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• 31. [Article] Vegetation, Environmental Characteristics, and their Relationships: Variation within the Annually Flooded Riparian Zones of the John Day River Basin, Oregon

  I hypothesized that vegetation and physical environmental characteristics would differ between the upper and lower extents of the annually flooded riparian zone on the John Day River, and that relationships ...

  Citation × Citation Citation Abstract Copy Title: Vegetation, Environmental Characteristics, and their Relationships: Variation within the Annually Flooded Riparian Zones of the John Day River Basin, Oregon Author: Hartsfield, Samuel J. Year: 2009 I hypothesized that vegetation and physical environmental characteristics would differ between the upper and lower extents of the annually flooded riparian zone on the John Day River, and that relationships between species and environmental variables would display differences between these two zones. Vegetation, environmental variables, and relationships between them were assessed for the entire annually flooded riparian zone, and for the proposed upper and lower zones. Data were collected from 60 one-square-meter quadrats: 30 in each the upper and lower zones. Sites were randomly selected and located so that flood duration was roughly equal at all sites within each zone. 34 plant species were encountered: 25 in the upper zone, 27 in the lower zone. Wetland obligate and facultative wetland species groups and eight individual species accounted for statistically different percentages ofquadrat cover between zones. ANOSIM analysis identified two statistically distinct vegetation communities between the two zones. Soil texture averaged 75.85% sand and 20.81% fines. Sand ranged between 36.69% and 95.55%. Fines ranged between 2.54% and 58.84%. A horizon depths and fine soil particle concentrations were greater in the upper zone. Coarser soils with more sand and gravel dominated the lower zone. All enviromnental variables studied, except pH, were highly variable throughout the study area. ANOSIM analysis results suggest that the upper and lower zones have distinct, statistically different physical environments from each other. Regression analyses relating species quadrat cover to physical environmental variables were performed for the total, upper, and lower riparian zones. Numerous differences were identified between the upper and lower riparian zones that the riparian scale analyses did not represent accurately. There were ten instances in which the zone scale analyses identified a relationship in either the upper or lower zone, while the corresponding riparian scale analysis failed to identify any relationship. The results of this study indicate that vegetation and the physical environment are statistically different between the upper and lower zones on this river, and that relationships between a given plant species and environmental variable can vary between zones. Future research and management efforts should consider and address the potential for such between-zone variation. Title: Vegetation, Environmental Characteristics, and their Relationships: Variation within the Annually Flooded Riparian Zones of the John Day River Basin, Oregon Author: Hartsfield, Samuel J. Year: 2009 I hypothesized that vegetation and physical environmental characteristics would differ between the upper and lower extents of the annually flooded riparian zone on the John Day River, and that relationships between species and environmental variables would display differences between these two zones. Vegetation, environmental variables, and relationships between them were assessed for the entire annually flooded riparian zone, and for the proposed upper and lower zones. Data were collected from 60 one-square-meter quadrats: 30 in each the upper and lower zones. Sites were randomly selected and located so that flood duration was roughly equal at all sites within each zone. 34 plant species were encountered: 25 in the upper zone, 27 in the lower zone. Wetland obligate and facultative wetland species groups and eight individual species accounted for statistically different percentages ofquadrat cover between zones. ANOSIM analysis identified two statistically distinct vegetation communities between the two zones. Soil texture averaged 75.85% sand and 20.81% fines. Sand ranged between 36.69% and 95.55%. Fines ranged between 2.54% and 58.84%. A horizon depths and fine soil particle concentrations were greater in the upper zone. Coarser soils with more sand and gravel dominated the lower zone. All enviromnental variables studied, except pH, were highly variable throughout the study area. ANOSIM analysis results suggest that the upper and lower zones have distinct, statistically different physical environments from each other. Regression analyses relating species quadrat cover to physical environmental variables were performed for the total, upper, and lower riparian zones. Numerous differences were identified between the upper and lower riparian zones that the riparian scale analyses did not represent accurately. There were ten instances in which the zone scale analyses identified a relationship in either the upper or lower zone, while the corresponding riparian scale analysis failed to identify any relationship. The results of this study indicate that vegetation and the physical environment are statistically different between the upper and lower zones on this river, and that relationships between a given plant species and environmental variable can vary between zones. Future research and management efforts should consider and address the potential for such between-zone variation. Close

• 32. [Article] Stream-Associated Amphibian Habitat Assessment in the Portland-Vancouver Metropolitan Region

  This study assessed the influence of landscape development on stream-associated amphibians in forested riparian areas within the Portland-Vancouver metropolitan region. Human alteration of landscapes may ...

