UNH Researchers Using Lowly Lichens To Gauge The Effects Of Air Pollution On Vegetation

That's why Barry Rock, UNH associate professor of natural resources, and graduate student Katrina Maloney focus part of their research on lichen, which can be found on rocks, trees -- even roof shingles.

Lichen -- plants which are a combination of alga and fungus -- are good bio-indicators of changes in air quality because they absorb what's in the air -- for better or worse, says Maloney. An area with plentiful lichen, for example, means air quality is acceptable; those areas devoid of lichen have high levels of sulfur dioxide, lead or other air pollutants.

Maloney and Rock will be among the scientists taking part in the New England Regional Climate Change Impacts Workshop, scheduled for Sept. 3-5 and sponsored by the university's Institute for the Study of Earth, Oceans and Space. Representatives from the six New England states and upstate New York, which share one general climatic region, are being invited to attend.

The workshop is part of a federal initiative to define the nation's research agenda in the area of climate change. Results from this and 15 other workshops across the country will be brought to the National Workshop on Climate Change Impacts set for November in Washington, D.C.

Maloney explains that her lichen research is yet another gauge of climate change.

Lichen do not absorb anything from their "hosts," such as rocks or trees. Like plants, they manufacture sugars through photosynthesis, Maloney explains, "but they also absorb what's in the air and store it."

An area's air quality is determined by the presence or absence of lichen and, Maloney adds, even what kind of lichen is present is important. It comes in three shapes: crustose, a crusty form that sits tightly against rock or tree; folise, more foliage like; and fruticose, shrubby, with 'fingers' pointing up. Crustose lichen generally is more tolerant of air quality changes, says Maloney, while fruticose, with more surface area, is the most sensitive.

Why is lichen important? Not only does it serve as an air quality indicator, it also is an important part of nutrient recycling in the forest and an important food source for caribou in the tundra.

It might take years for lichen to absorb enough sulfur dioxide, for example, to kill it, so Maloney's work has focused on finding ways to gauge damage before the lichen disappears. "We're trying to develop an early warning system," she says. "We'd rather find the damage sooner than later, and avoid a lichen desert."