ROLE OF FIRE IN CALIFORNIA PINE FORESTS 41 
are the season when the fire occurs and the direction of wind, the 
latter largely determining whether fire burns up or down hill. 
One major result of past fires has been the stripping of the mer- 
chantable timber from nearly 1 acre out of every 7 of timber-produc- 
ing land. At a very conservative estimate, this represents a loss 
36,000,000,000 board feet of timber or, at the present rate of cutting in 
the pine region, enough to run all of the aul in the region for nearly 
half a century. 
In a comprehensive survey of the pine region of California, perhaps 
the most striking feature is the vast area of land within the timber 
belt proper that brush occupies. Disregarding entirely the chaparral, 
still no careful observer can fail to be impressed with the unproduc- 
tiveness of what was once timber-producing land. 
Out of a total area of 13,625,000 acres in 10 of the important 
national forests in the central and northern parts of California, there 
are estimated to be 1,862,000 acres of brush fields. This total area, 
comprising the Sierra Nevada, the Coast ranges north of Clear Lake, 
and the eross ranges of northern California, embraces by far the 
iargest part of the California pine region. Table 19 shows both the 
total extent and the relative importance of the brush fields in the 
different parts of this region. 
TABLE 19.—Brush-field areas in 10 of the national foresis of California 
National forest Total area ! | Area of brush fields 
. 
Acres Acres Per cent 
Gr RErcUhie ere ene ee ee ee ee og ee 1, 734, 665 254, 550 14.7 
JST Ee eee eR Pe Rese i py ee os eas ees Ged ee Penge eeeee ee Came AU ae ed 1, 724, 125 246, 200 14.3 
SHG 2 ee ev See Sb SS ee SS Se Se ee ger 1, 630, 000 318, 000 19. 5 
CHBTORRIAES 2208 22ers a CaP R EEE Peay los ee Pile eae fi be 1, 062, 572 201, 0060 18. 9 
ese ns rage Ree SP ie SE i Sa Ses aes eee On Ges ee 1, 306, 287 154, 490 11.8 
AVIS ES Ss Sei lle te ey gece gd J pt el a a ea agen 1, 458, 140 170, 000 1e7 
Verling base Sees Se! SS ae tet oe Se ho) ee een eee eee ho eee 1, 106, 137 95, 000 8.6 
ISLeSrerg he Dene SN a aps a eg ee ee en eee ee | $35, 800 58, 200 7.0 
Sirens lemisey eee SP ape oti oee Yip ict ite Se bie io 1, 104, 412 179, 230 16. 2 
STA er. Ao ae Re Se Se Ee ee Se ee | 1, 662, 560 185, 000 ll 
DONTE cee Ses oes ee See es oe Sener et 13, 624, 698 | 1, 861, 670 13.7 
1 Includes Government and private land within nationa! forest boundaries. 
RECLAIMING THE BRUSH FIELDS 
The history of such recent burns as the Howard fire proves that 
timber stands may be destroyed by repeated fires and that brush 
then occupies the ground. But just as the fire scars in the timber 
stands show that the forests have been subjected to repeated fires, so 
do the older brush fields themselves furnish convincing evidence that 
they are the result of fires. Although brush fields are spoken of as 
‘;onproducing areas, it should not be inferred that forest trees have 
been completely eliminated from the areas now occupied by brush. 
The most convincing proof that the brush fields are the result of fire 
is that within a comparatively short distance there may be found all 
the gradations from a stand of merchantable virgin timber to a stand 
of brush with no living trees. (Pl. VIII.) Other evidence that the 
brush fields were formerly timberland, and have reverted to their 
roe condition chiefly through fires, may be summarized as 
ollows: 
