Chronology of an Epidemic

Historically the mountain pine beetle’s primary host has been the lodgepole pine. In the north, where lodgepoles dominate the landscape, cold temperatures helped keep beetle populations in check; down south the insects had far fewer trees to infest. With forests increasingly warmed by climate change, the beetles are thriving in once inhospitable areas, attacking species of pine they rarely touched before—and drastically altering the landscape.

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Martin Gamache, NGM Staff; Shelley Sperry. Sources: Canadian Forest Service; Barbara Bentz and Jeanine Paschke, U.S. Forest Service; Aaron McGill, Alberta Environment and Sustainable Resource Development; Tim Ebata, British Columbia MFLNRO; Allan Carroll, University of British Columbia; Brian Aukema, University of Minnesota