  Citation × Citation Citation Abstract Copy Title: Stream-Associated Amphibian Habitat Assessment in the Portland-Vancouver Metropolitan Region Author: Dietrich, Andrew Evans Year: 2012 This study assessed the influence of landscape development on stream-associated amphibians in forested riparian areas within the Portland-Vancouver metropolitan region. Human alteration of landscapes may dramatically affect the ecology of neighboring aquatic systems. It was hypothesized that lotic amphibians would be negatively associated with greater amounts of landscape development and positively associated with forested area within the surrounding watershed. Thirty-seven 1st-3rd order streams were sampled between June 21st and September 21st in 2011. Streams potentially providing adequate habitat for stream-obligate amphibians were randomly selected. Amphibians were surveyed along 30-meter stream transects using an active-cover search (ACS). Environmental variables associated with development in surrounding landscapes were measured in situ. GIS delineation was conducted to define landscape-scale variables at stratified distances from riparian networks up-stream of each site via the utilization of the 2006 NLCD dataset and a finer-scale, regional dataset compiled by the Institute for Natural Resources (INR). Amphibians were detected at seventeen of the thirty-seven sampled streams. The most commonly detected species were Dicamptadon tenebrosus, Plethadon vehiculum and Plethadon dunni. Streams where amphibians were observed had lower average water temperature and conductivity, coarser stream substrate and were located on public property more often than streams where no amphibians were detected. Landscape variables were most significant to amphibians within 100 and 200 meters of the upstream stream network. Occupancy of a site by facultative species was best explained by the proportion of mixed forest in the surrounding watershed (R2=0.343, p<0.001). Occupancy of a stream by obligate species was best predicted by measurements of water quality and in-stream cover (Water Temperature: R2=0.275, p<0.001; Water Conductivity: R2=0.248, p<0.001; Cover: R2=0.323, p<0.001). Occupancy of stream refugia by all observed amphibians was positively influenced by higher percentages of forest cover and lower percentages of urban development and herbaceous vegetation in the surrounding watershed. Results of this study indicate that urban refugia must contain adequate riparian forest area, coarse stream substrate and clean, cool water to sustain stream-amphibian communities. Protection of remnant forested headwater stream networks is essential to the conservation of lotic amphibians in this urbanized region. Title: Stream-Associated Amphibian Habitat Assessment in the Portland-Vancouver Metropolitan Region Author: Dietrich, Andrew Evans Year: 2012 This study assessed the influence of landscape development on stream-associated amphibians in forested riparian areas within the Portland-Vancouver metropolitan region. Human alteration of landscapes may dramatically affect the ecology of neighboring aquatic systems. It was hypothesized that lotic amphibians would be negatively associated with greater amounts of landscape development and positively associated with forested area within the surrounding watershed. Thirty-seven 1st-3rd order streams were sampled between June 21st and September 21st in 2011. Streams potentially providing adequate habitat for stream-obligate amphibians were randomly selected. Amphibians were surveyed along 30-meter stream transects using an active-cover search (ACS). Environmental variables associated with development in surrounding landscapes were measured in situ. GIS delineation was conducted to define landscape-scale variables at stratified distances from riparian networks up-stream of each site via the utilization of the 2006 NLCD dataset and a finer-scale, regional dataset compiled by the Institute for Natural Resources (INR). Amphibians were detected at seventeen of the thirty-seven sampled streams. The most commonly detected species were Dicamptadon tenebrosus, Plethadon vehiculum and Plethadon dunni. Streams where amphibians were observed had lower average water temperature and conductivity, coarser stream substrate and were located on public property more often than streams where no amphibians were detected. Landscape variables were most significant to amphibians within 100 and 200 meters of the upstream stream network. Occupancy of a site by facultative species was best explained by the proportion of mixed forest in the surrounding watershed (R2=0.343, p<0.001). Occupancy of a stream by obligate species was best predicted by measurements of water quality and in-stream cover (Water Temperature: R2=0.275, p<0.001; Water Conductivity: R2=0.248, p<0.001; Cover: R2=0.323, p<0.001). Occupancy of stream refugia by all observed amphibians was positively influenced by higher percentages of forest cover and lower percentages of urban development and herbaceous vegetation in the surrounding watershed. Results of this study indicate that urban refugia must contain adequate riparian forest area, coarse stream substrate and clean, cool water to sustain stream-amphibian communities. Protection of remnant forested headwater stream networks is essential to the conservation of lotic amphibians in this urbanized region. Close

• 33. [Article] Cascades Island Lamprey Passage Structure: Evaluating Passage and Migration Following Structure Modifications

  Pacific lamprey (Entosphenus tridentatus), an endemic species to the Columbia River Basin, U.S.A, has experienced staggering decreases in returns to spawning territories in recent decades. As lamprey are ...

