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Stream habitat classification and restoration in the Blue Mountians of northeast Oregon

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dc.contributor.advisor Liss, William J.
dc.creator Ebersole, Joseph Lamar
dc.date.accessioned 2012-11-20T22:50:03Z
dc.date.available 2012-11-20T22:50:03Z
dc.date.copyright 1994-06-01
dc.date.issued 1994-06-01
dc.identifier.uri http://hdl.handle.net/1957/35152
dc.description Graduation date: 1995 en_US
dc.description.abstract The restoration of rivers and streams should be based on a strong conceptual framework. Streams are developing systems. As such, streams exhibit temporal behaviors that change with changing stream environments. Underlying the dynamic development of streams is potential capacity. Streams express this capacity as an array of habitats over time and across the landscape. Human land uses in the western United States have rapidly altered aquatic habitats as well as the processes that shape habitat. As a result, the diversity of native fishes and their habitats has been suppressed. Restoration is fundamentally about allowing stream systems to re-express their capacities. Four steps are provided to guide stream restoration activities. Key tasks include: identification of the historic patterns of habitat development; protection of the developmental diversity that remains; local application of specific knowledge about suppressive factors; classification of sensitive, critical or refugium habitats; release of anthropogenic suppression; and monitoring of biotic response to habitat change. Applying these concepts, I describe potential habitat refugia for aquatic organisms in the Joseph Creek basin in the Blue Mountains of northeast Oregon. Five valley segment classes, differing in valley corridor landforms, are described. Of these, low-gradient wide alluvial valleys have been most altered by human land use. Riparian vegetation has been extensively removed or altered in alluvial valleys. Currently, stream habitats are structurally depauperate, and warm to temperatures well above thermal tolerances of native salmonids. Potential refugia for native coldwater fishes in these valleys include patches of complex habitat within stream reaches. Reaches fenced to exclude domestic livestock exhibit narrower channels, more pools, and higher frequencies of stable vegetated banks than nearby unfenced reaches. During summer low flow periods, cold groundwater seeping into and accumulating in stream channels forms "cold pools". Cold pools provide potential seasonal refuge for coldwater fish at microhabitat scales. Cold pools are associated with channel complexity, and are more frequent in reaches with vigorous riparian vegetation. Seven classes of cold pools are described. Cold pool classes differ in minimum temperature, maximum depth and volume. Distributions of cold pool classes between valley segment classes suggest that valley geomorphology in addition to local channel form may influence development of certain cold pool types. Although refugia at the microhabitat to reach scales are important, the context within which remnant or refugium habitats and associated relict populations are maintained may ultimately determine the persistence of those species and habitats. In managed landscapes, protection and restoration of habitats at many scales may be necessary if we are to best insure the persistence of native species. en_US
dc.language.iso en_US en_US
dc.subject.lcsh Pacific salmon -- Oregon -- Joseph Creek Watershed en_US
dc.subject.lcsh Fish habitat improvement -- Oregon -- Joseph Creek Watershed en_US
dc.subject.lcsh Stream conservation -- Oregon -- Joseph Creek Watershed en_US
dc.subject.lcsh Restoration ecology -- Oregon -- Joseph Creek Watershed en_US
dc.subject.lcsh Watershed management -- Oregon -- Joseph Creek Watershed en_US
dc.title Stream habitat classification and restoration in the Blue Mountians of northeast Oregon en_US
dc.type Thesis/Dissertation en_US
dc.degree.name Master of Science (M.S.) in Fisheries Science en_US
dc.degree.level Master's en_US
dc.degree.discipline Agricultural Sciences en_US
dc.degree.grantor Oregon State University en_US
dc.description.digitization File scanned at 300 ppi (Monochrome, 8-bit Grayscale) using ScandAll PRO 1.8.1 on a Fi-6670 in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR. en_US
dc.description.peerreview no en_us

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