2012-11-27. Beetles Warm BC Forests

posted Nov 29, 2012, 11:23 AM by Alan Gould
| by Sabrina Richards, TheScientist. Relevant to Climate Change chapter 8, A New World View chapter 1, and Ecosystem Change chapter 4. Excerpt:  Pine beetle infestation increases the summertime temperatures of some Canadian forests by 1 degree Celsius—about the same impact as a forest fire—according to new findings published Sunday (November 25) in Nature Geoscience. The beetle populations, spurred into profusion by global warming, appear to be contributing to a temperature feedback loop, …. The results reinforce the conclusion that ecological disturbances like beetle infestations can have significant ecological impacts, said Allan Carroll, an insect ecologist at the University of British Columbia…. ”We have until very recently considered biotic disturbances a bit player [in climate change],” …. The current study confirms that pine beetles can have massive effects that set up “an uncomfortable feedback” wherein warming temperatures encourage more beetle damage, which in turn influences warming… Pine beetles lay their eggs under pine tree bark, introducing a fungus that inhibits nutrient flow in the trees. Usually pine beetles are killed off by freezing winter temperatures, limiting their spread. But a recent spate of warm winters, combined with forests dominated by mature pine trees, enabled a beetle population boom in North America, including parts of Alberta, Wyoming, and Colorado.  About 170,000 square kilometers of British Columbia’s forest—almost 20 percent of the province’s area—have been affected by pine beetle infestations, costing thousands of timber industry jobs. Many studies have focused on the role of global warming on pine beetle outbreaks, but fewer have looked at how the beetles themselves may be contributing to climate change…. Read the full article: http://www.the-scientist.com/?articles.view/articleNo/33447/title/Beetles-Warm-BC-Forests/