United States Department Trends in Campsite Condition...

United StatesDepartmentof Agriculture

Forest Service

lntermountainResearch Station

Research PaperINT-453

April 1992

Trends in Campsite Condition:Eagle Cap Wilderness, BobMarshall Wilderness, andGrand Canyon National ParkDavid N. ColeTroy E. Hall

National Park

THE AUTHORS

DAVID N. COLE is research biologist and ProjectLeader for the lntermountain Station’s WildernessManagement Research Work Unit at the ForestrySciences Laboratory, Missoula, MT. Dr. Cole receivedhis B.A. degree in geography from the University ofCalifornia, Berkeley, in 1972. He received his Ph.D.degree, also in geography, from the University ofOregon in 1977. He has written many papers onwilderness management, particularly the ecologicaleffects of recreational use.

TROY E. HALL was a forestry technician with theWilderness Management Research Work Unit. Ms.Hall is currently a graduate student in the Departmentof Forest Resources, Oregon State University,Corvallis. She received a B.A. degree in anthropologyfrom Pomona College in 1985 and an M.A. degree,also in anthropology, from Duke University in 1990.

ACKNOWLEDGMENTS

I am grateful to the many field assistants whocollected data in each of these areas. Financialsupport was provided, in part, by the Western Re-gional Office, National Park Service, U.S. Departmentof the Interior, and Grand Canyon National Park.

RESEARCH SUMMARY

Changes in the condition of well-established camp-sites were followed in three backcountry areas: EagleCap Wilderness in Oregon, Bob Marshall Wildernessin Montana, and Grand Canyon National Park inArizona. The period over which change was followedvaried from 5 years at Grand Canyon to 11 years atEagle Cap.

In all three areas, there was tremendous variation inresponse, both between and within campsites. Certaincampsites improved, while others deteriorated, andothers were relatively unchanged. Moreover, onindividual sites, certain types of impact became morepronounced while other types diminished. The meanresponse of all campsites, at Grand Canyon and EagleCap and of recently used Bob Marshall sites, was oneof slight deterioration. This suggests that there is littlereason to be either optimistic or pessimistic about thefuture condition of established campsites. Continueduse of these sites may cause further deterioration butat rates that are low when compared with the amountof impact that has already occurred._ On the otherhand, apparent decreases in visitor use in recent yearsand attempts to mitigate campsite impact have not ledto improved campsite conditions.

The types of impact that most frequently increasedover time were campsite expansion, exposure ofmineral soil, and damage to trees. In contrast, impactsto ground cover vegetation tended to decline or werestable in all three areas.

Changes on high-use and low-use sites werecompared in Eagle Cap and Grand Canyon. In bothcases high-use sites were more highly impacted thanlow-use sites, and the difference between low-use andhigh-use sites increased over the study period. Withfew exceptions, high-use sites either deteriorated orwere stable. The response of low-use sites was morevariable. Certain low-use sites deteriorated as muchas the high-use sites, while others improvedsubstantially.

In all three areas, change was followed on sites thatwere no longer being camped on. The response ofthese sites was highly variable, apparently dependingon previous impact levels and on environmentalcharacteristics. Generally, more highly impacted sitesrecovered more slowly than lightly impacted sites. Inaddition, sites with fertile and well-watered soils andsites with long growing seasons recovered well.

CONTENTS

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1Eagle Cap Case Study . . . . . . . . . . . . . . . . . . . . . .._...................... 1

Study Area and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Changes on All Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Factors That Influence Amount of Change . . . . . . . . . . . . . 8Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._....12

Bob Marshall Case Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Study Area and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Changes on All Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Factors That Influence Amount of Change . . . . . . . . . . . 16Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Grand Canyon Case Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Study Area and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Changes on All Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Factors That Influence Amount of Change . . . . . . . . . . . 26Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Discussion and Management Implications . . . . . . . . . . . . . . . 31Methodological Problems and Implications . . . . . . . . . . . . . . 33References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._.... 33Appendix 1: Frequency and Mean Cover of

Species on Campsites and Control Sites inthe Eagle Cap Wilderness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Appendix 2: Frequency and Mean Cover ofNonnative Species on Campsites in theBob Marshall Wilderness . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._.._.... 37

Appendix 3: Frequency and Mean Cover ofSpecies on Campsite Perimeters and ControlSites in Grand Canyon National Park . . . . . . . . . . . . . . . . . . . 38

lntermountain Research Station324 25th Street

Ogden, UT 84401

Trends in Campsite Condition:Eagle Cap Wilderness,Bob Marshall Wilderness, andGrand Canyon National ParkDavid N. ColeTroy E. Hall

INTRODUCTION

More than 25 years ago the Wilderness Act cre-ated the National Wilderness Preservation System.Since then many changes have occurred, and thereare diverse opinions about whether conditions inwilderness have improved or deteriorated. But lackof longitudinal research data has made it difficult todraw conclusions about trends in wilderness condi-tions (U.S. GAO 1989). Trend data are needed forboth visitor use characteristics (Roggenbuck andLucas 1987) and resource conditions (Cole 1987b).Toward these ends, trend studies have been con-ducted on both wilderness visitors and campsite con-ditions in wilderness. This report describes changesover time in the condition of selected long-establishedcampsites in three wilderness/backcountry areas.Additional reports will describe trends in the num-ber and distribution of campsites, trail conditions,and visitor characteristics and preferences.

Of two studies of change on established wildernesscampsites, one described changes in conditions over9 years on seven open campsites in the BoundaryWaters Canoe Area Wilderness, MN (Merriam andPeterson 1983). Some sites improved, some deterio-rated, and some were relatively stable. On indi-vidual sites, certain types of impact increased whileothers decreased. The overall trend suggested wasone of slight deterioration over this period. The sec-ond study described changes in condition over 5 yearson campsites in the Eagle Cap Wilderness, OR (Cole1986a). One of the case studies reported here is acontinuation of this study for an additional 6 years.

The case studies reported here were conducted inthe Eagle Cap Wilderness, the Bob Marshall Wilder-ness, MT, and Grand Canyon National Park, AZ.These areas represent a spectrum of environments,use levels, and types of use. The Eagle Cap studywas conducted on forested sites in subalpine lakebasins. This wilderness receives moderate levelsof use, primarily by backpackers. The Bob Marshallstudy was conducted on lower elevation mountain-ous sites. Use levels are relatively low, but use by

outfitted parties and parties with packstock is un-usually high. The Grand Canyon study was con-ducted on desert sites. Use levels are relatively high,and all use is by backpackers.

The field methods and periods of study also variedbetween areas. The periods between measurementswere 11 years in the Eagle Cap, 9 years in the BobMarshall, and 5 years in the Grand Canyon. Conse-quently, each area is treated as a separate casestudy.

As will become apparent, the patterns of changethat occurred on these campsites are complex. Con-sequently, the results are presented in considerabledetail for the interested reader. Others might find iteasier to skip over much of the detail, concentratingon the conclusions presented at the end of each casestudy (pages 12, 20, and 30) and the discussion andmanagement implications section.

EAGLE CAP CASE STUDY

Study Area and Methods

In 1979, 26 campsites in the Eagle Cap Wildernesswere selected for study (Cole 1982); 22 of these siteswere in similar environmental situations-subalpineforests around lakes (fig. 1). They were all locatedbetween 2,150 and 2,400 m elevation in an Abieslasiocarpa / Vaccinium scoparium (ABLA/VASC)forest type on soils derived from granitic bedrock.These sites were stratified on the basis of estimateduse levels as follows: six light-use sites (less than 5nights per year), six moderate-use sites (10 to 20nights per year), and 10 heavy-use sites (more than25 nights per year). Six of the heavy-use sites werewithin 60 m of lakes. Around the time the studycommenced, these lakeshore sites were officiallyclosed to camping; the other four heavy-use siteswere farther from lakeshores and remained openfor camping. Four additional sites were in differentenvironments-two in timberline meadows (2,500m elevation) and two in midelevation forests (2,000m elevation) along riverbanks.

1

Figure l-Most of the study sites in the Eagle Cap Wilderness were in subalpine forestsclose to lakes (figure deleted due to poor reproduction.).

In 1984 all 26 of these campsites were revisited.Changes in the 5 years between 1979 and 1984 arereported in Cole (1986a). In 1990, 20 of these camp-sites were reexamined, including all four of the sitesin other environments, but only 16 of the ABLA/VASC sites. Of these 16, three were light-use sites,three were moderate-use sites, four were open high-use sites, and six were closed high-use sites. Althoughofficially closed, some camping continued on the lake-shore sites. Results will be presented (1) for all 20sites combined, (2) for low-use ABLA/VASC sitesin comparison to similar open high-use sites, and(3) for open high-use ABLA/VASC sites in compari-son to similar closed high-use sites.

Methods are described briefly as follows, and moredetail can be found in Cole (1982). Each sample siteconsisted of both a campsite and an undisturbedcontrol site in the vicinity. The distances from anarbitrarily established center point to the edge ofthe disturbed campsite and to the first significantamount of vegetation were measured along 16transects. This defined the camp area and thedevegetated central core area. Tree “seedlings”15 to 140 cm tall were counted within the camp

area, excluding any untrampled “islands”; largertrees were counted in the entire camp area. Treesthat had been damaged (for example, with trunkscars, nails, or broken branches), felled, or hadexposed roots were counted. In 1990, the centerpoint-a buried nail-was relocated. Distances tothe edge of the disturbed campsite and to the firstsignificant vegetation were remeasured, and newcamp and devegetated core areas were calculated.The boundaries of the 1979 camp area were reestab-lished; seedlings, damaged trees, felled trees, andtrees with exposed roots were counted in this area,as in 1979.

On each campsite, approximately 15 quadrats,1 by 1 m, were located along four transects, originat-ing at the center point and oriented perpendicular toeach other. The canopy cover of total ground vegeta-tion, exposed mineral soil, and each plant specieswas estimated for each quadrat. Coverages wereestimated to the nearest percentage if under 10 per-cent or, if over 10 percent, in 10 percent coverageclasses. The midpoints of each coverage class wereused to calculate mean coverages for the campsite.The thickness of organic horizons was measured at

2

four points between 1 and 2 m from the center point,along each transect. In 1990, nails at the end ofeach transect were relocated. This permitted preciserelocation of the transects and quadrats. Coverageswere estimated and organic horizon thickness wasmeasured, as in 1979.

On the control plots, which varied in size from 91to 201 m2, coverage of total ground vegetation, ex-posed mineral soil, and each plant species was esti-mated for the entire plot. Seedlings were countedon a 50-m2 subplot placed in the center of the con-trol. Organic horizon thickness was measured atfour regularly distributed points. Measurementswere repeated in 1990.

The magnitude of change over the 11 years between1979 and 1990 is expressed in three ways: (1) meanconditions in 1979 and in 1990; (2) the mean abso-lute amount of change, which is calculated by sub-tracting conditions in 1979 from conditions in 1990;and (3) to provide a different perspective on the mag-nitude of this change, absolute change, is divided byconditions in 1979 to obtain relative change. Al-though means are reported in the tables, medianvalues are often used in the text to describe the re-sponse of a “typical site.”

For some types of impact, campsite conditionschanged, but so did comparable conditions on thecontrol sites. In these situations changes caused bycamping are confounded by other causes of environ-mental change such as recent precipitation patterns.The “noise” resulting from these extraneous causeswas reduced by calculating two indexes that com-pare campsite and control conditions. The firstindex --absolute difference-- is the measure on thecontrol site minus the measure on the campsite.The second index --relative difference-- is absolutedifference expressed as a percentage of the measureon the control site. These indexes provide estimatesof how much impact has occurred on campsites.Change over time, in these indexes, can be attrib-uted to camping because broad environmentalchanges are factored out. Where both campsite andcontrol conditions change, these indexes are used forcomparative purposes.

The direction of response often varied betweensites; some sites would improve while others woulddeteriorate. Consequently, the number of sites thatresponded in each possible way is reported.

We evaluated the significance of the differencebetween conditions in 1979 and 1990 with theWilcoxon matched-pairs, signed-ranks test in thecases where data were not normally distributed.Where data were normally distributed, we used apaired t-test. Null hypotheses were rejected if prob-ability values were 0.05 or less. A significant differ-ence indicates a pronounced and consistent change,either toward improvement or deterioration. A

nonsignificant difference suggests either that condi-tions were generally unchanged or that conditionschanged but not in a consistent, direction. The mag-nitude of changes and the proportion of sites thatimproved, deteriorated, and stayed the same canbe used to decide between these two latter options.

To test the hypotheses that (1) heavy-use sites de-teriorated more than low-use sites and (2) open sitesdeteriorated more than closed sites, we used one-tailed nonparametric Mann-Whitney and parametrict -tests. Given the small sample sizes, the likelihoodof incorrectly accepting the null hypotheses (thatthere are no differences) is relatively high.

Changes on All SitesTrends for Individual Types of Impact-

Campsite area, the area visibly disturbed by camp-ing activities, increased significantly from a meanof 193 m2 in 1979 to 206 m2 in 1990 (table 1). Themedian site increased 10 m2, or about 4 percent.Thirteen of the 20 sites increased in size, while onlythree decreased in size. Decreases tended to belarger than increases, however. The median de-crease on sites that decreased in area was 59 m2,while the median increase on sites that increasedwas 17 m2. Most of the increases in area had oc-curred by 1984; mean area was actually higher in1984 (227 m2) than in 1990. Surprisingly, all butone of the closed sites increased in area. Conversely,all of the sites that were unchanged or that decreasedin size were sites that remained open to use.

In contrast to campsite area, the size of the devege-tated central core of the campsite decreased from amean of 92 m2 in 1979 to 69 m2 in 1990. This de-crease was not pronounced and consistent enough tobe statistically significant; 11 of the 20 sites experi-enced decreases. Although devegetated area de-creased on five of the open sites, most of the sizabledecreases in devegetated area occurred on closedcampsites. When only open sites are considered, themean devegetated area was virtually unchanged be-tween 1979 and 1996. Devegetated area was sub-stantially higher in 1984 than in either 1979 or1990, suggesting that this variable is subject to siz-able year-to-year fluctuations. For example, a fewsparse plants growing close to the center of the sitecan drastically reduce devegetated area, eventhough the total amount of vegetation cover on thecampsite has not increased substantially. Severalof the sizable reductions in devegetated area re-sulted from transplanting of plugs in the centerof largely barren sites (fig. 2).

