identified in the biome as of July 14, 31 have been extinguished. Of the 24 fires that were still active, 22 were controlled.
More than 830 federal government professionals worked to put out fires in the region, supported by 27 boats and 14 aeroplanes.
Edited by: Martina Medina
