literature review for the vermont trail collaborative - university of
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Literature Review for the Vermont Trail Collaborative:
Summary of Findings and Annotated Bibliography
Edited and Organized by:
William Valliere, University of Vermont
Compiled by the Vermont Trail Collaborative Science Panel:
Doug Blodgett, Vermont Fish and Wildlife Department
Lisa Chase, University of Vermont
Don Dickson, Sierra Club
Jim Harding, Green Mountain College
Rees Harris, CCC of VT
Rob Hoelscher, US Forest Service
Anthony Iarrapino, Conservation Law Foundation
Robert Manning, University of Vermont
Mollie Matteson, Center for Biological Diversity
Peter Pettengill, University of Vermont
William Valliere, University of Vermont
Bryant Watson, Vermont Association of Snow Travelers
For more information, contact:
Lisa Chase
University of Vermont Extension
11 University Way #4
Brattleboro, Vermont 05301
(802) 257-7967
www.uvm.edu/tourismresearch/trails
July 13, 2011
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Contents
Executive Summary ........................................................................................................................ 3 Key Findings ............................................................................................................................... 3 Research Needs (not in order of priority) ................................................................................... 4 Recreation Conflict ..................................................................................................................... 5
User-Caused Noise in Recreation Settings ................................................................................. 5 Hiking ......................................................................................................................................... 5 Non-Motorized Winter Trail Use................................................................................................ 6 Mountain Bike Use ..................................................................................................................... 6
Snowmobile Use ......................................................................................................................... 6 Off-Highway Vehicle (OHV) Use .............................................................................................. 7
Horseback Riding and Pack Stock Use ....................................................................................... 8 Annotated Bibliography .................................................................................................................. 9
Recreation Conflict ..................................................................................................................... 9 User-Caused Noise in Recreational Settings ............................................................................ 12 Hiking ....................................................................................................................................... 14
Non-Motorized Winter Trail Use.............................................................................................. 16 Mountain Bike Use ................................................................................................................... 18
Snowmobile Use ....................................................................................................................... 23 Off-Highway Vehicle (OHV) Use ............................................................................................ 31 Horseback Riding and Pack Stock Use ..................................................................................... 39
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Executive Summary
The Science Panel Work Group of the Vermont Trail Collaborative compiled this document to
address the need for a review of current research related to trails and recreation on the Green
Mountain National Forest and other areas of Vermont. A wide variety of environmental and
social impacts from forest-based recreation are documented in the literature, including those
related to soil erosion and trail degradation; vegetation; water and air quality; noise; wildlife and
fish; and social conflicts among different types of recreation user groups. Key findings from the
literature review are summarized below, following by annotated bibliographies. Citations were
gathered through a literature review of published research reports and peer-reviewed scholarly
writing, and from a review of internet sources. Research contained in this document spans a wide
variety of types of research including studies reported in peer-reviewed journals as well as
literature published without peer-review, through organizations and agencies.
This document is a compilation of studies submitted by members of the Science Panel, the
Vermont Trail Collaborative, and students from the Green Mountain College working under the
supervision of Professor Jim Harding. Studies submitted were reviewed and organized by Bill
Valliere, Research Specialist for the Park Studies Lab and Vermont Tourism Data Center at the
University of Vermont. Many individuals with a variety of opinions and points of view
contributed to this document, which is not meant to be interpreted as an expression of consensus.
Rather, this document is a compilation of summary statements about scientific studies that are
factual and accurately represent the research published.
For links to selected studies listed below, visit www.uvm.edu/tourismresearch/science
For more information on the Vermont Trail Collaborative, visit
www.uvm.edu/tourismresearch/trails
Key Findings
Social and ecological impacts result from outdoor recreation. The degree of these
impacts varies across different types of recreation and setting.
Ecological and social impacts of recreation can be mitigated by trail design and
management, zoning and education of users.
Recreation conflict is perceived to be increasing, due partially to new
technologies, activities and equipment.
User-caused noise in recreation settings negatively affects wildlife and the visitor
experience at times. The physical and social aspects of visitor-caused noise are
difficult to generalize from place to place, due to differences in geography and
desired recreational experiences.
A great deal of recreation research has focused on hiking and its impacts on
resources and the visitor experience. Less is known about the effects of hiking on
wildlife.
Research on ecological impacts of mountain biking has mixed results. Some
studies report impact from mountain bikes similar to impacts from hiking activity
while others report greater ecological impact. Ecological impact is greatly
affected by trail slope and construction, location, and intensity of use.
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A number of studies have been conducted in regards to impacts of motorized
recreation. These include impacts to air and water quality, vegetation, soil, and
wildlife. Findings suggest impacts are specific to the context of study. Motorized
forms of recreation typically have greater impacts on trails than non-motorized
recreation.
Sixteen of the twenty-five studies referenced below were either conducted in
ecological or geographical zones not common to Vermont, or were conducted on trail
systems not specifically managed for OHV use. OHV use was allowed on all trail
systems studied. These studies indicate negative environmental impacts of OHVs
and concerns about user conflicts, and user-caused noise. OHV use can also have
negative effects on wildlife, although some mammals (deer and big horn sheep,
for example) may become habituated to these vehicles. The remaining publications
were reviews of the literature, or statements about land management agency policies.
While OHVs offer access to resource areas that are typically more remote,
allowing access to these areas by individuals that may not otherwise have the
ability to enjoy the outdoors, most studies do not support their use, especially in
sensitive areas, not specifically designed and managed for such use.
Most research on horseback riding and pack stock use has been conducted in the
western United States. Studies on the ecological effects of stock use on trails
generally conclude that stock use can have detrimental effects on trails and be a
vector to spread invasive species.
Research Needs (not in order of priority)
More research on recreation conflict and displacement is needed regarding
specific recreation uses, especially activities growing rapidly in popularity in
Vermont such as mountain biking and OHV use.
Research about user-caused noise in recreation settings is limited in scope. More
research is needed in recreational settings of special interest in Vermont.
The effects of recreation on soil and vegetation are greatly localized, making
generalization difficult. There is a need to do this type of research in specific
areas of interest in Vermont.
More study of non-motorized winter activities is needed, particularly the effects
of increasing use and the potential for conflict with other types of users.
A recent study on the effects of snowmobiles on water quality has contributed
much needed data. Additional study on the effects of snowmobiles on air and
water quality is needed in Vermont to determine the localized effects from
snowmobiles.
More studies of the impacts of motorized recreation are needed in Vermont since
most available studies have been conducted in different geographical zones.
These studies should include impacts to air and water quality, vegetation, soil, and
wildlife. Additionally, studies to determine the percentage of 2-stroke versus
cleaner 4-stroke engines currently in use in Vermont should be conducted for both
OHVs and snowmobiles. Finally, the number of users of OHVs and snowmobiles
who would otherwise not be able to enjoy the outdoors should be determined.
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More study of trail riding and pack stock effects on wildlife, trail erosion and
spread of invasive species may be warranted in Vermont, as this activity increases
in popularity.
Recreation Conflict
Conflict is often referred to as ‘goal interference’ in the context of recreation, i.e., when one
individual’s or group’s recreational activities prevent the attainment of another individual’s or
group’s recreational goals. Substantial recreation conflict between groups and activities has been
found in outdoor recreation, and has been the subject of much research throughout the U.S.
Recreation conflict may be increasing, in part, because of new technologies, activities and
equipment. Studies have found that recreation conflict is related to many variables which include
specific motivations for recreation, perceived similarity of groups or activities, level of
experience, tolerance for sharing a resource and safety concerns. Zoning or separating recreation
groups or activities can be effective in managing recreation conflict. The asymmetric or one-way
nature of much recreation conflict suggests that management is needed to maintain a high quality
experience for individuals who are sensitive to conflict. More research is needed regarding
specific recreation uses, especially activities growing rapidly in popularity such as mountain
biking and OHV use.
User-Caused Noise in Recreation Settings
The issue of visitor-caused noise in outdoor recreational settings is a relatively new area of study.
Research that is available looks at the effects of visitors-caused noise on wildlife and the
experience of other visitors. Since this is a relatively new area of research, generalizations are
difficult to make, and more research is needed in diverse recreational settings. The physical and
social aspects of noise vary dramatically from place to place. Therefore, more research is
necessary, particularly in areas of special interest, to determine how visitor-caused sound travels
through the areas, and how that sound affects various types of users and wildlife in those areas.
Hiking
A great deal of research has been done on the ecological effects hiking has on trails. This
research generally takes the form of trampling studies in various types of soils and vegetation to
determine how resistant and resilient different recreational areas are. Since soil and vegetation is
greatly localized, generalization can be difficult. Therefore, there is a need to do this type of
research in specific areas of interest.
Studies on the effects of hiking on wildlife are not as prevalent. The few studies that have been
done show that some ungulates show a greater reaction (surprise) from this type of recreation
than to some forms of motorized recreation, and they do not habituate to it.
A great deal of research has been done on the effects of increasing use of trails by hikers, and
comprises an area of study called social carrying capacity. Frameworks for this research have
been developed and are widely applied, primarily in summer conditions. Less is known about
other times of year and other uses (i.e., snowshoeing and cross country skiing).
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Non-Motorized Winter Trail Use
There are few studies on the effects of non-motorized winter trail use on wildlife. The studies
that have been done show that, like hiking, some ungulates show a greater reaction (surprise)
from this type of recreation than to some forms of motorized recreation, and they do not
habituate to it.
As mentioned above, a great deal of research has been done on the effects of increasing use of
trails by hikers. Less is known about other times of year and other uses (i.e., snowshoeing and
cross country skiing). Studies of both the ecological and social effects of these activities can be
conducted using similar methods as studies about hiking. Carrying capacity frameworks can
easily be adapted and applied to these forms of recreation, while new methods for winter ecology
may need to be developed.
Mountain Bike Use
Since mountain biking is a relatively new form of outdoor recreation, it has not been as well
studied as hiking. However, there is a growing body of literature about this activity. Research
on the ecological effects of mountain biking have often been comparative studies, comparing the
effects of mountain bikes to the effects of hiking. This research seems to be inconclusive. Some
studies report that mountain bikes cause greater trail erosion potential than hiking, while other
studies indicate that the effects are similar. Two variables that seem to mitigate these effects are
steepness of the trail studied and how the trail is constructed.
There are fewer studies of the social effects of mountain biking on other uses. Some reports of
recreational conflict have been documented, both unidirectional and bidirectional. Studies report
that zoning or user education can mitigate recreational conflict.
Snowmobile Use
Several studies have been conducted, including a recent study in Vermont, to look at the effects
of snowmobiling on snow pack runoff water quality. While a study in Yellowstone National Park
showed concentrations of ammonium, nitrate, sulfate, benzene, and toluene in snow were
positively correlated with snowmobile use, the recent Vermont study suggests that snowmobile
use does not have significant impacts on the surface water quality in the vicinity of heavily used
snowmobile trails. This apparent divergence of results may be due to the intensity of use in the
Yellowstone region as compared to use in Vermont.
