From my hiking blog …
A mountain pine beetle infestation has already killed off billions of trees in British Columbia, Canada.
The mountain pine beetle epidemic in British Columbia is coming to a close, but only because the pests are running out of food, a forestry representative says.
The latest figures from the B.C. government and the Council of Forest Industries estimate the beetles have infested more than half of B.C.’s marketable pine forest. …
The beetles kill the trees by boring through the bark into the phloem layer on which they feed and in which eggs are laid. Pioneer female beetles initiate attacks, and produce pheromones which attract other beetles and results in mass attack.
The trees respond to attack by increasing their resin output in order to discourage or kill the beetles, but the beetles carry blue stain fungi which, if established, will block the tree resin response. Over time (usually within 2 weeks of attack), the trees are overwhelmed as the phloem layer is damaged enough to cut off the flow of water and nutrients.
In the end, the trees starve to death, and the damage can be easily seen even from the air in the form of reddened needles. Entire groves of trees after an outbreak will appear reddish for this reason. Usually older trees die faster. After particularly long and hot summers mountain pine beetle population can get out of hand and that’s when there starts to be a problem. There are too many beetles and they start killing off big areas of trees.
Prince George, British Columbia – dead and dying trees – flickr – D&J Huber
Is there any hope?
I don’t know. I would think some predator would take an advantage of the infestation.
Cold winters can stifle infestations. But we’ve had record warm winters of late where I live. (A cold snap we had in 2008 might help.)
Rocky Mountain National Park in Colorado used selective burning to try to stem the beetles.
Alberta is trying some preemptive prescribed burns.
Others are clear cutting though there’s very little demand for the wood.