New Model Estimates Historic Fire Frequency
Knowledge of historic fire frequency is important in guiding restoration of fire-dependent ecosystems, but it is often missing or cannot be determined locally because fire scar tree records are lacking. A Forest Service scientist and collaborators have developed a new model called PC2FM (physical fire frequency model) that predicts historic fire frequency for the continental United States.
The model is based on the fundamental laws of physical chemistry that govern combustion and hence forest fires. The model was calibrated and validated with North American fire data from 170 sites that date before 1850 and the widespread industrial influences related to land use, fire suppression, and recent climate change that affect the occurrence of wildland fires. The model uses mean maximum temperature, precipitation, the interaction of temperature and precipitation, and estimated reactant concentrations to estimate mean fire intervals (MFI).
Having science-based estimates of historic fire frequencies for specific project areas is a major advancement in ecosystem restoration. Another important use of the model is in assessing potential changes in climate (temperature and moisture) on the likelihood of wildland fires. The PC2FM model can be used to map large-scale historic fire frequency and assess climate effect on landscape-scale fire regimes.
Forest Service Partners