Record Details
Benthic algal flora of four rivers of the middle Willamette River Basin
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Benthic algal flora of four rivers of the middle Willamette River Basin |
| Names |
Todd, Leona Esther
(creator) Phinney, Harry K. (advisor) |
| Date Issued | 1973-05-02 (iso8601) |
| Note | Graduation date: 1973 |
| Abstract | Fresh-water benthic river algae were collected from selected sites in Willamette River tributaries; two sampling sites were in the Yamhill River system and four sampling sites were in the Santiam River system. Twelve samples were taken at each collection site in the Yamhill River system at approximately monthly intervals from June 1967 through June 1968. Fourteen samples were taken at all sampling sites, excepting one, in the Santiam River system at approximately monthly intervals from June 1967 through September 1968. A total of 24 genera of benthic algae other than diatoms were identified from the two river systems, 14 genera from the Yamhill River system and 22 genera from the Santiam River system. Six genera were common to both river systems, Anabaena, Oseillatoria, Schizothrix, Spirulina, Mougeotia and Oedogonium. Ten genera were found at only one of the collecting stations. By far, the most common genus was Schizothrix; it was found in 92 percent of the samples. The greatest diversity in the samples was found in the August 27, 1967 Santiam and September 2, 1967 Yamhill samples. The smallest number of genera were found in the March collections. A total of 14,986 individual diatoms were identified and counted. Sixty-two species of diatoms were found in this study; 55 were found in the Yamhill River system and 57 were found in the Santiam River system. Of the 13 species not found in common in the two collecting sites in the Yamhill River system, all excepting Fragilaria vaucheriae were found in very low numbers and in only a few samples. Those species not occurring in common in the Santiam River system were found in low numbers excepting for Cymbella affinis, C. ventricosa and Fragilaria capucina. The Yamhill River system and Santiam River system had 50 species in common and 24 species were collected at all six sampling stations. Statistical analyses of the diatom data were done by using *AIDONE and *AIDN computer programs. Comparative studies of diversity using Simpson's Diversity Index (SDI), dominance, Redundancy Index (R'), similarity, Similarity Index (SIMI) and niche breadth were made. Comparisons were made within and between rivers. The highest diversity and the lowest dominance occurred in the North Yamhill River; the highest dominance and the lowest diversity occurred at the Lebanon Dam on the South Santiam River. Stations on the Yamhill River system had a greater mean number of species per sample than the Santiam River system stations. In general, species with high niche breadth values in one river system also had high niche breadth values in the other system. A greater similarity within a river system than between the two river systems was shown. |
| Genre | Thesis/Dissertation |
| Topic | Freshwater algae -- Oregon -- Willamette River Watershed |
| Identifier | http://hdl.handle.net/1957/44840 |
