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| Members of the Fort Knox Fire Department, Natural Resources Branch and installation game warden Lt. Jon Ash discuss how they plan to conduct the prescribed burn at Brumfield Range Road March 18, 2019. Natural Resources Branch chief and wildlife biologist Mike Brandenburg said a lot of planning goes into each burn. |
FORT KNOX, KY, UNITED STATES
03.21.2019
Story by Eric Pilgrim
Fort Knox
After months of historic rainfall totals in central Kentucky, members of Fort Knox’s Natural Resources Branch, assisted by the Fort Knox Fire Department, were recently able to get out and conduct prescribed burns in selected areas.
The Natural Resources Branch chief and wildlife biologist, Mike Brandenburg, led a small team of experts to a 128-acre area along Brumfield Range Road March 18, where they attempted to reclaim some grassland that has been overgrown by several trees and bushes.
“The purpose of this burn, in particular, is primarily ecological management,” said Brandenburg. “What we have going on in this unit is, it’s a timber harvest area where we harvested cedars out of it but it’s not a very beneficial habitat. We’re trying to convert that back to an earlier successional stage habitat in part of it — an old field or grassland. This habitat type is much more beneficial to many of the species of wildlife that inhabit Fort Knox than the cedar thicket that was there.
“The other part of it is that fire, depending on the intensity of it, is beneficial to a lot of the forest species that we’re managing for; oak and hickory in particular.”
Brandenburg said some species of trees actually benefit from fire because they are fire tolerant. Whereas maple trees, sassafras and other species that natural resources specialists don’t want in the forest are not.
“A little bit of fire application can remove those species from the stand and select for oak and hickory. This is the forest type that is ecologically and economically the most valuable in our region,” said Brandenburg.
The land they targeted March 18 had groves of juniper, what Brandenburg called eastern red cedar. The trees grow close together and drop their needles below a dense shady coverage, which chokes out ground fire. As a result, the crew struggled in those areas to maintain a satisfactory fire. In the low-lying area of the unit, soaked land and sparse ground cover thwarted efforts to burn out the unwanted species.
“Prescribed fire is the most important habitat management tool that we have available to us and is important to all of our habitat types in differing intervals and intensities,” said Brandenburg. “It is also often used on the installation to maintain line of sight on ranges as well as to consume fuels during moderate burning conditions, and reduce the chances of severe wildfire outbreaks.”
Brandenburg explained that a lot of science and planning goes into each prescribed burn. Such factors as wind speeds and direction, temperatures, relative humidity, fuel loading, species types, smoke dissipation and burn location are taken into account before the decision is made to go in.
Safety is also critical before and during a burn.
Grass, bushes, trees and any other flammables in the woods are called fuels by Brandenburg. He said fire practitioners categorize them as one-hour fuels, 10-hour fuels, 100-hour fuels and 1,000-hour fuels, referencing how long it takes for their moisture levels to change due to environmental factors. Fire will or will not consume an area based on one of these categories. The one-hour fuels category, for instance, is defined as fuels that are ¼ inch or less in diameter, such as grasses, shrubs and leaves. Those are the basis for carrying a fire and achieving many of the burn objectives.
On March 18, the crew had on hand two all-terrain vehicles with 75-gallon pumpers mounted on each, a truck with a 300-gallon pumper and a bulldozer, as well as hand tools for stamping out small embers. Brandenburg said the winds and temperature seemed perfect for a prescribed burn.
“When we’re out here, we’ll focus on not watching the fire as much as watching where the fire is not in order to identify any spot where fire has left the prescribed area,” said Brandenburg.
He explained the fire can jump a fire break, such as a road or already burned area, if fuel levels coupled with wind levels are high enough. Because of this, they usually position water capabilities along the perimeter downwind of the fire to quickly react in those situations.
Another area of consideration is the weather.
“We’ll think about not only what the weather is doing today, but what it’s going to be doing when we’re expecting to still have residual smoke,” said Brandenburg. “Sometimes we might go burn a spot, knowing that we’re going to get rain in a certain period of time. That helps to reduce concerns about residual smoke impacting smoke sensitive areas.
“There’s a lot that goes into implementing one of these burns.”
