The Impact of Overlanding
How off-road vehicles impact the environment
What is overlanding?
Overlanding describes a method of off-road camping and travel, that has been increasing in popularity in recent years (1). Typically, the mode of transportation is by off-road vehicles such as bicycles, motorbikes, and cars (the more common ones being 4-wheel trucks, crossovers, and SUVs) to travel through or remote locations that aren’t as easily accessible or explored by the general public (1). Off-road vehicles rigged with camping and outdoor utilities are seen throughout social media as an enticing way to get more people to explore the outdoors. The main goal is to travel through unknown terrain all the while being self-sufficient, which requires adequately equipped vehicles to ensure that the ORV can tough it out through harsher terrains.
(Image/Summit Racing – Smittybilt)
Does overlanding negatively impact the environment?
Various impacts due to off-road vehicles and overlanding can degrade natural spaces. Of course, it is commonly known that humans heavily impact natural spaces by leaving waste and disturbing untouched areas. Off-road vehicles (ORVs) have the capability of affecting a natural space on multiple scales. With the increasing trend in overlanding in recent years, there are amplified disturbance levels throughout a single area and can result in permanent or long-term damage. ORVs can impact the soil, watersheds, vegetation, wildlife, natural habitats, water, air quality, etc. (2).
Nature-based tourism and recreation in public spaces and protected areas are increasing internationally (2). Some human-based impacts can cause such a significant amount of damage. It alters the area’s value for tourism and recreational opportunities if kept unchecked, and visitors are not responsible campers, hikers, etc. (2). With the recent rise in visitors’ numbers to national parks and forests, especially within the last year due to COVID-19, activities such as overlanding can increase negative environmental impact and even affect the overall quality of experience in the area. Irresponsible visitors to such parks may lead to the degradation of protected areas (which is considered vandalism). One incident occurred in 2016 regarding the Racetrack Playa in Death Valley, where an individual in an off-road vehicle had torn up the crust of the lake bed simply because the individual in question decided to have a joyride and damage over 10 miles of protected lands.
(Park Service photo via Facebook)
Recreational activities within protected areas are, for the most part, restricted, except for activities that are considered less damaging to the environment (such as hiking) (2). The most common or obvious impact on protected areas is vegetation damage. Still, activities such as overlanding can heavily impact the soil, including erosion, sedimentation, nutrient loss, pollutant runoffs, etc. (2) Not only this, but many ORV owners may not consider the impact their tires may have as vectors for nonnative and invasive plants to enter a sensitive environment, but the traction may also uproot and crush vegetation as well (2).
In short, increased overlanding and other recreational activity result in increased damage to the environment.
ORV Impact on Soils and Watersheds
Heavy overlanding activity and traffic can result in long-term effects that degrade soil and watershed functions by altering the soil structure (3). Soil compaction is the primary concern, along with destroying the soil’s crusts and shifting finer gravel surfaces (desert pavements) (3). All of these components help stabilize the soil and prevent soil erosion (3). As soil compaction due to tire pressure and vehicle weight, the soil’s capability to support diverse vegetation decreases due to the soil’s overall strength and complex structure declining - meaning the soil is less porous for water and nutrient absorption (3). This can lead to reductions in vegetative cover and preventing the growth of stable root systems since soil stability is disrupted and, depending on the amount of precipitation within an area, can lead to soil runoff rates increasing which only accelerates the effects of soil erosion (3).
ORV Impact on Vegetation
Plants are commonly associated with ORVs and overlanding in terms of damage. The compaction of soil deters the plant’s overall growth by limiting the amount of moisture available on the surface, which in turn prevents the taproot (a type of root system that grows vertically rather than horizontally) from penetrating deeper into the soil and increases the chances of the plant dying (3). This dramatically impacts native plants depending on the region in terms of size and abundance throughout the area, potentially leading to nonnative plant species invading the space (3). If ORV’s are taken further off the designated roadways, this can also result in the top portions of native plants breaking or being crushed and likely lead to reduced photosynthetic activity, limited reproductive success, and lessens the amount of ground cover and plant debris for forest floors (3). Not only does the plant being physically damaged decrease photosynthetic activity, but the dust that is raised by tires or heavy amounts of traffic in the area can disrupt the cycle, which can also suppress plant growth (3). Endemic (native) plant species impacted by ORVs can lead to reduced plant distribution and lead to early successional species such as shallow-rooted grasses invading and dominating the entire landscape if given a chance, affecting all aspects of biodiversity within the area.
ORV Impact on Wildlife and Habitats
Habitats and native species (and threatened and endangered) can be impacted by ORVs in multiple ways, with habitat degradation being the main focus. Habitat fragmentation or limits in habitat connectivity since roads and trails used for overlanding increase throughout an entire ecosystem (3). Habitat fragmentation leads to plant and animal movement or dispersal is limited, affecting population size and distribution (3). Noise due to decibel levels and noise durations that are larger than the typical amount of background noise can affect wildlife (3). Excessive amounts of noise and disturbance lead to impacts ranging from physiological and behavioral stressors. Stress and mortality are the leading causes of wildlife impacts from ORV activity (3). In terms of mortality, when ORVs drive across native landscapes, it can lead to damage of native vegetation used for nesting, collapsed underground burrows, inner ear bleeding, and vehicle-animal collisions, to name a few (3). ORV noise affects wildlife behaviorally-speaking by disrupting natural dispersal patterns that lead to declines in overall population sizes and activity levels of various species as well (3)
ORV Impact on Water Quality
Overall water quality can decrease if overlanding activity levels are incredibly high. ORVs in natural spaces can impact natural waterways, including sedimentation, turbidity, and pollution (3). Because of the potential for soil to become compacted by ORV tires, this increases the likelihood of sedimentation occurring within waterways and increases the amount and rate of runoff, thereby accelerating the amount of debris and soil eroded into natural aquatic systems downstream (3). Pollutants commonly associated with ORVs are primarily gasoline and oil, and other products that may accidentally be released into the water and absorbed into the soil and plants (3).
ORV Impact on Air Quality
When ORV traffic causes dust to rise up from the trail, it emits by-products from the car’s exhaust (3). Since wind can disperse and suspend these particulates for long distances, this can lead to plants being covered with dust and prevent proper function and spread out contaminants further out to areas that may not be near or accessible ORVs (3). Some of these contaminants that ORVs release include polycyclic aromatic hydrocarbons, sulfur dioxide (SO2), nitrogen oxides (NOx) and ozone (O3), etc. (3). Leaded gasoline is not common in the U.S. since the late 1990s. Still, lead emissions deposited into areas before the ban on leaded petrol may remain in the area for decades and continue to degrade the ecosystem, along with the addition of fresh oil leaks and gasoline spills leading to downwind contamination of water, air, and soil quality (3).
References:
“What Is Overlanding.” Overland Journal, overlandjournal.com/what-is-overlanding/.
Pickering, Catherine Marina, and Wendy Hill. “Impacts of Recreation and Tourism on Plant Biodiversity and Vegetation in Protected Areas in Australia.” Journal of Environmental Management, vol. 85, no. 4, 2007, pp. 791–800., doi:10.1016/j.jenvman.2006.11.021.
Ouren, Douglas S., et al. “Environmental Effects of off-Highway Vehicles on Bureau of Land Management Lands: A Literature Synthesis, Annotated Bibliographies, Extensive Bibliographies, and Internet Resources.” Open-File Report - USGS, 2007, doi:10.3133/ofr20071353.