Results for tree damage were mixed (table 1). Thenumber of damaged trees (those with nails, scars, orbroken branches) declined slightly, but so did the to-tal number of trees on each site. The number of

3

Table 1 -Mean change in size and tree damage on all 20 campsites,1 Eagle Cap Wilderness

StatisticCamp Devegetated Damaged Trees with Felledarea core area trees exposed roots trees

Conditions19791990

ChangeAbsoluteRelative (percent)

Number of sitesIncreaseDecreaseUnchanged

Significance

193 92 11 5 5206 69 10 7 5

13 -23 -1 1 07 -25 -9 20 0

13 5 6 10 43 11 10 3 84 4 4 . 7 8

0.04 0.08 0.19* 0.02* 0.641Absolute change is the condition in 1990 minus the condition in 1979. Relative change is absolute

change as a percentage of the condition in 1979. The significance of differences between 1979 and 1990was tested with the Wilcoxon matied-pairs, signed-ranks test, or with the paired t-test where denoted withan l .

Figure 2-The devegetated area on this Eagle Cap Wilderness campsite has been reducedsubstantially by transplanted plugs, but total vegetation cover remains low.

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felled trees was virtually unchanged. A decrease innumber of trees could have resulted either from theelimination of all traces of trees that had been felledor from measurement error (individual counts intree clumps involves some subjectivity). Both prob-ably occurred. The likelihood that the former oc-curred suggests that tree damage may be greaterthan the data suggest because trees that are com-pletely eliminated are not counted.

The most dramatic change involved the incidenceof tree root exposure, which increased from a meanof five trees in 1979 to seven trees in 1990. This in-crease is statistically significant and occurred on 10of the 18 sites that had trees on them. In 1979 themedian site had exposed roots on 30 percent of itstrees; median tree root exposure increased to 38 per-cent in 1984 and 48 percent in 1990. Tree damageis cumulative-new damage is not offset by recoveryfrom damage as it is for such impacts as vegetationloss. These data suggest a trend of continued slowincreases in tree damage.

Tree seedling density on campsites increased sig-nificantly from a mean of 457 seedlings per hectarein 1979 to 548 seedlings per hectare in 1990 (table 2).Seedling density increased on 12 of the 18 forestedsites, with the median site experiencing a 14 percentincrease. Simultaneously, seedling densities de-creased on control sites. Calculations of the relativedifference between campsites and controls indicatethat, in 1979, the median campsite had lost 92 per-cent of its seedlings. This loss had decreased to 89percent in 1984 and 80 percent in 1990. Althoughit is clear that seedling loss remains a significantimpact on campsites, the increase in the number

of surviving tree seedlings is unexpected, unex-plained, and encouraging.

Ground cover conditions changed somewhat be-tween 1979 and 1990 (fig. 3). Vegetation cover in-creased, although not enough to be statistically sig-nificant (table 2). The most substantial change wasan increase in mineral soil exposure from a mean of33 percent in 1979 to 44 percent in 1990. Mineralsoil exposure increased on 16 of the 20 sites. In afew cases, changes were dramatic. On one site, soilexposure increased from 7 percent in 1979 to 74 per-cent in 1990. The primary cause of soil exposure,then, was loss of litter cover from parts of the sitethat were not vegetated. (The litter category infigure 3 refers only to “exposed” litter-litter thatwas not underneath ground cover vegetation.)

In contrast to the campsites, ground cover condi-tions on control sites were relatively stable. Basedon the relative difference between campsites andcontrols, the median campsite, in 1979, had lost 87percent of its vegetation cover. The magnitude ofvegetation loss decreased over time-to 85 percentin 1984 and 81 percent in 1990. In 1979, the mediancampsite had 24 percent more exposed mineral soilthan controls. This difference increased to 42 per-cent in 1984 and 51 percent in 1990.

Despite this increase in the areal extent of soil ex-posure, the thickness of organic horizons in the cen-tral part of the campsite (where duff depth was meas-ured) was unchanged between 1979 and 1990 (table 2).Organic horizons, which were measured at points1 to 2 m from the center point, decreased on sevensites, increased on five, and stayed the same oneight. In 1979, organic horizons were already

Table 2 -Mean change in seedling density and ground cover conditions on all 20 campsites,1 Eagle Cap Wilderness

OrganicSeedling Vegetation Mineral horizon

Statisticdensity cover

Camp Control Camp Controlsoil cover

Camp Controlthickness

Camp Control

Conditions19791990



Significance

---No./ha---- ------------percent------------ ____________ -----cm----- _____

457 5,060 15 60 33 1 0.2 0.9548 3,335 19 60 44 3 0.2 0.9

91 -1,991 4 0 11 0 0 020 -39 27 0 33 0 0 0

12 2 12 4 16 7 5 84 15 7 4 3 3 7 94 2 1 11 1 9 8 2

0.09 0.001 0.13* 0.96* 0.02 0.05* 0.90 0.67

1Absolute change is the condition in 1990 minus the condition in 1979. Relative change is absolute change as a percentage of the conditionin 1979. The significance of differences between 1979 and 1990 was tested with the Wilcoxon matched-pairs, signed-ranks test, or with thepaired r-test where denoted with an * .

I I

C o n t r o l s i t e :40 60 60 100

1979

I

0I I 1

20 40 60 80 100

Cumulative Percent Relative Cover

Figure 3- Mean coverage of ground covercategories on campsites and control sites in1979 and in 1990, Eagle Cap Wilderness.

largely depleted close to the center of the site; thick-ness had been reduced a median of 75 percent incomparison to controls. By 1990, the median reduc-tion in thickness was 78 percent. This suggeststhat, currently, most ground cover disturbance is oc-curring away from the central part of the site.

Changes in vegetative characteristics were rela-tively minor. For vegetation cover, the trend wasone of slight improvement. Vegetation cover in-creased on 12 of the 20 campsites, although the me-dian change was an increase in cover of just 2 per-cent. The most dramatic improvement on a site thatwas being used was an increase in cover from 8 per-cent in 1979 to 22 percent in 1990 (on a site with acontrol cover of 60 percent). The most pronounceddeterioration was a decrease in cover from 8 percentin 1979 to 2 percent in 1990 (on a site with a controlcover of 30 percent).

Changes in species composition were even lesspronounced. Floristic dissimilarity-an index ofthe difference in composition between campsitesand controls (Cole 1978)-was virtually unchanged(table 3). In 1979 the mean floristic dissimilaritybetween campsites and controls, which theoreticallycan vary from 0 percent (no difference) to 100 per-cent (completely different), was 55 percent; in 1990it was 57 percent. Although the difference betweencampsites and controls increased on 12 of 19 sites,the median change was an increase of just 3 percent.To investigate further, we calculated the floristicdissimilarity, between years, for campsites and forcontrols. The mean dissimilarity for campsites was28 percent; the mean dissimilarity for controls was

Table 3 -Mean change in indexes of species compositionand diversity on all 20 campsites,1 Eagle CapWilderness

StatisticFloristic Species Simpson’s

dissimilarity richness index

Conditions19791990



Significance

Percent Number

55 12 0.2557 13 0.26

1 1 0.012 8 4

12 9 77 8 130 3 0

0.40 0.49* 0.69*

1Absolute change is the condition in 1990 minus the condition in1979. Relative change is absolute change as a percentage of thecondition in 1979. The significance of differences between 1979 and1990 was tested with the Wilcoxon matched-pairs, signed-ranks test,or with the paired t-test where denoted with an * .

17 percent. This indicates that species compositionon campsites is more variable, over time, than oncontrols. But the trajectory of change on campsitesis not away from the composition one would expecton undisturbed sites.

For both individual species and for growth forms,differences in relative cover, between campsites andundisturbed controls, were pronounced, but changesover time were not. For example, figure 4 shows themean relative cover of the four most common vascu-lar plant species. Juncus parryi and Carex rossiiincrease in relative cover on campsites; they areamong the species most resistant to camping disturbante. Vaccinium scoparium and Phyllodoce empe-triformis decrease in relative cover on campsites;they are relatively fragile species. However, changesover time are minimal for all four species. For thetwo resistant species, the difference between camp-sites and controls decreased slightly. For the twofragile species, the difference between campsites andcontrols was unchanged. Changes in the frequencyand cover of other species can be found in appendix 1.

Changes in the relative cover of different growthforms were also minor (fig. 5). In 1979, the relativecover of graminoids was significantly higher oncampsites than controls; graminoids were moreresistant to campsite impacts than other growthforms. Shrubs and bryophytes had lower relativecover on campsites than on controls, suggesting thatthese growth forms were relatively fragile. By 1990,differences between campsites and controls had de-clined for both graminoids and bryophytes; differ-ences increased for shrubs and forbs.

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Campsites

I I0 10 20 30 40 50

Control Sites

I0 10 20 30 40 50


Figure 4- Mean relative cover of four commonspecies on campsites and control sites in 1979and in 1990, Eagle Cap Wilderness.

Control Sites


Figure 4- Mean relative cover of growthforms on campsites and control sites in1979 and in 1990, Eagle Cap Wilderness.

Changes in species diversity were also minor.Species richness (the number of species in the 15-m2

quadrats) increased on nine sites and decreased oneight (table 3). The low-elevation site that was nolonger in use experienced an increase in richnessfrom 12 to 35 species. But aside from this site, themaximum increase was seven species and the maxi-mum decrease was also seven. Simpson’s index,which indicates the extent to which the vegetationis dominated by a small number of species, was alsovirtually unchanged. Because larger numbers indi-cate increased dominance (lower diversity), moresites increased in diversity than decreased, but the

mean change was only about 4 percent and notstatistically significant.

Overall Trends- These results suggest that cer-tain types of impact had already reached peak levelsby 1979, while others have continued to increasesince that time. The impacts that had already stabi-lized are generally those that occur to ground covervegetation: devegetated core area, seedling density,vegetation cover, and species composition. Groundcover vegetation is so fragile that damage occursquickly (Cole 1987a). Levels of vegetation damagestabilize quickly. Thereafter, conditions are unlikelyto change greatly unless there is a dramatic changein the amount or type of use.

The two types of impact that continue to intensifystrongly are exposure of tree roots (fig. 6) and in-crease in mineral soil exposure. These impacts re-sult from erosion of organic horizons and mineralsoil, impacts that are caused only by frequent use ora high-impact style of use (for example, tying horsesto trees) or that occur only after long periods of use.These two impacts were among the few found to bemore pronounced on frequently used campsites (Cole1982). Such impacts could conceivably be limitedthrough management of recreational use.

Campsite area is intermediate in response. Be-tween 1979 and 1984, campsite area increased sub-stantially on 10 of the 20 sites. However, between1984 and 1990, only three of these sites continuedto increase in size. The mean camp area increased13 percent between 1979 and 1984; between 1984and 1990 the mean camp area decreased 6 percent.This suggests that site area has stabilized on mostof these sites.

To assess overall impact, a summary impact rat-ing was calculated for each site. Impact indicatorsused in this summary rating were camp area, rela-tive difference in vegetation cover, absolute differ-ence in mineral soil cover, floristic dissimilarity,relative difference in seedling density, percentageof trees with exposed roots, and relative differencein duff depth. For each of these indicators, camp-sites were assigned a rating of 1,2, or 3 (low to highamount of impact). The impact rating is the meanof all types of impact that apply.

The mean impact rating increased from 2.0 in1979 to 2.1 in 1990. This change was not statisti-cally significant. Ten of the sites were relativelystable (impact ratings changed no more than 0.2).Impact ratings increased by more than 0.2 on sevensites and deteriorated by more than 0.2 on threesites. If substantial change were defined as achange in impact rating of more than 0.4, one sitedeteriorated substantially and two sites improvedsubstantially. More subjective evaluations of thechange data led to the same overall conclusions:

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Table 4- Mean change in campsite conditions on threelow- use and four high-use campsites,1 EagleCap Wilderness

StatisticAmount of useLow High

Camp area (m2)19791990Change

Devegetated core area (m2)19791990Change

Trees with exposed roots (No.)19791990Change

Vegetation cover (percent)19791990Change

Mineral soil exposure (percent)19791990Change

Organic horizon thickness (cm)19791990Change

Floristic dissimilarity (percent)19791990Change

Impact rating19791990Change

161 218193 26333 45

67 10955 135

-11 26

3 85 112 3

13 716 83 2

25 4335 6610 23

0.30.2

-0.1

0.10.1

0

48 5247 62-1 9

1.6 2.21.7 2.60.1 0.4

1Change is the condition in 1990 minus the condition in 1979.

1979 to 135 m2 in 1990; the mean area on low-usesites decreased 11 m2, from 67 m2 in 1979 to 55 m2 in1990. Vegetation cover increased between 1979 and1990 on both categories of site, but the increase wasmuch greater on low-use sites. Mineral soil expo-sure increased on most sites, but again, the increasewas much greater on high-use sites. Only for loss oforganic horizons did the difference between low-useand high-use sites decline between 1979 and 1990.This can be explained by the fact that, by 1979, or-ganic horizons were already virtually gone in thecentral portion of high-use sites.

In 1979, mean camp area was substantially loweron low-use sites than on more frequently used sites.

The difference was not statistically significant with95 percent confidence; however, it would have beensignificant with a lower confidence level of 90 per-cent. Between 1979 and 1990, mean camp area onhigh-use sites increased 45 m2; on low-use sites themean increase in area was 33 m2. As with deveg-etated core area, high-use sites are more impactedthan low-use sites, and the difference between high-use and low-use sites increased between 1979 and1990.

The impact ratings suggest that overall conditionsdeteriorated slightly on both categories of campsite(fig. 7). Deterioration was greater on the high-usesites, although the difference between use levels wasnot statistically significant. Again, given the smallsample to work with, statistical significance wouldnot be expected.

For certain types of impact, such as loss of vegeta-tion cover, conditions on the high-use sites were gen-erally stable, while they improved substantially onthe low-use sites. For other impacts, such as expo-sure of mineral soil, continued use exacted a toll onall sites, but the deterioration was most pronouncedwhere the use was heaviest. For most impacts,high-use sites are two or three times as highly im-pacted as low-use sites. Estimates of use levels sug-gest, however, that the high-use sites are used about10 times as frequently as the low-use sites.

