Forest thinnings could provide resources for power, fuels

By Nicholas Zeman
Firefighting costs, combined with habitat losses, are some of the dangerous consequences associated with forest density, and many U.S. woodlands are unhealthy from being overstocked. If the clearing of problematic stands occurred more frequently, however, major volumes of biomass would be available for various applications.

The U.S. Forest Service is touting ethanol as the best solution for the utilization of cleared biomass like small-diameter trees and underbrush, and U.S. Forest Service Chief Abigail Kimbell recently proposed replacing 15 percent of the nation's gasoline with ethanol derived from such feedstocks. Kimbell, who assumed the lead position in February, formerly worked as associate deputy chief for the National Forest System in Washington, a state with 9.2 million acres of public forestland and one of the leading lumber producers in the United States.

Bruce Lippke, a University of Washington professor in the College of Forest Resources, told Biomass Magazine that Kimbell's goal will be difficult to meet, however. "It's certainly not going to happen in the short term, and considering the history of federal management, it's pretty doubtful," he said. "The infrastructure has imploded as the harvest has decreased, so paying to remove this material once it's cleared is not economical."

In addition, the best methods of collecting and converting forest thinnings to fuel or power is still being developed. "Is ethanol the best route?" Lippke rhetorically asked. "This issue is still in the research realm. Some cruder form of gasification might be the most efficient."

Lippke said wooded areas in Washington are currently twice as dense as before Europeans first inhabited North America, and efforts to clear these areas are considerably lacking at the present time. "We aren't even close to doing enough," he said.