46 Nebraskaland • May 2024
t happened slowly. Eastern red cedar trees were once
found only in steep, moist corners of the landscape, rocky
hilltops or islands in rivers where they were protected
from the fi res set by Native Americans to attract game or
sparked by lightning that periodically swept across the Great
Plains. When settlers arrived and fi re was removed from the
equation, this opportunistic invader began to creep out of
its refuges and into the surrounding grasslands. Each year,
cedars consumed more valuable grazing land and wildlife
habitat. The front line advanced so slowly it has been dubbed
the green glacier.
Now, after more than a century without these periodic
fi res, the prairies are one of the most imperiled and least
conserved ecosystems in North America. Across the Great
Plains, from Texas to the Dakotas, woody plants including
cedars are expanding at a rate of 10 percent per year. Where
the problem is at its worst, grasslands are now dense
woodlands. Nebraska has lost 500,000 acres, or 781 square
miles, of grassland since 2000 alone. That's nearly the size of
Lancaster County.
Eff orts to control cedars are many and growing, but the
problem is so bad, cedars are still winning the battle. In the
Loess Canyons region of southwestern Nebraska, however,
landowners are making serious headway. The key to their
success has been working with their neighbors to reintroduce
fi re. With large, intense prescribed burns, they are killing
trees from the ridgetop prairies, down the steep slopes and
into the canyon bottoms. It is one of few places in the world
where the rate of woody encroachment has been stopped.
Soon, it may even be reversed.
With fi re, they are melting the glacier.
The Problem
The Loess Canyons region encompasses a 330,000-acre
triangle of land south of the Platte River between North
Platte, Cozad and Curtis. The region's present topography
is related to its origin. At the end of the last glacial period,
wind slowly blanked the area in loess, tiny particles of silt,
clay and sand. Among the thickest such deposits in North
America, the loess is highly erodible. It has evolved into a
maze of steep-walled canyons that stretch like veins from
the main creek draws, some leading north to the Platte
River Valley and most south to the Republican River Valley.
Cloaked in mixed-grass prairie, the canyons contain grasses
Melting
the Green
Glacier
Story and photos by Eric Fowler
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