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• 71. [Article] Drop it like it’s Hot : Combining DTS and Temperature Modeling to Evaluate Stream Restoration on the Middle Fork of the John Day River

  Temperature is a key factor for salmonid health and is an important restoration metric on the Middle Fork of the John Day River in northeast Oregon. In the past century, dredge mining, deforestation, and ...

  Citation × Citation Citation Abstract Copy Title: Drop it like it’s Hot : Combining DTS and Temperature Modeling to Evaluate Stream Restoration on the Middle Fork of the John Day River Author: Hall, Austin (Austin Garrett) Temperature is a key factor for salmonid health and is an important restoration metric on the Middle Fork of the John Day River in northeast Oregon. In the past century, dredge mining, deforestation, and overgrazing have degraded stream habitat and resulted in greater daytime stream temperatures in the region. Recent restoration efforts have focused on mitigating these anthropogenic disturbances by reestablishing floodplain connections, replanting riparian vegetation, and improving instream habitat features and sediment. To evaluate these restoration projects, the Middle Fork of the John Day River was designated as an intensively monitored watershed in 2008, setting the stage for a 10-year temperature monitoring study. Temperatures measured during the summers of 2013 and 2014 add to the wealth of high resolution distributed temperature sensing (DTS) data collected by Oregon State University and serve as the first post-restoration data for a 2012 restoration project. Utilizing these data in coordination with the model, Heat Source, temperature change from two large restoration projects was quantified. Results from the study emphasize the significance of stream area and riparian vegetation on stream temperatures on the Middle Fork. Phase 2 of the Oxbow Tailings Restoration, completed in 2012, filled over a channel used for past dredge mining activities, reducing stream surface area and restoring the bifurcated channel to its historic south path. Findings show that this project has buffered daily stream temperatures, leading to decreases in maximum and daytime temperatures and increases in nightly temperatures for early August. Maximum and afternoon temperatures were shown to decrease by 0.65 °C and 0.91 °C, respectively, while nightly temperatures increased 0.85 °C. Continuing immediately downstream of the Phase 2 project, Phase 3 is currently in its final stages of construction. Objectives of Phase 3 seek to increase stream meanders, restore vegetation, and reconnect the stream to the adjacent valley and Ruby Creek tributary. Projecting future temperatures shows that the longer, wider restored channel increases afternoon temperature by 0.53 °C. Unlike Phase 2, changes to maximum and nightly temperatures were negligable. Altering the design width and vegetation for the restored channel revealed strong linear correlations to stream temperature, providing a simple tool that can be used to estimate temperature difference for future areal and shading scenarios. Title: Drop it like it’s Hot : Combining DTS and Temperature Modeling to Evaluate Stream Restoration on the Middle Fork of the John Day River Author: Hall, Austin (Austin Garrett) Temperature is a key factor for salmonid health and is an important restoration metric on the Middle Fork of the John Day River in northeast Oregon. In the past century, dredge mining, deforestation, and overgrazing have degraded stream habitat and resulted in greater daytime stream temperatures in the region. Recent restoration efforts have focused on mitigating these anthropogenic disturbances by reestablishing floodplain connections, replanting riparian vegetation, and improving instream habitat features and sediment. To evaluate these restoration projects, the Middle Fork of the John Day River was designated as an intensively monitored watershed in 2008, setting the stage for a 10-year temperature monitoring study. Temperatures measured during the summers of 2013 and 2014 add to the wealth of high resolution distributed temperature sensing (DTS) data collected by Oregon State University and serve as the first post-restoration data for a 2012 restoration project. Utilizing these data in coordination with the model, Heat Source, temperature change from two large restoration projects was quantified. Results from the study emphasize the significance of stream area and riparian vegetation on stream temperatures on the Middle Fork. Phase 2 of the Oxbow Tailings Restoration, completed in 2012, filled over a channel used for past dredge mining activities, reducing stream surface area and restoring the bifurcated channel to its historic south path. Findings show that this project has buffered daily stream temperatures, leading to decreases in maximum and daytime temperatures and increases in nightly temperatures for early August. Maximum and afternoon temperatures were shown to decrease by 0.65 °C and 0.91 °C, respectively, while nightly temperatures increased 0.85 °C. Continuing immediately downstream of the Phase 2 project, Phase 3 is currently in its final stages of construction. Objectives of Phase 3 seek to increase stream meanders, restore vegetation, and reconnect the stream to the adjacent valley and Ruby Creek tributary. Projecting future temperatures shows that the longer, wider restored channel increases afternoon temperature by 0.53 °C. Unlike Phase 2, changes to maximum and nightly temperatures were negligable. Altering the design width and vegetation for the restored channel revealed strong linear correlations to stream temperature, providing a simple tool that can be used to estimate temperature difference for future areal and shading scenarios. Close

