Biogeochemistry

, Volume 48, Issue 2, pp 165–184

Nitrogen solutes in an Adirondack forested watershed: Importance of dissolved organic nitrogen

  • Michael R. McHale
  • Myron J. Mitchell
  • Jeffrey J. McDonnell
  • Christopher P. Cirmo
Article

DOI: 10.1023/A:1006121828108

Cite this article as:
McHale, M.R., Mitchell, M.J., McDonnell, J.J. et al. Biogeochemistry (2000) 48: 165. doi:10.1023/A:1006121828108

Abstract

Nitrogen (N) dynamics were evaluated from 1 June 1995 through 31 May 1996 within the Arbutus Lake watershed in the Adirondack Mountains of New York State, USA. At the Arbutus Lake outlet dissolved organic nitrogen (DON), NO3- and NH4+ contributed 61%, 33%, and 6% respectively, to the total dissolved nitrogen (TDN) flux (259 mol ha-1 yr-1). At the lake inlet DON, NO3-, and NH4- constituted 36%, 61%, and 3% respectively, of TDN flux (349 mol ha-1 yr-1). Differences between the factors that control DON, NO3+, and NH4+ stream water concentrations were evaluated using two methods for estimating annual N flux at the lake inlet. Using biweekly sampling NO3- and NH4+ flux was 10 and 4 mol ha-1 yr-1 respectively, less than flux estimates using biweekly plus storm and snowmelt sampling. DON flux was 18 mol ha-1 yr-1 greater using only biweekly sampling. These differences are probably not of ecological significance relative to the total flux of N from the watershed (349 mol ha-1 yr-1). Dissolved organic N concentrations were positively related to discharge during both the dormant (R2 = 0.31; P < 0.01) and growing season (R2 = 0.09; P < 0.01). There was no significant relationship between NO3- concentration and discharge during the dormant season, but a significant negative relationship was found during the growing season (R2 = 0.29; P < 0.01). Biotic controls in the growing season appeared to have had a larger impact on stream water NO3- concentrations than on DON concentrations. Arbutus Lake had a major impact on stream water N concentrations of the four landscape positions sampled, suggesting the need to quantify within lake processes to interpret N solute losses and patterns in watershed-lake systems.

Adirondack Mountainstotal organic nitrogenhydrologynitrogen retentionnitrogen saturationwatershed

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Michael R. McHale
    • 1
  • Myron J. Mitchell
    • 3
  • Jeffrey J. McDonnell
    • 1
  • Christopher P. Cirmo
    • 4
  1. 1.College of Environmental Science and Forestry, Faculty of ForestryState University of New YorkU.S.A.
  2. 2.U.S. Geological SurveyTroyU.S.A.; phone
  3. 3.College of Environmental Science and Forestry, Faculty of Environmental and Forest BiologyState University of New YorkSyracuseU.S.A.
  4. 4.Department of GeologyState University of New York at CortlandCortlandU.S.A.