Low HighAmount of Campsite Use

Figure 7- Change in overall impact ratingbetween 1979 and 1990 on low-use and high-use Eagle Cap campsites.

9

In addition to examining mean response, it is alsoworth assessing the variability of response acrossuse levels. One of the most significant findings inthe analysis of change on campsites between 1979and 1984 was that variability in amount of changedeclined as use level increased (Cole 1986a). Com-pared to high-use sites, low-use sites were muchmore likely to either improve or deteriorate substan-tially. The 1990 results confirm this tendency forlow-use sites to be more variable in response. Forexample, the low-use site at Bear Lake improvedsubstantially. Vegetation cover increased from 8 to22 percent, and the devegetated core area decreasedfrom 55 m2 to less than 1 m2. In contrast, the low-use site at Hidden Lake deteriorated more than manyof the high-use sites. Camp area increased by 82 m2

(the largest increase on any campsite), devegetatedcore area increased by 21 m2, the number of treeswith exposed roots increased from six to 12, andmineral soil exposure increased from 7 to 19 percent.All four of the high-use sites deteriorated substan-tially. To quantify this variability, the coefficient ofvariation for the change in impact index was calcu-lated. Variation was an order of magnitude higheron low-use sites (2.83) than on high-use sites (0.26).

The small sample size makes it risky to draw de-finitive conclusions about how amount of changevaries between sites that receive different amountsof use. On these few sites, however, differences inamount of impact, related to amount of use, are in-creasing over time. All of the high-use sites con-tinue to deteriorate slowly. Certain low-use sitesare improving, while others are deteriorating. Pre-sumably, variation in response on low-use sites re-flects differences in the amount or type of use thesites received over the period. On low-use sites, de-creases in amount of use or adoption of low-impacttechniques by users may be reflected in reduced im-pact. Changes in the amount or type of use eitherhave not occurred on the high-use sites or are notmanifested in improving conditions.

Open and Closed Sites- Of the 10 original high-use sites in the ABLA/VASC vegetation type, onlyfour are still open to camping. The other six areless than 60 m from lakes. Camping was prohibitedon these sites in the late 1970’s, and violators werecited or asked to move or both. Most of these sitesare still used occasionally, although use levels havebeen reduced dramatically. Day use of these sites isstill legal and commonly occurs. On two of the sites,active rehabilitation (soil scarification and trans-planting) was attempted.

In 1979 there were no significant differences be-tween these two sets of sites (table 5). Closures hadjust been instituted and were not being enforced.Between 1979 and 1984, camp area was the one

variable that increased significantly more on openthan on closed sites (Cole 1986a). But the open sitesappeared to be experiencing larger increases indevegetated core area and in the number of trees withexposed roots. These tendencies had intensified fur-ther by 1990. In 1990, the open sites had a signifi-cantly larger devegetated core and more trees with ex-posed roots than the closed sites. Between 1979 and1990, such deterioration was also significantly morepronounced on the open sites. Finally, open sites alsoexperienced a significantly greater increase in camparea between 1979 and 1990 (although open siteswere not significantly larger than closed sites in 1990).

The impact ratings suggest similar conclusions. In1979 the closed sites had a higher mean impact rat-ing, although the difference was not significant. Be-tween 1979 and 1990 the change in impact rating onopen sites was significantly greater than on closedsites. By 1990 the impact rating on open sites wassignificantly higher than on closed sites.

Variation in response was also much greater onclosed sites than on open sites. The coefficient ofvariation of the change in the impact rating was muchhigher on closed sites (13.15) than on open sites (0.26).Two of the closed sites deteriorated over the 11 years,two generally improved, and two were relatively un-changed. In contrast, all of the open sites deteriorated.

Earlier Conditions- Another factor that mightexplain response over the 11 years is the conditionof the campsite in 1979. One of the findings for theperiod between 1979 and 1984 was a relationship be-tween amount of change and impact rating in 1979(Cole 1986a). The sites that were more impacted in1979 were more likely to have improved in condition,while the sites that were less impacted in 1979 weremore likely to have deteriorated.

This relationship was reexamined for the period be-tween 1979 and 1990, and there was no correlationbetween amount of change and conditions in 1979.Within each use category, sites that were more highlyimpacted in 1979 tended to have either improvedmore or deteriorated less than those that were lessimpacted in 1979 (fig. 8a). On the closed sites, how-ever, the sites that were more highly impacted in 1979improved less than the sites that were less impacted(fig. 8b). None of these correlations are significant.

Although not conclusive, this pattern of responsesuggests (1) that when comparing sites that receivesimilar amounts of use, more lightly impacted camp-sites have more potential to deteriorate than morehighly impacted sites (highly impacted sites are al-ready close to maximum possible impact levels) and(2) that less-impacted sites can recover more rapidlythan more highly impacted sites. Both of these con-clusions confirm suggestions of previous research(Cole 1986a; Willard and Marr 1971).

10

Table 5- Mean change in conditions on four open high-use and six closed high-use sites,’Eagle Cap Wilderness

StatisticCamp area (m2)

19791990Change

Devegetated core area (m2)19791990Change

Trees with exposed roots (No.)19791990Change


Open Closed Significance

218 195 0.59263 204 .12

45 9 .04*

109 125 .69135 63 .0426 -63 .03

8 4 .5211 4 .033 0 .05*

6 4 .22*8 7 .38*2 3 .45*


Organic horizon thickness (cm)19791990Change

Floristic dissimilarity (percent)19791990Change

43 41 .9266 58 .3723 16 .46

0.10.1

0

52 67 .1762 68 .25

9 1 .15

0.20.1

-0.1

.37

.47

.50

Impact rating19791990Change1The significance of differences between open and closed sites was tested with the Mann-Whitney

U test, or with the t-test where denoted with an * .

2.2 2.3 .752.6 2.3 .080.4 0 .Ol l

1.0 2.0 3.0 1.0 2.0 3.0Impact Rating, 1979

Conclus ions

The principal conclusions to be drawn from thisstudy of 11 years of change on Eagle Cap campsitesare:

1. The general trend on established campsitesthat continue to be used is one of slight deterioration.

2. Trend varies between types of impact. Fewof these sites were experiencing any further loss ofseedlings or vegetation cover or any enlargement ofthe devegetated central core. On the other hand,most sites were experiencing substantial increasesin mineral soil exposure and in tree root exposure.Most sites experienced modest increases in camparea.

3. Differences in amount of impact between low-use and high-use sites are increasing with time. Allhigh-use sites are deteriorating. Certain low-usesites are deteriorating, while others are improving.Consequently, median conditions on low-use sitesare relatively stable, while they are deterioratingon high-use sites.

4. Although high-use sites are more highly im-pacted than low-use sites, differences in amount ofimpact are not as great as differences in the amountof use these sites receive. In this case, a site used 10times as frequently as another site would typicallybe only several times more highly impacted.

5. Differences in amount of impact between openand closed high-use sites are also increasing withtime. All open high-use sites are deteriorating. Cer-tain closed high-use sites are improving, while oth-ers are still deteriorating. Consequently, medianconditions on closed high-use sites are relativelystable, while they are deteriorating on open sites.

BOB MARSHALL CASE STUDY


In 1981,35 campsites in the Bob Marshall Wilder-ness were selected for study (Cole 1983a). Sites inboth grasslands and forests were selected, but allsites were at relatively low elevations for a moun-tainous wilderness in the Western United States(1,250 to 1,675 m). Only well-established sites wereexamined, although use levels ranged from the mostfrequently used sites in the area to sites used nomore than a few times per year. Six of the campswere used exclusively by backpackers. Twenty-fourwere used predominantly by private parties withstock (hereafter called horse camps), although theywere also used by backpackers and outfitters (fig. 9).Finally, five of the base camps assigned to outfitterswere studied.

In 1990, 29 of these sites were reexamined. Thesesites included five of the six backpacker sites, 19 ofthe 24 horse camps, and all five outfitter camps. Be-tween 1981 and 1990, however, one of the outfittercamps was dismantled and was no longer in use.It is also worth noting that the effective season atwhich this study was conducted differed betweenyears. In 1981 the survey was conducted betweenearly July and mid-August, and all the sites thatwere surveyed had been used that year. In 1990the survey was started a week earlier and was com-pleted by late July. More significantly, spring wasunusually wet that year and much of the back-country was difficult to access early. Consequently,only nine of the 29 sites had been used before thesurvey was conducted in 1990.

Results will be presented (1) for all 29 sites com-bined, (2) for the nine recently used sites in compari-son to the 20 sites that had not been used, and (3) forthe five backpacker sites in comparison with the 19horse sites and the four remaining outfitter sites.

With only a few exceptions, field methods wereidentical to those employed in the Eagle Cap study.Campsites and undisturbed control sites were mea-sured and compared. The primary differences onBob Marshall sites were: (1) the thickness of organichorizons was not measured; (2) soil penetration re-sistance was measured with a pocket soil penetrom-eter in the uppermost portion of the mineral soilwithin each quadrat; and (3) coverages were not es-timated for individual species, although total coverof nonnative (exotic) species was estimated.

Data analysis and presentation are similar to thatin the Eagle Cap study. To test the null hypothesisthat the type of use a campsite receives has no effecton either campsite conditions or amount of change,nonparametric Kruskall-Wallis and parametricone-way analysis of variance tests were used.

Changes on All Sites

Trends for Individual Types of Impact-Campsite area-the area visually disturbed bycamping activities-increased significantly from amean of 263 m2 in 1981 to 315 m2 in 1990 (table 6).The median site increased 29 m2, or about 12 percent.Sixteen of the 29 sites increased in size and 10 de-creased. Increases were typically larger than decreases.The median increase on sites that increased in sizewas 72 m2; this is a 34 percent increase in camp areain just 9 years. Two sites increased by more than300 m2 over these 9 years. No attempt was made toassess the increase in size of offsite areas disturbedby pack and saddle stock. These “stock-holding ar-eas” are typically at least as large as the campsitesand sometimes much larger (Cole 1983a).

12

In contrast, the size of the devegetated centralcore of the campsites decreased significantly froma mean of 41 m2 in 1981 to 34 m2 in 1990. Thisdevegetated core area decreased on 19 of the 29campsites. On the median site, the barren coredecreased by more than 50 percent.

Results for tree damage were mixed (table 6). Themean number of both damaged trees and trees withexposed roots decreased between 1981 and 1990;however, so did the total number of trees. On themedian site, 100 percent of trees were damaged,both in 1981 and 1990. This demonstrates the ex-tremely high levels of tree damage that characterizecampsites in the Bob Marshall. The fact that the to-tal number of trees (which includes felled and otherdead trees) declined from a mean of 25 in 1981 to 23in 1990 suggests an increase in tree damage. More-over, the mean number of felled trees increased sig-nificantly from three in 1981 to four in 1990. Onone site, the number of felled trees increased from13 in 1981 to 22 in 1990. There were no significantchanges in the number of trees with large scars(>l,000 cm2).

These data suggest that tree damage has in-creased but not substantially. It was impossible,however, to document precisely the changes in treedamage in the places where stock are kept. These“stock-holding areas” are where the majority of treedamage occurs (Cole 1983a). Notes and photographstaken in 1981 clearly show that damage had in-creased around many of the campsites by 1990.Some of the 1981 control sites had even been dam-aged when stock were confined on them. Therefore,the onsite tree data presented here substantially un-derestimates actual increases in tree damage.

In 1990, as in 1981, most sites had no tree repro-duction. Nineteen of the 29 sites experienced nochange in seedling density (table 7). However, in-creases in density were more common than decreases.Density increased on seven sites and decreased onthree sites. Three sites that had no seedlings onsitein 1981 had seedlings onsite in 1990, while only onesite that had seedlings onsite in 1981 had lost all re-production by 1990. In general, loss of reproductionis a severe and relatively unchanging impact onthese sites.

Table 7 -Mean change in seedling density, ground cover conditions, and soil penetration resistance on all 29 campsites, 1

Bob Marshall Wilderness

Statistic

Seedling Vegetationdensity cover

Camp Control Camp Control

Exoticspp. cover

Camp Control

Conditions19811990



Significance

56 1,247 33 85 16 1079 1,171 42 89 22 9

23 -75 9 4 5 -241 -6 27 5 31 -20

7 9 22 12 21 123 12 6 1 8 9

19 8 1 16 0 80.58 0.42 0.00l* 0.001 0.02 0.60

Mineral Penetration

Statisticsoi1 cover

Camp Controlresistance

Camp Control

Conditions19811990



S ign i f i cance

14 1 3.3 2.311 1 2.4 1.7

-3 0 -0.8 -0.6-21 0 -24 -26

9 5 4 618 6 23 21

2 18 1 10.58 0.89 0.001* 0.001

1Absolute change is the condition in 1990 minus the condition in 1981. Relative change is absolute change as a percentage of thecondition in 1981. The significance of differences between 1981 and 1990 was tested with the Wilcoxon matched-pairs, signed-ranks test,or with the paired t-test where denoted with an * .

Ground cover conditions on these sites improvedslightly between 1981 and 1990 (fig. 10). Vegetationcover increased significantly on campsites from amean of 33 percent in 1981 to 42 percent in 1990.Vegetation also increased significantly on controlsites, but changes on controls were less pronounced.The difference between campsite and control condi-tions decreased significantly over the 9 years. Basedon the relative difference between campsites andcontrols, the median site had lost 68 percent of itsvegetation cover in 1981. In 1990 the median losswas 56 percent.

Many of the plants that increased on campsiteswere nonnative species. Cover of these exotics in-creased from a mean of 16 percent in 1981 to 22 per-cent in 1990. Exotic species cover increased on 21 ofthe 29 campsites. The proportion of the vegetationcover that is nonnative increased from a mean of 39percent in 1981 to 45 percent in 1990. In the mostextreme case, one site that had 5 percent exotic veg-etation cover in 1981 had 55 percent in 1990. Therewere significant increases between 1981 and 1990 inthe number of exotic species on campsites, as well asin the number of quadrats in which exotic specieswere recorded. By 1990 the median campsite hadfour exotic species, and exotics were found in 12 ofthe 15 quadrats. So, although the increased vegeta-tion on these sites is encouraging, the fact that theprevalence of nonnative species is increasing onsiteis not encouraging. Data for individual nonnativespecies coverages can be found in appendix 2.

