Picture this – it’s July and the temperatures are in the high 90s. Weeds and grasses are mature. You see smoke on a hill in the distance – smoke means fire.
You worry because prairie fires can get out of hand and threaten nearby structures. Then, you learn the fire is being deliberately set by a federal agency.
Why would someone deliberately set a fire? Prescribed fires serve many purposes including reduction of invasive species, improve wildlife habitat, reduction of wildfire risk, support for a healthy prairie ecosystem and drought resilience. Prescribed fires take a lot of planning and training to accomplish properly. Staff at the U.S. Army Corps of Engineers in the Kansas City District use this tool regularly for those reasons.
So, how does setting a fire help a drought?
Using prescribed fires to decrease invasive species populations and promote drought resilience may sound contradictory, but oftentimes these burns control plants such as eastern red cedar, salt cedar and phragmites, which are “thirsty” plants. These “thirsty” plants have root systems that rob the soil of nutrients and drink up more than their fair share of water. They also shade, smother and outcompete native plants.
Fire is a natural treatment that mother nature and indigenous people have been using for many years to conserve lands, according to the Fish and Wildlife Service’s webpage.
“Over the last 180 years, roughly, we’ve been suppressing fire in the ecosystems,” said Ryan Williams, who is a natural resource manager at Kanopolis Lake with USACE Kansas City District. “We’ve had this mentality that “fire” is bad, but if you look back to when we settled this area, fire on the area was set by mother nature through things like lightning strikes, and those fires would run until something like a river stopped it. That is what we are doing, just on prescribed scale.”
Additionally, managing the fires when the air temperature is warmer means that it takes less intense fires to heat the plants to a temperature that kills the invasive plant species. Fire intensity affects a plant’s response to fire and is often used in managing woody species such as the woody cedars and phragmites, Williams explained.
According to Wilson Lake Natural Resource Manager Nolan Fisher, “In some places, we will see water the next day after 30 years of no water because the fire killed off the water draw from so many invasive trees.”
Other benefits include wildlife habitat being enhanced and plant life returning quickly.
“Prairie plants recover faster so you’ll see sprouts within days, and with the invasive plants no longer robbing the soils of precious water and space, it often takes less than a year for the native prairie grasses to regain hold,” said Williams.
This is important because the unbroken tall grass prairie that once dominated the American landscape now makes up less than 4% of the U.S. ecosystem.
Prairie grasses are also less “thirsty” and can return ahead of the invasive plants, which helps contribute to drought resilience.
The prescribed fires are not necessarily required every year and are more environmentally friendly than mowing or clearing and grubbing operations.
USACE also leases land to support selective grazing and hay cutting, which offers another solution that is similar to what the landscape experienced when large bison herds grazed the prairie prior to early settlements.
Treatments that mimic the natural processes, like prescribed fires and selective grazing, are the most effective land management tools USACE staff have to conserve public lands.