Burning for good: How New Hampshire ecosystems benefit from prescribed burns

This article is the second in a two-part series looking at restorative uses of fire around the state. Part one is about how Indigenous people are working with the Forest Service to return fire to the landscape.

On the morning of the burn, the nerves set in. Even months of planning doesn’t guarantee that the weather conditions will be just right. The team starts with a small fire, watching the flame to determine whether they can proceed.  

For Heidi Holman, the start of a prescribed burn is unnerving even with her years of experience. Holman is a wildlife biologist with New Hampshire’s Department of Fish and Game who has been using prescribed burns to support ecosystems throughout the state that depend on fire to survive.

Species like the Karner blue butterfly, the frosted elfin butterfly, and the roseate tern hang in the balance, as do rare habitats like the pine barrens. That’s why this fall Holman and her team have planned a series of prescribed burns around the state – setting small, controlled fires on the Isle of Shoals, a group of islands about 7 miles offshore in the Atlantic Ocean, and on the pine barrens surrounding Concord’s airport.

These fires also help eliminate shrubs and downed branches that can fuel wildfires.

During a prescribed burn, the team will burn anywhere from 2 to 15 acres of land. At least six to eight people participate in each burn, but sometimes as many as 15 are on site. The burns can last anywhere from 40 minutes to four hours, depending on the wind and whether the path of the burn is straight or requires the team to make a lot of turns.

“You’re very nervous and (full of) excited stress that morning,” Holman said. “And then as it starts to progress, and you’re laying more of that fire down, it creates black.”

Black is good because it means there’s no more vegetation to burn; it creates a safe zone. “As you get more black on the ground, you begin to feel a little bit better,” Holman said. “You know that your edges are secure and you may begin laying more fire, and the rhythm starts to happen.”

Holman said prescribed burns are critical to the survival of the Karner blue butterfly. Wild lupine is the butterfly’s host plant, which allows it to complete its caterpillar life stage and become an adult. But without fire, trees encroach on these open fields, casting shade on the lupine and killing it off.

“Prescribed fire just maintains those openings and it also gives this flush of nutrients,” she said. After a fire year, butterfly populations boom because there are more nutrients available to lupine, which means better nutrition for the caterpillars eating the lupine. When the caterpillars become adults, they, in turn, lay more eggs.

Beyond these established benefits, Holman believes fire is important to that ecosystem for reasons that science has yet to fully understand, including its role in nutrient cycling or its impact on a kind of bacteria that grows on lupine that may be critical in how it competes with other plants. These relationships haven’t been studied or understood, Holman said, “and so it’s easier to just sort of mimic a natural process and hope all of that happens.”

“These systems support so many other unique species that we haven’t even had the capacity to begin researching,” she said. “Imagine the relationships.”

Pine barrens are a unique habitat, like an archipelago spread across the region; other barrens are found in coastal Maine, Cape Cod, Massachusetts, and Albany, New York. In Concord, Holman has been told that the sand is anywhere from 60 to 80 feet deep. It’s nutrient poor and porous, so water flushes right through it, creating a hot and dry environment where fire can easily occur. Fires would occur naturally here but are prevented because of nearby homes.

Steve Sherman, the chief of the Forest Protection Bureau at the New Hampshire Division of Forest and Lands, works with Holman’s team on prescribed burns.

“I’ve been with the state since 1997, and we’ve been burning since then and since before then,” he said. 

Wildfires have been worse than usual this summer because of drought conditions throughout the state, and prescribed burns can help with that, too..

“We are alleviating the potential for large, out-of-control wildfires by having these smaller, controlled fires,” Holman said. “Once that fuel’s done, that catastrophic, big fire is less likely to occur.”

She said large wildfires occurred in Concord up until the 1980s in the area by the Steeplegate Mall.

But fear of wildfires can prejudice people against any kind of fire, even if it’s beneficial. Holman said in her experience residents have been understanding, and she thinks most people are used to the fires. “Everyone’s aware. They’ve been getting the message for 20 years,” she said. “We try to keep burning so that our presence is known.”

A prescribed burn ends after the team ensures all of the fire is completely extinguished. It can take around an hour to walk through the burn and check for any remaining hotspots. 

The blackened ground seems devoid of life, but in its wake the fire has left the exact conditions required to sustain it.