Cerrado: judicious use of fire helps prevent wildfires – 09/10/2023 – Environment

With a lighter and a gallon of fuel, brigadista Rogério Borges sets fire to a section of the Serra do Tombador Natural Reserve, in the northwest of Goiás. In a straight line, he walks making a line with the so-called pinga-fogo, a type of “watering can” that has a twisted spout, made especially for this task.

“This ‘knot’ is what prevents the fire from rising into the fire trap”, he explains, dressed from head to toe in protective equipment.

Most flames are small, but some reach the height of an adult. They lick the undergrowth in the heart of the cerrado and move quickly over the grass yellowed by months of drought.

Attentive to the advance of the fire, Borges watches as the heat that rises from the ground increases and multiplies that which is in the air even in the late afternoon. Afterwards, he lights another trail, on the opposite side to the first. The stretch of vegetation is surrounded by two dirt roads and the flames do not cross this boundary.

Meanwhile, two other men, equally concentrated, push the two lines of fire towards each other; a third walks looking at the ground and extinguishes small fires that insist on following another path with water.

In about 40 minutes, the two fronts meet and, with no more material to burn, they go out by themselves.

The unusual scene is a simulation of controlled burning: a practice used to eliminate organic matter accumulated in the soil and, thus, prevent fires from gaining strength and spreading easily. This type of action can only be legally carried out close to the rainy season, when the soil is still wet, except when exceptionally authorized for training and simulation purposes.

In the reported case, the brigade members demonstrated the work of judicious fire management carried out in the private reserve that is owned by the Boticário Group Foundation. The 8,730-hectare area is located in Cavalcante (GO), a city that has 85% of its territory covered by native remnants of the Cerrado.

The interaction of the cerrado with fire

The biome is considered the most biodiverse savannah in the world – it is estimated that it has more than 12,000 plant species, 4,000 of which are endemic, that is, they only exist there. This variety is due to the multiplicity of landscapes (or phytophysiognomies) that it shelters, such as the typical cerrado (with low trees and bushes), fields (covered by grasses), paths (with humid soil, formed by grasses, bushes and buriti palm trees). ) and gallery forests (forest formations that border streams and small rivers).

Over thousands of years, this vegetation evolved along with the occasional fire, caused by lightning in the rainy season. Thus, not only are species adapted to resist flames, but some need them for their development.

This knowledge is part of the ancestral practices of indigenous peoples and quilombolas, who use punctual burning to clear areas of cultivation, stimulate the regrowth and fruiting of some plants and prevent fires. It is this type of dynamic that integrated fire management (or IFM, as it is known) seeks to reproduce.

“The big issue with integrated fire management is that it is not just prevention management”, explains Alessandra Fidelis, biologist and professor at Unesp (Paulista State University) in Rio Claro who has been researching the effect of fires on the cerrado in the Reserve since 2011. Natural Serra do Tombador.

She claims that preventing and controlling large fires is just one of the fronts of the technique. “The other is cultural: recovering knowledge about the use of fire, which for me is one of the most important parts. The third front is fire ecology”, he says, referring to the study of the relationship between flora and fauna and fires .

In the reserve, she applies different fire regimes to specific patches of herbaceous vegetation (grasses and herbs). Some spots are burned every year, others every two or three years, and others are never burned. The research has not yet been completed, but Fidelis observes some results.

“One of the things we see is in relation to diversity. The plots that don’t burn have a lower diversity”, he says, highlighting that he is only studying the lower vegetation, which makes up the majority of the biome.

Among the studied species, she highlights the herb Bulbostylis paradoxa, popularly known as goat’s beard or Indian hair. The plant is common in South America and, even though it is reduced to charred stumps by the flames, it only blooms on a significant scale with fire: 24 hours after burning, white dots appear that will turn into flowers in less than a week.

Fidelis points out, however, that excessive fire is also a problem. “The big difference between arson and the burnings of traditional and prescribed peoples is the size [da área] that burns all at once”, he says. “The MIF proposal is to burn different areas in different years.”

Cycle break

Allied to the researcher’s work, the MIF was implemented in the natural reserve with trained brigades. “Thanks to this integrated fire management approach, we were able to break the cycle of large fires that we had had in the reserve, which occurred every three years”, says biologist André Zecchin, manager of the reserve.

In public areas, the bodies that can carry out this work are PrevFogo, linked to Ibama (Brazilian Institute for the Environment and Renewable Natural Resources), and ICMBio (Chico Mendes Institute for Biodiversity Conservation), which manages conservation units.

Ane Alencar, coordinator of MapBiomas Fogo and director of science at Ipam (Amazon Environmental Research Institute), explains that the frequency of fires in the cerrado should be determined by natural events, but that, today, a large part of the ignition sources come from pasture areas.

As these fires are often carried out without preventive actions, such as firebreaks (areas where vegetation is cleaned, leaving the ground bare to prevent the fire from spreading), the fire escapes to other areas.

On the other hand, it is also problematic when landlords reduce the occurrence of fire to zero. “The moment a fire occurs in these areas, it ends up becoming a more catastrophic fire”, reinforces Alencar.

A bill is pending in Congress that establishes the National Policy for Integrated Fire Management, which disciplines the use of fire in rural areas and creates intergovernmental instances to manage responses to fires. The idea is that the legislation will allow the technique to be adopted more uniformly in different states.

The fire in 2023

This year, after a longer than expected rainy season, the fires arrived a little later in the cerrado. The fire season, which normally lasts from June to October, only started to gain strength in August, which may indicate that it will end later.

From January to August 2023, 23,631 fires were recorded in the biome, down 16% compared to 2022, according to data from INPE (Brazilian Institute for Space Research). But that number should increase in the coming weeks — especially considering that this is an El Niño year, a phenomenon that brings more heat and tends to produce more forest fires in some regions.

Climate change also influences this dynamic. Recent studies have shown that global warming caused by human activities has already increased the frequency of extreme forest fires by 25% on average and that the annual forest area lost to fire has doubled in the last 20 years.

The reporter traveled at the invitation of Fundação Grupo Boticário.