Nitrogen fixation in the high arctic tundra at Sarcpa Lake, Northwest Territories

The acetylene reduction assay was used to examine biological nitrogen fixation in the high arctic tundra at Sarcpa Lake, Northwest Territories (68°32′ N, 83°19′ W). The highest rates of acetylene reduction (9.37 ± 3.19 μmol C 2 H 4 m −2 h −1 ) were in habitats that had a high density of the legumes...

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Bibliographic Details
Published in:Canadian Journal of Botany
Main Authors: Karagatzides, Jim D., Lewis, Martin C., Schulman, Herbert M.
Format: Article in Journal/Newspaper
Language:French
Published: Canadian Science Publishing 1985
Subjects:
Online Access:http://dx.doi.org/10.1139/b85-131
http://www.nrcresearchpress.com/doi/pdf/10.1139/b85-131
Description
Summary:The acetylene reduction assay was used to examine biological nitrogen fixation in the high arctic tundra at Sarcpa Lake, Northwest Territories (68°32′ N, 83°19′ W). The highest rates of acetylene reduction (9.37 ± 3.19 μmol C 2 H 4 m −2 h −1 ) were in habitats that had a high density of the legumes Oxytropis maydelliana, O. arctobia, and Astragalus alpinus. Nitrogen fixation in the wet soils along the shore of a small lake was similar (8.87 ± 4.35 μmol C 2 H 4 m −2 h −1 ) because of the blue-green alga Nostoc, which associates with mosses. Free-living blue-green algae and lichens made insignificant contributions to the total nitrogen fixation budget because they were uncommon and fixed nitrogen at a slower rate. Nitrogen-fixing lichens in the area included Stereocaulon arenarium and S. rivulorum. It is concluded that legumes have a significant input to the biological nitrogen fixation budget at Sarcpa Lake.