America’s Disappearing Forests
Mountain pine beetle (MPB), Dendroctonus ponderosae, is native to the forests of western North America. Periodic outbreaks of the insect, previously called the Black Hills beetle or Rocky Mountain pine beetle, can result in losses of millions of trees. Outbreaks develop irrespective of property lines, being equally evident in wilderness areas, mountain subdivisions and back yards. Even windbreak or landscape pines many miles from the mountains can succumb to beetles imported in infested firewood.
Mountain pine beetles develop in pines, particularly ponderosa, lodgepole, Scotch and limber pine. Bristlecone and pinyon pine are less commonly attacked. During early stages of an outbreak, attacks are limited largely to trees under stress from injury, poor site conditions, fire damage, overcrowding, root disease or old age. However, as beetle populations increase, MPB attacks may involve most large trees in the outbreak area. Mountain Pine Beetle Fact Sheet
A video from the NY Times explaining how the mountain pine beetle, an insect pest, is destroying massive swaths of American lodgepole pine. Watch the video here
The tiny beetle, the shape and size of a grain of rice and native to the western part of North America, lays its eggs under the bark of mature lodge-pole pine and jack pine trees. Once the insects are embedded, a tree’s fate is sealed.
Healthy forests are normally carbon sinks, meaning that they absorb more carbon dioxide, the number one greenhouse gas, than they give off. When trees die, however, they release large amounts of pent up CO2 into the atmosphere, and leave fewer living plants to soak it up.
Researchers from the Canadian Forest Service have studied the relationship between the carbon cycle and forest fires, logging and tree deaths. They concluded that by 2020 the pine beetle outbreak will have released 270 megatonnes of carbon dioxide into the atmosphere from Canadian forests. There is yet to be an accepted study of the carbon cycle effect over a future period of time for North American forests.[Wikipedia]
