Pine beetles are a natural part of the ecosystem and have been for millions of years. They play an important ecological role attacking old and weak trees, facilitating the growth of younger, stronger trees. Thickening forests in recent decades due to wildfire suppression and restrictions on active forest management, have created ideal conditions for pine beetles and pine beetle infestations. Warmer temperatures may play a role, although the impact of warmer temperatures is speculative. Spruce beetles, for example, have long thrived in cold climates such as Alaska.