The capacity of these sites for vegetative growth isremarkable when compared with the slow revegeta-tion occurring on closed sites in the Eagle Cap. Theoutfitter site at Murphy Flats was dismantled in

1981

1990

Figure 10 --Mean coverage of ground covercategories on campsites and control sites in1981 and in 1990, Bob Marshall Wilderness.

1983. Since that time vegetation cover has in-creased from 30 to 66 percent, and the devegetatedcore has disappeared; in 1981 it had been 22 m2.In 1990 it was difficult to even find the campsite.A corral without any vegetation in 1981 could noteven be found in 1990 (fig. 11). Of the vegetationgrowing onsite, however, 84 percent consists ofnonnative species.

Mineral soil exposure decreased from a mean of14 percent in 1981 to 11 percent in 1990. Despitethe fact that exposure decreased on 18 of the 29sites, this change was not statistically significant.Changes were generally relatively small; two sitesexperienced increases in exposure that exceeded10 percent, and five sites experienced decreases ofmore than 10 percent. This result contrasts withthe pronounced increases in mineral soil exposurefound on Eagle Cap campsites.

When exposed, mineral soils are readily com-pacted by trampling. Soil penetration resistancein 1981 was much higher on campsites than on con-trols (table 7). Penetration resistance declined sig-nificantly between 1981 and 1990 on both campsitesand controls. This particular measure of soil com-paction varies greatly with soil moisture levels, andthe wet spring in 1990 resulted in substantiallylower values everywhere. Differences betweencampsites and controls did not change significantlybetween 1981 and 1990. The median absolute dif-ference between campsites and controls in 1981 was0.9 kg/cm2; this difference was 0.7 kg/cm2 in 1990.Differences between campsites and controls in-creased on 16 sites and decreased on 12 sites, sug-gesting no overall trend toward either deteriorationor improvement.

Overall Trends -These results suggest that mosttypes of impact had already reached peak levels by1981. Only increases in campsite area and treedamage appear to be continuing. Ground cover con-ditions appear to have improved substantially, al-though it is not clear whether to consider increasedcover by nonnative species to be improvement or de-terioration. Certainly a more complete vegetativecover, even if it is composed of exotics, will help toinhibit loss of organic matter, soil compaction, andincreased runoff and erosion.

To assess overall impact, each campsite was as-signed an impact index rating in 1981 and in 1990.This index is based on seven indicators of impact:vegetation loss, mineral soil increase, tree damage,tree root exposure, social trails, camp area, and bar-ren core camp area (Cole 1983b). Each variable israted as 1,2, or 3. The mean of these ratings is theimpact index, with 1.0 suggesting minimal impactand 3.0 maximum impact.

15

Table 8 -Mean changes on the nine sites that had already been used in 1990 and the20 sites that had not,1 Bob Marshall Wilderness

Statisic Used Unused SignificanceCamp area (m2)

1981 355 219 0.041990 499 228 .002Change 144 9 .OOl

Devegetated core area (m2)1981 78 24 .021990 65 20 .OOlChange -13 -4 .83

Vegetation aver (percent)1981 23 38 .ll*1990 24 50 .001Change 1 12 .83

Exotic species cover (percent)1981 15 17 .961990 15 25 .37Change 0 8 .04

Mineral soil exposure (percent)1981 18 12 .311990 18 8 .03Change 0 -4 .02

Impact index rating1981 2.7 2.4 .041990 2.6 2.0 .OOlChange -0.1 -0.4 .021The significance of differences between used and unused sites was tested with the Mann-

Whitney U test, or with the t-test where denoted with an *.

Clearly, sites that had not been used in 1990 im-proved more (or deteriorated less) than sites thathad been used in 1990. It is tempting to concludethat this greater improvement is a result of their nothaving been used that year-that seasonal recoveryis pronounced and that if we had taken measure-ments later in the season improvements would havebeen less pronounced. An alternative hypothesis,however, is that the unused sites are less frequentlyused than the used sites and, therefore, that differ-ences are not seasonal but instead reflect differencesin amount of use.

This alternative hypothesis can be evaluated bytesting whether the amount of impact on these twocategories of site differed significantly in 1981. If so,differences may reflect long-term recreational usepressures rather than seasonal pressures. In 1981the used sites were significantly larger, had a sig-nificantly larger devegetated core, and significantlyhigher impact index ratings. However, vegetationcover, exotic species cover, and mineral soil coverwere not significantly different.

There appears to be support for each of the twohypotheses. Clearly, some of the apparent improve-ment in conditions represents seasonal improvement

since the previous use season. In particular, a sur-prisingly high degree of vegetation recovery occursduring each off-season. Much of this regrowth willprobably be eliminated once use of these sites com-mences. This would suggest that the estimates ofchange on used sites (table 8) might be more accu-rate estimates of long-term change than those forall 29 sites. It is also clear, however, that the “usedsites were already more highly impacted in 1981.They are probably more frequently used than theother sites.

In sum, we believe that our estimates of changewould have been different if we had taken measure-ments later in the summer-at a time more season-ally equivalent to the 1981 measurements. We be-lieve that change values between those for all sitesand those for just the used sites would be most rep-resentative of the amount of change that has oc-curred on campsites. Quantitatively, this would re-sult in larger increases in camp area and smallerincreases in vegetation cover (fig. 12). Perhaps min-eral soil exposure would have increased slightly overthe 9 years instead of decreasing slightly. The mostsignificant change would be in the number of sitesthat deteriorated or improved. Of the nine “used’

17

sites, two deteriorated and five were stable; none im-proved. As in the Eagle Cap, more "used" sites weregenerally stable than changed, and more “used” sitesdeteriorated than improved.

Type of Use -Another factor that might influenceamount of change on these sites is the type of visitorthat typically uses the site. Five of the Bob Marshallcampsites were used primarily by backpackers, fourwere outfitter base camps, and 19 were used prima-rily by private horse parties. Mean conditions in1981 and in 1990, as well as the amount of changebetween 1981 and 1990, are shown in table 9 foreach of these user categories. Unfortunately, thesmall sample of backpacker and outfitter sites makesthe tests of statistical significance difficult to relyon. Many nonsignificant differences may have beensignificant if a larger sample of sites had been avail-able. Moreover, many of the most substantial im-pacts on the horse and outfitter camps occur outsideof the main camping area, in the places where stockare confined. Because we have no data for theseplaces for 1990, total impact is greatly underesti-mated on the horse and outfitter camps, making

them appear more similar in condition to back-packer sites than they really are. For example, in1981 the median camp area on outfitter sites was233 m2; however, the median disturbed area (campplus stock-holding area) was 3,143 m2 (Cole 1983a).The median number of trees with exposed roots onthe campsite was eight, but the median on thelarger disturbed site was 37.

There was abundant visual evidence of additionalimpact in the stock-holding areas-impact that, bydefinition, does not occur on the backpacker sites.We must conclude that, as in 1981, horse and outfit-ter camps remain many times larger than back-packer camps and they have many times the num-ber of damaged trees. We suspect that differencesbetween these types of camps (particularly in regardto the number of damaged trees in stock-holding ar-eas) increased between 1981 and 1990.

On the campsites proper, differences betweenthese three types of camp are less pronounced. In1981, backpacker camps were significantly smallerthan the other types (table 9). Between 1981 and1990 the mean size of all three site categories

Table 9 -Mean changes on five backpacker, 19 horse, and four outfitter campsites, 1Bob MarshallWilderness

StatisticType of use

Backpacker Horse Outfitter SignificanceCamp area (m2)

19811990Change

104 311 277 0.02111 374 364 .03

7 63 87 .62Devegetated core area (m2)

19811990Change


Exotic species cover (percent)19811990Change


Impact index rating

12 52 28 .4011 46 11 .42-1 -6 -17 .85

25 34 .44 .66*38 40 51 .75*13 6 8 .41*

3 16 39 .077 19 44 .104 3 5 .50

660

11 32 .0410 23 .08-1 -9 .71

increased, but the mean increase was greatest onoutfitter camps (87 m2) and least on backpackercamps (7 m2). So, in 1990, differences in camp areabetween backpacker sites and the other types wereeven greater than in 1981.

The other types of impact that were significantlyless pronounced on backpacker sites in 1981 weremineral soil exposure and the prevalence of exoticplant species. In contrast to camp area, these differ-ences did not increase over the 9 years. The amountof change in exotic species cover between 1981 and1990 was virtually identical on all three types ofsite. Mineral soil exposure declined on horse andoutfitter sites and was stable on backpacker sites.Consequently, differences declined. In 1981 themean mineral soil exposure on outfitter sites wasmore than five times that on backpacker sites; in1990, soil exposure on outfitter sites was less thanfour times that on backpacker sites.

The impact index ratings suggest that all threecategories of site have changed comparably-theyall have improved slightly. As mentioned earlier,however, this ignores changes in the stock-holdingareas. We frequently observed recent damage inthese places-recently exposed roots, felled trees,and churned-up ground (fig.. 13). Newly disturbedground cover may be offset by recovery elsewhere,suggesting that long-term deterioration may not beoccurring. However, the tree damage is cumulative;new damage is added to old damage. If new treesare being damaged, overall conditions must be dete-riorating. Consequently, the primary difference be-tween these three types of sites in the amount ofchange that occurred over this period is probablymore dramatic increases in tree damage in the stock-holding areas associated with horse and outfitter sites.

Earlier Conditions -We examined the relation-ship between amount of change between 1981 and1990 and the condition of the campsite in 1981. Wefound no correlation. This contrasts with the resultsof the Eagle Cap study, and it may reflect the largenumber of uncontrolled variables in the BobMarshall study (vegetation type, type of use, andamount of use).

C o n c l u s i o n s

The principal conclusions to be drawn from thisstudy of 9 years of change on Bob Marshall camp-sites are:

1. The general trend on established campsiteswas one of slight improvement. However, most im-provement occurred on sites that had not yet beenused during the 1990 season. When only “used”sites are considered, the general trend is one ofslight deterioration.

Figure 13 - Stock have recently been confinedin this area adjacent to a campsite, Bob MarshallWilderness. Note the exposed tree roots andchurned-up soils.

2. Regardless of whether all sites or only “used”sites are considered, most sites were relatively stable.

3. The types of impact that are continuing to in-crease are enlargement of campsite area and, per-haps, an increase in tree damage, particularly inplaces where stock are held.

4. Considerable seasonal recovery of vegetationoccurs on many of these sites. Moreover, once camp-ing is removed, as it was on one outfitter site, adense vegetation cover can reestablish rapidly onmany of these sites. Unfortunately, much of thecover consists of nonnative species.

5. Backpacker sites remain much less severelyimpacted than horse and outfitter camps. No sub-stantial differences in amount of change betweenthese three types of camp were documented. It wasapparent, however, that tree damage in offsite stock-holding areas is continuing to increase around horseand outfitter camps. Tree damage and the areal ex-tent of disturbance are the types of impact that areparticularly pronounced on horse and outfittercamps (Cole 1983a).

20

GRAND CANYON CASE STUDY


In 1984, 24 campsites in Grand Canyon NationalPark were selected for study (Cole 1986b). All siteswere located along "primitive" trails in the Park’sbackcountry but along neither the Colorado Rivernor the “developed” trail corridors (fig. 14). We se-lected 12 high-use and 12 low-use sites. The high-use sites were among the most heavily used back-country sites in the Park. They receive substantiallyheavier use than any of the Eagle Cap or BobMarshall sites. The low-use sites ranged from sev-eral that are virtually unused to others that areregularly used but at low levels. Within each usestratum, four sites each were located in pinyon-juniper; catclaw, and desert scrub vegetation types.

Twenty of these campsites were resurveyed in1989; the other four were resurveyed in 1990. Siteswere surveyed in April and May of each year. Con-ditions in 1984 were considered to be unusually dry;however, conditions in 1989 and 1990 were evenmore droughty. Results will be presented (1) for

all 24 sites combined, (2) for the 12 high-use and 12low-use campsites, and (3) for the eight sites locatedin the pinyon-juniper, catclaw, and desert scrub veg-etation types.

As in the other case studies, each sample site con-sisted of both a campsite and an undisturbed controlsite in the vicinity; however, the other aspects of themethodology differed. A point was established nearthe center of the disturbed core of the campsite. Thedistances from this point to the first significantamount of vegetation were measured along 16 cardi-nal directions. This defined the campsite core area.Within this core, four 1-m2 quadrats were locatedalong the north, south, east, and west transects,halfway to the edge of the core. Percentage cover oforganic litter was visually estimated in each quadratusing the following coverage classes: ‹l, l-5, 6-25,26-50, 51-75, 76-95, and 96-100 percent. Vegetationcover, by definition, was negligible in the core; how-ever, cover was estimated where it was present.Mean coverage was calculated using the midpointof each class. Ten penetration resistance readingswere taken in each quadrat with a pocket soilpenetrometer.

A second set of measurements was taken on thecampsite perimeter-the area immediately beyondthe core. About 25 quadrats of 1 m2 each were ran-domly located along transects in the campsite perim-eter. Within each quadrat, cover of live vascularvegetation, cryptogams, organic litter, mineral soil,and rock were estimated. The cover of each vascularplant species was estimated, and the number ofshrubs rooted in each quadrat was counted by spe-cies. Two penetration resistance readings weretaken in each quadrat.

Control sites were circular, with an area of 50 m2.They were close to the campsite in an area undis-turbed by camping but similar to the campsite interms of vegetation, substrate, slope, rockiness, anddistance from water. Within this area all rootedshrubs were counted, and the cover of live vascularvegetation, cryptogams, organic litter, mineral soil,rock, and each individual species was estimated,Forty penetration resistance readings were takensystematically throughout the control plot.

The campsite and control center points weremarked with buried nails, as were the endpoints ofthe perimeter transects. This permitted the preciserelocation of all measurement units. On two sitesonly a few measurements could be taken, both in1984 and 1989.

The sites reexamined in 1990 after 6 years-were not different from those reexamined in 1989;so for ease of discussion, the text will be written asif all sites were reexamined in 1989, after 5 years.Data analysis and presentation is similar to that forthe other case studies, except that changes on camp-site cores and perimeters are reported separately.

