Graduation Date

Spring 2018

Document Type

Thesis

Program

Master of Science degree with a major in Natural Resources, option Forestry, Watershed, & Wildland Sciences

Committee Chair Name

Dr. Andrew Stubblefield

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Alison O'Dowd

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

Dr. Conor Shea

Third Committee Member Affiliation

Community Member or Outside Professional

Subject Categories

Watershed Management

Abstract

The conservation and recovery of anadromous salmonids (Oncorhynchus sp.) depend on stream restoration and protection of freshwater habitats. In-stream large wood dictates channel morphology, increases retention of terrestrial inputs such as organic matter, nutrients and sediment, and enhances the quality of fish habitat. Historic land use/land cover changes have resulted in aquatic systems devoid of large wood. Restoration by placement of large wood jams is intended to restore physical and biological processes. An important question for scientists and restoration managers, in addition to the initial effectiveness of restoration, is the persistence and fate of large wood installations. In this study I compare channel change and large wood attributes on the East Fork of Mill Creek, a tributary of the Smith River in northern California, eight years after a major instream wood placement effort took place. I compared my results with previously published data from a few months before and one year after large wood installation.

Since the introduction of complex wood jams to East Fork Mill Creek in 2008, this study found an overall increase in floodplain connectivity, bankfull width, and lower channel gradient leading to an increase in hydraulic complexity. Key log jams designs were found to be self-sustaining; creating cover and resting habitat for adult and juvenile salmonids such as side channel access. Furthermore, self-sustaining log jams further improved rearing habitat for juvenile salmonids by trapping and sorting sediments exposing spawning gravel suitable for Chinook, Coho and coastal rainbow trout. The results observed in this study support several common long-term goals. Future restoration efforts in areas equivalent to East Fork Mill Creek with similar long-term goals may find complex log jams, comparable to the log jams installed in this study, benefiting their project area

Citation Style

APA

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