• 72. [Article] Nehalem River winter steelhead study

  "The Nehalem and North Fork Nehalem rivers are the major tributaries of Nehalem Bay, an estuary on Oregon's north coast ... The winter steelhead (Salmo gairdneri) and related fisheries of both streams ...

  Citation × Citation Citation Abstract Copy Title: Nehalem River winter steelhead study Author: Knispel, Warren, Weber, Walter, Oregon. Fish Division "The Nehalem and North Fork Nehalem rivers are the major tributaries of Nehalem Bay, an estuary on Oregon's north coast ... The winter steelhead (Salmo gairdneri) and related fisheries of both streams have been the object of a study which began in 1972. Some data from creel surveys were available for the 1970-71 and 1971-72 steelhead seasons and have been used where appropriate. The study was prompted by the apparent failure of hatchery-reared steelhead smolts to contribute in the Nehalem River sport catch at the rate similar to that observed on other coastal streams. There was also concern regarding the status of wild winter steelhead in the Nehalem River." (From Introduction) Title: Nehalem River winter steelhead study Author: Knispel, Warren, Weber, Walter, Oregon. Fish Division "The Nehalem and North Fork Nehalem rivers are the major tributaries of Nehalem Bay, an estuary on Oregon's north coast ... The winter steelhead (Salmo gairdneri) and related fisheries of both streams have been the object of a study which began in 1972. Some data from creel surveys were available for the 1970-71 and 1971-72 steelhead seasons and have been used where appropriate. The study was prompted by the apparent failure of hatchery-reared steelhead smolts to contribute in the Nehalem River sport catch at the rate similar to that observed on other coastal streams. There was also concern regarding the status of wild winter steelhead in the Nehalem River." (From Introduction) Close

• 73. [Article] Phytophthora borealis and Phytophthora riparia, new species in Phytophthora ITS Clade 6

  This is the publisher’s final pdf. The published article is copyrighted by The Mycological Society of America and can be found at: http://www.msafungi.org/.

  Citation × Citation Citation Abstract Copy Title: Phytophthora borealis and Phytophthora riparia, new species in Phytophthora ITS Clade 6 Author: Hansen, Everett M., Sutton, Wendy, Reeser, Paul W. This is the publisher’s final pdf. The published article is copyrighted by The Mycological Society of America and can be found at: http://www.msafungi.org/. Title: Phytophthora borealis and Phytophthora riparia, new species in Phytophthora ITS Clade 6 Author: Hansen, Everett M., Sutton, Wendy, Reeser, Paul W. This is the publisher’s final pdf. The published article is copyrighted by The Mycological Society of America and can be found at: http://www.msafungi.org/. Close

• 74. [Article] Siletz River summer steelhead study

  "The Siletz River ... is the only short coastal stream in Oregon inhabited by a run of what are generally thought to be native summer steelhead. Hatchery-reared progeny from Siletz River stock have been ...