Changes on All SitesTrends on Campsite Cores -Conditions on

campsite cores were relatively unchanged over the5 years. The only statistically significant changewas a mean increase in vegetation cover of 5 percent(table 10). Although statistically significant, vegeta-tion cover did not increase substantially on manysites. Vegetation cover on the median site did notchange; even on the 10 sites that did increase incover, the median increase was only 4 percent.However, three sites did experience substantial in-creases in cover; all of these were low-use sites withno evidence of recent use. Cover on one of thesesites increased from 10 percent in 1984 to 62 percentin 1989. Substantial decreases in cover on campsitecores were impossible, by definition.

Although there were no significant trends for theother types of impact, this does not mean that condi-tions were unchanged on individual sites. Meancore area was virtually unchanged over the 5 years,but 16 sites changed in size by more than 10 per-cent. Nine of these changes were decreases andseven were increases. The largest change was a38-m2 increase in size. These results suggest thatthere have been substantial changes on individualsites, but no clear overall tendency for cores to eitherincrease or decrease in size.

Changes in the cover of organic litter on cores par-allel changes in vegetation (fig. 15). Litter covergenerally increased; on all but a few sites, changeswere subtle. Litter increased on more sites than itdecreased. Mean litter cover increased from 5 per-cent in 1984 to 9 percent in 1989; however, cover on

Table 10 -Mean changes on the awe of all 24 campsites, 1Grand Canyon National Park

Core Vegetation Organic litter PenetrationStatistic area cover cover resistance

m2 - - - - - - - p e r c e n t - - - - - - kg/cm2

Conditions1984 51 1 5 2.71989 50 7 9 2.1

ChangeAbsolute -1 5 4 -0.6Relative (percent) -2 500 80 -22

Number of sitesIncrease 9 10 10 10Decrease 14 3 5 13Unchanged 1 11 9 1

Significance 0.46 0.04 0.08 0.09*

the median site was unchanged. Increases weretypically larger than decreases. The median in-crease on sites that increased was 4 percent, whilethe median decrease was 2 percent. On one site,however, litter cover increased from 5 percent in1984 to 44 percent in 1989.

Penetration resistance values tended to decline,although the decline was not statistically signifi-cant. This indicator of soil compaction decreasedon 13 sites and increased on 10 sites. Declines in

Campsite Cores

1984

1990

Perimeters

1984

1990

Control Sites

1984

1990

Figure 15- Mean coverage of ground covercategories on campsites and control sites in1984 and in 1989, Grand Canyon National Park.

penetration resistance were also more common thanincreases on controls (table 11). This suggests thatpenetration resistance values, which vary with soilmoisture, generally tended to be lower in 1989 thanin 1984. On the median site, the absolute differencebetween campsite and control values was the samein 1989 as it was in 1984. This strongly suggeststhat there has been no overall change in the levelof soil compaction over this period.

Overall, conditions on the core of most campsiteswere relatively stable. Where change did occur, de-terioration was more common than improvement,but the magnitude of improvement was greater thanthe magnitude of deterioration. Because cores weredefined as areas without vegetation, substantial de-terioration was unlikely to occur on cores. The ma-jor type of deterioration that could occur was enlarge-ment of the core over time. Five sites experiencedsubstantial increases in core area (increases of atleast 10 m2, or 20 percent). These sites were varied,including both high-use and low-use sites and allthree vegetation types. The most dramatic changes,however, were substantial improvements on threesites-increases in vegetation and organic litter anddecreases in core area. All three of these sites arelow-use catclaw sites that appear to have been un-used over the study period.

Trends on Campsite Perimeters-Overalltrends are not pronounced on campsite perimeters(tables 11 and 12), and deteriorating conditions aremore common than improving conditions. Threetypes of impact deteriorated consistently enoughto be statistically significant, although in one casesimilar changes on the control suggest that thechange is not a result of camping.

Table 11 -Mean changes in penetration resistance and shrub density on the perimeter andcontrol of all 24 campsites, 1Grand Canyon National Park

StatisticPenetration resistance Shrub density

Perimeter Control Perimeter Control

Conditions19841989


Number of sitesIncreaseDecrease

Table 12 -Mean changes in ground cover conditions on the perimeter and control of all 24 campsites, 1Grand Canyon NationalPark

Vegetation Cryptogam Litter Mineral Rock

Statisticcover cover cover soil cover cover

Perimeter Control Perimeter Control Perimeter Control Perimeter Control Perimeter Control------------------------------------------------------------------------------------------------- Percent-------------------------------------

Conditions1984 52 61 5 9 53 61 25 24 8 71989 47 62 3 6 52 62 30 24 7 6

ChangeAbsolute -5 1 -1 -4 -1 2 4 -1 -1 0Relative (percent) -10 1 -20 -44 -2 3 16 -4 -13 0

Number of sitesIncrease 6 4 5 5 9 4 13 2 3 0Decrease 15 3 11 8 12 3 9 3 13 4Unchanged 2 16 7 10 2 16 1 18 7 19

Significance 0.01* 0.30 0.20 0.08 0.72 0.87 0.04* 0.89 0.09* 0.09'Absolute change is the condition in 1989 minus the condition in 1984. Relative change is absolute change as a percentage of the condition in

1984. Significance was tested with the Wilcoxon matched-pairs, signed-ranks test, or with the paired t-test where denoted with an * .

Shrub density decreased on 15 of 22 campsiteperimeters and on 15 of 22 controls (table .11). Themean change was a 23 percent decrease in densityon perimeters and a 14 percent decrease on controls.In 1984, shrub density, surprisingly, was greater oncampsite perimeters than on controls. This appearedto result from a large number of small individuals,particularly of Gutierrezia sarothrae (broom snake-weed), on perimeters. During the 5 years between1984 and 1989, a number of individuals disappeared,both on perimeters and controls. In 1989, perim-eters and controls were more similar than they werein 1984-perhaps as a result of smaller individualsnot surviving the generally droughty conditions.

In contrast to the increase in vegetation on cores,vegetation cover decreased significantly on perim-eters (table 12). Mean vegetation cover decreasedfrom 52 percent in 1984 to 47 percent in 1989 (fig. 15).Vegetation cover decreased on the perimeter of 15sites and increased on six sites. The median de-crease on the sites that decreased was 8 percent; onone site vegetation cover decreased from 58 percentin 1984 to only 33 percent in 1989. Increases weresmaller; the largest increase was only 8 percent.Vegetation cover was relatively stable on controls,suggesting that these decreases on perimeters resultfrom camping impacts.

This loss of vegetation corresponds with less pro-nounced and nonsignificant decreases in the coverof cryptogams and litter, as well as a significant in-crease in mineral soil exposure (table 12). Mineralsoil cover increased on 13 of 23 sites. The median

on nine sites, but decreases were generally small(median decrease of 1 percent).

As on campsite cores, penetration resistance val-ues increased and decreased-in approximatelyequal numbers. There is no evidence of any signifi-cant overall trend in the level of soil compaction.

Overall, the perimeters of most sites are relativelystable; changes on most sites were small. More sitesare deteriorating than improving. Eight sites showevidence of substantial deterioration along theirperimeter-loss of vegetation and organic litter andan increase in soil exposure. Six of these eight sitesare high-use sites. The two low-use sites that aredeteriorating are in an area that appears to haveincreased in popularity.

Vegetation Changes - The most common speciesgrowing on cores in 1984 were two nonnative annu-als, Bromus rubens (red brome) and Erodium cicu-tarium (filaree), and the native shrub Gutierreziasarothrae. These were still the most common spe-cies on cores in 1989, although the number of speciesfound on cores had increased by 1989. Species foundon several cores in 1989 include Sporobolus crypt-andrus (sand dropseed), Ephedra nevadensis (Nevadajoint-fir), Calochortus flexuosus (straggling mariposa),and Cryptantha sp. (hiddenflower).

In 1984 the species composition of campsite perim-eters was not greatly different from the compositionof controls. The mean floristic dissimilarity betweenperimeters and controls was only 31 percent. Thiswas less than the difference typical of two undis-turbed stands in the same vegetation type.

and was statistically significant. Increasing dissim-ilarity can result from either changes on campsites,changes on controls, or both. To investigate further,we calculated the floristic dissimilarity betweenyears for perimeters and for controls. The mean dis-similarity on perimeters between 1984 and 1989 was25 percent, while the mean difference on controlswas 31 percent. The change in species compositionon controls was greater than that on perimeters on14 of the 18 sites that experienced increases in dif-ference between campsite and control. These datasuggest that both campsites and controls changedbetween 1984 and 1989, with the greater changestending to occur on the controls.

Species richness declined on both campsite perim-eters and controls. On perimeters the mean numberof vascular plant species decreased from 19 in 1984to 17 in 1989. Fifteen of 22 sites experienced a de-crease in species richness; the median loss was threespecies. The seven species that were most frequentlyabsent from sites where they were found in 1984were annuals. Two were grasses, Vulpia octoflora(six-weeks fescue) and Poa bigelovii (Bigelow’s blue-grass); five were forbs, Plantago purshii (Indianwheat), Descurainia pinnata (yellow tansy mustard),Astragalus nuttallianus (Nuttall locoweed), Giliaflavocincta (thread-stemmed gilia), and Lepidiumlasiocarpum (sand peppergrass). The only speciesfound much more frequently in 1989 was Calochor-tus flexuosus.

Species richness also declined on 18 of the 22 con-trols. This, along with the fact that species composi-tion changed as much on controls as on campsites,suggests that these changes result from changes inthe natural environment, rather than from camping.As on campsites, the most common species to beabsent from controls were annuals. This suggests

Table 13 -Mean relative cover of growth forms and of nonnative species on the perimeterand control of all 24 campsites, Grand Canyon National Park

Perimeters ControlsStatistic 1984 1989 1964 1989

Shrubs-trees’ 55 68 53 68Cacti ‹1 ‹1 1 1Shrubs’ 40 49 35 48Trees* 15 19 17 19

Grasses-total’ 32 23 34 24Annuals’ 28 16 28 18Perennials* 4 7 6 6

Forbs-total 4 4 6 4Annuals 2 1 3 1Perennials* 2 3 3 3

that the major factor accounting for change in spe-cies composition was the severe drought conditionin 1989.

Changes in species composition were further ex-plored by calculating the mean relative cover of eachgrowth form and of nonnative species. These rela-tive covers are displayed for both years and forcampsite perimeters and controls (table 13). Themost pronounced shifts between 1984 and 1989were an increase in the relative cover of shrubs anda decrease in the relative cover of annual grasses.Bromus rubens, a nonnative annual grass, contrib-uted 26 percent of the total cover on campsite pe-rimeters in 1984; in 1989 it contributed only 14 per-cent. Consequently, the cover of nonnative specieswas substantially lower in 1989. Similar changesoccurred on controls, reinforcing the notion thatchanges in vegetation composition are a response tonatural environmental changes, such as the amountand distribution of precipitation, rather than camping.

In 1984 the only growth forms that differed signifi-cantly, in relative cover, between perimeters andcontrols were shrubs and total forbs. Shrubs wererelatively more abundant on campsites, and forbswere relatively less abundant on campsites. In 1989there were no significant differences in the relativecover of different growth forms. Changes in the fre-quency and cover of individual species are listed inappendix 3.

Overall Trends -To assess overall impact, asummary impact rating was calculated for each site.Impact indicators used in this summary rating were:core area, vegetation cover on the core, organic littercover on the core, relative difference in vegetationcover on perimeters, and absolute difference in min-eral soil exposure on perimeters. For each of these

indicators, campsites were assigned a rating of 1,2,or 3 (low to high amount of impact). The impactrating is the mean of the five indicators.

The mean impact rating was 2.0 in 1984 and 2.1in 1989. This change was not statistically signifi-cant. Sixteen of the sites were relatively stable (im-pact ratings changed no more than 0.2). Impact rat-ings increased by more than 0.2 on five sites anddecreased by more than 0.2 on three sites. The fivesites that deteriorated include both high-use andlow-use sites and were located in all vegetationtypes but pinyon-juniper. The three sites that im-proved were all low-use catclaw sites that appearto have been unused over the 5 years. Only twosites changed substantially (changes of more than0.4); one improved and one deteriorated

Factors That Influence Amount ofChange

Amount of Use- In 1984, high-use sites differedsignificantly from low-use sites in several ways.High-use sites had larger core areas, less vegetationand organic litter on the core, and higher penetra-tion resistance readings on the core (table 14). Noneof the impacts on the campsite perimeter that wereremeasured in 1989 differed between high-use andlow-use sites in 1984. Bulk density and soil mois-ture were higher on the perimeter of high-use sitesin 1984 but were not remeasured in 1989.

All four of the differences between high-use andlow-use sites that were significant in 1984 were alsosignificant in 1989 (table 14). Moreover, the magni-tude of difference between high-use and low-usesites increased. Mean vegetation cover increased by2 percent on high-use cores, from 0 percent in 1984to 2 percent in 1989. Mean vegetation cover in-creased by 8 percent on low-use cores, from 3 to 11percent. Mean litter cover increased by 1 percent onhigh-use cores and by 6 percent on low-use cores.Mean penetration resistance on high-use cores de-clined from 3.8 kg/cm2 in 1984 to 3.4 kg/cm2 in 1989;means on low-use cores declined from 1.6 kg/cm2 to0.9 kg/cm2. Core areas were virtually unchanged onboth sets of sites, but the area of low-use cores diddecrease slightly. All of these changes in the magni-tude of difference between high-use and low-usesites are relatively small. For none of these is therea statistically significant difference between high-use and low-use sites in the amount of change be-tween 1984 and 1989.

