United States 

Department of 

Agriculture 

Forest Service 

Intermountain 

Forest and Range 

Experiment Station 

Research Paper 

INT-284 

January 1982 

Wilderness 

Campsite 

Impacts: 

Effect of Amount 

of Use· 

David N. Cole 

This file was created by scanning the printed publication.

Errors identified by the software have been corrected;

however, some errors may remain.
THE AUTHOR 

Dr. DAVID N. COLE is a research ecologist with the Intermountain Station's Wilderness Management research work 

unit at the Forestry Sciences Laboratory on the University 

of Montana campus, Missoula. He is on temporary loan to 

the Forest Service from the Geography Department, 

University of Oregon, Eugene. Or. Cole received his B.A. 

degree in geography from the University of California, 

Berkeley, in 1972. He received his Ph.D., also in geography, 

from the University of Oregon in 1977. He has written 

several papers on the impacts of recreational use on 

wilderness soils and vegetation. 

RESEARCH SUMMARY 

Campsites that were located near subalpine lakes in the 

Eagle Cap Wilderness, Oreg., were studied. Research 

objectives were to determine what ecological changes had 

occurred on the sites, the extent to which amounts of 

change increased with increasing use, whether lakeshore 

sites had been more highly altered than sites set back from 

lakeshores at least 200 ft (61 m), and the sensitivity of 

selected indicators of ecological change. 

Significant changes on campsites, as compared to 

adjacent control plots included various types of 

damage to mature trees; loss of seedlings; loss of undergrowth vegetation; change in the species composition of 

this undergrowth; an increase in bare mineral soil; 

decrease in duff depth; a reduction in infiltration rates; an 

increase in pH and the concentrations of magnesium, 

calcium, and sodium ions; an increase in soil organic 

matter; and an increase in soil bulk density. No difference 

in the coh~entrations of potassium, phosphate, nitrate, 

and total nitrogen or in soil texture could be established. 

Of the 20 documented types of change, seven were more 

pronounced on more heavily used sites. Of these seven, 

loss of seedlings and loss of undergrowth vegetation were 

almost as pronounced on light-use sites as on moderateor heavy-use sites, despite the statistical significance of 

the relationship. The change in species composition of 

the undergrowth, percent bare mineral soil, percent of 

trees with exposed roots, and size of the barren campsite 

core were significantly less on light-use sites than the 

moderate- or heavy-use sites which had experienced 

similar amounts of change. Heavy-use sites differ from 

moderate-use sites primarily in the depth of the duff. This 

implies that most of the change which is likely to occur on 

these campsites can result from use of the site just a few 

times-per-year. 

Campsites set back from lakeshores had experienced 

as much change as lakeshore sites. This implies that 

lakeshore sites are not inherently more fragile. Where· a 

lakeshore setback policy exists, other justifications for this 

policy should be given. 

The campsite condition class rating developed by S. S. 

Frissell proved to be the most sensitive indicator of impact 

tested. Problems with this rating system, along with 

suggested modifications, are discussed. 

CONTENTS 

Page 

INTRODUCTION .................................. 1 

PREVIOUS STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

STUDY AREA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

FIELD METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

DATA ANALYSIS .................................. 9 

RESULTS AND DISCUSSION ...................... 10 

How Much Change Has Occurred on 

the Campsites? ................................ 10 

To What Extent Do Impacts Vary with 

Differences in Amount of Use? ................. 15 

How Much Change Occurs in Other Environmental 

Situations? .................................... 22 

Are Lakeshore Sites Particularly Fragile? ......... 25 

EVALUATION OF IMPACT INDICATORS .......... 26 

CONCLUSIONS AND MANAGEMENT 

IMPLICATIONS ................................. 28 

PUBLICATIONS CITED ............................ 31 

APPENDIX: THE DISTRIBUTION OF VASCULAR 

PLANT SPECIES ENCOUNTERED ON 

CAMPSITES OR CONTROL PLOTS .............. 33 

ACKNOWLEDGMENTS 

I am grateful to many people for help with this study. Jim 

Benedict, Sue Lindgren, Nancy Richardson, and Leslie 

Underhill helped in the field work. Randel Washburne 

provided computer assistance. Charles Feddema and 

Peter Stickney identified some of the more difficult plant 

specimens. 

The use of trade, firm, or corporation names in this 

publication is for the information and convenience of the 

reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture of 

any product or service to the exclusion of others which may 

be suitable. 
United States 

Department of 

Agriculture 

Forest Service 

Intermountain 

Forest and Range 

Experiment Station 

Wilderness 

Campsite 

Impacts: 

Effect of Amount 

of Use 

Research Paper 

INT-284 

January 1982 

INTRODUCTION 

David N. Cole 

Along with recent increases in recreational use of 

wilderness has come an awareness that this use has 

already modified pristine ecosystems intended for preservation. In many areas, the most severe impacts occur on 

campsites where use is highly concentrated, both spatially 

and temporally. Managers are understandably concerned 

about the,highly altered conditions of many campsites, as 

it is their responsibility, according to the Wilderness Act 

of 1964, to manage wilderness areas so that "natural 

conditions" are preserved and "the imprint of man's work 

(remains) substantially unnoticeable." 

It is commonly assumed that campsite impacts are the 

result of excessive use and that predicted future increases 

in use will cause increasingly severe degradation. A 

common response to this situation is an attempt to disperse 

users from areas of concentrated use to less frequently 

visited parts of the wilderness. Currently, 53 percent of all 

designated wilderness units in the Forest Service and Park 

Service attempt to disperse use. 1 While dispersal may 

decrease campsite use and visitor encounter frequencies 

in areas of heavy use, it can also increase the number of 

areas where one can expect to encounter other parties, 

and the number of areas which show the effects of 

recreational use. This reduces the proportion of the 

wilderness that offers opportunities for solitude and 

shows no substantial evidence of human impact. 

In order to evaluate the appropriateness of use dispersal 

in various wilderness situations, or to develop any other 

information-based wilderness campsite management 

policy, we need a better understanding of the changes 

occurring on campsites and the extent to which differences 

in amounts of use affect campsite condition. A study was 

designed to provide information of this kind for campsites 

in Eagle Cap Wilderness in northeastern Oregon. 

Permanent sampling plots were established on campsites 

so that long-term changes could be evaluated. This report 

describes results of the first year of study, an assessment 

of changes which have already occurred, and how these 

changes are related to the amount of use the site receives. 

The study also compares the amount of change which 

has occurred on lakeshore campsites and campsites 

located more than 200 ft (61 m) from a lake. There is a 

1 

common assumption that lakeshores are more fragile than 

sites set back from lakes. Currently, 34 percent of all 

designated wilderness units in the Forest Service and Park 

Service have regulations prohibiting camping within a 

certain distance of lakes. This is a sizable percentage, as 

only slightly more than half of the areas in the wilderness 

system contain bodies of water larger than 1 acre 

(McCurdy 1977). In the case of Eagle Cap Wilderness, a 

200-ft (61-m) setback has been established. 

The final objective was to test the sensitivity of indicators 

of impact that could be used to monitor overall site 

condition. Managers have increasingly recognized the 

value of monitoring systems for providing baseline 

information to help them evaluate their management 

programs and to identify areas where additional management actions need to be taken. Recently, monitoring has 

been mandated by Congress in the National Forest 

Mangement Act. In this study, we examined the ability 

of several individual measures to predict overall site 

conditions and amount of change. 

PREVIOUS STU Dl ES 

Most detailed studies of campsite impact have been 

conducted on developed campsites which are accessible 

by car and which receive much heavier use than most 

wilderness campsites. Backcountry campsites have been 

studied in northern Minnesota (Frissell and Duncan 1965; 

Merriam and others 1973), the mountains of the eastern 

United States (Rechlin 1973; Bratton and others 1978), 

Washington (Thornburgh 1962; Schreiner and Moorhead 

1976), Idaho (Coombs 1976), and Montana (Fichtler 1980). 

Of these studies, only Coombs (1976) and Fichtler (1980) 

provide detailed data for a low-use area typical of most of 

the wilderness in the United States. 

Most studies of backcountry campsites have 

documented a loss of vegetation cover and an increase 

in bare ground. Changes in species composition have been 

described in considerable detail (Thornburgh 1962; 

1 Data from a census of wilderness managers are on file at the Forestry 

Sciences Laboratory. Missoula. Mont. 
Coombs 1976; Cole 1977), as have mechanical damage to 

mature trees (Merriam and others 1973, Rechlin 1973, 

Fichtler 1980) and the almost complete elimination of 

tree seedlings (Frissell and Duncan 1965, Coombs 1976, 

Cole 1977, Fichtler 1980). Other noted changes include 

an increase in soil compaction (Thornburgh 1962, 

Merriam and others 1973, Cole 1977, Fichtler 1980), a 

reduction in infiltration rates (Frissell and Duncan 

1965), a loss of organic surface horizons (Frissell and 

Duncan 1965), and erosion resulting in the exposure of 

tree roots (Merriam and others 1973, Cole 1977, Fichtler 

1980.) 

In studies on developed campsites, an increase in pH 

also has been a consistent finding (Young and Gilmore 

1976; Dawson and others 1978; Rutherford and Scott 

1979). Changes in soil nutrient concentrations have been 

less consistent. Young and Gilmore (1976) found 

increases in calcium (Ca), potassium (K), phosphorus (P), 

sodium (Na), and nitrogen (N), and no change in 

magnesium (Mg) concentrations on campsites in 

Illinois. Working in southern Ontario, Rutherford and 

Scott (1979) found decreases in nitrate (N03), increases 

in chloride (C I), and no change in phosphate (P04), 

Mg, K, and sulfate (S04) concentrations on campsites. 

Conflicting results have also been found where soil 

organic matter has been studied. Dotzenko and others 

(1967), Settergren and Cole (1970), Dawson and others 

(1978), and Rutherford and Scott (1979) found decreases 

on campsites, while Young and Gilmore (1976) and 

Monti and Mackintosh (1979) found increases. 

In one of the few studies to relate amount of use to 

backcountry campsite condition, Frissell and Duncan 

(1965) found that more heavily used campsites in the 

Boundary Waters Canoe Area had less ground-cover 

vegetation and more tree root exposure than lightly 

used sites. They found no relationship, however, between 

amount of use and either vegetation loss (a measure 

based on a campsite-control comparison) or bare ground. 

Fichtler (1980) compared impacts on lightly and heavily 

used sites in Montana. He found no statistically significant 

differences in amount of change in the understory, 

overstory, or soil compaction. The only significant 

difference was in the amount of bare soil exposed. 

Merriam and others (1973), working in the Boundary 

Waters Canoe Area, found a poor relationship between 

amount of use and a summary measure of campsite 

impact. When sites were stratified by vegetation type, a 

more consistent relationship appeared; in each vegetation 

type, impact increased with use. The functional relationship was hyperbolic rather than linear, however, with the 

rate of increase in impact decreasing as use increased. 

Similar conclusions about the nature of the relationship 

between use and impact are evident in the data presented 

by Rechlin (1973) for backcountry campsites in the 

Adirondacks and by Dotzenko and others (1967), LaPage 

(1967), Young and Gilmore (1976), Legg and Schneider 

(1977), Young (1978), and James and others (1979) for 

developed campsites. Although overall impact generally 

increases as use increases, changes in many variables, 

such as infiltration rates (James and others 1979), 

soil organic matter (Dotzenko and others 1967; Young and 

Gilmore 1976), and soil pH (Young and Gilmore 1976) are 

not significantly correlated with amount of use. For those 

2 

variables in which amount of impact does increase with 

use, near-maximum levels of impact are usually achieved 

even with light use, and further increases in use do little 

to aggravate the severity of these impacts (fig. 1). 

1-

u 

<( 

a... 

~ 

Light Moderate 

AMOUNT OF USE 

Figure 1.--Typical research results for 

the relationship between campsite 

impact variables and amount of use. 

The response of variables as use 

increases from no use to light use is 

poorly understood. 

• 

Heavy 

In support of this conclusion, some of the most 

pronounced differences between sites which receive 

different amounts of use were found in the lightly used 

Idaho Primitive Area (Coombs 1976). In comparison to 

light-use sites, heavy-use sites had considerably less 

vegetation cover and considerably more erosion pavement. 

This study in Eagle Cap Wilderness differentiates 

between impact on lightly, moderately, and heavily used 

sites which would all have been considered lightly used 

sites in all of the studies other than those of Coombs 

(1976) and Fichtler (1980). This focuses attention on 

that part of the use spectrum which is most poorly understood (where use differences have the most pronounced 

influence on amount of impact) and which is most 

applicable to the wilderness situation. 

STUDY AREA 

The Eagle Cap Wilderness was selected for study 

because it contained numerous examples of campsites 

which receive light, moderate, and heavy use, in locations 

where at least ordinal estimates of use could be obtained. 
Furthermore, in terms of both use and environment, the 

area seemed to be representative of many heavily 

glaciated, mountainous wilderness areas in the National 

Forest System. 

The Eagle Cap Wilderness encompasses 293,735 acres 

(118 870 ha) of the Wallowa Mountains in northeastern 

Oregon (fig. 2). Jagged ridges tower more than 3,280 

ft (1 000 m) above deep glacial valleys which radiate from 

the granitic central core of the range. Several peaks 

approach 10,000 ft (3 000 m) in elevation, while the 

lowest elevations in the area are under 3,600 ft (1 100m). 

Over 13,000 visitors entered the Wilderness in 1978 and 

accounted for about 83,000 visitor-days of use. The 

distribution of use was highly concentrated, with most 

visitors attracted to the more than 50 lakes scattered 

through the subalpine zone (fig. 3). One area of about 

2,500 acres (1 000 ha), the Lake Basin, contains 10 major 

OREGON 

lakes and was visited by one of every three visitors to the 

Wilderness in 1978. Other lakes are more isolated and 

reached by less frequently traveled trails. A few lakes 

are still trailless. Twenty-two of the 26 campsites 

selected for study were located at subalpine lakes where it 

was possible to obtain an ordinal estimate of amount of use. 

The forest overstory at all sites was dominated by Abies 

lasiocarpa2 (subalpine fir), in conjunction with Picea 

engelmannii (Engelmann spruce), Pinus contorta (lodgepole pine), and Pinus albicaulis (whitebark pine); the 

understory was usually dominated by Vaccinium 

scoparium (grouse whortleberry). By confining the sample 

to campsites near lakes located between 7,050 and 

7,800 ft (2 150 and 2 400 m) in an Abies /asiocarpa/ 

Vaccinium scoparium forest type. on soils derived from 

granitic bedrock, environmental differences were kept to a 

minimum. Controlling environment in this manner permits 

the effects of differences in amount of use to be more 

precisely delineated. Four additional campsites, two in 

sedge meadows above 7,800 ft (2 400 m) in elevation and 

two in forests below 6,500 ft (1 981 m) in elevation, were 

studied for comparative purposes. 

