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- Info
A computer-simulated evaluation of three silvicultural practices for reducing hazardous fuel conditions and extreme fire behavior in pine flatwood forests
| Author: |
Brose, P. |
| Date: |
2000 |
| Periodical: |
Irvine, PA: USDA Forest Service, Northeastern Research Station. 27 p. |
| Abstract: |
Because of excellent growing conditions, pine flatwood forests in the coastal plain region of the southeastern United States can develop tremendous amounts of highly flammable undergrowth (rough) in only a few years, necessitating intervention to reduce hazardous fuels and prevent catastrophic wildfires. A computer modeling study was initiated in 1998 to determine the potential fire behavior in pine flatwood forests following partial timber harvest, prescribed fire, and understory herbicide application to reduce hazardous fuels. Three sites were selected, each representing one of the treatments, and at each site 15 stands covering a range of rough ages, time since the last silvicultural treatment, were chosen. The stands were inventoried for height, fuel load, and percent cover of the rough and these data were used to develop a custom fuel model for each treatment/rough age combination. These models were then used in the BEHAVE fire prediction system to estimate fire behavior and probability of overstory pine mortality under drought and normal weather conditions for each treatment/rough age combination. In all untreated stands (rough age > 10 years), BEHAVE predicted extreme fire behavior, making any fire control operation very difficult and probably ineffective, and 100% mortality of overstory pines. Prescribed burning provided immediate protection for the pines by reducing fire behavior under both weather conditions. However, this protection quickly disappeared as the rough aged and the shrubs recovered following the prescribed fire. Partial harvest impacted fire behavior in much the same manner and for a similar length of time as prescribed fire. Understory herbicides showed little immediate reduction in fire danger. However, beginning in second year after treatment, fire behavior decreased, a condition that lasted at least until year 6, making survival of overstory pines and successful fire suppression more likely. Under some circumstances, partial harvests and understory herbicides can substitute for fire to reduce fire behavior in pine flatwood forests but forest managers must be aware of each alternatives strengths and weaknesses. Combining treatments may provide immediate and long-term fire protection but these combinations need more research. |
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