LichensThis article is part of a larger document. View the larger document here.
The status of epiphytic ( i.e., tree-dwelling) lichen communities is systematically tracked by the Forest Inventory and Analysis (FIA) and national Forest Health Monitoring (FHM) programs of the Forest Service, U.S. Department of Agriculture ( http:// fia.fs.fed.us/lichen/default.asp). Lichens are highly sensitive to climatic and chemical perturbations, and can be used for early detection of changes in climate and air quality (Jovan 2008). This forewarning gives land and air managers the opportunity to attempt mitigation before less sensitive organisms and ecosystem processes are affected. Monitoring to ensure maintenance of intact lichen communities likewise has direct consequence for forest health due to the ecological linkages of the lichen communities to other forest flora and fauna (http:// www.lichen.com/fauna.html). Such linkages include provision of critical winter forage for ungulates, camouflaging nesting material for many species of bird and rodent, and fixation of atmospheric nitrogen (N) into a form useable by plants (Nash III 1996).