Pine beetles thick as rain clouds over British Columbia
Posted: September 12, 2012Source: Missoulian
If you thought the beetle-killed forests in Montana look bad, check out the Idaho-sized hole they’ve chewed in BritishColumbia.
Investigative reporter Andrew Nikiforuk brought some equally massive metaphors to describe the impact the insect “the size of a mouse turd” has had on Canadian ecology and politics. The combination of high-grade logging for spruce and fir and drought conditions has increased British Columbia’s lodgepole pine population from 17 percent to 53 percent of the provincial forest in the last few decades.
And that’s attracted swarms of mountain pine bark beetles so large, they get mistaken for rain clouds on airport radars in Prince George, B.C. The combined weight of beetles in the infestation over Homer, Alaska, equaled 3,300 killer whales, or half a million wolves flying over the forest.
“We never thought there might be another forest manager in the woods,” Nikiforuk said during an afternoon lecture at the University of Montana on Wednesday. “But they co-evolved with conifers over 300 million years. They can create massive transformations of the landscape faster than we can. We need hydrocarbons to do all that – beetles don’t.”
Mountain pine bark beetles are part of some 7,000 beetle species that live in coniferous forests, although only 10 or so are the tree-killing variety. UM entomology professor Diana Six said new research shows the interaction of beetles and trees to be much more complex than previously imagined.
It’s commonly known that mountain pine bark beetles attack pine trees, burrowing inside to lay eggs. Those larvae give off a fungus that turns the wood blue. The tree dies in the process.
What researchers now know is the beetles carry a host of even smaller mites, worms and fungal spores that all work together in the beetle’s life cycle. The fungus releases nitrogen from the core of the tree in huge amounts, which the beetles feed on. In essence, Six said, they farm their fungus inside the tree.
But it’s the initial invasion of the tree by adult beetles that essentially kills the tree. They bore holes in the bark. The tree responds by using pitch and sap to push the beetles out. If enough beetles pile on, they can overwhelm a tree’s defensive system within hours. Then they spend the next two to five years living off the remains.
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Nikiforuk spent much of the past 20 years covering the Canadian energy economy. While taking a break from that politically charged topic, he started noticing the impact bugs were having on his own property in southwestern Alberta. He ended up publishing the results of his inquiry in “Empire of the Beetle: How Human Folly and a Tiny Bug Are Killing North America’s Great Forests.”
He also authored “The Energy Slaves: Oil and the New Servitude,” which investigates the Canadian petroleum industry. On Wednesday, he presented the President’s Lecture at UM’s University Center Ballroom.
Nikiforuk recounted how for the past decade, British Columbia forestry leaders have tried a variety of ways to combat the beetle outbreak, from squirting trees with arsenic to wrapping them with explosives. They also tripled the allowable annual timber harvest to gather beetle-killed trees before they lost commercial value.
Now that policy has prompted a provincial government plan to log nature preserves and park lands in order to keep harvests at their artificially accelerated levels, he said.
One irony of the situation, Nikiforuk said, was that Canada has had one of the longest-running scientific forest management programs in the world, thanks to its centuries-old heritage as a timber producer. But the federal government killed that program in 1996, just as all data was pointing toward a major catastrophe in forest development.
As a result, even though British Columbia has a decade’s head-start on dealing with the beetle outbreak, it now lacks any dependable lessons learned to share with Montana and other U.S. regions, Nikiforuk said.
“About the only thing you can say is ‘let it be,’ ” he said. “A beetle-killed forest still holds water and soil. It still holds carbon. It will regenerate. But we tend to over-manage. Where we suppress volatility and diversity, we create vulnerability.”