This document contains citations and abstracts of the most up-to-date research on the impacts of ORVs on the environment. This is a compilation of ORV research published since 2000, categorized according to resource affected with key findings underlined.
General Reviews of ORV Impacts
Wildlands CPR, and Wild Utah Project. 2008. Best Management Practices for Off-Road Vehicle Use on Forestlands - A Guide for Designating and Managing Off-Road Vehicle Routes. Edited by, T.A. Switalski and A. Jones. Published by Wildlands CPR, Missoula, MT. 50p.
Abstract: Forest management applies to a diversity of human uses, including the use of motorized vehicles by the public. Best Management Practices (BMPs) provide science-based criteria and standards that land managers follow in making and implementing decisions about human uses and projects that affect our natural resources. BMPs are usually developed based on legal obligations, pragmatic experience, and institutional practices, and should be supported by the best available scientific knowledge. However, while many land management activities rely on established Best Management Practices, until now no BMPs have been developed to manage off-road vehicles (ORVs) on forestlands. These BMPs, based on the best available scientific knowledge, fill this gap of Forestland ORV management. This paper provides Best Management Practices to aid land managers in travel planning or in any decision making process related to off-road vehicle management on forested lands. They are not intended to provide guidance for desert lands, though there may be some applicability across landscapes.
Ouren, D.S., C. Haas, C.P. Melcher, S.C. Stewart, P.D. Ponds, N.R. Sexton, L. Burris, T. Fancher, and Z.H. Bowen. 2007. Environmental effects of off-highway vehicles on Bureau of Land Management lands: A literature synthesis, annotated bibliographies, extensive bibliographies, and internet resources: U.S. Geological Survey, Open-File Report 2007-1353, 225 p. http://www.fort.usgs.gov/products/publications/22021/22021.pdf [1]
Executive Summary: This report and its associated appendixes compile and synthesize the results of a comprehensive literature and Internet search conducted in May 2006. The literature search was undertaken to uncover information regarding the effects of off-highway vehicle (OHV) use on land health, or “natural resource attributes,” and included databases archiving information from before OHVs came into existence to May 2006. Information pertaining to socioeconomic mplications of OHV activities is included as well. The literature and Internet searches yielded approximately 700 peer-reviewed papers, magazine articles, agency and non-governmental reports, and internet websites regarding effects of OHV use as they relate to the Bureau of Land Management’s (BLM) standards of land health. Discussions regarding OHV effects are followed by brief syntheses of potential indicators of OHV effects, as well as OHV-effects mitigation, site-restoration techniques, and research needs.
Davenport, J, and TA Switalski. 2006. Environmental impacts of transport related to tourism and leisure activities. In: The ecology of transportation: managing mobility for the environment, editors: J Davenport and Julia Davenport. Dordrecht, Netherlands: Kluwer Academic Publishers. 333-360.
http://www.wildlandscpr.org/files/uploads/PDFs/d_Switalski_2006_Enviro_impacts_of_transport.pdf [1]
Ministry of Water, Land and Air Protection and Grasslands Conservation Council (MWLAP and GCC). 2004. Best Management Practices for Recreational Activities on Grasslands in the Thompson and Okanagan Basins. Ministry of Water, Land and Air Protection, Victoria, B.C. http://www.bcgrasslands.org/SiteCM/U/D/8E9CD8997E4ED889.pdf [2]
Gaines, W.L., P.H. Singleton, and R.C. Ross. 2003. Assessing the cumulative effects of linear recreation routes on wildlife habitats on the Okanogan and Wenatchee National Forests. Gen. Tech. Rep. PNW-GTR-586. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 79p.
http://www.fs.fed.us/pnw/pubs/gtr586.pdf [3]
We conducted a literature review to document the effects of linear recreation routes on focal wildlife species. We identified a variety of interactions between focal species and roads, motorized trails, and nonmotorized trails. We used the available science to develop simple geographic information system-based models to evaluate the cumulative effects of recreational routes on habitats for focal wildlife species for a portion of the Okanogan and Wenatchee National Forests in the state of Washington. This process yielded a basis for the consistent evaluation of the cumulative effects of roads and recreation trails on wildlife habitats, and identified information gaps for future research and monitoring. We suggest that managers use an adaptive management approach to address wildlife and recreation interactions because of the complexity and uncertainty of these issues.
Gilbert, B.K. 2003. Motorized access on Montana’s Rocky Mountain Front: a synthesis of scientific literature and recommendations for use in revision of the travel plan for the Rocky Mountain Division. The Coalition for the Protection of the Rocky Mountain Front. 35p.
http://www.wilderness.org/Library/Documents/upload/Motorized-Access-on-Montana-s-Rocky-Mountain-Front.pdf
[4]
Havlick, D.G. 2002. No Place Distant: Roads and Motorized Recreation on America’s Public Lands. Foreword by Mike Dombeck. Island Press, Washington, DC.
Stokowski, P.A. and C.B. LaPointe. 2000. Environmental and social effects of ATVs and ORVs: an annotated bibliography and research assessment. School of Natural Resources, University of Vermont. 31p.
http://atfiles.org/files/pdf/ohvbibliogVT00.pdf [5]
Summary: This report provides an annotated bibliography of published research related to the environmental and social effects of ATVs on public and private lands. Citations were gathered in a comprehensive literature review of published research reports and peer-reviewed scholarly writing, and from a review of internet sources. Key findings from the research are synthesized and evaluated, and suggestions for future research are provided. A wide variety of environmental and social impacts are documented in the research 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.