  Citation × Citation Citation Abstract Copy Title: Cascades Island Lamprey Passage Structure: Evaluating Passage and Migration Following Structure Modifications Author: Lopez-Johnston, Siena Marie Year: 2014 Pacific lamprey (Entosphenus tridentatus), an endemic species to the Columbia River Basin, U.S.A, has experienced staggering decreases in returns to spawning territories in recent decades. As lamprey are threatened severely by a lack of passage at mainstem dams, lamprey specific passage structures have been designed and constructed to address the problem. The Cascades Island Lamprey Passage Structure (LPS) at Bonneville Dam is the longest and steepest structure of its type, following the addition of an exit pipe which allows lampreys to travel from the tailrace of the dam to the forebay. The intent of this study was to assess lamprey use of the structure and whether the structure hinders lamprey migration to subsequent dams. The study was carried out during the 2013 migration season. The study used three different treatment groups of lampreys released on five dates spanning the migration season (n=75 lamprey). Two of these groups (n=50), with different tagging methods, were released directly into the LPS to assess passage success, travel time, and tagging effect. The third group (n=25) was released into the forebay to test whether the structure impedes migration upstream. Fish were monitored via receiver arrays on the LPS and at dams on the river system. Overall passage efficiency was 74% (37 of 50 used the CI LPS successfully). Mean travel time to navigate the structure was 12 h. Fish size had no significant effect on travel time in the LPS. Water temperature had a significant effect on travel time in the LPS. There was no statistically significant effect of tagging on passage efficiency or travel time. The groups that used the LPS performed slightly better migrating upstream to the next dam than the group that bypassed the structure, but the difference was not significant. The groups that used the LPS traveled to more subsequent dams upstream than did the group that bypassed the LPS. It can be concluded that lamprey passed the structure successfully. Temperature (proxy for seasonality) had an effect on travel time in the LPS; however fish size and tagging had no effect. The LPS does not affect the ability of migrating lampreys to continue migration to subsequent dams. Such findings have important implications for management of lamprey in the region. Title: Cascades Island Lamprey Passage Structure: Evaluating Passage and Migration Following Structure Modifications Author: Lopez-Johnston, Siena Marie Year: 2014 Pacific lamprey (Entosphenus tridentatus), an endemic species to the Columbia River Basin, U.S.A, has experienced staggering decreases in returns to spawning territories in recent decades. As lamprey are threatened severely by a lack of passage at mainstem dams, lamprey specific passage structures have been designed and constructed to address the problem. The Cascades Island Lamprey Passage Structure (LPS) at Bonneville Dam is the longest and steepest structure of its type, following the addition of an exit pipe which allows lampreys to travel from the tailrace of the dam to the forebay. The intent of this study was to assess lamprey use of the structure and whether the structure hinders lamprey migration to subsequent dams. The study was carried out during the 2013 migration season. The study used three different treatment groups of lampreys released on five dates spanning the migration season (n=75 lamprey). Two of these groups (n=50), with different tagging methods, were released directly into the LPS to assess passage success, travel time, and tagging effect. The third group (n=25) was released into the forebay to test whether the structure impedes migration upstream. Fish were monitored via receiver arrays on the LPS and at dams on the river system. Overall passage efficiency was 74% (37 of 50 used the CI LPS successfully). Mean travel time to navigate the structure was 12 h. Fish size had no significant effect on travel time in the LPS. Water temperature had a significant effect on travel time in the LPS. There was no statistically significant effect of tagging on passage efficiency or travel time. The groups that used the LPS performed slightly better migrating upstream to the next dam than the group that bypassed the structure, but the difference was not significant. The groups that used the LPS traveled to more subsequent dams upstream than did the group that bypassed the LPS. It can be concluded that lamprey passed the structure successfully. Temperature (proxy for seasonality) had an effect on travel time in the LPS; however fish size and tagging had no effect. The LPS does not affect the ability of migrating lampreys to continue migration to subsequent dams. Such findings have important implications for management of lamprey in the region. Close

• 34. [Article] Siltcoos Lake Nonpoint Source Implementation Grant: Water Quality Conditions and Nutrient Sources

  Siltcoos Lake is a large (1280 hectares), shallow (mean depth 3.3 m; maximum depth 6.7 m) lake located on the Central Oregon Coast, just south of Florence and bordered by Dunes City, Oregon. The outflow ...

