Key Issue -Decaying wood waste releases CO2
Forest biomass components include the canopy (tops and branches), the stem, coarse and fine roots, duff and litter,
snags, dead and down biomass, and organics in the soil.
When wood is harvested and removed from the forest, not all of the carbon flows immediately to the atmosphere. A
stem goes to solid wood products, pulp and paper products. The tops and branches may go to a biomass powerplant for
electricity generation.
Look-up tables have been generated for the above components of forest biomass by tree specie and by geographic area
of the United States. Tables also exist for displaying the growth rates of trees by species, by diameter class, and by age
class by geographic area of the country. Look-up tables have also been developed to “track” the carbon through its live
cycle including decay rates once in a wood product and decay rates for the portion of wood products that end up in a
landfill (both for those with energy capture and those without). Decay rates are also established for tops, limbs, snags,
and dead and down material if it remains in the forest. These are well documented (1996 Birdsey, and Smith, Heath,
Birdsey, Skog, April 2006. “Methods for Calculating Forest Ecosystem and Harvested Carbon with Standard Estimates for
Forest Types of the United States.”)
Carbon life cycle analysis has been demonstrated by several researchers including Dr. Bruce Lippke at the Consortium for
Research on Renewable Industrial Materials (CORRIM) at the University of Washington. The effects of different forest
land management scenarios has been rigorously analyzed and the results displayed graphically:
One caution in observing the “Neutrality Concept” is realizing that effects of disturbances associated with
insects, disease, wildfire, wind events, etc. are not included but, of course, are real factors in unmanaged forests.