Expert: Salvage logging reduces erosion |

Expert: Salvage logging reduces erosion

Environmental groups are lining up to oppose Forest Service proposals to salvage log several thousand acres burned by last fall’s Star Fire in Placer County west of Lake Tahoe.

But salvage logging with heavy machinery could dramatically reduce erosion into the American River, said an erosion expert who studied the fire for the Eldorado National Forest.

Wildland hydrologist Michael Kuehn, a retired USFS employee who is now a consultant, said the heavily burned areas are mostly bare ground, and timber harvesting would leave downed logs and debris to trap and hold soil during heavy rains.

Also, the fire baked the soil so much on thousands of acres that it’s become “hydrophobic,” or mostly impermeable to rainfall.

Water gains momentum and carves out rills and gullies when it finally finds a soft spot, removing soil. But tree falling and heavy machinery would break up the soil and make it more absorbent, reducing erosion in a storm, Kuehn said.

He said he saw proof of that after an Oct. 30 rain.

Private timberland burned by the Star Fire and quickly salvage logged had less erosion than adjacent national forest land that hasn’t been logged, Kuehn said.

“The erosion was less, basically seven times less,” said Kuehn, who lives in Camino. “Logging was helping. A timber sale becomes a tool to fix things.”

“It takes about 1,000 years to form an inch-and-a-half of soil” in the area studied, he added.

Once a fire burns away cover, soil can wash away very quickly, he said. Following the Oct. 30 rain on steep slopes on hundreds of acres of unlogged USFS land, Kuehn said an average of a quarter-inch of soil washed away.

Environmentalist Don Jacobson of the Nevada City-based Forest Issues Group disagreed with Kuehn’s take on things.

“There’s no documentation (showing) that you’re going to prevent erosion by logging,” he said. “If you don’t do any logging, (trees and brush) would fall naturally and (prevent) erosion after time.”

Speaking in Grass Valley Saturday, environmentalist Craig Thomas said environmentalists oppose removal of large dead trees, called snags, from the burned-over area because they’re good for wildlife, but take hundreds of years to develop.

The Forest Service proposes leaving at least four dead snags per acre.

Kuehn’s report is included as an appendix in the Eldorado National Forest’s draft environmental impact statement on the Star Fire Restoration.

The fire also burned acreage in Tahoe National Forest; officials there are working on their own, separate environmental impact statement.

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