Fire awakens a primal fear of death, triggering the flight response in birds and animals.
Those with wings or legs, will run or fly away, leaving their nests and burrows in order to survive. Trees can't run. A tree or plant must stay, attached to the ground as the flames roar toward it, as its neighbors die, as its bark begins to warm then sizzle, as flames explode up its sides and blast into its needles, as it is consumed in an inferno, giving its life-stuff back to a cycle of carbon. There is a moment in a forest fire when a tree actually dies. By the following day, there is nothing left of the tree but a few shovels of dead and dying embers and a thick layer of ash on the ground awaiting a cycle of regrowth.