26 BULLETIN 1294, U. S. DEPARTMENT OF AGRICULTURE 
heat killing of merchantable timber; while over the greater portion 
of the burn the damage took the form of reduction of the stand. 
Since the young growth was smaller and more susceptible to fire 
than the merchantable timber, the percentage of such reduction was 
naturally greater. 
A study was made of a large area in the east side western yellow 
pine type burned over in the summer of 1920. Cruise lines were run © 
through the burn and each one-tenth acre square on each side of the 
line was classified as to the degree of stocking of the reproduction 
before the fire, the percentage of the ground burned over, and the 
percentage of the reproduction killed. The survey covered a total of 
379 sample plots, almost 38 acres, along a mechanically located 
strip, fairly sampling a burned area of approximately 2,000 acres. 
This study showed that, in general, the heavier the original stock- 
ing on the plots the higher was the percentage of the area burned; 
that is, very open and scattered stands of reproduction had a better 
chance of escaping the fire than did the denser stands. The propor- 
tion of reproduction killed followed closely the proportion, of the area 
burned. Considering only the grand average of all the data, 69 per 
cent of the plot area was burned, and 64 per cent of the reproduction 
was killed. 
It is shown that instead of uniformly thinning the stands of seed- 
lings and saplings, a surface fire wipes out a certain portion of the 
stand wherever it runs. Outside the: area actually burned, and yet 
within the boundary of the burn as a whole, there will be a certain 
amount of reproduction, even though small, that is able to survive. 
This is exceedingly important, for it means that fire creates a patchy, 
scattered distribution of reproduction, with many areas denuded but 
others left intact. On the more intense burns, such as the Howard 
and Soda Creek fires and on the more heavily burned parts of the 
other areas, not even occasional patches of unburned reproduction 
are left, but complete destruction of reproduction is the rule. 
RARE INSTANCES OF BENEFICIAL EFFECTS 
Fires in the early spring, or late fall after the first rains, are nat- 
urally less destructive than in the summer, because of the more moist 
condition of the litter. Studies on the Castle Rock, Red River, Snake 
Lake, and Sierra Iron Co’s burns show that with very light fires the 
stands of large reproduction, especially in the sapling and pole stages, 
may sometimes be thinned by fire without complete destruction of the 
entire stand. As an example of the way in which a fire acts under 
such circumstances, an area of slightly more than one-third of an acre, 
with reproduction ranging from seedlings to poles 12 inches in diame- 
ter, was studied. As shown in Table 12, only a very low percentage 
of seedlings escaped death; but the larger the trees the larger the 
percentage that lived. Though only 20 per cent of all the young trees 
survived, they represented a total of 480 trees to the acre consisting 
chiefly of the larger individuals, and were quite sufficient to give a 
reasonable degree of stocking. As the surviving trees were uniformly 
distributed, there is no concern in this particular case over the heavy 
loss of seedlings and saplings. 
