1201- 



(0 



81 100 



(0 

 (0 

 Q. 



m 



CM 



o 



< 



(D 

 > 

 O 



o 

 o 



1 20 

 o 



80 



60 



40 



Sibbaldia 



Erigeron 



Geum\ 



Fragaria 



• Wo/a 



• Achillea 



• Geranium 



Thermopsis 



. Vaccinium 



• Kobresia • Carex 

 9TriTolium dasyphyllum 

 \9Danthonia 



^Tri folium parry i 

 ^Potentilla 



1 



1 



J 



20 40 60 80 100 120 



Relative Cover After 500 Passes 



Figure 16— Relative cover after light and 

 heavy trampling for abundant species in 

 four vegetation types in Colorado's 

 Rocky Mountains. 



c 

 o 

 o 



o 100 



y-Geum 



Danthonia/rP°^^'"'"^ 

 Trifolium p^ryi / ^/ f Fragaria 



Vnfo//um ''Acliillea 

 • dasyphyllum 

 Sibbaldia 



Geranium^ • Viola 

 • Erigeron 



• Thermopsis 



100 80 60 40 20 

 Relative Cover After Trampling (percent) 

 Resistance Index 



Figure 18 — Resistance, tolerance, and resil- 

 ience of abundant species in four vegetation 

 types in Colorado's Rocky Mountains. Resil- 

 ience is indicated by the perpendicular dis- 

 tance from the diagonal line of equal resis- 

 tance and tolerance. 



(0 



<u 



(0 

 0) 

 (0 

 Q. 



in 



CM 



k_ 



< 



> 

 o 

 o 



o 

 > 



o 

 QC 



160 

 140 

 120 

 100 

 80 

 60 

 40 

 20 



*Vaccinium 



Trifolium parry i 



*Geum 



• Fragaria Trifoliurn 

 ^ ^ . ^Carex ^ dasyphyllum 

 Kobresiam • .^m"^^ Aster 



Danthonia^ * ^^'^'^ 

 Geranium • mPotenWIa 



Sibbaldia Achillea 



• Erigeron 



*Viola 



Thermopsis 



-L 



± 



20 40 60 80 100 120 



Relative Cover After 500 Passes 



Figure 17 — Relative cover 1 year after light 

 and heavy trampling for abundant species in 

 four vegetation types in Colorado's Rocky 

 Mountains. 



EFFECTS OF TRAMPLING 

 IN THE WHITE MOUNTAINS 



The study sites in the Northeast were all located in 

 the White Mountain National Forest in northern New 

 Hampshire. The sites were along the eastern flank 

 and summit of the Presidential Range, near the Great 

 Gulf Wilderness. Two sites were in northern hard- 

 wood forests at low elevations (450 m) close to the 

 West Branch of the Peabody River. On one site, soils 

 appeared to be saturated with water throughout the 

 year. Overstory trees were moderately dense (70 per- 

 cent cover) and diverse, with Betula lutea (yellow 

 birch) and Acer rubrum (red maple) most abundant. 

 The ground cover was tall, dense, and diverse (fig. 

 19A). The most abundant species were Leersia 

 oryzoides (cutgrass), Viola pallens (northern white vio- 

 let), and Onoclea sensibilis (sensitive fern). This veg- 

 etation type was not vvddely distributed, but appeared 

 to be representative of poorly drained sites in hard- 

 wood forests. 



The other low-elevation site was well drained most 

 of the year, although it was flooded seasonally by the 

 Peabody River. Both low-elevation sites had been 

 logged 75 to 100 years ago. The tree canopy was 

 dense (85 percent cover) and diverse. Conifers (red 

 spruce — Picea rubens, balsam fir — Abies balsamea. 



25 



