Literature Cited 



areas. In the case of black crowberry, 

 tolerance of trampling stress may 

 have been further reduced by salt and 

 wind stress and possibly wave action. 

 Black crowberry is a tundra plant 

 which, in Maine, is at the southern 

 end of its range. It is typically found 

 on exposed seaward-facing shores of 

 the Maine coast (Conkling 1981). On 

 Trails I and J, bayberry was able to 

 recover, possibly because it had no 

 competitors. 



In conclusion, most of the island 

 plant species studied were able to 

 recover from low levels of trampling 

 if allowed a recovery period of at least 

 1 year. In general, island climatic 

 conditions appear favorable for rapid 

 recovery. The species that were found 

 to be most resistant to low-level tram- 

 pling stress were red spruce and 

 Cladina spp. (on zero percent slope). 



Those particularly susceptible 

 to trampling damage were the woody 

 shrubs; black crowberry, bayberry, 

 and horizontal juniper, which were 

 growing on exposed sites with thin 

 soils. Recovery for these species is 

 relatively slow. The treadways formed 

 after 100 to 200 passes remained 

 visible even after 2 years of recovery. 

 The tall herbaceous species rough 

 goldenrod and sarsaparilla are also 

 intolerant to trampling stress. 



It is apparent that trampling 

 damage can occur at very low levels 

 of use and that recovery periods vary 

 according to morphological charac- 

 teristics of species and site-specific 

 factors. In general, treadways became 

 visible between 40 and 80 tramples 

 and remained the same width (ap- 

 proximately 30 cm) with additional 

 trampling. Further research is needed 

 on the long-term effects of low-level 

 trampling. The results of this study 

 indicate that managers should locate 

 trails away from island species such 

 as black crowberry, horizontal juniper, 

 and bayberry growing on exposed 

 sites. Such exposed sites appear to 

 be highly stressed in an island envi- 

 ronment. In particular, an unusual 

 species such as black crowberry 

 should be protected. 



Burden, R. F.; Randerson, P. F. Quan- 

 titative studies of the effects of 

 human trampling on vegetation as 

 an aid to the management of semi- 

 natural areas. Journal of Applied 

 Ecology 9:439-457; 1972. 



Conkling, P.W. Islands in Time. Cam- 

 den, ME: DownEast Books; 1981. 



Crum, H. Mosses of the Great Lakes 

 Forest. Ann Arbor, Ml: University 

 Herbarium, University of Michigan; 

 1973. 



David, R. B. Spruce-fir forests of the 

 coast of Maine. Ecological Mono- 

 graphs 36:79-94; 1966. 



Fernald, Merritt Lyndon. Gray's Man- 

 ual of Botany, 8th Ed. New York: 

 American Book Company; 1950. 



Frenkel, R. E. Ruderal vegetation 

 along some California roadsides. 



University of California Public 

 Geography 20:1-163; 1970. 



Hale, M. E. How to know the Lichens. 



2nd Ed. Dubuque, lA: Wm. C. Brown 

 Company; 1979. 



Hill, A. F. The vegetation of the Pen- 

 obscot Bay region, Maine. In: Pro- 

 ceedings, Portland Society of 

 Natural History; 1923(lll):306-438. 



Holmes, Daniel 0.; Dobson, Heidi E. M. 

 Ecological carrying capacity re- 

 search, Yosemite National Park. 



Part 1. Springfield, VA: U.S. Depart- 

 ment of Commerce, National Tech- 

 nical Information Service No. PB-270 

 955; 1976. 247 p. 



McBride, J. C; Leonard, R. E. A sys- 

 tem for measuring groundcover 

 changes. Parks 7(1):20; 1982. 



McLane, C. B. Islands of the Mid- 

 Maine Coast: Blue Hill and Penobs- 

 cot Bays. Woolwich, ME: Kennebec 

 River Press; 1982. 



Studlar, S. M. Trampling effects on 

 bryophytes: Trail surveys and ex- 

 periments. The Bryologist 83(3): 

 301-313; 1980. 



Thornthwaite, C. W. An approach 

 toward a rational classification of 

 climate. Geographical Review 38: 

 55-94; 1948. 



The Authors 



R. E. Leonard is Project Leader 

 of the Backcountry Research Project, 

 USDA Forest Service, Northeastern 

 Forest Experiment Station, Durham, 

 New Hampshire. P. W. Conkling is 

 Director of the Island Institute, 

 with the Hurricane Island Outward 

 Bound School, Rockland, Maine, J. L. 

 McMahon is a biological technician 

 with the Backcountry Research Proj- 

 ect in Durham. 



Manuscript received for 

 publication 16 July 1984 



tr U.S. GOVERNMENT PRINTING OFFICE: 1985— 505 028/543 



6 