Studies of air quality often focus on the emission effects of snowmobile operation. Many of these
studies have focused on the region in and around Yellowstone National Park. Findings from
some studies suggest that emissions may exceed human health standards in some areas. More
study is needed in the east to determine what the localized effects from snowmobiles might be.
Further research is needed about the effects of snowmobile emissions on air quality. Recent
studies on air quality examine the differences between older (2 stroke) engines versus newer (4
stroke) engines. Research of this type generally finds newer engines to produce fewer emissions
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than older engines. Research in Vermont should focus on the percentage of older (2 stroke)
versus the newer (4 stroke) engines in use.
Most studies of the effects of motorized recreation on wildlife have taken place in Western
habitats and have often focused on snowmobile use. Studies show that some wildlife species are
negatively impacted by the presence of motorized recreation, although some mammals (deer, for
example) may become habituated to these vehicles. Snow compaction from snowmobiles may
also affect the survival and activities of small mammals. Studies of snowmobile impacts on
wildlife in eastern settings are limited.
Snowmobile use can conflict with non-motorized uses, such as snowshoeing and cross-country
skiing. Additionally, noise and intrusion of the modern world into nature may compromise the
enjoyment of some user groups. The numbers of snowmobilers, and their intensity of use, can
reduce the positive experiences of other visitors, potentially resulting in displacement of the
other users. It is unclear whether conflict between snowmobiles and other recreationists is
unidirectional or bidirectional, and more research is needed.
Off-Highway Vehicle (OHV) Use
The vast majority of studies indicate negative environmental impacts of OHVs and concerns
about user conflicts, and user-caused noise. Sixteen of the twenty-five studies referenced below
were either conducted in ecological or geographical zones not common to Vermont, or were
conducted on trail systems not specifically managed for OHV use. More studies of the impacts of
motorized recreation are needed in Vermont since most available studies have been conducted in
different geographical zones. OHV use was allowed on all trail systems studied. In general,
motorized forms of recreation have greater impacts on trails than non-motorized recreation.
Research generally shows similar impacts across different types of motorized recreation.
Differences in impacts across types of motorized recreation are often due to intensity of use.
Further research is needed about the effects of OHV emissions on air quality. More recent
studies on air quality examine the differences between older (2 stroke) engines versus newer (4
stroke) engines. Research of this type generally finds newer engines to produce fewer emissions
than older engines. Research in Vermont should focus on the percentage of older (2 stroke)
versus the newer (4 stroke) engines in use.
Soil and vegetation studies are numerous in the literature. Soil compaction and the shear forces
of motorized vehicles can alter hydrologic patterns and intensify erosion on trails where they are
used. Many studies of this type have been done in the arid southwestern United States and in the
west. More studies are needed to quantify the amount and extent of soil loss attributable to
motorized recreation use in the Northeast.
OHV use has negative effects on wildlife. Most studies of the effects of motorized recreation on
wildlife have taken place in Western habitats and, as mentioned above, have often focused on
snowmobile use. Studies show that some wildlife species are negatively impacted by the
presence of motorized recreation, although some mammals (deer and big horn sheep, for
example) may become habituated to these vehicles. Studies of impacts from motorized recreation
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on wildlife in eastern settings are limited. These types of studies should be conducted in
Vermont.
While OHVs offer access to resource areas that are typically less accessible and more remote,
allowing access to these areas by individuals that may not otherwise have the ability to enjoy the
outdoors, this type of use can conflict with non-motorized uses, such as hiking, wildlife
photographers, birdwatchers, etc. While there are national standards for OHV’s that have been
accepted by the US Forest Service, Bureau of Land Management, and by state and local land
managers across the country, noise and intrusion of the modern world into nature may
compromise the enjoyment of some user groups. More research is needed in this area. The
numbers of motorized recreationists, and their intensity of use, can reduce the positive
experiences of non-motorized visitors, potentially resulting in displacement of the non-motorized
users. It is unclear whether conflict between motorized and non-motorized recreationists is
unidirectional or bidirectional, and more research is needed. Research is also needed to estimate
the prevalence of OHV users who are otherwise unable to enjoy the outdoors.
Horseback Riding and Pack Stock Use
Most research on trail riding and pack stock use has been conducted in the western United States
where stock use is more prevalent. Studies on the ecological effects of stock use on trails include
effects on wildlife, trail erosion potential, and spread of invasive plant species. Studies generally
conclude that stock use can have detrimental effects on trails and be a vector to spread invasive
species. More study of trail riding and pack stock effects on wildlife, trail erosion and spread of
invasive species may be warranted in Vermont, as this activity increases in popularity.
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Annotated Bibliography
Recreation Conflict
Chavez, D., Winter, P., and Baas, J. 1993. Recreational mountain biking: A management
perspective. Journal of Park and Recreation Administration 11(1): 29-36. Retrieved on
September 7, 2010 from: https://www.sagamorepub.com/ebooks/User/jpra1-
18/JPRA11.3543/1993_11_3_29-36.pdf>
This article discusses the results of a telephone survey that was given to 40 recreational
managers from the USDA Forest Service and the USDI Bureau of Land Management. Its
purpose was to determine the potential issues associated with mountain bike management. In
their findings it was found that one-third of the managers reported resource degradation due to
mountain biking, and over half reported conflict with other recreational user groups.
Hendircks, W., Ramthun, R., and Chavez, D. 2001. The effects of persuasive message source
and content on mountain bicyclists' adherence to trail etiquette guidelines. Journal of Park &
Recreation Administration. 19(3): 36-61.
Land managers have adopted a number of traditional and contemporary direct and indirect
management strategies to deal with this relatively new recreational phenomenon. Among the
educational approaches that have been employed are trail etiquette guidelines designed to reduce
social and environmental impacts on multiple-use trails. This study examined the effects of three
sources of messages and two appeal types on mountain bicyclists’ compliance with trail etiquette
on Mt. Tamalpais in Marin County, California. The three message sources were a volunteer
biker, a volunteer hiker, or a uniformed volunteer who was hiking. The results of the study
provide support for the use of volunteers to assist in communicating appropriate trail etiquette
protocol and suggest that having volunteers in uniform may not be the most effective means of
educating mountain bicyclists. Volunteer patrols are a potentially successful approach to
encourage appropriate behavior on multiple-use trails, and in-group volunteers such as mountain
bikers who contact other bicyclists should be considered by land management agencies.
Jacobi, C. and R. Manning. 1999. Crowding and Conflict on the Carriage Roads of Acadia
National Park: An Application of the Visitor Experience and Resource Protection Framework.
Park Science. 19(2): 22-26.
http://www.uvm.edu/tourismresearch/trails/Crowding_and_Conflict.PDF
This study focused on crowding and recreational conflict on the Carriage Roads of Acadia
National Park. The carriage roads offer multiple recreational uses that include pedestrian,
cyclist, and equestrian use. Due to increased number of complaints regarding ‘crowding’ and
‘conflict’ this study was conducted in coordination with Acadia National Park. While equestrian
use is permitted on the trail system, its impacts were not considered for this study. The three
most important problem behaviors for users were bicycles passing from behind without warning,
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excessive bicycle speed, and users obstructing the road. Findings also showed that local
residents, who use the roads primarily for hiking, are being displaced by increasing numbers of
cyclists, who tend to be visitors to the area. As a coping mechanism, residents have tended to
use the carriage roads less often and have shifted their use to less frequently used times and
places.
Manning, R. 1999. Recreation conflict. Studies in Outdoor Recreation. Book chapter: 194-
206.
This book chapter encompasses a number of empirical studies related to conflict, discusses
theoretical models of recreational conflict, and offers management options to resolve conflict as
well. A list of conflicting uses is provided that includes a myriad of uses including motorized
and non-motorized. Conflict is often referred to as ‘goal interference’ in the context of
recreation and can be related to a number of variables including motivations, level of experience,
social values, expectations for encountering other types of use, and tolerance for sharing
recreational resources. The two managerial options related to recreational conflict that are
discussed are zoning and education.
Norling, J. C. 2010. Kingdom Trails Study Fall 2009 Results. Unpublished report. Lyndon State
College.
This study, funded by the Kingdom Trails Association (KTA), primarily sought to understand
KTA user demographics, use patterns, perceived conflict and attitudes associated with selected
behaviors. Most of the respondents were cross-country mountain bikers (79%). In general, few
conflicts were reported. Most conflicts that were reported were in response to other users
blocking the trail when resting. Some crowding was also reported at trailhead parking lots.
Stowkowski, P.A. & LaPointe, C.B. 2000. Environmental and Social Effects of ATV's and
ORV's: An Annotated Bibliography and Research Assessment.
http://www.uvm.edu/tourismresearch/trails/ohvbibliogVT00.pdf
This annotated bibliography discusses the environmental and social effects of ATV’s and
ORV’s. It encompasses and describes a number of articles that are relevant to recreational
conflict in public land settings.
Watson, A., Williams, D., & Daigle, J. 1991. Sources of conflict between hikers and mountain
bike riders in the Rattlesnake NRA. Journal of Park and Recreation Administration, 9(3): 58-
71. Retreived on September 7, 2010 from: https://www.sagamorepub.com/ebooks/User/jpra1-
18/JPRA9.3765/1991_9_3_59-72.pdf
Mountain bike riders and hikers in the Rattlesnake National Recreation Area were studied to
assess the extent of conflict between the two groups and to search for underlying reasons. The
article concludes that educating mountain bike riders about behaviors that others consider
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unacceptable and educating hikers about the similarities between hikers and mountain bike riders
may reduce feelings of conflict. More direct management approaches must also be considered.
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User-Caused Noise in Recreational Settings
Newman, P. Manning, R. Trevino, K. 2010. From landscapes to soundscapes: Introduction to
the special issue. Park Science. 26(3): 2-5.
This introduction to a special issue of Park Science considers the acoustic environment of
national parks and focuses on the aural impacts of human-caused noise. It not only introduces
management policies of the National Park Service related to noise, but also provides a useful
conceptual framework for understanding ‘soundscapes.’ The model stems from other
frameworks that guide management in national parks and other protected areas. It incorporates
components of anthropogenic sound, audibility, annoyance, and dissatisfaction to provide a
means of organizing and integrating emerging themes from current soundscape research.
Kariel, H.G. 1990. Factors affecting responses to noise in outdoor recreational environments.
The Canadian Geographer. 34(2): 142-149.
This study sought to find a relationship between relative loudness of sounds on an annoyance-
pleasantness scale. No relationship was found. However, a list of most common annoying
sounds was produced. The top three annoying sounds from this list included rowdy people,
music, and motorcycles.
Graham, O.J. 1999. Measuring the effects of commercial jet boats on the Dart River on the
experiences of recreationists in natural settings. Noise Control Engineering Journal. 47(3):
104.
