Lichen Biomonitoring Project
Introduction Lichen bioindicators Study objectives Participating park units Study methods Site descriptions Study results Literature Web resources (managed by ABLS) Lawrey lab home	Lichens have been recognized as indicators of air quality since the late 19^th Century (Nash and Wirth 1988, Gries 1996, Henderson 2000). Many species are known to be especially sensitive or tolerant of certain air pollutants, and others are known to accumulate pollutant elements directly from the atmosphere. Given the usefulness of lichens as bioindicators, the National Park Service (NPS) and other U.S. federal agencies have undertaken many lichen studies on federal lands during the past thirty years (Geiser and Reynolds 2002). Over 30 lichen biomonitoring programs that have been done in areas managed by the NPS. In the National Capital Region (NCR), a number of lichen biomonitoring efforts have already been done during the past 30 years. The present study expands these efforts by establishing over 100 permanent biomonitoring sites in nine national parks in the NCR to detect and describe air pollution effects with the ultimate goal of protecting NCR resources. At each permanent study site, the abundance of all tree-inhabiting (corticolous) macrolichens has been recorded and a sample of a single common species has been taken for elemental analysis. Results are adding to information already obtained and serving as a basis for future monitoring of air quality in the NCR.