Skip to Main Content
Stream denitrification across biomes and its response to anthropogenic nitrate loadingAuthor(s): Patrick J Mulholland; Ashely M. Helton; Geoffrey C. Poole; Robert O. Hall; Stephen K. Hamilton; Bruce J. Peterson; Jennifer L. Tank; Linda R. Ashkenas; Lee W. Cooper; Clifford N. Dahm; Walter K. Dodds; Stuart E.G. Findlay; Stanley V. Gregory; Nancy B. Grimm; Sherri L. Johnson; William H. McDowell; Judy L. Meyer; H. Maurice Valett; Jackson R. Webster; Clay P. Arango; Jake J. Beaulieu; Melody J. Bernot; Amy J. Burgin; Chelsea L. Crenshaw; Laura T. Johnson; B.R. Niederlehner; Jonathan M. O'Brien; Jody D. Potter; Richard W. Sheibley; Daniel J. Sobota; Suzanne M. Thomas
Source: Nature. 452: 202-206
Publication Series: Scientific Journal (JRNL)
PDF: View PDF (1.6 MB)
DescriptionAnthropogenic addition of bioavailable nitrogen to the biosphere is increasing, and terrestrial ecosystems are becoming increasingly nitrogen-saturated, causing more bioavailable nitrogen to enter groundwater and surface waters. Large-scale nitrogen budgets show that an average of about 20 to 25 percent of the nitrogen added to the biosphere is exported from rivers to the ocean or inland basins, indicating that substantial sinks for nitrogen must exist in the landscape. Streams and rivers may themselves be important sinks for bioavailable nitrogen owing to their hydrological connections with terrestrial systems, high rates of biological activity, and streambed sediment environments that favour microbial denitrification. Here we present data from nitrogen stable isotope tracer experiments across 72 streams and 8 regions representing several biomes. We show that total biotic uptake and denitrification of nitrate increase with stream nitrate concentration, but that the efficiency of biotic uptake and denitrification declines as concentration increases, reducing the proportion of instream nitrate that is removed from transport. Our data suggest that the total uptake of nitrate is related to ecosystem photosynthesis and that denitrification is related to ecosystem respiration. In addition, we use a stream network model to demonstrate that excess nitrate in streams elicits a disproportionate increase in the fraction of nitrate that is exported to receiving waters and reduces the relative role of small versus large streams as nitrate sinks.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationMulholland, Patrick J,; Helton, Ashely M.; Poole, Geoffrey C.; Hall, Robert O., Jr.; Hamilton, Stephen K.; Peterson, Bruce J.; Tank, Jennifer L.; Ashkenas, Linda R.; Cooper, Lee W.; Dahm, Clifford N.; Dodds, Walter K.; Findlay, Stuart E.G.; Gregory, Stanley V.; Grimm, Nancy B.; Johnson, Sherri L.; McDowell, William H.; Meyer, Judy L.; Valett, H. Maurice; Webster, Jackson R.; Arango, Clay P. Beaulieu, Jake J.; Bernot, Melody J.; Burgin, Amy J.; Crenshaw, Chelsea L.; Johnson, Laura T.; Niederlehner, B.R.; O''Brien, Jonathon M.; Potter, Jody D.; Sheibley, Richard W.; Sobota, Daniel J.; Thomas, Suzanne M. 2008. Stream denitrification across biomes and its response to anthropogenic nitrate loading. Nature. 452: 202-206
KeywordsStream denitrification, water nitrate and nitrite
- Stream denitrification across biomes and its response to anthropogenic nitrate loading
- Give and Take: A Watershed Acid Rain Mitigation Experiment Increases Baseflow Nitrogen Retention but Increases Stormflow Nitrogen Export
Nitrate removal in stream ecosystems measured by 15N addition experiments: denitrification
XML: View XML