has not, of course, sustained an annual loss of 9 

 percent. Some of the rotten-cull trees may have 

 been fire damaged as much as 25 years ago, devel- 

 oping into their present rotten-cull state since that 

 time. On the other hand, the annual loss is much 

 more than one twenty-fifth of 9 percent, because 

 many trees that have been fire-damaged during the 

 past 25 years have rotted, died, and disappeared 

 from the stand, and also because much of this loss 

 has taken place over a considerably shorter period 

 than 25 years. While the percentage of fire-cull 

 volume cannot be determined exactly, it is con- 

 siderable; and it can to a large extent be prevented. 

 In 1934, no forest areas in the survey unit were 

 under organized fire protection. 



Damage Due to Other Causes 



In addition to rot directly traceable to fire, there 

 is a considerable amount of rot due to causes other 



than fire. Still other timber losses are directly at- 

 tributable to wind throw and wind breakage, log- 

 ging damage, lightning, and other causes. Fire and 

 rot, however, destroy incomparably more volume 

 than all other agents combined. Hardwood trees 

 are seldom, if ever, killed outright by insect attacks, 

 and very little loss of timber volume is directly 

 traceable to insect activity, although ambrosia 

 beetles and other boring insects, some of which gain 

 access to the tree through fire wounds, cause con- 

 siderable loss in value through degrade of lumber 

 and other commercial forest products. Also, con- 

 centrated woodland grazing near farming areas 

 tends to reduce the quality and quantity of repro- 

 duction and may, in extreme cases, even eliminate 

 it. Much of the forest land in the clear-cut con- 

 dition is the result of elimination of reproduction 

 by grazing, coupled with continuous cutting for 

 local use. 



52142° — .38 4 



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