It’s a fine spring morning. You are driving to one of your favorite trailheads in anticipation of a hike when all of a sudden you see smoke rising from the woods in the direction you are headed. As you get closer you pass a sign. It reads: Prescribed Burn—Do Not Report. Ahead a bit further you see wildland firefighters clad in bright yellow shirts laden down with tools, packs, and helmets. Several are carrying cans from which a stream of fire seems to pour forth. Minutes later a wall of fire, chest high creeps through the trees consuming the underbrush. Welcome to forest management.
Fire is typically thought of as a bad thing. Generations of Americans have grown up being warned by a bear that wears jeans and a ranger hat and who carries a shovel that forest fires must be prevented. While Smokey has a point, we obviously don’t want stands of valuable timber and sensitive habitat areas to go up in flames, fire is a natural part of the forest life-cycle. As man has encroached further into the wild, the need to protect property and lives has been put ahead of the biological needs of the forest, so wildfire is usually suppressed. As time goes on and fire is not allowed, more and more fuel accumulates in the woods and eventually it becomes a hazard. Setting a managed fire is one tool foresters use to eliminate accumulated dead wood and reduce the risk of it burning out of control and doing more damage.
Far away from developed areas, fire is also employed as tool for forest regeneration. Under very precise conditions the heat and flame length of a fire can be used to eliminate certain types of vegetation that is stunting the development of other preferred tree species. For instance, a tract of land where foresters wish to grow more oak trees might be burned to eliminate heavy birch growth. Oak is a much more desirable tree because it has a higher value for timber sales and it also produces more food for wildlife. Fire will affect birch trees differently than it will the oak, so an area that was once timbered or destroyed by insects such as gypsy moths might be regenerating more birch than oak. Once birch is reduced, oaks will have a better chance to grow and repopulate the area.
Regardless of the intended use, preparation for a prescribed burn begins months in advance. In almost every case, experienced foresters begin the process by evaluating the land to be scorched and then draft a detailed plan concerning the objectives, precautions, and cost effectiveness of the project. Once a plan is drafted it is sent to for approval by the land management agency that has jurisdiction over the area. If approved, crews get to work weeks before any torch is lit.
Prior to the fire, saw crews fall dangerous dead trees around the perimeter of the fire zone and sometimes even inside the area to be burned, less they fall outside the area or drop on a firefighter working the blaze. If there are no natural barriers or roads to contain the fire, heavy equipment may be employed to create a fire break, thus containing the fire to its designated area. Once firefighting assets are put in place and if the weather and conditions are correct, then a highly trained firefighter specifically certified to supervise the mission will begin the burn.
If all goes as planned, the firefighters assigned to the burn really won’t have much to do except make sure the fire is contained to the defined zone. Brush trucks and water tankers are on standby to put out spot fires that may jump the established lines but generally the main fire is stopped through the means of a backfire, another fire set in the opposite direction of the main blaze that devours the downed wood in the path of the original fire. Once the two meet they burn each other out. Typically all that is left to do then is mop up the area by extinguishing smoldering stumps and falling hazardous trees that were not consumed in the flames. Since all the methods used to prepare and execute the prescribed burn are firefighting techniques, fires such as these provide valuable training wildland firefighters need when attacking an uncontrolled conflagration.
It may take years to see the results of a fire used for forest regeneration, but when set to eliminate hazardous fuels, the fire effects can be seen almost immediately. While neither the Lackawanna nor Delaware State Forests have any prescribed burns on their agendas for this year, the Delaware State Forest led the state in prescribed acres burned in 2013. However, other agencies and organizations such as the Pennsylvania Game Commission, the National Park Service, and the Nature Conservancy do have plans for fires this year in Northeastern Pennsylvania, so don’t be surprised if you happen to encounter one going on in the near future.