OOS 31-9
Uncovering the role of soil and plants in urban ecohydrology

Tuesday, August 11, 2015: 4:20 PM
336, Baltimore Convention Center
Marie R. Johnston, Soil Science, University of Wisconsin - Madison, Madison, WI
Nick J. Balster, Soil Science, University of Wisconsisn - Madison, Madison, WI

The urban environment offers a unique opportunity to study how ecological practices might mitigate the effects of urbanization on soil structure and function, yet these practices remain largely untested with regard to their most fundamental controls: plants and soil. Here, the interactions between plants and soil are investigated as a means for improving the physical properties and hydrologic function of urban soil. This presentation will combine results from controlled field experiments, greenhouse studies, and surveys of mitigation practices on residential property to discuss the quantitative potential of plant-soil interactions. I will also discuss a method for helping to distinguish between plant traits to aid landowners in the design of these ecologically engineered tools.


Results suggest plant-soil interactions are critical for the short and long-term function of vegetated best management practices promoted for urban stormwater management. Differences in the timing and magnitude of soil drainage from closed-system mesocosms provided quantitative evidence supporting the importance of plants in altering soil hydrology through changes to soil porosity and soil moisture. Prairie vegetation best exemplified such changes, with three-fold faster drainage flow rates, eight-fold greater infiltration, and improved soil pore diameter and connectivity compared to non-vegetated controls. Differences in biomass accumulation and allocation among prairie species further supported the utility and consideration of these plantings for urban environments. Overall, this research shows that vegetation offers an ecological alternative (as opposed to mechanical engineering) that might be embraced by private landowners to help manage soil and water resources in urban landscapes.