Earth Equity News

What's Killing the Great Forests of the American West? By Jim Robbins, YaleEnviro360, March 15, 2010. "Across western North America, from Mexico to Alaska, forest die-off is occurring on an extraordinary scale, unprecedented in at least the last century-and-a-half -- and perhaps much longer. All told, the Rocky Mountains in Canada and the United States have seen nearly 70,000 square miles of forest -- an area the size of Washington state -- die since 2000. For the most part, this massive die-off is being caused by outbreaks of tree-killing insects, from the ips beetle in the Southwest that has killed pinyon pine, to the spruce beetle, fir beetle, and the major pest -- the mountain pine beetle -- that has hammered forests in the north. These large-scale forest deaths from beetle infestations are likely a symptom of a bigger problem, according to scientists: warming temperatures and increased stress, due to a changing climate. Although western North America has been hardest hit by insect infestations, sizeable areas of forest in Australia, Russia, France, and other countries have experienced die-offs, most of which appears to have been caused by drought, high temperatures, or both."