Table 9 — Analysis of variance and multiple comparisons for relative cover after trampling and after 1 year 

 of recovery in Colorado's Rocky Mountains 



After trampling After 1 year 



Source 



df 



F 



P 



df 



F 



P 



Number of passes 



3 



201.6 



0.0001 



3 



20.4 



0.0001 



Vegetation type 



3 



48.6 



.0001 



3 



95.4 



.0001 



Interaction 



8 



1.5 



.18 



8 



11.2 



.0001 



Significantly different treatments 



Number of passes 25>75>200>500 25>75>200>500 



Vegetation types^ K,D>V>G D,K,G>V 



'Vegetation types: K = Kobresia, D = Danthonia, V = Vaccinium, G = Geranium. 



cover when trampled (fig. 11). Relative cover decreased 

 to 62 percent after 25 passes and to only 10 percent after 

 200 passes. The Vaccinium type dominated by dw^arf 

 shrubs was significantly more resistant. Relative cover de- 

 creased to 51 percent after 200 passes and 17 percent after 

 500 passes. More resistant still were the matted forbs and 

 graminoids of the Trifolium meadow and Kobresia turf 

 vegetation types. In the Trifolium type, relative cover de- 

 creased to 54 percent after 200 passes and 26 percent after 



500 passes. In the Kobresia type, relative cover decreased 

 to 61 percent after 200 passes and 39 percent after 500 

 passes. In these latter two types, relative cover on lanes 

 trampled 75 times or less was not significantly different 

 from the control. 



One year after trampling, disturbance could not be 

 detected on any of the Trifolium or Geranium lanes. 

 Both had substantially recovered. Considering that 

 Geranium was the type most disturbed after trampUng, 



100 200 300 400 500 100 200 300 400 500 



Number of Passes 



Figure 11 — Relative vegetation cover after trampling and after 1 year of recovery 

 in four vegetation types in Colorado's Rocky Mountains. Vertical bars represent 

 1 standard error above and below the mean. 



18 



