To understand the interest in biomass, you've first got to understand what biomass is.

"We used to call it old punky logs, then woody debris, slash, fire hazard, tops and limbs," said Elaine Oneil, a University of Washington research scientist and speaker at this week's Forests and Energy Conference at the University of Montana. "We keep changing the name, depending on what we intend to do with it."

You've also got to know what biomass is not, at least in Montana. It's not corn-based ethanol fuel or switchgrass. It might be forest wood fiber that's burned for electricity, or distilled for liquid fuel. It might or might not be eligible for federal research or energy efficiency subsidies.

"It's a game-changer," Oneil said. "We're trying to integrate it into all the other uses we have for forests. And climate change will fundamentally alter the structure of our forests. We can grab this opportunity to use these materials and reduce our carbon footprint, or we can allow it to burn and enter the atmosphere once again."

This week's conference looks at the economic and ecological aspects of turning biomass into a commodity, especially for energy production. UM interim Dean of Forestry and Conservation Jim Burchfield said that by the end of the three-day gathering, he hopes to have some policy ideas that could direct how Montana handles this potential new resource.

A number of challenges remain. U.S. Forest Service researcher Robert Rummer said federal policy can have a huge impact on the kinds of investment people are willing to make in the infant area of biomass energy. And each part of the country has different opportunities and limitations.

In Montana's case, dry slow-growing forests could benefit from removal of slash wood because it reduces the wildfire danger. But it may not be able to produce the quantities of material needed to economically compete against petroleum- and coal-based power sources.

Environmentalists also caution that removal of biomass could have serious consequences for the plants and animals that depend on fallen trees. Oneil acknowledged that calculations must be made separately for each forest area, to ensure that enough material is kept in place for the local ecology to thrive.

Add to that the limitations on private, state and federal forest lands that could be harvested for biomass, the cyclical nature of wood harvest that traditionally works in single years rather than the 7- to 10-year time frame of utility power contracts, and the constantly changing markets for coal and oil - and the whole biomass picture gets as bushy as a dog-hair lodgepole pine forest.

But that could change within a year, Rummer said, as the national debate on alternative energy nears resolution.

"The key point is this is a potentially great tool for management of the nation's forests," he said.

Reporter Rob Chaney can be reached at 523-5382 or at rchaney@missoulian.com.