Riding ATV’s and motorcycles around the forest can be incredibly fun and exhilarating. But in order to make sure those trails stay open, it’s vitally important to limit erosion in the areas you enjoy. Going off trail risks your safety, as well as the safety of the plant life and soil itself.
And though it might not seem related, did you know that just over half of the nation’s water supply originates in forestland?1 Snowfall melts, and rain sinks through the soil. That precipitation in forests is what eventually supplies our cities and private wells.2 Water for our homes and businesses, including agriculture, relies on healthy forest soils.
As our major source of water, forests in the United States National Forest System account for only 11% of our land. So in order for us to have clean and safe drinking water, our forests must have healthy and undisturbed soil.
Designing trails for hikers, bikers, and motorized vehicles is a rigorous process. Recreational planners map the areas least likely for soil erosion. They also map out the safest paths for foot and vehicle traffic. They need to keep us out of streams. Each step a hiker takes off the trail can harm the soil and forest ecosystem.3 The weight of you, plus your off-road vehicle, can be up to 400-500 pounds! Motorcycles and ATVs can cause more damage off trail than humans can.
The tires of the ATV or motorcycles cause soil compaction when they make tracks. Compaction decreases soils’ ability to capture and hold water. Land managers try to keep the amount of soil compaction to a minimum in the forests by creating the path system. Off-trail use compacts the soil. The weight can easily generate deep ruts with even one pass.
These tracks can quickly channel water down the hills, and lead to increased erosion into the streams below. On steep slopes (of 30% or more), this is a larger concern because as water picks up speed it can carry more sediment and deliver it to streams, hurting fish populations.4 If enough riders continue making their own trails, the area can become unsightly and eventually be more susceptible to landslides.
Soil compaction harms the trees in the forest, too. Since compacted soils hold less water than uncompacted soils, the trees can struggle to get the water they need – especially in the hot summer months.
Well-built trails have water bars (also acting as mini-jumps) that help to direct water away from bare soil and decrease erosion. They also minimize the number of times you cross a river or stream. This limits the impacts on water resources that are key to healthy ecosystems.5
When you stay on the trails in our park system, you minimize soil compaction and erosion. This keeps our forests healthy, our water clean, and the fish, trees, and your family happy!
Answered by Adrian Gallo, Oregon State University.
- Brown, T., M. Hobbins, and J. Ramirez. 2005. The Source of Water Supply in the United States – RMRS-RWU-4851 Discussion Paper. Rocky Mountain Research Station. USDA Forest Service. Fort Collins, CO.
- To read more about how snowmelt becomes drinking water, read this Soils Matter blog: https://soilsmatter.wordpress.com/2017/03/01/1184/
- To learn more about why it’s important to stay on foot paths in parks, read this Soils Matter blog: https://soilsmatter.wordpress.com/2015/06/15/why-does-it-matter-if-i-stay-on-the-trail-while-hiking-in-the-woods-and-parks/
- Suttle, K., M. Power, J. Levine, and C. McNeely. 2004. How fine sediment in riverbeds impairs growth and survival of juvenile of salmonids. Ecological Applications. 14(4): 969-974
- Welsch, David. 1991. Riparian forest buffers. Function and design for protection and enhancement of water resources. Forest Resources Management NA-PR-07-91. USDA Forest Service. Radnor, PA