, Volume 8, Issue 4, pp 442–453

Nitrogen Retention, Removal, and Saturation in Lotic Ecosystems

Mini review

DOI: 10.1007/s10021-003-0143-y

Cite this article as:
Bernot, M.J. & Dodds, W.K. Ecosystems (2005) 8: 442. doi:10.1007/s10021-003-0143-y


Increased nitrogen (N) loading to lotic ecosystems may cause fundamental changes in the ability of streams and rivers to retain or remove N due to the potential for N saturation. Lotic ecosystems will saturate with sustained increases in the N load, but it is unclear at what point saturation will occur. Rates of N transformation in lotic ecosystems will vary depending on the total N load and whether it is an acute or chronic N load. Nitrogen saturation may not occur with only pulsed or short-term increases in N. Overall, saturation of microbial uptake will occur prior to saturation of denitrification of N and denitrification will become saturated prior to nitrification, exacerbating increases in nitrate concentrations and in N export downstream. The rate of N export to downstream ecosystems will increase proportionally to the N load once saturation occurs. Long term data sets showed that smaller lotic ecosystems have a greater capacity to remove in-stream N loads, relative to larger systems. Thus, denitrification is likely to become less important as a N loss mechanism as the stream size increases. There is a great need for long-term studies of N additions in lotic ecosystems and clear distinctions need to be made between ecosystem responses to short-term or periodic increases in N loading and alterations in ecosystem functions due to chronic N loading.


nitrogen cyclelotic ecosystemsnitrogen loadingnitrogen retentiondenitrificationprimary productionnitrification

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  1. 1. Department of Biological SciencesUniversity of Notre DameNotre DameUSA
  2. 2.Division of BiologyKansas State UniversityManhattanUSA