Burgin, A. J., S. K. Hamilton, W. Gardner, and M. McCarthy. 2013. Nitrate reduction, denitrification, and dissimilatory nitrate reduction to ammonium in wetland sediments. Pages 519-537 in R. D. Delaune, R. Reddy, C. J. Richardson, and P. Megonigal, eds. Methods in biogeochemistry of wetlands. Soil Science Society of America, Madison, Wisconsin, USA.

Citable PDF link: https://lter.kbs.msu.edu/pub/3142

Nitrate loading to aquatic ecosystems has increased dramatically in response to anthropogenic N pollution. Nitrate can be removed from aquatic ecosystems through a variety of processes including denitrification and dissimilatory nitrate reduction to ammonium (DNRA). In this chapter, we present two methods used in combination with the stable isotope of NO3− (15NO3−) to quantify the relative importance of DNRA and denitrification to overall NO3− uptake. First, we describe how continuous flow-through sediment cores can be used for controlled manipulations involving the addition of 15NO3− and measurement of resultant 15N2 and 15NH4+ (products of denitrification and DNRA). We also describe the “push–pull” method for determining denitrification and DNRA in situ for a variety of aquatic ecosystem sediment types. Both continuous flow-through cores and push–pull methods can be useful for comparing the N removal capacity of different aquatic ecosystems when full-scale ecosystem isotope additions are impossible due to methodological or resource limitations. Finally, these methods are suitable for comparing the multiple processes that can be responsible for NO3− removal (e.g., denitrification and DNRA). More studies incorporating a comparative analysis of the processes will yield greater understanding of their ecosystem-level importance and controls.

DOI: 10.2136/sssabookser10.c28

Associated Treatment Areas:


Download citation to endnote bibtex

Sign in to download PDF back to index
Sign In