  Citation × Citation Citation Abstract Copy Title: Siletz River summer steelhead study Author: Fortune, John D., Jr, Weber, Walter G., Oregon. Wildlife Commission "The Siletz River ... is the only short coastal stream in Oregon inhabited by a run of what are generally thought to be native summer steelhead. Hatchery-reared progeny from Siletz River stock have been released into and have become established in two other Oregon coastal streams, the Nestucca and Wilson rivers. In 1968 a study on the Siletz River summer steelhead was undertaken. The study continued for five years and terminated June 30, 1973." (From Introduction) Title: Siletz River summer steelhead study Author: Fortune, John D., Jr, Weber, Walter G., Oregon. Wildlife Commission "The Siletz River ... is the only short coastal stream in Oregon inhabited by a run of what are generally thought to be native summer steelhead. Hatchery-reared progeny from Siletz River stock have been released into and have become established in two other Oregon coastal streams, the Nestucca and Wilson rivers. In 1968 a study on the Siletz River summer steelhead was undertaken. The study continued for five years and terminated June 30, 1973." (From Introduction) Close

• 75. [Article] Using Spatial Resampling to Assess Redd Count Survey Length Requirements for Pacific Lamprey

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries ...

  Citation × Citation Citation Abstract Copy Title: Using Spatial Resampling to Assess Redd Count Survey Length Requirements for Pacific Lamprey Author: Schultz, L. D., Colvin, M. E., Mayfield, M. P., Wyss, L. A., Schreck, C. B. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries Society and published by Taylor & Francis. It can be found at: http://www.tandfonline.com/loi/ujfm20#.VJnE_s_AAA. Title: Using Spatial Resampling to Assess Redd Count Survey Length Requirements for Pacific Lamprey Author: Schultz, L. D., Colvin, M. E., Mayfield, M. P., Wyss, L. A., Schreck, C. B. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries Society and published by Taylor & Francis. It can be found at: http://www.tandfonline.com/loi/ujfm20#.VJnE_s_AAA. Close

• 76. [Article] A geographical framework for assessing longitudinal patterns in stream habitat and fish distribution

  New approaches are needed to quantify and understand spatial patterns of stream fishes and their environment. Concepts in riverine ecology emphasize the importance of thermal zones and gradual longitudinal ...

