. Slash fire atmospheric pollution. Air Pollution; Slashburning Environmental aspects Northwest, Pacific. Rate of energy release (calories per second). 0 1 2 Time (hour) Figure 7. — Estimated rate of energy release for the broadcast fire on Pack Forest, June 25,1968. An adjoining unit was broadcast burned with conventional drip torches and diesel fuel. An attempt was made to obtain the same rapid rate of heat generation as on the hectare unit. The cost of burning the smaller unit was $133 per hectare ($54 per acre). However, because the risk of wildfire was high, a 30
. Slash fire atmospheric pollution. Air Pollution; Slashburning Environmental aspects Northwest, Pacific. Rate of energy release (calories per second). 0 1 2 Time (hour) Figure 7. — Estimated rate of energy release for the broadcast fire on Pack Forest, June 25,1968. An adjoining unit was broadcast burned with conventional drip torches and diesel fuel. An attempt was made to obtain the same rapid rate of heat generation as on the hectare unit. The cost of burning the smaller unit was $133 per hectare ($54 per acre). However, because the risk of wildfire was high, a 30-man standby fire control crew was used. FUEL BURNED The pre- and postfire inventories () were used to compute the total amount of fuel burned. The results are shown in table 6. The weight change for duff may be greater than shown. In postburn samples, no distinction was made in most cases between burned duff, unburned duff, and ashes. The weight of material greater than 10 centimeters in diameter increased after burning. This may have been due to the low sampling intensity or the bias introduced either by burial of this material by fine fuels before the fire or exposure of the material afterwards. However, only an outer shell of approximately 1 centimeter was charred on material 10 centimeters in diam- eter or larger. Because the amounts of material in this size class were approximately the same in both surveys, an estimate of the material which actually burned was made by computation of the volume per plot of this 1-centimeter shell and use of this figure in table 6. Mineral soil exposed prior to the burn was estimated to be 10 percent; after the burn, 18 percent. This difference may not be statistically significant since only half of the plots were remeasured after the burn. The average duff depth before and after the fire changed from to centimeters. Some of the material repre- sented as duff in the postfire remeasurement consisted only of ashes and
Size: 2445px × 1022px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
