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• 381. [Article] Baseline macroinvertebrate bioassessment of Whychus Creek

  Poster from 2006 Cascades student poster session.

  Citation × Citation Citation Abstract Copy Title: Baseline macroinvertebrate bioassessment of Whychus Creek Author: Parla, Anthony, Zurflu, Erin Poster from 2006 Cascades student poster session. Title: Baseline macroinvertebrate bioassessment of Whychus Creek Author: Parla, Anthony, Zurflu, Erin Poster from 2006 Cascades student poster session. Close

• 382. [Article] Land use and nonpoint source phosphorus pollution in the Dairy-McKay hydrologic unit area of the Tualatin River Basin, Oregon

  Human activities may contribute to the eutrophication of surface waters by providing nutrients to aquatic ecosystems. Phosphorus is frequently identified as a nutrient that is limiting to most aquatic ...

  Citation × Citation Citation Abstract Copy Title: Land use and nonpoint source phosphorus pollution in the Dairy-McKay hydrologic unit area of the Tualatin River Basin, Oregon Author: Wolf, Donald W. Human activities may contribute to the eutrophication of surface waters by providing nutrients to aquatic ecosystems. Phosphorus is frequently identified as a nutrient that is limiting to most aquatic ecosystems under natural conditions. Sources of phosphorus contributing to eutrophic conditions often include nonpoint sources that are dispersed across the landscape. In the Tualatin Basin of Oregon, nonpoint sources have been identified as contributing to phosphorus levels in the Tualatin River that exceed limits established in water quality regulations. The first section of this paper provides a review of relevant literature to explore connections between land use and the sources and transport of nonpoint source phosphorus into the Tualatin Basin. Additionally, where these connections exist, methods to alter existing land use practices to reduce phosphorus contributions are identified. The second section of this paper reviews and analyzes existing data gathered by agencies in the Tualatin Basin to look for evidence of connections between land use and the sources and transport of nonpoint source phosphorus. As one of the most obvious and influential connections, sediment-carried particulate phosphorus is examined both for its influence to the total phosphorus content of streams, and for evidence that it may become more influential as it is transported downstream. Data sets are also examined for seasonal effects and for interactions between phosphorus and other sampled water quality parameters. The third section is an examination and discussion of relevant social issues connected to nonpoint source phosphorus issues in the realization that any solution must be not only technically achievable, but also acceptable to society. Two surveys that attempt to describe the concerns of citizens, one for the general public and one for landowners, are reported. In addition, the problems of establishing regulatory control for a problem whose limits are still undefined is discussed. A philosophy of managementadaptive managementis discussed, and a program for controlling nonpoint source phosphorus in the Tualatin Basin that incorporate adaptive management principles is proposed. Finally, the issues surrounding which segments of society are responsible for paying for control are discussed. Title: Land use and nonpoint source phosphorus pollution in the Dairy-McKay hydrologic unit area of the Tualatin River Basin, Oregon Author: Wolf, Donald W. Human activities may contribute to the eutrophication of surface waters by providing nutrients to aquatic ecosystems. Phosphorus is frequently identified as a nutrient that is limiting to most aquatic ecosystems under natural conditions. Sources of phosphorus contributing to eutrophic conditions often include nonpoint sources that are dispersed across the landscape. In the Tualatin Basin of Oregon, nonpoint sources have been identified as contributing to phosphorus levels in the Tualatin River that exceed limits established in water quality regulations. The first section of this paper provides a review of relevant literature to explore connections between land use and the sources and transport of nonpoint source phosphorus into the Tualatin Basin. Additionally, where these connections exist, methods to alter existing land use practices to reduce phosphorus contributions are identified. The second section of this paper reviews and analyzes existing data gathered by agencies in the Tualatin Basin to look for evidence of connections between land use and the sources and transport of nonpoint source phosphorus. As one of the most obvious and influential connections, sediment-carried particulate phosphorus is examined both for its influence to the total phosphorus content of streams, and for evidence that it may become more influential as it is transported downstream. Data sets are also examined for seasonal effects and for interactions between phosphorus and other sampled water quality parameters. The third section is an examination and discussion of relevant social issues connected to nonpoint source phosphorus issues in the realization that any solution must be not only technically achievable, but also acceptable to society. Two surveys that attempt to describe the concerns of citizens, one for the general public and one for landowners, are reported. In addition, the problems of establishing regulatory control for a problem whose limits are still undefined is discussed. A philosophy of managementadaptive managementis discussed, and a program for controlling nonpoint source phosphorus in the Tualatin Basin that incorporate adaptive management principles is proposed. Finally, the issues surrounding which segments of society are responsible for paying for control are discussed. Close

