Ss Sete 
NATURAL REGENERATION OF DOUGLAS FIR. OT 
bark and had been able to force their way to the edge of the bark 
before the food stored in the seed was exhausted. 
Some spring burns have been found where but little young growth 
followed the slash fire, and good stands have been found on areas 
burned in summer or fall; but the importance of spring burning 
is emphasized by the superiority of the average stands of young 
growth on these burns as compared with the young growth on the 
later burns. The average conditions of restocking are shown in 
Table 16. Fall burning may sometimes be done almost as safely 
as spring burning, but usually it is too wet to burn the slash after 
the forest floor has become wet enough in the fall to protect the seed. 
TABLE 16.—Average number of Douglas-fir seedlings per acre on areas burned 
over by slash fires, examined 2 to 5 years after fires. 
Chains? distant from seed trees. 
1 2 3 4 5 6 7 8 9 10, 
Slash burned in spring first | 
season after logging.......... 690 485 | 1,125 | 4,120 570 160 218 565 | 2,714 | 12,905 
Slash burned in summer first 
season after logging.......... 310 165 415 65 50 0 | 0 45 15 0 
Areas reburned after first | 
Slash finde) coe ees s heel 665 | 345 | 510.) 1654) 0410 0 0 0 | 0 65 
Chains? distant from seed trees. 
11 12 13 14 15 16 Lar Fo ae) 20 20 
Siash burned in spring first sea- 
son aiter logging.../........-. 5,220 | 4,130 | 9,190 | 670 | 2,115 | 4,568 1,675 | 6,460 | 5,120 | 1,365 
Slash burned in summer first 
season aiter logging........... | 0 0 6 | 16 65 140 85 15 209 0 
Areas reburned after first slash 
PUTO are aaa oe ey Wane so Paoy 0 0 110 35 0 | 0 0 | 0 | 0 | t} 
1 Based on 7.5 acres examined by plot and transect method. Early fall burns usually occur before the 
duff and soil are wet; consequently the effect isthe same as that ofsummer burns. Both types are included 
in this summary. 
21 chain equals 66 feet; 20 chains equals one-fourth mile. 
On areas burned more than once it is possible that a few dormant 
seeds still remain. The endurance of such seeds may account for 
some fairly good stands at considerable distances from seed trees. 
Likewise, the distribution of seed by wind and birds, combined with 
favorable conditions for germination, may result in a scattered stand 
in some localities, but other areas with less favorable conditions re- 
maim banren, “Cel YX, fig: 2.) 
RESTOCKING BY SEED TREES. 
On one area studied no seed trees of any species were left, except 
scattered Douglas-fir trees. The nearest stand of timber was about 
one-fourth mile distant. On this area, four years after the fire, an 
average of 3,680 seedlings per acre was found. Of these seedlings, 
1 per cent was Douglas fir, 16 per cent grand fir, and 83 per cent 
western hemlock. The occurrence of the grand fir and hemlock seed- 
lings can not be attributed to seed trees, and even the origin of the 
1 per cent of Douglas fir seedlings is doubtful. Although the 
Douglas fir trees left on the area were known to have produced crops 
of seed, the entire crop was evidently destroyed by rodents. This 
