Bioassessing air pollution effects with epiphytic lichens in Raleigh, North Carolina, U.S.A

Abstract

Abstract Lichen diversity and coverage on willow oaks were measured in 16 parks in the Raleigh area of North Carolina, plus one natural area in nearby Orange County (control), as a pilot study for a potential statewide lichen biomonitoring project. This study's objectives were to assess the air pollution effects of the Raleigh urban airshed on these lichen communities, and determine what methods are best for this bioassessment. Thirty-one macrolichens and 24 crustose lichens were detected with average trunk floras of 4–20 taxa per site. Lichen communities were dominated by: Buellia curtisii, Candelaria concolor, Candelariella reflexa, Lecanora strobilina, L. hybocarpa, Physcia millegrana, Pyxine subcinerea and Punctelia rudecta, of which the macrolichen species are known to be pollution-tolerant, including Py. subcinerea, which is here described as such. The control site largely lacked these species, and harbored lichens more representative of nearby protected forests. All sites lacked pollution-sensitive...