Joslin, G. and H. Youmans, coordinators. 1999. Effects of recreation on Rocky Mountain wildlife: A review for Montana. Committee of Effects of Recreation on Wildlife, Montana Chapter of the Wildlife Society. 307p.
http://www.montanatws.org/chapters/mt/index.cfm?tname=rrmwfull
[6]
Wildlands CPR, The Wilderness Society, et al. 1999. Petition to enhance and expand regulations governing the administration of recreational off-road vehicle use on National Forests. Published by Wildlands CPR, Missoula, MT 188p. http://www.wildlandscpr.org/files/uploads/PDFs/Final_ORV_Petition_revised.pdf [6]
ORV Impacts to Streams
Foltz, R.B. 2006. Erosion from all terrain vehicle (ATV) trails on National Forest lands. The American Society of Agricultural and Biological engineers (ASABE). Paper# 068012. St. Joseph, MI.
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. A study was conducted by the Rocky Mountain Research Station and the San Dimas Technology Development Center to evaluate ATV impacts. Trails were classified into one of three disturbances classes of low, medium, and high, based on loss of litter and vegetation, trail width, and depth of wheel ruts. Following trail condition assessment, rainfall simulations were conducted to measure erosion parameters on each of the three disturbance classes. While infiltration parameters decreased with increased levels of ATV traffic, there was no statistically significant difference among the three classification levels. There was, however, generally a significant difference between undisturbed and the combined disturbed conditions. Similar significant differences existed for interrill erosion. In all cases sediment loss would be expected to increase due to ATV traffic. Information acquired from this study will be used to estimate ATV traffic induced erosion and assist in the managing of ATV use.
Ayala, R.D., P. Srivastava, C.J. Brodbeck, E.A. Carter, and T.P. McDonald. 2005. Modeling Sediment Transport from an Off-Road Vehicle Trail Stream Crossing Using WEPP Model. American Society of Agricultural and Biological Engineers, 2005 ASAE Annual International Meeting, Paper No: 052017.
Abstract: There is a limited information available pertaining to the adverse effects of Off-Road-Vehicle (ORV) use and trail impacts. As a result, this study was initiated in 2003 to (a) quantify water quality impacts of an ORV trail stream crossing through monitoring of total suspended solids, and (b) conduct WEPP (Water Erosion Prediction Project) simulations to determine long-term sediment loads contributed by the ORV trail stream crossing. To collect suspended sediment samples from the ORV trail stream crossing, ISCO6 6700 water samplers were installed. Data was collected from November 2003 through July 2004. During this time suspended sediment samples were collected for three different operational conditions (open, closed, maintenance). When the study began the trail was open to traffic. The trail was then closed to traffic on January 1, 2004 and went through a two-week maintenance regime in early march. The trail was then opened to ORV traffic on April 1, 2004. The largest suspended sediment load contributed by the stream crossing during this study occurred during the trail closed condition. This storm event had a recorded rainfall of 49 mm, and contributed a suspended sediment load of 109 kg. Since there were no storm events sampled with return intervals of more than one year, the WEPP model was used to estimate the potential long term effects of ORV trail stream crossing. A thirty-year synthetic weather data (generated by CLIGEN) was used to predict sediment yield from the ORV trail stream crossing. The WEPP model suggested that average annual sediment load from the stream crossing is about 126.8 tons/ha, which is much higher than what is allowed by the USDA Forest Service-National Forests in Alabama for temporary roads. The model also suggested that most of the sediment load to the stream is contributed by a steep hillslope section that flows directly to the stream. Hence the modeling study suggests that a BMP needs to be implemented to control sediment loss from ORV trail section that contributes sediment directly to the stream. In addition, the ORV trail stream crossing should be located on as flat a slope as possible.
Chin, A., D.M. Rohrer, D.A. Marion, and J.A. Clingenpeel. 2004. Effects of all terrain vehicles on stream dynamics. Pages:292-296 in Guldin, J.M. technical compiler, Ouachita and Ozark Mountains Symposium: ecosystem management research. General technical report SRS-74. Ashville, NC: USDA, FS, Southern Research Station.
Abstract: This paper reports preliminary results from research conducted in the Ouachita National Forest to assess the effects of all-terrain vehicle (ATV) trails on stream characteristics. The study focuses on the Wolf Pen Gap Trail that has been in use since 1991. We examine whether that the trail system has caused increased sediment input to and deposition within stream pools. We compared selected pool characteristics in two watersheds with ATV trails (Gap and Board Camp Creeks) to those in two control watersheds (Brushy and Caney Creeks). Analysis indicates that watersheds with ATV trails have pools with higher percentages of sands and fines, lower depths, and lower volumes. More research is needed to confirm that ATV trails in fact cause these impacts, to determine what factors control impact occurrence, and to better quantify impact magnitude.
Sack, D., and S. da Luz, Jr. 2003. Sediment Flux and Compaction Trends on Off-Road Vehicle (ORV) and other Trails in an Appalachian Forest Setting. Physical Geography 24 (6): 536-554.
