Nitrogen cycling in Lake Wingra

Journal Article · Thu Jan 01 04:00:00 EST 1976 · J. Environ. Qual.; (United States)

DOI:https://doi.org/10.2134/jeq1976.00472425000500020015x· OSTI ID:7340535

Isirimah, N O; Keeney, D R; Dettmann, E H

Monitoring of the forms of N in water and sediment, and investigations of N cycling in Lake Wingra, a small, eutrophic, hardwater lake in southern Wisconsin, were conducted. Nitrification in the waters appeared to be by heterotrophs, while autotrophic nitrification dominated in the sediments. Rapid turnover of /sup 15/N-NH/sup +//sub 4/ occurred in the waters, but not in the sediments, while /sup 15/N-NO/sub 3//sup -/ turnover was slow in the waters. In the sediments, denitrification and immobilization of /sup 15/N-NO/sub 3//sup -/ was rapid. About 80 percent of the added /sup 15/N-NO/sub 3//sup -/ was denitrified, the remainder being immobilized. Detrital-/sup 15/N was slowly mineralized in the sediments. Sediment-water interchange occurred at a significant rate. About 40 mu g NH/sub 4//sup +/-N/liter sediment/day was formed from organic-N, and subsequently released to the overlying water. Estimates of the overall average N content in various compartments indicated that about 50 percent of the ''available'' N was in the water, 20 percent in the macrophytes, and 30 percent in the sediments, while over 97 percent of the total N in the lake (to 30 cm sediment depth) was as sediment organic N. Consideration of seasonal changes in the NH/sub 4//sup +/-N content of the sediments gave an average release rate of NH/sub 4//sup +/-N of 7 to 29 mg m/sup -2/ day/sup -1/. This would supply from 3 to 14 metric tons of N to the lake water yearly.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 7340535
• Journal Information: J. Environ. Qual.; (United States), Journal Name: J. Environ. Qual.; (United States) Vol. 5:2; ISSN JEVQA
• Country of Publication: United States
• Language: English

Related Subjects

520100* -- Environment
Aquatic-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
AQUATIC ECOSYSTEMS
ECOSYSTEMS
GREAT LAKES REGION
ISOTOPES
LABELLED COMPOUNDS
LAKES
LIGHT NUCLEI
NITROGEN 15
NITROGEN CYCLE
NITROGEN ISOTOPES
NORTH AMERICA
NUCLEI
NUTRIENTS
ODD-EVEN NUCLEI
PRODUCTIVITY
SEDIMENTS
STABLE ISOTOPES
SURFACE WATERS
USA
WATER QUALITY
WISCONSIN