  Citation × Citation Citation Abstract Copy Title: A geographical framework for assessing longitudinal patterns in stream habitat and fish distribution Author: Torgersen, Christian E. New approaches are needed to quantify and understand spatial patterns of stream fishes and their environment. Concepts in riverine ecology emphasize the importance of thermal zones and gradual longitudinal changes in physical habitat and biota, but little is known about spatial variability within the river continuum. I present a conceptual framework for assessing patterns in streams that are difficult to detect using standard site-based approaches to sampling. The ability to detect pattern is defined as the scope, or the ratio of extent (the distance, area, or volume encompassing all sample points) to grain size (the size of an individual sample unit). By increasing the scope and continuity of sampling, I illustrate how greater sampling effort can reveal new patterns and unexpected relationships between stream fishes and their environment. Merging geography and stream ecology, I describe new approaches including remote sensing, multiscale sampling, and extensive surveys for assessing longitudinal patterns in stream habitat and fish distribution. Airborne thermal infrared remote sensing was effective for quantifying spatially continuous patterns of water temperature over a range of scales from channel units (10–50 m) to entire river sections (30–70 km). To examine factors influencing the spatial distribution of larval Pacific lamprey, a benthic fish species, I applied a nested sampling design and determined that stream habitat variables predicted patterns in larval abundance but played different roles at different spatial scales. Increases in the scope of data collection required adaptations in statistical analysis in order to accommodate larger and more complex ecological datasets. I evaluated multivariate ordination techniques with respect to their ability to describe fish community structure and found that nonparametric multivariate smoothing of presence–absence data was highly effective for detecting patterns in heterogeneous fish assemblage data. Spatially continuous analysis presented challenges in extracting patterns from noisy ecological data but provided the opportunity to evaluate distributional patterns over a range of spatial scales. I examined spatial variability of stream fish assemblages and observed that the relative influences of temperature and channel morphology on fish assemblage structure were dependent on the thermal context and the spatial scale of analysis. Title: A geographical framework for assessing longitudinal patterns in stream habitat and fish distribution Author: Torgersen, Christian E. New approaches are needed to quantify and understand spatial patterns of stream fishes and their environment. Concepts in riverine ecology emphasize the importance of thermal zones and gradual longitudinal changes in physical habitat and biota, but little is known about spatial variability within the river continuum. I present a conceptual framework for assessing patterns in streams that are difficult to detect using standard site-based approaches to sampling. The ability to detect pattern is defined as the scope, or the ratio of extent (the distance, area, or volume encompassing all sample points) to grain size (the size of an individual sample unit). By increasing the scope and continuity of sampling, I illustrate how greater sampling effort can reveal new patterns and unexpected relationships between stream fishes and their environment. Merging geography and stream ecology, I describe new approaches including remote sensing, multiscale sampling, and extensive surveys for assessing longitudinal patterns in stream habitat and fish distribution. Airborne thermal infrared remote sensing was effective for quantifying spatially continuous patterns of water temperature over a range of scales from channel units (10–50 m) to entire river sections (30–70 km). To examine factors influencing the spatial distribution of larval Pacific lamprey, a benthic fish species, I applied a nested sampling design and determined that stream habitat variables predicted patterns in larval abundance but played different roles at different spatial scales. Increases in the scope of data collection required adaptations in statistical analysis in order to accommodate larger and more complex ecological datasets. I evaluated multivariate ordination techniques with respect to their ability to describe fish community structure and found that nonparametric multivariate smoothing of presence–absence data was highly effective for detecting patterns in heterogeneous fish assemblage data. Spatially continuous analysis presented challenges in extracting patterns from noisy ecological data but provided the opportunity to evaluate distributional patterns over a range of spatial scales. I examined spatial variability of stream fish assemblages and observed that the relative influences of temperature and channel morphology on fish assemblage structure were dependent on the thermal context and the spatial scale of analysis. Close

• 77. [Article] Multiscale assessment of thermal patterns and the distribution of chinook salmon in the John Day River Basin, Oregon

  This study examined the distribution and behavior of adult spring chinook salmon (Oncorhynchus tshawytscha) related to patterns of stream temperature and physical habitat at channel unit, reach, and basin-wide ...