2 All nomenclature follows Hitchcock and Conqu1st (1973) 

50 100 150 km 

50 100 miles 

1 Figure 2.--The Eagle Cap Wilderness is in northeastern 

N Oregon. 

Figure 3.--Subalpine lakes are the primary destination of most visitors to the 

Eagle Cap Wilderness. 

3 
The amount of use each site receives had to be estimated 

because no campsite-specific use data existed. This was 

accomplished by assigning each lake to either a heavy-, 

moderate-, or light-use category on the bases of observations and travel zone use data. The most prominenP 

forested site at each lake, usually located close to where 

the main trail first reaches the lake, was chosen as the site 

most representative of the amount of use the lake receives. 

The study sites consisted of six light-use sites, six 

moderate-use sites, and 10 heavy-use sites, five within 

200 ft (61 m) of a lake and five more than 200 ft (61 m) 

from a lake (fig. 4-7). Sites within 200ft (61 m) of a lake 

3Prommence was defmed primarily in terms of location. We chose the site 

we subjeCtively determined to be the s1te most arriving parties would 

choose. We avoided automatically choosing the most heavily impacted s1te 

on the iake to avoid the common circular argument 1n which heavily 

impacted Sites are subjectively assigned to the heavy-use category and then 

heavy-use s1tes are found to be heavily impacted 

-have traditionally been the most popular and are still 

frequently used, despite their having been officially closed 

to camping for the last few years. 

Although all analyses treated these use differences as 

merely ordinal estimates, an estimate of actual amount 

of use is valuable for comparative purposes. Observations 

suggest that most of the light-use sites are used less 

than five nights per year, with some of them receiving no 

use during some years. Most moderate-use sites probably 

are used 10 to 20 nights per year, while most heavy-use 

sites are used 25 to 50 nights per year. 

LOCATION OF SAMPLE CAMPSITES 

Lake A mount of Use 

1. Tombstone, moderate 

2. 01 ive, I ight 

3. John Henry, moderate 

4. Bear, light 

5. Wood, moderate 

6.Chimney, heavy 

7.Chimney, heavy 

8. Wild Sheep, light 

9. Blue, moderate 

10. Hidden, light 

11. Moon, I ight 

12. Minam, heavy 

13. Mirror, heavy 

14. Horseshoe, heavy 

15.Pocket, light 

16. Horseshoe, heavy 

17. Moccasin, heavy 

18. Moccasin, heavy 

19. Horseshoe, heavy 

20. Glacier, moderate 

21. Ice Lake Trail Jet., heavy 

22. Copper Cr. Trail Jet., moderate 

23. Minam, heavy 

24. Cheval, light 

25. Long, moderate 

26. Steamboat, mode rate 

0 Kilometers 

0 Miles 

Figure 4.--Location of sample campsites and their level of use_ 

4 
Figure 5.--Light-use site number 8, 

located at Wild Sheep Lake. 

Figure 6.--Moderate-use site number 1, 

located at Tombstone Lake. 

Figure 7.--Heavy-use site number 7, 

located at Chimney Lake. 

5 
FIELD METHODS 

To a great extent, study methods were determined by 

the need to establish permanent sampling points. This 

reflected the primary goal of the study--to measure change 

in campsite conditions on permanently located sites over a 

5-year period. The results presented here, relating 

current conditions to amount of use, were an additional 

product of the study. 

Each sample site consisted of both a campsite and a 

similar undisturbed site in the vicinity which could serve 

as a control. In each campsite, 16 linear transects were 

established, radiating from a central point in 16 cardinal 

directions. The distances to the edges of the campsite 

and the first significant amount of vegetation were 

recorded for each transect (fig. 8). The amount of 

vegetation was considered significant when cover 

exceeded 15 percent in a 1.09- by 3.28-ft (0.67-by 1.0(}-m) 

quadrat, oriented perpendicular to and bisected by the 

tape. 

Within the camp area (the polygon enclosed by straight 

lines connecting transect end points), all trees greater than 

55 inches (140 em) tall were recorded. If damaged by 

recreational use, the type of damage was recorded. Seedlings between 6 and 55 inches (15 and 140 em) tall were 

counted within the camp polygons, exclusive of any 

"islands" of undisturbed vegetation (fig. 8). 

Four additional transects were established, originating 

at each center point. The first transect was randomly 

-- Edge of actua I camp a rea 

----Edge of bare area 

-·-Edge of camp area, 

defined by transect end points 

Untrampled 11 lsland 11 

oriented, with each subsequent transect oriented 

perpendicular to the preceding one. Approximately 

15 quadrats, 3.28 by 3.28 ft (1 by 1 m) were located along 

these transects (fig. 9). The exact location of these 

quadrats was taken from a table prepared prior to field 

work, and was designed to maximize the probability that 

all distances from the central point would be sampled with 

equal intensity (that is, the distance between successive 

quadrats on a transect decreased with distance from the 

central point). This assured that (1) the entire disturbance 

gradient, from central point to the undisturbed periphery, 

would be equitably sampled; and (2) there was a chance 

that all parts of the campsite, except the central point, 

would be sampled. 

In each quadrat, the coverage of ·each of the following 

variables was estimated: rock, firepit, tree trunk and root, 

exposed mineral soil, organic litter, and vegetation. The 

cover of each vascular plant species and that of mosses as 

a group were also estimated. Coverages were estimated 

to the nearest percent if under 1 0 percent and in 10 percent 

coverage classes where cover exceeded 10 percent. In 

the latter case, the midpoints of each class were used to 

estimate mean cover on the campsite. 

Soil information was collected at four places on each 

campsite between 3.28 and 6.56 ft (1 and 2 m) from the 

central point (fig. 10). In contrast to the ground-cover 

information, this concentrates the sampling in the most 

highly disturbed parts of the campsite. 

Figure B.--Hypothetical example of transect layout 

for determining camp area and radius and bare area 

and radius. Seedlings were recorded on the camp 

area defined by transect end points, exclusive of 

the untrampled "island;" mature trees were 

recorded on the entire camp area. 

6 
Figure 9.--Coverages of rock, firepit, tree trunk and root, exposed 

mineral soil, organic litter, and vegetation were estimated in 

approximately 15 quadrats on each campsite. 

D Quadrat 

x Soil sample location 

Untrampled ''Island'' 

Figure 10.--Quadrat layout and location of soil 

samples on hypothetical campsite. 

7 
At each of the four locations, duff depth, bulk density, pH, 

and infiltration rates were measured and soil samples 

collected. Duff depth was a measure of the depth of the 

organic litter and fermentation (0) horizons. The 

colorimetric method was used to determine pH in the 

field. Infiltration rates were measured with a doublering infiltrometer. The rate at which the first 0.39 inch 

(1 em) entered the soil was called the instantaneous 

infiltration rate, while the rate for the first 2 inches (5 em) 

was called the saturated rate. Sample points were not 

presoaked. Volumes for bulk density calculations were 

determined by measuring the amount of water required to 

fill a hand-excavated, cellophane-lined hole, 2 inches 

(5 em) deep by about 3.5 inches (9 em) in diameter. The 

excavated soil was removed in plastic bags for weight 

determination (fig. 11 ). Use of the hand-excavation method 

made precise volume measurements difficult, but this 

method was judged to be more accurate than the use of 

soil corers in these rocky soils. As with pH, bulk 

density measurements were taken in the uppermost 

portion of the mineral soil after the organic horizons had 

been removed. 

Finally, each campsite was assigned a condition class 

rating, a visual estimate of campsite condition developed 

by Frissell (1978). 

Figure 11.--lnfiltration rates were measured with a double-ring 

infiltrometer. Soil samples were collected and the volume of the 

excavated hole was determined for use in calculating bulk density. 

8 
Control plots were located in the vicinity in order to get 

some measure of undisturbed conditions. The size of 

controls varied between 980 and 2,164 fF (91 and 201 m2). 

Percent coverage was estimated for rock, tree trunk and 

root, exposed mineral soil, organic litter, vegetation, and 

plant species for the entire control plot. Seedlings were 

counted on a 538-fF (5Q-m 2) circular subplot. Four sets 

of soil measurements and samples, identical to those 

taken on campsites, were taken on control plots. 

DATA ANALYSIS 

Distances to the edges of the campsite and the edges 

of the bare area were averaged to obtain mean radius of 

camp and bare area measures. They were also plotted 

on scaled maps, and a polar planimeter was used to 

determine the camp and bare area. "Islands" of 

undisturbed vegetation intercepted by more than one 

transect were subtracted from the total area. 

A single mean value was calculated for duff depth, bulk 

density, pH, instantaneous infiltration rate, and saturated 

infiltration rate for each campsite and each control. 

Infiltration rates were expressed in centimeters-perminute for both the 1-cm and 5-cm applications. The pH 

values were converted to H+ concentrations, averaged, 

and reconverted to pH values. 

Soil samples were analyzed at the Montana Forest and 

Conservation Experiment Station, Missoula, Mont. Each 

sample was ovendried and weighed to determine bulk 

density. Nitrate content was determined before drying, 

using the Specific lon Analyzer. The four soil samples 

from each campsite were then passed through a 2-mm 

screen and composited. Calcium, potassium, magnesium, 

and sodium concentrations were determined by extraction 

in 1 N ammonium acetate and analysis with the Atomic 

Absorption Spectrophotometer. Phosphate was extracted 

with dilute acid fluoride and its concentration determined 

by molybdenum blue stannous chloride color reaction; 

total nitrogen was determined by using the modified microKjeldahl procedure (Hesse 1972). Texture was analyzed 

by buoyucous hydrometer method and organic matter 

content was determined by combustion at 525° C. 

For statistical analysis, standard parametric tests could 

not be used because the assumption of a normally 

distributed population could not be made and the sample 

size was small. Therefore, nonparametric tests were used 

and the tabular data presented include medians (probably 

the best measure of central tendency), as well as means 

and their 95 percent confidence interval. 

The significance of differences between campsites and 

controls was examined with the Wilcoxon matched-pairs, 

signed-ranks test (Siegel 1956). Those variables that 

differed were examined further in order to see if the 

differences were correlated with difference in amount of 

use. 

The relationship between campsite impact and amount 

of use can be examined in several ways. Most studies have 

compared existing conditions on campsites that receive 

different amounts of use. This approach has the serious 

drawback of assuming that all sites were originally 

identical and, therefore, that differences in the existing 

conditions on I ightly and heavily used campsites reflect 

9 

differences in the amount of change which has occurred, 

rather than differences in original conditions. 

This drawback can be alleviated, to some extent, by 

establishing campsite-control pairs and comparing the 

differences between campsites and controls--an estimate 

of amount of change--on sites which receive different 

amounts of use. The problem with this approach, which 

has only been tried by Frissell and Duncan (1965) and 

Fichtler (1980) is that results will be misleading if control 

sites are not truly similar to original campsite conditions. 

Both approaches have opposing strengths and weaknesses. One uses no information about original conditions 

(control samples), while the other uses so much information that results may be distorted by too much faith in 

control samples. Both approaches have been taken in this 

study in order to profit from the unique perspective each 

provides. 

In this second type of analysis, both absolute and 

relative measures of change are presented. Absolute 

change is simply the difference between the measure on 

the control site and the measure on the campsite. For 

example, if vegetation cover was 10 percent on the controlsite and 1 percent on the campsite, the absolute change 

would be 9 percent. Because absolute change is highly 

dependent on original conditions (in the example above, 

10 percent is the maximum change possible), relative 

values were also calculated. Relative change is the 

absolute change expressed as a percentage of the measure 

on the control site. In the example above, relative change 

measures show that 90 percent of the vegetation has been 

lost. Again, both of these change measur:.es are provided to give as complete an interpretation of the data as 

possible. Negative change values, in both cases, indicate 

higher values on the campsite. 

Change in species composition was measured with the 

following coefficient of floristic dissimilarity: 

FD = 0.5~/P1-P i 

where p1 is the relative cover of a given species on the 

control plot, and p2 is the relative cover of the same species 

on the campsite (Cole 1978). Additional methods of 

species composition analysis are discussed in the results 

section. 

Finally, a summary impact rating was calculated for each 

campsite in a manner similar to that employed by Merriam 

and others (1973). Impact indicators included camp 

area, relative vegetation loss, absolute increase in bare 

ground, floristic dissimilarity, relative seedling loss, 

percent of trees with trunk scars, relative decrease in duff 

depth, and relative decrease in instantaneous infiltration 

rate (table 1 ). For each of these indicators, the range in 

amount of change was divided into three classes with 

approximately the same number of campsites in each 

class. Each campsite was assigned to one of these 

classes and given an impact value of 1 to 3 (low to high 

amount of change) for each indicator. The mean of all 

impact values that apply to each campsite4 determines 

the index of impact or impact rating. 

4 When there were no trees on the camp. the trunk scar 1nd1cator was not 

considered: when there were no seedlings on controls. the seedl 1ng 

1nd1cator was not considered. 
Table 1.··Values used to calculate the impact rating for each campsite 1 

Indicators of impact 

Impact 

value 

Camp 

area 

Relative 

vegetation 

loss 

Absolute 

increase in 

bare ground 

Floristic 

dissimilarity 

Relative 

seeding 

loss 

Trees with 

trunk scars 

Relative 

decrease in 

duff depth 

Relative de· 

crease in in· 

stantaneous 

infiltration rate 

m2 ---------------------------------------------------------------------------------------Percent---------------------------------------------------------------------------------------

<100 < 75 < 10 <50 

2 100-220 75-95 10-40 50-65 

3 >220 > 95 > 40 > 65 

1

The impact rating is the mean impact value for all impact indicators used. 

All correlations used Kendall's tau as a statistic (Siegel 

1956). Kolmogorov-Smirnov tests (Siegel1956) were used 

to compare the amount of change which had occurred on 

heavily used sites located within 200 feet (61 m) of lakeshores to that on heavily used sites more than 200 feet 

(61 m) from lakeshores. 

RESULTS AND DISCUSSION 

How Much Change Has Occurred on the Campsites? 

Campsite area varied between 387 and 6,060 fF (36 and 

563 m2), with the median site being 2,077 fF (193 m2) 

(table 2). The largely barren central core comprised about 

45 percent of a "typical" campsite, although this 

percentage varied between 15 and almost 100 percent. 

Essentially all of the trees growing on those sites had 

been "damaged" by recreationists (fig. 12). Damage to 

many of these trees was relatively minor--lower branches 

had been broken or nails had been driven into the trunks. 

Twenty-seven percent of these trees, however, bore trunk 

scars from chopping. Of these scars, 22 percent were 

larger than 1 fF (0.99 m2 ) and 67 percent were located below 

breast height, conditions under which the probability of 

decay in spruce and true fir is particularly high (Wright 

and Isaac 1956). 

