Influence of stream size on ammonium and suspended particulate nitrogen processing

• DOI: 10.4319/lo.2001.46.1.0001
• Publication Date: 2010-06-30T20:48:27Z
• Authors: Wilfred M. Wollheim; Bruce J. Peterson; Linda A. Deegan; John E. Hobbie; Beth Hooker; William B. Bowden; Kenneth J. Edwardson; David B. Arscott; Anne E. Hershey; Jacques Finlay
• Keywords: TRACER; Litter

We used 15 NH 4 tracer additions to determine travel distances of ammonium (NH4 ) and suspended particulate organic nitrogen (SPON) in six streams ranging from second fifth order located within a single watershed on the North Slope Alaska. Based distribution N stored stream bottom compartments (primary producers or grazers), we estimated lengths. two‐compartment model estimate length SPON based source SPO water column. Both lengths (S w S p , respectively) increased with discharge primarily due changes depth velocity. Variation vertical mass transfer coefficient ( v f both did occur among but was not related size relatively small compared change physical characteristics. Thus, Kuparuk watershed, gradients outweighed biological chemical as controls length. The one exception fertilized reach, where phosphorus fertilization greatly activity processing unaltered streams. Longitudinal major driving variables such litter inputs, debris dams, shading are absent Arctic, perhaps explaining uniform ‐ . Watersheds other biomes may show differing degrees versus biological/chemical controls. A conceptual is presented for comparing relative strength these different watersheds. Strong relationships between should aid development models nutrient dynamics.