Forest Fires: Fire Management and the Power Law

Forest fires do not only destroy plants, animals, and structures, but also change the ecology of the habitat. While research of fire dynamics is a hot topic, there are many controversial issues in the field. Forest fires are commonly considered best examples for a scale-free, power-law distribution. We developed a model of a simple ecosystem that questions this and other well-established understandings. We show that in fact forest fires are not scale-free, power-law phenomena, but are generated by different processes. Our model also shows that trees and tree-dependent animals are affected by the fires differently. In prescribed fires, the forest will burn locally with smaller fires and this will not allow for a high accumulation of fuel in the forest. While trees tend to survive or re-grow, forest animals will easily go extinct. Without prescribed fires, more fuel will accumulate, which leads to an occasional single massive fire, where a large percentage of the forest will be destroyed, but the animal population is able to rebound and spread back from unburned patches. Our model provides a clear prediction that forest animals could be endangered by prescribed fire managements.