36 BULLETIN 1200, U. S. DEPARTMENT OF AGRICULTURE. 
TABLE 15.—Average number of seedlings per acre in unburned slash 2 to 15 
years after cutting—Continued. 
Chains distant from seed trees. 
Species. | 
il 12 13 | 14 15 16 17 18 19 20 
|__| | | 
Douslasnn. Mh sese: 172 65 155 78 150 35 48, 115 210 800 
Western red cedar..... O| 24 36 140 | 4,500 | 6,520] 3,610; 418] 1,670] 4,860 
Western hemlock. ....| 1,410 | 1,280 | 3,120 | 12,980 | 24,320 | 1,460 | 3,120) 4,200) 6,120) 8,650 
Poataler cet cece! 1,582 | 1,369 | 3,311 | 13,198 | 28,970 | 8,015 | 6,778 | 4,733 | 8,000 | 14,310: 
DISTRIBUTION AND SPECIES OF YOUNG GROWTH FOLLOWING SLASH FIRES. 
The large amount of débris left after logging in the Pacific North- 
west makes a very dangerous fire risk and necessitates burning the 
slash in order to protect the surrounding forests and property. This 
fire risk should be removed at the earliest opportunity. It is also | 
necessary for good forest management that the slash be burned the 
first season after cutting. The great amount of slash left after 
cutting a mature Douglas fir forest makes broadcast burning the 
only practicable measure of disposal. When a broadcast slash fire 
runs over an area it may affect the succeeding young growth in 
different ways. It may burn the surface layer of litter and duff and 
leave conditions favorable for a good stand of young growth with 
Douglas fir predominating; or, all the dutf may be consumed and a 
scattered stand of young growth result, except in very loose soil 
containing a good supply of seed; or, if the fire is hot enough to heat 
the mineral soil below the duff, a barren area may result. 
The heating of the soil is the important point, and this can be con- 
trolled by selecting the time for slash burning. In the spring the 
soil and duff are wet and little heating occurs. The young growth 
following spring burning is evidence of the desirability of burning 
the slash in the spring. 
An area in the Puget Sound region, which was logged in the fall 
of 1914, and on which there was a very severe slash fire in July, 
1915, afforded an opportunity to study the effect of a late spring or 
summer slash fire. A series of plots, each a rod square, was estab- 
lished immediately after the fire, and anna examinations were 
made for five years. (Pl. VIII, fig. 1.) Very. few seedlings fol- 
lowed after the July slash fire, except in the vicimity of green 
timber. All the seed on this area was destroyed by one fire, a pos- 
sibility that must not be overlooked in determining the time of 
slash disposal. In the same region large areas of dense stands of 
young growth have followed slash fires that occurred in the early 
Sprmae or late fale CPL’ Vill, fe 2: "Pl EX, fie. 1) 
The season of burning and the condition of the forest floor at 
the time of burning often determine whether or not young growth 
will foliow a slash fire. On the area burned in July several small 
western red cedar and western hemlock trees were left standing, 
but they were all killed by the slash fire. The reproduction that 
followed consisted of a few scattered seedlings of western red cedar, 
western hemlock, and Douglas fir, eenerally in rotten wood or 
under logs. Some Douglas fir seeds had germinated under pieces of 
