The number of extra-period fires measures 

 two things — effectiveness of the fire control 

 organization, and severity of the fire season. An 

 extra-period fire is one not controlled by 10 A.M. 

 of the day following discovery. The BLAA fire re- 

 port data allowed only the following approxi- 

 mation to be attained: a fire not controlled with- 

 in 24 hours from initial attack. With this in 

 mind, the figures comparing Interior Alaska 

 (1950-58) with Region 1, USFS (1954-60) are re- 

 markably close. 



Ratio of extra-period fires to 

 Size of fire total number of fires 



Interior Region 1 



Alaska USFS 



Percent 



1 acres or less 4 6 



More than 10 acres 36 35 



However, if the Alaska data were based on 



the time between discovery and control, the per- 

 centage of extra-period fires, for the larger fires 

 at least, would certainly be much greater in 

 Alaska. 



Forward Behavior of Fires at Time of Attack 



The importance of early attack is illustrated 

 in table 17. Usually fires with large final size 

 are more violent in behavior at time of attack 

 than small ones. Outstanding extremes in the 

 spruce type are indicated by the fact that 70 per- 

 cent of Class A fires are smoldering when at- 

 tacked, but 47 percent of Class E fires are crown- 

 ing when attacked. If fires could be reached 

 while still small and before they start to run, the 

 total control effort would be considerably les- 

 sened, as would also the loss and damage. That 

 goal can never be completely reached, as some 

 fires may begin running and crowning almost 

 immediately after they start; however, this infor- 

 mation about behavior must be kept in mind as 

 an important factor in both fire control planning 

 and dispatching. 



Table 17. — Forward behavior of fires in spruce type at time of initial attack 

 by percent within each behavior class and by size classes 



(Av. 1950-58) 



Final 



size Behavior 



class Smoldering Creeping Running Spotting Crowning 



Percent 



A 



70 



31 



12 



25 



7 



B 



19 



39 



41 



25 



17 



C 



6 



18 



22 



19 



19 



D 



2 



5 



5 



12 



10 



E 



3 



7 



20 



19 



47 



FIRE AS A MANAGEMENT TOOL 



Use of fire in forest management is at times 

 a controversial issue, but many protection and 

 silvicultural objectives that could not be attained 

 economically by any other means are being 

 achieved through proper use of fire. Helmers 

 (1960, p. 467) states, primarily in reference to 

 southeastern Alaska, but possibly for many 

 parts of Interior Alaska: 



The possibility that fire can be 

 used for silvicultural purposes is pure 

 conjecture at this time. However, there 

 is a need for reduction in slash volumes 

 to reduce the physical impediment to 

 regeneration as well as to reduce the 

 fire danger in newly regenerated cut- 

 ting. The seedbeds in cutover areas can 

 be improved to advantage. These fac- 

 tors alone make controlled use of fire 

 a tool worth investigation. 



93 



