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Salmon and Alder as Nitrogen Sources to Riparian Forests in a Boreal Alaskan Watershed
Oecologia (2002)
  • James M. Helfield, Western Washington University
  • Robert J Naiman
Anadromous Pacific salmon (Oncorhynchus spp.) transport marine-derived nitrogen (MDN) to the rivers in which they spawn. Isotopic analyses of riparian vegetation in a boreal Alaskan watershed indicate that trees and shrubs near spawning streams derive -24-26% of their foliar nitrogen (N) from salmon. Basal area growth of white spruce (Picea glauca ) is enhanced at sites receiving MDN inputs. This marine N subsidy ap­pears to be less important to riparian ecosystems where symbiotic N fixation by alder (Alnus crispa) is prevalent, although salmon carcasses may nonetheless be an impor­tant source of other marine-derived nutrients affecting productivity in these forests. These findings illustrate the complexity of interactions surrounding riparian forests and the interconnectedness of river and riparian ecosys­tems.
  • Alnus crispa,
  • Marine-derived nutrients,
  • Oncorhynchus,
  • Picea glauca,
  • Riparian,
  • Stable isotopes
Publication Date
December, 2002
Publisher Statement
Published by: Springer in cooperation with International Association for Ecology Stable URL:
Citation Information
James M. Helfield and Robert J Naiman. "Salmon and Alder as Nitrogen Sources to Riparian Forests in a Boreal Alaskan Watershed" Oecologia Vol. 133 Iss. 4 (2002)
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