Prescribed Burns

Using fires to achieve land management objectives
By Patrick White

Nort Phillips (right) and Jim Roberts (left), two owners of Fire Management Services, go over plans with the crew for a prescribed fire.
Photos by Andy Reed unless otherwise noted.

The Smokey Bear character was created in the 1940s, and marketing experts say that Smokey represents one of the most successful and recognizable ad campaigns of all time. Even today, 95 percent of adults recognize Smokey and his message of preventing forest fires.

While it remains as important as ever to warn the public about the dangers of unintentional forest fires, there's also a growing body of scientific evidence showing that, when controlled, fire can actually benefit forests and wildlife. Used in the West to help systematically reduce fuel sources in hopes of preventing large, uncontrolled fires, prescribed burns can also be useful for other purposes here in the Northeast.

As just one example, the Vermont National Guard recently burned 7 acres at Camp Johnson in Colchester in order to help pitch pine regain a competitive edge against other species. In addition to clearing the forest floor and preparing the soil, the heat of the fire also helped release cones from the mature trees above.

Most prescribed fires in this region of the country are conducted by government agencies, most notably the U.S. Forest Service and U.S. Fish and Wildlife Service, on public lands or by conservation groups. However, prescribed fire is also an option for private landowners, says Thomas "Nort" Phillips, co-owner of Fire Management Services, which provides comprehensive "prescribed fire" services throughout the Northeast.

Phillips has 44 years of fire experience, including many decades of service with the U.S. Forest Service as a fire management officer. He started doing prescribed burns in the 1980s. "The first burns we did were for wildlife habitat, mostly upland game birds such as grouse," he explains. Since then, Phillips says there has been increased recognition that prescribed burns can be used for many other purposes as well. "There's a huge number of reasons why a prescribed fire might be an option for a landowner or land manager," he says. It all depends on what the objectives are for the land.

For example, fire can be used to improve the health of lowbush blueberries, which are prized by some landowners who have the plants growing naturally on abandoned farmland with acid soils. "It can improve the vigor of the plant and also kills infestations of the blueberry flea beetle, which defoliates blueberries," explains Phillips. Some landowners with large areas of blueberries also use burns to restore land that hasn't been maintained and is reverting to forest with woody vegetation taking over.

Prescribed fires can be used to accomplish a number of forest management objectives, but they require the right expertise and resources to be safe and successful.

Fire can also be used to help restore abandoned fields. One good approach is to burn the thatch off, which simultaneously provides a free potash treatment for the soil and helps open up the soil for new, healthy grass to invade. Using herbicides on plants such as goldenrod prior to burning, and then mowing any recurrence of those plants after the new grass is growing, can also be beneficial.

Wildlife habitat improvement is another primary area where prescribed fires can play a role. "That's the reason for a good percentage of the prescribed fires that are done in New England," notes Phillips. "There's a huge variety of animals that benefit from the typical upland opening maintenance." This can be done by maintaining rough openings in woodlots, which benefits deer, rabbits and foxes, as well as other animals, he points out.

"Generally, you don't kill everything with a fire, or it resprouts, so you get brush and some trees," he explains. "One of the most desirable - and quickly disappearing - vegetation classes in New England is brush for songbirds. We've gone in and essentially re-established brush by burning the land and getting it to regrow and be more viable."

In certain cases, that maintenance can include some cutting as well as a fire. Phillips says, "A lot of times fire is part of an integrated process. Depending on what a landowner is after, sometimes fire can help you get what you want in one shot. Other times it's part of a process that involves cutting, herbicides and fire." For example, maintaining brush conditions might involve various treatments on a three to five-year cycle, he notes.

Fire can also be used in forested settings. In recent years, Fire Management Services has worked with a number of clients interested in establishing and then maintaining oak understory regeneration. "Oak is fire-adapted," notes Phillips. That means the oak can survive a burn where other species are more likely to be eliminated. "That doesn't mean you won't still have a mixed stand, but other hardwoods have a hard time at that age recovering. And if you don't get the [oak] seedling density or counts that you want, you can go in and re-burn and the oaks will resprout on that root system, so they're more vigorous."

Prescribed fire is one tool that can be used to help shape the composition of a woodlot-controlling beech or favoring oak, for example. However, it takes careful planning to control the fire's height and heat in order to avoid residual stand damage.