• 383. [Article] Dead wood dynamics and relationships to biophysical factors, forest history, ownership, and management practices in the Coastal Province of Oregon, USA

  Dead wood patterns and dynamics vary with biophysical factors, disturbance history, ownership, and management practices. Through field and modeling studies, I examined the current and potential future ...

  Citation × Citation Citation Abstract Copy Title: Dead wood dynamics and relationships to biophysical factors, forest history, ownership, and management practices in the Coastal Province of Oregon, USA Author: Kennedy, Rebecca S.H. Dead wood patterns and dynamics vary with biophysical factors, disturbance history, ownership, and management practices. Through field and modeling studies, I examined the current and potential future amounts of dead wood in two landscapes and region-wide in the Coastal Province of Oregon. The objectives of the first study were to (1) determine whether two landscapes with different recent disturbance histories differ in the amount and characteristics of dead wood; and (2) explore relationships between patterns of dead wood in each landscape to potentially related factors including topography. The objectives of the second study were to (1) describe current regional amounts of dead wood; (2) compare dead wood amounts across ownerships; (3) determine relationships between current dead wood amounts and ownership, current and past vegetation conditions, climate, topography, and soils; and (4) evaluate whether the factors related to dead wood patterns differed according to the scale of analysis. The objectives of the third study were to (1) characterize the projected future change in dead wood amounts in a multi-ownership Province; (2) determine the longevity of present-day dead wood of different types and sizes in relation to amendments from management and stand development; and (3) evaluate differences in management approaches in transitional dynamics and long-term patterns of dead wood. In the first study, I sampled logs and snags at four topographic positions (streams, lower slopes, middle slopes, upper slopes) in the Tillamook State Forest and the Siuslaw National Forest. These two landscapes experienced catastrophic fire at different points in recent history. I developed statistical models relating various attributes of dead wood abundance to biophysical variables related to climate, topography, historical vegetation, current vegetation, soils, and ecoregion. I found that the type and timing of disturbance was important to dead wood amounts and characteristics, and that potential source and sink areas for dead wood were related to topographic position. In particular, lower slopes had higher amounts of logs, and upper slopes had higher basal areas of potential source wood, in the form of snags and legacy (pre-fire) stumps. Climatic factors were of greater relative importance to overall gradients of dead wood in the landscape in which fire occurred less recently. In the second study, I analyzed dead wood data from a region-wide systematic grid of field plots according to ownership and biophysical variables at multiple scales of resolution including plots, subwatersheds. Dead wood abundance and types varied greatly among ownerships, with public lands (Forest Service, Bureau of Land Management, State of Oregon) typically having higher amounts of dead wood and more dead wood in the larger size classes than the private lands (forest industry, non-industrial private). I found that the relative influence of ownership, topography, current and historical vegetation, and climate varied with scale of resolution. Current vegetation was of greater relative importance at finer scales of plots and subwatersheds, whereas climate, topography, and historical vegetation were of greater relative importance at coarser scales of watersheds and subbasins. Ownership was important to overall dead wood gradients at all scales considered. In the third study, by simulating stand development and dead wood dynamics under various forest management scenarios over a 300-year period, I was able to examine the long-term effects of management on dead wood abundance in the Coastal Province. I estimated potential upper bounds for future dead wood amounts. Dead wood amounts increased over time on average across the Province, mainly because of policies on public lands, especially the federal lands under the Northwest Forest Plan. Forest industry, under the Oregon Forest Practices Act and assuming retention of all snags at harvest and thinning, maintained amounts of dead wood that were similar to present-day levels, but size classes shifted toward the smaller sizes as existing large legacy dead wood decomposed. Non-industrial private lands showed increases from very low present-day amounts of dead wood. Across the Province, legacy logs and snags remained present for over a century of the simulation period, and buffered effects of intensive management to dead wood amounts. Variation across landscapes in starting conditions meant that contrasting management approaches had differential effects on long-term dead wood dynamics depending on where they were applied. Current amounts of dead wood and live vegetation patterns in the Province resulted from historical fire and logging. Results of this simulation study indicate that recently established policies oriented toward dead wood production and retention, in the absence of fire or other large- or mid-scale disturbances, are likely to result in increases in dead wood amounts that greatly exceed present-day levels. My results suggest that dead wood patterns of abundance will continue to diverge according