Abstract: This research investigates the impact of off-road vehicles (ORVs) on sediment dynamics and compaction in the forested hillslope terrain of southeastern Ohio. A dense network of ground-height change, penetrometer resistance, and penetrometer depth measurements was collected from trails and trail-adjacent forest land at four ORV and, for comparison, two non-ORV trail study sites (hiking, horse-riding). Repeat measurements were made at the height of the ORV season, at the end of the ORV season, and near the end of the off-season. Separate statistical comparisons of ground-height change and penetrometer observations for forest versus trail locations, ORV versus non-ORV study sites, and one time period versus another reveal compaction on all trails, significant surface compaction on the ORV trails, and considerable sediment flux on both the trails and the adjacent forest land at the ORV sites. This flux includes sediment transfer during the riding season from the ORV trails to the adjacent forest land by wash and tire throw. Net erosion that occurred on the ORV trails during the studied part of the riding season was quantitatively offset by off-season aggradation, but the system is primarily one of sediment through-put. Considering the entire riding season, erosion rates on the ORV trails may be as high as 0.11 m3/m2/yr.
Welsh, M.J., L.H. MacDonald, and E. Brown, and Z. Libohova. 2006. Erosion and sediment delivery from unpaved roads and off-highway vehicles (OHV). Presented at AGU fall meeting. San Francisco, CA.
Abstract: Unpaved roads are often the dominant source of sediment in forested areas, and they are of particular concern in the Upper South Platte River (USPR) watershed because this is the primary source of drinking water for Denver, has a high-value fishery, and has a high density of roads and off-highway vehicle (OHV) trails. The goal of this project is to quantify sediment production and delivery from unpaved roads and OHV trails, as there are no data on these sources in the USPR watershed. Since summer 2001 we have been measuring rainfall, sediment production, and segment characteristics from up to 20 road segments, and in August 2005 we began making similar measurements on OHV segments. Sediment delivery is being assessed by detailed surveys of selected roads and OHV trails. Summer rainstorms larger than 10 mm typically produce sediment from each road and OHV segment while undisturbed areas generally produce no surface runoff. The mean annual sediment production from unpaved roads has ranged from 0.4 to 6.7 kg m-2 yr-1, and this variation is largely due to differences in the amount and intensity of summer precipitation. In summer 2006 the mean sediment production from OHV trails was 18.4 kg m-2, or more than 5 times the mean value from unpaved roads. A survey of 17.3 km of unpaved roads showed that 14% of the total road length was connected to the stream network; initial surveys on 3 km of OHV trails indicate a similar degree of connectivity. The overall road density in the study area is about 1.1 km km-2, so unpaved roads are contributing about 1.3 Mg km-2 yr-1 of sediment to the stream network. The results suggest that unpaved roads and OHV trails may be the largest chronic sediment source in the Upper South Platte River watershed.
ORV Impacts to Soil
Belnap, J. 2003. The world at your feet: desert biological soil crusts. Frontiers in Ecology and the Environment. 1(5): 181-189.
Abstract: Desert soil surfaces are generally covered with biological soil crusts, composed of a group of organisms dominated by cyanobacteria, lichens, and mosses. Despite their unassuming appearance, these tiny organisms are surprisingly important to many processes in past and present desert ecosystems. Cyanobacteria similar to those seen today have been found as 1.2 billion-year-old terrestrial fossils, and they probably stabilize soils then as they do now. Biological crusts are vital in creating and maintaining fertility in otherwise infertile desert soils. They fix both carbon and nitrogen, much of which is leaked to the surrounding soils. They also capture nutrient-rich dust, and can stimulate plant growth. These organisms are able to tolerate extreme temperatures, drought, and solar radiation, despite having relatively little wet time for metabolic activity. Under most circumstances, they are extremely vulnerable to climate change and disturbances such as off-road vehicles and grazing livestock. Recovery times are generally measured in the decades or centuries.
Belnap, J. 2002. Impacts of off-road vehicles on nitrogen cycles in biological soil crusts: resistance in different U.S. deserts. Journal of Arid Environments. 52(2): 155-165.
Abstract: Biological soil crusts are an important component of desert ecosystems, as they influence soil stability and fertility. This study examined and compared the short-term vehicular impacts on lichen cover and nitrogenase activity (NA) of biological soil crusts. Experimental disturbance was applied to different types of soil in regions throughout the western U.S. (Great Basin, Colorado Plateau, Sonoran, Chihuahuan, and Mojave deserts). Results show that pre-disturbance cover of soil lichens is significantly correlated with the silt content of soils, and negatively correlated with sand and clay. While disturbance appeared to reduce NA at all sites, differences were statistically significant at only 12 of the 26 sites. Cool desert sites showed a greater decline than hot desert sites, which may indicate non-heterocystic cyanobacterial species are more susceptible to disturbance than non-heterocystic species. Sandy soils showed greater reduction of NA as sand content increased, while fine-textured soils showed a greater decline as sand content increased. At all sites, higher NA before the disturbance resulted in less impact to NA post-disturbance. These results may be useful in predicting the impacts of off-road vehicles in different regions and different soils.
