This aerial photograph shows trees infested with the mountain pine beetle near Prince George. Photo by Dezene Huber.

For the past few years, British Columbia has been experiencing one of the worst environmental catastrophes in its history. Vast areas of pine forest in the interior of the province have been infested with a tiny insect, the mountain pine beetle ( dendroctonus ponderosae ). About the size of a grain of rice, the female beetle bores beneath the bark of a pine tree into the sapwood. Males follow, the beetles mate and the females deposit their eggs in the wood. When the eggs hatch, the larvae devour the living tissue of the tree, cutting off its supply of water and nutrients until it dies. As well, the beetles carry a fungus which they deposit in the wood, staining it blue. This bluestain fungus causes dehydration and weakens the trees' defences against further beetle assault. A year after they arrive, the beetles fly away in search of a new food source, spreading the contagion from tree to tree. As well as laying waste to vast stretches of forest, the infestation has denuded parks, golf courses and neighbourhood backyards throughout the Interior.

The progress of the disease is colour coded. The year following the initial attack the needles of an affected tree turn bright red, a sign that it is dying. Subsequently the colour fades to a dull red, the colour of brick, and by three or four years after attack, a tree has turned grey and lifeless. The result is an infestation that has destroyed close to one half of the province's pine forest. Particularly affected is the lodgepole pine, the Interior's most abundant commercial species. In 2006 a forest ministry survey recorded 9.2 million hectares of infected trees. It is the largest mountain pine beetle outbreak in Canadian history.

	To learn more about the mountain pine beetle infestation, consult these online resources: the BC Ministry of Forests and Range at www.for.gov.bc.ca the Canadian Forest Service's mountain pine beetle program at www.mpb.cfs.nrcan.gc.ca, and

The infestation has been blamed on global climate change. The mountain pine beetle is not a newcomer to British Columbia. They occur naturally in the province and have always been present, usually in older or weakened trees. In the normal course of events, they are killed off by persistent cold temperatures, which the Interior used to experience with regularity. A sudden cold snap (at least -25 degrees C) in the fall or spring, or a prolonged cold spell of -40 degrees C or lower would destroy the beetles. But for the past few years, mild winter temperatures in the Interior have allowed the beetles to survive and spread. Couple that with the fact that beetles thrive in mature pine and BC has more older pine than ever before and you have a recipe for environmental disaster. Barring a period of extremely cold weather, the Ministry of Forests predicts that half of the province's mature pine will be dead by 2008 and 80% by 2013.

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Paradoxically, even as it destroys the forest and attacks the livelihood of so many people who depend on logging, the epidemic has increased economic activity in affected communities. Despite its discoloration, the wood can still be used if it is harvested within two or three years of attack. The government has increased the allowable timber cut so that loggers may utilize the dead trees—"bugwood" as it is known—before they rot and lose whatever commercial value they still have. It's a gold rush, but instead of gold, the mother lode is the dead and dying pine forests of the Interior.

This flurry of activity will not last, however. When it ends, Interior communities will be hard hit as the forest industry, an economic mainstay for generations, goes into decline. Another threat is forest fires. Wild fires are part of the cycle of forest renewal. Old trees burn and are replaced by fresh new growth. As humans intervened to suppress fires in order to protect the valuable resource for harvesting, the forest grew older and more susceptible to the beetles, which prefer older stands of timber. Now the vast spaces of dead trees are tinder dry and a threat to explode into flame at the first lightning strike or careless camp fire. The decline of the pine forest will also have an impact on water quality and wildlife habitat. In many ways, we are only beginning to recognize the magnitude of the changes that the little bug will bring. And it is not confined to British Columbia. Already Alberta is battling the beetle, and experts fear the infestation may spread right across the northern boreal forest.