The only site characteristics for which amount ofchange differed significantly between high-use andlow-use sites were the mineral soil and litter coveron campsite perimeters (table 151. The mean changein mineral soil exposure on high-use sites was an in-crease of 9 percent; on low-use sites there was nochange. In 1989, high-use perimeters had 10 per-cent more soil exposure than controls; low-use pe-rimeters had just 2 percent more soil exposure than

Table 14 -Mean change in conditions on the core of 12 high-use and 12 low-use campsites, 1Grand Canyon National Park

S t a t i s t i cAmount of use

High Low Significance

Core area (m2)19841989Change


Litter cover (percent)19841989Change

Penetration resistance (kg/cm*)19841989Change

6767

0

3434-1

311

9

915

6

0.001.OOl.75

.02

.02

.74

Table 15 -Mean change in conditions on the perimeter of 12 high-use and 12low-use campsites, 1Grand Canyon National Park

StatisticAmount of use

High Low Significance


Cryptogam cover (percent)19841989Change


Mineral soil cover (percent)19841989Change

Shrub density (No./m2)19841989Change

Penetration resistance (kg/cm*)19941989Change

54 49 0.27*51 44 .21*-4 -5 .64*

3 6 .122 5 .46

-1 -2 .66

56 51 .28*49 55 .27*-6 5 .001*’

22 28 .4131 28 .3*’

9 0 .001*’

1.34 1.47 .39.85 1.31 .10

-0.49 -0.17 .32

1.1 0.9 .17*1.5 0.6 .0010.4 -0.3 .08*

1Change is the condition in 1989 minus the condition in 1984. Significance wastested with the Mann-Whitney U, or with t -test where denoted with an * . Tests for 1984and 1989 are one-tailed; tests for change are two-tailed.

controls. This greater amount of impact on high-usesites is statistically significant. It suggests that in-creased mineral soil exposure on perimeters is animpact that is already more pronounced on high-usesites and becoming more pronounced on those sitesas time passes.

The mean change in litter cover on high-use siteswas a decrease of 6 percent; the mean change onlow-use sites was an increase of 5 percent. The de-crease on high-use sites is significant, as is the in-crease on low-use sites. Nevertheless, differencesin the amount of litter cover on high-use and low-usesites in 1989 are not significant. However, if thetrend of greater deterioration on high-use sites con-tinues differences will become substantial in thefuture.

Penetration resistance on high-use and low-usecampsite perimeters in 1984 were not significantlydifferent. Resistance tended to increase on high-use

Vegetative conditions and vegetation impact oncampsite perimeters did not differ significantly be-tween high-use and low-use sites. Cover declinedon both types of sites, as is reflected in the signifi-cant overall decline in vegetation cover on the pe-rimeter (table 12). Floristic dissimilarity increasedand species richness decreased on both high-use andlow-use sites. The only significant difference in spe-cies composition in 1989 was a greater relative coverof shrubs on low-use sites than on high-use sites.Shrub cover on high-use and low-use sites had notbeen significantly different in 1984; in 1989, meanshrub cover was 29 percent on low-use sites and 22percent on high-use sites. Although vegetative coveris being lost on the perimeter of both high-use andlow-use sites, the high-use sites are experiencing amore pronounced loss of shrubs. This may have se-rious long-term implications because recovery ofshrub clumps takes such a long time (Wallace and

sites and decrease on low-use sites, although this

difference in response was not significant. Never-

theless, in 1989, soil compaction on campsite perim-eters was significantly greater on high-use sites.

others 1980). Mean impact ratings in 1984 were 1.73 on low-use

sites and 2.38 on high use sites. The difference wasstatistically significant. Between 184 and 1989,

ratings on low-use sites declined slightly to 1.68,while they increased slightly on high-use sites-to2.47. Although the amount of change did not differsignificantly between high-use and low-use sites, themagnitude of difference increased over the 5 years.

Overall, several conclusions can be drawn abouthigh-use and low-use sites. High-use sites continueto be more highly impacted than low-use sites. Forvirtually all types of impact, the magnitude of differ-ence between high-use and low-use sites increasedbetween 1984 and 1989. Typically, this results from(1) greater improvement on the core of low-use sitesand (2) greater deterioration on the perimeter ofhigh-use sites. Core conditions differ more betweenhigh-use and low-use sites than perimeter condi-tions do. However, the significant differences inamount of change between 1984 and 1989 resultfrom higher levels of deterioration around the pe-rimeter of high-use sites.

Differences Among Vegetation Types -In1984 there was only one significant difference amongvegetation types in impact on cores. Pinyon-junipercores were several times as large as sites in theother types. Core area did not change substantiallybetween 1984 and 1989 on sites in any of the threevegetation types (table 16).

By 1989, campsites had changed to the pointwhere conditions other than core area differed be-tween vegetation types. In 1989, catclaw cores hadsignificantly more vegetation than sites in the othertypes (table 16). Catclaw and desert scrub cores had

significantly more litter cover than pinyon-junipersites. For both vegetation and litter, the core ofcatclaw sites improved substantially while sites inthe other two vegetation types changed little overthe 5 years. The three sites with the largest in-creases in vegetation cover on cores were low-usecatclaw sites with no evidence of recent use. Coveron these sites increased from 2,5, and 10 percent in1984 to 26,29, and 62 percent, respectively, in 1989.This shows that, in the absence of use, lightly im-pacted catclaw sites are capable of substantial recov-ery in just 5 years. In contrast, on two unused pinyon-juniper sites, vegetation cover increased 1 percent inone case and was unchanged in the other.

Vegetation, litter, and mineral soil cover on perim-eters differed among vegetation types in 1984.Pinyon-juniper sites have relatively low vegetationand litter cover and relatively high mineral soilcover. However, these differences, which were alsosignificant in 1989, merely reflect conditions on con-trols. There were no significant differences amongvegetation types in either the absolute or relativedifference between campsite perimeters and con-trols.

For these three ground cover characteristics thereare also no significant differences in amount ofchange between 1984 and 1989 (table 17). The in-crease in mineral soil cover that characterizes theoverall trend on campsite perimeters occurs on sitesin all three vegetation types. The loss of vegetationcover on perimeters is substantially more pronouncedon desert scrub sites, although this difference is not

Table 16 -Mean change in conditions on the core of eight campsites in each of threevegetation types, 1Grand Canyon National Park

Pinyon-Statistic juniper

Core area (m2)1984 821989 82Change 0

Vegetation cover (percent)1984 01989 0Change 0

Litter cover (percent)1984 11989 1Change 0

Penetration resistance (kg/cm2)1984 2.61989 2.6Change 0

Vegetation type

Catclaw

3431-3

21614

21412

2.52.0

-0.5

Desertscrub

3637

1

231

1211-1

3.01.9

-1.2

Significance

0.04.04.48

52.02.06

.22

.04

.06

.81*

.74

.37*

‘Change is the condition in 1989 minus the condition in 1984. Significance was tested with Kruskal-Wallis, or with parametric one-way analysis of variance tests where denoted with an * .

28

Table 17- Mean change in conditions on the perimeter of eight campsites in each of threevegetation types,1 Grand Canyon National Park

Statistic

Vegetation typePinyon- Desertjuniper Catclaw scrub Significance


Cryptogam cover (percent)19841989Change


Mineral soil cover (percent)19841989Change

Shrub density (No./m2)19841989Change

Penetration resistance (kg/cm2)19841989Change

33 68 55 0.001*32 64 45 .OO1* -1 -4 -10 .07*

9 .062 .06

-7 .O1

551

231

30 74 55 .OO1*29 72 57 .OO1*-1 -2 2 .75*

52 7 16 .O0154 11 23 .OO1*

2 4 7 .57

1.02 1.72 1.53 .790.96 1.33 0.98 .65

-0.06 -0.39 -0.55 .34

0.6 1.0 1.4 .04*0.9 1.0 1.1 .830.3 0.1 -0.2 .51*

1Change is the condition in 1989 minus the condition in 1984. Significance was tested with Kruskal-Wallis, or with parametric one-way analysis of variance tests where denoted with an * .

quite significant. However, the increase in both ab-solute and relative difference between perimetersand controls is significantly greater on desert scrubsites. Changes in several other vegetation charac-teristics also suggest that more deterioration oc-curred on the perimeter of desert scrub sites. Thedecrease in cryptogam cover between 1984 and 1989was significantly greater on desert scrub sites. Theincrease in floristic dissimilarity between perimetersand controls is also significantly greater on desertscrub sites.

Neither shrub density nor penetration resistancediffered significantly between vegetation types in1989. Amount of change did not differ either. Pen-etration resistance differed between vegetation typesin 1984, but this difference disappeared by 1989.

Overall, pinyon-juniper sites continue to be sub-stantially larger than sites in the other types. Theynaturally have less vegetation and organic matterand more exposed mineral soil. For the most partthey are relatively stable. Core conditions do notchange dramatically on pinyon-juniper sites, evenwhen camping use is discontinued. One of the high-use designated sites on Horseshoe Mesa was closed

shortly after our 1984 measurements were taken.It appears that this site has not been used since, butchange has been negligible. Perimeters of pinyon-juniper sites are not highly subject to impact in partbecause the large core area provides sufficient roomfor campers to spread out.

The core of sites in the other vegetation types isalso relatively stable when subjected to continuedregular camping use. But the catclaw sites-at leastthe ones that were never severely impacted-appearcapable of relatively rapid revegetation when camp-ing use stops. The response of desert scrub sites,once camping is eliminated, is unclear because usecontinued on all sites.

There is also some evidence to suggest that theslight deterioration that characterizes the overalltrend on campsite perimeters was most pronouncedon the desert scrub sites. Four of the five sites withthe largest declines in vegetation cover on the pe-rimeter were desert scrub sites. The largest changeswere on lightly used sites in areas that have recentlyincreased in popularity.

Mean impact ratings in 1984 were 2.33 on pinyon-juniper sites, 2.06 on catclaw sites, and 1.84 on

29

desert scrub sites. These differences were not statis-tically significant. Between 1984 and 1989, ratingsdeclined 0.03 on pinyon-juniper sites and 0.15 oncatclaw sites; they increased 0.26 on the desertscrub sites. The increase in impact between 1984and 1989 on desert scrub sites was significantly dif-ferent from the decrease in impact on catclaw sites.

The minimal change in mean impact on pinyon-juniper sites accurately reflects the general stabilityof those sites. None of these sites changed substan-tially. Similarly, most desert scrub sites deterio-rated and the mean change in rating is positive.The mean value for catclaw sites is more deceptive.Several of the catclaw sites improved greatly; hence,the mean decline in impact ratings. But a numberof the catclaw sites deteriorated as greatly as thedesert scrub sites. The greater tendency for catclawor desert scrub sites to deteriorate probably resultsfrom their small size. The natural tendency forcampers to spread out is constrained on these sitesby the rough terrain and the tough and spiny veg-etation. It appears that, over time, these sites willexpand slowly to provide more space for campers.The pinyon-juniper sites are already large enoughfor campers, so little further change is occurring.

Earlier Conditions- We examined the relation-ship between amount of change between 1984 and1989 and the condition of the campsite in 1984. Nocorrelation was found. When we considered onlyhigh-use sites, however, we found a significant cor-relation between amount of change and the priorcondition of the site (Kendall’s tau = 0.45; p = 0.03).The high-use sites that were less impacted in 1984were more likely to have deteriorated substantiallyby 1989 than those that were more highly impacted.This corroborates the similar result on Eagle Capcampsites. There was no similar correlation on low-use sites.

Conclus ions

The principal conclusions to be drawn from thisstudy of 5 years of change on Grand Canyon camp-sites are:

1. The general trend on established campsites,particularly those that continue to be used, is one ofslight deterioration. Most sites are relatively stable,however.

2. Trend varied with type of impact and betweencampsite cores and campsite perimeters. The cores,which were already severely impacted in 1984, gen-erally did not change much. Vegetation and organiclitter cover increased slightly on many campsitecores, suggesting some improvement in conditions.In contrast, conditions deteriorated on the perim-eters of most sites. Vegetation cover and organic

litter cover declined, and mineral soil exposureincreased.

3. Differences in amount of impact between low-use and high-use sites are increasing with time(fig. 16). This results primarily from more pro-nounced improvements on the cores of low-use sitesand more pronounced deterioration on the perim-eters of high-use sites. But responses of individualsites vary from this typical response. Low-use coresare more likely to have deteriorated or improvedsubstantially than high-use cores.

4. Although high-use sites are more highly im-pacted than low-use sites, differences in amount ofimpact are not as great as differences in the amountof use these sites receive. Sites that receive an orderof magnitude more use typically are no more thanseveral times as highly impacted.

5. Change in campsite condition varied betweensites in different vegetation types. Virtually all ofthe pinyon-juniper sites were relatively stable, eventhose that appeared to have been unused over the5 years. This can be accounted for by the unusualsize of these sites in 1984, the high level of impactthat already existed in 1984, and the harsh, xericconditions on these sites. In contrast, the catclawsites-located in the most mesic places-are capableof surprisingly rapid recovery, once camping ceases.Where high-use continues, however, the catclawsites, along with the desert scrub sites, oftendeteriorated over the period.

Figure 16- Change in overall impact rating between 1984and 1989 on low-use and high-use Grand Canyoncampsites.

30

DISCUSSION AND MANAGEMENTIMPLICATIONS

Not surprisingly, there is no simple answer to thequestion, “How are wilderness campsites changingover time?” As these case studies show, certaincampsites are getting better, while others are get-ting worse, and many are relatively stable. More-over, on a single campsite, certain types of impactmay be getting worse, while other types are improv-ing. On the Grand Canyon sites, we even had situa-tions where vegetation cover was increasing on thecampsite core and decreasing on the campsiteperimeter.

In all three areas, most sites were relatively stableoverall. In the Eagle Cap and Grand Canyon, thenumber of sites that deteriorated exceeded the num-ber that improved. In the Bob Marshall, the oppo-site was the case; however, as noted in the previousdiscussion, if only recently used sites are considered,deteriorated sites outnumbered improved sites hereas well. This suggests, to the extent that these casestudies are representative, that the overall trend onestablished sites is one of slight deterioration overtime.

Trends vary between types of impact, however.The most consistent increase in impact is continuedenlargement of sites over time. Camp area tendedto increase on Eagle Cap and Bob Marshall camp-sites. Although not measured on Grand Canyoncampsites, the deterioration of campsite perimetersthere suggests a slow expansion of sites. Merriamand others (1973), in their study of changes onBoundary Waters Canoe Area campsites, found thatcampsite expansion was the most prominent changethat followed initial use of campsites.

Other types of impact that often deteriorated weremineral soil exposure and tree damage, particularlyexposure of tree roots. Mineral soil exposure tendedto increase on sites in the Eagle Cap and GrandCanyon, although it was unchanged on Bob Marshallsites. Potential reasons for the lack of increased soilexposure on Bob Marshall sites include relativelythick organic horizons and low use levels. Sites withthick organic horizons are less vulnerable to mineralsoil exposure than sites with thin organic horizons.Particularly where organic horizons are thick, expo-sure may occur only where trampling disturbance ispronounced (Cole 1987a).

