CompassLive Science Shorts

Mechanical Fuel Reduction Costs

Mulching biomass can change fire risk and nature of the fire. Photo by Mathew Smidt, USFS.

Mitigating wildfire risk is a land management priority across the U.S. Reducing fuel loads through mechanical treatments can control understory and midstory vegetation and prevent fuel ladders that can spread fire from ground vegetation up into the canopy crown.

A book chapter by USDA Forest Service scientists Dana Mitchell and Mathew Smidt summarizes costs, benefits, and limitations for common mechanical fuel treatments.

“Timber harvest can reduce fire risk in overstocked stands or create breaks in fuels across a landscape,” says Mitchell. Plans for burning or spreading logging slash must be factored in with harvest treatments. Income from the harvest can offset some of the costs.

If woody biomass markets are available, baling and bundling can be used to compress small trees and shrubs into residue logs. Without a market, this material would contribute to fuel loading. Whole tree chipping can also generate biomass or biofuel materials.

“We tested the use of mulchers to produce firelines, because this could decrease costs associated with labor,” says Mitchell. “We found wheeled mulchers to be cost competitive with bulldozers on gentle terrain.” Their results suggest that mulchers may be useful for fire suppression in the wildland urban interface.

Read the chapter in Encyclopedia of Wildfires and Wildland-Urban Interface (WUI) Fires. For more information, email Dana Mitchell at