30 BULLETIN 1495, U. S. DEPARTMENT OF AGRICULTURE | 
in another way, it means that if 1-hour control is correct for the fir 
type, 1-minute control would be required in the chaparral to maintain 
the same average size of fire. The rate in chaparral is nearly seven 
times as high as in western yellow pine, the most hazardous of the 
timber types. The Douglas fir type has almost exactly the same 
rate of spread as the western yellow pine. 
' The ratio between the index figures for the western yellow pine 
and fir type is about 744to1. In the existing protection organization 
the difference between the two types is recognized only to the extent 
that on the average in the fir type one protection man covers three or 
four times as much territory as in the pine type. The average for 
the low-value chaparral, grass, and woodland types is six times as 
great as for all timber types. Any theory of basing protection effort 
on timber values at stake would place the emphasis on the timber 
types. But the situation requires even greater effort in the low-value 
types, for the sake of the watershed values at stake within these 
types and to insure against spread of fires into adjacent timber stands, 
as well as to reduce the number of large fires requiring high expendi- 
tures for suppression. 
In the fir type an average elapsed time of 27.14 hours has held the 
acreage burned by general-risk fires to 0.18 per cent of the type area 
annually. In the western yellow pine an average of 15.64 hours has 
resulted in an annual loss of 0.87 per cent. 
The figures do not lead to the conclusion that the intensity of pro- 
tection should be decreased in the fir type, but rather that it should 
be increased elsewhere. ‘The success attained in the fir type indicates 
that existing protection is about right to hold the annual burned 
acreage to the proposed maximum of 0.2 per cent annually. The 
index figure for the brush type is 69 per cent higher than that for 
the western yellow pine, indicating a need here for intensive protection 
even more urgent than in the commercial-timber types. 
TABLE 16.—Cost of class A fires by types, 1911-1920, all causes, 12 timbered 
forests 
Class A Total | Cost per 
Type fires cost A fire 
Number | Dollars | Dollars 
Wiestern.yellowspin@s:) =o 2a acess ie ee ee ee ee 1, 627 8, 185 5. 03 
Mixed: conifer 222 = 22-22 3 a2 DR eee ee 5 ee ee a ee ae ee ee 1, 263 6, 404 5. 07 
Douglas j U1 ae See ee Sp Oran, ee Emre aR eae Sk Set To Das 251 1, 481 5. 90 
Buea [OE A Ses #6 age teen Cesta Nat OS ans ee LOI oui es od So 109 501 4. 60 
By ep ee ee ap pie the neh en oe ga Sc ere air pene Pe Shien ga eh irad Ghee ek a tps 474 1, 966 4.15 
Gas Sg REE SR cB MGS oe Peg SONS PN NSAN SES ADC INES Sa MOY Pele pO P ERTS. gn DSN AN 27. 3.61 
Chaparral: 2252 so 3S eS SEA ae Sa I eg SS een ee 56 582 10. 39 
Wieodland ete oa ae ae ee ee nee Rimes 107 302 2. 82 
Bushs aes $e. BR Sis a a ha ye Bia yt he a et 388 2, 926 7. 54 
CASVOPAG Cs tag SEE 2k ee 2 2 Ne Ree ae | ap eee | a 5. 20 
SUMMARY BY TYPE GROUPS 
Western:yellow: pine; mixed conifer zroup-- => =) 2 eee 2, 890 14, 589 5. 05 
Sugar pine-fir-tir. DW Ouglas fil SrOU pa. oe eee ee ee ee a ee 34 3, 4.73 
AW timber 042s es Pr ee ee ee eS ee 3, 724 18, 537 4. 98 
Brush; chaparral: croup... ee be ee es oak ee ee 444 3, 508 7.90 
Grass, woodland group: <7 aa ee ee eee | 184 580 3.15 