Another 33 percent of the trees on the campsites had 

been cut down. Observations in the field suggested that, 

as a damage estimate, this value should have been even 

higher because more felled trees were found just beyond 

< 76 < 15 < 45 < 20 

76-95 15-45 45-75 20-70 

> 95 > 45 > 75 ' > 70 

the campsite periphery than on the campsite itself. Most of 

these felled trees were less than 2 inches (5 em) in diameter 

at breast height, so the loss of saplings available to 

eventually replace the overstory trees is also more 

dramatic than these figures suggest. 

This frequency of mechanical damage to trees is higher 

than that reported elsewhere. McCool and others ( 1969) 

report that 60 to 65 percent of the sites they studied in 

the Boundary Waters Canoe Area had damaged trees; in 

the Eagle Cap essentially all sites with trees had damage. 

In two Montana backcountry areas, only 68 percent of the 

trees on all campsites had been damaged (Fichtler 

1980). 

Despite this damage to the overstory, there was little 

evidence of recreation-related tree mortality or even loss 

of vigor except where trees had been felled outright. The 

fact that more than six decades of recreational use have 

had little noticeable effect suggests that premature 

mortality may never by a serious problem. Other studies 

have also noted a lack of tree mortality despite extensive 

mechanical damage (for example, James and others 1979) 

except where the tree species is particularly susceptible 

to decay (Hinds 1976) or where severe edaphic limitations 

occur (Settergren and Cole 1970). This has led to the 

conclusion that mature trees are the growth form least 

sensitive to recreational impact (Leeson 1979). It is 

possible, however, that premature windthrow may not 

be recognized as recreation-caused or that disease may 

eventually become a problem. 

Table 2.··General characteristics of the campsites 

Camp Bare Mutilated Trees with Felled Scarred Floristic 

area area trees exposed roots trees trees dissimilarity 1 

Statistic (N = 22) (N = 22) (N = 19) (N = 19) (N = 19) (N = 19) (N = 22) 

---------------------m2·-------------------- ----------------------------Percent-------------------------------------------------------------------------------------

Median 193 87 96 32 28 25 

197 ±57 97±27 91 ± 5 34± 12 33 ± 11 27±9 

1 A measure of the percent change in species composition on the campsite. 

2A visual estimate of impact proposed by Frissell (1978) which varies between 1 (low impact) and 5 (high impact). 

3

1ncludes a 95 percent confidence interval. 

10 

59 

55±8 

Condition 

class2 

(N = 22) 

4.0 

3.7 ± 0.3 
Figure 12.--0ver 90 percent of the mature trees on the sample campsites 

had been scarred, felled, or had limbs cut. 

Of the 19 campsites with trees on the site, 17 had trees 

with exposed roots. On a typical campsite, approximately 

30 percent of the trees had exposed roots. Frissell 

and Duncan (1965) found trees with exposed roots on 

60 percent of the campsites they examined, while James 

and others (1979) found 7 to 14 exposed roots per sample 

tree on their campsites. 

Seedling densities on control sites were almost 10-times 

higher than on campsites (table 3). This amounts to a 92 

percent loss of seedlings on the median campsite, with no 

campsite having more than 50 percent of the seedlings 

found on undisturbed sites. The few seedlings that do 

survive on campsites (four seedlings per site was the 

median) inevitably occur in protected areas behind 

Table 3.·-Ground coverages and seedling densities for campsites and controls and estimates of amount of change 1 

Statistic 

Seedlings 

(N = 22) 

Vegetation 

(N = 22) 

Bare 

ground 

(N =22) 

Litter 

(N = 22) 

Stone 

(N =22) 

Tree trunk 

and root 

(N =22) 

Stems/ha ----------------------------------------------------------------------Percent-------------------------------------------------------------

Campsite 

Median 

Mean2 

Control 

329 

507 ± 236 

Median 2,647 

Mean 5,020 ± 2,362 

Median absolute change 2,266 

Median relative change (percent) 92 

Significance level 3

<0.001 

6 

8±4 

61 

55± 10 

47 

87 

3

<0.001 

31 

33 ± 10 

6±5 

-25 

-1,598 

3

<0.001 

59 2.4 

51± 10 4.6 ± 2.4 1.5 ± 0.6 

27 5.0 

28±7 10.7 ± 5.4 0.8 ± 0.4 

-30 3.0 -0.6 

-116 58 -10 

0.002 0.005 

1

Absolute change is the control value minus the campsite value; relative change is the absolute change divided by the control value. Positive 

values indicate that campsite values are lower than control values; negative values indicate higher campsite values than controls. Significance was tested 

with the Wilcoxon matched-pairs, signed-ranks test. Differences were considered significant if the level of significance was less than 0.05. Nonsignificant differences are left blank. 

2

1ncludes a 95 percent confidence interval. 

3

one-tailed tests were used because the direction of change was predicted prior to testing. 

11 
boulders or in dense clumps of saplings. There was no 

evidence that any of the tree species were particularly 

resistant to trampling. This near-elimination of seedlings 

has been reported wherever campsite seedling densities 

have been studied (Frissell and Duncan 1965; Magill and 

Nord 1963; Brown and others 1977; Fichtler 1980). Along 

with the loss of saplings to felling, this forecasts a future 

lack of trees to replace the overstory trees when they 

eventually die. Continued recruitment of trees will 

probably be one of the major challenges to long-term 

site maintenance. 

Ground-cover changes have also been dramatic. As 

vegetation cover has disappeared, increasing amounts of 

bare mineral soil and organic litter have been exposed. 

A small, but statistically significant, decrease in stone 

cover is also evident. This may result from removal of rocks 

on campsites to make fire rings or to smooth sleeping 

areas, but probably also reflects a tendency for campsites 

to be located on exceptionally stone-free sites. 

In comparison to controls, the median campsite had onetenth the vegetative cover, 30 times as much bare ground, 

and twice the exposed litter cover. Eighty-seven percent 

of the original vegetation had been lost, leaving only 6 

percent scattered about the site. These results are 

comparable to those of Frissell and Duncan (1965) in the 

Boundary Waters Canoe Area, and to Coombs' (1976) 

measures on heavy-use sites in the Idaho Primitive Area. 

Cover loss was much less extreme on developed sites in 

Rhode Island (Brown and others 1977) and Pennsylvania 

(LaPage 1967), where trampling-resistant species, usually 

exotic grasses, maintain some vegetative cover. 

The median floristic dissimilarity between campsites and 

controls, 59 percent, indicates that a pronounced shift in 

species composition of the undergrowth has occurred. 

Inherent variability in species composition between 

undisturbed stands of this vegetation type accounts for 

about 25 percent of this dissimilarity (Cole 1978). 

Differences in excess of 25 percent can be attributed to 

changes resulting from recreational use. Previous 

estimates of floristic dissimilarity on similar campsites 

in the Eagle Cap Wilderness were about 80 percent (Cole 

1981 a), but these campsite measurements were concentrated close to the heavily used central core of the 

site. Apparently, and not unexpectedly, the change in 

species composition on each campsite decreases from 

campsite center to campsite periphery. 

Every species experiences a decrease in cover on the 

campsites, with the exception of three introduced species--

Poa annua (annual bluegrass), Sagina saginoides 

(alpine pearlwort), and Spergularia rubra (red sandspurry), and six natives that are only found in small 

quantities on one or two of the campsites. 5 Therefore, there 

is no widespread "invasion" of species that increase in 

abundance in response to recreational use. This contrasts 

with lower elevation campsites where weedy invaders such 

as Taraxacum officinale (common dandelion) and Poa 

pratensis (Kentucky bluegrass) are usually the most 

abundant species on campsites (Cole 1977). 

Some species increase in relative importance on campsites, however. Table 4 provides two indexes of change in 

importance for the most common vascular plant species in 

the area. The major species that increase in importance on 

campsites are Carex microptera (small-winged sedge), 

12 

Carex rossii (Ross sedge), Juncus parryi (Parry's rush), 

Muhlenbergia filiformis (pullup muhly), and Sibbaldia 

procumbens (creeping sibbaldia), four graminoids, and a 

rhizomatous, mat-forming forb with creeping stems. A 

number of other studies have also found that Carex sp., 

Juncus parryi, and Sibbaldia procumbens are resistant to 

trampling (for example, Landals and Scatter 1973; Holmes 

and Dobson 1976). 

The major species that decrease in importance on 

campsites are Antennaria alpina (alpine pussytoes), 

Festuca viridula (green fescue), Hieracium gracile 

(slender hawkweed), Phyllodoce empetriformis (red 

mountain-heath), Potentilla flabellifolia (fan-leaf 

cinquefoil), Vaccinium scoparium, and Veronica cusickii 

(Cusick's speedwell). The sensitivity of the brittle shrubs 

Phyllodoce and Vaccinium has· been a consistent 

finding (for example, Dale and Weaver 1974; Hartley 

1976), but resu Its for the other species have been 

inconsistent. For example, Hieracium gracille has been 

judged to be resistant by Coombs (1976) and sensitive by 

Schreiner (1974), Hartley (1976), and this study. 

Apparently, the response of many species varies with such 

factors as season, type of impact, associated plants, and, 

perhaps, phenotypic variability within the species. 

The three most prominent understory species on 

controls-- Vaccinium scoparium, Phyllodoce 

empetriformis, and Juncus parryi--undergo pronounced 

shifts in importance on campsites (table 5). The median, 

combined, relative cover of Vaccinium and Phyllodoce 

drops from 39 percent on controls to 6 percent on campsites, while the median, combined, relative cover of Juncus 

and Carex rossii increases from 8 percent on controls to 

28 percent on campsites. All differences are statistically 

significant. 

When the response of major growth forms to camping 

is compared, graminoids increase in importance, while 

shrubs and bryophytes decrease, and forbs are essentially 

unaffected (table 5). Shrubs make up 41 percent of the 

cover on controls, but only 9 percent on the median 

campsite. Median graminoid values increase from 28 

percent on controls to 56 percent on campsites. Similar 

responses have been noted in other subalpine campsite 

impact studies (Cole 1979; Leeson 1979; Weaver and others 

1979). 

As vegetation cover is removed, litter cover values 

increase. This increase, apparent in table 3, is not a real 

increase in litter; more litter is exposed because the overlying vegetation cover has been removed. Failure to 

recognize this has caused confusion about litter response 

to camping in some studies (for example, Coombs 1976). 

Increased litter cover values on campsites indicate that 

vegetation cover is removed more rapidly, exposing the 

underlying litter, than litter is removed, exposing bare 

ground. Nevertheless, litter is being removed, as the 

increases in bare ground indicate. Table 3 shows that on 

the median campsite, litter cover increases about 50 

percent as a result of vegetation destruction, but about 

25 to 30 percent of the litter cover is eroded, exposing 

b3re ground. 

5Appendlx 1 contains frequency and cover data for all spec1es 

encountered on campsites or controls 
Table 4.··Relative importance of the most common vascular plant species 1 on campsites and controls 

Species A2 82 

Antennaria a/pina 0.3 0.9 

Antennaria lanata 2.4 .7 

Carex microptera 1.5 1.5 

Carex rossii 9.0 4.5 

Erigeron peregrinus .6 1.9 

Festuca viridula .2 .. 9 

Hieracium gracile .1 .4 

Juncus parryi 3.2 1.7 

Luzula hitchcockii .8 1.6 

Muhlenbergia filiformis 1.5 3.6 

Phyllodoce empetriformis .5 .4 

Potentilla flabellifolia .5 .5 

Sibbaldia procumbens 1.3 3.5 

Vaccinium scoparium .2 .5 

Veronica cusickii .6 .7 

1

AII species with a mean cover greater than 1 percent or which occur on more than one-third of the control sites. 

2

Column A is the ratio between the number of cases in which relative cover is higher on campsites than controls, and the 

number of cases in which the reverse is true. Column B is the ratio between mean relative cover on campsites and mean relative 

cover on controls. A number greater than 1 indicates that the species increases in relative importance on campsites. 

Table 5.-·Relative cover of growth forms and selected species on campsites and controls 

Growth forms Control sites Campsites 

and (N =21) (N = 21) 

selected species Median Mean Median Mean 

Graminoids 28 27±7 56 55±7 

Shrubs 41 42 ± 10 9 19±8 

Forbs 18 19±5 21 21 ±8 

Bryophytes 10 12±4 5±3 

Carex rossii 2 2±1 8 14 ± 7 

Juncus parryi 6 12 ± 5 20 22±7 

Vaccinium scoparium 30 28±9 5 13 ± 7 

Phyllodoce empetriformis 9 11 ± 4 5±3 

Significance 

level 1 

0.002 

.002 

.005 

.001 

.005 

.005 

.004 

1

Significance was tested with the Wilcoxon matched-pairs, signed-ranks test. Differences were considered significant if the 

significance level was less than 0.05. Nonsignificant differences are left blank. 

13 
This increase in bare ground is much more severe than 

that reported by Young (1978) on developed sites in 

Illinois, or by Frissell and Duncan (1965) and Fichtler 

( 1980) on backcountry sites in Minnesota and Montana, 

respectively. It is comparable to the results of Brown and 

others (1977) for developed sites in Rhode Island and of 

Coombs (1976) for bare soil and erosion pavement on 

heavy-use, backcountry sites in Idaho. 

The loss of organic litter is more evident in the decrease 

in duff depth presented in table 6. The depth of the soil 

organic horizons on campsites was less than one-half what 

it was on controls. On the other hand, the organic matter 

content of the upper A horizon was about 20 percent higher 

on campsites than on controls, suggesting that, although 

some of the surface organic litter pulverized by recreational use is probably removed by erosion, some of it moves 

down into the uppermost mineral horizons where it 

accumulates. Monti and Mackintosh (1979) present 

photomicrographs which clearly show bands of "humus" 

particles which have accumulated in the upper 2.54 to 7.62 

inches (1 to 3 em) of mineral soil on campsites in Ontario. 

About 55 percent of the 0 horizon was lost on these campsites, a figure close to the 51 percent lost on Eagle Cap 

campsites, despite much heavier use in Ontario. Similar 

measures of reduction in duff depth--60 to 65 percent--

have been reported on campsites in the Boundary Waters 

Canoe Area (Frissell and Duncan 1965; McCool and others 

1969). 

Measures of the magnitude and even direction of change 

in soil organic matter content have been less consistent. 

We found a 20 percent increase on campsites. Monti and 

Mackintosh (1979) and Legg and Schneider (1977), 

working in northern forest types in Ontario and Michigan, 

respectively, also report accumulations of organic 

matter in the surface mineral horizons on campsites, but 

they did not compare this to conditions on control sites. 

Young and Gilmore (1976) found a 28 percent increase in 

soil organic matter on forested campsites in Illinois. 

Studies in Colorado, Iowa, and Ontario, however, have 

found decreases in soil organic matter on campsites 

(Dotzenko and others 1967; Dawson and others 1978; 

Rutherford and Scott 1979). At this time, there is no 

apparent explanation for this difference in results, as the 

direction of change is not correlated with vegetation type, 

soil type, climatic regimen, campsite age, amount of use, 

or measurement technique. 