to land ownership and that management practices that foster dead wood creation are of increasing importance to the long-term abundance of large dead wood as legacy dead wood is lost through decomposition. Title: Dead wood dynamics and relationships to biophysical factors, forest history, ownership, and management practices in the Coastal Province of Oregon, USA Author: Kennedy, Rebecca S.H. Dead wood patterns and dynamics vary with biophysical factors, disturbance history, ownership, and management practices. Through field and modeling studies, I examined the current and potential future amounts of dead wood in two landscapes and region-wide in the Coastal Province of Oregon. The objectives of the first study were to (1) determine whether two landscapes with different recent disturbance histories differ in the amount and characteristics of dead wood; and (2) explore relationships between patterns of dead wood in each landscape to potentially related factors including topography. The objectives of the second study were to (1) describe current regional amounts of dead wood; (2) compare dead wood amounts across ownerships; (3) determine relationships between current dead wood amounts and ownership, current and past vegetation conditions, climate, topography, and soils; and (4) evaluate whether the factors related to dead wood patterns differed according to the scale of analysis. The objectives of the third study were to (1) characterize the projected future change in dead wood amounts in a multi-ownership Province; (2) determine the longevity of present-day dead wood of different types and sizes in relation to amendments from management and stand development; and (3) evaluate differences in management approaches in transitional dynamics and long-term patterns of dead wood. In the first study, I sampled logs and snags at four topographic positions (streams, lower slopes, middle slopes, upper slopes) in the Tillamook State Forest and the Siuslaw National Forest. These two landscapes experienced catastrophic fire at different points in recent history. I developed statistical models relating various attributes of dead wood abundance to biophysical variables related to climate, topography, historical vegetation, current vegetation, soils, and ecoregion. I found that the type and timing of disturbance was important to dead wood amounts and characteristics, and that potential source and sink areas for dead wood were related to topographic position. In particular, lower slopes had higher amounts of logs, and upper slopes had higher basal areas of potential source wood, in the form of snags and legacy (pre-fire) stumps. Climatic factors were of greater relative importance to overall gradients of dead wood in the landscape in which fire occurred less recently. In the second study, I analyzed dead wood data from a region-wide systematic grid of field plots according to ownership and biophysical variables at multiple scales of resolution including plots, subwatersheds. Dead wood abundance and types varied greatly among ownerships, with public lands (Forest Service, Bureau of Land Management, State of Oregon) typically having higher amounts of dead wood and more dead wood in the larger size classes than the private lands (forest industry, non-industrial private). I found that the relative influence of ownership, topography, current and historical vegetation, and climate varied with scale of resolution. Current vegetation was of greater relative importance at finer scales of plots and subwatersheds, whereas climate, topography, and historical vegetation were of greater relative importance at coarser scales of watersheds and subbasins. Ownership was important to overall dead wood gradients at all scales considered. In the third study, by simulating stand development and dead wood dynamics under various forest management scenarios over a 300-year period, I was able to examine the long-term effects of management on dead wood abundance in the Coastal Province. I estimated potential upper bounds for future dead wood amounts. Dead wood amounts increased over time on average across the Province, mainly because of policies on public lands, especially the federal lands under the Northwest Forest Plan. Forest industry, under the Oregon Forest Practices Act and assuming retention of all snags at harvest and thinning, maintained amounts of dead wood that were similar to present-day levels, but size classes shifted toward the smaller sizes as existing large legacy dead wood decomposed. Non-industrial private lands showed increases from very low present-day amounts of dead wood. Across the Province, legacy logs and snags remained present for over a century of the simulation period, and buffered effects of intensive management to dead wood amounts. Variation across landscapes in starting conditions meant that contrasting management approaches had differential effects on long-term dead wood dynamics depending on where they were applied. Current amounts of dead wood and live vegetation patterns in the Province resulted from historical fire and logging. Results of this simulation study indicate that recently established policies oriented toward dead wood production and retention, in the absence of fire or other large- or mid-scale disturbances, are likely to result in increases in dead wood amounts that greatly exceed present-day levels. My results suggest that dead wood patterns of abundance will continue to diverge according to land ownership and that management practices that foster dead wood creation are of increasing importance to the long-term abundance of large dead wood as legacy dead wood is lost through decomposition. Close

