Straw helps forest rise from ashes
September 6, 2003
From an old logging trail on a knoll where the Mount Zirkel Complex fire raged just more than a year ago, the sheer randomness of Mother Nature spills before the eyes.
Corpses of trees remain on the hillsides, burned charcoal and appearing a powdery silver in the noonday sun. Just steps from where the fire burned so hot and so long, it charred patches of earth, green grass, bright yellow arnica and fireweed sprout from the ground. Groves of aspen stand untouched just 20 feet from where fire devoured 200-year-old conifers.
Even as the 30,000-acre Mount Zirkel Complex fire burned, U.S. Forest Service officials wondered what to do about rehabilitating the area.
As the fire dwindled last fall, Forest Service Soil Scientist Tommy John said the federal agency had hoped to begin rehabilitation efforts with aerial straw mulching.
The straw, dropped from helicopters, would provide ground cover that is needed in the most severely burned areas to help prevent erosion. An early October snowfall dashed the Forest Service’s hopes of getting straw down before heavy winter snow.
Fireweed that blossomed this spring was one of the first signs that life had returned in the Zirkel. The hillsides where aflame with it.
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“All the river bottoms were green and lush and already started to rehabilitate themselves. There really was a huge and beautiful crop of fireweed. It is one of the first plants that (comes) back,” Fire Management Officer Mark Cahur said, describing what Forest Service officials found when they returned to the site after the snow melted this year.
But the wildflowers and grasses did not come back everywhere. As the snow melted, dirt and ashes washed away from steep hillsides where only burnt trees remained.
The Lost Dog Creek turned black, John said, carrying some of the forest’s most fertile soil with it.
To prevent a repeat next spring, John put in place the almost $1 million operation of throwing straw on the most severely burnt areas.
Two weeks ago, the mulching process moved into full swing as 135 trucks rolled through Steamboat Springs and traveled dirt Forest Service roads to the Lost Dog Trail. They carried 2,030 tons of straw from as far away as Wyoming and Nebraska.
Seven areas totaling 3,200 acres were identified for aerial mulching. The Mount Zirkel Wilderness area was left untouched.
The straw keeps the ground surface moist, John said. It also protects the surface from the impact of raindrops and reduces erosion.
“It gives it 60 to 70 percent ground cover. The erosion rates go way down, almost to pre-burn,” John said.
Straw was dropped on the most severely burned areas, where the fire scalded the soil, making vegetation growth this year unlikely. Not only did the fire destroy plant life, John said, it left a waxlike water repellent on the ground’s surface, making it hard for moisture to seep into the earth.
The straw did not go on the areas where the fire leaped through treetops, leaving the ground cover intact, or in the water basin, which already is healthy and green.
On Thursday morning, two helicopters whirled above the largest of the charred areas the Forest Service is attempting to rehabilitate. They started the aerial mulching Monday and had two days to finish the project. The Bell 2-14 and Sikorsky helicopters covered two sections of the 1,700-acre unit near the Lost Dog Creek and English Creek areas.
Spreading the straw on the ground began with putting between 700 and 2,000 tons of straw in a large cable net attached to the helicopter by a 65-foot cable.
The helicopters flew above their targets until they reached the right height and speed — about 100 feet above the ground and 90 mph — and then released the cargo net, sending clumps of straw plummeting to the ground.
Ground crews of four to five people had only a few minutes to place the next loads of straw into other cargo nets before the helicopters returned.
About 20 people are involved in the aerial mulching process. The Forest Service has four or five people watching as the straw drops, making sure it is spread out over the ground evenly and the right spots are being hit.
One helicopter load covers 2 to 4 acres. If done on the ground, John said, the mulching could take months and many of the places targeted for mulching would be too difficult to reach.
The Forest Service has been doing aerial mulching for the past five years, John said. It was used on the 138,000-acre Hayman fire that burned Colorado’s Front Range last summer, as well as on burned areas in Arizona and Oregon.
The Forest Service took the contract for aerial mulching after the Hayman fire and changed it to meet the needs in the Zirkel area, John said.
Other rehabilitation work has gone on throughout the Mount Zirkel area. Cohur said watershed and trail work have been done on existing roads and trails. He said the Forest Service will be constantly monitoring the area.
Even with the rehabilitation efforts, it will take hundreds of years for the forest to return to how it looked before the fires occurred.
The old-growth forests in the Mount Zirkel area have been in rapid change since the 1997 Blowdown, in which a microburst windstorm turned hundreds of acres of massive trees on their sides. The dead trees were first attractive targets for the beetle epidemic and then for last year’s fires.
“It is really an amazing transition,” Cohur said.
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