Biogeochemistry

, Volume 120, Issue 1–3, pp 239–257

Nitrate uptake dynamics of surface transient storage in stream channels and fluvial wetlands

  • W. M. Wollheim
  • T. K. Harms
  • B. J. Peterson
  • K. Morkeski
  • C. S. Hopkinson
  • R. J. Stewart
  • M. N. Gooseff
  • M. A. Briggs
Article

DOI: 10.1007/s10533-014-9993-y

Cite this article as:
Wollheim, W.M., Harms, T.K., Peterson, B.J. et al. Biogeochemistry (2014) 120: 239. doi:10.1007/s10533-014-9993-y

Abstract

River systems are important regulators of anthropogenic nitrogen flux between land and ocean. Nitrogen dynamics in small headwater streams have been extensively measured, whereas less is known about contributions of other components of stream networks to nitrogen removal, including larger streams or fluvial wetlands. Here, we quantified nitrate reaction rates in higher-order stream channels and in surface transient storage (STS) zones (sub-systems with greater water residence time than the main channel) of the Ipswich River watershed, a temperate basin characterized by suburban development. We characterized uptake in STS both within higher-order stream channels and in fluvial wetlands that remain connected to advective fluxes but not constrained within channels. We compare reaction rates in these systems to those previously measured in headwater streams in the same basin. We found that (1) nitrate reaction rates (as uptake velocity, υf) in higher-order streams (n = 2) differed from each other but were consistent with previous estimates from headwater streams, (2) nitrate reaction rates in STS zones within higher-order stream channels (n = 2) were higher than rates estimated at the whole-stream scale, (3) ambient nitrate reaction rates in fluvial wetland STS (n = 7) were high but comparable to headwater streams with low nitrate concentration, (4) nitrate reaction rates were higher in fluvial wetland STS compared to headwater stream channels at elevated nitrate concentration, and (5) efficiency loss (EL) similar to that found in headwater streams was also apparent in fluvial wetlands. These results indicate that STS are potential hotspots of biogeochemical activity and should be explicitly integrated into network scale biogeochemical models. Further, experimental evidence of EL in fluvial wetlands suggests that the effectiveness of STS to retain N may decline if N loading increases.

Keywords

Transient storage zones Nitrogen cycling Denitrification River network Fluvial wetlands Efficiency loss 

Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • W. M. Wollheim
    • 1
    • 2
  • T. K. Harms
    • 3
  • B. J. Peterson
    • 4
  • K. Morkeski
    • 4
  • C. S. Hopkinson
    • 5
  • R. J. Stewart
    • 2
  • M. N. Gooseff
    • 6
  • M. A. Briggs
    • 7
  1. 1.Department of Natural Resources and EnvironmentUniversity of New HampshireDurhamUSA
  2. 2.Institute for the Study of Earth, Oceans, and SpaceUniversity of New HampshireDurhamUSA
  3. 3.Institute of Arctic Biology and Department of Biology & WildlifeUniversity of Alaska FairbanksFairbanksUSA
  4. 4.Ecosystems CenterMarine Biological LaboratoryWoods HoleUSA
  5. 5.Department of Marine ScienceUniversity of GeorgiaAthensUSA
  6. 6.Department of Civil & Environmental EngineeringColorado State UniversityFort CollinsUSA
  7. 7.Office of Groundwater, Branch of GeophysicsU.S. Geological SurveyStorrsUSA

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