• 384. [Article] Results and review of a riparian survey method used in eastern Oregon

  In the late 1970s, approximately 400 miles of streams were inventoried by the Prineville District of the Bureau of Land Management for in-stream and riparian condition. During the summer of 1994, the riparian ...

  Citation × Citation Citation Abstract Copy Title: Results and review of a riparian survey method used in eastern Oregon Author: Rasmussen, Christine G. In the late 1970s, approximately 400 miles of streams were inventoried by the Prineville District of the Bureau of Land Management for in-stream and riparian condition. During the summer of 1994, the riparian portion of the survey was repeated on 17 of the original streams miles, contained within 11 stream sections where grazing strategies had been altered. This project was a case study designed to evaluate efficiency of the original methods and identify factors involved in individual stream responses. The streams selected to be resurveyed varied in community types present, gradient, elevation, grazing system, disturbance history, influence of beaver, and restoration efforts. Community types were identified by their major components (grass-shrub, sedge-rush) and measured for length and width. Length of stream bank damage was estimated and causes noted. Stream sections were surveyed between matching points for the 1976-78 and 1994 surveys. Most streams had increases in riparian area and decreases in bank damage and lengths of cutbanks, suggesting an upward trend in condition. The bank damage, riparian area, and community identification portions of the survey were identified as useful though composition measurements were determined to be less dependable and repeatable. Title: Results and review of a riparian survey method used in eastern Oregon Author: Rasmussen, Christine G. In the late 1970s, approximately 400 miles of streams were inventoried by the Prineville District of the Bureau of Land Management for in-stream and riparian condition. During the summer of 1994, the riparian portion of the survey was repeated on 17 of the original streams miles, contained within 11 stream sections where grazing strategies had been altered. This project was a case study designed to evaluate efficiency of the original methods and identify factors involved in individual stream responses. The streams selected to be resurveyed varied in community types present, gradient, elevation, grazing system, disturbance history, influence of beaver, and restoration efforts. Community types were identified by their major components (grass-shrub, sedge-rush) and measured for length and width. Length of stream bank damage was estimated and causes noted. Stream sections were surveyed between matching points for the 1976-78 and 1994 surveys. Most streams had increases in riparian area and decreases in bank damage and lengths of cutbanks, suggesting an upward trend in condition. The bank damage, riparian area, and community identification portions of the survey were identified as useful though composition measurements were determined to be less dependable and repeatable. Close

• 385. [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

• 386. [Article] Interactions of cattle and chinook salmon

  Spring chinook salmon spawning occurs in late summer when it is common for cattle to be present in pastures that have streams where fish spawning occurs. This two-year study addressed three main objectives ...

