ROLE OF FIRE IN CALIFORNIA PINE FORESTS 33 
The Cement Hill fire on the Tahoe National Forest on Novem- 
ber 26, 1919, covered an area of over 600 acres. In spite of the fact 
that the fire was far past the time when fires ordinarily burn at all, 
it developed into a crown fire on many southerly slopes and obliter- 
ated the stand on many patches of 2 to 4 acres. 
SampLE Pitot or Cement Hix Fire, 1919 
(Sec. 35, T. 17 N., R.8 E., M. D. M.) 
Area.—0.6 acre. 
Fire history—No fires since 1881, except a small blaze confined to two trees in 
area showing scars 3 years old. Following light rain on November 4 and soak- 
ing rain on November 7, 1919, fire burned on November 24 and 25, 1919. 
Original stand.—50O years old, western yellow pine; 228 pines per acre, 5 to 22 
inches diameter breast high, 50 to 60 feet; 180 pines per acre under 5 inches 
diameter breast high. : 
Slope.—Gentle, not over 5 per cent, in a shallow swale, northerly exposure. 
Cover prior to fire.-—Very little brush, few old manzanita bushes dead from shad- 
ing of trees; some bear clover. 
Litter —Probably 1 to 114 inches thick, as judged from adjacent unburned areas. 
Reproduction.—Absent. 
Results of 1919 fire—Every tree killed on area; litter consumed to soil; bear 
clover scorched off; dead brush not all consumed. 
An enumeration in detail of all destructive fires in second-growth 
stands would merely be a repetition and amplification of the examples 
already given. Stands of this character represent an extreme hazard. 
Destruction of the forest on wide areas is to be anticipated at any 
time of the year when fires will burn at all, if fire occurs when 
weather conditions favorable to spread of fire, particularly high winds, 
prevail. 
As in the Pacific Northwest, not all fires in second-growth stands 
develop into disastrous crown fires, many either bemg controlled 
while yet small or protected by climatic and topographic conditions. 
Another reason that more extensive fires have not occurred in mer- 
chantable second growth in California is that most of the existing 
stands are in the foothill regions and are broken up into small tracts 
by agricultural clearings. 
ANNIHILATION OF STANDS 
The hazard in second-growth stands has been compared to that in 
the Pacific Northwest, ‘but there is one vital difference of ereat 
importance. Serious as the loss of merchantable material is in the 
Douglas fir and western white pine crown fires, investigation has 
proved that destruction of the stand does not reduce the burned-over 
area to a nonproductive state. Reproduction of these valuable 
species ordinarily appears promptly after such a fire, either from 
ormant seed in the forest floor or from seed on the trees at the time 
of their death. Regeneration in these regions is also readily obtained 
because of the favorable amount and distribution of moisture, and 
because of the earlier seed-bearing age of the important conifers. _ 
In striking contrast, crown fires in second-growth pine stands in 
California inevitably reduce the areas to sterility and establish a 
permanent brush cover. This is explained by the fact that dormant 
seed is not an important factor in the regeneration of these stands. 
2027°—24——3 
