What caused the current bark beetle outbreak?
The current level of bark beetle mortality has resulted from a combination of natural factors including, but not limited to: drought, dense forest stands, shallow/rocky soils, and relatively large quantities of bark beetles. Human activities such as fire suppression, past forest management practices, past grazing practices, and ongoing urbanization also have also contributed to current conditions. These factors all influence the amount of water, light, and nutrients available to individual trees in the forest. Trees not receiving enough of these resources become stressed. Bark beetles can detect stressed, susceptible trees and they respond by colonizing it and effectively removing it from the population. This inadvertently makes a larger quantity of resources available for the surviving trees, shrubs, and herbaceous plants.