  Citation × Citation Citation Abstract Copy Title: Interactions of cattle and chinook salmon Author: Ballard, Teena M. Spring chinook salmon spawning occurs in late summer when it is common for cattle to be present in pastures that have streams where fish spawning occurs. This two-year study addressed three main objectives relative to behavioral interactions between cattle and spring chinook salmon during the spawning life history stage. These objectives were 1) to determine cattle distribution and behavior within the riparian pasture, 2) to determine if cattle disrupt the spawning behavior of salmon by their presence near the redd and 3) to determine the likelihood of a cow coming into direct contact with a redd. This study did not measure the changes in redd structure or egg survival if contacted by the cattle. The study area was a 41 hectare riparian pasture along an Eastern Oregon stream with cattle stocked at a rate of 0.82 ha/aum and spring chinook salmon spawning at densities of 4.6 redds per kilometer in 1996 and 6.1 redds per kilometer in 1997 in areas accessible to cattle. The pasture contained 2.6 kilometers of stream with approximately 50% of the 2.6 kilometers of stream excluded from cattle since 1978. From mid-August through early-September in each of the two years, cattle and salmon distribution and behavior were recorded every minute for two out of three four-hour periods per day. Cattle preferred the terrestrial habitats by spending 94% of their time in those habitats, approximately 5% in the gravel bar habitats, and <1.0% of their time in direct contact with the aquatic habitat. During the observations of active salmon redds, cattle were visible from the redd location an average of 12% of the time. While visible, cattle spent 96% of the time out of the stream and 84% of the time greater than 3 meters from the redds. There were no encounters of cattle contacting redds during the cattle distribution and behavior observations. However, during the 2 years of observations of the redds, out of 50 cows over the 56 days in the pasture a redd was contacted two different times. This calculates into <0.01% of the time that cattle contacted redds. Spawning activities were not equally distributed, resting in the redd was the dominant activity and spawning was one of the least frequent activities. The majority (83%) of the time spent by salmon spawning, constructing the redd and burying the eggs laid in the redd occurred within the first 2 days of occupying each redd. Salmon continued preexisting patterns of behavior while cattle were within visible range of a redd. When cattle were present, salmon spent 64% of their time resting in the redd and 26% of their time under cover. This pattern of salmon behavior was consistent with spawning season averages where 45% of the time was spent resting in the redd and 30% of the time was spent under cover. The salmon carcasses surveyed in the study area were 100% spawned in both 1996 and 1997 indicating egg loss from retention due to harassment by cattle was not a problem. Cattle were rarely close to a redd so consequently, there was very little opportunity for cattle to interact with salmon or step on redds. Likewise, there was little chance for salmon to change their behavior in response to the presence of cattle. Title: Interactions of cattle and chinook salmon Author: Ballard, Teena M. Spring chinook salmon spawning occurs in late summer when it is common for cattle to be present in pastures that have streams where fish spawning occurs. This two-year study addressed three main objectives relative to behavioral interactions between cattle and spring chinook salmon during the spawning life history stage. These objectives were 1) to determine cattle distribution and behavior within the riparian pasture, 2) to determine if cattle disrupt the spawning behavior of salmon by their presence near the redd and 3) to determine the likelihood of a cow coming into direct contact with a redd. This study did not measure the changes in redd structure or egg survival if contacted by the cattle. The study area was a 41 hectare riparian pasture along an Eastern Oregon stream with cattle stocked at a rate of 0.82 ha/aum and spring chinook salmon spawning at densities of 4.6 redds per kilometer in 1996 and 6.1 redds per kilometer in 1997 in areas accessible to cattle. The pasture contained 2.6 kilometers of stream with approximately 50% of the 2.6 kilometers of stream excluded from cattle since 1978. From mid-August through early-September in each of the two years, cattle and salmon distribution and behavior were recorded every minute for two out of three four-hour periods per day. Cattle preferred the terrestrial habitats by spending 94% of their time in those habitats, approximately 5% in the gravel bar habitats, and <1.0% of their time in direct contact with the aquatic habitat. During the observations of active salmon redds, cattle were visible from the redd location an average of 12% of the time. While visible, cattle spent 96% of the time out of the stream and 84% of the time greater than 3 meters from the redds. There were no encounters of cattle contacting redds during the cattle distribution and behavior observations. However, during the 2 years of observations of the redds, out of 50 cows over the 56 days in the pasture a redd was contacted two different times. This calculates into <0.01% of the time that cattle contacted redds. Spawning activities were not equally distributed, resting in the redd was the dominant activity and spawning was one of the least frequent activities. The majority (83%) of the time spent by salmon spawning, constructing the redd and burying the eggs laid in the redd occurred within the first 2 days of occupying each redd. Salmon continued preexisting patterns of behavior while cattle were within visible range of a redd. When cattle were present, salmon spent 64% of their time resting in the redd and 26% of their time under cover. This pattern of salmon behavior was consistent with spawning season averages where 45% of the time was spent resting in the redd and 30% of the time was spent under cover. The salmon carcasses surveyed in the study area were 100% spawned in both 1996 and 1997 indicating egg loss from retention due to harassment by cattle was not a problem. Cattle were rarely close to a redd so consequently, there was very little opportunity for cattle to interact with salmon or step on redds. Likewise, there was little chance for salmon to change their behavior in response to the presence of cattle. Close