  Citation × Citation Citation Abstract Copy Title: Siltcoos Lake Nonpoint Source Implementation Grant: Water Quality Conditions and Nutrient Sources Author: Sytsma, Mark D., Miller, Rich Year: 2010 Siltcoos Lake is a large (1280 hectares), shallow (mean depth 3.3 m; maximum depth 6.7 m) lake located on the Central Oregon Coast, just south of Florence and bordered by Dunes City, Oregon. The outflow and water level of Siltcoos Lake is regulated by a dam on the Siltcoos River 4 km upstream from the Pacific. Several permanent streams feed the lake from its 176 square kilometer watershed including Fiddle Creek, Maple Creek, and Woahink Creek, the outflow from Woahink Lake. Much of the watershed is forested and used for timber harvest, residential development, and limited agricultural production. The lake is popular for recreational activities, particularly fishing for wild coastal Coho salmon, rainbow trout, cutthroat trout, largemouth bass, bluegill, crappie, and yellow perch (Buckman 2004). The lake is also the domestic drinking water source for approximately 125 of the 1330 residents of Dunes City and numerous residents outside the city limits within Lane and Douglas Counties (LCOG 2002). During the fall of 2007 a dense bloom of the potentially toxigenic blue-green algal species Anabaena planktonica prompted Dunes City, the South Coast Water District, the Lane County Health Department, and the Oregon Department of Human Services to issue an advisory against usage of Siltcoos Lake water for drinking and other domestic use (DHS 2007). Residents dependent upon Siltcoos Lake were forced to find alternate domestic water sources for a total of 52 days. This incident was part of a long history of water quality problems including dense algal growth and excessive growth of the non-native aquatic macrophytes Brazilian elodea (Egeria densa), parrotsfeather (Myriophyllum aquaticum), and two-leaf water milfoil (Myriophyllum heterophyllum) (Pfauth and Sytsma 2005; Johnson et al. 1985; McHugh 1979). Because of the water quality problems, the Oregon Department of Environmental Quality (DEQ) placed the lake the 303(d) list of impaired water bodies; specifically due to violations of the “aquatic weeds and algae” water quality criterion (DEQ 1998; DEQ 2006). Dunes City has acted on water quality concerns for both Siltcoos and Woahink Lakes by issuing a temporary building moratorium (Dunes City 2006a), a septic tank maintenance ordinance (Dunes City 2006b), and an ordinance limiting phosphorus use (Dunes City 2007). Preliminary assessments (Johnson, et al. 1985, LCOG 2002) indicate multiple sources of water quality problems including excess nutrient and/or sediment loading from residential development, poorly functioning on-site septic systems, private forestry and agricultural practices and introductions of non-native aquatic plant species. This report summarizes data collected by Portland State University and project partners between June 2008 and May 2009 to better define water quality conditions within the lake as well as potential nutrient sources. Physical, chemical, and biological data were collected at lake and tributary sites over the one year period. Data were evaluated across sites, depth and the season. The information collected will contribute to total maximum daily load (TMDL) development for the Midcoast Lakes and can be used to identify and prioritize restoration activities in the Siltcoos Lake watershed. Title: Siltcoos Lake Nonpoint Source Implementation Grant: Water Quality Conditions and Nutrient Sources Author: Sytsma, Mark D., Miller, Rich Year: 2010 Siltcoos Lake is a large (1280 hectares), shallow (mean depth 3.3 m; maximum depth 6.7 m) lake located on the Central Oregon Coast, just south of Florence and bordered by Dunes City, Oregon. The outflow and water level of Siltcoos Lake is regulated by a dam on the Siltcoos River 4 km upstream from the Pacific. Several permanent streams feed the lake from its 176 square kilometer watershed including Fiddle Creek, Maple Creek, and Woahink Creek, the outflow from Woahink Lake. Much of the watershed is forested and used for timber harvest, residential development, and limited agricultural production. The lake is popular for recreational activities, particularly fishing for wild coastal Coho salmon, rainbow trout, cutthroat trout, largemouth bass, bluegill, crappie, and yellow perch (Buckman 2004). The lake is also the domestic drinking water source for approximately 125 of the 1330 residents of Dunes City and numerous residents outside the city limits within Lane and Douglas Counties (LCOG 2002). During the fall of 2007 a dense bloom of the potentially toxigenic blue-green algal species Anabaena planktonica prompted Dunes City, the South Coast Water District, the Lane County Health Department, and the Oregon Department of Human Services to issue an advisory against usage of Siltcoos Lake water for drinking and other domestic use (DHS 2007). Residents dependent upon Siltcoos Lake were forced to find alternate domestic water sources for a total of 52 days. This incident was part of a long history of water quality problems including dense algal growth and excessive growth of the non-native aquatic macrophytes Brazilian elodea (Egeria densa), parrotsfeather (Myriophyllum aquaticum), and two-leaf water milfoil (Myriophyllum heterophyllum) (Pfauth and Sytsma 2005; Johnson et al. 1985; McHugh 1979). Because of the water quality problems, the Oregon Department of Environmental Quality (DEQ) placed the lake the 303(d) list of impaired water bodies; specifically due to violations of the “aquatic weeds and algae” water quality criterion (DEQ 1998; DEQ 2006). Dunes City has acted on water quality concerns for both Siltcoos and Woahink Lakes by issuing a temporary building moratorium (Dunes City 2006a), a septic tank maintenance ordinance (Dunes City 2006b), and an ordinance limiting phosphorus use (Dunes City 2007). Preliminary assessments (Johnson, et al. 1985, LCOG 2002) indicate multiple sources of water quality problems including excess nutrient and/or sediment loading from residential development, poorly functioning on-site septic systems, private forestry and agricultural practices and introductions of non-native aquatic plant species. This report summarizes data collected by Portland State University and project partners between June 2008 and May 2009 to better define water quality conditions within the lake as well as potential nutrient sources. Physical, chemical, and biological data were collected at lake and tributary sites over the one year period. Data were evaluated across sites, depth and the season. The information collected will contribute to total maximum daily load (TMDL) development for the Midcoast Lakes and can be used to identify and prioritize restoration activities in the Siltcoos Lake watershed. Close

• 35. [Article] Effects of Spatially Distributed Stream Power on Check Dam Function in Small Upland Watersheds: A Case Study of the Upper Laja Watershed, Guanajuato, Mexico

  Watershed restoration comes in a variety of forms depending on which set of problems are sought to be remedied. Severe soil erosion, in the form of gullying and/or headcutting, can be mitigated through ...