This study reported on the impact of commercial jet boats on the Dart River. Findings stated that
22% of visitors were annoyed by the noise of jet boats. At the same time, they noticed seeing an
average of between 4 and 7 boats. Doubling this number of jet boats suggests a level of impact
that could ruin visitors experience.
Vitterso, J., Chipeniuk, M. Skar, and Vistad, O. Recreational conflict is affective: The case of
cross-country skiers and snowmobiles. Leisure Sciences. 26(3): 227-243.
Skiers contacted in this study reported being negatively impacted by snowmobile encounters.
Skiers were asked to rate the impact of noise from snowmobiles in this study. Those who did
encounter snowmobiles were more sensitive to noise than those who did not.
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Barber, J. Turina, F. Fristrup, K. 2010. Tolerating noise and the ecological costs of
‘habituation’. Park Science. 26(3): 24-25.
This article discusses the patterns of wildlife and their ability to adapt to their surroundings.
Theory and observations however refute this case in terms of noise. For instance, declining
dolphin populations inside tourist areas have been attributed to increased boat use and their
associated noise. Other examples illustrate the articles point that wildlife may become tolerant to
noise, but not habituate. This could carry ecological costs.
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Hiking
Bryan , Rorke B. 1977. The Influence of Soil Properties on Degradation of Mountain Hiking
Trails at Grovelsjon. Geografiska Annaler. Series A, Physical Geography. 59(1/2) pp.49-65.
Due to the rapid increase in recreational use above tree line in Swedish mountains, hiking has led
to trail erosion and degradation. Soil is impacted most during periods of high use and is
dependent upon soil type. Soils with high moisture content are especially vulnerable to impacts
of hiking.
Cole D. 1987. Effects of three seasons of experimental trampling on five montane forest
communities and grassland in Western Montana, USA. Systems for Environmental Management,
Missoula, Montana.
This is a report on the outcomes from experimental trampling in Western Montana. Sampling
sites incorporated six vegetation types including five forest areas and one grassland.
Comparisons were made between the amount of trampling and the loss of vegetative cover. The
amount of each species lost was measured in order to see how different plants varied in
resistance and resilience. Findings suggest the relationship between degree of trampling and
increase in soil exposure is linear, and that the level of impact may take years to level off.
. Dale, D., and T. Weaver. 1974. Trampling Effects of Impacts on Trail Cooridors of North Rocky
Mountain Forests. Journal of Applied Ecology. 11(2).
This study focused on trail impacts within Montana and Wyoming. Findings suggest that hiking
trail widths increase with increased use. However, horse use on the trail only made the trail
deeper and not wider. Results also suggest that similar impacts on vegetation may be found at
campsite areas.
Fairbanks, W.S. and R. Tullous. 2002. Distribution of pronghorn (Antilocapra Americana Ord)
on Antelope Island State Park, Utah, USA, before and after establishment of recreational trails.
Natural Areas Journal. 22. pp. 277-282.
This study was located on Antelope Island in Great Salt Lake and recorded the presence of
antelope the year before trails were opened and for three years after opening. Findings suggest
that antelope groups stay further away from trails and do not become habituated to trail users
over time.
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Leung, Y. and Marion, J. 2000. “Recreation impacts and management in wilderness: a state of
knowledge review”. USDA Forest Service Proceedings. Vol. 5.
This article summarizes recreation impact management studies from the last 15 years in the U.S.
It provides an overview of general trail impact research and a number of sources for more
information. The major findings from the most recent studies are summarized in the conclusion.
Marion, J.L. & Leung, Y. 2001. Trail resource impacts and an examination of assessment
techniques. Journal of Park & Recreation Administration. 19 (3) 17-37.
This article discusses different types of trail impacts and various ways of assessing them, such as
inventory, maintenance, and condition. It compares two methods of assessing impact and
suggests that quantitative results vary by methodology used.
Studler, Susan. 1980. Trampling Effects on Bryophytes: Trail Surveys and Experiments. The
Bryologist. 83(3) pp. 301-313.
Findings of this study suggest that the effects of trampling vary for different types of bryophytes.
The experimental study focused on the impacts of hiking on vegetation in Mountain Lake,
Virginia. Thirty-five species were studied and all showed negative effects caused by hiking
within the area.
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Non-Motorized Winter Trail Use
Cassirer, E.F., Freddy, D.J. and Ables, E.D. 1992. Elk responses to disturbance by cross-country
skiers in Yellowstone National Park. Wildlife Society Bulletin 20:375-381.
This study found that restricting skiers to areas greater than 650 meters away from elk winter
range would minimize disturbance of most non-habituated elk. Skiers would have to remain at
distances of more than 1,700 meters to completely avoid disturbing elk. The study concluded that
skier use on elk winter range should be concentrated in the smallest possible are.
Freuler, Benjamin, Marcel Hunziker, and Heinz Gutscher. 2006. Snowshoeing in Protected
Areas: Bridging the Gap between Attitude and Behaviour. Exploring the Nature of
Management. pp. 294-95.
This article focuses on snowshoeing in protected areas. Findings suggest that visitors prefer to
snowshoe on land that is also prime habitat for rare species. One way to reduce this conflict is
through limiting use. Influencing human behavior through psychological frameworks was also
suggested.
Morrison, J.R. 1995. Effects of Ski Area Expansion on Elk. Wildlife Society Bulletin, 23(3).
This study considered two different populations of elk to the expansion of ski resorts. At Vail,
disturbances were mainly ground disturbances, while at Beaver Creek there was an increase in
human activity. At both sites the elk reacted poorly to the disturbances. At Vail, elk use
decreased by thirty percent in the newly developed ski bowl. At Beaver Creek elk levels dropped
when human activity was highest. There was some recovery, and some elk did begin to use the
areas again in the years after the disturbance, however there does not look like there will be a full
recovery.
Ries, J.B. 1996. Landscape Damage by Skiing at the Schauinsland in the Black Forest, Germany.
Mountain Research and Development, 16(1).
The development of ski runs in the Black Forest has not been beneficial to the environment.
There have been a large number of unfavorable impacts, such as vegetation and topsoil loss,
resulting in soil erosion and frozen water impacts. There have been studies that have dealt with
these impacts in alpine areas, but not many in the lower reaches. There is a great variability in
snow depth and cover in these areas. The study indicates graded areas are more susceptible to
trail impacts. The areas that are narrow and force skiers to turn are prone to more vegetative
impacts from ski edges. Ski run maintenance also damages the ski run as well and digs up soil
and kills vegetation. Snow levels have also been low in the 18 years preceding this study, which
did not help lessen the impacts.
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Thiel, Dominik, et al. 2008. Ski tourism affects habitat use and evokes a physiological stress
response in capercaillie Tetrao urogallus: a new methodological approach. Journal of Applied
Ecology 45(3) pp. 845-853.
This article focuses on the study of ski tourism affecting the European Wood Grouse. The study
concluded that the wood grouse’s habitat was mainly in ski tourism areas. It also found that the
wood grouse avoided high ski areas. In conclusion the wood grouse is negatively affected by ski
tourism, which displaces them from their habitat and also messes with their endocrine system.
Illich, I.P. 1994. Responses of Assemblages of Orthoptera to Management and Use of Ski Slopes
on Upper Sub-alpine Meadows in the Austrian Alps. Oecologia, 97(4).
In this article researchers studied how many grasshoppers they encountered along transects in
meadows where skiing is permitted and not permitted. They found that they there was more
species diversity in both grasshoppers and flora in unused meadows than used meadows. The
study indicates that there is lower diversity, lower population size and quicker development in
grasshoppers in used meadows than unused meadows. Grasshoppers that prefer tall grasses do
not live in used alpine meadows since there is not as much vertical structure due to compaction
from skiing.
18
Mountain Bike Use
Taylor, A., and Knight, R. 2003. Wildlife Responses to Recreation and Associated Visitor
Perceptions. Ecological Society of America 13: 951-963.
This study is an overview of the different types of recreational impacts that effects several
species of wildlife. The researchers examined the responses of bison, mule deer, and pronghorn
antelope to hikers and mountain bikers at Antelope Island State Park, Utah, by comparing alert
distance, flight distance, and distance moved. Within a species, wildlife did not respond
differently to mountain biking vs. hiking, but there was a negative relationship between wildlife
body size and response.
Cessford, Gordon R. (1995). Off-Road Impacts of Mountain Bikes. Science and Research Series,
No. 92. Dept. of Conservation. Wellington, NZ. Retrieved on September 7, 2010 from:
http://www.mountainbike.co.nz/politics/doc/impacts/index.htm.
This article discusses many different aspects of mountain biking including the impacts that it has
on trails and natural resources, and the unique impact potential from wheels. It compares the
impacts that mountain biking has on trails to the impacts that other trail users have such as
walkers, horses, and motorbikes, and discusses the recreational conflict that sometimes happens
between different types of recreational users. It also discusses the setting and recreation
experience preferences of mountain bike riders.
Chavez, D., Winter, P., and Baas, J. 1993. Recreational mountain biking: A management
perspective. Journal of Park and Recreation Administration 11(1): 29-36. Retrieved on
September 7, 2010 from: https://www.sagamorepub.com/ebooks/User/jpra1-
18/JPRA11.3543/1993_11_3_29-36.pdf>
This article discusses the results of a telephone survey that was given to 40 recreational
managers from the USDA Forest Service and the USDI Bureau of Land Management. Its
purpose was to determine the potential issues associated with mountain bike management. In
their findings it was found that one-third of the managers reported resource degradation due to
mountain biking, and over half reported conflict with other recreational user groups.
19
Chavez, D.J. 1996. Mountain Biking: Issues and actions for USDA Forest Service managers. RP-
PSW-226. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest
Research Station. Retrieved on September 7, 2010 from:
http://www.treesearch.fs.fed.us/pubs/28586.
Managers of National Forests are faced with many challenges related to the growing use
of mountain bikes. To determine the issues and management actions associated with this
growth, USDA Forest Service managers from across the United States were surveyed.
Managers from at least two National Forests from every Region (except Alaska) reported
annual use of trails by 10,000 or more mountain bike riders. On the basis of this use,
managers reported concerns and impacts related to the natural resources (degradation of
trails, wilderness), social institutions (safety, education), and social policy (planning, legal
claims); and offered management actions for resolving these problems.
Chiu, L., and L. Kriwoken, L. 2003. Managing Recreational Mountain Biking in Wellington
Park, Tasmania, Australia. Annals of Leisure Research 6(4): 339-61.
This article presents research on both mountain biking and hiking impacts. The study found that
there was no significant difference in impacts from hiking and mountain biking on flat ground.
The study noted that biking impact rapidly increased as the steepness of the trail increased.
Gander, H. and P. Ingold. 1997. Reactions of male alpine chamois (Rupicapra rupicapra) to
hikers, joggers and mountain bikers.-. Biological Conservation 79:107–109.