Misak, R.F., J.M. Al Awadhi, S.A. Omar, and S.A. Shahid. 2002. Soil degradation in Kabd area, southwestern Kuwait city. Land Degradation & Development. 13(5): 403-415.
Abstract: Adverse environmental impacts of human activities are the main causes of soil degradation in the desert of Kuwait in general, and in Kabd area in particular. In this study, assessment of soil degradation in open and protected sites has been carried out using field measurements and laboratory investigations. The overall status of vegetation is nearly twice as low in vegetation cover in the open sites than in the protected ones due to overgrazing and off-road transport. Compaction of soil due to pressure exerted on the soil by vehicles led to a significant reduction in its porosity, permeability and infiltration capacity. The average infiltration rate of the compacted soils is 51 per cent lower than that of the non-compacted soils. The bulk density of the non-compacted soils is 3.4 per cent lower than that of compacted soil. The average topsoil resistance of compacted soils has increased by 83 per cent in comparison with non-compacted soil. Using the least squares method a relation between infiltration rate (IR) and penetration resistance (PR) of the topsoil for the study areas is found (i.e. IR = -0.148 PR + 1.85 with R super(2) = 25 per cent). Soil strength within the soil profile shows maximum penetration resistance readings at 11.5 cm depth in average in compacted soils, while it shows maximum readings at 34.6 cm depth in average in non-compacted soils. The adverse changes in the chemical properties due to soil compaction is also investigated. A restoration plan is needed in order to reduce land degradation.
ORV Impacts to Vegetation
Groom, J.D., L.B. McKinney, L.C. Ball, and C.S. Winchell. 2007. Quantifying off-highway vehicle impacts on density and survival of a threatened dune-endemic plant. Biological Conservation 135(1):119-34.
Abstract: Off-highway vehicle (OHV) recreation impacts species and ecosystems around the world, and is particularly prevalent in the United States. Our study examines the impact of OHVs on one of several species restricted within the United States to the Algodones Dunes, California. This dune system attracts many OHV enthusiasts annually, and interest in determining the impact of OHVs on Astragalus magdalenae var. peirsonii (Peirson’s milk-vetch) has motivated multiple investigations. Several of these investigations have arrived at seemingly contradictory conclusions. Our study objectives were to quantify the degree by which A. m. var. peirsonii densities differed between high- and low-OHV use areas and determine whether OHV impact was a plausible factor for affecting plant density. Density estimate comparisons indicated 4–5 times fewer plants occupied a study area open to OHVs relative to two nearby study areas legally closed to OHVs. A manipulative mark-resight experiment compared the survival probabilities of control plants to those purposefully struck by OHVs and found that, for plants with canopy diameters of <50 cm, OHV impact reduced survival by 33%. Density estimates from one of the study areas recently closed to OHVs were surprisingly large, which may suggest that periodic closure of occupied habitat during favorably wet years would assist in ensuring A. m. var. peirsonii productivity and thereby persistence. An improved understanding of this phenomenon may indicate a dunes-wide management strategy that would allow OHV activity to coexist with A. m. var. peirsonii.
Gelbard, J.L., and S. Harrison. 2003. Roadless habitats as refuges for native grasslands: interactions with soil, aspect, and grazing. Ecological Applications 13(2): 404-415.
Abstract: The idea that roadless habitats act as refuges for native-plant for native-plant diversity against exotic-plant invasion has seldom been tested. We examined the effect of distance from roads and its interactions with soil type, aspect, and livestock grazing on native – and exotic-plant diversity in a 130 000-ha inland California (USA) foothill grassland landscape. During spring 2000 and 2001, we measured the numbers of and cover by native and exotic plant species in 92 sites stratified by distance from roads (10 m, 100 m, and >1000 m), soil type (nonserpentine), and aspect (cool, warm, and neutral slopes). In nonserpentine grasslands, native cover was greatest in sites >1000 m from roads (23%) and least in sites 10 m from roads (9%), and the percentage of species that were native was significantly greatest in sites >1000 m from roads (44%) and least in those 10 m from roads (32%). In addition, the most distant sites had the largest number of native grass species and the fewest exotic forb species. In serpentine grasslands there was no significant effect of distance on the numbers of and cover by native and exotic species. On both soils, two exotic species (Centaurea solstialis and Aegilops triuncialis) were at there lowest frequencies, while a native bunchgrass, Nassella pulchra, was at its highest frequency, in sites >1000 m from roads. On nonserpentine soils only, the exotics, Convolvulus arvensis and Polypogon monspeliensis, were at there lowest frequency, while a native bunchgrass, Poa secunda, was at its highest frequency in the most distinct sites. Native species were more abundant on slopes than on flat sites, while on nonserpentine, natives were least abundant on warm, south facing slopes.
Roadless areas are significant refuges for native species. However, to protect these habitats from the continued threat of invasion, land managers should consider means of preventing construction of new roads, limiting off-highway vehicle access into grasslands with low road densities, identifying a regime of livestock grazing that favors the persistence of natives over the spread of exotics, and monitoring recreational trails and grazing allotments within roadless areas to detect and eradicate new infestations.