  Citation × Citation Citation Abstract Copy Title: Effects of Spatially Distributed Stream Power on Check Dam Function in Small Upland Watersheds: A Case Study of the Upper Laja Watershed, Guanajuato, Mexico Author: Herzfeld, Zachary Andrew Year: 2017 Watershed restoration comes in a variety of forms depending on which set of problems are sought to be remedied. Severe soil erosion, in the form of gullying and/or headcutting, can be mitigated through constructing check dams in well-selected locations. This practice has been used throughout the upland subwatersheds within the Upper Laja River watershed in Guanajuato, Mexico. The present study employed Wolman pebble counts to systematically assess the effectiveness of 21 check dams located near the city of San Miguel de Allende. Particle size distributions taken directly downstream and upstream of each check dam were differentiated, aggregated and compared--with the difference between median particle size of downstream and upstream distributions defined as DsD50-UsD50. Several subwatershed attributes were calculated in a GIS for comparison to DsD50-UsD50 values. Results indicate that, on aggregate, the check dams studied were moderately successful at retaining sediment that becomes entrained in concentrated flow (DsD50-UsD50 = 15.4 mm; p < 0.001). Individually, 18 of the 21 check dams surveyed had statistically significant differences between DsD50 and UsD50 (p < 0.05). The subwatershed variables of local channel slope (r = 0.55), mean subwatershed slope (r = 0.46), subwatershed area (r = 0.59), distance from channel head (r = 0.54), percent canopy cover (r = 0.46), Qmed (r = 0.46), total stream power (r = 0.58), and change in total stream power (r = -0.45) were found to be statistically significant when correlated with DsD50-UsD50 values (p < 0.05). Change in total stream power was used to classify stream reaches as either erosion or deposition-dominated. When compared, the DsD50-UsD50 values from check dams located in erosion and deposition-dominated reaches are statistically different (p < 0.05); higher performing check dams were predominantly found in deposition-dominated reaches. The results of this study suggest that spatially distributed stream power can be used as a variable for making decisions about future check dam locations. In particular, check dams are more likely to be effective if they are located within deposition-dominated areas (negative change in total stream power) and in areas of decreasing change in total stream power. In general, this study's findings also support locating check dams in second order streams. Title: Effects of Spatially Distributed Stream Power on Check Dam Function in Small Upland Watersheds: A Case Study of the Upper Laja Watershed, Guanajuato, Mexico Author: Herzfeld, Zachary Andrew Year: 2017 Watershed restoration comes in a variety of forms depending on which set of problems are sought to be remedied. Severe soil erosion, in the form of gullying and/or headcutting, can be mitigated through constructing check dams in well-selected locations. This practice has been used throughout the upland subwatersheds within the Upper Laja River watershed in Guanajuato, Mexico. The present study employed Wolman pebble counts to systematically assess the effectiveness of 21 check dams located near the city of San Miguel de Allende. Particle size distributions taken directly downstream and upstream of each check dam were differentiated, aggregated and compared--with the difference between median particle size of downstream and upstream distributions defined as DsD50-UsD50. Several subwatershed attributes were calculated in a GIS for comparison to DsD50-UsD50 values. Results indicate that, on aggregate, the check dams studied were moderately successful at retaining sediment that becomes entrained in concentrated flow (DsD50-UsD50 = 15.4 mm; p < 0.001). Individually, 18 of the 21 check dams surveyed had statistically significant differences between DsD50 and UsD50 (p < 0.05). The subwatershed variables of local channel slope (r = 0.55), mean subwatershed slope (r = 0.46), subwatershed area (r = 0.59), distance from channel head (r = 0.54), percent canopy cover (r = 0.46), Qmed (r = 0.46), total stream power (r = 0.58), and change in total stream power (r = -0.45) were found to be statistically significant when correlated with DsD50-UsD50 values (p < 0.05). Change in total stream power was used to classify stream reaches as either erosion or deposition-dominated. When compared, the DsD50-UsD50 values from check dams located in erosion and deposition-dominated reaches are statistically different (p < 0.05); higher performing check dams were predominantly found in deposition-dominated reaches. The results of this study suggest that spatially distributed stream power can be used as a variable for making decisions about future check dam locations. In particular, check dams are more likely to be effective if they are located within deposition-dominated areas (negative change in total stream power) and in areas of decreasing change in total stream power. In general, this study's findings also support locating check dams in second order streams. Close

• 36. [Article] Impacts of Climate Change and Urban Development on Water Resources in the Tualatin River Basin

  Potential impacts of climate change on the water resources of the Pacific Northwest of the United States include earlier peak runoff, reduced summer flows, and increased winter flooding. An increase in ...