Experiments conducted in Europe measured alert and escape distances of male chamois grazing
in a pasture near a trail used by hikers, runners, and bikers. Median alert distance was 180
meters, and flight was taken at 103 meters, and these distances were affected by the time of day:
Chamois had a stronger response to bikers and runners late in the morning than they did to
hikers. The experiments, conducted from June to October 1993, caused the chamois to use the
pasture less overall.
Goeft, U, and Alder, J. 2001. Sustainable Mountain Biking: A Case Study from the Southwest of
Western Australia." Journal of Sustainable Tourism 9(3): 193-211.
The Environmental impact from mountain biking is analyzed in order to properly assess and
design trails in southwestern Australia. Soil compaction, trail widening, and changes in
vegetation cover was monitored for one year. The goal of this study was to compare short and
long-term effects of riding in the summer and winter months.
20
Heer, C., Rusterholz, H., and Baur, B. 2003. Forest Perception and Knowledge of Hikers and
Mountain Bikers in Two Different Areas in Northwestern Switzerland. Environmental
Management 31(6): 709-23.
Vegetation and wildlife were considered to further assess the impacts of mountain bikers and
hikers. 239 hikers and 126 mountain bikers were interviewed to gauge their knowledge of the
impact recreational activities like mountain biking have on flora and fauna.
Herrero, J. and Herrero, S. 2000. Management Options for the Moraine Lake Highline Trail:
Grizzly Bears and Cyclists. Unpublished report for Parks Canada.
This was a study conducted in Banff National Park, Canada, of grizzly bear reactions to
mountain bikers in the area. Research showed that bears dislike the surprise inherent of the fast-
moving bikers, and are more likely to be dangerous at closer distances, which is also inherent of
mountain bikers.
Lathrop, J. 2003. Ecological Impacts of Mountain Biking: A Critical Literature Review.
Wildlands CPR. 29. Retrieved on February 23, 2010 from:
http://www.wildlandscpr.org/ecological-impacts-mountain-biking-critical-literature-review>.
This article looks into the literature that can be found on the impacts of trails by mountain biking.
It then goes into look at some of the research, its strengths and limitations. The article concludes
with research needs.
Marion, J. and Leung, Y. Trail resource impacts and an examination of alternative assessment
techniques. Journal of Park and Recreation Administration. 19(3): 17-37.
This article covers different types of trail impacts, including from biking, and discusses various
types of assessments, such as inventory, maintenance, and condition. It includes a comparison of
point samples in Great Smoky Mountains to illustrate point sampling importance in trail
maintenance, and problem assessment discussion to determine predetermined issues that appear
on trails.
Parsons, D. 2002. Understanding and Managing Impacts of Recreation Use in Mountain
Environments. Arctic, Antarctic, and Alpine Research, 34(4): 363-364. Retrieved on
September 23, 2010 from: http://www.jstor.org/stable/1552193
This article presents many recreational activities that create impacts in mountain environments.
Hiking, skiing, snowshoeing, mountain biking, backpacking, fishing, and hunting are all
included along with the impact they create. Many recreational activities done in mountainous
areas are done in the winter. The author makes suggestions regarding management and activity
designation.
21
Pickering, C., Hill, W., Newsome, D., and Leung, Y. 2010. Comparing hiking, mountain biking,
and horse riding impacts on vegetation and soils in Australia and the United States of America.
Journal of Environmental Management, 91(3): 551-562.
Along with analyzing soil and vegetation impacts from horses and hikers, this article addresses
the impact of mountain biking. Skidding from taking sharp turns is analyzed, along with the
impact from mountain bikers constructing new trails, jumps, and bridges. There is a possibility
of these activities spreading weeds and plant pathogens. The article explains proper management
techniques when concerning mountain biking and plant life.
Reader, R. and Thurstron, E. 2001. Impacts of Experimentally Applied Mountain Biking and
Hiking on Vegetation and Soil of a Deciduous Forest. Environmental Management 27(3): 397-
409.
Many recent trail degradation problems have been attributed to mountain biking because of its
alleged capacity to do more damage than other activities, particularly hiking. This study
compared the effects of experimentally applied mountain biking and hiking on the understory
vegetation and soil of a deciduous forest. Five different intensities of biking and hiking (i.e., 0,
25, 75, 200 and 500 passes) were applied to 4-m-long × 1-m-wide lanes in Boyne Valley
Provincial Park, Ontario, Canada. Measurements of plant stem density, species richness, and soil
exposure were made before treatment, two weeks after treatment, and again one year after
treatment. Biking and hiking generally had similar effects on vegetation and soil. These results
indicate that at a similar intensity of activity, the short-term impacts of mountain biking and
hiking may not differ greatly in the undisturbed area of a deciduous forest habitat. The
immediate impacts of both activities can be severe but rapid recovery should be expected when
the activities are not allowed to continue. Implications of these results for trail recreation are
discussed.
Ruff, A. and Mellors, O. 1993. The Mountain Bike - the dream machine? Landscape Research
18(3): 104-109. Retrieved on September 7, 2010 from:
http://www.informaworld.com/smpp/content~db=all ~content =a769325371.
This paper examines the development of recreation on mountain bikes, since they were
introduced in 1983. It considers some of the social conflicts that have reportedly arisen and then
presents the results of a user survey undertaken in 1992. This provides a profile of mountain bike
use and users. The aim of the study is to provide landscape managers, planners etc., with basic
information about this latest form of countryside recreation so as to encourage more effective
provision and management.
22
Symmonds, M., Hammitt, W., and Quisenberry, V. 2000. Managing Recreational Trail
Environments for Mountain Bike User Preferences. Environmental Management 25(5): 549-564.
This study focuses on environmental factors of recreational environments that are primarily used
by mountain bikers. Little research has been conducted on the social carrying capacity of
mountain biking environments, relative to the amount of physical and biological capacity
research that has been conducted. The objective of this study was to further resource
management knowledge of the mountain bike user in order to better incorporate social carrying
capacity into the management of bike use environments. Data gathered from bikers highlight
some important issues concerning the design and management of wildland recreation
environments that are primarily used for mountain biking. These findings were used to address
questions that resource managers should consider when striving to effectively manage wildland
recreation areas primarily used for mountain biking.
Wilson, J., and Seney, J. 1994. Erosional Impact of Hikers, Horses,Motorcycles, and Off-Road
Bicycles on Mountain Trails in Montana. Mountain Research and Development 14(1): 77-88.
This study examined the relative impacts of hikers, horses, motorcycles, and off-road bicycles in
terms of water runoff and sediment yield from 108 sample plots on existing trails in Montana.
Treatments of 100 passes were carried out to each plot. The test took into account the different
variables that may contribute to runoff and sediment yield such as; slope, soil texture, soil
moisture, and soil roughness. It was found that horses and hikers made more sediment available
than wheels from motorcycles and bicycles and that this effect was most noticeable and severe
and trails that were wet before the trampling began. The results also pointed toward the need for
more research to examine higher intensities of use, of more than just 100 tramples.
23
Snowmobile Use
Bishop, G. A., R. Stadtmuller, D. H. Stedman, and J. D. Ray. 2007. Portable Emission
Measurements of Snowcoaches and Snowmobiles in Yellowstone National Park. Study
completion report. Retreived on September 1, 2010 from
http://www.nps.gov/yell/parkmgmt/upload/YNP_2006_snowcoach_snowmobile_study.pdf
The University of Denver carried out a ten day, winter emissions collection program in
Yellowstone National Park that concentrated on measuring the in-use emissions from
commercial snowcoaches and snowmobiles operating out of the town of West
Yellowstone, MT. Between January 25 and February 3, 2006 we instrumented ten
snowcoaches and two snowmobiles with a portable emissions analyzer and collected
approximately 22 hours of emissions and vehicle activity data.
Carroll, J. N., and J. J. White, Characterization of Snowmobile Particulate Emissions, SAE
International Technical Papers. Retrieved on September 1, 2010 from:
http://papers.sae.org/2000-01-2003.
This study compared a four-stroke to a two-stroke snowmobile engine. Data were collected in a
laboratory setting. The engines were tested using a 5-mode steady-state snowmobile engine test
cycle that was developed for the International Snowmobile Manufacturers Association by the
Southwest Research Institute. The experiments were all conducted indoors with just the engine.
The study concluded that two-stroke snowmobile emissions are composed primarily of volatile
organics compounds, which are lubricant derived. Results revealed that more than 99 percent of
the particles were ultrafine (Dp<100nm), with a peak concentration in the nanoparticle
(Dp<50nm) size range. It was also observed that the use of a biosynthetic lubricant increased
both volatile and total PM mass emissions compared to the mineral lubricant. Bioassay results
showed that snowmobile particulate is mutagenic.
Creel, S., Fox, J., Hardy, A., Sands, J., Garrott, B., and Peterson, R. 2002. Snowmobile Activity
and Glucocorticoid Stress Responses in Wolves and Elk. Conservation Biology 16: 3 809-814.
Fecal glucocorticoid levels for wolves and elk were tested to see if increased levels occurred in
areas where there were high levels of snowmobile activity. Fecal glucocorticoid levels were
higher in wolves in areas and times of heavy snowmobile use. Also for elk, glucocorticoid levels
were higher in response to snowmobiles. Despite these stress responses, there was no evidence
that current levels of snowmobile activity are affecting the population dynamics of either species
in study locations.
24
Dorrance, M.J., Savage, P.J., and Huff, D.E. 1975. Effect of snowmobiles on white-tailed deer.
Journal of Wildlife Management 39: 563-569.
This study determined that deer respond to very low intensities of intrusion by humans and
vehicles. The number of deer along trails decreased as snowmobile traffic increased. Even light
snowmobile use caused deer displacement from areas immediately adjacent to the trails. Further
snowmobile traffic caused no additional response. Deer returned within hours after snowmobile
use stopped.
Eckstein, R.G., O’Brien, T.F., Rongstad, O.J., and Bollinger, J.G. 1979. Snowmobile effects on
movements of white-tailed deer: A case study. Environmental Conservation 6:45-51.
This study reports on the effects of snowmobile disturbance on deer in winter deer yards. No
significant effects were found on overall movement of deer with regard to home ranges and
habitat use. Disturbance did cause deer movement during a normally dormant period at night.
Snowmobile disturbance caused deer to move away from the trail and this effect was most
pronounced within 61 meters of the trail. The study recommended that trails be routed away
from winter deer yards.
Ingersoll, G. 1999. Effects of snowmobile use on snowpack chemistry in Yellowstone National
Park, 1998. U.S. Geological Survey Water-Resources Investigations Report 99-4148, 23pp.
http://pubs.usgs.gov/wri/wri994148/pdf/wrir99-4148.pdf
Snowpack samples representing most of the winter precipitation were collected at about the
time of maximum annual snow accumulation at a variety of locations in and near the park to
observe the effects of a range of snowmobile traffic levels. Concentrations of organic and
inorganic compounds in snow samples from pairs of sites located directly in and off snow-
packed roadways used by snowmobiles were compared. Concentrations of ammonium were up
to three times higher for the in-road snow compared to off-road snow for each pair of sites. Thus,
concentrations decreased rapidly with distance from roadways. In addition, concentrations of
ammonium, nitrate, sulfate, benzene, and toluene in snow were positively correlated with
snowmobile use.
