Researchers Tame Fire to Enable Precision Burning in Forests

Forest research doesn’t get more spectacular than what’s happening in Hagestad Nature Reserve in Österlen, Sweden. Large flames lick the oaks as a 150-square-meter plot is burned. Smoke swirls and stings the eyes of those fire monitors not wearing protective masks. A drone buzzes overhead like an angry insect. Steam rises from the charred heather and grass. PhD-student Olga Wepryk films with her phone and calls out temperatures, wind speeds, and the fire’s intensity and height.

“This was the first large plot. Previously, I’ve burned around 120 plots that were a third the size of this one,” she says.

Firebreaks are cut around the area

Burning within a nature reserve naturally requires both permits and safety measures before Olga Wepryk ignites the propane torch and sets fire to the dry heather and grass. Around the area to be burned, vegetation is cleared to create a sandy firebreak. The perimeter is thoroughly watered with watering cans. When the fire is lit, students stand by with fire beaters, ready to extinguish any flames that try to escape.

The research also requires extensive preparation. Plant samples are taken from the ground. Thermometers with long cables are laid out. Wires are set up to measure the flame height. After the burn, new samples are taken from the scorched soil.

“We’ve also placed temperature loggers on the oaks to see how the heat affects them. We’ll come back in the coming years to monitor their vitality.”

Seeking precise fire behavior data

The researchers in Hagestad are studying fire behavior in detail. They aim to understand exactly how fires behave depending on the type of fuel present and weather conditions.

“Knowledge varies widely between different regions and forest types. Here in southern Sweden, we actually know very little about the specifics of fire behavior,” says Igor Drobyshev.

Better understanding of fire dynamics in the forest could make conservation burning a more commonly used tool in forestry. It could be conducted with much greater precision and across larger areas.

“Fire can be used as a tool to maintain biodiversity, to preserve natural forest types and natural processes that we’ve completely lost in modern forestry.”

Improved fire risk forecasts

The research findings could also lead to better fire risk predictions—and better forecasts of how fires might spread once they’ve already started, including how quickly they move under specific conditions.

“That’s hugely important once a fire is underway. To know whether it’s safe to send people in and take action—or whether it might be better to wait,” says Igor Drobyshev.