What types of conditions are considered special in the context of fire fuels?

In the context of fire fuels, "special conditions" refer to factors that significantly influence fire behavior and fuel characteristics, particularly in ways that can lead to increased fire activity or unexpected fire behavior.

When considering firebrand sources and unusual fine fuels, these conditions play a crucial role. Firebrands are small burning materials that can be carried by wind and create spot fires beyond the main fire perimeter, leading to rapid fire spread and challenging suppression efforts. Unusual fine fuels, including atypical vegetation or debris that may ignite easily, can also contribute to unexpected fire behavior, making the fire more intense or difficult to control.

The other conditions listed, while they can influence fire behavior, do not fall under the category of special conditions directly impacting fuel characteristics in the same way. For example, high soil moisture and dense canopy can actually reduce fire behavior due to increased moisture levels and reduced light penetration. Warm temperatures and low wind speeds can lead to a more stable atmosphere, lessening fire intensity, and cool temperatures with heavy rain typically dampen fire activity significantly. Thus, the conditions encompassing firebrand sources and unusual fine fuels are distinctively significant for understanding and predicting fire behavior in wildland settings.