Experiments and modeling of fire spread through individual trees

Fire spread through suspended vegetation, such as tree crowns, is a basic component of wildland fires. Most models of fire spread do not resolve the burning of individual trees. Instead, fire spread through a forest canopy, representing a collection tree crowns in an average sense, is modeled. There are a number of fire problems where an understanding of fire spread at a level that includes individual trees is needed. Among these fire problems are: the effect of a fire on tree health, the influence of a given fuel treatment on fire intensity, and fire spread through the intermix of vegetation and structures in the wildland-urban interface (WUI). NIST currently has an experimental and modeling project that seeks to improve our understanding of WUI fires. In this talk a number of experiments on the burning of different sized trees will be described. The results of these experiments will be presented and compared to three-dimensional, physics based, computer simulations.