Wildland fires are generally classified into three categories: ground fires, surface fires, and crown fires (Fig. 1). Soils are described worldwide by the various layers that have formed or been deposited on top of bedrock or other parent material. In wildland areas, the layer closest to the surface is composed of organic material deposited by plants (Foth 1978). The organic layer is divided into two parts – the O1 layer at the surface and the O2 layer which forms under the O1 layer. Ground fires burn the matted and decomposed organic material that forms the O2 layer. Surface fires burn the surface litter (O1 layer), other loose debris, and small vegetation. Crown fires burn through the living foliage and branches of trees and shrubs independently or coupled to a surface fire. Because the fire environment consisting of vegetative fuels, weather, and topography is complex and dynamic, these fire types often occur simultaneously within a wildland fire, and transitions between the fire types occur as fuels, weather, and topography change.