Monday, July 30, 2007

Pine beetles contributing to global warming?

Vancouver Sun: Could B.C.'s ever-expanding sea of red-tinged forests caused by pine beetle infestation be contributing to global warming? Researchers at the University of Northern B.C. think it's possible, with one professor now leading a study on whether beetle activity - long suspected as being caused by global warming because warmer winters can no longer contain their spread - is creating additional warming in its own right.

"By taking measurements at the same site over a number of years, we're able to track how a pine beetle-infected forest evolves from a sink for carbon to a source," said Art Fredeen, a UNBC professor of ecosystem science and management.

…Fredeen said that carbon dioxide is one of the main greenhouse gases, and that forests are known to store tremendous amounts of carbon acquired through photosynthesis. If the trees are cut down or are killed by the beetle, they can't absorb carbon anymore, and climate change may result.

"Clear-cutting can release enormous amounts of carbon to the atmosphere for 10 years or more after harvesting," said Fredeen in a statement. "The pine beetle infestation has led to very high levels of logging activity and we're interested in finding out what this activity will mean to levels of carbon dioxide in the atmosphere."

He is working with researchers from the University of B.C. and the ministry of forests to conduct studies at two sites north of Prince George: one near Crooked River Provincial Park and the other at Kennedy Siding east of Mackenzie. It's funded by the Canadian Foundation for Climate and Atmospheric Science and the B.C. Forest Sciences Program.

…Fredeen noted that during the past 150 years the levels of carbon dioxide in the atmosphere have risen considerably, with the burning of fossil fuels believed to be the main culprit. However, 25 per cent of the increase is due to deforestation, he added.

"The sheer scale of the pine beetle infestation means that salvage logging could have a real impact on the link between forests, harvesting and climate change," Fredeen said….

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