Conservation Currents

Discussing Biomass

November 2010

By Shelly Stiles

The Beaver Wood proposal for a biomass-based electrical generating facility in Pownal has generated a lot of heat but, in terms of the biomass question, not much light.

For starters, what is “biomass,” anyway?

To the scientist in her laboratory, biomass is defined as everything now or once alive. To the forester, however, or the logger, the wood products buyer, or the firewood supplier – that is, anyone who makes a living working the forested landscape – biomass is usually low value, traditionally non-marketable woody material. It is not sawlogs, pulp wood, or firewood. It is whatever is left – small diameter trees, ailing trees, logging slash, and otherwise non-marketable material.

And there’s a lot of it in these parts.

According to Paul Frederick, Wood Utilization Forester with the Vermont Department of Forests, Parks and Recreation, Vermont grows but does not harvest 700,000 green tons of net available low grade wood, or biomass, annually. (Net available wood is wood you can get to, that isn’t growing on a sensitive site, and that is owned by a landowner who may be amenable to logging it.)

How does that compare to demand? In 2008, says Frederick, the state’s entire wood chip harvest totaled 17,000 green tons of low grade wood. In general, Vermont and adjacent New York, Massachusetts, and New Hampshire can supply more biomass than we can use now and for some time to come. More specifically, a recent computer model created by the Biomass Energy Resource Center (BERC), a national nonprofit research organization dedicated to developing sustainable biomass energy systems at a community scale, tested the impact of a hypothetical 20 MW wood-fired power plant on Bennington County’s forest resources. It found no significant impact on the inventory of net available low grade wood.

This present and future excess of supply over demand means our forests won’t be stripped bare anytime soon. In fact, the harvest of low grade wood or biomass is now almost entirely a byproduct of the harvest of sawlogs, pulp wood, and firewood. Mike Snyder, Chittenden County forester, says that it seems the wood-fired McNeil Station in Burlington doesn’t drive the harvest of low-grade wood, but sometimes makes other work in the woods more economically viable. Indeed, BERC’s 2007 Vermont Wood Fuel Supply Study recommends supporting strong markets for high-grade and mid-grade forest products to help make low-grade wood harvesting – a marginally profitable activity at best – economically feasible.

Finally, increased low-grade wood harvesting can provide many benefits beyond those related to renewable energy and its impact on our long-term carbon budget.

The harvesting and subsequent use of biomass can help maintain existing working landscape jobs and create new ones. The BERC study found that the average age of loggers in our region is forty-five. Increased demand generated by new markets can encourage young folks to take up a forest-related profession. Equipment suppliers, year-round chipping yards, storage and processing sites, and new commercial lending programs will add their own employees to the wood products industry.

Having a viable market for biomass can help landowners pay for forest management activities that improve tree growth, enhance regeneration, control invasive plants and insects, protect water quality, and manage for wildlife.

Eighty percent of the forest land in the state is privately owned, and most of those landowners depend on proceeds from their harvests to finance their forest stewardship activities. In fact, without occasional income from harvest operations – including the harvest of low grade wood for biomass – forest landowners could be forced to develop their lands. Good forest management protects the ecological functions those lands provide, and helps keeps forests forests.

Shelly Stiles is the district manager of the Bennington County Conservation District and a member of the Bennington County Sustainable Forest Consortium.