Spatial Extent of the Impact of Transported Road Materials on the Ecological Function of Forested Landscapes

Principal Investigator: Dr. Deborah Neher (Plant & Soil Science Department)
Funding Agency: US DOT

Project Summary

We are investigating the impact of different types of roads on the plant community structure and soil environment (chemical and biological) of nearby forests. Our hypothesis is that de-icing salt and other road particles alter the soil environment and local plant diversity of surrounding forests, and that the extent of the impact decreases with greater distance from the road. Furthermore, this impact is likely to vary depending on road type and presence or absence of a swale to collect and redirect material flows. We are sampling plant community structure, soil chemistry, and soil biology of the roadside landscape for three road types (unpaved, paved 2-land, and highway) and two road profiles (swale, no swale) at six different distances from the road edge. We will also include additional variables such as traffic volume in the analysis. The sampling location, road edges, and all sampling points are precisely geo-referenced and mapped. At each sampling location, measurements of slope, aspect, elevation, road width, tree canopy gap width will be determined. This empirical data will be used to develop a methodology that can be used within transportation models to determine the total landscape impact based on alternative development scenarios and road density patterns.

Project Overview (PDF, March 2010)