As a newcomer to the state 30 years ago, I spotted my first prairie fire in Kansas and breathed relief when I saw there were people nearby. As I drove closer, I saw they weren’t putting it out!
They were deliberately setting the fire!
Like most people, I assumed that prairie fires are bad. Like most people, I was wrong.
This is the season for controlled burns in the Flint Hills.
Before settlers came to Kansas, the Osage and Kansa Indians fired the dead grass to lure in the bison and deer to the new green pastures.
Before that, nature lit the grasslands with lightning.
The prairies would burn from river valley to river valley.
The Flint Hills would not remain grassland without the fires.
There is enough rainfall in eastern Kansas to grow shrubs and even forests.
But grass is here because it is adapted to fire. The growing tissue, is down at the base of the grass and is unharmed by the brief burn, just as grass is unharmed by lawn mowing. Trees and shrubs have their growing tissues out at the tips. And when the fire burns the twigs, it kills the trees. If there is only a year of dead grass for fuel, and a gentle breeze to move the fire along, the fireline burns cool. You can sometimes even step over it. The grass survives and is ready to sprout up within days.
This is easily seen along a fenceline a couple of weeks later. On one side the prairie has been burned, and on the other last year’s dead grass remains. On the unburned side, the dead stalks withhold the nutrients and shade the ground, denying the new grass light to grow. The shaded ground is cool; the grass emerges late and it is sparse.
Over on the burned side, nutrients are now washed into the ground. The black soil is warm. The grass grows sooner. And the full sunlight produces a far richer, greener field.
And what about the animals? The deer and bison merely run away from spring burns, and they don’t bear their young during this time. Among the prairie-nesting birds only Henslow’s sparrow is impacted by fire; most birds are adapted to the effects of prairie burning. Prairie voles and cotton rats have leafy nests at the surface, and their numbers go down. The deer mouse, pocket mouse, and small ground squirrel eat seeds and insects, and they benefit from the fires. Fire obviously kills some animals that cannot escape, such as some turtles and other reptiles. But the number of underground critters increases with fire.
Around here, several ranchers often cooperate in a pasture burn; they call it “neighboring.” After looking at the weather forecast, a rancher picks the best day, place, and time. Burning is best with warm temperatures and a recent rain...so the new grass will spring up quickly. A mild wind needs to be blowing, and in the right direction. No wind at all, added to dry conditions, makes for a slow intense burn. That damages both the grass and the fence posts.
Today science knows what Native Americans knew long before settlers arrived: prairies depend on fire.
If we didn’t burn the prairies, Kansas would soon become the red cedar state.
After 30 years of living in Kansas, I look forward to the light haze and the sweet smell of the annual spring burn. And I don’t look for the fire trucks...anymore.
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John Richard Schrock trains biology teachers and lives in Emporia.