  Citation × Citation Citation Abstract Copy Title: Impacts of Climate Change and Urban Development on Water Resources in the Tualatin River Basin Author: Praskievicz, Sarah Year: 2009 Potential impacts of climate change on the water resources of the Pacific Northwest of the United States include earlier peak runoff, reduced summer flows, and increased winter flooding. An increase in impervious surfaces, accompanied by urban development, is known to decrease infiltration and increase surface runoff. Alterations of flow amount and pathways can alter water quality through dilution or flushing effects. I used the United States Environmental Protection Agency's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) modeling system to investigate the relative importance of future climate change and land use change in determining the quantity and quality of freshwater resources in north western Oregon's Tualatin River Basin. The basin was chosen for this study because it is rapidly urbanizing and representative of other low-elevation basins in the region. BASINS models were calibrated and validated using historic flow and water quality data from 1991 to 2006. The goodness-of-fit for the calibrated hydrology, suspended sediment, and orthophosphate models was high, with coefficients of determination ranging from 0.72 to 0.93 in the calibration period. The calibrated models were run under a range of eight downscaled climate change, two regional land use change, and four combined scenarios. Results included average increases in winter flows of ten percent, decreases in summer flows of thirty-seven percent, and increases in fifth percentile flows of up to eighty percent as a result of climate change in the Tualatin River Basin. For land use change, the results included an increase in annual flows of twenty-one percent for the development-oriented scenario and a decrease of sixteen percent for the conservation-oriented scenario, with amplified changes at the sub-basin scale, including more than doubled winter flow. For combined scenarios of climate change and urban development, there is a projected increase in winter flows of up to seventy-one percent and decrease in summer flows of up to forty-eight percent. Changes in suspended sediment and orthophosphate loading broadly tracked hydrological changes, with winter increases and summer decreases. The results are relevant to regional planners interested in the long-term response of water resources to climate change and land use change at the basin scale. Title: Impacts of Climate Change and Urban Development on Water Resources in the Tualatin River Basin Author: Praskievicz, Sarah Year: 2009 Potential impacts of climate change on the water resources of the Pacific Northwest of the United States include earlier peak runoff, reduced summer flows, and increased winter flooding. An increase in impervious surfaces, accompanied by urban development, is known to decrease infiltration and increase surface runoff. Alterations of flow amount and pathways can alter water quality through dilution or flushing effects. I used the United States Environmental Protection Agency's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) modeling system to investigate the relative importance of future climate change and land use change in determining the quantity and quality of freshwater resources in north western Oregon's Tualatin River Basin. The basin was chosen for this study because it is rapidly urbanizing and representative of other low-elevation basins in the region. BASINS models were calibrated and validated using historic flow and water quality data from 1991 to 2006. The goodness-of-fit for the calibrated hydrology, suspended sediment, and orthophosphate models was high, with coefficients of determination ranging from 0.72 to 0.93 in the calibration period. The calibrated models were run under a range of eight downscaled climate change, two regional land use change, and four combined scenarios. Results included average increases in winter flows of ten percent, decreases in summer flows of thirty-seven percent, and increases in fifth percentile flows of up to eighty percent as a result of climate change in the Tualatin River Basin. For land use change, the results included an increase in annual flows of twenty-one percent for the development-oriented scenario and a decrease of sixteen percent for the conservation-oriented scenario, with amplified changes at the sub-basin scale, including more than doubled winter flow. For combined scenarios of climate change and urban development, there is a projected increase in winter flows of up to seventy-one percent and decrease in summer flows of up to forty-eight percent. Changes in suspended sediment and orthophosphate loading broadly tracked hydrological changes, with winter increases and summer decreases. The results are relevant to regional planners interested in the long-term response of water resources to climate change and land use change at the basin scale. Close

• 37. [Article] Continuous Deflection Separation of Stormwater Particulates

  Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory ...

  Citation × Citation Citation Abstract Copy Title: Continuous Deflection Separation of Stormwater Particulates Author: Schwarz, Tracy S., Wells, Scott A. Year: 1999 Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory investigation into particle removal efficiency of a prototype Continuous Deflective Separation (CDS) device was made in the laboratory. Particle size distributions were obtained for roadway drainage surfaces. These distributions were used to assess the predicted performance of a CDS unit in the field. Flow rates in the laboratory tests ranged from 125 GPM (7.9 l/s) to 270 GPM (17.0 l/s). Screen sizes used for testing were 1200 m and 2400 m. Using four different sand types and the two screen sizes, particle capture rates were determined for the CDS unit. Internal velocities were measured at seventy-two measuring positions within the main chamber of the CDS unit. At 270 GPM capture rates based on particle size ranged from 12% to 100% with the 2400 m screen, and 22% to 100% with the 1200 m screen. Cumulative mass capture rates were 73% and 70% for the 1200 m and 2400 m screens, respectively, at 270 gpm and 84% at 125 gpm for the given particle distribution used. Title: Continuous Deflection Separation of Stormwater Particulates Author: Schwarz, Tracy S., Wells, Scott A. Year: 1999 Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory investigation into particle removal efficiency of a prototype Continuous Deflective Separation (CDS) device was made in the laboratory. Particle size distributions were obtained for roadway drainage surfaces. These distributions were used to assess the predicted performance of a CDS unit in the field. Flow rates in the laboratory tests ranged from 125 GPM (7.9 l/s) to 270 GPM (17.0 l/s). Screen sizes used for testing were 1200 m and 2400 m. Using four different sand types and the two screen sizes, particle capture rates were determined for the CDS unit. Internal velocities were measured at seventy-two measuring positions within the main chamber of the CDS unit. At 270 GPM capture rates based on particle size ranged from 12% to 100% with the 2400 m screen, and 22% to 100% with the 1200 m screen. Cumulative mass capture rates were 73% and 70% for the 1200 m and 2400 m screens, respectively, at 270 gpm and 84% at 125 gpm for the given particle distribution used. Close

• 38. [Article] Assessment of the Hydrologic Response to Climate Change in the Upper Deschutes River Basin, Central Oregon

  Effects of climate change in the Cascade Range will likely include more rain, less snow, and earlier snowmelt in the Cascade Range as compared to present conditions. These changes, in turn, will affect ...