Increased tree root exposure was documented onlyon the Eagle Cap sites. On Bob Marshall sites, in-creased root exposure was observed in places wherestock was kept, but the extent of increase was notquantified. Tree damage of all types is cumulative.Damage to new trees is not offset by recovery ofother trees. Therefore, as long as any new damage

occurs, the overall trend in tree damage is towarddeterioration.

In contrast to soil exposure and tree damage, im-pacts to ground cover vegetation declined or wererelatively stable in all three areas. The size ofdevegetated core areas decreased, and the amountof vegetation cover and number of tree seedlings in-creased. There was also little evidence of change inspecies composition except for the increase in nonna-tive vegetation on Bob Marshall sites. Apparently,these types of impact equilibrate quickly to a givenlevel of camping intensity.

In another study in the Boundary Waters CanoeArea on campsites of widely differing ages, oldercampsites (those more than 13 years old) had sub-stantially higher levels of tree damage and mineralsoil exposure but comparable levels of vegetation im-pact (Cole and Marion 1986). This tends to supportthe findings of the current study. Campsite areawas not significantly greater on the older BoundaryWaters sites. However, this may reflect the imposi-tion of a party size limit of 10 and a campsite main-tenance program that actively attempts to limitexpansion.

In some way or another, each of these areas wasunique in terms of the types of impact that occurred.Exotic species were a problem on Bob Marshall andGrand Canyon sites but not on the subalpine sites inthe Eagle Cap. Bob Marshall sites are characterizedby extremely severe tree damage-an impact thatrarely occurs in the Grand Canyon. On Eagle Capsites, increases in mineral soil exposure are particu-larly pronounced. These differences suggest that itis important to tailor indicators and monitoring pro-cedures to each area.

In the two studies that compared changes on low-use and high-use sites, high-use sites were generallymore highly impacted, and the magnitude of differ-ence increased over the study period. With few ex-ceptions, high-use sites either deteriorated or wererelatively stable. In contrast, certain low-use sitesdeteriorated as much as the high-use sites, whileothers improved substantially. This variability inresponse is at least as much a distinguishing charac-teristic of low-use sites as their lower impact levels.

As reported in earlier studies, the relationship be-tween amount of use and amount of impact is curvi-linear (Cole 1982). High-use sites may be morehighly impacted than low-use sites, but differencesin amount of use are much greater than differencesin amount of impact.

The earlier finding that lightly impacted sites aremore likely to deteriorate over time than heavily im-pacted sites (Cole 1986a) was only partially sup-ported by these results. When comparing sites thatreceive similar amounts and types of use, this

31

relationship may apply. However, more definitiveresearch is needed. If this relationship is generallyfound, it would suggest that campsite conditions arebecoming more homogeneous over time.

In all three studies, we were able to examinechange on sites that were no longer being used.Changes on these sites were highly variable. Insome cases they deteriorated further despite beingvirtually unused. In other cases, sites recovered somuch that it was difficult to find them. This vari-ability in response appears to be influenced by bothprevious use/impact levels and environmental char-acteristics. Generally, high-impact/high-use sitesrecover slowly. For example, a decade of closure onthe high-use Eagle Cap sites has resulted in mini-mal improvement. In contrast, sites that have notbeen highly impacted are likely to recover more rap-idly when use ceases. For example, in Grand Can-yon, three low-use catclaw sites that were no longerin use experienced pronounced increases in vegeta-tion cover.

Environmental conditions are also important. Themost dramatic recovery occurred in the Bob Marshallon a high-use outfitter site that was closed to use.This site was difficult to find less than 10 years afterit was closed. Rapid recovery probably resulted froma combination of a long growing season, fertile andwell-watered soils, and an abundance of nonnativespecies adapted to recolonizing disturbed sites. Inthe Grand Canyon, relatively mesic catclaw sitesrecovered relatively rapidly, while unused xericpinyon-juniper sites changed slowly.

The two conclusions of this study-that estab-lished sites tend to deteriorate slowly and thatclosed sites recover at variable rates-can be addedto previous work on changes following the initialestablishment of sites to suggest a typical campsite“life history” (fig. 17). As a campsite first develops,deterioration is rapid, often reaching near-maximumlevels after a few years of use (Merriam and others1973). This “development” phase is followed by amore stable phase during which deterioration con-tinues but at a much slower rate. Campsite expan-sion, tree damage, and mineral soil exposure appearto be the impacts that tend to become accentuatedduring this phase. If the site is effectively closed touse, recovery will occur. The rate of recovery is vari-able but always slower than the rate of deteriora-tion. Recovery will occur more rapidly where grow-ing conditions are more favorable and on sites thatwere not severely impacted. Management can speedrecovery by ameliorating growing conditions andhelping with the recolonization process.

The results of these studies give little reason to beeither optimistic or pessimistic about the future con-dition of established campsites. There is little

Low-resilienceenvironment

Time

Figure 17- The “life history” of a typical campsite.

evidence to suggest that established campsites aremuch worse than they were a decade ago. Manywilderness campsites have been severely impactedfor decades. Continued use of these sites may causefurther deterioration, but at rates that are low whencompared with the impact that has already occurred.

On the other hand, some have suggested that ap-parent declines in wilderness use, shifts toward wil-derness activities that have lower impact, and in-creasing visitor knowledge about low-impact campingtechniques might be reflected in a reduction in prob-lems (Lucas 1989). These results suggest that thereis little evidence that campsite deterioration problemsare declining.

The reader should remember that this study onlydescribes change on established campsites. Camp-site impact, in any area, is a function of both thenumber of sites and the condition of those sites. Ifthe number of campsites increases greatly, campsiteimpact problems will increase greatly, even if theoriginal sites are relatively unchanged. Change innumber of campsites is the subject of another reportin preparation.

Changes in condition-either improvement ordeterioration-are most likely to occur on low-usesites and in lightly used places. This suggests thatthese sites and places should be given higher prior-ity by management because this is where “good”management can be most beneficial. On frequentlyused established campsites, management should fo-cus on avoiding increases in site area and tree dam-age. Actions that can be effective include user edu-cation, party size limits, and active rehabilitationand maintenance of campsite perimeters (Cole 1986a).

32

METHODOLOGICAL PROBLEMS ANDIMPLICATIONS

Several methodological problems became apparentwhen sites were reinventoried. The most significantproblem was the inability to precisely documentoffsite impacts. This shortcoming was most seriouson the Bob Marshall sites where impacts in stock-holding areas were often more substantial thanthose occurring on the campsite proper. Offsite treedamage also had to be ignored on Eagle Cap camp-sites. Unfortunately, we do not have any practicalsuggestions for how to monitor these impacts. Theyhave a tendency to shift around over time. Monitor-ing plots can be established where offsite impactsare most pronounced. However, when the site is re-examined, use might have shifted to a place outsideof this monitoring plot.

Even on the campsite proper, use can shift enoughto cause problems. On several Bob Marshall sites,the devegetated central core in 1981 had recoveredsubstantially, while a newly devegetated area haddeveloped a short distance away. But this is rare.

A final limitation was the effect of the smallsample size on the power of statistical tests. Samplesizes were small because of the time required to ob-tain detailed, careful measurements. Over the in-tervening years, sample sizes tended to decline dueto changes on sites such as managers closing sitesor visitors no longer choosing to use a site. Moredefinitive conclusions could be drawn if sample sizeswere larger.

On the positive side, the methods used were suffi-cient to deal with the problems of year-to-year andseasonal changes in environmental conditions. Sub-stantial temporal variation was apparent on sites inboth the Bob Marshall and the Grand Canyon. Byfollowing changes on control plots, it was possible toseparate changes in environmental conditions fromchanges caused by camping.

Finally, these results suggest that lightly im-pacted sites are more likely to change than heavilyimpacted sites and that most established siteschange relatively slowly. This argues against thewisdom of monitoring heavily impacted sites fre-quently. It also suggests that there is little value inmonitoring established sites more frequently than,perhaps, once every 5 years. Frequent monitoringis needed most where conditions are relatively un-disturbed and there is reason to think that amountof use has increased or the type of use is shifting to-ward a type with more potential to cause impact.

REFERENCES

Cole, David N. 1978. Estimating the susceptibility ofwildland vegetation to trailside alteration. Journalof Applied Ecology. 15: 281-286.

Cole, David N. 1982. Wilderness campsite impacts:effect of amount of use. Res. Pap. INT-284. Ogden,UT: U.S. Department of Agriculture, Forest Ser-vice, Intermountain Forest and Range ExperimentStation. 42 p.

Cole, David N. 1983a. Campsite conditions in theBob Marshall Wilderness, Montana. Res. Pap.INT-312. Ogden, UT: U.S. Department of Agricul-ture, Forest Service, Intermountain Forest andRange Experiment Station. 18 p.

Cole, David N. 1983b. Monitoring the condition ofwilderness campsites. Res. Pap. INT-302. Ogden,UT: U.S. Department of Agriculture, Forest Ser-vice, Intermountain Forest and Range ExperimentStation. 10 p.

Cole, David N. 1986a. Ecological changes on camp-sites in the Eagle Cap Wilderness, 1979 to 1984.Res. Pap. INT-368. Ogden, UT: U.S. Departmentof Agriculture, Forest Service, Intermountain Re-search Station. 15 p.

Cole, David N. 1986b. Recreational impacts onbackcountry campsites in Grand Canyon NationalPark, Arizona, USA Environmental Management.10: 651-659.

Cole, David N. 1987a. Effects of three seasons of ex-perimental trampling on five montane forest com-munities and a grassland in western Montana,USA Biological Conservation. 40: 219-244.

Cole, David N. 1987b. Research on soil and vegeta-tion in wilderness: a state-of-knowledge review. In:Lucas, Robert C., compiler. Proceedings-nationalwilderness research conference: issues, state-of-knowledge, future directions; 1985 July 23-26;Fort Collins, CO. Gen. Tech. Rep. INT-220. Ogden,UT: U.S. Department of Agriculture, Forest Ser-vice, Intermountain Research Station: 135-177.

Cole, David N.; Marion, Jeffrey L. 1986. Wildernesscampsite impacts: changes over time. In: Lucas,Robert C., compiler. Proceedings-national wilder-ness research conference: current research; 1985July 23-26; Fort Collins, CO. Gen. Tech. Rep.INT-212. Ogden, UT: U.S. Department of Agricul-ture, Forest Service, Intermountain Research Sta-tion: 144-151.

Lucas, Robert C. 1989. A look at wilderness use andusers in transition. Natural Resources Journal.29:41-56.

33

Merriam, L. C.; Peterson, R. F. 1983. Impact of 15years of use on some campsites in the BoundaryWaters Canoe Area. Res. Note 282. St. Paul, MN:University of Minnesota, Agricultural ExperimentStation. 3 p.

Merriam, L. C., Jr.; Smith, C. K.; Miller, D. E.; [andothers]. 1973. Newly developed campsites in theBoundary Waters Canoe Area: a study of 5 years’use. Stn. Bull. 511, For. Ser. 14. St. Paul, MN:University of Minnesota, Agricultural ExperimentStation. 27 p.

Roggenbuck, Joseph W.; Lucas, Robert C. 1987. Wil-derness use and user characteristics: a state-of-knowledge review. In: Lucas, Robert C., compiler.Proceedings-national wilderness research confer-ence: issues, state-of-knowledge, future directions;1985 July 23-26; Fort Collins, CO. Gen. Tech. Rep.

INT-220. Ogden, UT: U.S. Department of Agricul-ture, Forest Service, Intermountain ResearchStation: 204-245.

U.S. General Accounting Office [GAO]. 1989. Wilder-ness preservation: problems in some National For-ests should be addressed. GAO/RCED-89-202.Gaithersburg, MD: U.S. General AccountingOffice. 91 p.

Wallace, A; Romney, E. M.; Hunter, R. B. 1980. Thechallenge of a desert: revegetation of disturbeddesert lands. Great Basin Naturalist Memoirs.4: 2 16-225.

Willard, Beatrice E.; Marr: John W. 1971. Recoveryof alpine tundra under protection after damage byhuman activities in the Rocky Mountains ofColorado. Biological Conservation. 3: 181-190.

APPENDIX 1: FREQUENCY AND MEAN COVER OF SPECIES ON CAMPSITESAND CONTROL SITES IN THE EAGLE CAP WILDERNESS

Species

Frequency' Mean cover'Camps Controls Camps Controls

1979 1964 1990 1979 1984 1990 1979 1964 1990 1979 l984 1990Acer glabrumAchillea millefoliumAgrostis thurberianaAgrostis variabilisAllium validumAmelanchier alnifoliaAnaphalis margaritaceaAnemone oreganaAntennaria alpinaAntennaria lanataAntennaria microphyllaAquilegia flavescensArabis lyalliiArenaria aculeataArenaria macrophyllaArnica cordifoliaArnica mollisArnica parryiAster alpigenusAster conspicuusBromus vulgarisCalamagrostis canadensisCalamagrostis rubescensCalochortus eurycarpusCarex geyeriCarex luzulina

Carex micropteraCarex nigricansCarex rossiiCarex scopulorumCarex spectabilisCassiope mertensianaCastilleja chrysanthaCerastium arvenseChimaphila umbellataClaytonia lanceolataDanthonia intermediaDeschampsia cespitosaDisporum trachycarpumDodecatheon alpinumEpilobium alpinumEpilobium angustifoliumEpilobium sp.Erigeron peregrinusEriogonum flavum piperiEriogonum ovalifoliumFestuca occidentalisFestuca viridulaFragaria vescaGalium triflorumGaultheria humifusaGayophytum humileGentiana calycosa

Goodyera oblongifoliaHieracium albertinum

hieracium albiflorum

Hieracium gracile

0114000

79001012006010101142

1606310005001410902140021

1

1

14

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79001012005010102052

16

7

200

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3072

1706121013011111801172120

3

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1736250105211351

14111

101141

3

12

1

8 10

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1313

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173525010420

250

15111

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12

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12

14011121

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1627150105100420

16121

121140

5

14

0

11

0

.1

.1000

.71.0

00+0

.5+00

.30

.10

.20.2.5.4

30.7.70

2.6

.1000

.500

.2

.3+0

1.30

.l

.400

.5

.2

1.0

0

.1

+

+0

.1000

.5

.71.0

00+0

1.0.300

.40

.1

..20

.40

1.025.3

.60

3.4

.1000

.50

.1

.2

.1

.1

.70

.1

.1

.5+0

.9

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1.0

00

+

+

.1

.1000

.7

.81.2

00+0

6.31.1

00

.3

3.33.4

0

.30.9

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6.1.50.2.1

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.2

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.2

.3

.4

.21.6

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1.3

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.7

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.5

.50

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00

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4.547.6

1.13.83.6

.9

.40

.5

2.45.5

.5

.5

.2

.5

.22.22.0

.2

.52.4

.53.02.8

.5

.3

.5.3.5

.4

.3

.50

.51.0

.50.5

1.22.0

.5

.50

.51.04.01.2

01.4

.51.0

0.5.5.80

6.242.7

1.13.63.8

.6

.40

.5

3.83.0

00.l.40

2.1.5.2.5

3.5.5

3.03.0

0

.5

.5.a.5

.5

.3

.60

.1

.5

.5

.5

.5

2.3.5.50

.53.54.7

.8

.51.6

.82.5

00

1.0.50

3.537.0

1.33.53.1

.6

.40

.50

4.65.0

00

.2

.20

2.4.5.3.5

2.7.4

3.01.8

0

3.1

.5.70

.5(con.)