Munger, J.C., B.R. Barnett, S.J. Novak, and A.A. Ames. 2003. Impacts of off-highway motorized vehicle trails on the reptiles and vegetation of the Owyhee Front. Idaho Bureau of Land Management Technical Bulletin 03-3: 1-23.
Abstract: We used drift fences to trap reptiles near to and far from off-road motorized vehicle (OHMV) trails in the Owyhee Front. We also assessed vegetation. We found that at the less intensively used OHMV site (Fossil Butte), 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 (Rabbit Creek), 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. We largely 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.
Brown, A.C., and A. McLachlan. 2002. Sandy shore ecosystems and threats facing them: some predictions for the year 2025. Environmental Conservation. 29(1): 62-77.
From Summary: Many beaches also suffer intermittent or chronic pollution, and direct human interference includes off-road vehicles, mining, trampling, bait collecting, beach cleaning and ecotourism. These interferences typically have a negative impact on the system.”
From Off–road vehicles: A variety of vehicles, connecting with recreation or industry, may invade a sandy shore, causing different types and degrees of negative impact. Some recreation vehicles, such as motor-cycles, 4X4 vehicles and vehicles of ‘beach-buggy’ type, with large, wide tires, driven up and down dunes, often at considerable speed, cause displacement of sand and destroy dune vegetation. This can be extremely damaging in view of the fragile nature of the dune ecosystem. In addition, shore-birds are disturbed and their nests, eggs and young may be destroyed. Both these and more conventional vehicles may be driven along the beach itself. This often causes little impact along the wet foreshore, although this is not true of all beaches. On some New Zealand beaches, vast numbers of sand dollars (Echinodiscus) dominate the foreshore and are crushed by vehicles (S.C. Webb, Personal communication). Higher up the slope, vehicles are liable to crush semi-terrestrial invertebrates, such as isopods, talitrid amphipods and ocypodid crabs on the surface or in their burrows. Wolcott and Wolcott (1984) considered the negative effects of off-road vehicles on populations of the crab Ocypode, while Van der Merwe (1988) reviewed the literature on the impacts of traffic on coastal ecosystems. Van der Merwe and Van der Merwe (1988) investigated the damaging effects of off-road vehicles on the fauna of a beach, including the crushing of Tylos and Brown (2000) identified off-road vehicles as a major cause of the decline in populations of Tylos granulatus on the South African west coast. Hosier et al. (1981) noted that vehicle tracks in the sand presented barriers to the seaward progress of turtle hatchlings.”
ORV Impacts to Wildlife
Grigg, J.L. 2007. Gradients of predation risk affect distribution and migration of a large herbivore. M.S. Thesis. Bozeman, MT: Montana State University.
Abstract: Few studies have placed wildlife behavioral responses to human disturbance and hunting pressure within the larger ecological context of predator-prey theory. Given that large herbivores respond behaviorally to the presence of wolves and other predators, we should expect similar adaptive behavioral responses when large herbivores are presented with risk in the form of human disturbance and hunting pressure. One index of human access, disturbance, and thus potential predation risk to large herbivores from hunters are road and trail networks bisecting large herbivore ranges. I evaluated the effects of human disturbance and predation pressure in the forms of motorized and total combined access networks on elk (Cervus elaphus) summer home range size, timing of fall migration, and movement rates by placing 49 GPS radio-collars on adult female elk on a winter range in the Madison Valley, MT over the course of a two-year study. I found evidence that elk responded to motorized access during the summer by increasing summer home range sizes. Further, regional variation in predation risk from human hunters resulted in elk subjected to the highest levels of hunting pressure initiating fall migration from summer ranges to winter ranges earlier than elk subjected to lower levels or no hunting pressure. These winter ranges are mostly privately-owned ranchlands that provide relative refuge from hunting pressure. All elk in this study summered on public lands, yet most elk summering in heavily hunted regions were unavailable to public-land hunters for large portions of the hunting seasons due to early fall migration patterns. Movement rate models were ambiguous and I was unable to detect differences associated with motorized and total access levels, though movement rates during the hunting seasons were correlated with varying regional predation risk. This research potentially provides valuable knowledge to biologists across the western United States managing large herbivore populations that summer on public lands and winter in privately-owned agricultural valleys, and provides insight into general predator-prey behavioral relationships.
Wisdom, M.J. 2007. Shift in Spatial Distribution of Elk Away from Trails Used by All-Terrain Vehicles. Report 1, May 2007, USDA Forest Service, Pacific Northwest Research Station, La Grande, OR.
Conclusion: Initial results clearly show that elk avoid ATV trails during ATV use, based on the substantial shift in elk distribution away from trails that was documented for 7 of 9 periods of ATV use (compared to paired control periods). In addition, it appears that elk were not only avoiding ATV trails during period of ATV use, but also increased their avoidance during the last year of study during control periods, in contrast to control periods during the first year of study. This trend suggests that repeated exposure to ATVs caused increased avoidance of ATV trails during both periods of ATV use and non-use. Moreover, the avoidance patterns shown here for ATV trails mirrors results of elk avoidance of roads open to motorized traffic.
Preisler, H.K., A.A. Ager, and M. Wisdom. 2006. Statistical methods for analyzing responses of wildlife to human disturbance. Journal of Applied Ecology 43:164-172.
