The Canary Report

Our lichen kin are in trouble

Posted on Oct 06, 2008 by Susie Collins in Blog, Environment

Lichens may be canary in the coal mine

SEVEN-MILE HILL, Ore. — On a bluff overlooking The Dalles, Ore., and the east end of the Columbia River Gorge, Forest Service scientist Linda Geiser [at left] and two assistants climb out of their rig and set to work.

Geiser and graduate student Peter Nelson begin dismantling black plastic tubes called passive samplers that have gathered data on the nitrogen content of rain and fog at the site for the past three years.

Grad student Larissa Lasselle grabs two sample bags and heads downhill into a thicket of ponderosa pine and oak. Her job: to collect lichens from tree branches for laboratory analysis.

It was at this site that Geiser, a Forest Service ecologist, collected some of the first evidence that air pollution was damaging the gorge environment. The messenger — like a canary in a coal mine — was the community of lichens that grows here, both those that flourish and those that fail to thrive.

Lichens are neither plants nor animals. They belong to the fungi family, but are actually part fungus, part alga. They come in many shapes and colors, and reproduce both sexually and asexually. They can dissolve rock, survive severe cold, and remain dormant for long periods.

But for Geiser, their most useful characteristic is their sensitivity to nitrogen and acid rain, major forms of pollution in the gorge.

The Seven-Mile Hill site is 62 miles west of Portland General Electric’s Boardman, Ore., coal-fired plant, the largest source of nitrogen oxide and sulfur dioxide in the eastern gorge. Near the coal plant is a sprawling dairy feed lot, a major source of ammonia that contributes to acid rain and fog.

Together, those sources are responsible for most of the air pollution that blows west into the gorge during winter months.

Link to full story at columbian.com

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Tags: Air, Environment, Pollution, Research, Toxic