Laura Taylor Johnson

Project Title: ”The effect of two-stage ditch construction on stream ecosystem function“

External Partnership: Indiana Chapter of The Nature Conservancy
Internal Partnership: Jake Bealieau

In the Midwest, agricultural land use has altered stream ecosystem function by increasing nitrogen concentrations (N) via fertilizer use and changing stream channels to increase water flow to downstream ecosystems.  The combination of increased anthropogenic N and faster water velocity leads to saturated stream nutrient demand resulting in degraded downstream habitat.  This nutrient saturation has even been linked to eutrophication and seasonal hypoxia in the Gulf of Mexico.  Recently, two-stage ditch construction has emerged as a possible solution to this problem.  The two-stage ditch is unique because it retains the function of a ditch while leading to better water quality, stabilized banks, and self-sustained sediment removal ending ditch excavation.  Although these results had been found in previous research, the influence of two-stage ditches on stream ecosystem functions had been overlooked until Laura and Jake's research.  Stream ecosystem functions, such as primary production, are typically more sensitive to ecosystem change therefore are potentially a better indicator of the influence of restoration activities in comparison to estimates of biomass or water chemistry.  In this project, Laura and Jake investigated the influence of two-stage ditch construction on stream ecosystem metabolism.

Distinctive Outcomes: Since her CAC fellowship, Laura has moved on to a postdoctoral fellowship at Indiana University. She has also worked with others to rework USDA guidelines.