Bark Beetles and Wildfire

Bark beetles feed off of living trees. 

 

 Once the tree is infested, it dies, leaving it dry and susceptible to fire. Bark beetles and trees have had a symbiotic relationship in the past where the beetles would feed off a few trees and those trees would release seed for regrowth. That relationship is no longer the same as the climate is getting warmer, the bark beetle have been spreading to higher elevations and attacking trees that have not had a symbiotic relationship with them, leaving them vulnerable.

 In any case, once the trees are dead, they become fuel for fire.  If the bark beetle just left the remnants (saw dust) on the forest floor, the forest may be able to survive as the fuel would be just enough for a low-severity ground fire.

 However, the bark beetle can kill a tree, and the tree will still be standing, getting drier as it dies.  If there were a fire with many standing dead trees, these trees will ignite and cause high-severity crown fires, killing the entire forest.