VANCOUVER (Reuters) - Alberta, one of two western Canadian provinces battling a more than decade-old infestation of mountain pine beetles, claimed progress in the fight on Tuesday but warned the war is not yet won.
The infestation in Alberta and British Columbia has cut into supplies of major forestry companies including West Fraser Timber Co, Canfor Corp, Tolko Industries and a host of independent sawmills.
Surveys indicate fewer trees were attacked in Alberta this summer than a year ago, and there were no migration of new beetles over the Rocky Mountains from British Columbia where the outbreak began in the mid-1990s, officials said.
Alberta credits the reduction on its aggressive efforts to remove attacked trees before the insects could spread again, as well as extreme temperature fluctuations last winter that increased the beetle’s natural mortality rate.
But officials warned pockets of infested trees remain uncut and the spread from British Columbia may resume next year.
“We had some success this year, but the battle is far from over,” said Mel Knight, Alberta’s sustainable resource development minister.
The small beetles, Dendroctonus ponderosae, lay eggs under the bark of mature lodge-pole pines, eventually killing them. Once beetles infest a tree in the summer, it cannot be saved, and the new insects spread again the next year.
The lumber remains usable, but loses its value the longer the dead tree remains in the forest. The beetle also spreads a fungus that can give the wood fiber a blue stain.
Pine beetles threaten up to 6 million hectares of forest in Alberta, and it has removed some 400,000 beetle-infested trees since 2006, an official said on Tuesday.
Although Alberta produces significantly less lumber than British Columbia, there has been concern beetles could continue spreading east through the boreal forest.
“It’s pretty critical that Alberta stop it,” said Paul Quinn, an forest industry analyst at RBC Capital
British Columbia, which has not yet released its 2010 survey results, but its 2009 survey estimated some 9 million hectares of pine forest had been attacked in that province.
Officials say the infestation has begun to wane in central regions of British Columbia, largely because so many trees in those areas have already been killed off, but the beetles continue to spread north.
British Columbia has encouraged lumber companies to cut beetle-killed trees, but the United States has accused it setting logging rates artificially low to subsidize sawmills in violation of the US-Canada softwood lumber trade agreement.
Alberta does not have the same stumpage system for beetle-attacked trees, an official said.
Canadian producers have also a growing market for beetle wood in China. A British Columbia-led industry trade mission to China last week resulted in sales of 418 million board feet of lumber, including beetle-wood, officials said.
Reporting by Allan Dowd, Editing by Frank McGurty