79ft 



Plants — Our Lniitf^ Rt'MHiives 



Fig. 2. Documented lichen desert 

 in the United States and Canada. 

 Strong anecdotal evidence exists 

 that lichen deserts also occur in 

 most major cities. 



For further information: 



James P. Bennett 



National Biological Service 



Wisconsin Cooperative 



Research Unit 



University of Wisconsin-Madison 



Madison, Wl 53705 



Copperhill. Tennessee (Mather 1978). and in 

 Canada in Montieai (LeBlunc and De Sloover 

 1970) and Sudbury (LeBlanc et al. 1972) (Fig. 

 2). In some of ttiese areas, researchers estimate 

 that as much as 80%-90'7f of the original lichen 

 flora is gone (Nash 1975: Wetmore l989). Acid 

 rain has diminished lichen diversity in remote 

 rural areas such as north-central Pennsylvania 

 (Showman and Long 1992), central and south- 

 western Connecticut (Metzler 1980), and south- 

 western Louisiana (Thompson et al. 1987). 

 Sensitive species must be studied and moni- 

 tored to determine the effects of air pollutants. 



Some lichens are unique to old-growth 

 forests. Usnea loiiiiissiina. which only grows in 

 old-growth spruce forests, has vanished from 

 many sites in western Europe (Esseen et al. 

 1992) and may be repeating this pattern in pails 

 of the United States. Other old-growth forest 

 lichens, including Alcctoria sanneulosa. 

 Lobaha scwhiculaui. and Runuilina lliniii.ski. 

 are now quite rare in the eastern United States 

 because of habitat destruction and loss. 



In addition, .scientific overcollecting may 

 become a problem for lichens. One species, 

 Gymnodenna liueare, was overcollected in 

 Great Smoky Mountains National Park, 

 Tennessee, in the late 1970's, and is now pro- 

 posed for federal listing as endangered. 

 Collecting is no longer allowed in certain areas 

 (e.g., some national parks and nature preserves), 

 and both the American Bryological and 

 Lichenological Society and the British 

 Lichenological Society do not always permit 

 collecting at popular sites during their annual 

 forays. Some hobby overcollecting of lichens 

 for dye materials or architectural tree models is 

 thought to be a problem in a few areas, but is not 

 well documented. 



Trends in lichenology in this country are not 

 encouraging and are at odds with trends in the 

 rest of world (Galloway 1992). With fewer uni- 

 versities offering training in the discipline. 



fewer surveys and lists of floras being done, less 

 literature being published, and at the same time 

 lichens disappearing from our ecosystems, it is 

 clear that the science is heading the opposite 

 direction of what is needed. Other countries, 

 including England, Canada, the Netherlands, 

 and Japan, are increasing funding for lichenolo- 

 gy, training more students, publishing more lit- 

 erature, and conserving their lichen tlora. Given 

 the problems confronting lichen habitats, the 

 size of the United States, and the potential flora 

 it may have, lichen science needs more atten- 

 tion. A reasonable start would be a preliminary 

 checklist for every state and an identification of 

 priority areas for future surveys. 



References 



Egan, R.S. IQ87. A fifth checklist of the lichen-forming, 

 lichenocolous and allied fungi of the continental United 

 States and Canada. Bryologist 90:77-173. 



Esseen. R-A.. B. Ehnstrom. L. Ericson, and K. Sjoberg. 

 1992. Boreal forests — the focal habitats of fennoscandia. 

 Chapter 7 in L. t-!ansson. ed. Ecological principles of 

 nature con.servation. Elsevier, London. 



Galloway, D.J. 1992. Biodiversity: a lichenological per- 

 spective. Biodiversity and Conservation 1:312-323. 



Hale. M.E. 1979, How to know the lichens. 2nd ed. Wm. C. 

 Brown Publishers. Dubuque, lA. 246 pp. 



Johnson. D.W. 1979. Air pollution and the distribution of 

 corticolous lichens in Seattle. Washington. Northwest 

 .Science 53(4):257-263. 



LcBlanc. F., and J. De Sloover 1970. Relation between 

 industrialization and the distribution and growth of epi- 

 phytic lichens and mosses in Montreal. Canadian Journal 

 of Botany 48:1485-1496. 



LeBlanc. R. D.N. Rao. and G. Comeau. 1972. The epiphyt- 

 ic vegetation of Popuhis hatsumifem and its significance 

 as an air pollution indicator in Sudbury. Ontario. 

 Canadian Journal of Botany 50:519-528. 



Mather, T.C. 1978. Lichens as indicators of air pollution in 

 the vicinity of Copperhill, Tennessee. Georgia Journal of 

 Science 36:127-139 



Metzler. K.J. 1980. Lichens and air pollution: a study in 

 Connecticut. Report of Investigations 9. State Geological 

 and Natural History Survey of Connecticut. 30 pp. 



Nash. T.H., III. 1975. Influence of effluents from a zinc fac- 

 tory on lichens. Ecological Monographs 45:183-198. 



Pittam. S.K. 1991. The rare lichens project, a progress 

 report. Evansia 8:45-47. 



Saunders. J.R. 1976. The influence of SO-, on corticolous 

 lichens in Cedar Rapids. Iowa. Submitted in partial ful- 

 fillment for College Honors (Biology) al Coe College, 

 Cedar Rapids. lA. May 1976. 1 1 1 pp. 



Showman. R.E.. and R.P. Long. 1992. Lichen studies along 

 a wet sulfate deposition gradient in Pennsylvania. 

 Bryologist 95:166-170. 



Sigal. L.L.. and T.H. Nash III. 1983. Lichen communities on 

 conifers in southern California mountains: an ecological 

 survev relative too.xidant air pollution. Ecology 64:1343- 

 1354.' 



Thompson. R.L., G.J. Ramelow, J.N. Beck. M.P. Langley, 

 and J.C. Young. 1987. A study of airborne metals in 

 Calcasieu Parish. Louisiana using the lichens. Pannelia 

 praesorediosa and RamaUna stenospora. Water. Air and 

 Soil Pollution 36:295-309. 



Wetmore, CM. 1988. Lichens and air quality in Indiana 

 Dunes National Lakeshore. Mycota.\on 33:25-39. 



Wetmore, CM. 1989. Lichens and air quality in Cuyahoga 

 Valley National Recreation Area, Ohio. Bryologist 

 92:273-281. 