• 387. [Article] Application of stream classification and historical land uses for managed riparian systems of Eastern Oregon

  Twelve stream segments in the Silvies River drainage system were classified in the fall of 1993 and again in 1994, using a morphological classification of natural rivers (Rosgen 1994). Bankfull flow of ...

  Citation × Citation Citation Abstract Copy Title: Application of stream classification and historical land uses for managed riparian systems of Eastern Oregon Author: Zweygardt, Louanne R. Twelve stream segments in the Silvies River drainage system were classified in the fall of 1993 and again in 1994, using a morphological classification of natural rivers (Rosgen 1994). Bankfull flow of stream channels is the key feature of this system. Measurement of bankfull is used in the calculation of entrenchment ratio and width/depth ratio. Analysis of the differences of the averages between years in bankfull measurements showed that despite being consistently repeated at the same locations along the channel, the measurements were found to be different (p=0.000163 for entrenchment ratios and p = 0.0208 for width/depth ratios). Bankfull was found to be a non-repeatable field measure, therefore, a poor benchmark for a classification scheme. Historical information collected for the study area indicated a history of domestic livestock use that dates back as far as the mid-nineteenth century. Although grazed by livestock for several years, settlement of the Bear and Silvies Valleys occurred mostly around the turn of the twentieth century after the stockgrower's homestead acts were passed. Ownership today is dominated by large (relative to the homestead days) ranches. Title: Application of stream classification and historical land uses for managed riparian systems of Eastern Oregon Author: Zweygardt, Louanne R. Twelve stream segments in the Silvies River drainage system were classified in the fall of 1993 and again in 1994, using a morphological classification of natural rivers (Rosgen 1994). Bankfull flow of stream channels is the key feature of this system. Measurement of bankfull is used in the calculation of entrenchment ratio and width/depth ratio. Analysis of the differences of the averages between years in bankfull measurements showed that despite being consistently repeated at the same locations along the channel, the measurements were found to be different (p=0.000163 for entrenchment ratios and p = 0.0208 for width/depth ratios). Bankfull was found to be a non-repeatable field measure, therefore, a poor benchmark for a classification scheme. Historical information collected for the study area indicated a history of domestic livestock use that dates back as far as the mid-nineteenth century. Although grazed by livestock for several years, settlement of the Bear and Silvies Valleys occurred mostly around the turn of the twentieth century after the stockgrower's homestead acts were passed. Ownership today is dominated by large (relative to the homestead days) ranches. Close