30 BULLETIN 1200, U. S. DEPARTMENT OF AGRICULTURE. 
areas too distant from green timber for restocking by wind-blown 
seed it is extremely important to protect the young trees in order 
that they may serve as seed trees for the area when they reach seed- 
- ing age. (PI. VI, fig. 1.) : 
DISTRIBUTION OF YOUNG GROWTH AFTER TWO OR MORE FIRES 
ON THE SAME AREA. 
Repeated fires on large burns are a more serious menace to a 
forest cover than the first fire, because if a reburn occurs before the 
new stand has reached seeding age it may produce an area which 
will remain barren for an indefinite period. (Pl. VI, fig. 2.) 
A number of fires had occurred in the Cispus region. on the 
Rainier National Forest, and consequently it afforded suitable areas 
for the study of the effects of repeated burnings. Evidence was 
found of a general fire over the entire region in 1660, and of local 
fires in 1761, 1874, 1892, 1902, and 1910. During the studies of 1914 
the types of forest following these burns were analyzed. On the 
areas where the forest had reached maturity or had grown to middle 
age (100 years or more) the same conditions prevailed that were 
found after one forest fire; that is, a good stand of reproduction fol- 
lowed the first fire, and although the reproduction varied in density, 
the area could be classed as restocking. In the localities where a 
second or third fire occurred before the stand reached seeding age, 
only limited areas were restocking by seeding from the remaining 
seed trees or stands of timber. This was definitely checked by a 
series of permanent plots on areas that were burned in 1902, 1915, 
and 1918. A good stand of young growth followed the 1902 fire 
where the mature forest had been completely killed. When this 
young growth was 13 years old, and before it had reached an effec- 
tive seeding age, it was destroyed by the fire of 1915. The mature 
Douglas fir trees in the vicinity that had escaped the 1902 fire were 
not injured by the 1915 fire. This same area was burned by the 
general fire of 1918, and again the mature trees escaped being killed. 
Young growth appeared near the seed trees after each fire, but only 
for distances of 6 chains or less, and very little at more than 4 
chains from the seed trees. 
Another area near the source of the Cispus River demonstrated the 
effect of repeated burning. A burn in 1764 was followed by a sparse 
stand which was reburned in 1870 at the age of 106 years. The 
burn of 1870 was again restocked with a scattered stand, which in 
turn was destroyed by the fire of 1910, when the stand was 40 years 
old. The 1910 burn still remains a denuded area. The explanation 
of this process of denudation lies in the successive fires that occurred 
before sufficient duff had accumulated to protect seed stored in the 
forest floor, and in the porosity of the soil which provided such good 
drainage that the humus and duff were dried out. Under these con- 
ditions the forest floor is usually burned severely; probably all of 
the litter and duff are consumed, and the soil is heated deeply enough 
to destroy most of the seed. This process has been noted in other 
forest types. It occurred again in the same locality during the 1918 
fire, which swept over the Cispus and Spring Creek drainages. _ 
The large area burned by the Cispus fire of 1902 was to a great ex- 
tent covered by young growth, except locally, where subsequent fires 
burned in 1910 and 1915. On June 27, 1918, a second big fire, which 