  Citation × Citation Citation Abstract Copy Title: Multiscale assessment of thermal patterns and the distribution of chinook salmon in the John Day River Basin, Oregon Author: Torgersen, Christian E. This study examined the distribution and behavior of adult spring chinook salmon (Oncorhynchus tshawytscha) related to patterns of stream temperature and physical habitat at channel unit, reach, and basin-wide spatial scales in both a wilderness stream and a disturbed stream in the John Day River basin in northeastern Oregon. Thermal remote sensing of holding and spawning reaches in the upper subbasins of the North Fork and Middle Fork John Day River provided spatially continuous maps of stream temperature. Multiscale associations between salmon and cool-water areas were assessed by overlaying thermal imagery with fish locations mapped during distributional surveys. Chinook salmon were distributed non-uniformly throughout each study area, indicating that salmon selected certain reaches within each subbasin. The coldest reaches available to salmon within the Middle Fork study areas were low gradient, unconstrained reaches where the cooling influence of groundwater flow was the most apparent. In the Middle Fork, the stream currently managed for grazing and timber harvest, water temperature differences were typically 1-2°C within riffle-pool sequences and 3-4°C among reaches. The reach level association between salmon distribution and stream temperature patterns at channel unit and reach level spatial scales was strongest in the warmest study reach, the Middle Fork, and weakest in the coldest study reach, the North Fork. Pools were the preferred habitat for adult spring chinook in both subbasins; however, riffles were used more in the North Fork, the coldest subbasin. This study identified the problems and also the benefits associated with stream temperature patchiness, or discontinuity, both in currently disturbed and in recovering riverine ecosystems. Connectivity among system components in aquatic ecosystems is generally considered necessary for maintaining long-term ecological health. However, it is heterogeneity in the landscape/hydrogeologic template that creates refuge patches in disturbed stream ecosystems, such as those in the John Day River basin. Our observations of thermal refugia occurring at multiple spatial scales, particularly in the Middle Fork John Day River, indicate that, although discontinuity may be an ecological warning sign, refuge patches in streams should also be viewed as expressions of restoration potential because they are functioning remnants of a once continuous, intact hydrologic system. Title: Multiscale assessment of thermal patterns and the distribution of chinook salmon in the John Day River Basin, Oregon Author: Torgersen, Christian E. This study examined the distribution and behavior of adult spring chinook salmon (Oncorhynchus tshawytscha) related to patterns of stream temperature and physical habitat at channel unit, reach, and basin-wide spatial scales in both a wilderness stream and a disturbed stream in the John Day River basin in northeastern Oregon. Thermal remote sensing of holding and spawning reaches in the upper subbasins of the North Fork and Middle Fork John Day River provided spatially continuous maps of stream temperature. Multiscale associations between salmon and cool-water areas were assessed by overlaying thermal imagery with fish locations mapped during distributional surveys. Chinook salmon were distributed non-uniformly throughout each study area, indicating that salmon selected certain reaches within each subbasin. The coldest reaches available to salmon within the Middle Fork study areas were low gradient, unconstrained reaches where the cooling influence of groundwater flow was the most apparent. In the Middle Fork, the stream currently managed for grazing and timber harvest, water temperature differences were typically 1-2°C within riffle-pool sequences and 3-4°C among reaches. The reach level association between salmon distribution and stream temperature patterns at channel unit and reach level spatial scales was strongest in the warmest study reach, the Middle Fork, and weakest in the coldest study reach, the North Fork. Pools were the preferred habitat for adult spring chinook in both subbasins; however, riffles were used more in the North Fork, the coldest subbasin. This study identified the problems and also the benefits associated with stream temperature patchiness, or discontinuity, both in currently disturbed and in recovering riverine ecosystems. Connectivity among system components in aquatic ecosystems is generally considered necessary for maintaining long-term ecological health. However, it is heterogeneity in the landscape/hydrogeologic template that creates refuge patches in disturbed stream ecosystems, such as those in the John Day River basin. Our observations of thermal refugia occurring at multiple spatial scales, particularly in the Middle Fork John Day River, indicate that, although discontinuity may be an ecological warning sign, refuge patches in streams should also be viewed as expressions of restoration potential because they are functioning remnants of a once continuous, intact hydrologic system. Close

• 78. [Article] Fish movement and assemblage dynamics in a Pacific Northwest riverscape

  This study examined fish movements and assemblage dynamics in the Wenaha, Grande Ronde, Snake river system of northeast Oregon and southeast Washington. I investigated the role of fish movement in the ...

