Distribution of phytobenthos in the Yakima River basin, Washington, in relation to geology, land use and other environmental factors

Canadian Journal of Fisheries and Aquatic Sciences
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Abstract

Benthic-algal distributions in the Yakima River, Washington, basin were, examined in relation to geology, land use, water chemistry, and stream habitat using indicator-species classification (TWINSPAN) and canonical correspondence analysis (CCA). Algal assemblages identified byTWINSPAN were each associated with a narrow range of water-quality conditions. In the Cascade geologic province, where timber harvest and grazing are the dominant land uses, differences in community structure (CCA site scores) and concentrations of major ions (Ca and Mg) and nutrients (solute P, SiO2 and inorganic N) varied with dominant rock type of the basin. In agricultural areas of the Columbia Plateau province, differences in phytobenthos structure were based primarily on the degree of enrichment of dissolved solids, inorganic N, and solute P from irrigation-return flows and subsurface drainage. Habitat characteristics strongly correlated with community structure included reach altitude, turbidity, substratum embeddedness (Columbia Plateau), large woody-debris density (Cascade Range), and composition and density of the riparian vegetation. Algal biomass (AFDM) correlated with composition and density of the riparian vegetation but not with measured chemical-constituent concentrations. Nitrogen limitation in streams of the Cascade Range favored nitrogen-fixing blue-green algae and diatoms with endosymbiotic blue-greens, whereas nitrogen heterotrophs were abundant in agricultural areas of the Columbia Plateau.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Distribution of phytobenthos in the Yakima River basin, Washington, in relation to geology, land use and other environmental factors
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/f95-108
Volume 52
Issue 5
Year Published 1995
Language English
Publisher Department of Fisheries and Oceans
Publisher location Ottawa
Contributing office(s) Washington Water Science Center
Description 22 p.
First page 1108
Last page 1129
Online Only (Y/N) N
Additional Online Files (Y/N) N