Disrupted Forests

A hotter climate in western mountains is already promoting the spread of tree-killing bark beetles. Beetles now are spreading to higher elevations than before and reproducing more quickly. In areas that used to be so cold that it took three years for one generation to produce another, it now takes just one year. As a result, the West is experiencing an uprecedented infestation of bark beetles. The worst is in Colorado, where the U.S. Forest Service says, bark beetles "will likely kill the majority of Colorado's large diameter lodgepole pine forests within the next 3 to 5 years." A more accurate statement would be that a majority of the large diameter trees will be killed. Still, that is a large impact on Colorado's mountains.

Climate disruption is affecting western forests in other ways. Something scientists have dubbed "sudden aspen decline" is reducing aspen stands across the West, triggered by the hotter and drier conditions that is the manifestation of climate change here. Other scientists have discoverd increased death rates among trees of all types and ages across the West, linked to higher temperatures.

“[C]ool temperatures are believed to be the major restriction on
mountain pine beetle outbreaks at high elevations . . . Generally,
warmer temperatures promote bark beetle outbreaks both through
their favorable influence on the life cycle of the insect and through
drought-related declines in the trees’ abilities to withstand attack.”

U.S. Climate Change Science Program
Rocky Mountain/Great Basin Regional
Climate-Change Assessment (2003)