Kolbe, J.A., J.R. Squires, D.H. Pletscher, & L.F. Ruggiero. 2007. The Effect of Snowmobile
Trails on Coyote Movements Within Lynx Home Ranges. The Journal of Wildlife Management,
71: 5 1409-1418.
Researchers investigated how coyotes interacted with compacted snowmobile trails by
conducting carnivore track surveys and by snow tracking adult coyotes in areas of western
Montana, USA, with both documented lynx presence and recreational snowmobile use. Coyotes
used compacted forest roads and uncompacted forest roads similarly. Coyotes did not travel
closer to compacted snowmobile trails than random expectation and the distance they traveled
from these trails did not vary with daily, monthly, or yearly changes in snow supportiveness or
25
depth. However, they strongly selected for naturally shallower and more supportive snow
surfaces when traveling off compacted snowmobile trails. Coyotes were primarily scavengers in
winter and did not forage closer to compacted snowmobile trails than random expectation. The
overall influence of snowmobile trails on coyote movements and foraging success during winter
appeared to be minimal on our study area. The results of this study will allow land managers to
better assess the effects of snow-compacting activities on coyotes and lynx.
Kreag, G. "Minnesota’s North Shore Snowmobile Trail: What is its Value?." Minnesota Sea
Grant. Sea Grant, Retrieved on February 24, 2010 from:
http://www.seagrant.umn.edu/recreation/snowmobile.
This article explores a specific trail in Minnesota and its value. There are economic values for
the trail; snowmobiling in Minnesota is a 300 million dollar industry. In Minnesota, a
disproportionate amount of snowmobilers reside in the north part of the state due to reliable trail
conditions. The North Shore Trail is a 235 mile trail between Duluth and Grand Marias. This
trail is also used by snowshoers, horseback riders, skiers and mountain bikers. The snowmobile
trail has regional economic effects, attracting people from out of state and from other parts of the
state. The article goes on to calculate that the amount of money people spend on the trail is above
two million dollars in 1994. Other expenditures are also discussed. The author comes to the
conclusion that along with the economics the effects felt on the residents of the area will also be
felt in areas such as noise pollution, air pollution and wildlife disruption.
McCarthy, F. 2008. "The Impact of Snowmobiles on the Bridger-Teton National Forest:
Considerations for Winter Travel Plans." The Wyoming Wilderness Association. Retreived on
September 2, 2010 from:
http://www.wildwyo.org/NationalForest/BridgerTetonNF/btnfsnowmobiles.htm
Over the past two decades a significant increase in the popularity of snowmobiling and
improved technology has greatly expanded the reach of snowmobiles and their associated
environmental impacts. Snowmobiles are multiple impact machines that damage air and
water quality, area wildlife, natural peace and quiet, public health, and visitor safety. This
report is intended to educate the reader on the environmental impacts of snowmobiling, the
level of use occurring with Bridger-Teton National Forest, and the legal considerations of
managing snowmobiling. While research on the environmental impacts of snowmobiling has
been ongoing for over forty years, the recent controversy over snowmobiling in neighboring
Yellowstone National Park has generated new information. This data is condensed in this
report along with relevant research from other regions. The legal implications of these
impacts are reviewed. By summarizing this large body of information on the environmental
impacts of snowmobiles and associated legal considerations, it is hoped that personnel at the
Bridger-Teton National Forest will be better equipped to protect natural resources and uphold
federal laws.
26
Millner, J. Snowmobiles in Yellowstone National Park: An American right, or
wrong?." Exploring the Yellowstone Ecosystem. Montana State University, Retrieved on
February 24, 2010 from
http://serc.carleton.edu/research_education/yellowstone/snowmobiles.html.
This article looks at the history, debate and effects of snowmobiles in Yellowstone
National Park. Snowmobiles were first allowed in the park in 1963. Since that time they
have been a source of controversy. One of the concerns is that snowmobiles cause a lot of
pollution since most snowmobiles use two stroke engines which burn the lubrication oil as
well as gas. Studies have also been done on snow chemistry and water quality impact in
regards to snowmobiles. Another major concern is impacts on wildlife as well as noise
level and economic impacts. There are several alternatives and solutions out there which
this article talks briefly about as well.
Moen, A. N. 1976. Energy conservation by white-tailed deer in the winter. Ecology, 57:192-198.
This study of white-tailed deer found that energy may be conserved by reducing the general level
of activity, seeking more level land, lesser snow depths and walking slowly. Such measures may
save up to 1000 kcal/day/60 kg deer. The study concluded that deer in winter should remain
undisturbed and that dog harassment and snowmobile traffic is detrimental.
Moen, A. N., Whittemore, S. and Buxtin, B. 1982. Effects of disturbance by snowmobiles on
heart rate of captive white-tailed deer. New York Fish and Game Journal 29:176-183.
This study of captive white-tailed deer found that the deer exhibited heart rate increases
averaging 2.5 times pre-stimulus rates when snowmobiles moved tangentially and 2.9 times
when deer were circled. This study also found that habituation did not occur when these
disturbances were repeated.
Morris, J.A. 1999. Real-time Remote Sensing of Snowmobiles Emissions at Yellowstone National
Park: An Oxygenated Fuel Study, 1999. Retrieved on September 2, 2010 from:
http://pubs.usgs.gov/wri/wri994148/pdf/wrir99-4148.pdf.
The University of Denver conducted a study of snowmobile emissions remotely. The researchers
were calculating the percentage of hydrocarbon, carbon monoxide and toluene to CO2. From that
they could calculate grams per mile, gallons etc. Measurements were made at the West Entrance,
South Entrance and west exit of Yellowstone. The distribution of CO2 was consistent with
automobiles. In areas where the snowmobiles used ethanol there was a decrease in temperature
compared with the areas where regular fuel was used. Aromatics were also measured at the West
entrance and a correlation was made that the higher the hydrocarbon emissions were the higher
the toluene (aromatic) emissions were.
27
Musselman, R., and Korfmacher, J. 2007. Air quality at a snowmobile staging area and snow
chemistry on and off trail in a Rocky Mountain subalpine forest, Snowy Range, Wyoming.
Environmental Monitoring & Assessment 133: 321-334.
A study was begun in the winter of 2000–2001 and continued through the winter of 2001–2002
to examine air quality at the Green Rock snowmobile staging area at 2,985 m elevation in the
Snowy Range of Wyoming. The study was designed to evaluate the effects of winter recreation
snowmobile activity on air quality at this high elevation site by measuring levels of nitrogen
oxides (NO x , NO), carbon monoxide (CO), ozone (O3) and particulate matter (PM10 mass).
Snowmobile numbers were higher weekends than weekdays, but numbers were difficult to
quantify with an infrared sensor. Nitrogen oxides and carbon monoxide were significantly higher
weekends than weekdays. Ozone and particulate matter were not significantly different during
the weekend compared to weekdays. Air quality data during the summer was also compared to
the winter data. Carbon monoxide levels at the site were significantly higher during the winter
than during the summer. Nitrogen oxides and particulates were significantly higher during the
summer compared to winter. Nevertheless, air pollutants were well dispersed and diluted by
strong winds common at the site, and it appears that snowmobile emissions did not have a
significant impact on air quality at this high elevation ecosystem. Pollutant concentrations were
generally low both winter and summer. In a separate study, water chemistry and snow density
were measured from snow samples collected on and adjacent to a snowmobile trail. Snow on the
trail was significantly denser and significantly more acidic with significantly higher
concentrations of sodium, ammonium, calcium, magnesium, fluoride, and sulfate than in snow
off the trail. Snowmobile activity had no effect on nitrate levels in snow.
National Park Service. 2009. Report on Wildlife Responses to Motorized Winter Recreation in
Yellowstone. Yellowstone National Park: Wyoming. Retrieved on September 3, 2010 from:
http://www.nps.gov/yell/parkmgmt/upload/2008wildlife_final.pdf
This report describes the responses of wildlife to snowmobiling activities throughout the park
during the winter of 2008. The study used common recreationist behavior while observing the
reactions of several different types of wildlife such as bison, elk, trumpeter swans, coyotes, bald
eagles, wolf, golden eagle, and bobcat.
Neumann, P.W. and Merriam, H.G. 1972. Ecological effects of snowmobiles. Canadian Field
Naturalist 86: 207-212.
This study reported that temperature gradients were decreased due to snow compaction which
resulted in increased metabolic demand by organisms in subnivean environments. Increased
snow density could result in increased energy costs of burrowing animals. This study also found
that snowshoe hare activity decreased significantly within 76 meters of snowmobile trails, while
red fox activity increased near trails.
28
Ray, J. 2007. Results from Yellowstone National Park Winter Air Quality Study: 2006-2007.
National Park Service, Air Resources Division, Denver, Colorado. Retrieved on September 23,
2010 from: http://www.nature.nps.gov/air/Pubs/pdf/yell/PreliminaryReportWinter2006-
2007AirQualityYellowstone.pdf
The air quality at both the monitoring stations in Yellowstone National Park remained well
below the national standards for carbon monoxide (CO) and particulate matter that was 2.5
micrometers or less in size (PM2.5). The winter of 2006-2007 had CO values that were nearly
the same as the last few years. The maximum hourly CO at the West Entrance was slightly
higher but the longer averages of 8-hours and for the season were down. The PM2.5 was close to
values seen in the last three years.
Richens, V.B. and Lavigne, G.R. 1978. Response of white-tailed deer to snowmobiles and
snowmobile trails in Maine. Canadian Field Naturalist 92: 334-344.
This study found that most deer followed snowmobile trails for short distances and used them
near major bedding areas. Snowmobile disturbance did not cause deer to abandon preferred
bedding areas and feeding sites. Deer were induced to move up to 1.9 kilometers by use of
snowmobile trails, cedar foliage and chainsaw noise.
Schmid, W.D. 1971. Modification of the subnivean microclimate by snowmobiles. Proceedings
of the Snow and Ice Conferecne. Ames, IA: 251-257.
Mechanical compaction of snow alters the mild subnivean microclimate and leads to
densification of snow. The stress of winter temperatures may increase for organisms living
within or beneath compacted snow. The study showed that heavily used areas had such dense
snow that it is doubtful if any movement by small mammals could occur at the snow/ground
surface and that snow roosting by birds would be impossible. Even lightly used trails might have
sufficient compaction to curtail small mammal movement in the subnivean space.