  Citation × Citation Citation Abstract Copy Title: Assessment of the Hydrologic Response to Climate Change in the Upper Deschutes River Basin, Central Oregon Author: Chang, Heejun, Waibel, M. Scott, Gannett, Marshall W., Hulbe, Christina L. Year: 2011 Effects of climate change in the Cascade Range will likely include more rain, less snow, and earlier snowmelt in the Cascade Range as compared to present conditions. These changes, in turn, will affect the timing of runoff, groundwater recharge, and groundwater discharge to spring-fed streams. This hydrologic response needs to be examined and understood due to implications for water management. In this study, a water- and energy-balance model was used to explore 21st century changes in the water budget in the upper Deschutes Basin, and a groundwater model was used to evaluate the response of the groundwater system to those changes. A Deep Percolation Model (DPM) developed for the basin in the 1990s uses spatially distributed climate data to calculate a daily mass balance for the major components of the hydrologic budget. For this work, we drove the DPM using ensemble means of eight downscaled global climate models with the Intergovernmental Panel on Climate Change?s A1B and B1 emission scenarios. Although similar for both scenarios, greater changes in the timing of runoff and recharge as well as higher reductions in snowpack occur using the A1B scenario. Considering both scenarios, diminished snowpack results in reductions in spring runoff ranging from 40% to 63% and recharge from 21% to 37%. These reductions are offset by late fall and winter increases. Also, spatial changes in the mean annual ratio of recharge to runoff occur due to changes in soil infiltration rates. The modeled response of the groundwater system to changes in the time and amount of recharge varies spatially. Short flow-path systems in the upper part of the basin are most sensitive to change in seasonality of recharge. At regional scales, diffusion along groundwater flow paths partially attenuates the effects of changes in recharge timing. Furthermore, slight increases in total annual groundwater discharge to smaller streams in the upper portion of the basin, and slight decreases in discharge to larger stream systems in the north-central portion of the basin are projected. Title: Assessment of the Hydrologic Response to Climate Change in the Upper Deschutes River Basin, Central Oregon Author: Chang, Heejun, Waibel, M. Scott, Gannett, Marshall W., Hulbe, Christina L. Year: 2011 Effects of climate change in the Cascade Range will likely include more rain, less snow, and earlier snowmelt in the Cascade Range as compared to present conditions. These changes, in turn, will affect the timing of runoff, groundwater recharge, and groundwater discharge to spring-fed streams. This hydrologic response needs to be examined and understood due to implications for water management. In this study, a water- and energy-balance model was used to explore 21st century changes in the water budget in the upper Deschutes Basin, and a groundwater model was used to evaluate the response of the groundwater system to those changes. A Deep Percolation Model (DPM) developed for the basin in the 1990s uses spatially distributed climate data to calculate a daily mass balance for the major components of the hydrologic budget. For this work, we drove the DPM using ensemble means of eight downscaled global climate models with the Intergovernmental Panel on Climate Change?s A1B and B1 emission scenarios. Although similar for both scenarios, greater changes in the timing of runoff and recharge as well as higher reductions in snowpack occur using the A1B scenario. Considering both scenarios, diminished snowpack results in reductions in spring runoff ranging from 40% to 63% and recharge from 21% to 37%. These reductions are offset by late fall and winter increases. Also, spatial changes in the mean annual ratio of recharge to runoff occur due to changes in soil infiltration rates. The modeled response of the groundwater system to changes in the time and amount of recharge varies spatially. Short flow-path systems in the upper part of the basin are most sensitive to change in seasonality of recharge. At regional scales, diffusion along groundwater flow paths partially attenuates the effects of changes in recharge timing. Furthermore, slight increases in total annual groundwater discharge to smaller streams in the upper portion of the basin, and slight decreases in discharge to larger stream systems in the north-central portion of the basin are projected. Close

• 39. [Article] Searching for Biogeochemical Hot Spots in Three Dimensions: Soil C and N Cycling in Hydropedologic Settings in a Northern Hardwood Forest

  Understanding and predicting the extent, location, and function of biogeochemical hot spots at the watershed scale is a frontier in environmental science. We applied a hydropedologic approach to identify ...

