TIMBER VOLUME 



The estimate of timber volume in trees 11,0 inches d.b.h. and larger 

 of all species is 14.9 billion board feet by International 1/4" rule. 

 Approximately 80 percent of this volume is in saw-timber stands, 16 

 percent in pole stands, and 2 percent each in seedling- sapling and 

 deforested areas. Although the estimate is approximately 3 percent 

 greater than the 1935 estimate the difference is well within the 

 sampling error limits. Disregarding the volume on deforested areas 

 for which no volume was estimated in the 1935 survey the difference 

 is less than 1 percent. In spite of the fact that the all-species 

 volume remained practically unchanged, there was a notable decrease 

 in the volume of white pine, the most highly prized species. The 

 resurvey also shows less larch and ponderosa pine. The decreases 

 were more than offset by increases in marginal species, chiefly 

 Douglas-fir, balsam firs, spruce and lodgepole pine. 



The volume per acre of saw-timber stands according to the 1948 survey 

 averages 9.1 thousand board feet in contrast with 7.7 thousand by the 

 1935 survey. However, variations in survey methods may account for 

 this difference. For, as classified by the 1935 survey in units of 

 40 acres or more, saw-timber stands included areas of other stand con- 

 ditions of relatively low volume. Most of these extraneous elements 

 were factored out in the 1948 survey by the use of 0.4-acre sampling 

 units. If, for example, the woodland area (98 thousand acres with 168 

 million feet of volume) is included with saw-timber stands as in 1935, 

 the average per-acre volume of saw-timber areas is lowered to 8.6 

 thousand board feet. 



Average pole stand volumes decreased from 3.3 to 2.0 thousand board 

 feet per acre. The higher volume pole stands of 1935 were reclassi- 

 fied as saw timber in 1948 which tended to lower the average. This 

 trend was accentuated by a shift of seedling-sapling areas to pole 

 stands of relatively low volume . 



Average volume of seedling- sapling stands remained approximately the 

 same — 379 and 396 board feet per acre, respectively by the 1948 

 and 1935 surveys. No volumes were estimated for deforested areas in 

 the 1935 survey. According to the 1948 survey poorly stocked and de- 

 forested areas average 1066 board feet per acre. Excluding the wood- 

 land area the average is 749 board feet per acre. The woodland area 

 of 68 thousand acres, averaging 1714 board feet per acre, is classified 

 as poorly stocked and deforested because the volume is less than the 

 minimum of 2000 board feet per acre set up for saw-timber stands and 

 for lack of sufficient pole and seedling- sapling trees to qualify for 

 either of these stand categories. 



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