Potential Denitrification Activity in the Landscape of a Western Alaska Drainage Basin
Pinay G, O'Keefe T, Edwards R, Naiman RJ. 2003. Potential Denitrification Activity in the Landscape of a Western Alaska Drainage Basin. Ecosystems. 6(4):336-343
We examined denitrification potentials in six of the major landscape structure (riparian soils of both meandering and braided streams, peat lands, coniferous flats, alder slopes, and groundwater seeps) of the Lake Nerka catchment in southwest Alaska. We found significant potential denitrifying activity in all the soils of the main landscape patch types of the Lake Nerka catchment. The lowest potential denitrifying activity was measured in the peat lands. A highly significant relationship was found between soil organic matter and potential denitrification activity in three landforms-coniferous flats, groundwater seeps, and riparian soils of meandering streams. These three landscape structures also had the highest denitrifying potential. The finer soils of riparian zones along spawning streams, which corresponded to meandering streams, showed a significantly higher potential denitrification activity than the coarse riparian soils along nonspawning streams. These nonspawning streams corresponded to braided streams, where finer sediments were not as prevalent. Therefore, if this high potential denitrification measured in riparian soils of spawning streams is combined with large inputs of nitrate to anaerobic sites, it can result in 15 N signatures that mimic that of the marine-derived nitrogen provided by Pacific salmon in these Alaskan ecosystems.
- Type
- Journal Article
- Authors
- Pinay, G; O'Keefe, T; Edwards, R; Naiman, Robert
- Units
- GLBA , KLGO , SEAN , SITK
- Keywords
- Carcasses, Coho Salmon, denitrification, Dynamics, History, Landscape, Nitrogen, Pacific Salmon, Riparian Zone, Salmon, sashin creek, Soil, southeastern riparian forest