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A NATIONAL PLAN FOR AMERICAN FORESTRY 



market, and nearly impossible to dispose of when lumber prices are 

 low. Decay in the forest may thus result in over cutting in order to 

 meet the demand for high-grade stock; in too high cost of high-grade 

 stock; in the glutting of the market with low-grade stock; in financial 

 injury to both the producer and consumer interests. 



A summary of the loss from decay in saw timber in the United 

 States is given in table 1. The figures on decay percentage, although 

 based primarily on estimates made in 1923 by lumbermen and by 

 State and Federal foresters for eastern species, with the same basis 

 supplemented by actual measurements for certain western species, 

 have proved reasonably reliable, for most of the species on which it 

 has been possible to check the original estimates by measurements 

 obtained since that time. For example, the original estimates placed 

 the loss in Douglas fir at 15-20 percent and the lower figure was 

 adopted to be conservative. Later, exact measurements on a large 

 number of plots of felled timber of various ages placed the average 

 loss in board foot volume at 17 percent. For a number of other 

 species similar checks have been obtained, but based on fewer data. 

 The figures in the present table are lower than the 1923 estimates by 

 1 percent each for oak and southern pine, 2 percent for gum, white and 

 Norway pine, and lodgepole pine, 3 percent for cottonwood and 

 aspen, 8 percent for western hemlock, and 17 percent for redwood. 

 The percentage for cypress has been raised by 4, and for western 

 red cedar by 5. The general trend is toward less cull, because a 

 decreasing proportion of our merchantable timber is in old-growth 

 stands. 



TABLE 1. Estimated cull due to decay in the standing saw timber of the United 



States 



This table does not include the loss in cordwood stands nor in 

 timber too small to be merchantable in which decay has already 

 commenced. Hardwoods, largely concentrated in the East, have a 

 higher loss than softwoods, while in the softwoods the eastern species 

 are considerably less decayed than the western. This is because the 

 eastern softwoods are largely cut over, and the saw timber is much 

 younger on the average than that in the West. 



Young timber is relatively free from decay, but as the age of a 

 stand increases, loss from decay increases steadily. This loss is 

 offset somewhat by volume growth of the trees which is rapid in 