Bulk density increased on campsites, but this increase 

was not as great as expected (15 percent). Bulk densities 

were unusually low, both on campsites and controls, 

reflecting the high organic matter content of the soil and 

the influence of volcanic ash. These characteristics make 

the soil less compactible and prevent the more sizable 

increases of 72 percent, 46 percent, 34 percent, 30 percent, 

23 percent, and 21 percent reported on campsites in Rhode 

Island (Brown and others 1977), Colorado (Dotzenko and 

others 1967), Ontario (Monti and Mackintosh 1979), Iowa 

(Dawson and others 1978). Missouri (Settergren and Cole 

1970), and Michigan (Legg and Schneider 1977), respectively. 

Although the effects of changes in bulk density on 

vegetative growth are highly variable, most studies have 

shown no harmful effects until bulk densities exceed 1.3 

g/cm3 or more (Barton and others 1966; Minore and others 

1969). In fact, in some sandy soils, low levels of compaction 

improve the growth of certain species by increasing the 

water-holding capacity of the soil (Biom 1976). This 

suggests that, particularly on the Eagle Cap campsites 

where bulk densities are universally low, increases in 

bulk density may not be a significant impact. Other 

manifestations of compaction, such as decreased infiltration rates or loss of microsites suitable for seed germination (Harper and others 1965), may be more significant. 

Table 6.-·Soil conditions on campsites and controls and estimates of amount of change 1 

Ins tan· Satu· 

taneous rated In· 

Duff lnfiltra· filtration Total Organic Bulk 

depth pH tion rate rate N03 K Mg Ca Na P04 N matter density 

Statistic (N=22) (N=20) (N =20) (N =22) (N =20) (N=20) (N=20) (N=20) (N=20) (N=20) (N=20) (N=20) (N=20) 

em ........... em/min-......... .. ....................................................... parts per million ......................................................... Percent glcm 3 

Campsite 

Median 0.25 5.48 0.33 0.16 7.6 195 61 528 53 14 3,193 18 0.95 

Mean2 0.32 ± 0.18 5.44±0.16 0.38±0.10 0.16±0.04 7.9 ± 2.5 211 ±39 80±33 666 ± 222 55±5 20±9 3,493 ± 780 19±4 0.96 ±0.09 

Control 

Median 0.53 5.13 0.59 0.25 3.6 167 39 287 45 11 2,342 15 0.88 

Mean 0.74 ± 0.30 5.13 ± 0.09 0.66 ± 0.17 0.26 ±0.05 7.4 ± 2.9 183 ± 37 42±8 3n2 ± 89 47±3 21 ±9 2,868± 626 15±2 0.88± 0.08 

Median 

Absolute 

Change 0.30 -0.50 0.19 0.09 -4.1 -40 -23 -300 -6 0.8 -165 -2 -0.11 

Median 

Relative 

change (percent) 51 -9 29 33 -68 -28 -107 -101 -13 -5 -20 -15 

Significance 3<.001 .003 3.003 3<.001 .001 .002 .014 .027 3.047 

1 Absolute change is the control value minus the campsite value; relative change is the absolute change divided by the control value. Positive values indicate that campsite values are 

lower than control values; negative values indicate higher campsite values than controls. Significance was tested with the Wilcoxon matched-pairs, signed-ranks test. Differences were considered significant if the level of significance was less than 0.05. Nonsignificant differences are left blank. 

1nc~udes a 95 percent confidence interval. 

3one-tailed test. 

14 
The decreases in infiltration rates on Eagle Cap campsites, while statistically significant, are also much less 

pronounced than decreases found elsewhere. The rate 

at which the first 0.39 inch (1 em) of water percolates into 

the soil is 28 percent slower on campsites than on controls; 

the decrease on campsites when 2 inches (5 em) of water 

were applied was about the same--33 percent. In contrast, 

other studies have found infiltration rates on controls to 

be 20 to 60 times higher than on campsites (Brown and 

others 1977; James and others 1979; Monti and Mackintosh 

1979). 

Most of this difference in magnitude of change is a 

result of extremely low infiltration rates on Eagle Cap 

controls. Infiltration rates on the campsites are 

comparable to those on campsites in other studies; rates on 

controls are an order of magnitude lower. Soils were 

notably hydrophobic and were not presoaked. Hydrophobicity, which can cause dramatic reductions in infiltration rates, is particularly pronounced in highly organic 

and sandy soils, like those in this study (Singer and 

Ugolini 1976). Studies have also found soils under 

ericaceous shrubs and conifers to be particularly waterrepellant (Richardson and Hole 1978). 

Finally, several statistically significant changes in soil 

chemistry were found. From a median value of 5.13 on 

controls, pH increased to 5.48 on campsites. Concentrations of Mg, Ca. and Na were also significantly higher on 

campsites; Mg increased 107 percent, and Ca and Na 

increased 101 percent and 13 percent, respectively. 

Concentrations of N03 , K, and tot~ I N increased ~n ?~mpsites, but the results were so vanable that a s1gn1f1cant 

difference could not be established. Phosphate content, 

like particle-size distribution, 6 did not differ. These 

results contrast somewhat with those of Young and 

Gilmore (1976). They found similar increases inCa (116 

percent) and Na (57 percent) on campsites, in addition to 

increases in P (50 percent) and N (26 percent), and no 

change in Mg, the nutrient which increased the most on 

the Eagle Cap campsites. Rutherford and Scott (1979) 

found no change in Mg, K, or P04, and a decrease in N03. 

Obviously, the effects of camping on soil chemistry are 

highly variable, depending upon the extent to which campfire ashes are scattered about the site; the nutrient inputs 

in excess food, soap, and so forth; the degree to which 

leaching is reduced by decreased infiltration rates (Young 

and Gilmore 1976); and the innate character of the 

undisturbed soil. 

It is doubtful, however, that any of these changes are 

significant in an ecological sense. For example, in a 

Montana study which included Abies lasiocarpa-Pinus 

contorta-Carex geyeri- Vaccinium scoparium (subalpine 

fir-lodgepole pine-elk sedge-grouse whortleberry) forests, 

seasonal variations in soil pH and Na content were greater 

than the differences between campsites and controls found 

in this study (Weaver and Forcella 1979). Although 

changes in Mg and Ca concentrations on campsites were 

greater than their seasonal variability, the differences 

were not sufficiently dramatic to suggest any basic 

ecological change. 

6 Data are not presented because no differences between camps1te and 

control were noted 

15 

It is interesting to note that those ions which increased 

the most on the Eagle Cap campsites are highly mobile 

ions, particularly susceptible to leaching. Their presence in 

high concentrations on campsites supports the hypothesis 

of Young and Gilmore (1976) that campsite increases are a 

result of reduced leaching. 

To What Extent Do Impacts Vary with Differences 

in Amount of Use? 

Despite these sizable differences between campsites and 

controls, the amount of change that has occurred on 

campsites is extremely variable. This is reflected in the 

large confidence intervals around the means in tables 2, 

3, 5, and 6. It has often been assumed that most of this 

variability in campsite conditions and impacts can be 

attributed to differences in the amount of use the site 

receives. 1 (Cole 1981 b) have suggested that environmental differences usually contribute more to variability 

than use differences. In this study, environmental 

variability was reduced by only examining campsites in 

Abies Jasiocarpa/Vaccinium scoparium forests, close to 

lakes, and between elevations of 7,050 and 7,800 ft (2 150 

and 2 400 m). This allowed a clearer view of the relationship 

between amount of use and campsite impact. 

The relationship between amount of use and impact, for 

parameters which exhibit significant differences between 

campsites and controls, are presented in tables 7, 8, and 9. 

Amount of use is compared to existing site conditions 

(table 7), the absolute amount of change which has 

occurred on the site (table 8), and the relative amount of 

change which has occurred on the site (table 9). 

From these tables, there is no significant correlation 

between the amount of use a site receives and the following 

variables: camp area; mutilated, felled, or scarred trees; 

litter cover; soil pH; instantaneous or saturated infiltration rates; Mg, Ca. or Na concentrations; soil organic 

matter; or bulk density. 

Although light-use sites are generally smaller than 

moderate- and heavy-use sites (table 7), campsite area 

is highly variable and there is substantial overlap in size 

between use classes. For example, the low-use site at 

Hidden Lake is 2,906 fF (270 m2), while a heavy-use 

site at Minam Lake is only 850 fF (79m 2 ). This variability 

explains the nonsignificant Kendall correlation coefficient 

and also the nonsignificant Kolmogorov-Smirnov contrast 

between light- and moderate- use sites, despite the 

difference in median and mean values. With a larger 

sample size, it would probably have been possible to 

conclude that light-use sites are generally smaller than 

more heavily used sites (significance level was 0.064). 

There is little difference in the size of moderate- and 

heavy-use sites, however. Most increases in campsite 

size can probably be attributed to occasional use by 

abnormally large parties, or parties with packstock, a 

process largely independent of frequency of use by more 

typical, small, backpacking parties. 

Tree mutilations also appear to increase in abundance 

with increasing use, but, again, differences are dwarfed by 

variability. Differences in the frequency of felled and 
scarred trees are not related in any consistent manner to 

the amount of use a site receives. This is not surprising 

as most tree damage can probably be ascribed to a few 

atypically destructive groups, again making the frequency 

of use by undestructive parties irrelevant. Fichtler 

(1980) also found no relationship between use and tree 

InJury. James and others (1979), however, did find an 

increase in the number of trunk scars per stem from 1.9 

on recently built, light-use sites to 4.3 on the older, heavyuse sites. This damage, which is cumulative, is probably 

more strongly related to campsite age than to use 

frequency. 

Litter cover, as noted previously, is dependent on 

changes in vegetation cover and bare ground. Consequently, interpretation of these values is difficult. 

Coombs (1976) and Fichtler (1980) reported no difference 

in litter cover between light- and heavy-use sites, but they 

failed to note that vegetation loss causes an apparent, but 

not a real, increase in litter values. Thus, their results, 

similar to these in showing no significant differences 

between use levels, probably disguise a real loss in litter 

cover with increasing use, coincident with an increase in 

bare ground, which will be discussed. Legg and 

Schneider (1977) reported a significant decrease in litter 

cover on more heavily used sites, and Young (1978) 

reported a reduction in litter with increased use, although 

differences were not statistically significant. 

Soil pH generally increases with increasing use. A large 

sample size might have allowed a statistically significant 

relationship to be established, but, again, differences 

between use levels are minor in comparison to site-to-site 

variability (table 7). The same conclusion can be drawn 

from measures of the amount of change in pH on the campsites (tables 8 and 9). Young and Gilmore (1976) found that 

the pH on sites used 34 to 66 d'!YS per year (6.1) was 

significantly higher than the pH on sites used 0 to 33 days 

per year (5.7), but that a further increase in use caused 

no further change. These increases, even if they can be 

attributed to increased use of the campsites, are so 

slight that they are not ecologically meaningful. 

Table ?.··Relationship between campsite conditions and the amount of use the site receives 1 

Light-use Moderate-use Heavy-use 

sites sites sites 

(N=6) (N=6) (N =10) Kendall 

Impact parameter Median Mean Median Mean Median Mean tau 

Camp area (m2

) 48 109 ± 99 224 275 ± 196 205 204±51 

Bare area (m2

) 19 51± 53 122 112 ± 66 93 116 ± 40 0.30 

Mutilated trees (percent) 74 60±49 85 73±40 97 93±7 

Trees with exposed roots (percent) 3 7±8 33 34±26 39 39±22 .41 

Felled trees (percent) 43 41 ±40 12 21 ±26 34 34± 12 

Scarred trees (percent) 3 13± 17 37 36±22 11 21 ± 26 

Floristic dissimilarity (percent) 31 42± 18 60 59±25 64 61 ± 11 .33 

Seedlings (number/ha) 174 314 ± 366 299 404 ± 352 335 686 ± 488 

Vegetation cover (percent) 9 12 ± 11 6 10± 12 4 5±2 ·.41 

Bare ground (percent) 14 30±28 20 26 ± 19 35 40± 16 

Litter (percent) 40 50±28 62 56±25 51 49 ± 17 

Duff depth (em) 0.15 0.22 ± 0.18 0.45 0.67 ± 0.72 0.15 0.18 ± 0.09 ·.35 

pH 5.25 5.32 ± 0.41 5.25 5.37 ± 0.43 5.55 5.58 ± 0.16 

Instantaneous infi It ration 

rate (em/min) 0.54 0.60 ± 0.19 0.19 0.28 ± 0.22 0.28 0.32 ± 0.13 

Saturated infiltration 

rate (em/min) 0.23 0.24 ± 0.17 0.12 0.15 ± 0.07 0.14 0.13 ± 0.04 

Mg (p/m) 34 50±26 67 132 ± 237 61 77±26 

Ca (p/m) 280 425 ± 265 755 1,070 ± 1,345 528 650± 263 

Na (p/m) 54 52± 10 53 62± 16 51 55±8 

Organic matter (percent) 12 18 ± 11 14 17 ± 13 18 20±5 

Bulk density (g/cm3

) 0.95 1.04 ± 0.29 0.90 0.90 ± 0.19 0.95 0.94 ± 0.11 

Impact rating 1.5 1.6±0.4 2.0 2.0 ± 0.4 2.2 2.1 ± 0.2 .41 

1Significance level was 0.05. Nonsignificant relationships are left blank. 

16 
Table a.--Relationship between the absolute amount of change which has occurred on a campsite and the amount of use the 

site receives 1 

Light-use Moderate-use Heavy-use 

sites sites sites 

(N=6) (N=6) (N =10) Kendall 

Impact parameter Median Mean Median Mean Median Mean tau 

Seedlings (number/ha) 1 '113 1,245 ± 667 1,825 3,742±3,241 3,727 6,936 ± 5,210 0.57 

Vegetation cover (percent) 37 38 ± 15 30 40±34 60 56± 15 .29 

Bare ground (percent) ·5 -15 ± 26 -26 -24 ± 19 -32 -37 ± 17 -.34 

Litter (percent) -26 -22±24 -26 -23± 30 -35 -25 ± 20 

Duff depth (em) 0.06 0.13 ± 0.26 0.15 0.58 ± 1.21 0.35 0.49 ± 0.20 .40 

pH -0.15 -0.15 ± 0.39 -0.25 -0.27 ± 0.40 -0.60 -0.36.± 0.24 

Instantaneous infiltration 

rate (em/min)· 0.07 0.21 ± 0.47 0.46 0.41 ±0.37 0.05 0.20± 0.23 

Saturated infiltration 

rate (em/min) 0.01 0.03 ± 0.12 0.12 0.16 ± 0.18 0.09 0.08 ± 0.06 

Mg (p/m) -18 -19 ± 22 -28 -86 ± 136 -35 -30 ± 32 

Ca (p/m) -216 -221 ± 236 ·483 -677 ± 790 -300 -206 ± 176 

Na (p/m) -8 -4± 11 -15 -19± 16 -5 -6± 10 

Organic matter (percent) -5 -5±6 -4 0±6 -2 -5±5 

Bulk density (g/cm3

) -0.13 -0.09 ± 0.15 -0.08 -0.05±0.15 -0.14 -0.09±0.14 

1

The absolute amount of change is the difference between conditions on the campsite and control. A positive change represents a decrease in that 

measure on the campsite. Significance level was 0.05. Nonsignificant relationships are left blank. 

