Additional lichen records and mineralogical data from metal-contaminated sites in Maine

Geochemistry and mineralogy of rocks play important roles in the occurrence of individual lichen species and assembly of lichen communities. Whereas lichens of metal-enriched settings have been a focus of study for many decades, only a few such lichen inventories exist for North America. We reexamined the lichen biota of Pine Hill, a serpentine outcrop on Little Deer Isle, Maine and Callahan Mine, a copper- and zinc-enriched Superfund site in Brooksville, Maine, by conducting additional field surveys and reexamining unidentified taxa from previous collections. To better characterize the substrates upon which the lichens were found, we conducted elemental analyses via x-ray fluorescence and inductively coupled plasma-mass spectrometry on rock samples collected at Pine Hill and recorded pH, electrical conductivity, and elemental concentrations via inductively coupled plasma mass spectrometry on soil samples from Callahan Mine. The re-investigation of lichens of the two metal-enriched sites resulted in the addition of 20 taxa to Pine Hill and 10 taxa to Callahan Mine. These include Dermatocarpon leptophyllodes, Placynthiella hyporhoda, Pyrenocarpon thelostomum, and Vezdaea acicularis, all recorded for the first time from New England. In addition, we report the first documented records since the late 19th to early 20th century for New England of Porocyphus coccodes, Sarcosagium campestre, and Steinia geophana, and the first such record for Maine for Coccocarpia palmicola. Stereocaulon condensatum and S. subcoralloides, both considered rare in New England, were also collected from Callahan Mine.