Lichens and air quality in Pictured Rocks National Lakeshore [FINAL REPORT]

Wetmore, Clifford

Lichens were collected from 24 locations at Pictured Rocks National Lakeshore, MI and from Kingston Lake near the lakeshore boundary. Sampling locations included various vegetational types throughout the park and targeted sites that a specialist would expect to be rich in lichens. Collections were made from disturbed and undisturbed areas. At some locations additional lichen thalli (bodies) were collected for chemical analyses. Field observations were made concerning the general health of the lichens. A species list includes 235 taxa with notes concerning the species' sensitivities to sulfur dioxide. The most common species in the Lakeshore and their habitats are discussed. The 13 species that are the most sensitive to sulfur dioxide are listed and discussed. Chemical analyses were done to detect the presence of several elements in 3 species. Specimens were dried and ground before analysis. Determination of levels of calcium, magnesium, sodium, potassium, phosphorus, iron, manganese, aluminum, copper, zinc, cadmium, chromium, nickel, lead, and boron was made by Inductively Coupled Plasma (ICP) Atomic Emission Spectrometry. Sulfur was determined by infrared absorption. The lichen flora in Pictured Rocks National Lakeshore was found to be diverse and not damaged by air pollution. Distribution maps for 14 species are included.