  Citation × Citation Citation Abstract Copy Title: Fish movement and assemblage dynamics in a Pacific Northwest riverscape Author: Baxter, Colden V. This study examined fish movements and assemblage dynamics in the Wenaha, Grande Ronde, Snake river system of northeast Oregon and southeast Washington. I investigated the role of fish movement in the dynamics of stream fish assemblages and evaluated relationships between species movement, assemblage structure, and the heterogeneity of habitat at multiple scales within the river network. In doing so, I employed a landscape approach, visualizing the heterogeneity and dynamics of the system as a "riverscape" that sets the stage for the ecology of stream fishes. I quantified fish assemblage dynamics, characterized the nature and extent of movement by representative fish species, and assessed spatial and temporal heterogeneity of stream habitat within the river network. I applied multiple methods, including underwater fish surveys and radio telemetry, and used multiple sampling approaches that allowed me to detect patterns at nested spatial and temporal scales. I found that spatial patterns in fish assemblage structure were highly dynamic over seasonal to diel temporal scales. Seasonal changes in fish assemblage patterns along the length of the river system were primarily driven by the migration of native fishes such as mountain whitefish, bull trout, and largescale suckers. These highly migratory species exhibited a diverse array of movement strategies and often had annual ranges of hundreds of kilometers. The movement of fishes at smaller spatial scales influenced diel dynamics of fish assemblage patterns. Important habitat features at stream, valley segment and channel unit scales were separated spatially, and fish species exhibited a variety of migratory strategies that reflected the complementary use of habitats distributed throughout the riverscape. The importance of fish migration and the dynamic nature of stream fish assemblages and fish habitat relationships should be taken into account in research and conservation of stream fishes. Current conceptual frameworks for stream fish assemblages do not fully reflect the temporal complexity of stream fish life histories or the spatial heterogeneity of stream habitat. I introduce an alternative framework by integrating fish movement into a dynamic perspective of assemblages set within the context of the riverscape, and raise questions regarding the nature of ecological communities. Title: Fish movement and assemblage dynamics in a Pacific Northwest riverscape Author: Baxter, Colden V. This study examined fish movements and assemblage dynamics in the Wenaha, Grande Ronde, Snake river system of northeast Oregon and southeast Washington. I investigated the role of fish movement in the dynamics of stream fish assemblages and evaluated relationships between species movement, assemblage structure, and the heterogeneity of habitat at multiple scales within the river network. In doing so, I employed a landscape approach, visualizing the heterogeneity and dynamics of the system as a "riverscape" that sets the stage for the ecology of stream fishes. I quantified fish assemblage dynamics, characterized the nature and extent of movement by representative fish species, and assessed spatial and temporal heterogeneity of stream habitat within the river network. I applied multiple methods, including underwater fish surveys and radio telemetry, and used multiple sampling approaches that allowed me to detect patterns at nested spatial and temporal scales. I found that spatial patterns in fish assemblage structure were highly dynamic over seasonal to diel temporal scales. Seasonal changes in fish assemblage patterns along the length of the river system were primarily driven by the migration of native fishes such as mountain whitefish, bull trout, and largescale suckers. These highly migratory species exhibited a diverse array of movement strategies and often had annual ranges of hundreds of kilometers. The movement of fishes at smaller spatial scales influenced diel dynamics of fish assemblage patterns. Important habitat features at stream, valley segment and channel unit scales were separated spatially, and fish species exhibited a variety of migratory strategies that reflected the complementary use of habitats distributed throughout the riverscape. The importance of fish migration and the dynamic nature of stream fish assemblages and fish habitat relationships should be taken into account in research and conservation of stream fishes. Current conceptual frameworks for stream fish assemblages do not fully reflect the temporal complexity of stream fish life histories or the spatial heterogeneity of stream habitat. I introduce an alternative framework by integrating fish movement into a dynamic perspective of assemblages set within the context of the riverscape, and raise questions regarding the nature of ecological communities. Close

• 79. [Article] The use of remote sensing and Geographic Information Systems (GIS) in assessing changes in stream morphology and vegetation

  Remote sensing and Geographic Information Systems (GIS) are well known tools for the study of time change analysis in natural systems. However, long-term studies of riparian systems using large-scale aerial ...