Sive, B., Shively, D., and Pape, B. 2003. Spatial variation and characteristics of volatile organic
compounds associated with snowmobile emissions in Yellowstone National Park, report, Office
of Planning and Compliance, National Park Service, Washington, D.C. Retrieved on September
3, 2010 from: http://www.nps.gov/yell/parkmgmt/upload/sive_report.pdf
This study was designed to investigate the spatial distribution of volatile organic compounds,
carbon monoxide, and methane associated with oversnow vehicular travel in Yellowstone
National Park. There were over 218 samples taken of air quality testing for various emissions.
The abundance of gases in the Park were also seen to vary spatially. For all gases that are
indicative of 2-stroke emissions, the highest levels were observed in those areas of the Park that
experienced higher levels of traffic.
29
VHP Pioneer and VAST. 2010. Snowpack Chemistry Final Report. Retrieved on September 23,
2010 from:
http://www.uvm.edu/tourismresearch/trails/VAST%20Snowpack%20Chemistry%20Report_Fina
l.pdf
With increased snowmobile usage in the State of Vermont over the past 30 years, concern from a
variety of interest groups has arisen about the potential environmental impacts associated with
the use of snowmobiles on public lands. Little research has been previously conducted to
evaluate the effects of snowmobile traffic on the chemical composition of snowpack, and
therefore, The Vermont Association of Snow Travelers (VAST) requested that VHB Pioneer
conduct a scientific study that investigates whether chemical compound emissions associated
with snowmobiles are impacting snow, soil, and/or water. Snowmelt and runoff chemistry
monitoring indicated no detectable levels of volatile organic compounds or total petroleum
hydrocarbons in surface waters that are located immediately downgradient of the snowmobile
trails that were evaluated. These data indicate that the snowmobile usage during the 2009/2010
season did not have any impact on the surface water quality in the vicinity of heavily used
snowmobile trails.
Welsh, T. 2003. The Impacts of Snowmobiling and Cross-Country Skiing on Ungulates.
Wildlands CPR: Reviving Wild Places. Retrieved on February 23, 2010 from:
http://www.wildlandscpr.org/node/215.
Across the United States, outdoor recreation continues to rise in popularity while wildlife habitat
continues to shrink. These converging trends increase the potential for negative human-wildlife
interactions and make it imperative that society recognize how recreation affects wildlife (Knight
and Temple 1995). This article reviews the literature concerning the impacts of snowmobiling
and cross-country skiing on ungulates, and comments on the limitations of this research.
White, J. and Carroll, J. (1998). Emissions from Snowmobile Engines Using Bio Based Fuels and
Lubricants. Retrieved on September 3, 2010 from:
http://www.deq.state.mt.us/CleanSnowmobile/publications/Reports/pdf/EmissionsfromSnowmob
ileEngines.pdf
Snowmobile engine emissions are of concern in environmentally sensitive areas, such as
Yellowstone National Park. A program was undertaken to determine potential emission benefits
of use of bio-based fuels and lubricants in snowmobile engines. Candidate fuels and lubricants
were evaluated using a fan-cooled 488-cc Polaris engine, and a liquid-cooled 440-cc Arctic Cat
engine. Fuels tested include a reference gasoline, gasohol (10% ethanol), and an aliphatic
gasoline. Carburetor jets were not changed between fuels. Lubricants evaluated include a bio-
based lubricant, a fully synthetic lubricant, a high polyisobutylene lubricant, as well as a
conventional, mineral-based lubricant. Emissions and fuel consumption were measured using a
five-mode test cycle that was developed from analysis of snowmobile field operating data.
Emissions measured include total hydrocarbons, carbon monoxide, nitrogen oxides, carbon
30
dioxide, particulate matter, polycyclic aromatic hydrocarbons, individual hydrocarbon species,
ammonia, and sulfur dioxide.
31
Off-Highway Vehicle (OHV) Use
Anderson, Alan B., Paul D. Ayers, Patricia Sullivan, and William R. Ochsner. 2007. Vehicle
Impacts on Vegetation Cover at Camp Atterbury, Indiana: Part 2. Predicting Impacts of Untested
Vehicles." Indiana Academy of Science 116: 139-47. Retrieved on May 8, 2010 from
http://www.indianaacademyofscience.org/Documents/Proceedings/V116/Proc_v116_2_2007_pp
139-147.aspx
Vehicle tracking systems were installed on four military vehicles at Camp Atterbury, Indiana to
assess the impact of tracking by these vehicle types on vegetation loss. Vegetation loss was
recorded immediately after tracking. Results from our study indicate that vehicle impact data and
models can be applied to untested vehicles and reasonably estimate vegetation loss at Camp
Atterbury. The ability to estimate site impacts of untested vehicles allows installation natural
resources personnel to more accurately assess proposed land management actions in a timely and
economical manner.
Barton, Daniel C., Holmes, Aaron L. 2007. Off-Highway Vehicle Trail Impacts on Breeding
Songbirds in Northeastern California. Journal of Wildlife Management Vol. 71.5, pp. 1617-1620.
Rapid growth in off-highway vehicle (OHV) use in North America leads to concerns about
potential impacts on wildlife populations. The authors studied the relationship between distance
to active OHV trail and songbird nesting success and abundance in northeastern California,
USA, from 2002 to 2004. They found evidence of greater nest desertion and abandonment and
reduced predation on shrub nests <100 m from OHV trails than at nests >100 m from OHV
trails. Two of 18 species studied were less abundant at sites on trails than at sites 250 m from
trails, and no species were more abundant on trails. Management of OHV trail development
should consider possible negative impacts on nesting success and abundance of breeding birds.
Blionis, G. J., and Woodin S. J. 1999. Vehicle Track Damage to Salt Marsh Soil and Vegetation
at Culbin Sands, NE Scotland. Botanical Journal of Scotland 51.2: 205-21.
The effects of 3 year old vehicle tracks on salt marsh soil and vegetation within Culbin Sands
SSSI on the Moray Firth, Scotland were investigated. Vehicle tracks destroyed the organic layer
which was present in the later successional communities. Soil penetration resistance and bulk
density were increased, and moisture content and salinity were decreased inside all the tracks,
thus soil characteristics were shifted towards those typical of lower marsh zones. Penetration
resistance within tracks reached levels which may inhibit root elongation. Vegetation inside
tracks remained in earlier successional stages than the surrounding communities, particularly on
the lower marsh where recovery may be slowed by repeated disturbance by tidal water.
Vegetation on the mid and upper marsh showed less successional shift, but was still changed,
being more diverse within the tracks. There was also a significant amount of bare ground within
these tracks, which could facilitate erosion. Effects of vehicle tracks thus vary between salt
marsh zones, but are damaging wherever they occur; there appears to be no 'less damaging' route
on which vehicles could be directed.
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Boyle, Stephen A. and Samson, Fred B. 1985. Effects of Nonconsumptive Recreation on
Wildlife: A Review. Wildlife Society Bulletin 13: 110-116. Retrieved on September 1, 2010
from: http://www.jstor.org/stable/3781422.
This article focuses on participation of non-consumptive outdoor recreation. Due to the increase
of recreation in the past 20 years the evaluators have to focus on the impact of the wildlife and
the wildlife habitat. A review of the literature was undertaken with the hope that there will be a
better understanding of the relationship between wildlife disturbance and recreationist behavior.
Mechanized forms of recreation have the most serious impacts, however, even casual incursions
by recreationist on foot can disturb wildlife.
Buck, B. and Goossens, D. 2009. Dust Dynamics in Off-road Vehicle Trails; Measurements on
16 Arid Soil Types, Nevada, USA. Journal of Environmental Management Vol. 90.11, pp.
3458-3469.
Soil analyses and measurements with the Portable In Situ Wind Erosion Laboratory were
conducted on 16 soil types in an area heavily affected by off-road vehicle (ORV) driving.
Measurements were performed in ORV trails as well as on undisturbed terrain to investigate how
ORV driving affects the vulnerability of a soil to emit PM10 (particles<10microm), during the
driving as well as during episodes of wind erosion. Particular attention was paid to how the
creation of a new trail affects those properties of the topsoil that determine its capability to emit
PM10. Also, recommendations are given for adequate management of ORV-designed areas.
Trails in sand show higher deflation thresholds than the surrounding undisturbed soil. Trails in
silt and in drainages, on the other hand, have lower deflation thresholds than undisturbed soil.
The increase in PM10 emission resulting from the creation of a new ORV trail is much higher
for surfaces with silt than for surfaces with sand. The results of this study suggest that, to
minimize emissions of PM10, new ORV fields should preferably be designed on sandy terrain
rather than in silt areas or in drainages.
Environmental Protection Agency. 2002. Environmental Impacts of Newly Regulated Non-road
Engines: Frequently Asked Questions. Office of Transportation and Air Quality. Retrieved on
September 23, 2010 from: http://epa.gov/nonroad/2002/f02033.pdf.
The U.S. Environmental Protection Agency (EPA) has adopted emission standards for
recreational vehicles, recreational marine diesel engines, and industrial spark-ignition engines.
This information sheet addresses questions about the environmental impacts of these engines
and how this regulation will improve air quality.
Foltz, R. and Meadows, D. 2010. Impacts of ATV Traffic on Undesignated. Stream Notes,
Stream System Technology Center. Retrieved on February 23, 2010 from
http://www.stream.fs.fed.us/news/streamnt/apr07/apr00_2.htm.
33
The U.S. Department of Agriculture, Forest Service reports that driving motor vehicles off-road
has become one of the fastest growing activities on national forest lands. The continued growth
and use of all-terrain vehicles (ATVs) has created a demand upon many existing trail systems
that were not designed for this level of use. This has challenged the capacity of trails and the
ability of recreation managers to schedule and perform basic trail assessments and regular
maintenance. The Forest Service performed a study to determine the effects of ATVs on
national forest resources. This article provides a brief summary of the study. The study concludes
that ATV traffic adversely effects natural resources. The study further concludes that all of the
vehicles tested contribute to those effects regardless of the type of ATV or tire type.
Hannaford, M., and Resh, V. 1999. Impact of All-terrain Vehicles (ATVs) on Pickleweed
(Salicornia Virginica L.) in a San Francisco Bay Wetland. Wetlands Ecology and Management
7.4 (1999): 225-33.
Two types of ATVs were tested in Petaluma Marsh, Sonoma Co., California, to determine their
effects on pickleweed. Results indicated that even limited ATV use can cause immediate impact
to pickleweed but that limited use with soft-tread vehicles can recover within a year.
Management of pickleweed wetlands should involve vehicles with non-damaging tracks or tire
tread and, when possible, walking is preferable to reduce immediate habitat damage.
Hosier, P., and Eaton, T. 1980. The Impact of Vehicles on Dune and Grassland Vegetation on a
South-Eastern North Carolina Barrier Beach. Journal of Applied Ecology 17(1) 173-82..
Researchers compared and contrasted vegetation in two barrier beaches in southeastern North
Carolina; one beach had been used for off-road vehicle traffic and the other had not. Vegetation
on the beach with vehicle traffic had had a dramatic decrease in the amount of vegetation than
the other beach tested. The study was done to see how loss of vegetation would increase the
intensity of oceanic over wash at the site.
