July 1, 2009

North America Could Face Massive Pine Beetle Infestation

Scientists fear that the swarms of mountain pine beetles that have killed more than half of all lodge pole pines in British Columbia may eventually make their way into forests in the US.

And while cold winters typically kill most of the beetle larvae, the region has recently witnessed unusually higher temperatures that have allowed the beetle to thrive for longer periods of time.

The beetle has recently been found in Alberta, and scientists told BBC News that they could threaten jack pine forests throughout North America.

"In places in Alberta there were stories of what they call beetle rain, where under a perfectly blue sky farmers would start hearing what sounded like rain on their tin roofs," Professor Staffan Lindgren, at the University of Northern British Columbia, told the BBC.

"It turned out it was beetles coming out and falling on the roofs, literally billions and billions of beetles."

The beetle kills trees by creating fungus under the bark, which inhibits growth and ultimately leads to its demise.

The lodge pole pine, which is used to build homes across the US, has even adapted to use forest fires to help it regenerate, Lindgren said.

"Lodge Pole pine has a cone that's adapted to fire," he said. "As fire goes through, it kills off all the other species, but actually aids in opening up the cone, and re-establishes pine as the dominant species. We've kept fire out of the ecosystem and created huge areas of mature lodge pole pine, which are ideal for mountain pine beetle."

Jim Snetsinger, chief forester with British Columbia's Ministry of Forests and Range, described the recent beetle population growth as the result of a "perfect storm of warm winters, very warm summers."

"The first phase is to detect and monitor the beetles. Second phase is to harvest affected areas as soon as possible so you can remove the beetles, and the last phase, which is what we're in at the moment, is to salvage as much timber as you can before it loses its economic value," he told the BBC.

Even in times of frigid temperatures, the beetle larvae have appeared to adapt and continued to keep themselves alive, said Dezene Huber at the University of Northern British Columbia.

"The insect is generally able to survive at temperatures as low as minus 37C, minus 40C starts to push it," Dr Huber told the BBC.

"My lab is looking at some of the genes involved in making glycerol, a particular component of the antifreeze that these larvae use. We're looking at the larvae in the autumn and the spring to see which genes are turned on and off in relation to glycerol production."

And now the beetle that has plagued forests in British Columbia and neighboring Alberta may have its sights set on the rest of North America, experts said.

"In Alberta, the neighboring province just to the east, you have lodge pole pine which they're attacking now, and then after that you have jack pine all the way across the continent, down through Ontario and even into places like New Jersey," said Jim Burrows, forest stewardship officer with British Columbia's ministry of forests and range.

"We know mountain pine beetles can survive and reproduce in jack pine, but we don't know how well they can do that. The question now is are they going to be able to exploit jack pine to the same degree that they exploited lodge pole pine?"


Image Caption: Close up of adult mountain pine beetle. Photo by Dion Manastyrski, Ministry of Forests, southern Interior Forest Region


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