Table 9.··Relationship between the relative amount of change which has occurred on a campsite and the amount of use the site receives 1 

Light-use Moderate-use Heavy-use 

sites sites sites 

(N=6) (N=6) (N =10) Kendall 

Impact parameter Median Mean Median Mean Median Mean tau 

Seedlings (percent) 73 82 ± 17 92 90± 11 89 86± 11 

Vegetation cover (percent) 71 78± 17 71 70±30 94 91 ±6 0.29 

Bare ground (percent) -529 -504 ± 638 -1,595 -2,110±1,967 -3,293 -3,136±1,726 -.43 

Litter (percent) -118 -91 ± 115 ·49 -233 ± 461 -277 -240 ± 207 

Duff depth (percent) 3 2± 109 21 34±52 68 72± 12 .36 

pH (percent) -3 -3±8 -5 -5±8 -11 -7±5 

Instantaneous infiltration 

rate (percent) 8 40 ± 147 57 59±20 12 12±53 

Saturated infiltration 

rate (percent) -2 0±39 39 43±22 42 30±30 

Mg (percent) -41 -67 ± 78 -109 -158 ± 213 -108 -78 ±50 

Ca (percent) -105 -99±97 -160 -178 ± 176 -30 -69±63 

Na (percent) -25 -11 ±23 -33 -45 ± 43 -10 -14±21 

Organic matter (percent) -19 -43±61 -26 2±32 -20 -35 ± 35 

Bulk density (percent) -16 -11 ± 14 -11 -8± 17 -16 -13 ± 16 

1

The relative amount of change is the difference between campsite and control conditions expressed as a percentage of control conditions (that is, 

change as a percentage of original conditions). A positive change represents a decrease in that measure on the campsite. Significance level was 0.05. Nonsignificant relationships are left blank. 

17 

,: 
Differences in the amount of change in other soil 

properties are even more erratic and variable. For example, 

instantaneous infiltration rates are reduced, on the 

average, 40 percent on light-use sites, 59 percent on 

moderate-use sites, and 12 percent on heavy-use sites; 

standard deviations are usually greater than the differences 

between use categories (table 9). The lack of relationship 

between amount of use and infiltration rates, Mg 

concentrations, and soil organic matter supports earlier 

studies. James and others (1979) found mean infiltration 

rates of 0.27 em/min on recently built, light-use sites, 

and 0.29 em/min on older, heavy-use sites. As reduced 

infiltration rates are probably one of the more detrimental 

consequences of soil compaction, these findings--that 

rates are reduced as much on light-use sites as on heavyuse sites--seem very important. 

Young and Gilmore (1976) found similar Mg concentrations and organic matter content on campsites receiving 

different amounts of use. Organic matter content on 

their sites was 3 to 4 percent, in contrast to 17 to 20 

percent on Eagle Cap campsites, suggesting that the 

lack of relationship between use and organic matter 

content applies to a broad range of soil types. 

The lack of relationship between use and bulk density, 

Ca, and Na concentrations is inconsistent with earlier 

studies. Young and Gilmore (1976) report significant 

differences inCa content between light- and moderate-use 

sites; concentrations on light- and heavy-use sites, however, were not significantly different, and differences 

between soil types were more pronounced than differences 

between use categories. They also report significant 

differences in Na content between light- and heavy-use 

sites, but differences between light-and moderate-use 

sites or moderate- and heavy-use sites were not significant. 

Apparently, the relationship between soil chemistry 

change and amount of recreational use can be highly 

variable. The differences involved, however, appear to 

almost always be so slight that differences in availability 

of nutrients to plants should be negligible. This makes the 

question of statistical significance moot. 

The lack of relationship between amount of use and bulk 

density is more difficult to dismiss, as increased bulk 

density is commonly considered to be an ecologically 

significant campsite impact, and both Dotzenko and 

others (1967) and Legg and Schneider (1977) report 

increases in bulk density associated with increased 

use. Perhaps our lack of relationship is a result of measurement error with the hand-excavation technique, or 

perhaps the relative noncompactibility of the Eagle 

Cap soils makes differences in amount of use less 

important. Both Dotzenko and others (1967) and Legg 

and Schneider (1977) found more pronounced differences 

between controls and their light-use sites than between 

light- and heavy-use sites. Increases in soil penetration 

resistance on campsites, another measure of compaction, 

were not correlated with amount of use in Fichtler's (1980) 

study. 

For the remaining parameters, there is some evidence 

that impact may be related to amount of use. These 

parameters will be analyzed in more detail. 

SEEDLINGS 

Seedling densities are actually higher on heavy-use sites 

than on moderate- or light-use sites (table 7). This would 

suggest that impact has been greater on light-use sites. 

18 

An opposing interpretation emerges when absolute 

seedling loss is examined; the difference between the 

density of seedlings on controls and campsites increases 

from light- to heavy-use sites (table 8). Relative seedling 

loss is relatively constant across the use categories. 

In order to facilitate interpretation, these results have 

been graphically portrayed in figure 13. Seedling densities 

on controls are extremely variable, but always an order of 

magnitude greater than the less variable campsite densities 

(fig. 13a). The great variability in seedling densities on 

control sites makes comparisons of absolute loss (fig. 13b) 

misleading and favors the use of relative loss (fig. 13c) 

as a measure of impact. Clearly, seedlings are almost 

completely eliminated on all campsites, regardless of the 

amount of use they receive. Being highly susceptible to 

trampling, any consistent use is sufficient to kill most of 

the seedlings. The number of seedlings surviving on a 

campsite is probably more a function of the number of 

protected suitable germination sites than the amount of 

use the site receives. Fichtler (1980) also found no 

difference in relative seedling loss between light- and 

heavy-use sites. 

VEGETATION COVER 

In comparison to more lightly used campsites, heavy-use 

sites have less vegetation (table 7), and the amount of 

change, whether expressed in absolute values (table 8) or 

relative values (table 9), has been greater. As shown in 

figure 14, however, differences between use levels are 

minor in comparison to the differences between campsites 

and controls. The median cover on the light-use sites 

is 9 percent; 71 percent of the original cover has been 

lost. The median cover on heavy-use sites is 4 percent, a 

94-percent loss. In this case, there is a statistically 

significant increase in vegetation impact associated with 

increased use, but the differences are not pronounced. 

These results are similar to those of Frissell and Duncan 

(1965), who found 12-percent vegetation cover on light-use 

sites; 81 percent of the original cover had been lost. Heavyuse sites retained a 5-percent cover, a 91 percent loss. In 

their case, the difference in existing cover on campsites 

was statistically significant, but the difference in amount 

of change was not. Therefore, at these use levels (higher 

than those found in the Eagle Cap), in the northern 

Minnesota environment, differences in amount of 

vegetation change were not related to amount of use. 

Similarly, Fichtler (1980) found no difference in relative 

cover loss between light- and heavy-use sites in Montana, 

Young (1978) found no relationship between vegetation 

cover and amount of use on Illinois campsites, and 

LaPage (1967) found no relationship between use and 

change in cover after campsites in Pennsylvania were more 

than 1 year old. 

The only study to show any sizable difference in cover 

between light- and heavy-use sites was Coombs' (1976) 

study in the Idaho Primitive Area, where use was extremely 

low. She found about 30 percent cover on light-use 

sites (a relative loss of 30 percent) and 8 percent on heavyuse sites (a relative loss of 81 percent). Apparently, 

vegetation change is considerably less pronounced at 

very low use levels, but even a few nights of use per year 

in the Eagle Cap appears to be enough to eliminate most of 

the vegetation. 
(a) 

7500 

<( 5000 

jt:::~an :::r::: 

C) 

z 

___J 

0 

LL.J 

<( 12, 000 

2:: 

0 

~ 

t/) 

t/) 

0 

___J 

C) 

z 

___J 

0 

LL.J 

LL.J 

t/) 

LL.J 

1-

:=:l 

___J 

0 

t/) 

en 

<( 

8000 

4000 

(b) 

LL.J 

t/) 2500 

L M H 

USE 

C L M H 

USE 

~ 

t/) 

t/) 

0 

___J 

C) 

z 

___J 

0 

LL.J 

LL.J 

t/) 

LL.J 

> 

1-

::s 

LL.J 

0:::: 

Figure 13.--Seedling loss in relation to 

amount of use. Median, mean, and two 

standard deviations for: (a) seedlings 

per hectare on controls, light-, 

moderate-, and heavy-use campsites; 

(b) the absolute reduction in seedling 

density that has occurred on light-, 

moderate-, and heavy-use campsites; 

and (c) the relative reduction in seedling 

density that has occurred on light-, 

moderate-, and heavy-use campsites. 

The medians in each use category have 

been connected by a line. 

(C) 

L M H 

USE 

Species diversity does not vary subs~antially with 

differences in amount of use. The median species richness--the number of species per 161 fF (15m 2)-- was 12, 

1 0.5, and 11.5, on light-, moderate-, and heavy-use sites, 

respectively. The reciprocal of Simpson's index, a measure 

of species heterogeneity which is most sensitive to 

changes in dominant species (Peet 1974), was 4.76, 4.37, 

and 4.48, on light-, moderate-, and heavy-use sites, 

respectively. Young (1978) reported a decrease in species 

19 

~ 

t/) 

t/) 

0 

___J 

z 

0 

1-

;:: 

LL.J 

C) 

LL.J 

> 

(b) 

90 

75 

~ 

0:::: 

LL.J 

> 50 

0 

u 

z 

0 

1-

<( 

1- 25 LL.J 

C) 

LL.J 

> 

0 

L M H 

USE 

(a) 

CLMH 

USE 

t t mean 1 median 

~ 

t/) 

t/) 

0 

___J 

z 

0 

1-

~ C) 

LL.J 

> 

LL.J 

> 

1-

::s 

LL.J 

0:::: 

Figure 14.--Loss of vegetation cover in 

relation to amount of use. Median, 

mean, and two standard deviations for: 

(a) vegetation cover on controls, light-, 

moderate-, and heavy-use campsites; 

(b) absolute reduction in vegetation 

cover on light-, moderate-, and heavyuse campsites; and (c) relative reduction 

in vegetation cover on light-, moderate-, 

and heavy-use campsites. The medians 

in each use category have been 

connected by a line. 

L M H 

USE 

richness at high-use levels, but the short-use season at 

Eagle Cap precludes such heavy use. At the lower use 

levels typical of high-elevation wilderness areas, species 

diversity does not appear to be highly influenced by 

amount of use. In fact, Coombs (1976) found more 

species on light-use sites than on controls, a finding that 

supports the observation that species diversity increases at 

low levels of trampling stress and decreases at high levels 

of stress (Slatter 1978). 
Change in species composition, reflected in the index 

of floristic dissimilarity, does appear to increase with 

increasing use, however, from a median value of 31 percent 

on light-use sites to 64 percent on heavy-use sites (table 

7). This suggests that, although heavy-use sites retain as 

many species and almost as much cover as light-use sites, 

heavy-use sites experience a more pronounced shift in 

species compostion. This contrasts with the results of 

Fichtler (1980), who found no relationship between floristic 

dissimilarity and amount of use. 

Although species composition has been more highly 

altered on heavy-use campsites, there are no significant 

differences in the relative importance of growth forms or 

major species associated with differences in amount of 

use (table 10). James and others (1979) also found no 

relationship between use intensity and understory species 

composition on campsites in coniferous forests, despite 

pronounced shifts in species composition on campsites. 

Apparently, species compositional changes may become 

more pronounced as use intensity increases, but so many 

other factors influence the surviving populations that the 

importance of individual species and growth forms does 

not vary consistently in relation to amount of use. 

The more heavily used sites also have a larger central 

core devoid of vegetation. This bare area increases from 

a median value of 205 fF (19 m2) on light-use sites to 

1,313 fF (122 m2) and 1,001 fF (93 m2) on moderate- and 

heavy-use sites, respectively (table 7). The proportion of 

a site that is denuded, however, is similar on light-, 

moderate-, and heavy-use sites. The barren central core is 

40 percent of the area of the median light-use campsite and 

45 percent of the heavy-use campsite area. 

This finding contrasts with the results of Moorhead and 

Schreiner (1979). Working in Olympic National Park, they 

found no consistent relationship between a similar 

measure of bare area and amount of use, despite significant 

differences in bare area between different vegetation types. 

This is one case where it has been clearly shown that 

environmental differences influence the amount of impact 

more highly than differences in amount of use. 

BARE GROUND 

Although median bare ground increases from light- to 

heavy-use sites, these differences are not statistically 

significant (table 7). When campsites and controls are 

compared to give an estimate of amount of change, 

differences are significant (tables 8 and 9). The median 

light-use site has 5 percent more bare soil exposed than 

its associated control (absolute change); this represents 

a 529 percent increase (relative change). On moderate-use 

sites, 26 percent more bare soil is exposed, a 1 ,595-percent 

increase; and on heavy-use sites, these measures of 

change increase to 32 percent· and 3,292 percent, 

respectively (tables 8 and 9). Graphically portrayed in 

figure 15, this suggests that the increase in bare ground 

which occurs on a campsite is controlled to a significant 

extent by the amount of use the site receives. 

Similar results have been found by Young (1978) on 

campsites in Illinois. He found that bare ground increased 

from negligible amounts on controls to 30 percent on 

light-use sites (0 to 33 days per year) and 56 percent on 

moderate-use sites (33 to 66 days per year), but as use 

exceeded 66 days per year, no significant increase in bare 

ground occurred. Coombs (1976) found that bare ground 

and erosion pavement increased from 2 percent on 

controls to 15 percent on light-use sites and 26 percent on 

heavy-use sites in the Idaho Primitive Area. Fichtler 

(1980) found that bare ground increased sevenfold on 

light-use sites and seventeenfold on heavy-use sites. This 

was the only impact parameter that increased significantly 

with increased use. These results suggest strongly that 

heavy-use sites experience significantly greater increases 

in bare ground exposure than light-use sites. 