Foltz, R., and Yanosek, K. 2005. Impacts of all terrain vehicles (ATV) on National Forest lands
and grasslands. Treesearch - Forest Service Research & Development. Retrieved on February
23, 2010from: http://www.treesearch.fs.fed.us/pubs/23518.
The US Forest Service has identified unmanaged all terrain vehicle (ATV) use as a threat to
forested lands and grasslands. Some undesirable impacts include severely eroded soils,
usercreated unplanned roads, disrupted wetland ecosystems, as well as general habitat
destruction and degraded water quality throughout forested lands. More insight on how ATV use
affects trails is needed in order to make management decisions concerning ATV use on National
Forest lands. Factors which may determine impacts of ATVs include site characteristics, such as
soil moisture, soil types, existing terrain, and storm events, and ATV attributes such as vehicle
type, tire tread, amount of trail use, and rider attitude.
34
Kucera, E. 1976. Deer flushing distance as related to observer’s mode of travel. Wildlife Society
Bulletin 4: 128-129.
This study reported that the mean flushing distance for deer varied by the observer’s mode of
travel. The mean flushing distance was 122 meters when the observer was on foot, 97 meters
when the observer was on horseback, and 82 meters when the observer was in a vehicle. About
75% of deer studied allowed observers in vehicles or on horseback to approach within 100
meters, while only 50% allowed observers on foot to do so.
Luckenbach, R., and Bury, B. 1993. Effects of Off-Road Vehicles on the Biota of the Algodones
Dunes, Imperial County, CA. Journal of Applied Ecology 20(1) pp. 265-86.
The Algodones Dunes, contains many unique species. The system also receives the greatest use
by ORVs. The finding of this study demonstrate that ORV activity in these dunes are highly
detrimental to dune organisms, both flora and fauna. The desert-kangaroo rat and fringe-toed
lizard populations are severely reduced in area where ORV recreation is frequent. In these ORV
area arthropods were also found at a less frequent rate. The total numbers of vertebrate species
sampled in the plots were positively correlated with the perennial vegetation, and since volume
of vegetation is decreased in relation to ORV use the authors conclude that even minor levels of
ORV use can cause a reduction in the species found in the dune ecosystems.
Harrison, R., Makel, W., and Besse, L. 1993. Sound Levels of Five Motorcycles Traveling Over
Forest Trails. Department of Technology and Development USFS. Retrieved on September 2,
2010 from http://www.fs.fed.us/t-d/pubs/pdfimage/93231802.pdf.
Sound generated from five different ORVs was studied. One of the most overlooked effects of
ORVs and OHVs is sound and how far it travels. The sound was measured in the forests trail of
ORV areas in Rock Creek ORV area. The results showed that motorcycles that followed CA
guidelines for decibels were not able to be heard over 400 ft away, while motorcycles that were
not in compliance with these regulations were able to be heard from a half a mile. There were no
direct effects on wildlife from the motorcycle sound.
Marsh, J., and Warfield, J. 1997. Ganaraska Forest Trails Project: Final Report. Trail Studies
Unit, Trent University, Peterborough, Ontario Canada. 68 pages. Retrieved on September 9,
2010 from: http://oftr.ca/files/81/Ganaraska_Trails_Project.pdf.
The Ganaraska Trails Project was initiated in 1996, in response to concerns and debate about the
recreational use of trails, and the environmental impacts and conflicts associated with such use in
the Ganaraska Forest. The report defines the Forest as the study area. Next there is a brief history
of recreational ussues and management responses to them. The research methods used included
literature review, remeasurement of the existing trails, measurement of trail conditions, a mail
survey of forest members, interviews with recreationists, interviews with representatives of user
groups, and local residents. The purpose of the project was to determine the characteristics,
35
behaviors and attitudes of recreationists, analyze the impacts of their activities on the
environment, analyze conflict between different users, formulate a set of standards to guide
future management, and suggest management guidelines and actions to ensure standards are
maintained and impacts and conflicts reduced.
Hecht, M., and Griffin, C. 1994. Piping Plover Mortalities Caused by Off-Road Vehicles on
Atlantic Coast Beaches. Wildlife Society Bulletin 22, 409-414.
This article talks about the piping plover and how it is listed as threatened and endangered in the
different coastal states. The authors talk about how the use of off road vehicles may play a role in
reproductive success of the birds. They believe that this is the reasoning behind not allowing
ORVs on the beaches anymore.
Munger, J., Barnett, B., Novak, S., and Adams, A. 2003. Impacts of Off-Highway Motorized
Vehicle Trails on the Reptiles and Vegetation of the Owyhee Front. Technical Bulletin: 3(3) 1-
27.
Researchers used drift fences to trap reptiles near to and far from off road motorized vehicle
trails in the Owyhee Front. They also assessed vegetation. Researchers found that at the less
intensively used OHMV site there was a tendency for more reptiles to be found at
25 m from the trails than at 2 m from the trails. However, at the more intensively used site
there was a tendency for more reptiles to be found at 2 m from the trail than at 25 m, but both
were lower than at 100 m. Native shrubs, bunch grasses, and microbiotic crust were less
prevalent closer to trails and at the more intensively used site. Cheatgrass and Chrysothamnus
spp., both indicative of disturbance, were more prevalent closer to trails and at the more
intensively used site. Researchers ascribe the patterns in reptile density to the effects on
vegetation. Dense cheatgrass prevents movement of reptiles, meaning that in disturbed areas,
OHMV trails offer the only corridors available.
National Off-Highway Vehicle Conservation Council. 2010. NOHVCC Library: Environmental
Impact: Wildlife/Vegetation Effects. Retrieved on September 9, 2010 from:
http://nohvcclibrary.forestry.uga.edu/ei%20wildlife.html.
This website lists many published and unpublished reports and journal articles pertaining to the
effects of OHV use on wildlife and vegetation. Most citations contain links to abstracts, and
some have links to full text versions of the publication.
Naylor, L., Wisdom, M., and Anthony, R. G. (2009). Behavorial Responses of North American
Elk to Recreational Activity. The Journal of Wildlife Management , 328-338.
Off-road recreation on public lands in North America has increased dramatically in recent years.
Wild ungulates are sensitive to human activities, but the effect of off-road recreation, both
motorized and nonmotorized, is poorly understood. Researchers measured responses of elk to
36
recreational disturbance in northeast Oregon, USA, from April to October, 2003 and 2004. Elk
were subjected to 4 types of recreational disturbance: all-terrain vehicle (ATV) riding, mountain
biking, hiking, and horseback riding. Motion sensors inside radiocollars worn by 13 female elk
recorded resting, feeding, and travel activities at 5-minute intervals throughout disturbance and
control periods. Elk fed and rested during control periods, with little time spent traveling. Travel
time increased in response to all 4 disturbances and was highest in mornings. Elk travel time was
highest during ATV exposure, followed by exposure to mountain biking, hiking, and horseback
riding. Feeding time decreased during ATV exposure and resting decreased when we subjected
elk to mountain biking and hiking disturbance in 2003. Our results demonstrated that activities of
elk can be substantially affected by off-road recreation. Mitigating these effects may be
appropriate where elk are a management priority. Balancing management of species like elk with
off-road recreation will become increasingly important as off-road recreational uses continue to
increase on public lands in North America.
New York State Department of Environmental Conservation. 2007. All Terrain Vehicle Policy
Supporting Documentation. Retrieved on September 3, 2010 from:
http://www.dec.ny.gov/docs/lands_forests_pdf/draftatvsupdoc2.pdf.
This Supporting Documentation sets forth facts relied upon in developing the Department’s
policy for Public ATV Use on State Forest Lands and Conservation Easements Managed by
the Department of Environmental Conservation. These facts fall into six categories: 1) ATV
Characteristics; 2) Natural Resource Impacts; 3) Illegal Use; 4) Enforcement Issues; 5) Safety
Concerns; and 6) Recreational User Conflicts.
Payne, G., Foster, J. and Leininger, W. 1983. "Vehicle Impacts on Northern Great Plains Range
Vegetation." Journal of Range Management 36(3) 327-31.
Researchers tested three levels of vehicle impacts (2, 8, and 32 trips over the same tracks) using
a four-wheel drive Chevrolet Blazer with snow and mud tires. They used canopy cover
measurements and observation through photography to gather information. As the number of
trips across the impact site increased, the amount of vegetation decreased. Vegetation loss
happened more rapidly on very-moist soils than on dry soils.
Reynolds, M. 1991. Off-road Vehicle User Knowledge of Environmental Impact in Selected Use
Areas. Journal of Ecology (1991).
This study was designed to look at ORV users in Oklahoma, knowledge of ORVs' impact upon
the environment, and to identify opinions as to whether an adverse impact upon the environment
is an acceptable consequence of ORV use. Another element of this study was to identify opinions
about whether management of ORV use areas should be paid for by the ORV users. A
questionnaire was developed by the researcher and juried by a panel of experts. Subjects were
randomly selected at nine ORV locations in Oklahoma. The results showed that 29% of people
37
were willing to accept adverse effects. The majority of ORV users in Oklahoma do not know that
ORV use has impacts on the environment.
Shanley, Colin S., and Sanjay Pyare. 2011. Evaluating the road-effect zone on wildlife
distribution in a rural landscape. Ecosphere 2:art16. [doi:10.1890/ES10-00093.1]. Retrieved on
April 9, 2011 from: http://www.esajournals.org/doi/full/10.1890/ES10-
00093.1?prevSearch=[all%3A+alaska+moose]&searchHistoryKey=&
The road-effect zone is the area in which ecological effects extend outward from a road.
Dispersed off-highway vehicle (OHV; e.g., four-wheelers and snowmachines) activity on rural
road networks creates a disturbance that reduces the effective amount of wildlife habitat and
therefore has the potential for an extensive road-effect zone. Consequently, land managers must
consider the trade-offs between rural road development and the conservation of habitat for
species of concern. We conducted a spatially-explicit study of moose, Alces alces, occurrence in
relation to rural roads and OHV routes in rural Alaska, U.S.A. We used logistic regression and
AIC model selection criterion to develop resource selection functions (RSFs) for male and
female moose at three spatial scales (250 m, 500 m, and 1000 m) in two seasons (summer and
fall). To evaluate an ecological disturbance threshold from increasing route activity on the
probability of animal occurrence, the RSFs were plotted against an index of route activity
derived from interviews with OHV users, and fit with logarithmic functions. The variable for
route activity improved the fit of RSF models for both sexes at all spatial scales and in both
seasons. A negative relationship was found between moose occurrence and routes or areas in
which routes were in close proximity to primary forage, with the exception of male moose at the
1000-m scale in the fall. Therefore, among the spatial scales of analysis, the road-effect zone for
male moose was determined to be between 500 m and 1000 m, and >1000 m for female moose.
