Nitrogen Leaching in Riparian Autumn-Olive Stands in Southern IllinoisEPA Grant Number: F5E61407
Title: Nitrogen Leaching in Riparian Autumn-Olive Stands in Southern Illinois
Investigators: Goldstein, Christine L.
Institution: Southern Illinois University - Carbondale
EPA Project Officer: Zambrana, Jose
Project Period: September 1, 2005 through August 1, 2007
Project Amount: $74,000
RFA: GRO Fellowships for Graduate Environmental Study (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
Autumn-olive is a nitrogen fixing, invasive woody shrub that has become established in many pastures and old fields in the eastern United States.
To determine whether excess nitrogen (nitrate and ammonium) is leaching below riparian autumn-olive stands, potentially contributing to stream nitrogen loads.
To achieve this objective, we installed six tension lysimeters in both autumn-olive and open field plots at three riparian sites in southern Illinois. Soil water samples were collected monthly and analyzed for dissolved nitrate, ammonium, pH, and specific conductivity. When graduate research commences in fall 2005, the soil water samples will be collected every two weeks. We will also be installing groundwater wells to determine if nitrate in soil water is leaching into the water table. We also plan to sample stream water from local headwater watersheds with varying percent coverage of autumn-olive to determine if there is a relationship between autumn-olive and stream nitrogen concentrations at the watershed scale.
To date, soil water ammonium concentrations have been relatively low and were similar between autumn-olive and open field plots. Soil water nitrate concentrations were relatively high under autumn-olive stands and were significantly higher than open field plots. We expect similar results with future soil water and groundwater samples. We also expect to find higher nitrate levels in the streams with the higher percent autumn-olive cover.