Summary:
1. Off-road recreation is increasing rapidly in many areas of the world, and effects on wildlife can be highly detrimental. Consequently, we have developed methods for studying wildlife responses to off-road recreation with the use of new technologies that allow frequent and accurate monitoring of human–wildlife interactions. To illustrate these methods, we studied the response of Rocky Mountain elk Cervus elaphus L. to all-terrain vehicles (ATVs), one of the most prominent forms of summer recreation in North America. We studied elk because the species is not only of keen economic and social interest across
North America and Europe but also exemplifies species that can be sensitive to human disturbance.
2. The study was part of a controlled landscape experiment where global positioning system (GPS)-equipped recreationists traversed an established 32-km route inside a 1453-ha elk-proof enclosure. Elk locations before and during the human disturbances were monitored using an automated telemetry system. The unique data set and study objectives led to our development of statistical methods for analysing the response of wildlife to human disturbance.
3. We developed a statistical method, referred to as a probabilistic flight response, which accounted for daily circadian rhythms in movement behaviour of elk, and related the probability of flight to distance to the disturbance and a number of environmental covariates. We also present methods for estimating spatially and temporally explicit movement vectors as a way of detecting and visualizing landscape-level movement patterns.
4. Using these methods, we observed that elk appeared to respond at relatively long distances (> 1000 m) to ATVs, and that the estimated probability of flight appeared to be higher when elk were closer to the ATV routes, even when the distance to an ATV was large.
5. Synthesis and applications. Our study quantifies the response of wildlife to human disturbance at a resolution well beyond previous work, and provides methods to improve our understanding of wildlife–human interactions related to management of wildlife and recreation. These methods may be used for any study involving accurate, frequent monitoring of animals and humans with the use of GPS or similar technologies now commonly available.
Wisdom, M. J., H. K. Preisler, N. J. Cimon, and B. K. Johnson. 2004. Effects of Off-Road Recreation on Mule Deer and Elk. Transactions of the North American Wildlife and Natural Resource Conference 69.
http://bluewaternetwork.org/reports/rep_atv_forestservice.pdf [7]
Abstract: Objectives of the study were to (1) document cause-effect relations of ATV, horseback, mountain bike, and hiking activities on deer and elk; (2) measure effects with response variables that index changes in animal or population performance, such as movement rates, flight responses, resource selection, spatial distributions, and use of foraging versus security areas; (3) use these response variables to estimate the energetic and nutritional costs associated with each activity and the resultant effects on deer and elk survival; and (4) interpret results for recreation management. Among the study's preliminary findings: Elk began moving when ATVs were as far away as 2,000 yards but tolerated hikers to within 500, horseback riders within 800 and bicyclists within 1,300 yards. Elk run from ATVs but tend to walk away from hikers unless startled at close range. Mule deer move little when approached by all four types of recreational users but seem to leave foraging areas and move into deeper cover. Elk are far more disturbed by horseback riders than previously believed, and once they detect them are nearly as spooked by bikes as ATVs.
Bury, R.B., and R.A. Luckenbach. 2002. Comparison of Desert Tortoise (Gopherus agassizii) populations in an unused and off-road vehicle area in the Mojave Desert. Chelonian Conservation and Biology 4(2): 457-463.
Abstract: We examined habitat, abundance, and life history features of desert tortoises (Gopherus agassizii) on two nearby 25-ha plots in western Mojave Desert. An unused, natural plot had 1.7 times the number of live plants, 3.9 times the plant cover, 3.9 times the number of desert tortoises, and 4 times the active tortoise burrows than a nearby area used heavily by off-road vehicles (ORVs); these differences between the plots were all statistically significant. Further, the few large-sized tortoises in the ORV plot had less mass than those in an unused area. Although the scope of this study was limited to one paired-plot comparison, current data suggest that the operation of ORVs in the western Mojave Desert results in major reductions in habitat and tortoise numbers, and possibly the body mass of surviving tortoises. Recent activities in the unused area negated our original design for a long-term comparison of tortoises in two relatively large, nearby control vs. treatment plots. Operation of ORV is now a major recreation in southwestern USA and its effect on wildlife merits increased research studies and management attention to better protect the remaining natural resources.
Janis, M.W., and J.D. Clark. 2002. Responses of Florida panthers to recreational deer and hog hunting. Journal of Wildlife Management. 66(3): 839-848.
Abstract: Big Cypress National Preserve constitutes approximately one-third of the range of the endangered Florida panther (Puma concolor coryi). Because recreational hunting is allowed in Big Cypress National Preserve, we examined 8 response variables (activity rates, movement rates, predation success, home-range size, home-range shifts, proximity to off-road vehicle trails, use of areas with concentrated human activity, and habitat selection) to evaluate how Florida panthers respond to human activity associated with deer and hog hunting. Data consisted of panther radiolocations collected since 1981 by the Florida Fish and Wildlife Conservation Commission and the National Park Service, which we augmented with radiolocations and activity monitoring from 1994 to 1998. A split-plot (treatment and control) study design with repeated measures of the variables for each panther taken before, during, and after the hunting season was used. We did not detect responses to hunting for variables most directly related to panther energy intake of expenditure (i.e., activity rates, movement rates, predation success of females; P>0.01). However, panthers reduced their use of Bear Island (P=0.021), an area of concentrated human activity, and were found further from off-road vehicle trails (P<=0.001) during the hunting season, which was indicative of a reaction to human disturbance, Whereas the reaction to human activity on off-road vehicle trails probably has minor biological implications and may be linked to prey behavior, the decreased use of Bear Island is most likely a direct reaction to human activity and resulted in increased use of adjacent private lands. Future habitat loss on those private lands could exacerbate the negative consequences of this response by panthers.