Table 10.--Relative cover of growth forms and selected species in relation to amount of use 

Growth forms 

and 

selected species 

Light-use 

sites 

(N =6) 

Median Mean 

Moderate-use 

sites 

(N =6) 

Median Mean 

Heavy-use 

sites 

(N = 10) 

Median Mean 

-------------------------------------------------------------------Percent-------------------------------------------------------------------

Graminoids 66 65± 18 53 51± 15 52 51± 8 

Shrubs 17 16 ± 11 9 16 ± 15 6 21 ± 14 

Forbs 5 13 ± 12 35 29± 21 17 21 ± 12 

Bryophytes 0.3 6± 10 3±3 2 6±5 

Carex rossii 5 5±3 9 20±20 9 15±9 

Juncus parryi 20 29 ± 17 12 14 ±8 27 24 ± 10 

Vaccinium scoparium 3 8± 10 6 14 ± 15 6 15 ± 12 

Phyllodoce empetriformis 2 6±5 0.5 1 ± 1 0.3 6±7 

1

None of the relationships were significant at the 0.05 level. 

20 

Kendall 

tau1 
(a) 

60 

~ 

t. t mean 0 40 

z r median => 

0 

0:::: 

<..:) 

LLJ 

0:::: 20 <( 

C!:l 

0 

C L M H 

USE 

(b) 

~ 

LLJ 

60 ~ 4500 (./) LLJ 

~ (./) 

0:::: ~ u 0:::: 

z u 

40 z 0 3000 

z 0 

=> z 

0 => 0:::: 0 <..:) 0:::: 

LLJ <..:) 

0:::: 20 LLJ 

<( 0:::: 1500 ,:!) <( 

LI..J C!:l 

I- LI..J 

=> > ___..J 

0 I- (./) 0 ::s ro 

<( L M H LLJ 

0:::: 

USE 

Figure 15.--lncrease in bare ground in relation to amount of use. Median, mean, and 

two standard deviations for: (a) bare ground 

cover on controls, light-, moderate-, and 

heavy-use campsites; (b) absolute increase 

in bare ground cover on light-, moderate-, 

and heavy-use campsites; and (c) relative increase in bare ground cover on light-, 

moderate-, and heavy-use campsites. The 

medians in each use category have been 

connected by a line. 

DUFF DEPTH 

(c) 

L M H 

USE 

Table 7 shows a statistically significant decrease in duff 

depth associated with increased use, although light-use 

sites actually have thinner organic horizons than 

moderate-use sites. Measures of reduction in duff depth, 

whether absolute (table 8) or relative (table 9) show sizable 

increases in impact associated with increased use. All of 

these measures indicate that removal of organic horizons 

increases as use intensity increases, despite highly variable 

campsite measurements (fig. 16). The median relative loss 

21 

(a) 

1.5 

2: 

f. t mean 

u 1.0 I r median I0.... 

LI..J 

0 

w.... 

(./) 

(./) 

0 

___..J 

I 

1--

0.... 

LLJ 

0 

w.... 

w.... 

=> 

0 

LLJ 

I-

=> 

___..J 

0 

(./) 

C!:l 

<( 

(b) 

w.... 

=> 0. 5 0 

L M H 

USE 

C L M H 

USE 

~ 

(./) 

(./) 

0 

___..J 

I 

1--

0.... 

LI..J 

0 

w.... 

w.... 

=> 

0 

LLJ 

> 

1--

::s 

I.L.J 

~ 

Figure 16.--Decrease in duff depth in relation to amount of use. Median, mean, and 

two standard deviations for: (a) duff depth 

on controls, light-, moderate-, and heavyuse campsites; (b) absolute reduction in 

duff depth on light-, moderate-, and heavyuse campsites; and (c) relative reduction in 

duff depth on light-, moderate-, and heavyuse campsites. The medians in each use 

category have been connected by a line. 

(C) 

100 

50 

L M H 

USE 

of duff increases from 3 percent on light-use sites to 21 

percent and 68 percent on moderate- and heavy-use sites, 

respectively. James and others (1979) found no relationship between use intensity and duff depth, despite 

pronounced reductions on campsites in general. They did 

not attempt to pair campsites and controls, however; 

so site-to-site variability may have disguised any relationship. A second paper on the same study area (Monti and 

Mackintosh 1979) showed more pronounced reductions in 

duff depth on high-use sites than on medium- or low-use 

sites. 
TREE ROOT EXPOSURE 

The percentage of trees with exposed roots is also 

significantly lower on light-use sites--3 percent compared 

to median values of 33 percent and 39 percent on 

moderate- and heavy-use sites (table 7). Along with the 

relatively small decrease in duff depth on light-use sites, 

this suggests that loss of the surface horizons usually 

does not occur until campsites are used more than about 

five times per year. Conditions are highly variable, 

however; some I ight-use campsites have numerous trees 

with exposed roots and have lost most of their organic 

horizons. James and others (1979) found that the mean 

number of exposed roots within 3.28 ft (1 m) of each 

sample tree increased from 7.1 on recently built, light-use 

sites to 13.8 on older, heavy-use sites. Fichtler (1980), 

however, found no relationship between use and linear feet 

of exposed roots. 

IMPACT RATING 

The overall summary measure of impact, which could 

vary between 1 and 3, had median values of 1.5, 2.0, and 

2.2 for I ig ht-, moderate-, and heavy-use sites, respectively 

(table 7). This general increase in impact in response to 

increased use is statistically significant; however, there 

is a considerable amount of overlap between use classes. 

For example, 90 percent of the heavy-use sites have 

ratings as low or lower than the rating of the most highly 

impacted low-use site. In other words, heavy-use sites 

are usually more highly impacted than light-use sites, but 

differences are slight, and light-use sites can be more 

highly impacted than heavy-use sites. Moreover, 

differences between light- and moderate-use sites are 

much more pronounced than differences between 

moderate- and heavy-use sites. 

How Much Change Occurs in Other 

Environmental Situations? 

It has been suggested that campsite impacts could be 

reduced by locating campsites on durable sites (Cole 

1981 b). Trails illustrate the importance of location where 

poorly located trail segments are badly eroded, while 

adjacent segments, receiving the same amount of use, are 

often in good shape. 

Experimental trampling studies have found that 

trampling impact usually varies more between vegetation types than between use levels. For example, in a 

study at Waterton Lakes National Park, 800 tramples 

reduced the vegetation of a lodgepole pine stand to 1.1 

22 

percent of its original cover. A similar number of tramples 

in a prairie grassland only reduced cover to 22.1 percent. 

To maintain this percentage of original cover in the lodgepole stands would require a reduction in the number of 

tramples to 40 (Nagy and Scotter 1974). In other words, 

shifting the trampling from lodgepole to grassland sites 

would accomplish as much, in terms of maintaining 

original cover, as a twentyfold reduction in use of the 

lodgepole sites. Moorhead and Schreiner (1979) arrived 

at similar conclusions in a study of the bare area on 

campsites in Olympic National Park. 

In order to examine the effects of differences in 

environment, campsite data are presented for four 

additional sites not located close to subalpine lakes 

(table 11 ). Two are located in timberline meadows close 

to 8,200 ft (2 500 m) in elevation.· Campsite 15 at 

Pocket Lake is a light-use site, while campsite 20 at 

Glacier Lake is probably a moderate-use site. The two 

other campsites are located in forested valley bottoms 

below 6,500 ft (2 000 m). Campsite 21 along the West 

Fork of the Wallowa River is a heavy-use site, while campsite 22 on the West Fork of the Lostine River is a moderateuse site. 

The two campsites in timberline meadows had lost only 

10 percent of their vegetation cover, the change in 

species composition had been negligible, and there was 

only 3 to 4 percent more bare ground on campsites than 

on controls. These measures are dramatically lower than 

any of the other campsites studied. Visual impact is also 

less (fig. 17), as is reflected in the low condition class 

ratings of 1.0 and the impact ratings of 1.20 and 1.17. 

Although there is a popular belief that timberline 

meadows are unusually fragile, studies have consistently 

shown the relative resistance of Carex nigricans (black 

alpine sedge) meadows, the vegetation type in which 

these sites are located (Campbell and Scatter 1975; 

Hartley 1976). These meadows are susceptible to impact 

during early summer snowmelt, but by the time they dry 

enough to be usable, they are extremely durable sites. 

The lower elevation campsites, in contrast, have been 

as highly altered as the most heavily impacted subalpine 

forest sites (fig. 18). Only two other sites have higher 

overall impact ratings, and the reduction in duff depth on 

these sites is particularly severe. This supports the 

results of an earlier study in the Eagle Cap Wilderness 

which found that more vegetation change had occurred 

on forested sites, regardless of elevation, than on open 

grassland or meadow sites (Cole 1981a). 
Table 11.··Selected conditions and amount of change on campsites located iri alpine Carex nigricans meadows (15 and 20) and 

forests below 2 000 m (21 and 22) 

Campsites 

Impact parameter 15 20 21 22 

Bare area (m2

) 2 101 68 

Mutilated trees (percent) 100 100 

Camp seedlings (number/ha) 0 0 

Control seedlings (number/ha) 0 3,980 

Absolute change (number/ha) 0 3,980 

Relative change (percent) 0 100 

Camp vegetation (percent) 88 80 3 5 

Control vegetation (percent) 98 90 60 40 

Absolute change (percent) 10 10 57 35 

Relative change (percent) 10 11 95 88 

Camp bare ground (percent) 5 4 20 35 

Control bare ground (percent) 

Absolute change (percent) -4 -3 -19 -34 

Relative change (percent) -400 -300 -1,900 -3,400 

Camp duff depth (em) 0.3 0.6 0.1 

Control duff depth (em) .9 3.4 1.0 

Absolute change (em) .6 2.8 .9 

Relative change (percent) 67 82 90 

Floristic dissimilarity (percent) 25 37 53 84 

Condition class 1.0 1.0 4.0 3.5 

Impact rating 1.20 1.17 2.43 2.38 

23 
Figure 17.--Campsite 20 is located in a timberline meadow at Glacier Lake. 

Impacts were considerably less pronounced than on forested campsites. 

Figure 18.--Campsite 21 is located in lower elevation forests along the West 

Fork of the Wallowa River. Impacts were as pronounced as on campsites 

located in subalpine forests. 

24 
Are Lakeshore Sites Particularly Fragile? 

Lakeshore setbacks are becoming increasingly common 

in wilderness. Eagle Cap Wilderness regulations prohibit 

camping within 200 ft (61 m) of any lake. A common 

justification for this practice is that lakeshores are more 

fragile than sites set back from the lake. This supposition 

was tested by comparing conditions on five heavy-use sites 

located within 200 ft (61 m) of lakes and five heavy-use 

sites located more than 200 ft (61 m) from lakes. 

For the last few years, camping has been prohibited on 

the lakeshore sites, but enforcement has been difficult. We 

observed approximately the same numbers of parties still 

camping on illegal sites as on legal sites. Moreover, lakeshore sites were almost always the longest established 

sites and the sites that traditionally have received the 

most use. Therefore, in generalizing about the use history 

of these two sets of sites, one can safely assume that 

most lakeshore sites have been more heavily used for 

a longer period of time, but that in recent years, both 

sets have received relatively similar amounts of use. 

In comparison to setback sites, lakeshore sites tend to be 

somewhat larger, but less of the site is devoid of vegetation 

(table 12). They have fewer seedlings, but more vegetation 

cover. with a species composition that has been less highly 

altered than that on setback sites. Bare ground is less 

extensive, but the organic horizons are thinner. Soil pH, 

Ca concentration, and bulk density are all lower on lakeshore sites. Most of these differences are minor, however, 

in comparison to highly variable site conditions. 

Consequently, none of these differences were statistically 

significant at the 0.05 significance level using the 

Kolmogorov-Srnirnov two-sample test (Siegel 1956). 

Table 12.··Campsite conditions on lakeshore sites and sites located more than 200 feet from the lakeshore 

Lakeshore sites Setback sites 

(N =5) (N =5) 

Impact 

parameter Median Mean Median Mean 

Camp area (m2

) 219 233 ± 37 190 175 ± 76 

Bare area (m2

) 92 108 ±32 139 123 ± 66 

Seedlings (number/ha) 274 377 ± 301 637 994 ± 728 

Mutilated trees (percent) 96 90 ± 11 99 95±6 

Trees with exposed roots (percent) 40 38±25 38 41 ± 32 

Felled trees (percent) 34 29± 13 33 38± 17 

Scarred trees (percent) 17 21 ±28 5 22±24 

Floristic dissimilarity (percent) 50 58± 18 66 64 ± 11 

Vegetation cover (percent) 8 7±3 3 3±2 

Bare ground (percent) 24 37±25 41 43 ± 15 

Litter (percent) 59 50±24 50 48±20 

Duff depth (em) 0.13 0.16 ± 0.08 0.20 0.20 ± 0.14 

pH 5.40 5.48 ± 0.19 5.65 5.68 ± 0.13 

Instantaneous infiltration rate (em/min) 0.26 0.35 ± 0.25 0.28 0.29 ±0.03 

Saturated infiltration rate (em/min) 0.09 0.12 ± 0.08 0.14 0.13 ± 0.03 

Mg (p/m) 63 72±29 60 81 ±39 

Ca (p/m) 475 538 ± 195 587 762 ± 301 

Na (p/m) 56 60 ± 13 50 49±4 

Organic matter (percent) 19 23±8 17 16±4 

Bulk density (g/cm3

) 0.79 0.86 ± 0.20 0.95 0.98 ± 0.07 

Impact rating 2.2 2.2 ± 0.1 2.1 2.1 ±0.3 

25 
When relative and absolute amounts of change were 

compared, differences in the amount of change in seedling 

density and pH were the only statistically significant 

differences. Lakeshore sites had lost 97 percent of their 

seedlings, compared to 75 percent on sites set back from 

the lakes. Soil pH increased 9 percent on lakeshore 

campsites, compared to 13 percent on setback sites. For 

all of the other parameters measured, the amount of 

change was essentially the same on the two sets of sites. 

Given that seedling loss is the only impact which is more 

extreme on lakeshore sites, the contention that lakeshores 

are more fragile appears to be unfounded. In trampling 

experiments conducted in Waterton Lakes National Park. 

Nagy and Scatter (1974) found less vegetation change in 

a subalpine lakeshore meadow community than in the 

coniferous forests away from lakes. This is not to say, 

however, that there are no justifiable reasons for prohibiting camping close to lakeshores. 

Although water quality studies show little evidence of 

human health hazards associated with heavy use of backcountry lakes (Me Dowell 1979), there is some evidence that 

ionic concentrations and benthic plant populations can be 

altered by heavy use (Taylor and Erman 1979). Where lakes 

are uncommon and attract abnormally large numbers of 

visitors, there may be some danger that all of the lakes will 

be altered by human use. In this case, the justification for 

setbacks is not that lakeshores are more fragile, but that 

the lake ecosystem is rare and should receive special 

protection. 

Another justification for setbacks is that more trails tend 

to develop between campsites and the lakeshore when the 

site is located close to the lake. This causes more 

esthetic and ecological impact--not because the lakeshore 

site is more fragile, but because the flow of traffic between 

campsite and lakeshore is more destructive. 

There are also a number of sociological justifications. 

