Wildland fire spread is determined by two-way feedbacks between fires and the surrounding atmosphere, which is influenced by the vegetation structure, nearby topography, and fire configuration as well as ambient wind conditions. The influences of wildland fire entrainment, fire-induced indrafts, is a critical aspect of fire behavior that is underrepresented in current operational fire spread models. The effectiveness of fuels management activities depends on the resulting wildland fire entrainment patterns. Safe use of prescribed fires typically depends on fire practitioner’s ability to anticipate the interaction of multiple fires. This interaction is tied to wildland fire entrainment and the competition between their fire-induced indrafts. Topography influences on fire behavior are also dominated by wildland fire entrainment patterns that control the patterns of heat transfer to unburned fuel. Multi-scale two-way fire/atmosphere feedbacks determine heterogenous fireline dynamics and thus fire spread, the effects of fires on ecology and the near-field lofting and transport of the smoke.