Nicola, NC, and JE Lovich. 2000. Preliminary observations of the behavior of male, flat-tailed horned lizards before and after an off-highway vehicle race in California. California Fish and Game 86(3): 208-212.
“Our small sample of male, flat-tailed horned lizards exhibited reduced rates of movement following disturbance from OHVs. This coupled with the fact that flat-tailed lizards are often sighted on roads (Norris 1949, Turner and Medica 1982), may make them especially susceptible to mortality from vehicle strikes. While driving a vehicle, Wone and Beauchamp (1995) observed that the majority (86% of flat-tailed horned lizards they encountered fled for short distances and stopped, sometimes under shrubs, and sometimes on OHV trails. Thus, flat-tailed horned lizards may attempt to avoid OHVs, although road mortalities have been observed when lizards fail to move out of the way of oncoming traffic (Muth and Fisher 1992)”
“The consequences of moving at different rates and directions after a disturbance may be negative or positive. If these changes fail to take the animal away from the area of impact, or the movements are energetically costly, the consequences may be negative. If the movements decrease the probability of an animal being struck by an OHV, then the consequences are potentially positive. While our analysis is preliminary because of a small sample size, the data are the first to suggest that OHV activity affects movement of the flat-tailed lizards.”
Vieira, M.E.P. 2000. Effects of Early Season Hunter Density and Human Disturbance on Elk Movement in the White River Area, Colorado. Unpublished M.S. Thesis. Fort Collins, CO: Colorado State University.
From Abstract: “I also conducted a series of pedestrian and all-terrain (ATV) disturbance trials on radio-collared elk as a first step in assessing the extent to which hunters on ATVs, relative to pedestrian hunters, may be causing increased elk movement. Radio-collared elk on accessible public land were treated with a randomly assigned treatment of either a single pedestrian or single ATV disturbance. The gross distance moved in the 24 hours following the disturbance was calculated using before-treatment and after-tretment telemetry locations. The same group of elk was also used in the single disturbance trials were randomly selected and treated with 3 successive daily pedestrian disturbances. Instances moved in the 24 hours following each disturbance were measured. An ANOVA comparing the distance moved between the single pedestrian (¬mean=850 m, SE=190, n=9) and single ATV (mean=1910m, SE=480, n=8) disturbed groups showed a distinct treatment effect (P=0.048), with the ATV movement mean being more than twice the pedestrian mean….”
Stensvold, M.C. 2000. The conservation status of Ophioglossaceae in southern Alaska. Proceedings of Botany 2000. August 6-10. Portland OR.
Abstract: In southern Alaska the Ophioglossaceae are represented by one species of Ophioglossum and eight named species of Botrychium. In the latter there are six species of moonwort ferns (subgenus Botrychium), one grapefern (subgenus Sceptridium), and B. virginianum, the rattlesnake fern in subgenus Osmundopteris. In addition, there are three distinct undescribed species and several unusual moonworts not clearly fitting known taxa. The State of Alaska does not maintain a threatened and endangered species list, but the U.S. Forest Service is mandated to manage habitats to maintain viable populations of plants; therefore Botrychium is afforded protection on National Forest System lands. Habitat disruption resulting from off-road vehicle use and trampling are currently the greatest human-caused threat to Botrychium. Several Botrychium occupy sandy beach-beach meadow habitat, and this habitat is used by an increasing number of off-road vehicles, resulting in Botrychium habitat degradation. Only after the taxonomy, distribution and habitat needs of Botrychium are better understood, and the various landowners cooperate in land use management, will we be able to effectively deal with Botrychium conservation issues across southern Alaska.
Other ORV Impacts
Sampson, M.P. 2007. The Effects of Off-Highway Vehicles on Archaeological Sites and
Selected Natural Resources of Red Rock Canyon State Park. California State Parks. Published online at: http://www.parks.ca.gov/?page_id=24576 [8]
Abstract: An investigation of off-highway vehicle effects with a focus upon archaeological sites and historical properties within Red Rock Canyon State Park was conducted in 2004-2006. Thirty-six archaeological sites, as well as, sensitive plant and animal habitat and geologic features, are known to be traversed by roads and informal vehicle trails. Damage related to vehicle use consists of the following: long-lasting vehicle scars upon the land, loss of soils and vegetation, gullying, deflation of cultural deposits, displacement and damage to artifacts and geologic features, and others. Soil deflation along roads and the volume of soil loss were found to be significant at certain locations. Solutions to the vehicle-caused problems include the following: installation of effective vehicle barriers, closure of certain routes or route segments, public education, increased patrol by park rangers, regular maintenance of routes of travel, application of erosion-control measures, restoration of damaged terrain, regular monitoring, and others.