Lakes are commonly primary scenic attractions in 

wilderness areas and should, therefore, be left as pristine 

as possible. Moreover, parties camping on the lakeshore 

effectively claim that territory as their own, prohibiting 

other parties from having free access to the lakeshore 

(Hendee and others 1977). Finally, the perception of 

solitude is increased by moving people back from 

lakeshores because their visibility is decreased and noise 

does not carry as readily. 

Prohibitions on camping close to lakes keep visitors from 

camping where they most like to camp. The old, traditional 

campsites were inevitably located close to lakeshores. 

Managers will need good, justifiable rationales if they 

are going to convince visitors to camp away from the 

preferred lakeshores. The argument that mountain 

lakeshores are more fragile than adjacent areas is 

generally not tenable. Managers should carefully consider 

other justifications for setbacks and avoid basing policy on 

what is often an erroneous argument. 

26 

EVALUATION OF IMPACT INDICATORS 

Wilderness managers have recognized a need to monitor 

campsite impacts so they have some objective measure of 

the changes occurring on a site. Moreover, this is now a 

requirement under the National Forest Management Act. 

Most monitoring programs will not be able to measure 

change in the detail achieved in this study. More often, 

simple, rapid techniques which can be utilized by 

personnel with little training will be needed. 

One simple system. developed by Frissell (1978), uses 

condition classes based on visual criteria as follows: 

Condition Class 1. "Ground vegetation flattened, 

but not permanently inju-red. 

Minimal physical change except 

for.possibly a simple rock fireplace." 

Condition Class 2. "Ground vegetation worn away 

around fireplace or center of 

activity." 

Condition Class 3. "Ground vegetation lost on most 

of the site, but humus and litter 

still present in all but a few 

areas 

Condition Class 4. "Bare mineral soil widespread. 

Tree roots exposed on the 

surface." 

Condition Class 5. "Soil erosion obvious. Trees 

reduced in vigor or dead." 

We gave each campsite a condition class rating and then 

correlated these ratings and other possible impact 

indicators with campsite condition and change to see how 

well they predicted impact (table 13). 

Frissell's condition class rating was the indicator which 

correlated most highly with the overall impact ratings. It 

was also significantly correlated with more measures of 

impact than any of the other indicators. It is not surprising 

that condition class is correlated with trees with exposed 

roots, vegetation cover, or bare ground because these 

are characteristics used in the derivation of the rating. 

The rating, however, also predicted the amount of change 

in vegetation and bare ground that has occurred, as well 

as the change in duff depth, floristic dissimilarity, camp 

area, and bare area. These include most of the impacts 

which could be noticed by visitors, as well as all of the 

impacts which are related to amount of use. Soil impacts 

are notably unrelated to condition class. 

Camp radius and bare radius are impact indicators 

originally used in Olympic National Park by Schreiner 

and Moorhead (1976). Both of these indicators are 

significantly correlated with the overall impact ratings, 

although not as highly as condition class. Neither of 

these indicators are consistently correlated with any of 

the measures of impact intensity. They do, however, 

provide good estimates of the areal extent of impacts. 
Table 13.--Kendall tau correlation coefficients relating campsite impact parameters and impact indicators which might potentially be utilized 

in a monitoring program. Nonsignificant and redundant relationships have been left blank 

Condition Camp 

Impact parameter class radius 

Camp area 0.38 

Bare area .43 0.52 

Mutilated trees 

Trees with exposed roots .40 

Floristic dissimilarity .46 .36 

Seedlings 

Seedling change (absolute) .31 .40 

Seedling change (relative) 

Vegetation cover -.48 

Vegetation change (absolute) .39 

Vegetation change (relative) .50 

Bare ground .36 

Bare ground change (absolute) -.34 

Bare ground change (relative) -.33 

Duff depth 

Duff depth change (absolute) .31 

Duff depth change (relative) .32 

pH 

pH change (absolute) 

pH change (relative) 

Instantaneous infiltration 

Infiltration change (absolute) 

Infiltration change (relative) 

Bulk density 

Density change (absolute) -.33 

Density change (relative) 

Impact rating .50 .38 

Vegetation cover, bare ground, and trees with exposed 

roots are generally poor indicators of impact, although, 

surprisingly, vegetation cover is the best indicator of soil 

changes. Impact rating was included because it should 

have been highly correlated with the impact measures. It 

did not, however, predict amount of impact any better than 

condition class, despite the time and effort required to 

obtain the impact rating. 

At least, for the campsites studied, it appears that 

Potential indicators of impact 

Bare 

radius 

0.50 

.36 

.26 

.24 

-.35 

.33 

-.33 

-.32 

-.30 

.32 

27 

Vegetation Bare Trees with Impact 

cover ground exposed roots class 

0.35 

-0.37 .34 

-.27 0.41 

.59 

.49 

.44 .37 

0.26 

.32 

-.37 

-.32 -.39 

-.50 

.37 .48 

.47 .54 

.30 

.32 

.35 .28 

.35 .34 

-.36 .36 

.44 -.33 -.29 

.39 -.33 

.32 

Frissell's condition class rating is the best single 

indicator of campsite condition. Although it does not 

identify soil changes very well, it does provide a good 

indication of overall impact, as well as those changes that 

use management can influence--bare ground and duff 

depth, in particular. It also is correlated with the areal 

extent of impacts, although a supplemental measure of 

camp radius or bare radius could provide valuable 

additional information. 
There were a number of problems with the condition 

class ratings, however. The biggest problem was the 

breadth of some of the categories. Despite variability 

in site conditions, amount of change, and amount of use, 

71 percent of the campsites received a condition class 

rating of 4. In fact, much of the success of this system as 

an indicator of impact may simply be its ability to separate 

a few less heavily impacted sites from this majority of sites. 

To be useful, Condition Class 4 will need to be subdivided 

so that the concentration of consistently used campsites 

in this one class is not so high. 

Another major problem is that this rating does not 

describe the condition of individual measurable 

parameters. For example, it provides no baseline 

measure of vegetation cover that could be referred to at a 

later date to see if cover has changed. In other words, the 

rating provides a good measure of overall campsite 

condition, but little information about specific conditions. 

Managers desiring more specific quantitative information 

will need to use some other measure, such as percent bare 

ground or vegetation cover. 

Finally, many campsites could be given different ratings 

depending upon the evaluative criteria chosen. For 

example, some campsites had exposed tree roots 

(Condition Class 4), but little bare mineral soil (Condition 

Class 3). We gave these sites a rating of 3.5. Perhaps a 

system of separate subjective ratings of ground vegetation, 

bare mineral soil, tree root exposure, and soil erosion, the 

main criteria in Frissell's system, along with a measure of 

areal extent, could avoid most of these problems and still 

remain highly correlated with overall impact. More 

research is obviously needed. 

CONCLUSIONS AND MANAGEMENT 

IMPLICATIONS 

The median campsite in this study has changed in the 

following ways: 

1. From 85 to 90 percent of the undergrowth vegetation has been removed from the 2, 150-fF (200-m2 ) camp 

area, leaving a sparse vegetation cover quite dissimilar 

in composition to undisturbed sites; 

2. About 30 percent of the organic litter layer has 

been worn away, exposing patches of mineral soil; 

3. This loss of vegetation and litter has been most 

pronounced toward the center of the site where essentially 

no vegetation persists and 50 percent of the organic 

horizons have been removed; 

4. Essentially all of the trees on the site have been 

damaged, at least slightly, by recreational use; onefourth of the trees have been felled and another one-fourth 

exhibit substantial trunk scarring; 

5. Soil erosion has exposed roots on about one-third 

of the trees; 

6. Over 90 percent of the seedlings have been 

eliminated; the few remaining seedlings are confined to 

sites protected from human trampling; 

7. The soil has been compacted, although even on the 

most highly disturbed parts of the campsites, bulk 

density has increased only 15 percent and infiltration 

rates have decreased only about 30 percent; and 

8. The organic content of the surface soil has 

28 

increased slightly, as have the pH and the concentration 

of exchangeable Mg, Ca, and Na ions. 

In order to utilize this information, the significance of 

these changes must be questioned. In terms of an ideal 

wilderness, all of these changes are significant because 

they represent deviations from natural conditions. This 

definition of significance cannot be practically applied to 

campsites, however, because some impact is necessary 

just to make the campsite functional. For example, the 

shrubby understory on most of these campsites must be 

removed before the site makes a comfortable sleeping area. 

Given that a certain amount of impact is inevitable whenever a campsite receives consistent and prolonged use, a 

significant impact might best be defined as any change 

which reduces the future utility anq desirability of the 

campsite. In other words, a significant impact would 

be any change that threatens to make the site either 

nonfunctional or undesirable. 

Most site impacts do not appear to sharply reduce site 

desirability. Although more definitive research is needed. 

most evidence suggests that visitors seldom notice or are 

bothered by impacts on campsites (Lucas 1979). In a 

study in Yosemite National Park, for example, Lee (1975) 

found that "the use of wood for fires, destruction of ground 

cover, damage to trees, and other ecological changes in a 

pristine environment had less influence on the visitor than 

the presence of 'unnatural' objects," such as litter, horse 

manure, or constructed facilities. 

Of the changes found on campsites, the impact most 

likely to decrease the future desirability of the campsites 

is the loss of seedlings and saplings which may forecast 

the eventual deforestation of campsites. A number of 

studies have shown that most campers prefer campsites 

that are shaded to those in the open (for example, 

Cordell and James 1972). Another study has shown that, 

contrary to their stated preferences, visitors to a developed 

campsite usually chose largely devegetated sites (Hancock 

1973). This suggests that maintenance of the overstory 

is probably more important than maintenance of the understory. It is also more feasible. Maintenance of native 

understory populations, except on protected sites, is 

realistically impossible because trampling cannot be 

eliminated. The overstory could be maintained by 

establishing tree seedlings on protected sites, behind 

logs or rocks where they will not be trampled, and then 

ensuring, through an educational program, that they are 

not cut down as they mature. 

The impact most likely to reduce the functional ability 

of a campsite is long-term erosion. While erosion was 

not directly measured in this study, tree-root exposure 

should provide some indication of the amount of erosion 

which has occurred on a site. When these sites are 

reexamined in 1984, we will have a better idea of the 

magnitude of long-term erosion. Informal observations 

suggest that severe erosion is rare because campsites are 

usually flat and because compaction reduces the 

detachability of soil particles, inhibiting erosion by 

surface runoff. Managers should, however, consider 

closing sites on which severe erosion is obvious. 

Those sites will eventually become unusable and, at that 

point, will be essentially impossible to rehabilitate. 

The common assumption that deteriorated campsites 

are a result of overuse is true by definition; their 
deteriorated conditions are a result of "too much" use. 

This study shows, however, that on the campsites 

studied, even a few nights of use per year are usually 

"too much," because this use causes most of the change 

which is likely to occur on a campsite. 

Of the 27 impact measurements taken, only seven 

increase significantly in magnitude when campsite use 

increases over the range of use included in this study 

(that is, about a fiftyfold increase from less than one 

night per year to perhaps as much as 50 nights per year). 

Reductions in seedling density, vegetation cover, and duff 

depth, and increases in bare ground, bare area, trees with 

exposed roots, and floristic dissimilarity of the undergrowth become more pronounced as use increases. For 

loss of seedlings and vegetation cover, more than 75 

percent of the change occurs, however, on light-use sites 

(fig. 19). In both cases, essentially any consistent annual 

use eliminates almost all of the seedlings and undergrowth. Thus, the statistically significant correlation with 

use does not seem to be very meaningful in either a 

biological or a managerial sense. 

The variables which do show meaningful differences 

related to amount of use are bare ground, bare area, 

duff depth, floristic dissimilarity, and trees with exposed 

roots. As use increases from light to moderate amounts, 

organic litter continues to be removed, creating more bare 

ground and reducing duff depth; more tree roots are 

exposed; the central area devoid of vegetation increases in 

size; and the composition of the undergrowth continues to 

change. The size of the site also appears to increase, 

although this difference was not statistically significant. 

As use surpasses moderate amounts--probably 10 to 20 

nights per year--further increases in use cause little 

additional change in any of the variables other than duff 

depth, which continues to decrease dramatically with 

increased use. 

(a) 

100 

~ 

Vl 

Vl 

Figure 19.--The relationship between a- 0 

-1 

mount of use and amount of impact for 0 

z 50 

those variables with a statistically signifi- .....J 

0 

cant relationship: (a) percent reduction in LJ...J 

LJ...J 

seedling density; (b) percent reduction in Vl 

0 vegetative cover; (c) absolute increase in 

bare ground; (d) percent reduction in duff 

depth; (e) bare area; (f) percent of trees with (e) exposed roots; and (g) floristic dissimilarity. 100 For each use category, the median change 

is expressed as a percentage of the highest ~ median value for any use category. ~ 0:: 

<( 50 LJ...J 

0:: 

<( 

co 

0 

L 

L 

The two major implications of these results are: 

1. Any annually repeated use of campsites in this 

environmental situation will cause major onsite ecological 

changes; 

2. Even fiftyfold use reductions will do relatively little to 

reduce campsite impacts. 

These results only apply strictly to campsites near lakeshores, in Abies lasiocarpa/Vaccinium scoparium forests 

of the Eagle Cap Wilderness, between 7,050 and 7,800 ft 

(2 150 and 2 400 m), on soils derived from granite bedrock. Similar results, however, were also reported by 

Fichtler (1980) in two Montana areas. Working in Abies 

lasiocarpa forests, with an undergrowth differenUrom that 

in Eagle Cap on volcanic soils between 5,600 and 7,250 

ft (1 700 and 2 200 m), he found tf.lat the only significant 

difference between light- and heavy-use sites was more 

exposed mineral soil on heavy-use sites. 

Less fragile sites, such as low-elevation grasslands, 

could probably support more use before near-maximum 

levels of impact were achieved, but even on a lowelevation campground in Pennsylvania in "abandoned 

field" vegetation on deep, well-drained and productive 

silt loam flood plain soils, LaPage (1967) found that "the 

relationship between barren ground and cumulative mandays of use weakened and disappeared entirely" after the 

campground was 3 years old. More research is needed, but 

it appears clear that low levels of annual use are sufficient 

to cause most of the change which is likely to occur on a 

site. In relatively fragile high-elevation forests where a 

large proportion of wilderness campsites are located, this 

threshold appears to be no higher than a few nights of use 

per year. 

In deciding how best to manage impacts, it is important 

to distinguish between impact intensity and the total 

aggregate area of impact. The conclusion of this study 

is that increasing or reducing use has very Iitie effect 

(b) (c) (d) 

~ 

Vl 0- Vl z£ £ 0 

-1 =>LJ...J Iz z OVl 1-o 

~~ a.._ 

~ LJ...JIou 1- LJ..JO:: w... => ;::: e:::u w...o LJ...J <(Z :::lLJ..J 

0 co - Cl 0:: 

LJ...J 

> 

M H L M H L M H L M H 

(f) (g) 

LJ...J 

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:s:o ~5 0 0::~ 

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M H L M H L M H 

USE USE USE 

29 
on impact intensity, such as the magnitude of vegetation 

loss. Impact intensity can be more effectively minimized 

through improved campsite location and changes in 

visitor behavior. 

