For the University plant biology professor, the majesty is in the lichen that he finds sprinkled across landscapes. For most of his 40-year career, Wetmore has collected more than 80,000 lichen samples from national parks to study. In recent years, he and others have used the lichens to monitor the levels of air pollution.
Lichens are symbiotic, non-vascular organisms, similar to fungi or moss.
There are more than 20,000 types of lichens throughout the world, with 550 types in Minnesota alone. The value for air quality studies stems from lichen's sensitivity to changes in the air's composition, Wetmore said. Lichens are very reactive to the presence of sulfur dioxide in the air, which is a by-product released from smoke stacks. Within a 50-mile radius of smoke stacks, some species of lichen die due to the poor air quality. Through studies of the plant, pollution control officials can determine if the air is worsening in those areas.