Mountain Pine Beetles
Found in the northwestern US and western Canada, native Mountain Pine Beetles and similar species are thriving in the milder winters attributed to climate change and are expanding their reach into areas that were previously too cold to inhabit. Although outbreaks have occurred in the past, recent infestations have been the worst in recorded history. Photo evidence of beetle outbreaks may be documented as the evergreen pines and spruce turn red and die from the beetle attacks.
Warmer winters speed up the beetle’s reproduction cycle and reduce cold-related mortality, thus increasing the number of trees infested and killed. Studies* show that beetle attacks may decrease the potential for forests to act as carbon sinks, further contributing to the accumulation of atmospheric carbon dioxide. The dead trees resulting from beetle infestation also provide fuel for forest fires.
Other insect species are also likely to expand their ranges due to climate change. Many are vectors for a variety of human diseases.
Pine Beetle Resources:
Forest Health: Mountain Pine Beetles, by the National Park Service
Hoyle, Brian. 2008. “Plight of the pines.” Nature Reports Climate Change 2: 52-53.
* Kurz, W.A. et al. 2008. “Mountain pine beetle and forest carbon feedback to climate change.” Nature 452: 987-990.