THE AUTHORS 



DAVID N. COLE is research biologist and Project 

 Leader for the Intermountain Station's Wilderness Man- 

 agement Research Work Unit at the Forestry Sciences 

 Laboratory, Missoula, MT. He received his B.A. degree 

 in geography from the University of California, Berkeley, 

 In 1972. He received his Ph.D. degree, also in geogra- 

 phy, from the University of Oregon in 1977. He has 

 written many papers on wilderness management, par- 

 ticularly on the ecological effects of recreational use. 



RESEARCH SUMMARY 



This study examined the response of vegetation to 

 experimental trampling that simulated the effects of hik- 

 ing. A total of 1 6 different vegetation types were studied 

 in mountainous regions of Washington, Colorado, New 

 Hampshire, and North Carolina. Changes in vegetation 

 cover, vegetation height, species richness (the number 

 of species), and species composition were evaluated. 

 This provided a unique opportunity to compare trampling 

 impacts in different parts of the country and to assess 

 factors that influence the durability of vegetation. The 

 most significant findings were: 



1 . Most vegetation types had substantially less cover 

 and were substantially shorter after being trampled just 

 75 times. However, in most types the number of species 

 did not decline, nor did the species composition shift 

 except at higher levels of trampling. 



2. Some vegetation types were highly resistant to 

 trampling. The most resistant vegetation type could 

 absorb 25 to 30 times as much trampling as the least 

 resistant type, with no more damage. 



3. Differences among the responses of vegetation 

 types were greatest shortly after trampling. However, 

 a few types remained substantially more impacted than 

 others 1 year after trampling. 



4. The responses of vegetation types varied more 

 within any part of the country than among regions. 

 Moreover, the types of vegetation that were the most 

 resistant or the most resilient were similar across the 

 country. A larger proportion of the vegetation types in 

 the mountainous Western United States appeared to be 

 more resistant to trampling than vegetation types in the 

 Eastern States. 



5. Alpine vegetation, at least the types included in 

 this study, was more resistant to trampling than many 

 vegetation types found at lower elevations. 



6. The best predictors of resistance were (a) whether 

 the vegetation was dominated by shrubs, forbs, or gram- 

 inoids, and (b) whether the vegetation was erect or not. 

 The least resistant plants were erect forbs and ferns. 

 The most resistant plants were caespitose (tuft-forming) 

 and mat-forming graminoids (grasses, sedges, and 

 rushes). 



7. The best predictor of resilience was whether or 

 not the vegetation was dominated by chamaephytes — 

 plants that regenerate from tissues (such as buds) 

 above ground. Chamaephytes, most of which were 

 short shrubs, were substantially less resilient than 

 hemicryptophytes — plants with growing points at the 

 soil surface — and cryptophytes — plants with growing 

 points at or below the ground surface. 



These results should help managers predict the ef- 

 fects of various levels of wilderness use. They should 

 also help managers assess the relative durability of dif- 

 ferent vegetation types. 



ACKNOWLEDGMENTS 



I am grateful to many people who assisted with this 

 study. For assistance in the field, thanks to Lisa 

 Campbell, Bart Johnson, Burnham Martin, Debbie 

 Overton, and Sue Trull. 



Intermountain Research Station 

 324 25th Street 

 Ogden, UT 84401 



