Ignition probability of organic soils

Evaluating the effects of prescribed fire and wildland fire requires a greater understanding of the fire behavior of organic soils. Determining the ignition limit of organic soils over a wide geographical area is the subject of this study. Side ignitions were attempted with an electrically powered red-hot coil to simulate common ignition by lateral smoldering. Inorganic content was fixed by the sample's origin. Moisture content was altered to establish a moisture range that included the ignition limit. Recorded successes and failures of attempted ignitions were analyzed through logistic regression to give ignition probability based on the moisture and inorganic content and the organic bulk density. These probabilistic results lend themselves to lightning and person-caused fire occurrence predictive systems required for wildfire management. A limited comparison of results with Frandsen (1987. Can. J. For. Res. 17: 1540-1544) shows encouraging similarities.