After the spring prairie fires are over, the black ground turns to lush green and the cattle begin
grazing. Meanwhile, unburned fields languish as a few green grass shoots remain hidden in the
dead dry grass stems.

–So why is the grass so much more lush in the field on the burned side of the fence?
The contrast is dramatic along a fenceline where one side was burned but the other side was
left “old field.” Any veteran Kansas farmer or rancher can list the reasons:

• Burning brings most of the nutrients in last year’s dead grass down to the black layer on
the ground that then washes into the soil. But nutrients in the dead grass that stands unburned are
still in the air, unavailable to the new grass roots.
• The barren black soil rapidly warms under the sun; but the dead unburned grass shades the
old field, keeping the ground cooler into the spring.
• New blades of grass on the burned area are basking in the sunlight. But the tall dead grass
in the unburned field shades the new grass blades trying to emerge from below.

The increased plant production after burning was obvious to the earliest Kansas farmers and
ranchers. They could see the results in more harvest in crops and beef, even if the actual
measurement of biomass had to await later research.

But whether the fires are man-made prescribed burning each season, or sporadically sparked
by lightening, it is obvious that the grasslands are adapted to fire.

In the photo taken on the Konza Prairie Biological Station, it is obvious how annual burning
has benefited the grass vegetation on the left. The area on the right is only burned every 20 years
and is becoming shrubs and trees.

Plants and animals that thrive under burn conditions are usually “fire positive.” The grass has its
growing tissues, called meristem, down at the ground surface, protected from the overhead
flames. That is why our lawn grass does not die when we cut the tips of the grass leaves when we
mow.

But shrubs and trees grow at their branch tips, and fire kills those growth tissues. Shrubs and
trees are mostly “fire negative.”

Animals are likewise fire-positive, fire-negative or sometimes a combination.

Our state bird, the western meadowlark is dependent on the grasslands and the fire that
maintains the grass vegetation. Fire-positive critters burrow under, slither around, or fly over prairie fires.

Red cedars are among the fire-negative plants. And cedar waxwings that feed on their blue-
coated seeds are fire negative too.

Stop the prairie fires and much of eastern and central Kansas would gradually change from
grasslands to cedar trees.

And the cedar waxwing could become our state bird.

[More information on “Prairie Fires” is available in the Kansas School Naturalist available
free upon request from [email protected].]