The following is
from:http://www.ornl.gov/ORNLReview/rev28_2/text/bio.htm Top:
Growing forest accumulates carbon until it achieves, over time,
a balance between the carbon taken up in photosynthesis and the
carbon released back to the atmosphere from respiration,
oxidation of dead organic matter, and fires and pests. In the
meantime, fossil fuels are used to meet society's energy needs.
Bottom: In productive forests, trees can be harvested for use in
producing heat or power. Although harvesting may result in less
carbon stored in standing biomass and forest soils, biomass
fuels replace some of the fossil fuel that would otherwise be
burned. The carbon in that fossil fuel remains stored in the
ground rather than being released to the atmosphere. In both
scenarios there are some energy needs for gathering the resource
and converting it into useful energy, but, as the arrows on the
transportation system suggest here, these are generally
comparatively small. Arrows provide a qualitative indication of
the magnitud