Understanding mixed severity fire regimes: A role for flammability strategies?

Plant flammability and local species composition can control fine scale variation in fire regime. Across species, flammability is multi-dimensional with at least two orthogonal axes of variation: total heat release and flame spread rate. In the US Southwest, however, we understand variation in litter flammability better than we do variation in crown flammability. I argue that species-specific flammability strategies are a potential source of variation in local fire behavior in the forests and woodlands of the US Southwest and a contributor to the "mixed severity" regimes typical of these systems.