First Advisor

Mike Ghedotti

College

Regis College

Degree Name

MS Environmental Biology

Department (optional)

Biology

Document Type

Thesis - Open Access

Number of Pages

68 pages

Abstract

Historically, salmon have provided essential marine nutrients to land-locked habitats during their spawning migration. Many plant and animal species are dependent on this source of nutrients for survival and growth, and their absence has been shown to dramatically alter these terrestrial communities. Dams have been built throughout much of the historic range of salmon, cutting terrestrial ecosystems off from the flow of marine nutrients they depend on, leading to degradation of wetland habitats and reduced predator abundance. With time, however, concern for the decreased salmon abundance has resulted in organized efforts to remove dams in historically important salmon spawning areas, but the effects of removal on stream-associated ecosystems remain unknown.

The Rogue River in southern Oregon offers a unique opportunity to investigate the impact of salmon reintroduction on surrounding herbaceous vegetation since it has had eight dams removed since 2003, but also has remaining dammed portions that can serve as controls. I predict that herbaceous plant species richness and above-ground biomass will increase in areas where salmon are reintroduced compared to areas where the rivers remain dammed. By comparing herbaceous vegetation richness and biomass along two tributary streams where salmon have been reintroduced to two tributary streams where dams remain, I will be able to investigate differences in community structure and determine if salmon reintroduction has had positive impacts on formally degraded habitats. Wetlands, such as those surrounding tributary streams, provide 14 essential habitat for numerous plant, bird, and insect species, and their health is imperative to maintaining surrounding ecosystems that are functional and productive

Date of Award

Spring 2018

Rights Statement

All content in this Collection is owned by and subject to the exclusive control of Regis University and the authors of the materials. It is available only for research purposes and may not be used in violation of copyright laws or for unlawful purposes. The materials may not be downloaded in whole or in part without permission of the copyright holder or as otherwise authorized in the “fair use” standards of the U.S. copyright laws and regulations.

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