It is increasingly common for the Forest Service, timber industry and even some conservation groups to assert to the public that temporary roads used to access logging/thinning projects on national forest lands are ecologically neutral.
Temporary roads, however, are nearly as destructive and in some cases even more damaging to wildlife and wildlands than a permanent road.
The impacts of roads are not hidden science. As early as the 1970s, Dr. Jack Lyons published an article in the Journal of Forestry that examined the cumulative effects of road density and how elk use the spaces between them. What he found is evident today – elk avoid roads.
Numerous other studies have only reinforced these findings. For instance, one study in the Journal of Wildlife Management, which used radio-collared elk to determine the relationship between roads and elk distribution concluded: “Our study, combined with several previous studies, suggests that substantial shifts in elk distribution away from open roads are a widespread phenomenon.”
Another study published just this year looking at the impact of roads, and motorized use on grizzly bears in Alberta concluded: “We found that motorized access affected grizzly bears at the individual and population levels through effects on bears’ habitat use, home range selection, movements, population fragmentation, survival, and reproductive rates that ultimately were reflected in population density, trend, and conservation status.”
The idea that an elk or bear displaced by a temporary road can go someplace else assumes there is someplace else to go. If the habitat is suitable for any species, it will already be occupied. In effect, roads reduce habitat quality and quantity for affected species.
Even when a temporary road is closed and “restored,” most remain effectively a transportation corridor that allows people to mountain bike, drive ATVs or even walk into areas that otherwise would provide refuge and habitat security to wildlife. Most “closures” involve no more than a gate or sometimes just a sign announcing that the road is closed. And numerous studies have demonstrated that such tactics are regularly ignored and violated.
The impacts go well beyond the effect on habitat security for elk and grizzlies. I have seldom seen restored roads that were fully converted back to the original condition. In most cases, the road lens is not restored, and the road cut allows subsurface water to collect on the road pathway, often contributing to increased erosion. The steep side slope of a road cut is one of the reasons why roads are a chronic source of sedimentation in streams, negatively impacting aquatic ecosystems.
Besides, stream crossings usually require culverts – which often block the upstream movement of fish and other aquatic animals and are prone to wash out by storms.
Road surfaces become compacted soil that can last for decades, and thus shed water instead of allowing it to soak in, again contributing to more gullying and erosion.
Roads are one of the main vectors for the spread of weeds and flammable grasses like cheatgrass that thrive on disturbance.
Roads are also associated with higher human ignitions. Again, even closed roads provide access to areas that might otherwise not see human use.
Then there is the issue of how roads affect fire spread. Several studies show that the area exposed by the roadbed heats up faster than shaded forests, thereby providing a suitable pathway for fire spread. The roadbed also facilitates the flow of warm air into forested stands, again creating conditions more favorable to fires.
Since “temporary” roads are not expected to be used as long as a “permanent” road, they are built to lower standards, thus more susceptible to blowouts and other erosion during storms and floods.
Anyone who asserts that thinning or logging is OK because there are “only” temporary roads is demonstrating overall ignorance of road ecology and their ecological impacts.
George Wuerthner is a former Forest Service employee in Idaho and an ecologist who has published 38 books including “Wildfire: A Century of Failed Forest Policy.”