38 



A. ^^mage to Merchantable Timber 



Studies made by the Forest Service on represen- 

 tative areas which have bieen Light Burned show that 

 considerable damage to the merchantable stand almost 

 always results. Records kept by the Forest Service 

 between 1908-1918, prove that fires have caused an 

 average annual loss of almost 39 faillion board feet 

 on both federal and private lands within the National 

 Forests in California. 



(1) $)amaffe Resulting from Burning Down o f Pre- 

 viously F i re-scarred Trees 



A considerable portion ofthis loss occurs through 

 the burning down of fire-scarred trees. Fire-scarred 

 trees occur throughtaut the Sierra region and comprise 

 a large percentage of the merchantable stand. On some 

 areas these trees may form 75^ of the merchantable stand, 

 although the average for the entire region is much leas 

 than this (perhaps 20^). The species most commonly 

 deeply scarred are yellow pine, sugar pine, incense 

 cedar and douglas fir, in the order named. Scars caused 

 by fires are always on the up-hill side if on a slope. 

 This is no doubt due to the accumulation of inflammable 

 debris against the side of the tree, which when ignited 

 forms a fire of sufficient intensity to scar the tree. 

 In Light Burning an are upon which are fire-scarred 

 trees, it has been found impossible to prevent consid- 