  Citation × Citation Citation Abstract Copy Title: The use of remote sensing and Geographic Information Systems (GIS) in assessing changes in stream morphology and vegetation Author: Laliberte, Andrea S. Remote sensing and Geographic Information Systems (GIS) are well known tools for the study of time change analysis in natural systems. However, long-term studies of riparian systems using large-scale aerial photography are less common. The purpose of this project was to combine large scale aerial photography, GIS, Global Positioning Systems (GPS) and ground truthing for conducting a time change analysis study of an eastern Oregon riparian area over a 20 year time period. The objectives were to assess changes in stream morphology and vegetation that occurred in grazed and exclosed areas from 1979 to 1998. In addition, the viability of using large-scale (1:4000) aerial photography combined with GIS/GPS and ground truthing in this study was evaluated. GIS layers of vegetation and stream morphology parameters were developed from geocorrected images. Ground truthing included the collection of vegetation and stream channel measurements. In addition, older aerial photography and previously collected survey data were available for this study. The area of land changing to water and vice versa was calculated over the 41 ha large study area. This area of change (3.65 ha) was slightly larger than the area of no change (3.2 ha). The length of the thalweg and streambank, sinuosity and stream area remained relatively the same. Most of the changes were associated with the islands. Their number decreased, but their area increased, suggesting an increase in stability. Stream width decreased in both grazed and exclosed sites. Shrub and tree cover increased from 1979 to 1998 over the whole study area from 23% to 34%, and this increase was similar in grazed and exclosed sites. The variability of shrub/tree cover within and between the grazed and exclosed sites was high. Topography and stream dynamics appeared to control changes in stream morphology, including erosion, deposition and island formation. We could find no association between the observed changes and the grazing treatment. The use of large-scale aerial photography, GIS and GPS proved to be a powerful tool for detecting change over time and it is expected that these techniques will become more common in rangeland analysis. It is anticipated that the methods used in this study can be applied to and will help in monitoring of other rangeland streams. Title: The use of remote sensing and Geographic Information Systems (GIS) in assessing changes in stream morphology and vegetation Author: Laliberte, Andrea S. Remote sensing and Geographic Information Systems (GIS) are well known tools for the study of time change analysis in natural systems. However, long-term studies of riparian systems using large-scale aerial photography are less common. The purpose of this project was to combine large scale aerial photography, GIS, Global Positioning Systems (GPS) and ground truthing for conducting a time change analysis study of an eastern Oregon riparian area over a 20 year time period. The objectives were to assess changes in stream morphology and vegetation that occurred in grazed and exclosed areas from 1979 to 1998. In addition, the viability of using large-scale (1:4000) aerial photography combined with GIS/GPS and ground truthing in this study was evaluated. GIS layers of vegetation and stream morphology parameters were developed from geocorrected images. Ground truthing included the collection of vegetation and stream channel measurements. In addition, older aerial photography and previously collected survey data were available for this study. The area of land changing to water and vice versa was calculated over the 41 ha large study area. This area of change (3.65 ha) was slightly larger than the area of no change (3.2 ha). The length of the thalweg and streambank, sinuosity and stream area remained relatively the same. Most of the changes were associated with the islands. Their number decreased, but their area increased, suggesting an increase in stability. Stream width decreased in both grazed and exclosed sites. Shrub and tree cover increased from 1979 to 1998 over the whole study area from 23% to 34%, and this increase was similar in grazed and exclosed sites. The variability of shrub/tree cover within and between the grazed and exclosed sites was high. Topography and stream dynamics appeared to control changes in stream morphology, including erosion, deposition and island formation. We could find no association between the observed changes and the grazing treatment. The use of large-scale aerial photography, GIS and GPS proved to be a powerful tool for detecting change over time and it is expected that these techniques will become more common in rangeland analysis. It is anticipated that the methods used in this study can be applied to and will help in monitoring of other rangeland streams. Close

• 80. [Article] Continuous Hydrologic Simulation of Johnson Creek Basin

  Presented at The Oregon Water Conference, May 24-25, 2011, Corvallis, OR.

  Citation × Citation Citation Abstract Copy Title: Continuous Hydrologic Simulation of Johnson Creek Basin Author: Shimota, Richard J., Hadley, Hans R. Presented at The Oregon Water Conference, May 24-25, 2011, Corvallis, OR. Title: Continuous Hydrologic Simulation of Johnson Creek Basin Author: Shimota, Richard J., Hadley, Hans R. Presented at The Oregon Water Conference, May 24-25, 2011, Corvallis, OR. Close