Canopy base height [Fuel strata gap]
n. The lowest height above the ground above which there is sufficient canopy fuel to propagate fire vertically (Scott and Reinhardt 2001).
Canopy base height is a property of a plot, stand, or group of trees, not of an individual tree (see crown base height). For fire modeling, canopy base height is an effective value that incorporates ladder fuel, such as tall shrubs and small trees. No physical field measurement of canopy base height exists; therefore, different observers will estimate different values in the same stand.
The term canopy base height has origins in silviculture, where it may have different meaning. To avoid confusion, the wildland fire term “fuel strata gap” was coined and given the same definition as that for canopy base height shown here.