16 BULLETIN 1200, U. S. DEPARTMENT OF AGRICULTURE. 
The temperatures were recorded with a Leeds and Northrup 
potentiometer, which insured accurate records. The germination of 
seed that passed through the fire is given in Table 6. 
TABLE 6.—Germination from Douglas-fir seed stored in slash during fire. 
| | 
| 
gens Number | | Extreme 
ae | ofseeds (Percentage | tempera- 
os Goss germinated germinated.) tures 
| Pie }in nursery. | | during fire. 
; | ite 
Station 1. Under 1 inch of mineral soil in skid road...... 9,104 | 2, 082 | 22.9 | 75 
Station 2. 14 inches under surface of rotten log.......... 6, 751 | 1, 354 | 20.1 | 65 
Station 3. In mineral soil under 1}inches of duff; direct- | | 
Ty 1nder ‘Statioit fost ee eer rn ee ee 9,118 | 1, 621 | 17.8 | 60 
Station 4. Under 3 inch of duff; directly over station 3... 5, 235 | 1,281 | 24.5 120 
Check. “Not-heated 2635 oo ee re eae pare eee ge 7, 552 2, 033 26; Sue es cee 
Station 5. 30 inches above ground. Directly over sta- | | | 
tions.) and 4.2... decel scare Seebeck coerce ARS. 8 hice anmarerd oes | arcing | 850 
3 | 
The relatively low percentage of germination may be attributed 
to the poor quality of the seed used, as the check tests also show a 
very low germination. 3 
The temperatures recorded in Table 6 explain some of the condi- 
tions found after slash, fires in this region. Strips of young growth 
commonly spring up along skid roads on certain areas, although 
there may be very little reproduction on the remainder of the area. 
The records show that any seeds buried by skidding would be pro- 
tected through the slash fire and would germinate along the skid 
reads. The same principle holds for areas lightly burned or burned 
when the duff is moist. When the forest floor is dry practically the 
only seed protected is that buried deep in the mineral soil. 
The moisture content of the soil and duff is a most important fac- 
tor in protecting the seeds during the fire, as the moisture prevents 
the duff from burning and reduces the temperature of the duff or 
soil. The moisture readings taken before and after the fire are given 
in Table 7. 
TABLE 7.—Moisture content of soil or duff where seed was stored. 
Percentage of mois- 
< ture content. 
| Before fire. “After fire. 
| 
Station 1. Under 1 inch of mineral soil in skid road..................- 2 ee eae |: 28. 81 11. 87 
Station 2. 14 inches under surface of rotten log. .-..........--...---.-222-------- 81.71 72.78 
Station 3. In mineral soil under 14 inches of duff; directly under station 4........) 9.19 12. 79 
Station 4. Under 3 inch of duff; directly over station 3-.....................---- 58. 06 51.76 
The fire apparently had some drying effect, as the moisture con- 
tent at each station, except station 8, was less after the fire. The 
drying at any of the stations was not pronounced enough.to- be in- 
jurious to the seed. : 
