Table 20 — Percent bare ground before and after trampling and after 1 year of recovery for four vegetation 

 types in North Carolina's Great Smoky Mountains^ 



Number of passes 









25 



75 



200 



500 



Carex pensylvanica 



(beech forest) 

 Before trampling 

 After trampling 

 After 1 year 



50 (7)2 

 48 (9) 

 43 (8) 



55 (6) 

 59 (9) 

 54 (4) 



49 (5) 

 66 (4) 

 51 (7) 



46 (6) 

 76 (1) 

 60 (6) 



44 (2) 

 88 (2) 

 66 (9) 



Potentilla simplex 



(old-field) 



Before trampling 

 After trampling 

 After 1 year 



9(4) 

 8 (3) 

 11 (2) 



14(4) 

 do (lU) 

 10(4) 



11 (3) 



39 (7) 

 8(3) 



9(3) 

 66 (7) 

 6(3) 



15(3) 

 88 (1) 

 28 (7) 



Amphicarpa bracteata 

 (cove hardwood forest) 

 Before trampling 

 After trampling 

 After 1 year 



14(3) 

 14 (1) 

 18(4) 



14(3) 

 41 (9) 

 26 (7) 



19(4) 

 74 (6) 

 44(7) 



14(1) 

 88 (3) 

 45 (5) 



26 (7) 

 94 (4) 

 69 (5) 



Dryoptehs campyloptera 

 (subalpine forest) 



Before trampling 



After trampling 



After 1 year 



5(2) 

 2 (1) 

 2 (1) 



5(3) 

 64 (9) 

 2(1) 



4(2) 

 88 (5) 

 16(6) 



3(2) 

 93 (1) 

 20 (9) 



3(1) 

 99 (1) 

 27 (9) 



'Percent bare ground is the mean proportion of each quadrat that is not vegetated. 

 ^Standard errors are in parentheses. 



dominated by fems {Dryopteris), and one type codomi- 

 nated by forbs and graminoids {Potentilla). In contrast 

 to the other regions, no types occurred above tree line. 

 One type w^as in subalpine forest, two types were in 

 low-elevation forest, and one type was a low-elevation, 

 partially forested type. A list of the most abundant 

 species can be found in the appendix. Nomenclature 

 follows Radford and others (1968). 



Bare Ground and Vegetation Cover 



Before trampling, the Dryopteris type (subalpine for- 

 est) was densely vegetated (mean bare ground of 4 per- 

 cent). The Carex type (beech forest) was sparsely veg- 

 etated (mean bare ground of 49 percent), while the 

 Potentilla type (old-field) and Amphicarpa type (cove 

 hardwood forest) were intermediate in cover (mean 

 bare ground of 12 and 17 percent, respectively). Tram- 

 pling exposed substantial amounts of bare ground on 

 all vegetation types (table 20). In the densely vege- 

 tated Dryopteris type, for example, bare ground was 

 64 percent after 25 passes, 88 percent after 75 passes, 

 and 99 percent after 500 passes. The 500-pass lanes 

 were nearly barren in all four vegetation types. 



During the year following trampling, vegetation 

 cover increased on all of the trampled lanes. However, 

 few of the trampled lanes approached original condi- 

 tions in three of the four types. In Amphicarpa and 



Dryopteris, only the 25-pass lanes were similar to origi- 

 nal conditions. In Carex, the 25-pass and 75-pass 

 lanes approached original conditions. In Potentilla, 

 all lanes except the 500-pass lanes approached origi- 

 nal conditions. 



Relative cover after trampling differed significantly 

 with the amount of trampling and with the vegetation 

 type. The interaction between these effects was not 

 significant (table 21). After the year of recovery, dif- 

 ferences between tramphng levels and vegetation types 

 were stiU significant. However, the difference was not 

 as great and fewer differences were significant. The 

 interaction was still not significant. Relative cover 

 after the year of recovery was higher in Dryopteris 

 than in Amphicarpa. This was the only significant 

 difference among vegetation types. 



Of the four vegetation types, the fern- and forb- 

 dominated Dryopteris type lost the most vegetation 

 cover (fig. 29). Relative cover decreased to 33 percent 

 after just 25 passes and to 4 percent after 200 passes. 

 The graminoid-dominated Carex type was the most 

 resistant. The relative cover after 25 passes was not 

 significantly different fi-om the cover on control lanes, 

 decreasing to 45 percent after 200 passes. The forb- 

 dominated Potentilla and Amphicarpa types had simi- 

 lar responses that were intermediate. Relative cover 

 after 25 passes was 63 and 45 percent, respectively; 

 after 200 passes it was 15 and 12 percent. Differences 



38 



