Transportation and Ecology

How do roads affect the surrounding landscape? How do those effects vary by road type and distance from the road? Those are some of the questions Kristin Williams, a M.S. student in Plant and Soil Science has been addressing in her thesis:  “Spatial effects of roads on soil nematode communities in forested areas of Vermont.”

Under the support of Deborah Neher and Sarah Lovell, Kristin addressed these questions by taking soil samples in transects perpendicular to gravel, 2-lane paved and highway roads. Soils were analyzed for both soil chemistry properties, such as salt and heavy metals, and biological properties. Soil nematodes are microscopic roundworms that occupy a diverse array of positions on the soil food web.  For example, different nematodes consume bacteria, fungi, plant roots, and other soil fauna including other nematodes. This makes them great indicators of the entire soil food web. Additionally, they are also known to have differential responses to disturbance, including that of salts and heavy metals.

Results suggest that the roadside environment does alter the soil community. This is probably due to a combination of pollution, water regime, altered soil (e.g., compaction), and altered plant communities.  Kristin’s research is linked to another M.S. student, David Asmussen, who examined roadside plant communities.  Results from both projects suggest that the forest edge acts as a filter for pollution and habitat degradation, and that roadside design may be improved by conscious design of forest edge structure, function and location.

Together these two projects are a segment of UVM Transportation Research Center Signature Project 1, “Integrated Land-use, Transportation and Environmental Modeling: Complex Systems Approaches and Advanced Policy Applications” Funded by the Federal Department of Transportation, led by Austin Troy, this innovative transportation project was developed with the aim of being a national showcase for the testing and validation of integrated models and for more sustainable transportation planning.

Transportation and Sociology

Kristin is wrapping up her thesis and will graduate this fall.  The skill sets and interests she developed in her graduate studies have led her toward a new, but related, opportunity.  She was recently hired as a research assistant for a different project funded by the TRC.  Under Tomas Macias and Richard Watts, Kristin is researching how social capital, specifically what sociologists call ‘weak ties’, influences environmental concern and transportation behavior. ‘Weak ties’ are essentially a person’s extended social network. The hypothesis being that a person with a more diverse array of weak ties has both more resources and more exposure to different paradigms or viewpoints, including those of ecological relevance. This may then lead to more environmentally conscious transportation decisions, specifically reducing tailpipe emissions.

While Kristin’s thesis involves developing ecological knowledge that can lead to better human design decisions, her work with sociology is looking at how social networks influence human decision making that affects the environment. Of her experiences, she says “Working with the TRC has not only funded my education, it has given me an incredibly rich array of opportunities and perspectives on transportation that I would not otherwise have.  The TRC is truly a model for interdisciplinary education and I am very grateful for all the support they have given me. It is this kind of thinking, linking ecology and decision making in both directions, which I believe will help move society forward towards more sustainable transportation networks.”