Residential Prairie Gardens As a Tool for Soil and Water Conservation in Urban Environments.

Soil and water conservation practices in the urban environment often promote native vegetation to mitigate the effect of urbanization on local hydrology and soil processes, yet these practices remain largely untested with regard to the dynamic interaction between plants and soil. Using the results from empirical studies of residential yards and controlled field experiments of replicated bioretention cells, I will discuss the role of prairie vegetation as an ecological engineering alternative to help manage soil and water resources in the urban landscape. I will first report on the use of prairie gardens installed by landowners on residential properties in Madison, WI, as a tool to improve the physical properties and hydrologic function of urban soil. In a second study, a controlled field experiment of 12 closed-system mesocosms of four vegetative treatments provided quantitative evidence that plants alter soil hydrology through changes to soil porosity and soil moisture. Results from these studies suggest that plant-soil interactions are critical in determining the short and long-term function of vegetated best management practices promoted for urban stormwater management. A method for grouping prairie species according to crown morphology and flowering phenology to aid landowners in the design of urban plantings will also be presented.