Zip,
Good point, although that's really for more arboreal forests, i.e. forests as in the Sierra or something similar. In chaparal, for example, there's no "crown" therefore no crown fires.
Joshua Tree used to be far more fire resistant in that vegetation was fairly isolated. A fire typically wouldn't spread far because the fire couldn't spread from isolated clump to isolated clump across bare ground. Unfortunately, non-native grasses have been introduced to Joshua Tree. These grasses provide a "fire path" that allows fires to spread. Fires now destroy Joshua Trees, Pinyon Pines, Quercus Turbinella (that's an Oak whose common name escapes me), etc. that take years and years to grow. I'm not a fire expert, so there may be some benefit to more frequent fires in Joshua Tree, but J Tree does not fit the profile of an arboreal forest where more frequent fires are beneficial in that they prevent crown fires. Ain't no crown in Joshua Tree!
Just some thoughts. Don't have the answers. Hate to see old growth "trees" burn under any circumstances.
HJ