This guidance document is intended to serve as a resource for national park, forest, and refuge staff when considering lichen studies to address air quality concerns. It provides background regarding the use of lichens as air pollution indicators, their sensitivities to various air pollutants, and the effects of air pollution on lichen physiology, communities, and tissue chemistry. It discusses the types of information and objectives that can optimize the utility of lichen studies from an air management and air regulatory perspective. It also provides a checklist of questions to consider when designing or evaluating the potential of.
