Firefighters responded to the flames that were advancing towards Sequoia National Park’s signature grove of massive, ancient trees on Thursday by setting fire to it.
Firefighters can use the Giant Forest’s nemesis to help stop, slow down or redirect fires by using firing operations.
This tactic is subject to significant risks, especially if the conditions change. It is used routinely to protect communities, homes, or valuable resources now under threat of fires . This includes the grove that contains approximately 2,000 massive sequoias including the General Sherman Tree which is the largest in volume.
Here’s how it works.
It’s all about the FUEL
The terrain, which can make a fire more hot or faster, and the weather (with winds and dry conditions fanning flames), all have an impact on how fast and hot a fire goes.
These two cannot be controlled but you can reduce the fuels well before a fire starts or as it is near.
Maureen Kennedy, a professor of wildfire ecology from the University of Washington, stated that “of all the factors that affect fire behavior,” the fuels are where we can really take action.
Historical fires of low to moderate severity were common every five to thirty years. However, deadly fires occurred in the 20th century. The U.S. Forest Service had a policy to extinguish all fires by 10:00 a.m. on the day they were reported.
This resulted in dense forests of dead trees and fallen logs, as well as overgrown brush, which accumulated over the last century, fueling even larger fires.
FIRE CREATED TO SLOW FIRE
Native Americans have used fire for centuries to thin forests.
When the weather is favorable, prescribed burns can be used to replicate the earlier lower-intensity fires and burn off any excess fuels that are not in danger of becoming out of control. The fire that eventually burns the area will likely be less intense and cause less damage.
It is exactly the same idea during a wildfire. The fire chiefs attempt to use shifting winds and changing landscapes to help the fire get to its destination before it gets started, which can deprive it of the fuel it needs.
Kennedy stated that they are trying to achieve the exact same effect. They’re trying to control the fire behavior. They are trying to get rid of the fuels that cause the fire to burn so intensely. Their goal is to contain the fire better and protect valuable resources.
SAFELY SETTING MILD FIRE
Although all wildland firefighters are taught about firefighting operations during basic training, it is necessary to be trained for planning and carrying out firing operations.
Paul Broyles, an ex-chief of fire operations at the National Park Service, stated that “you need to know how fire is fought before you light fire.”
To burn an area between the firefront and a projected point, such as a Giant Forest in Sequoia or a firebreak, you need the right conditions and enough fire time to complete the burnout.
These operations are often done at night, when fires tend not to slow down or die down as the temperatures drop and humidity rises.
Winds can be drawn in by the convection from a fire, which can make it easier. Burnouts can be set on steep terrain to prevent embers from landing in areas where there are already burnt grasses or brush.
A crew must ensure that the fire doesn’t spread in an unapproved direction during firing operations. This may include air tankers dropping retardant or bulldozers cutting the fire lines.
Broyles stated that all of it must work together.
He said, “Air tankers alone do not put out fires, unless you follow-up with personnel.” It’s just like the military. It’s not enough to bomb your enemy without having ground troops.
Although burnouts are a common method of reducing wind speed or igniting early enough, they can be dangerous.
Rebecca Paterson, Sequoia National Park spokeswoman, stated that “when you put more fire on to the ground, there’s a risk.” It has the potential to cause more problems than it solves.
Broyles stated that there were instances when he couldn’t get a fire started on time, and firefighters had to be evacuated.
He said, “Fortunately, in mine, we didn’t have any losses.”
SMALL FLAMES FOR PROTECTING GIANT SEQUOIAS
Paterson stated that firefighters were performing burnout operations in the Giant Forest on Thursday at a very micro level. They moved from tree to tree. Ground cover and organic debris, known as duff, was being set on fire close to the trees to create a buffer.
To protect themselves from extreme heat, the General Sherman and other large conifers were covered in aluminum blankets.
This park is the first to use prescribed fire in the West more than 50 years ago. It also regularly burns its groves to get rid of fuels. Paterson stated that this was a cause for optimism.
She said, “Hopefully the Giant Forest will emerge unscathed.”