Furthermore, route activity <0.25 km of vehicle travel/km2/day was a threshold value at which
moose sustained a high probability of occurrence (0.60 to 0.91). The results of our study suggest
that the dispersed ecological effect of rural roads and OHV routes should be considered in
transportation and land-management planning efforts. Relatively low levels of vehicular activity
may create extensive road-effect zones for sensitive species.
The Tourism Company. 2009. Economic Benefits Assessment of Motorcycle Trail Riding
Activities of Ontario Households in 2008. Unpublished report. Retrieved on September 9, 2010
from: http://www.nabernet.com//mainfiles/files/3081.pdf.
This report identifies the estimated economic benefits of the motorcycle trail riding activities of
Ontario households during 2008. A three-step methodology was used to derive the estimates of
economic benefits which included a survey of the Ontario Federation of Trail Riders
membership spending activities, an estimate of spending by all Ontario households, and finally
an estimate of economic benefits.
Tull, J., and Brussard, P. 2007. Fluctuating Asymmetry as an Indicator of Environmental Stress
From Off-Highway Vehicles. Journal of Wildlife Management 71(6) 1944-1948.
38
Researchers examined the effect of OHV activity on developmental instability in a
phrynosomatid lizard (i.e., western fence lizard) in the western Great Basin, USA. They
measured fluctuating asymmetry (FA) of bilateral head-scale patterns in populations of lizards at
3 OHV and 3 non–OHV sites. Fluctuating asymmetry was higher at OHV sites relative to non-
OHV sites, supporting the idea that OHV activity can stress wildlife populations. We found FA
to be a good tool for uncovering responses to stress in natural populations, and we recommend
exploring FA as a means of uncovering developmental instability in other systems that merit
conservation interest
Waever, T., and Dale D. 1978. Trampling Effects of Hikers, Motorcycles and Horses in
Meadows and Forests. Journal of Applied Ecology, 15(2) 451-457.
This study compares the impacts of hiking, motorcycle use and horse use in forested and
meadow areas. The study found that motorcycle and horse impacts were greater than the impacts
that arose from hiking trail use. Motorcycles were most damaging when traveling uphill, while
horses and hikers were most damaging while traveling downhill. The impacts of hiking were
greater in sloped areas and damage was less in grassy areas then in shrubby areas.
Wilkenson, E., and Whitman, A. 2010. Recreation Trails in Maine and New Hampshire: a
Comparison of Motorized and Non-motorized trails. Proceedings of the 2009 Northeastern
Recreation Research Symposium; 2009 March 29 - 31; Bolton Landing, NY. Gen. Tech. Rep.
NRS-P-xx. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern
Research Station Retrieved on September 3, 2010 from:
http://www.manometmaine.org/documents/WilkersonandWhitmanNERRdraft_2010.pdf
According to the U.S. Forest Service, public recreation is one of the four greatest threats to the
health of forestland. To assess the impact of recreation trails on forestlands 112 trail segments
were sampled (55 motorized, 26 non-motorized, 31 non-mechanized) in Maine and New
Hampshire. Data was collected at 11 random points along a trail to evaluate soil erosion and
plant degradation. The data show significant differences in physical parameters among trail types
but past land use, as well as current recreational use, may contribute to these differences.
39
Horseback Riding and Pack Stock Use
Billings, T. 2005. Equestrian Knowledge of Impacts on Trails. Masters Thesis. Retrieved on
September 7, 2010 from: http://digital.library.okstate.edu/etd/umi-okstate-1618.pdf.
This study explored the impacts that pack animals had on wildlife. The study shows that horses
are not as much of a threat to birds as joggers and hikers, although they still are a threat. Horses
are more of a threat on trails to reptiles, rodents, and other terrestrial life forms. The reason
being, that horses rarely, but sometimes step on these types of wildlife.
Blahna, D., Smith, K., and Anderson, J. 1995. Backcountry Llama Packing: Visitor Perceptions
of Acceptability and Conflict. Leisure Science,.17 185-204. Retrieved on May 6, 2010 from:
http://www.leopold.wilderness.net/pubs/276.pdf.
Pack animal use has very little research pertaining to the impacts environmentally as well as
socially. This article presents the social conflicts that can arise between traditional backcountry
hikers and llama packers. It encourages education on pack animal use to traditional users so
prejudice does not take an affect.
Campbell, J., and Gibson, D. 2001. The effect of seeds of exotic species transported via horse
dung on vegetation along trail corridors. Plant Ecology, 157: 23-35 Retrieved May 7, 2010 from:
http://www.jstor.org/stable/20051158.
Vegetation does have an effect on soils, and this research is based on dung and soil samples in
areas of southern Illinois, which were tested for exotic plant seed. Findings include a lower threat
from seeds carried in by horses in that area than originally thought, but the threat does remain in
trail systems open to equine recreationalists.
Cole, D. and McClaran M. United States Department of Agriculture. 1993. Report for Pack stock
in Wilderness: Use, Impacts, Monitoring, and Management. Bob Marshall Wilderness.
This is an in depth report on the effects of pack stock use in Wilderness areas. First the report
talks about the different types of pack stock use: horse, mule, and llama. Then the report
discusses the different types of impacts associated with pack stock travel, such as trampling,
defoliation, animal waste etc. The ways to monitor these impacts is depicted in the next section.
Examples are given of monitoring systems and how to judge the data collected. Then the article
lays down techniques for controlling use of pack stock on trails, including type, amount, or
duration. The report wraps up by defining some existing management examples in Wilderness
areas such as the Bob Marshall Wilderness.
40
Cole, D, and Spildie, D. 1998. Hiker, horse and llama trampling effects on native vegetation in
Montana, USA. Journal of Environmental Management, 53(1): 61.
The purpose of this study was to assess the relative impact of hiker, horse and llama traffic on
vegetation and groundcover conditions. Hiker, horse and llama traffic were applied at two
trampling intensities (25 and 150 passes at one time) to two previously undisturbed forested
vegetation types (one with an understory dominated by erect forbs, the other dominated by low
shrubs). Trampling effects were assessed immediately after traffic application and 1 year later.
For most impact parameters, intensity of trampling impact varied with type of user. For all
parameters that varied with type of user: (1) horse traffic caused the most disturbance; and (2)
hiker and llama impacts could not be differentiated statistically. The forb-dominated vegetation
type was highly vulnerable to vegetation impact but recovered rapidly. The shrub-dominated
type was more resistant but lacked resilience. Higher trampling intensities caused more
disturbance but the relationship between trampling intensity and disturbance intensity was non-
linear.
DeLuca, T., Patterson, W., Freimund, W., and Cole, D. 1998. Influence of llamas, horses, and hikers
on soil erosion from established recreation trails in western Montana, USA. Environmental
Management 22(2): 255-262. Retrieved February 22, 2010 from:
http://leopold.wilderness.net/pubsResults.cfm?searchType=Publication&Pub=596.
The purpose of this study was to assess the relative physical impact of hikers, llamas, and horses
on recreational trails. Horse, llama, and hiker traffic were applied to 56 separate plots on an
existing trail at Lubrecht Experimental Forest in western Montana. The traffic was applied to
plots at intensities of 250 and 1000 passes along with a no-traffic control under both prewetted
and dry trail conditions. Horse traffic consistently made more sediment available for erosion
from trails than llama, hiker, or no traffic when analyzed across wet and dry trail plots and high
and low intensity traffic plots. Although total runoff was not significantly affected by trail user,
wet trail traffic caused significantly greater runoff than dry trail traffic. Llama traffic caused a
significant increase in sediment yield compared to the control, but caused erosion yields not
significantly different than hiker traffic. Trail traffic did not increase soil compaction on wet
trails. Traffic applied to dry trail plots generally resulted in a significant decrease in soil bulk
density compared to the control. Decreased soil bulk density was negatively correlated with
increased sediment yield and appeared to result in increased trail roughness for horse traffic
compared to hiker or llama traffic. Differences described here between llama and horse traffic
indicate that trail managers may want to consider managing packstock llamas independent of
horses.
41
Törn, A., Tolvanen, A., Norokorpi, Y., Tervo, R., and Siikamäki, P. 2009. Comparing the impacts of
hiking, skiing and horse riding on trail and vegetation in different types of forest. Journal of
Environmental Management, 90(3), 1427-1434.
This paper reports results from a comparison of the impacts of hiking, cross-country skiing and
horse riding on trail characteristics and vegetation in northern Finland. Widths and depths of
existing trails, and vegetation on trails and in the neighbouring forests were monitored in two
research sites during 2001 and 2002. Trail characteristics and vegetation were clearly related to
the recreational activity, research site and forest type. Horse trails were as deep as hiking trails,
even though the annual number of users was 150-fold higher on the hiking trails.
Simultaneously, cross-country skiing had the least effect on trails due to the protective snow
cover during winter. Hiking trail plots had little or no vegetation cover, horse riding trail plots
had lower vegetation cover than forest plots, while skiing had no impact on total vegetation
cover. On the other hand, on horse riding trails there were more forbs and grasses, many of
which did not grow naturally in the forest. These species that were limited to riding trails may
change the structure of adjacent plant communities in the long run. Therefore, the type of
activities undertaken and the sensitivity of habitats to these activities should be a major
consideration in the planning and management of nature-based tourism. Establishment of
artificial structures, such as stairs, duckboards and trail cover, or complete closure of the site,
may be the only way to protect the most sensitive or deteriorated sites.
Wells, F. and Lauenroth, W. 2007. The Potential for Horses to Disperse Alien Plants Along
Recreational Trails. Rangeland Ecol Management. 60. Retrieved on September 7, 2010 from:
http://www.backcountryhorse.com/pdffiles/WellsandLauenrothJREMproof2007.pdf.
The objective of this study was to characterize the potential for long-distance transport of plant
species in the digestive tract of horses along recreational trails. Researchers sampled horse dung
along the first 4 000 m of the Lower Piney River trail in the White River Forest of western
Colorado. They evaluated the seed content of each sample by applying standard methods for soil
seed bank analysis. Researchers found 20 species and 564 seedlings. Twelve of the species were
graminoids, 6 were forbs, 1 was a shrub, and 1 was a tree. The species were evenly divided
between natives and aliens, but 85% of the seedlings were aliens. An average of 47 seedlings
emerged per sample, but the range was from 4 to 192. The results make it clear that horses, and
very likely all pack stock used on recreational trails, represent a potentially important dispersal
vector for alien plants into western wildlands.
Williams, B. (1998). Horses in ecological reserves. American Trails. Retrieved on February 23,
2010, from: http://www.americantrails.org/resources/wildlife/WildEQclemson.html
This article examines the impacts we see on the trails including erosion, sedimentation, carrying
capacity related to experience, resource damage, and non-native species. They concluded that
Federal and State agencies should improve management on these reserves including trail
maintenance and construction. They suggest that Federal and State regulators should establish
carrying capacities for ecological reserves and propose user fees.