Trails are a form of recreational disturbance affecting natural areas. Trail disturbances can cause soil degradation such as compaction, which facilitates soil erosion and overland water flow. This study analyzed the effects of four different types of trails—paved, gravel, equestrian, and hiking—on soils in the Oak Openings of Northwest Ohio, a globally rare ecosystem that harbors more than a third of Ohio's rare plant species. Bulk density and soil moisture content were measured in order to determine physical impacts of trails. Soil pH, ammonium, nitrate, phosphate, and dissolved organic C and N concentrations were measured to determine effects on soil chemistry. Finally, soil microbial biomass and exoenzyme activities were measured to determine biological responses to trail disturbances. Soils from the gravel trail were the most affected by the trail, with significant effects on chemical (PO43-concentration) and biological (phosphatase and NAG activity, and MB-N) properties. The soils near the paved trail were the second most affected after the gravel trail, with a trend toward a pH change and a significant biological (microbial peptidase activity) effect of this trail. The soils of the horse and natural trails were generally not significantly different from the soils in the surrounding ecosystem. The only significant disturbance in the horse trail was increased bulk density in the trail, while the natural hiking trail had no statistically significant differences, but trends lean toward increased bulk density and reduced microbial phosphatase activity. These results suggest that the natural and horse trails have the least impact on the Oak Openings ecosystem.

Jared Hawkins and Michael N. Weintraub. 2011. “The Effect of Trails on Soil in the Oak Openings of Northwest Ohio.” Natural Areas Journal 31(4):391-399.