He's seen research where areas have been burned up to three times. "That gets to be expensive, but what they've found is that every time they burned, the oak would actually respond quicker; it just gets stronger with fire rather than succumbing to it," says Phillips.

When the goal is to boost oak establishment, the best-case scenario, he points out, is to conduct a burn several years prior to any cutting (harvest, etc.) in that area of the woodlot. That provides time to ensure the desired outcome has been achieved, and for the oak to gain a competitive advantage as a result of the fire. Burning just after a cutting operation offers "mixed results, if not poor success," he reports. "As soon as you open up the stand, competing hardwoods pretty much invade the area, and then the deer browse it, so the oak doesn't grow as fast."

Other burns he's conducted in hardwoods have been to control beech. "We've had success in killing a lot of seedling/sapling beech trees. So if you have a northern hardwood stand and beech is not what you'd like the stand to look like after you cut it, you can go in and control that understory before you cut it and let that sunlight in, so you have fewer of those trees left," he explains. "A fire will get all the little trees, where mechanical methods won't." Young beech are particularly "thin-skinned," and thus are more susceptible to the fire, notes Phillips.

Again, he says the prescribed fire for this purpose should be done well in advance of cutting in order to provide time to gauge the burn's degree of success. Realistically, that isn't always possible, Phillips acknowledges, but for landowners committed to the health of their forest and achieving specific objectives, fire is best used as part of planned stand maintenance programs.

In these types of burns, how do you ensure that the fire doesn't damage the mature trees that are slated for harvest? "That's where the planning and art of prescribed fire come in," says Phillips, noting that each tree has a limit in terms of the flame length and heat pulse that it can tolerate. "So you have to plan the fire, and then pretreat for the expected fire behavior you have on that day."

A trained crew and properly constructed perimeters are essential to keep the fire within the intended boundaries.
Photo by Mike White.

For example, if 2-foot-high flames are needed, the fire will be planned to accomplish that, and a day will be selected where the conditions will limit the intensity of the fire. In addition, sometimes mechanical prep work is done, such as raking around the bottom of seed oak to ensure the fire stays away from those important trees. "The risk of residual stand damage is there, but you try to mitigate it," he says.

In fact, any prescribed fire comes with a lot of upfront planning, Phillips emphasizes. That starts with discussions with landowners to pinpoint the management objectives they're seeking, and then visiting the site to take stock of the situation. Then a list of prefire activities is made. Phillips says landowners can reduce the cost of the project by taking on some of the prep work. Depending on the specific site in question, prep work could include some cutting within the unit to be burned, or bulldozing, raking or leaf blowing to remove sources of fuel on fire lines around the perimeter.

Many landowners like to be involved in the process, including being out on the actual burn, says Phillips. In fact, when possible, he likes to have them light the first part of the fire (under supervision, of course).

Phillips notes that most states require some kind of permit in order to conduct burns, and in some cases formal burn plans must be submitted and approved. "We like to have one anyhow if there's any complexity to the burn," he adds.

Prescribed Fire Resources

Nort Phillips: nort@sover.net

New Hampshire Prescribed Fire Council: http://extension.unh.edu/New-Hampshire-Prescribed-Fire-Council

Sudbury Valley Trustees Prescribed Fire FAQs: http://www.sudburyvalleytrustees.org/firefaqs

Depending on the site and the purpose of the fire, an optimal time of year and weather pattern are determined. "We watch the weather all the time to look for certain weather patterns," says Phillips. The goal is to find the right condition for the technique being used and the objectives of the fire.

Of course, the overriding objective is to make sure the fire stays within the intended boundaries. "The crew we have is very experienced and very competent. People have commented that we make the fire look easy, but I think that's because as a group we know what to expect and know what we can do," says Phillips. "You just have to be attentive and have the resources available." Especially when a hot fire is needed to achieve the intended results, it's not uncommon to have fire cross the perimeter lines in certain spots, but those are quickly addressed, he adds.

Phillips likes to visit burn sites after they've been completed so he can see the results.

"Nothing lasts forever. Fire, like anything else, can give you an effect. But the rewards from that will diminish over time," says Phillips. As with cutting or herbicide treatments, for the best results, fire needs to be a regular maintenance activity. He hopes that more people look at what fire can do and make it one tool in their management plans. "We're in business, but we're also trying to promote the technique, because fire is a way underused management technique for forests in particular," says Phillips.