Prescribed burning can reduce wildfire risk while supporting the natural health of South Africa’s fire-dependent ecosystems, says Prof Natalia Flores Quiroz of Stellenbosch University’s fire engineering team.
When smoke rises from a planned burn near a town, the reaction is often immediate: Why are they setting fires like that? people ask.
Residents worry that the fire may escape control. Others complain about smoke drifting into homes, schools, vineyards or businesses. To many people, deliberately burning vegetation sounds dangerous and unnecessary.
“But in many South African landscapes, especially where towns meet natural vegetation, fire is not only inevitable, it is necessary,” explains Flores Quiroz.
Hotter conditions mean more fires
South Africa has experienced several devastating wildland-urban interface (WUI) fires in recent years, where fires spread through natural vegetation into communities. The 2017 Knysna fires remain one of the country’s most tragic examples, causing fatalities, mass evacuations, destruction of over 1 000 homes, and enormous environmental and economic losses.
Similar fires continue to threaten communities across the country as hotter, drier conditions and expanding development increase fire risk.
This is where prescribed burning becomes important, says Flores Quiroz.
Controlled fires help curb risk
“The carefully planned and controlled use of fire to reduce accumulated vegetation can play an important role in reducing the risk and intensity of wildfires while also maintaining the health of ecosystems such as fynbos.”
A prescribed burn is conducted under specific weather conditions, by trained crews, with preparation in place to keep the fire within a defined area. Its purpose is to reduce the amount of dry vegetation – or fuel – available to burn during a wildfire.
Importantly, prescribed burning is not only about protecting communities. In ecosystems such as fynbos, fire is a natural and essential process.
Many fynbos species rely on fire to reproduce, with some seeds only germinating after exposure to heat or smoke. Without fire, these ecosystems can become unhealthy and less diverse over time.
“Fynbos typically needs to burn every 10 to 20 years. If vegetation remains unburnt for too long, dead and dry plant material accumulates, creating large fuel loads.”
When fires eventually occur under hot, dry and windy conditions, they can become extremely intense, spread rapidly and overwhelm firefighting efforts.
“In other words, the absence of fire does not remove the risk. It can increase it.”
Forewarned is forearmed
One of the biggest challenges during a wildfire is that fuel conditions cannot easily be changed once the fire has started. Firefighters cannot suddenly remove years of accumulated dry vegetation while flames are approaching homes.
That work needs to happen beforehand.
Prescribed burns can reduce fire intensity, slow fire spread and create safer conditions for firefighting operations. They can also reduce the likelihood of large evacuations, infrastructure damage and prolonged wildfire emergencies.
Temporary inconvenience, reduced hazard
Yet prescribed burns are often unpopular, notes Flores Quiroz.
“Smoke affects nearby communities, while some residents fear that the burn itself may escape control. Municipalities and land managers also face strict regulations, liability concerns, limited resources and very small weather windows suitable for safe burning.”
These concerns are understandable, she says. But the temporary inconvenience of a planned burn needs to be considered against the consequences of an uncontrolled wildfire.
“A few days of smoke from a prescribed burn is very different from weeks of smoke, destruction and emergency response during a major wildfire disaster.”
As more people move into fire-prone landscapes, South Africa will need to become better at living with fire rather than simply trying to prevent it altogether.
Green mountainsides may look safe, but if vegetation has not burnt for decades, those same landscapes can become increasingly hazardous.
“Prescribed burning is not about destroying nature. It is about working with the natural role of fire in our ecosystems while reducing the risks that dangerous wildfires pose to communities,” concludes Flores Quiroz.
Text & Image: SU
