1 



120 I- 



100 

 80 



60 

 40 

 20 



> Mosses 



^Clintonia 



• Holcus 

 Panicum 



^Potentilla 

 • Viola 



*Thaspium 

 'Amphicarpa 



Dryoptehs 

 9l Geranium 



• Phlox 

 • Carex pensylvanica 

 • Carex swanii 



1 



X 



JL 



J 



20 40 60 80 100 



Relative Cover After 500 Passes 



Figure 34 — Relative cover after light and 

 heavy trampling for abundant species in 

 four vegetation types in North Carolina's 

 Great Smoky Mountains. 



160 1- 



0)140 - 

 (0 

 (0 

 (0 

 Q. 



120 

 100 

 80 

 60 



in 



CM 

 0) 



< 



o 

 > 

 o 

 o 



o 

 > 



% 40 

 0) 



= 20 



> Mosses 



• Holcus 



Clintonia* '^^^^P'"'"*» Panicum 



Carex pensylvanica Dryoptehs 

 * •. • Carex swanii 

 Potentillam \ 



Geranium 



• Phlox 



Amphicarpa 



• Viola 



J. 



_L 



_L 



X 



X 



X 



J 



20 40 60 80 100 120 140 160 



Relative Cover After 500 Passes 



Figure 35 — Relative cover 1 year after 

 light and heavy trampling for abundant 

 species in four vegetation types in North 

 Carolina's Great Smoky Mountains. 



maculatum (wild geranium) and Dryopteris campylop- 

 tera were the least resistant species, with relative 

 covers of 21 and 24 percent after just 25 passes. They 

 were among the most resilient species. 



A plot of response to light or heavy trampling reveals 

 a variety of initial responses (fig. 34). Most species 

 were arrayed along the left side of the graph. These 

 species did not resist heavy trampling; however, the 

 resistance to light trampling varied greatly. Carex 

 pensylvanica, Carex swanii, and Phlox stolonifera, 

 httle affected by light trampling, also survived heavy 

 trampling — to some extent. Mosses were the only 

 plants able to resist heavy trampling. 



A plot of relative cover after the year of recovery is 

 more linear, ranging from the mosses, which tolerated 

 light and heavy trampling, to Amphicarpa bracteata, 

 which was only moderately tolerant of even Ught tram- 

 pUng (fig. 35). Despite being relatively resistant, the 

 Carex species and Phlox stolonifera were relatively 

 intolerant because they did not recover much. 



Relationships between resistance, resilience, and 

 tolerance are more apparent in a plot of resistance and 

 tolerance indexes (fig. 36). The unique response was 

 that of the mosses, which were highly resistant, resil- 

 ient, and tolerant. At the other extreme was the twin- 

 ing herb, Amphicarpa bracteata, which had relatively 

 low resistance and resilience and, therefore, very low 

 tolerance. In contrast to the other study areas, the 

 graminoids were highly variable in their responses. 



100 80 60 40 20 

 Relative Cover After Trampling (percent) 

 Resistance Index 



Figure 36 — Resistance, tolerance, and 

 resilience of abundant species in four veg- 

 etation types in North Carolina's Great 

 Smoky Mountains. Resilience is indicated 

 by the perpendicular distance of the point 

 from the diagonal line of equal resistance 

 and tolerance. 



45 



