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Pelagic nitrogen cycle in an Arctic lake

Thesis/Dissertation ·
OSTI ID:5348989
A mass balance for nitrogen was developed for the water column of Toolik Lake and the isotope tracers /sup 15/N and /sup 14/C were used to examine the phytoplankton ecology with respect to dissolved inorganic nitrogen (ammonium and nitrate). The nutrient budget showed an oligotrophic ecosystem with important flux terms few and small in magnitude. Nitrogen input was primarily from inflowing rivers and was dominated by the dissolved organic fraction. Ammonium release from sediment provided the only other major source of nitrogen to the lake water. Toolik acted as a nitrogen sink, trapping 18% of the annual input. Retention was almost exclusively (98%) as dissolved organic nitrogen. Tracer experiments suggested chronic nitrogen deficiency in the phytoplankton, but indigenous populations were well-adapted for utilizing characteristically low levels of nutrient.
Research Organization:
Alaska Univ., Fairbanks (USA)
OSTI ID:
5348989
Country of Publication:
United States
Language:
English