Trampling Effects on Mountain 

 Vegetation in Washington, 

 Colorado, New Hampshire, 

 and North Carolina 



David N. Cole 



INTRODUCTION 



Recreational use inevitably alters vegetation in 

 natural environments. In wilderness, where main- 

 taining natural conditions is a management objective, 

 the impacts of recreation on vegetation are a serious 

 problem. These impacts can be minimal where visi- 

 tors stay on constructed trails and campsites that are 

 already heavily impacted. However, impacts occur 

 wherever visitors leave established trails and camp- 

 sites. In popular destination areas the results are 

 webs of social trails (trails developed by use) and ex- 

 cessive numbers of campsites. In remote, little-used 

 areas the results are trails and campsites that need 

 not have been created. 



To mitigate disturbance, managers need a better 

 understanding of (1) the relationship between the 

 amount of use and the amount of impact and (2) the 

 relative durabihty of different vegetation types. This 

 will allow them to predict the consequences of various 

 levels of use and to choose whether to concentrate or 

 disperse use. The understanding will improve their 

 ability to select durable sites for recreational use. 

 Finally, it will help them tell visitors where they can 

 camp or hike with the least damage to vegetation. 



Several research methodologies have been used when 

 studying the durability of sites and the relationship 

 between the level of use and impacts (see Cole 1987 

 for a review). The most effective way to isolate these 

 variables is through carefully designed experiments. 

 Experimental trampling studies can be traced back to 

 the early work of Bates (1935), although Wagar (1964) 

 was the first to report quantitative results following 

 controlled levels of trampling. Over the years, experi- 

 mental methods have evolved. The tendency for each 

 researcher to develop a unique methodology has made 

 it difficult to compare results from different studies. 

 Cole and Bayfield (1993) have suggested a standard 

 protocol that, if followed, would greatly increase the 

 comparability of results. 



This paper applies the Cole and Bayfield technique 

 in 16 vegetation types around the United States. The 

 objectives are to (1) describe the immediate response of 

 vegetation to different amounts of trampling, (2) de- 

 scribe vegetative recovery within 1 year of trampling. 



(3) assess the magnitude of difference in response 

 among vegetation types, and (4) evaluate the extent 

 to which variation in response can be explained by 

 regional, environmental, or plant characteristics. 



STUDY AREAS 



TrampUng experiments were conducted in mountain- 

 ous areas in four regions of the country — the Pacific 

 Northwest, the Central Rocky Mountains, the North- 

 east, and the Southeast. Each region contains substan- 

 tial wilderness acreage and receives heavy recreational 

 use. Experiments were conducted in four different 

 vegetation types in each region. 



All of the vegetation types were regionally abun- 

 dant and were selected to represent diverse environ- 

 mented and botanical characteristics. In each region, 

 vegetation types spanned a range of 800 to 1,200 m 

 elevation. Alpine communities, those above timber- 

 line, were studied in the three regions in which moun- 

 tains extend above timberline, the Pacific Northwest, 

 the Central Rocky Mountains, and the Northeast. 

 Nine of the vegetation types were in closed forest; 

 one was a dwarf-scrub community; and six were open 

 herbaceous communities (table 1). Closed subalpine 

 spruce-fir forests were examined in three of the four 

 study areas; in the fourth area — the Cascade Moun- 

 tains of the Pacific Northwest — two vegetation types 

 {Phyllodoce and Valeriana) occurred both within and 

 intermixed with spruce-fir forest. Deciduous forests 

 were examined in three of the four areas. 



Ground cover vegetation on the study sites showed 

 considerable diversity in growth forms and habits. 

 Since the groimd cover species are subject to most of 

 the disturbance from trampling and camping, their 

 characteristics largely determine the response of the 

 vegetation type. Three of the 16 types had a predomi- 

 nantly shrubby ground cover; six had predominantly 

 forbs (herbaceous plants other than ferns, grasses, 

 rushes, and sedges) or ferns; four had predominantly 

 graminoids (grasses, rushes, and sedges) and three had 

 a mixture of forbs and graminoids. The vegetation 

 types also varied in height and density. For example, 

 the dense Carex nigricans turf in the Cascades con- 

 trasted with the relatively sparse Carex pensylvanica 



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