R egion 



▲ Colorado 

 • Washington 

 O New Hampshire 

 A North Carolina 



Relative Cover After Trampling (percent) 

 Resistance Index 



Figure 38 — Resistance, tolerance, and 

 resilience of vegetation types in each of 

 the four regions. Resilience is indicated 

 by the perpendicular distance from the 

 diagonal line of equal resistance and tol- 

 erance. Refer to figure 37 for names of 

 each vegetation type. 



was least resistant. Trifolium w^as most resilient. 

 Pachistima was least resilient. Trifolium was most 

 tolerant. Vaccinium was least tolerant. 



Regional Differences — Most research on the 

 impacts of vidlderness use has been conducted in 

 the Western United States and northern Minnesota. 

 Managers of areas in the Eastern United States have 

 questioned whether those results apply in eastern 

 areas. Growdng conditions are often more favorable 

 there, leading some to suggest that impacts might 

 be less severe. One study of campsite impacts in east- 

 em areas, using techniques directly comparable to 

 those used in western areas, found little difference 

 between East and West (Cole and Marion 1988). 



Analysis of variance was used to determine whether 

 or not these attributes differed significantly with re- 

 gion or with environmental or plant characteristics. 

 The analysis found that the Colorado and Washington 

 vegetation types included in this study were signifi- 

 cantly more resistant than the New Hampshire and 

 North Carolina types. The four most resistant vegeta- 

 tion types were located in Colorado and Washington 

 (fig. 38). Despite this general tendency, there was 

 more variation v^dthin regions than among regions. 

 For example, the Geranium and Valeriana types in 

 Colorado and Washington were not resistant, and the 

 Carex bigelowii and Carex pensylvanica types in New 

 Hampshire and North Carolina were quite resistant. 

 Each region had a graminoid-dominated type that 

 was quite resistant and one or more types dominated 

 by erect forbs that were not resistant. There were no 



significant differences, among regions, in resilience 

 or in tolerance. 



The results of this study are influenced by the spe- 

 cific vegetation types selected for study. However, 

 these res;ilts do confirm the earUer campsite study in 

 which vegetation types in eastern areas were no more 

 tolerant of trampling than those in western areas. 

 Both western and eastern areas have some vegeta- 

 tion types that are resistant and others that are fi*ag- 

 ile. If anything, these results suggest that eastern 

 areas have a greater proportion of fi*agile types. This 

 may reflect the prevalence of environmental conditions 

 that favor erect forbs — a plant grov^^h form that is 

 generally not resistant. Variation among vegetation 

 types was less pronounced in the eastern areas than 

 in the western areas. 



Elevation — ^Another common generaUzation is that 

 vegetation durabUity decreases as elevation increases; 

 therefore, alpine vegetation would be particularly fi'ag- 

 Ue. The data fi'om these 16 vegetation types suggest 

 the opposite. Alpine vegetation types were significantly 

 more resistant than subalpine and low-elevation types 

 (fig. 39). In the three regions with an alpine zone, the 

 vegetation type located above timberline was the most 

 resistant to trampling. Resihence did not vary signifi- 

 cantly with elevation, despite suggestions that resil- 

 ience might decrease at higher elevations (Cole 1987). 

 Tolerance was greatest in alpine vegetation types and 

 least in subalpine types. 



The resistance of alpine vegetation is not likely to 

 be a direct effect of elevation. It is more likely to re- 

 flect the kinds of plants that grow above timberline. 



zone 



line 



Relative Cover After Trampling (percent) 

 Resistance Index 



Figure 39 — Resistance, tolerance, and 

 resilience of vegetation types in different 

 elevation zones. Resilience is indicated 

 by the perpendicular distance from the 

 diagonal line of equal resistance and tol- 

 erance. Refer to figure 37 for names of 

 each vegetation type. 



49 