  Citation × Citation Citation Abstract Copy Title: Searching for Biogeochemical Hot Spots in Three Dimensions: Soil C and N Cycling in Hydropedologic Settings in a Northern Hardwood Forest Author: Morse, Jennifer L., Werner, S F., Gillin, Cody P., Goodale, Christine L., Bailey, Scott W., McGuire, Kevin J., Groffman, Peter M. Year: 2014 Understanding and predicting the extent, location, and function of biogeochemical hot spots at the watershed scale is a frontier in environmental science. We applied a hydropedologic approach to identify (1) biogeochemical differences among morphologically distinct hydropedologic settings and (2) hot spots of microbial carbon (C) and nitrogen (N) cycling activity in a northern hardwood forest in Hubbard Brook Experimental Forest, New Hampshire, USA. We assessed variables related to C and N cycling in spodic hydropedologic settings (typical podzols, bimodal podzols, and Bh podzols) and groundwater seeps during August 2010. We found that soil horizons (Oi/Oe, Oa/A, and B) differed significantly for most variables. B horizons (>10 cm) accounted for 71% (±11%) of C pools and 62% (±10%) of microbial biomass C in the sampled soil profile, whereas the surface horizons (Oi/Oe and Oa/A; 0–10 cm) were dominant zones for N-cycle-related variables. Watershed-wide estimates of C and N cycling were higher by 34 to 43% (±17–19%) when rates, horizon thickness, and areal extent of each hydropedologic setting were incorporated, versus conventionally calculated estimates for typical podzols that included only the top 10 cm of mineral soil. Despite the variation in profile development in typical, bimodal, and Bh podzols, we did not detect significant differences in C and N cycling among them. Across all soil horizons and hydropedologic settings, we found strong links between biogeochemical cycling and soil C, suggesting that the accumulation of C in soils may be a robust indicator of microbial C and N cycling capacity in the landscape. Title: Searching for Biogeochemical Hot Spots in Three Dimensions: Soil C and N Cycling in Hydropedologic Settings in a Northern Hardwood Forest Author: Morse, Jennifer L., Werner, S F., Gillin, Cody P., Goodale, Christine L., Bailey, Scott W., McGuire, Kevin J., Groffman, Peter M. Year: 2014 Understanding and predicting the extent, location, and function of biogeochemical hot spots at the watershed scale is a frontier in environmental science. We applied a hydropedologic approach to identify (1) biogeochemical differences among morphologically distinct hydropedologic settings and (2) hot spots of microbial carbon (C) and nitrogen (N) cycling activity in a northern hardwood forest in Hubbard Brook Experimental Forest, New Hampshire, USA. We assessed variables related to C and N cycling in spodic hydropedologic settings (typical podzols, bimodal podzols, and Bh podzols) and groundwater seeps during August 2010. We found that soil horizons (Oi/Oe, Oa/A, and B) differed significantly for most variables. B horizons (>10 cm) accounted for 71% (±11%) of C pools and 62% (±10%) of microbial biomass C in the sampled soil profile, whereas the surface horizons (Oi/Oe and Oa/A; 0–10 cm) were dominant zones for N-cycle-related variables. Watershed-wide estimates of C and N cycling were higher by 34 to 43% (±17–19%) when rates, horizon thickness, and areal extent of each hydropedologic setting were incorporated, versus conventionally calculated estimates for typical podzols that included only the top 10 cm of mineral soil. Despite the variation in profile development in typical, bimodal, and Bh podzols, we did not detect significant differences in C and N cycling among them. Across all soil horizons and hydropedologic settings, we found strong links between biogeochemical cycling and soil C, suggesting that the accumulation of C in soils may be a robust indicator of microbial C and N cycling capacity in the landscape. Close

• 40. [Article] Fish Species Introductions Provide Novel Insights into the Patterns and Drivers of Phylogenetic Structure in Freshwaters

  Despite long-standing interest of terrestrial ecologists, freshwater ecosystems are a fertile, yet unappreciated, testing ground for applying community phylogenetics to uncover mechanisms of species assembly. ...

  Citation × Citation Citation Abstract Copy Title: Fish Species Introductions Provide Novel Insights into the Patterns and Drivers of Phylogenetic Structure in Freshwaters Author: Strecker, Angela L., Olden, Julian D. Year: 2014 Despite long-standing interest of terrestrial ecologists, freshwater ecosystems are a fertile, yet unappreciated, testing ground for applying community phylogenetics to uncover mechanisms of species assembly. We quantify phylogenetic clustering and overdispersion of native and non-native fishes of a large river basin in the American Southwest to test for the mechanisms (environmental filtering versus competitive exclusion) and spatial scales influencing community structure. Contrary to expectations, non-native species were phylogenetically clustered and related to natural environmental conditions, whereas native species were not phylogenetically structured, likely reflecting human-related changes to the basin. The species that are most invasive (in terms of ecological impacts) tended to be the most phylogenetically divergent from natives across watersheds, but not within watersheds, supporting the hypothesis that Darwin's naturalization conundrum is driven by the spatial scale. Phylogenetic distinctiveness may facilitate non-native establishment at regional scales, but environmental filtering restricts local membership to closely related species with physiological tolerances for current environments. By contrast, native species may have been phylogenetically clustered in historical times, but species loss from contemporary populations by anthropogenic activities has likely shaped the phylogenetic signal. Our study implies that fundamental mechanisms of community assembly have changed, with fundamental consequences for the biogeography of both native and non-native species. Title: Fish Species Introductions Provide Novel Insights into the Patterns and Drivers of Phylogenetic Structure in Freshwaters Author: Strecker, Angela L., Olden, Julian D. Year: 2014 Despite long-standing interest of terrestrial ecologists, freshwater ecosystems are a fertile, yet unappreciated, testing ground for applying community phylogenetics to uncover mechanisms of species assembly. We quantify phylogenetic clustering and overdispersion of native and non-native fishes of a large river basin in the American Southwest to test for the mechanisms (environmental filtering versus competitive exclusion) and spatial scales influencing community structure. Contrary to expectations, non-native species were phylogenetically clustered and related to natural environmental conditions, whereas native species were not phylogenetically structured, likely reflecting human-related changes to the basin. The species that are most invasive (in terms of ecological impacts) tended to be the most phylogenetically divergent from natives across watersheds, but not within watersheds, supporting the hypothesis that Darwin's naturalization conundrum is driven by the spatial scale. Phylogenetic distinctiveness may facilitate non-native establishment at regional scales, but environmental filtering restricts local membership to closely related species with physiological tolerances for current environments. By contrast, native species may have been phylogenetically clustered in historical times, but species loss from contemporary populations by anthropogenic activities has likely shaped the phylogenetic signal. Our study implies that fundamental mechanisms of community assembly have changed, with fundamental consequences for the biogeography of both native and non-native species. Close