Accomplishing Forest Restoration with Biomass Harvesting Methods

Eagle Lake Ranger District
Lassen National Forest

Biomass Harvest Operations

The term "biomass" is used to denote the use of wood as a continuous renewable resource that can be used as a fuel to generate electric power and other forms of energy products. The primary source for biomass on the Eagle Lake RD are conifer trees that range is size from 3 inches dbh to 9.9 inches dbh. The primary product of biomass operations mostly consists of small, low value trees, biomass operations operate on very thin profit margins. In successful biomass operations low profit margins are mitigated by increased production during harvest operations. Thus there is a need to mechanize the operations.

EP2 - Pine stand marked prior to shearing operations

This photograph represents a typical, overstocked, eastside pine stand on the District, which has been marked for biomass thinning harvest operations. The objective of this thinning is to create a fuel break called a defensible fuel profile zone or DFPZ. All trees 3" dbh and larger not designated with yellow paint will be removed from the stand.

Operations

Shearing
The conventional logging practice of hand felling trees with a chainsaw is not practical or economical in biomass harvest operations. Mechanical equipment like the self-leveling feller buncher in the photograph above are needed to shear or cut the trees and place them in bundles for removal by the skidding operations.

Skidding
Once the trees are sheared and bundled by the feller buncher, they are hauled or skidded to a designated landing or processing area. In the photograph above, a rubber tire grapple skidder is "skidding" a sheared and bundled pile of primarily small trees to be chipped or processed into small sawlogs.

Processing
Once the bundles of trees reach the landing, they are segregated into two different processing piles. One pile will consist of trees that will be manufactured into small sawlogs, which are trees that are 10 inches or larger at dbh, and the other pile will consist of smaller trees that will be chipped for biomass production. This photograph represents a stroke delimber which is processing the trees into small logs. Note the pile of sawlog tops and smaller biomass trees behind the delimber that are piled for chipping after the sawlog operation has been completed.

Chipping
This photograph shows a whole tree chipper loading a typical chip van with chips. Each chip van can hold 25 green tons or 50,000 pounds of chips. A typical chip van can carry enough fuel to produce 12 megawatt hours of electricity, or enough fuel to generate the electrical needs for 1,000 households for twelve hours.