You are here:
Using soil isotopes as an indicator of denitrification in weetlands
Citation:
NAHLIK, A. M., M. E. KENTULA, W. J. Mitsch, M. Hernandez, AND K. Song. Using soil isotopes as an indicator of denitrification in weetlands. Presented at 2012 EcoSummit International Conference, Columbus, OH, September 30 - October 05, 2012.
Impact/Purpose:
Denitrification is an important ecosystem service provided by wetlands, which results in removal of excess nitrogen that can threaten aquatic systems.
Description:
Denitrification is an important ecosystem service provided by wetlands, which results in removal of excess nitrogen that can threaten aquatic systems. Unfortunately, direct measurement of denitrification has traditionally been expensive, time intensive, and difficult. However, there is evidence that the soil nitrogen isotopes associated with soil organic matter reflect the quantity of denitrification that has occurred in a wetland. If the relationship between soil isotope signatures and actual denitrification can be determined, soil isotope analyses, which are comparatively inexpensive, rapid, and easy, can be used to estimate quantities of denitrification. Pilot studies to develop a soil isotope indicator of denitrification are currently being conducted using archived soils from three different hydrologic settings in two created wetlands located at The Ohio State University’s Wilma H. Schiermeier Olentangy River Wetland Research Park. Preliminary results show that the δ15N associated with soil organic matter from soils collected in 2004 and 2009 are weakly, but significantly correlated to in-situ denitrification measurements collected in the same areas during the same time periods. We will present details of this analysis and illustrate the potential for this indicator to estimate denitrification in wetlands. In addition, we will discuss how evaluating soil isotopes as a possible indicator of denitrification may contribute to large-scale surveys, such as the National Wetland Condition Assessment (NWCA). We are currently evaluating δ15N soil isotopes in soils collected from approximately 900 probability-selected wetland sites from across the conterminous United States as part of the NWCA.