Figure 3. Material flows in the US forest products industry, 1993. Box heights are to scale. All values
in million cubic meters. For paper we consider one metric ton to be equivalent to two cubic meters. a)
Based on the ratio of logging residues (15.1%) and `Other Removals' (6.6%) to all removals for 1991.
b) The dashed lined entering paper represents the inputs from "recycled." We estimate that 100
million cubic meters of the woody mass entering paper mills undergoes combustion for energy. In
1991 the paper industry (SIC 26) generated over 1.2 quadrillion Btu from pulping liquors, chips, and
bark. c) Construction includes millwork such as cabinetry and moldings. `Other' includes industrial
uses such as materials handling, furniture, and transport. d) The ratio of end uses relies on Btu data
from the USDOE Energy Information Administration. The category `Residential and Commercial'
includes Electric Utilities. Sources: Ince 1994; Energy Information Administration 1994; U.S.
Department of Agriculture 1993; U.S. Bureau of the Census 1995; Amer. Forest & Paper Assoc.,
1995; Smith et. al. 1994; and data from the Engineered Wood Products Assoc., Tacoma WA. and the
Western Wood Products Assoc., Portland, OR.