Celliers, L, T. Moffett, N.C. James, and B.Q. Mann. 2004. A strategic assessment of recreational use areas for off-road vehicles in the coastal zone of KwaZulu-Natal, South Africa. Ocean and Coastal Management 47(3-4): 123-140.
Abstract: In January 2002, the Minister of the Department of Environmental Affairs and Tourism of the South African government promulgated new regulations controlling the use of off-road vehicles in the coastal zone of South Africa. The new regulations provided for a general prohibition on the recreational use of off-road vehicles (ORVs) in the coastal zone as well as providing procedure for approving the use of vehicles in the coastal zone under specific circumstances. The regulations now specify that recreational use of ORVs can only take place in designated recreational use areas (RUAs). This paper described the process of developing a cohesive strategy for the siting of RUAs in the coastal zone of KwaZulu-Natal. This strategy was developed to avoid ad hoc application for areas that might be unsuitable (environmentally or socially) for ORV use. Potential RUAs was identified using seven principles that disqualified areas not suitable, and subjecting the potential RUAs to a number of other considerations. The seven principles are sufficiently generic to be applied to the other three coastal provinces of South Africa and probably further afield. This strategy identified a network of ecologically and socially justifiable RUAs along the coast of KwaZulu-Natal. These areas will not be designated automatically but each area will need to be further scrutinized by an environmental impact assessment.
Durbin, T.D., M.R. Smith, R.D. Wilson, S. H. Rhee. 2004. In-use activity measurements for off-road motorcycles and all-terrain vehicles. Transportation Research Part d Transport and Environment 9(3): 209-219.
From Introduction:
“As emissions for individual on-highway vehicles continue to decrease, it is becoming increasingly important to understand the emissions from off-road mobile sources. Off-road recreation vehicles (also known as off-highway vehicles, or OHVs) are one important source of emissions that make a disproportionately high contribution to the emissions inventory. The category includes off-road motorcycles and all-terrain vehicles (ATVs)”
“Hydrocarbon (HC) emissions from 2-stroke engine equipped motorcycles are about 10 times greater than those from a comparable 4-stroke motorcycle on a per mile basis. For the OHV class, 2-stroke engines represent about 90% of the smog precursor emissions in California (California Air Resources Board, 2001). The HC emissions for both 2-stroke and 4-stroke motorcycles are also significantly higher than those from a typical new car. Nationally, recreational vehicles (including snowmobiles) represent approximately 10% of all mobile source HC emissions and 3% of all mobile source CO emissions (US Environmental Protection Agency, 2001). In California, emissions from recreational OHVs (including off-road motorcycles and ATVs) represent 2.8% of the reactive organic gas (ROG) emissions and 1.4% of the CO emissions from all mobile sources (California Air Resources Board, 2000).”
Priskin, J. 2003. Physical impacts of four-wheel drive related tourism and recreation in a semi-arid, natural coastal environment. Ocean & Coastal Management 46(1-2): 127-55.
Abstract: The aim of the research was to assess the physical impacts of four-wheel drive related nature-based tourism in the Central Coast Region of Western Australia. This coast is 271 km long, in a natural and largely undeveloped state, but coastal recreation impacts due to four-wheel drive use has increased significantly since the 1960s. Research methods included interpretation of aerial photographs for 1965 and 1998 for a 1 km zone, measured immediately landward from the shoreline. Features associated with recreation use, such as off-road tracks and access points to beaches were digitized and analyzed using Geographic Information System. For 1965, 516.5 km of four-wheel drive tracks were measured, compared to 812.9 km in 1998. Access points to the coast also increased from 421 to 908 during the same period. Results were analyzed within 25 biophysical and five local authority units. Results within biophysical units were related to physiographic setting, beach and dune type.
Baxter, G. 2002. All terrain vehicles as a cause of fire ignition in Alberta forests. Advantage (Publication of the Forest Engineering Research Institute of Canada). 3(44): 1-7. http://fire.feric.ca/other/AD-3-44.PDF [9]
Abstract: This study was initiated upon the request of Alberta Environmental Protection to investigate the relationship between all terrain vehicle (ATVs) and fire ignition within Alberta’s forests. The report summarizes the use of ATVs in Alberta and the specific
causes of wildfires associated with these vehicles, describes fire history from 1990 to
2002, reports on other agencies’ strategies to lower the probability of ATV-caused fires in forested areas, and makes recommendations for Alberta.
Bureau of Land Management. 2000. Strategic paper on cultural resources at risk. Bureau of Land Management, Washington, D.C. 18p. http://www.blm.gov/heritage/docum/00atriskpaper3.pdf [10]
From External threats:
“Uncontrolled use is the most immediate and pervasive threat to cultural resources on BLM lands. But one of the most enjoyable aspects of visiting BLM lands, compared to other federal lands, is the freedom experienced by visitors because of the lack of restrictions that are placed on them. The public lands are fast becoming more accessible, better known, and more intensively used. In many areas, urban sprawl, encroaching on previously remote areas, is turning the public lands into recreational backyards. The explosion in the use of mountain bikes and ATVs, and even the designation of backcountry byways, has dramatically increased visitation to lands that were previously used only by small numbers of hikers. This increased visitation inevitably results in intentional and inadvertent damage through collection, vandalism, surface disturbance, and other depreciative behavior.”