ROLE OF FIRE IN CALIFORNIA PINE FORESTS 58 
Examination of September, 1913, less than three years after fire 
Litter still increased by falling leaves; brush sprouts increasing; hazard greater 
than before fire, part of needles still on trees, bark and twigs still falling. 
More recently an opportunity on a larger scale has been afforded 
for a conclusive study of the costs and results of light burning as a 
means of reducing hazard in California pine region. 
From early July until the latter part of August, 1920, a fire 
burned in the Moffitt Creek watershed in Siskiyou County, covering 
an area of about 11 square miles and causing a heavy loss in mer- 
chantable timber both by heat killing and by burning down, averaging 
3,390 board feet per acre. The land was privately owned, largely by 
the Central Pacific Railway Co. The California Forestry Committee, 
on the request of the principal owner, decided to conduct experiments 
in light burning here, primarily with the idea of keeping the hazard 
a a low point and to determine the costs of large-scale operations 
(4, ). 
The first attempt to carry out this project was made in the spring 
of 1921. After more than a month’s efforts only a very small part 
had been burned. Most of the time rains prevented burning at all, 
and a few days after the last rain the forest floor became so dry that 
it was considered dangerous to set fires. In the fall of 1921 slight 
progress was made in reburning the area. Weather conditions con- 
tinued uniformly dangerous up to the time of the first fall rains, after 
which fire would not spread. 
Similar climatic difficulties were again encountered in the spring of 
1922 when a crew of men tried for 13 days to fire the area and were able 
to burn only 32 acres. Frequent rains made it impossible to obtam 
burns even on southerly slopes during the first 10 days, after which 
the weather suddenly became dry and hot. On the thirteenth day 
fires spread so papidiy that the work had to be abandoned. 
One area of 12 acres, burned in June, 1922; just before the abandon- 
ment of the work, the fire being generally ight and spreading down- 
hill, was examined in detail in October, 1922. It was found that 6 
western yellow pines and 4 Douglas firs, totaling 5,470 board feet, had 
been burned down, while 4 western yellow pines and 3 Douglas firs, 
totaling 3,710 board feet, had succumbed to ben killing. The average 
direct loss from both these causes equaled 765 board feet per acre. 
Even this small area shows in an epitomized form the results observed 
on other light burns, that unless trees are individually protected 
material loss to merchantable timber may be anticipated. 
The effect of the light-burning operation on reproduction as shown 
by a detailed survey on 2.6 acres, was such that of the original stand 
of 280 seedlings and saplings per acre only 5.7 per cent survived. 
The area was thus left practically denuded of advance reproduction. 
REPEATED LIGHT BURNS—NEVADA AND PLUMAS COUNTIES 
It is important to determine whether repeated surface fires actually 
reduce the inflammable material to the point where forests are immu- 
nized against serious damage from subsequent fires. 
e only areas on which there are definite facts as to the cumulative 
effect of several controlled fires, either on the forest itself or in reduc- 
ing hazard, are the second-growth stands of western yellow pine on 
