The cover types in Alaska do not correspond to 

 those in continental United States,- therefore, no 

 valid comparison of area burned can be made 

 without modifying some terminology. In conti- 

 nental United States rate of spread is greatest in 

 grass fuels. A large share of the lands protected 

 by the Bureau of Land Management in continen- 

 tal United States is covered with grass; the next 

 largest acreage is brushland. In Interior Alaska, 

 grassland comprises a small percent of the total 

 acreage,- much of that is on the Kenai peninsula 

 where lightning incidence is very low, accessibil- 

 ity is relatively good, and fire danger seldom be- 

 comes critical. 



Tundra and related fuels are not included 

 on fire reports,- fires in tundra are arbitrarily 

 classed in the "Other" fuel type category. Rate 

 of spread in this complex is as great as, if not 

 greater than, rate of spread in the grass type. 

 The information in figure 51 would be more re- 

 alistic if most of the BLAA Alaska acreage that is 

 now listed in "Other" fuels were placed in the 

 "Grass" category. 



Seventy-four percent of the acreage burned 

 in Interior Alaska is in forest or tundralike fuels. 

 Eighty-eight percent of the acreage burned on 

 other BLAA protected lands is in brush and grass 

 fuels. Forty percent of the acreage burned in 

 Interior Alaska is in forest fuels, compared with 

 only 7 percent on other BLAA protected land. A 

 relatively greater strength-of-attack force is 

 needed for controlling fires in forested land. 



INTERIOR ALASKA, WITH SOUTHEASTERN 

 ALASKA 



Up to this point all of the statistics have 

 referred only to Interior Alaska. The differences 

 in weather factors and fire loads between the 

 two sections of the State make this understand- 

 able. The brief tabulation below compares the 

 precipitation patterns of Interior Alaska with 

 those of southeastern Alaska,- it reveals two 

 entirely different climatic situations. Interior 

 Alaska has been termed "the green desert," but 

 southeastern Alaska approaches a rain forest 

 condition. 



Interior Normal annual Southeastern Normal annual 

 stations precipitation stations precipitation 



Inches Inches 



Fort Yukon 6.54 Seward 68.08 



Fairbanks 11.92 Juneau 90.25 



Anchorage 14.27 Sitka 96.33 



Bethel 18.17 Ketchikan 151.93 



Past fire records place nearly all the Alaska 

 fire incidence and burned area within the Interior 

 (table 14). 



Abundance of precipitation in the southeast 

 accounts for the heavy stands of Sitka spruce 

 and western hemlock timber. AAuch of it is 

 overmature: this indicates relative freedom from 

 fire. But many stands in southeastern Alaska do 

 show evidence of fire in their age and species 

 composition. 



Fire potential in the southeast increases as 

 timber is cut. Large volumes of logging slash 

 accumulate and expose the ground surface to 

 insolation and rapid drying,- this encourages 

 growth of flammable grass and annual weeds. 

 The number of people in and near the woods 

 also increases as utilization increases. 



The most urgent task is to reduce the 

 annual burned area in Interior Alaska from 

 the present 1,119,130 acres. However, the fire 

 potential in the southeastern section must be 

 realized; collection of certain elements of back- 

 ground information there will be of value to any 

 fire research program that may ultimately be 

 established. 



WITHIN INTERIOR ALASKA 



Lightning and Man-Caused Fires 



Only 24 percent of all forest fires in Alaska 

 are lightning caused, while 76 percent of the 

 acreage burned is due to lightning fires (fig. 52). 

 Inadequate storm detection and difficult acces- 

 sibility contribute to the high area-to-incidence 

 ratio. Probably the greatest fire control chal- 

 lenge is to reduce the acreage of lightning fires 

 to approach the incidence percentage. Early de- 

 tection and fast attack facilities will help bring 

 the acreage burned into line with the number of 

 fires. 



Fires on Which No Suppression Action Was Taken 



Several interesting but often confusing sta- 

 tistics result from comparing the group of fires 

 on which suppression action was taken with the 

 group that burned completely unrestricted. Al- 

 ready mentioned is the fact that control action 

 cannot be taken on some fires because: (1) they 

 are physically inaccessible; (2) they are so large 

 when discovered that no reasonable force of 

 men could stop them (economically inaccessible); 

 (3) limited manpower makes it imperative to 



59 