APPENDIX 1 (Con.)

Species

Frequency1 Meancover'Camps Controls Camps Controls

1979 1984 1990 1979 1984 1990 1979 1984 1990 1979 1984 1990Holodiscus discolor 0Hypericum anagalloides 0Hypericum formosum 0Juncus drummondii 2Juncus parryi 17Ledum glandulosum 1Lewisia pygmaea 3Ligusticum tenuifolium 5Linanthastrum nuttallii 0Lonicera utahensis 0Luzula hitchcockii 7L u z u l a p i p e r i 0Mitella pentandra 0Muhlenbergia filiformis 10Oryzopsis exigua 1Osmorhiza chilensis 0Pedicularis contorta 0Penstemon fruticosus 0Penstemon rydbergii 1Phleum alpinum 3Phyllodoce empetriformis 10Physocarpus malvaceus 0Poa gracillima 0Poa leibergii 0Poa sandbergiiPolemonium pulcherrimum 2Polygonurn phytolaccaefolium 0Potentilla diversifoliaPotentilla flabellifoliaPotentilla glandulosaPotentilla gracilis glabrataPyrola secundaRanunculus eschscholtziiRanunculus populagoRanunculus uncinatusRibes lacustreSagina saginoidesSenecio cymbalarioidesSenecio triangularisSibbaldia procumbensTaraxacum officinaleThalictrum occidentaleTrisetum spicatumTrisetum wolfiiTrifolium repensVaccinium caespitosumVaccinium membranaceumVaccinium scopariumVeratrum virideVeronica cusickiiVeronica serpyllifoliaVeronica wormskjoldiiViola aduncaViola orbiculataMoss

060010100110

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161

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11100023

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151912

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20011401

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141800

016

1152

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105111

-33

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.9

.2000

.l

.60000

.600

1.500+0

.l00++0

1.0

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.6

.9

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.7

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.2

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.2

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.400

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..3

.8

.5

.31.2

.1

.l0

00

+2.9

.33.11.5

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.71.2

.8

.5

.2

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.7

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.60000

.5

.50

1.800

.l00

.4

.l

.l0

.l2.0

.8

.8+0

.72.6

.6

.31.5

00

.10

.5

.5

.75.25.53.8

03.0

.5

.54.1

0.5.8.4

1.0.5.3

1.6.4

9.42.01.0

.5

.5

.81.11.07.3

.5

.54.0

.53.00

2.00

2.20

1.10

20.01.1

.50

3.81.0

20.01.03.1

00.7

2 . 0

..5

.5

.63.04.83.81.72.2

.51.55.1

.21.01.2

.5

.5

.5

.51.3

.48.75.0

.5

.5

2.7.8

1.04.9

.5

.53.0

.64.5

02.0

2.50

1.20

15.0.400

3.60

23.2.5

2.9.5..3

1.2.5

.50

.55.25.94.01.32.0

.5

.94.3

.2

.8

.8

.5

.41.0

.51.5

.310.63.5

.5

.5

.81.11.06.5

.5

.52.81.6

.50

2.0

.30

1.10

17.5.800

3.6.5

19.9.3

2.300

1.3

20 1.4 2.5 2.4 11.3 16.2 13.81Frequency is the number of sites, out of a maximum of 20, on which the species was found each year. Mean cover is the mean for all sites,

either campsite or control, on which the species was found at least once; it is not a mean for all 20 sites. A + indicates cover less than 0.05percent

36

APPENDIX 2: FREQUENCY AND MEAN COVER OF NONNATIVE SPECIES ONCAMPSITES IN THE BOB MARSHALL WILDERNESS

Frequency 1 Mean cover1

Species 1981 1990 1981 1990Agropyron repens 3 6 0.6 0.2Arabis glabra 2 1Capsella bursa-pastoris 9 3 .3 .2Chenopodium album 2 1 + +Dactylis glomerata 2 3 +Lychnis alba 2 0 .1 0Medicago lupulina 0 2 0Phleum pratense 8 8 .8 .7Plantago major 8 6 .2 .9Poa annua 2 5 .2Poa pratensis 20 21 7.4 12.1Polygonum aviculare 3 3 .8 .lRumex acetosella 1 3 .l .2Rumex crispus 3 2Taraxacum officinale 21 22 2.7 3.6Thlaspi arvense 4 5 .l .lTragopogon dubius 0 1 0 +Trifolium pratense. 3 1 + +

Trifolium repens 15 17 2.3 3.81Frequency is the number of campsites, out of a maximum of 29, on which the species was found

each year. Mean cover is the mean for all sites. A + indicates cover less than 0.05 percent.

APPENDIX 3: FREQUENCY AND MEAN COVER OF SPECIES ON CAMPSITEPERIMETERS AND CONTROL SITES IN GRAND CANYON NATIONAL PARK

Species

Frequency' Mean cover1

Camps Controls Camps Controls1994 1989 1984 1989 1984 1989 1984 1989

Acacia greggiiAcourtia wrightiiAgave utahensisAllionia incarnataAmelanchier utahensisAmsinckia intermediaAndrosace occidentalisAnemone tuberosaArabis perennansAristida arizonicaArtemisia arbusculaArtemisia ludovicianaAster spp.Astragalus newberryiAstragalus nuttallianusAstragalus spp.Atriplex canescensBaccharis salicifoliaBerberis fremontiiBernardia incanaBouteloua aristidoidesBouteloua curtipendulaBouteloua eriopodaBouteloua gracilisBromus rubensBromus tectoromCalochortus flexuosusCastilleja chromosaCastilleja linariaefoliaCeanothus greggiiCeanothus spp.Cercocarpus intricatusCercocarpus montanusCheilanthes parryiChrysothamnus nauseosusCirsium rothrockiiClaytonia perfoliataColeogyne ramosissimaCowania mexicanaCryptantha spp.Cymopterus purpurascensDelphinium parishiiDescurainia pinnataDichelostemma pulchellumDraba cuneifoliaDyssoides acerosaEchinocereus engelmanniiEchinocereus triglochidiatusElymus salinusEncelia frutescensEphedra nevadensisErigeron concinnusErigeron lobatusErigeron spp.

11 11 10 111 1 1 22 3 4 41 1 1 11 1 0 03 3 3 01 2 0 02 2 1 23 2 6 43 3 3 11 2 3 41 1 4 30 0 1 04 3 0 1

11 5 8 41 1 1 03 3 0 02 1 1 10 0 1 02 2 3 31 1 1 17 9 5 54 2 2 24 2 1 1

22 20 21 192 1 2 23 8 2 83 2 1 00 0 0 .01 1 0 00 0 0 21 1 0 00 0 1 11 1 0 02 2 5 31 0 0 03 1 2 16 6 7 65 5 3 36 6 4 31 2 3 30 0 1 0

10 4 6 22 4 3 37 3 5 01 0 1 02 5 2 20 0 2 30 0 1 0

25 21 20 20.3 2 2 0

1 0 1 00 1 1 0

38

17.01.41.0

.14.9

.1+.2+

.1

.3

.40

.1

.3

.32.4

.50

4.81.61.41.2

.923.9

.2++0

.60

.60

1.8

.213.03.0

.1+0

.1

.1

.1

.1

.100

1.38.4

.27.2

0

15.44.0

.8

.46.41.0

.1

.4+

.1

.4

.30

.l

.l

.32.0

.20

5.33.61.7

.4

.311.0

.1

.10

.60

.60

.21.5

0

12.12.9

.1+0

.8

.1+0

.100

1.48.9

+0+

26.4.1

1.83.0

0.40

.3

.3

.31.66.0

.50

.8

.50

1.5.5

4.615.0

2.14.5

.330.0

3.0.1.10000

3.00

1.70

1.213.3

.7

.2

.4

.5

.3

.4

.3

.5

.2

.3

.54.2

10.6.3

3.0.3

17.9.3

1.1.5000

.5

.2

.l1.11.6

0.l.200

1.50

4.63.01.49.6

.818.13.0

.3000

.50

3.00

.30

.511.1

.6

.2

.40

.5

.400

.2

.50

2.28.7

000

(con.)

APPENDIX 3 (Con.)

Species

Frequency MeancoverCamps Controls Camps Controls

1984 1989 1984 1989 1984 1989 1984 1989Eriogonum inflatumEriogonum spp.Erioneuron pilosomErioneuron pulchellumErodium cicutariumFallugia paradoxaFendlera rupicolaFraxinus anomalaGalium aparineGalium stellatumGilia flavocinctaGiossopetalon nevadenseGutierrezia sarothraeHaplopappus acradeniusHaplopappus spinulosusHilaria jamesiiHordeum leporinumHymenoxys acaulisJuniperus osteospermaLepidium lasiocarpumLepidium montanumLeucelene ericoidesLupinus brevicaulisLycium andersoniiMammillaria tetrancistraMentzelia pumilaMirabilis multifloraMuhlenbergia porteriOenothera hookeriOpuntia basilarisOpuntia chloroticaOpuntia erinaceaOpuntia phaeacanthaOryzopsis hymenoidesParietaria hesperaPenstemon eatoniiPectocarya recurvataPhacelia cryptanthaPhacelia glechomaefoliaPinus edulisPfagiothrys arizonicusPlantago purshiiPoa bigeloviiPoa fendlerianaPorophyllum gracilePtelea trifoliataQuercus undulataRhus trilobataSenecio multilobatusSitanion hystrixSphaeralcea parvifolia

Sphaeralces parvifoliaSporobolus cryptandrusStipa aridaStipa comata

1 2 0 01 1 0 00 1 0 05 2 4 0

14 11 7 63 3 3 30 0 1 10 0 1 12 3 1 01 1 0 05 0 3 07 7 6 7

21 20 19 174 4 3 32 2 0 03 0 2 04 3 2 21 1 1 15 5 6 5

11 6 9 52 0 1 11 2 4 21 1 1 12 3 1 10 0 0 21 0 0 00 3 0 13 2 3 20 1 0 01 1 2 00 1 0 05 4 2 21 1 1 11 1 0 05 2 4 20 0 1 11 0 0 03 0 3 02 0 2 01 3 3 32 0 0 0

13 6 13 110 4 4 0

8 6 8 12 2 1 11 1 1 11 1 1 14 4 2 11 2 2 15 2 5 3

15 13 14 131 2 1 27 5 9 78 9 8 71 1 2 2

.2

.30.l.3

9.700.5.l.5

4.42.8

14.4.4.l

6.8.1

12.8.3

.3

.20+0

.60.l0.7.l.8.60.l

1.7.l

2.3

.6

.2

.41.7

23.25.62.9

+.1

.5

.81.1

.5

.3

.4+

.38.5

00

.6

.60

3.92.1

11.9.90

6.4

16.3.30.l

.500

2.2.8.l.1.l.4.l

2.2.l0000

2.80+

.31.0

14.17.24.7

++

000.3.3

11.33.03.0

.l0

.88.35.7

17.00

1.2.2.5

10.6.3.3

1.8.5.8000

1.8.0

1.80

3.00

1.2.50

1.3.3

4.60.8

1.01.01.5

15.0.5

2.6.5.3

.4 .8

.l .21.3 .91.8 1.7

5 6.0

0000.2

11.33.03.0

000

8.33.1

17.000

1.2.5

10.1.2.3.6.5.8.50

.2

.2000.2.50

.2

.5000

4.60+0.l.3

15.01.52.5

.32

.6

.3

.51.2

.3(con.)

APPENDIX 3 (Con.)

Frequency Mean coverCamps Controls Camps Controls

Species 1984 1989 1984 1989 1984 1989 1984 1989Stipa speciosa 2 2 0 0 .1 .1 0 0Stipa sp. 0 1 0 0 0 .7 0 0Streptanthus cordatus 1 4 0 0 + + 0 0Swertia albomarginata 0 0 1 0 0 0 .5 0Thamnosa montana 1 1 3 2 .3 .2 1.6 .3Thelypodiopsis linearifolia 1 0 1 0 + 0 .5 0Thysanocarpus Iaciniatus 3 2 2 2 + + .3 .3Tragopogon dubius 2 0 0 0 +

.50 0 0

Vulpia octoflora 11 2 8 0 .1 .8 0Yucca angustissima 1 1 2 1 .2 .7 1.8 .3Yucca baccata 3 4 6 6 1.6 1.9 1.8 1.8Moss 18 8 15 5 6.8 3.7 10.0 4.4

1Frequency is the number of sites, out of a maximum of 22, on which the species was found each year. Mean cover is the mean for all sites,either campsites or control, on which the species was found at least once; it is not a mean for all 22 sites. A + indicates cover less than 0.05percent.

Cole, David N.; Hall, Troy E. 1992. Trends in campsite condition: Eagle Cap Wilderness,Bob Marshall Wilderness, and Grand Canyon National Park. Res. Pap. INT-453. Ogden,UT: U.S. Department of Agriculture, Forest Service, lntermountain Research Station. 40 p.

The overall trend in condition on established campsites was one of slight deterioration,with the most deterioration occurring in campsite area, mineral soil exposure, and treedamage. Impacts to ground cover vegetation were relatively stable. Differences in amountof impact between high-use and low-use sites generally increased over time.

KEYWORDS: ecological impact, campsites, wilderness, backcountry, trends

United States Department Trends in Campsite Condition...

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