The good condition of campsites in Carex nigricans 

meadows, in relation to forested sites, suggests the 

value of improved campsite location. Schreiner and 

Moorhead (1976), for example, have shown that the bare 

area of a campsite varies primarily with differences in 

vegetation. Many studies have shown that sites dominated 

by graminoids will usually suffer less vegetation loss than 

sites dominated by shrubs, such as those in this study. 

Managers might consider closing badly deteriorated 

sites, particularly those experiencing severe erosion, and 

opening new sites in more durable locations if necessary. 

Visitor behavior can be changed through either 

minimum-impact camping education or regulations on 

type of use. A change in visitor behavior could eliminate 

the scarring and felling of trees and reduce some of the 

impact on soii chemistry through more careful use of fire 

and reduced pollution. On the other hand, it can do little 

to reduce vegetation and litter loss, the increase in bare 

ground, and soil compaction. These are inevitable 

consequences of use that are probably acceptable to 

most visitors, and, in most cases, pose no threat to the 

long-term usefulness or desirability of the campsite. It 

might be worth informing people of the problem with tree 

reproduction, however, in the hope that they might be 

careful to avoid trampling established seedlings. 

Regulations on type of use could also be useful. If 

effective, a campfire prohibition could at least reduce 

damage to live trees and changes in soil chemistry. Keeping horses out of camp areas could reduce damage to trees, 

trampling of seedlings and other undergrowth, soil 

erosion and tree root exposure, and the size of campsites. 

Managers must decide if the potential for improvement in 

site conditions is worth the imposition of regulations. 

In contrast to its limited effect on the intensity of 

impacts on existing campsites, use redistribution could 

have a pronounced effect on the total aggregate area of 

impacts. In areas where the amount of use is high enough 

that annually repeated use of campsites--even once a 

year in many places--is likely to occur, the area of impact 

could be reduced by encouraging repetitive use of fewer 

campsites. Use dispersal, in this situation, will usually 

increase the number of deteriorated campsites, 

with little compensatory improvement in conditions on 

former heavy-use sites. In the Eagle Cap Wilderness, 

for example, we heard complaints that many areas that 

were pristine a few years ago now have impacted campsites. 

In areas that receive at least moderate amounts of use, 

such as all the lakes in this study reached by trail, 

30 

repetitive use of few sites could probably be achieved by 

merely asking people to camp on previously used sites. 

In most areas, it should not be necessary to officially 

designate "legal" campsites, as many areas in the National 

Park Service and Parks Canada do. Impacts could then be 

further reduced by closing some campsites in areas having 

more campsites than necessary. Some lakes in the Eagle 

Cap Wilderness, for example, are encircled by more than 

100 campsites. 

In areas where use is very low, dispersal could minimize 

impacts. This policy requires extreme caution, however, 

to insure that repeat use of sites does not occur before the 

site can recover. If it does, campsites will deteriorate over 

time and the number and total aggregate area of campsite 

impacts will increase greatly. 

A program of education in minimum-impact camping 

techniques is a prerequisite for a dispersal policy. 

Visitors must be well educated before dispersal will work. 

Many National Park Service and Parks Canada areas also 

prohibit fires in areas of dispersed camping to reduce the 

potential for campsite change. A final necessity is a 

monitoring program capable of evaluating how well the 

program is working. 

Many types of monitoring programs could be suggested. 

In highly dispersed-use settings, an inventory of sites 

showing signs of human use may be adequate. In areas 

which receive more consistent use, more information on 

site conditions would be desirable. If a manager does not 

need quantitative baseline data on specific campsite 

conditions, such as amount of vegetation cover, some 

modified7 version of Frissell's condition classes would 

provide a good measure of overall site condition. When 

combined with a measure of campsite or bare area, an 

inventory of campsites utilizing these two measures 

should enable the manager to identify trends both in the 

intensity of impact on individual sites and the areal spread 

of impacts, either through the enlargement of sites or the 

pro I iteration of new campsites. 

In many cases, however, managers may need more 

detailed information on site conditions. Measurements of 

this type are much more costly because they require 

precise replication of previous measurements. Our 

research suggests that percent bare ground measurements 

are probably the most valuable because, unlike most 

impact parameters, bare ground varies in response to 

amount of use. Managers could attempt to manage use in 

such a manner that bare ground does not increase. Once 

the cost of precise replication is accepted, however, 

additional measurements are relatively cheap and 

should be given serious consideration. In particular, 

some measure of the campsite or bare area should be taken 

to supplement measures of impact intensity. 

7 1n addit1on to modifying some of the overly broad categor1es. 

managers may also need to redef1ne categones to more accurately reflect 

the1r environmental s1tuat1on. As suggested previously. a system of separate 

subJeCtive rat1ngs of ground vegetat1on. bare mmerai soli. tree root 

exposure. and soli eros1on. the ma1n cr1ter1a of Fr1ssell s system. along w1th 

any addit1onal parameters of concern. m1ght be particularly useful 
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1976. Ecological carrying capacity research: Yosemite 

National Park. Part 1. The effects of human trampling 

and urine on subalpine vegetation, a survey of past 

and present backcountry use, and the ecological 

carrying capacity of wilderness. U.S. Dep. Commerce, 

Natl. Tech. lnf. Cent. PB-270 955, 247 p. 

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Hoffmann, and P. Monti. 

1979. Effects of camping recreation on soil, jack pine 

(Pinus banksiana), and understory vegetation in a 

northwestern Ontario park. For. Sci. 25:233-249. 

Landals, M., and G. W. Scatter. 

1973. Visitor impact on meadows near Lake O'Hara, 

Yoho National Park. Can. Wild I. Serv. Rep., Edmonton, 

Alta. 184 p. 

LaPage, Wilbur F. 

1967. Some observations on campground trampling and 

ground cover response. USDA For. Serv. Res. Pap. 

NE-68, 11 p. Northeast. For. Exp. Stn., Broomall, Pa. 
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1963. An evaluation of campground conditions and 

needs for research. USDA For. Serv. Res. Note PSW-4, 

8 p. Pac. Southwest For. and Range Fxp. Stn., 

Berkeley, Calif. 

Merriam, L. C., Jr., C. K. Smith, D. E. Miller, and others. 

1973. Newly developed campsites in the Boundary 

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1969. Effects of high soil density on seedling root 

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Monti, P., and E. E Mackintosh. 

1979. Effect of camping on surface soil properties in 

the boreal forest region of northwestern Ontario. 

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1979. The impact of recreational land use on chemistry 

in a provincial park. Park News 15:22-25. 

32 

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43:589-593. 
APPENDIX 

THE DISTRIBUTION OF VASCULAR PLANT SPECIES ENCOUNTERED ON CAMPSITES OR CONTROL PLOTS. 

Frequency of occurrence 1 Mean cover2 Mean relative cover 2 

Species Camps Controls Camps Controls Camps Controls 

Achillea millefolium 0 3 0 + 0 0.4 

Agrostis thurberiana 0 + 0 0 + 

Agrostis variabilis 4 4 + .4 0.4 .3 

Allium validum 0 2 0 + 0 + 

Antennaria alpina 4 16 0.2 1.0 1.5 1.6 

Antennaria lanata 9 14 .3 2.1 2.5 3.4 

Antennaria microphyl/a 0 1 0 + 0 .1 

Arabis lyallii 1 0 + 0 .7 d 

Arabis sp. 0 1 0 + 0 .1 

Arenaria aculeata 0 5 0 .1 0 .4 

Arnica cordifo/ia 3 0 .1 0 .3 

Arnica mol/is 1 5 .1 .5 .1 .5 

Arnica parryi 0 1 0 + 0 + 

Aster alpigenus 5 4 .1 .3 1.4 .4 

Carex geyeri 1 2 .1 .1 .8 .2 

Carex luzulina 0 1 0 + 0 + 

Carex microptera 4 5 .2 1. 7 2.6 1.7 

Carex nigricans 2 + .5 .1 .8 

Carex rossii 19 20 .6 1.2 13.4 3.0 

Carex scopulorum 0 2 0 0.5 0 0.5 

Carex spectabilis3 5 6 0.3 .3 2.6 .7 

Cassiope mertensiana 2 3 + .3 + .2 

Castilleja chrysantha 1 6 + .2 + .2 

Danthonia intermedia 3 6 + .4 .4 .4 

Deschampsia caespitosa 0 2 0 .6 0 .5 

Dodecatheon alpinum + + + + 

Epilobium alpinum 2 2 + + + + 

Epilobium angustifolium 1 6 + .1 + .1 

Epilobium sp. 0 0 + 0 + 

Erigeron peregrinus 9 16 .1 1.2 2.9 1.5 

Eriogonum flavum piperi 0 0 + 0 .3 

Eriogonum ovalifolium 3 + + .3 + 

Festuca viridula 4 14 .3 1.6 2.1 2.4 

Gaultheria humitusa 1 5 + .6 .1 .6 

Gayophytum humile 2 + + + + 

Gentiana calycosa 0 2 0 .2 0 + 

Hieracium albertinum 2 0 + 0 .3 

Hieracium gracile 4 14 + .3 .3 .6 

Holodiscus discolor 0 1 0 + 0 .1 

Hypericum anagalloides 0 + 0 + 0 

Hypericum formosum 0 6 0 0.4 0 0.4 

Juncus drummondii 1 3 + + .2 + 

Juncus mertensianus 0 0 + 0 + 

Juncus parryi 20 21 1.7 6.2 21.2 12.4 

Ledum glandulosum 4 + .7 + .6 

Lewisia pygmaea 0 + 0 + 0 

Ligusticum tenuifolium 4 5 + .1 + .1 

Linanthastrum nuttallii 0 0 + 0 + 

Lonicera utahensis 0 0 + 0 + 

Luzula campestris 0 1 0 + 0 + 

Luzula hitchcockii 7 9 .4 1.8 4.7 2.9 

Muhlenbergia filiformis 9 10 .2 .9 2.5 .7 

Continued 

33 
APPENDIX (Con.) 

THE DISTRIBUTION OF VASCULAR PLANT SPECIES ENCOUNTERED ON CAMPSITES OR CONTROL PLOTS. 

Frequency of occurrence 1 Mean cover2 Mean relative cover2 

Species Camps Controls Camps Controls Camps Controls 

Oryzopsis exigua 1 6 + .1 .8 .5 

Osmorhiza chilensis 0 0 + 0 + 

Parnassia fimbriata 0 0 + 0 + 

Pedicularis contorta 0 1 0 + 0 + 

Penstemon fruticosus 0 2 0 + 0 .2 

Penstemon rydbergii 1 4 0 .3 .4 .6 

Phleum alpinum 4 4 + .3 .• 2 .2 

Phyl/odoce empetriformis 12 18 .3 8.8 4.5 10.6 

Poa annua 1 0 + 0 .1 0 

Poa gracillima 0 0 + 0 + 

Poa leibergii 0 1 0 + 0 .1 

Poa sandbergii 0 1 0 + 0 + 

Poa sp. 0 2 0 + 0 + 

Polemonium pulcherrimum 4 + 0.1 + 0.4 

Polygonum phytolaccaefolium 4 + .2 1.2 .4 

Potentilla diversifolia 0 1 0 + 0 + 

Potentilla flabellifolia 5 6 .1 2.1 .9 1.8 

Potentilla glandulosa 0 0 + 0 .1 

Potentilla gracilis glabrata 0 1 0 + 0 + 

Ranunculus eschscholtzii 0 2 0 + 0 + 

Ranunculus populago 1 1 + + + + 

Sagina saginoides 2 0 .1 0 .9 0 

Senecio cymbalarioides 0 2 0 .5 0 .3 

Spergularia rubra 1 0 + 0 + 0 

Trisetum spicatum 0 6 0 .4 0 .7 

Trisetum wolfii 0 0 .2 0 .1 

Vaccinium caespitosum 4 .1 .7 .5 1.5 

Vaccinium scoparium 19 21 .6 19.1 12.6 26.4 

Veratrum viride 1 2 + + .2 + 

Veronica cusickii 9 14 .2 1.9 1.9 2.6 

Veronica serpyllifolia 1 0 + 0 + 0 

Veronica wormskjoldii 1 0 + 0 + 0 

Viola adunca 3 5 + .3 .1 .3 

1 Number of sites out of a maximum of 22 on which the species was found. 

2Mean cover is the actual canopy coverage of the species, while relative cover expresses actual cover as a percentage of the total 

cover on the site. A plus ( +) indicates less than 0.1 percent cover. 

3This species was determined by Charles Feddema to be C. tolmei Boott, which Hitchcock and Cronquist (1973) consider to be 

synonymous with C. spectabilis. Some authorities equate C. tolmei with C. paysonis Clokey (Hermann 1970). 

'- U.S. GOVERNMENT PRINTING OFFICE: 1982-576-026/140 Region No.8 

34 
Cole, David N. 

1982. Wilderness campsite impacts: effect of amount of use. USDA For. 

Serv. Res. Pap. INT-284, 34 p. lntermt. For. and Range Exp. Stn., Ogden, 

Utah 84401. 

Subalpine lakeshore campsites were studied in the Eagle Cap Wilderness, 

Oreg. Light-use campsites had experienced almost as much alteration as 

moderate- and heavy-use sites. Sites set back from lakeshores had changed 

as much as lakeshore sites. Selected indicators of ecological change were 

evaluated. Implications of this research to management of wilderness 

campsites are discussed. 

KEYWORDS: ecological impact, campsites, wilderness management 


The Intermountain Station, headquartered in Ogden, 

Utah, is one of eight regional experiment stations charged 

with providing scientific knowledge to help resource 

managers meet human needs and protect forest and range 

ecosystems. 

The Intermountain Station includes the States of 

Montana, Idaho, Utah, Nevada, and western Wyoming. 

About 231 million acres, or 85 percent, of the land area in the 

Station territory are classified as forest and rangeland. These 

lands include grasslands, deserts, shrublands, alpine areas, 

and well-stocked forests. They supply fiber for forest industries; minerals for energy and industrial development; and 

water for domestic and industrial consumption. They also 

provide recreation opportunities for millions of visitors each 

year. 

Field programs and research work units of the Station 

are maintained in: 

Boise, Idaho 

Bozeman, Montana (in cooperation with Montana 

State University) 

Logan, Utah (in cooperation with Utah State 

University) 

Missoula, Montana (in cooperation with the 

University of Montana) 

Moscow, Idaho (in cooperation with the U niversity of Idaho) 

Provo, Utah (in cooperation with Brigham Young 

University) 

Reno, Nevada (in cooperation with the University 

of Nevada)