has integrated bioenergy harvesting into their forest management plans (H Baldwin and M Mitzel personal communication). According to SPI management, they do this because the removal of the biomass substantially reduces the costs of other forest operations and reduces the risk and liabilities associated with forest fires.

Many SPI forests in inland northern California are degraded natural ponderosa pine (Pinus ponderosa) stands with a history of high-grading. To regenerate these stands, SPI clearcuts small blocks which are planted with genetically improved seedlings and

managed as even-aged plantations using intensive silviculture. Establishment typically includes ripping and weed control. Since fire is a high risk and carries large liabilities if it spreads to adjacent land, it is important to reduce residual biomass on the site. If bioenergy harvesting were not carried out, the slash would need to be piled and burned, a practice that itself carries considerable risk, causes smoke pollution, and can be safely undertaken only a few days each year. Thus biomass harvesting at clearcutting: