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• 2781. [Article] Homeowner Association Resident’s Perceptions on Stormwater Retention Ponds and Clean Drinking Water: (Montgomery West Homeowners Association (MWHOA) Gaithersburg, Maryland).

  Graduation date: 2015

  Citation × Citation Citation Abstract Copy Title: Homeowner Association Resident’s Perceptions on Stormwater Retention Ponds and Clean Drinking Water: (Montgomery West Homeowners Association (MWHOA) Gaithersburg, Maryland). Author: Roberts, William Hadyn Jr Graduation date: 2015 Title: Homeowner Association Resident’s Perceptions on Stormwater Retention Ponds and Clean Drinking Water: (Montgomery West Homeowners Association (MWHOA) Gaithersburg, Maryland). Author: Roberts, William Hadyn Jr Graduation date: 2015 Close

• 2782. [Article] Ecology of woody riparian vegetation in tributaries of the Upper Grande Ronde River basin, Oregon

  Two studies on Catherine Creek and Meadow Creek of the Upper Grande Ronde River basin, quantified several physical and biotic influences on woody riparian community composition and structure. The Catherine ...

  Citation × Citation Citation Abstract Copy Title: Ecology of woody riparian vegetation in tributaries of the Upper Grande Ronde River basin, Oregon Author: Lytjen, Danna J. Two studies on Catherine Creek and Meadow Creek of the Upper Grande Ronde River basin, quantified several physical and biotic influences on woody riparian community composition and structure. The Catherine Creek study examined the association of woody riparian species with elevational and geomorphic gradients. The Meadow Creek study examined the influence of mammal herbivory on composition and abundance of woody riparian species. At Catherine Creek, twenty nine plots were established at 50 m intervals of elevation from near the stream origin at 2207 m in the Wallowa Mountains to the foothills of the Grande Ronde Valley at 988 m. Woody plant community composition was associated with the dominant environmental variable, elevation. Distribution of dominant riparian species was strongly associated with fluvial surfaces. Black cottonwood (Populus balsamifera) was associated with gravel and cobble bars proximal to the stream channel, and along with ponderosa pine (Pinus ponderosa) was also associated with elevated boulder bars. Alders (A. incana and A. viridis) and willows (Salix bebbiana, S. boothii, S. exigua, S. lucida, S. melanopsis, S. prolixa, and S. sitchensis) were associated with annual floodplains. At Meadow Creek, grazing by cattle was ended in 1991 on the entire study reach and three deer and elk exclosures were built within the reach adjacent to the creek. Inside deer/elk exclosures from 1991 to 1995, mean heights of tagged cottonwoods, willows, and alders increased by 86% to 180%. Outside exclosures, mean heights of cottonwoods and alders increased 109% and 99% respectively, but willows showed little change in height. Both inside and outside of exclosures mean crown volume of cottonwoods increased over 1000% and mean crown volume of alders increased over 600%. Willow volume inside exclosures increased 376% in root sprouting (clonal) species and 528% in crown sprouting (non-clonal) species, while outside of exclosures volume increased 79% and 144% respectively. On both sides of exclosure fences, beaver herbivory had a significant effect on cottonwood height growth in 1994 and 1995, and on height and crown volume growth of willows in 1995. Over 50% of stem density increase on transects was attributable to expansion within two large clones of Salix melanopsis inside exclosures. Excluding these two clones, overall woody plant density increased by 72% from 3.7 plants per 100 m² of transect in 1991 to 6.3 plants per 100 m² of transect in 1995. Title: Ecology of woody riparian vegetation in tributaries of the Upper Grande Ronde River basin, Oregon Author: Lytjen, Danna J. Two studies on Catherine Creek and Meadow Creek of the Upper Grande Ronde River basin, quantified several physical and biotic influences on woody riparian community composition and structure. The Catherine Creek study examined the association of woody riparian species with elevational and geomorphic gradients. The Meadow Creek study examined the influence of mammal herbivory on composition and abundance of woody riparian species. At Catherine Creek, twenty nine plots were established at 50 m intervals of elevation from near the stream origin at 2207 m in the Wallowa Mountains to the foothills of the Grande Ronde Valley at 988 m. Woody plant community composition was associated with the dominant environmental variable, elevation. Distribution of dominant riparian species was strongly associated with fluvial surfaces. Black cottonwood (Populus balsamifera) was associated with gravel and cobble bars proximal to the stream channel, and along with ponderosa pine (Pinus ponderosa) was also associated with elevated boulder bars. Alders (A. incana and A. viridis) and willows (Salix bebbiana, S. boothii, S. exigua, S. lucida, S. melanopsis, S. prolixa, and S. sitchensis) were associated with annual floodplains. At Meadow Creek, grazing by cattle was ended in 1991 on the entire study reach and three deer and elk exclosures were built within the reach adjacent to the creek. Inside deer/elk exclosures from 1991 to 1995, mean heights of tagged cottonwoods, willows, and alders increased by 86% to 180%. Outside exclosures, mean heights of cottonwoods and alders increased 109% and 99% respectively, but willows showed little change in height. Both inside and outside of exclosures mean crown volume of cottonwoods increased over 1000% and mean crown volume of alders increased over 600%. Willow volume inside exclosures increased 376% in root sprouting (clonal) species and 528% in crown sprouting (non-clonal) species, while outside of exclosures volume increased 79% and 144% respectively. On both sides of exclosure fences, beaver herbivory had a significant effect on cottonwood height growth in 1994 and 1995, and on height and crown volume growth of willows in 1995. Over 50% of stem density increase on transects was attributable to expansion within two large clones of Salix melanopsis inside exclosures. Excluding these two clones, overall woody plant density increased by 72% from 3.7 plants per 100 m² of transect in 1991 to 6.3 plants per 100 m² of transect in 1995. Close

• 2783. [Article] Contribution of subyearling estuarine migrant coho salmon (Oncorhynchus kisutch) to spawning populations on the southern Oregon coast

  The typical coho salmon life history has been characterized by juvenile fish that spend their entire first year in freshwater habitats before migrating into estuaries as smolts. However, reports of early ...

  Citation × Citation Citation Abstract Copy Title: Contribution of subyearling estuarine migrant coho salmon (Oncorhynchus kisutch) to spawning populations on the southern Oregon coast Author: Nordholm, Katherine E. The typical coho salmon life history has been characterized by juvenile fish that spend their entire first year in freshwater habitats before migrating into estuaries as smolts. However, reports of early migrating coho fry (age 0), including migration downstream to estuarine habitats, date back to the 1960s. Until a few years ago, these individuals were considered to be displaced surplus fish with low chances of survival. Recent studies have suggested that subyearling estuarine migrating coho salmon could be an alternative life history in coastal populations, but their return as jacks or mature adults needed to be documented for this life history to be considered a viable strategy. The goal of our study was to track the return of spawning coho salmon that had been individually tagged in either estuarine or riverine nursery habitats, and determine return percentages for each life history strategy as well as independently verify the presence of subyearling estuarine migrating coho salmon through otolith analysis on spawning populations. We used Passive Integrated Transponder (PIT) tags to identify individual fish as they passed through a series of antennas deployed in two coastal lowland streams on the southern Oregon coast. Percentage return of estuary tagged parr (fish ≥ 60 mm tagged in spring and summer of their first year) was variable between years and streams. For the 2010 return year, subyearling estuarine migrants was 2.5 times higher than stream residents in Palouse Creek. Fork length at estuary entrance was reconstructed for one return year of spawning fish based on otolith Sr:Ca and Br:Ca. Four main life history strategies were identified based on their fork length at time of estuary/ocean entrance: early migrating fry (< 60 mm fork length), early migrating parr (60 - 70 mm fork length), early migrating parr that returned to freshwater before migrating as yearlings ("nomads"), and yearling migrating smolts (> 70 mm fork length). Overall, 30% (Larson Creek) to 42% (Palouse Creek) of the 2009 spawning run was made up of fish that displayed evidence of estuarine residence during their first year. This study confirms that subyearling estuarine migrating coho salmon survive to reproductive age and contribute to subsequent generations. The survival of this life history type likely varies between years with changing ocean and stream conditions. It is hypothesized that their life history serves as a "bet hedging" strategy that supports coastal populations in years of poor stream conditions. In the face of rising sea levels, this life history may represent a key to the future viability of coho salmon stocks in coastal watersheds. Title: Contribution of subyearling estuarine migrant coho salmon (Oncorhynchus kisutch) to spawning populations on the southern Oregon coast Author: Nordholm, Katherine E. The typical coho salmon life history has been characterized by juvenile fish that spend their entire first year in freshwater habitats before migrating into estuaries as smolts. However, reports of early migrating coho fry (age 0), including migration downstream to estuarine habitats, date back to the 1960s. Until a few years ago, these individuals were considered to be displaced surplus fish with low chances of survival. Recent studies have suggested that subyearling estuarine migrating coho salmon could be an alternative life history in coastal populations, but their return as jacks or mature adults needed to be documented for this life history to be considered a viable strategy. The goal of our study was to track the return of spawning coho salmon that had been individually tagged in either estuarine or riverine nursery habitats, and determine return percentages for each life history strategy as well as independently verify the presence of subyearling estuarine migrating coho salmon through otolith analysis on spawning populations. We used Passive Integrated Transponder (PIT) tags to identify individual fish as they passed through a series of antennas deployed in two coastal lowland streams on the southern Oregon coast. Percentage return of estuary tagged parr (fish ≥ 60 mm tagged in spring and summer of their first year) was variable between years and streams. For the 2010 return year, subyearling estuarine migrants was 2.5 times higher than stream residents in Palouse Creek. Fork length at estuary entrance was reconstructed for one return year of spawning fish based on otolith Sr:Ca and Br:Ca. Four main life history strategies were identified based on their fork length at time of estuary/ocean entrance: early migrating fry (< 60 mm fork length), early migrating parr (60 - 70 mm fork length), early migrating parr that returned to freshwater before migrating as yearlings ("nomads"), and yearling migrating smolts (> 70 mm fork length). Overall, 30% (Larson Creek) to 42% (Palouse Creek) of the 2009 spawning run was made up of fish that displayed evidence of estuarine residence during their first year. This study confirms that subyearling estuarine migrating coho salmon survive to reproductive age and contribute to subsequent generations. The survival of this life history type likely varies between years with changing ocean and stream conditions. It is hypothesized that their life history serves as a "bet hedging" strategy that supports coastal populations in years of poor stream conditions. In the face of rising sea levels, this life history may represent a key to the future viability of coho salmon stocks in coastal watersheds. Close

• 2784. [Article] Regional Scale Modeling of Climate, Cryosphere, and Freshwater Discharge in Changing Coastal Mountain Environments

  The glaciated coastal mountain watersheds that drain into the Gulf of Alaska (GOA) provide a model laboratory to explore the challenges of hydrological modeling and study the impact of climate and glacier ...

  Citation × Citation Citation Abstract Copy Title: Regional Scale Modeling of Climate, Cryosphere, and Freshwater Discharge in Changing Coastal Mountain Environments Author: Beamer, Jordan P. The glaciated coastal mountain watersheds that drain into the Gulf of Alaska (GOA) provide a model laboratory to explore the challenges of hydrological modeling and study the impact of climate and glacier cover change on regional hydrology. The region is data-sparse and contains a complex assemblage of topography and land cover, including a system of mountain glaciers that are retreating at some of the highest rates on Earth. The high rates of runoff from precipitation and glacial melt delivered by coastal rivers influence ocean circulation patterns, rates of global sea level rise, and provide spawning habitat for the large salmon populations. Physically-based hydrological modeling of the major water budget components of the GOA, driven using historical reanalysis weather data and land cover, reveals that the modeled water budget components, particularly precipitation input, vary widely between commonly-used weather products. The majority of the large freshwater flux into the GOA is derived from distributed coastal streams rather than the large inland rivers. The modeled seasonal aggregated GOA hydrograph is dominated by the spring and early summer snowmelt, and supplemented by late summer glacial ice melt. Model results demonstrate good agreement with NASA Gravity Recovery and Climate Experiment (GRACE) satellite data in terms of annual amplitudes and long term losses (ice loss), and suggest that existing GRACE solutions, previously reported to represent glacier mass balance alone, are actually measuring the full water budget of land and ice surfaces. An ensemble of climate models and future emissions scenarios were paired with systematically altered land cover to test the sensitivity of the hydrologic system to changes in regional climate patterns and glacier coverage representative of late twenty first century conditions. Compared with the hindcast simulations, the model results forced with increased regional air temperatures and precipitation inputs and reduced glacier cover produce an increase in the annual GOA freshwater discharge volume. The seasonal GOA hydrograph is flattened due to increased winter runoff from more winter rainfall and less snow accumulation, and lower levels of snowmelt and glacier ice contribution. Large uncertainties exist in the direction of change in the glacier runoff component, primarily due to uncertainties that exist in predicting glacier response to climate change. Hydrological modeling with high resolution and inclusion of relevant physical processes can produce significantly improved products that are of high value to and in demand by numerous other scientific communities. However, the value and accuracy of the output from the hydrologic model is highly dependent on the weather forcing quality. Given the considerable importance of quality weather forcing for hydrologic modeling, it is imperative to assess the suitability of multiple products by evaluating local and regional performance and accounting for uncertainty. Additional efforts should be made to improve the spatial resolution of the reanalysis through downscaling and to strategically increase the number of weather stations at high elevations and incorporate that data into weather forcing datasets. Title: Regional Scale Modeling of Climate, Cryosphere, and Freshwater Discharge in Changing Coastal Mountain Environments Author: Beamer, Jordan P. The glaciated coastal mountain watersheds that drain into the Gulf of Alaska (GOA) provide a model laboratory to explore the challenges of hydrological modeling and study the impact of climate and glacier cover change on regional hydrology. The region is data-sparse and contains a complex assemblage of topography and land cover, including a system of mountain glaciers that are retreating at some of the highest rates on Earth. The high rates of runoff from precipitation and glacial melt delivered by coastal rivers influence ocean circulation patterns, rates of global sea level rise, and provide spawning habitat for the large salmon populations. Physically-based hydrological modeling of the major water budget components of the GOA, driven using historical reanalysis weather data and land cover, reveals that the modeled water budget components, particularly precipitation input, vary widely between commonly-used weather products. The majority of the large freshwater flux into the GOA is derived from distributed coastal streams rather than the large inland rivers. The modeled seasonal aggregated GOA hydrograph is dominated by the spring and early summer snowmelt, and supplemented by late summer glacial ice melt. Model results demonstrate good agreement with NASA Gravity Recovery and Climate Experiment (GRACE) satellite data in terms of annual amplitudes and long term losses (ice loss), and suggest that existing GRACE solutions, previously reported to represent glacier mass balance alone, are actually measuring the full water budget of land and ice surfaces. An ensemble of climate models and future emissions scenarios were paired with systematically altered land cover to test the sensitivity of the hydrologic system to changes in regional climate patterns and glacier coverage representative of late twenty first century conditions. Compared with the hindcast simulations, the model results forced with increased regional air temperatures and precipitation inputs and reduced glacier cover produce an increase in the annual GOA freshwater discharge volume. The seasonal GOA hydrograph is flattened due to increased winter runoff from more winter rainfall and less snow accumulation, and lower levels of snowmelt and glacier ice contribution. Large uncertainties exist in the direction of change in the glacier runoff component, primarily due to uncertainties that exist in predicting glacier response to climate change. Hydrological modeling with high resolution and inclusion of relevant physical processes can produce significantly improved products that are of high value to and in demand by numerous other scientific communities. However, the value and accuracy of the output from the hydrologic model is highly dependent on the weather forcing quality. Given the considerable importance of quality weather forcing for hydrologic modeling, it is imperative to assess the suitability of multiple products by evaluating local and regional performance and accounting for uncertainty. Additional efforts should be made to improve the spatial resolution of the reanalysis through downscaling and to strategically increase the number of weather stations at high elevations and incorporate that data into weather forcing datasets. Close

• 2785. [Article] The conversion of allochthonous material by stream detritivores

  The role of detritivores in the conversion of allochthonous leaf material in two small streams in the Cascade Range of Oregon was studied. Their importance in relation to other consumers was estimated ...

  Citation × Citation Citation Abstract Copy Title: The conversion of allochthonous material by stream detritivores Author: Grafius, Edward John The role of detritivores in the conversion of allochthonous leaf material in two small streams in the Cascade Range of Oregon was studied. Their importance in relation to other consumers was estimated from emergence and benthic standing crop data. Ingestion rates and efficiencies of utilization of bigleaf maple (Acer macrophyllum) and red alder (Alnus rubra) leaves by several species of stream detritivores, one species of stonefly and several species of caddis lies, were measured under field or laboratory conditions. Mean consumption rates varied from 0. 04 mg/mg/day for Halesochila taylori larvae (Trichoptera:Limnephilidae) feeding on maple leaves to 0.60 mg /mg /day' for Lepidostoma sp. larvae (Trichoptera :Lepidostomatidae) feeding on alder and maple leaves. Ecclisomyia sp. larvae (Trichoptera:Limnephilidae) consumed 0.10 mg/mg/day of maple leaves in the field. All consumption rates were calculated assuming constant feeding rates by the insects and constant rates of leaf decomposition without insects, but a model is discussed that allows non-linear feeding and leaf decomposition rates. Efficiency of food utilization was measured either as assimilation efficiency, the ratio of assimilated food (ingestion minus egestion) to consumption; or as gross growth efficiency, the slope of the growth:consumption line calculated by linear regression analysis. Assimilation efficiencies ranged from 7.4% for Heteroplectron californicum larvae (Trichoptera:Calamoceratidae) fed on maple leaves to 12% for Lepidostoma sp. larvae fed on alder and maple leaves. In order to assess the role of microbial communities in leaf utilization by Pteronarcys princeps (Plecoptera:Pteronarcidae), nymphs were fed untreated maple leaves and maple leaves treated to reduce bacterial or fungal populations, for a period of 54 days. Gross growth efficiency when fed on untreated leaves was 4.94% compared with 1.03% for the insects fed antibacterial treated leaves. When fed fungicide treated leaves, the mean consumption rate was less than 10% of the consumption of untreated leaves and mortality was 85% compared with 15% for the insects fed untreated leaves. It was concluded that bacteria play a major role in the utilization of leaves by Pteronarcys princeps and that fungi are important as astimulus to feeding, although they may also aid in utilization of the leaves. To aid in classifying the emergence and benthos data into trophic categories, an extensive literature review of the foods of aquatic insects was compiled. The estimated yearly emergence of aquatic insects from Watershed 10 was 81 mg/m² /yr. of algivores, 253 mg/m²/yr. of detritivores, and 135 mg/m²/yr. of carnivores. The mean standing crop of aquatic insects in an old-growth location in Mack Creek was 0.85 g/m² of algivores, 3.10 g/m² of detritivores, and 2.31 g/m² of carnivores; and 0.83 g/m² of algivores, 1.57 g/m² of detritivores, and 4.04 g/m² of carnivores in a clear-cut location. A model is included describing the cycling of energy within the detrital component of the stream system, reflecting the importance of the fecal material and leaf fragments that return to the detrital pool. Title: The conversion of allochthonous material by stream detritivores Author: Grafius, Edward John The role of detritivores in the conversion of allochthonous leaf material in two small streams in the Cascade Range of Oregon was studied. Their importance in relation to other consumers was estimated from emergence and benthic standing crop data. Ingestion rates and efficiencies of utilization of bigleaf maple (Acer macrophyllum) and red alder (Alnus rubra) leaves by several species of stream detritivores, one species of stonefly and several species of caddis lies, were measured under field or laboratory conditions. Mean consumption rates varied from 0. 04 mg/mg/day for Halesochila taylori larvae (Trichoptera:Limnephilidae) feeding on maple leaves to 0.60 mg /mg /day' for Lepidostoma sp. larvae (Trichoptera :Lepidostomatidae) feeding on alder and maple leaves. Ecclisomyia sp. larvae (Trichoptera:Limnephilidae) consumed 0.10 mg/mg/day of maple leaves in the field. All consumption rates were calculated assuming constant feeding rates by the insects and constant rates of leaf decomposition without insects, but a model is discussed that allows non-linear feeding and leaf decomposition rates. Efficiency of food utilization was measured either as assimilation efficiency, the ratio of assimilated food (ingestion minus egestion) to consumption; or as gross growth efficiency, the slope of the growth:consumption line calculated by linear regression analysis. Assimilation efficiencies ranged from 7.4% for Heteroplectron californicum larvae (Trichoptera:Calamoceratidae) fed on maple leaves to 12% for Lepidostoma sp. larvae fed on alder and maple leaves. In order to assess the role of microbial communities in leaf utilization by Pteronarcys princeps (Plecoptera:Pteronarcidae), nymphs were fed untreated maple leaves and maple leaves treated to reduce bacterial or fungal populations, for a period of 54 days. Gross growth efficiency when fed on untreated leaves was 4.94% compared with 1.03% for the insects fed antibacterial treated leaves. When fed fungicide treated leaves, the mean consumption rate was less than 10% of the consumption of untreated leaves and mortality was 85% compared with 15% for the insects fed untreated leaves. It was concluded that bacteria play a major role in the utilization of leaves by Pteronarcys princeps and that fungi are important as astimulus to feeding, although they may also aid in utilization of the leaves. To aid in classifying the emergence and benthos data into trophic categories, an extensive literature review of the foods of aquatic insects was compiled. The estimated yearly emergence of aquatic insects from Watershed 10 was 81 mg/m² /yr. of algivores, 253 mg/m²/yr. of detritivores, and 135 mg/m²/yr. of carnivores. The mean standing crop of aquatic insects in an old-growth location in Mack Creek was 0.85 g/m² of algivores, 3.10 g/m² of detritivores, and 2.31 g/m² of carnivores; and 0.83 g/m² of algivores, 1.57 g/m² of detritivores, and 4.04 g/m² of carnivores in a clear-cut location. A model is included describing the cycling of energy within the detrital component of the stream system, reflecting the importance of the fecal material and leaf fragments that return to the detrital pool. Close

• 2786. [Article] Benthic algal flora of four rivers of the middle Willamette River Basin

  Fresh-water benthic river algae were collected from selected sites in Willamette River tributaries; two sampling sites were in the Yamhill River system and four sampling sites were in the Santiam River ...

  Citation × Citation Citation Abstract Copy Title: Benthic algal flora of four rivers of the middle Willamette River Basin Author: Todd, Leona Esther Fresh-water benthic river algae were collected from selected sites in Willamette River tributaries; two sampling sites were in the Yamhill River system and four sampling sites were in the Santiam River system. Twelve samples were taken at each collection site in the Yamhill River system at approximately monthly intervals from June 1967 through June 1968. Fourteen samples were taken at all sampling sites, excepting one, in the Santiam River system at approximately monthly intervals from June 1967 through September 1968. A total of 24 genera of benthic algae other than diatoms were identified from the two river systems, 14 genera from the Yamhill River system and 22 genera from the Santiam River system. Six genera were common to both river systems, Anabaena, Oseillatoria, Schizothrix, Spirulina, Mougeotia and Oedogonium. Ten genera were found at only one of the collecting stations. By far, the most common genus was Schizothrix; it was found in 92 percent of the samples. The greatest diversity in the samples was found in the August 27, 1967 Santiam and September 2, 1967 Yamhill samples. The smallest number of genera were found in the March collections. A total of 14,986 individual diatoms were identified and counted. Sixty-two species of diatoms were found in this study; 55 were found in the Yamhill River system and 57 were found in the Santiam River system. Of the 13 species not found in common in the two collecting sites in the Yamhill River system, all excepting Fragilaria vaucheriae were found in very low numbers and in only a few samples. Those species not occurring in common in the Santiam River system were found in low numbers excepting for Cymbella affinis, C. ventricosa and Fragilaria capucina. The Yamhill River system and Santiam River system had 50 species in common and 24 species were collected at all six sampling stations. Statistical analyses of the diatom data were done by using *AIDONE and *AIDN computer programs. Comparative studies of diversity using Simpson's Diversity Index (SDI), dominance, Redundancy Index (R'), similarity, Similarity Index (SIMI) and niche breadth were made. Comparisons were made within and between rivers. The highest diversity and the lowest dominance occurred in the North Yamhill River; the highest dominance and the lowest diversity occurred at the Lebanon Dam on the South Santiam River. Stations on the Yamhill River system had a greater mean number of species per sample than the Santiam River system stations. In general, species with high niche breadth values in one river system also had high niche breadth values in the other system. A greater similarity within a river system than between the two river systems was shown. Title: Benthic algal flora of four rivers of the middle Willamette River Basin Author: Todd, Leona Esther Fresh-water benthic river algae were collected from selected sites in Willamette River tributaries; two sampling sites were in the Yamhill River system and four sampling sites were in the Santiam River system. Twelve samples were taken at each collection site in the Yamhill River system at approximately monthly intervals from June 1967 through June 1968. Fourteen samples were taken at all sampling sites, excepting one, in the Santiam River system at approximately monthly intervals from June 1967 through September 1968. A total of 24 genera of benthic algae other than diatoms were identified from the two river systems, 14 genera from the Yamhill River system and 22 genera from the Santiam River system. Six genera were common to both river systems, Anabaena, Oseillatoria, Schizothrix, Spirulina, Mougeotia and Oedogonium. Ten genera were found at only one of the collecting stations. By far, the most common genus was Schizothrix; it was found in 92 percent of the samples. The greatest diversity in the samples was found in the August 27, 1967 Santiam and September 2, 1967 Yamhill samples. The smallest number of genera were found in the March collections. A total of 14,986 individual diatoms were identified and counted. Sixty-two species of diatoms were found in this study; 55 were found in the Yamhill River system and 57 were found in the Santiam River system. Of the 13 species not found in common in the two collecting sites in the Yamhill River system, all excepting Fragilaria vaucheriae were found in very low numbers and in only a few samples. Those species not occurring in common in the Santiam River system were found in low numbers excepting for Cymbella affinis, C. ventricosa and Fragilaria capucina. The Yamhill River system and Santiam River system had 50 species in common and 24 species were collected at all six sampling stations. Statistical analyses of the diatom data were done by using *AIDONE and *AIDN computer programs. Comparative studies of diversity using Simpson's Diversity Index (SDI), dominance, Redundancy Index (R'), similarity, Similarity Index (SIMI) and niche breadth were made. Comparisons were made within and between rivers. The highest diversity and the lowest dominance occurred in the North Yamhill River; the highest dominance and the lowest diversity occurred at the Lebanon Dam on the South Santiam River. Stations on the Yamhill River system had a greater mean number of species per sample than the Santiam River system stations. In general, species with high niche breadth values in one river system also had high niche breadth values in the other system. A greater similarity within a river system than between the two river systems was shown. Close

• 2787. [Article] Home range and habitat use by Roosevelt elk in Olympic National Park, Washington

  This research provides information on the distribution of an unexploited Roosevelt elk population in unaltered habitat in Olympic National Park. Radio-telemetry was used to document home range and habitat ...

  Citation × Citation Citation Abstract Copy Title: Home range and habitat use by Roosevelt elk in Olympic National Park, Washington Author: Jenkins, Kurt Jeffrey This research provides information on the distribution of an unexploited Roosevelt elk population in unaltered habitat in Olympic National Park. Radio-telemetry was used to document home range and habitat use by 11 adult cow elk in the Hoh Valley during March 1978, from 10 June-15 September 1978, and from 1 January-20 March 1979. That information provides a baseline for comparison with managed herds adjacent to the park and identification of long term changes in the distribution of elk in the Hoh Valley. Four groups of cow elk were identified in the study area. Cow groups were stable; elk within a group used a common home range and were highly associated. Home ranges of elk from adjacent groups overlapped but there was no permanent interchange of collared elk between groups during the period of study. There was no significant difference between mean summer and mean winter home range size; however, summer home range was larger than winter home range in five, of seven, comparisons. Average home range area of collared elk was 1034 ha during summer and 1003 ha during winter. Daily movement of elk was greater during summer than during winter; minimum daily movement distance averaged 843 m during summer and 676 m during winter. Movement of cow elk with newly born calves in June was considerably less than movement of elk without calves. The habitat use of radio-equipped elk was studied in relation to 13 habitat units on national park land and 11 units on non-park land. Collared elk were found primarily in habitat units on the valley floor during both seasons, although there was seasonal variation in the use of those units. Elk were least selective of habitat during winter, most selective during late winter and moderately selective during summer. Alder flats were selected by each collared elk during late winter and were identified as important elk habitat in the Hoh Valley because use of such areas was prevalent during a nutritionally important time of year for cow elk. Other patterns of habitat use were discussed in relation to thermal and nutritional characteristics of the watershed. Title: Home range and habitat use by Roosevelt elk in Olympic National Park, Washington Author: Jenkins, Kurt Jeffrey This research provides information on the distribution of an unexploited Roosevelt elk population in unaltered habitat in Olympic National Park. Radio-telemetry was used to document home range and habitat use by 11 adult cow elk in the Hoh Valley during March 1978, from 10 June-15 September 1978, and from 1 January-20 March 1979. That information provides a baseline for comparison with managed herds adjacent to the park and identification of long term changes in the distribution of elk in the Hoh Valley. Four groups of cow elk were identified in the study area. Cow groups were stable; elk within a group used a common home range and were highly associated. Home ranges of elk from adjacent groups overlapped but there was no permanent interchange of collared elk between groups during the period of study. There was no significant difference between mean summer and mean winter home range size; however, summer home range was larger than winter home range in five, of seven, comparisons. Average home range area of collared elk was 1034 ha during summer and 1003 ha during winter. Daily movement of elk was greater during summer than during winter; minimum daily movement distance averaged 843 m during summer and 676 m during winter. Movement of cow elk with newly born calves in June was considerably less than movement of elk without calves. The habitat use of radio-equipped elk was studied in relation to 13 habitat units on national park land and 11 units on non-park land. Collared elk were found primarily in habitat units on the valley floor during both seasons, although there was seasonal variation in the use of those units. Elk were least selective of habitat during winter, most selective during late winter and moderately selective during summer. Alder flats were selected by each collared elk during late winter and were identified as important elk habitat in the Hoh Valley because use of such areas was prevalent during a nutritionally important time of year for cow elk. Other patterns of habitat use were discussed in relation to thermal and nutritional characteristics of the watershed. Close

• 2788. [Article] Nesting and foraging ecology of band-tailed pigeons in western Oregon

  Pacific Coast band-tailed pigeons (Columba fasciata) have declined markedly during the past several decades. Despite implementation of increasingly restrictive hunting regulations, populations have shown ...

  Citation × Citation Citation Abstract Copy Title: Nesting and foraging ecology of band-tailed pigeons in western Oregon Author: Leonard, Jerome Patrick Pacific Coast band-tailed pigeons (Columba fasciata) have declined markedly during the past several decades. Despite implementation of increasingly restrictive hunting regulations, populations have shown minimal signs of recovery. I radio-marked 127 adult band-tailed pigeons in the central Oregon Coast Range in April-May of 1993-95 to document nesting chronology and productivity, and characterize nesting and feeding habitats. One-hundred and thirty-seven nests initiated by 65 different birds were monitored. Multiple brooding was predominant; 45 birds initiated 2-3 nests each with 7 birds producing 3 successful nests each in one nesting season. All nests had a clutch size of 1. The reproductive period started in late-April and went through mid- to late-October. Nesting attempts peaked mid- to late-June, and 21% of all young fledged after September 15. Nest re-use was rare, but 78% of the consecutive nests I observed by individual birds eliminated nesting intervals by overlapping nesting cycles. Nesting overlap averaged 7 days. Nest survival probabilities were consistent between years with a pooled estimate of 0.689 (95% C.I = 0.613-0.775). Band-tails nested in a variety of tree and shrub species, with 70% of the nests observed in Douglas-fir (Pseudotsuga menzesii). Only 17% of all nests were in deciduous trees or shrubs. Nest height was highly variable and averaged 10.3 m. They also used a variety of stand conditions (open and closed) and seral/community types (sapling-pole to old-growth in deciduous and conifer communities). However, the majority of nests (77%) were in stands classified as conifer community with 55% in the closed-canopy, sapling-pole seral condition. Feed areas were diverse in their physical and vegetative characteristics and were located in both riparian and upland zones. The principal food component within most of these sites was either Pacific red elder (Sambucas racemosa) or cascara buckthorn (Rhamnus purshianus). Band-tailed pigeons were highly mobile throughout their nesting season. They traveled an average of 5.02 km to feed areas and had a mean home range size of 11,121 ha. Due to their mobility, and diverse habitat use, band-tailed pigeons would be an important species for consideration in large watershed management designs. Title: Nesting and foraging ecology of band-tailed pigeons in western Oregon Author: Leonard, Jerome Patrick Pacific Coast band-tailed pigeons (Columba fasciata) have declined markedly during the past several decades. Despite implementation of increasingly restrictive hunting regulations, populations have shown minimal signs of recovery. I radio-marked 127 adult band-tailed pigeons in the central Oregon Coast Range in April-May of 1993-95 to document nesting chronology and productivity, and characterize nesting and feeding habitats. One-hundred and thirty-seven nests initiated by 65 different birds were monitored. Multiple brooding was predominant; 45 birds initiated 2-3 nests each with 7 birds producing 3 successful nests each in one nesting season. All nests had a clutch size of 1. The reproductive period started in late-April and went through mid- to late-October. Nesting attempts peaked mid- to late-June, and 21% of all young fledged after September 15. Nest re-use was rare, but 78% of the consecutive nests I observed by individual birds eliminated nesting intervals by overlapping nesting cycles. Nesting overlap averaged 7 days. Nest survival probabilities were consistent between years with a pooled estimate of 0.689 (95% C.I = 0.613-0.775). Band-tails nested in a variety of tree and shrub species, with 70% of the nests observed in Douglas-fir (Pseudotsuga menzesii). Only 17% of all nests were in deciduous trees or shrubs. Nest height was highly variable and averaged 10.3 m. They also used a variety of stand conditions (open and closed) and seral/community types (sapling-pole to old-growth in deciduous and conifer communities). However, the majority of nests (77%) were in stands classified as conifer community with 55% in the closed-canopy, sapling-pole seral condition. Feed areas were diverse in their physical and vegetative characteristics and were located in both riparian and upland zones. The principal food component within most of these sites was either Pacific red elder (Sambucas racemosa) or cascara buckthorn (Rhamnus purshianus). Band-tailed pigeons were highly mobile throughout their nesting season. They traveled an average of 5.02 km to feed areas and had a mean home range size of 11,121 ha. Due to their mobility, and diverse habitat use, band-tailed pigeons would be an important species for consideration in large watershed management designs. Close

• 2789. [Article] Soil and understory vegetation characteristics of a tractor-logged forest in eastern Oregon

  A 1.5 ha mixed conifer stand in the Blue Mountains of Oregon was intensively examined to assess the impact of logging disturbance on soils and herbaceous vegetation. Sampling was conducted six years after ...

  Citation × Citation Citation Abstract Copy Title: Soil and understory vegetation characteristics of a tractor-logged forest in eastern Oregon Author: Snider, Michael Duane A 1.5 ha mixed conifer stand in the Blue Mountains of Oregon was intensively examined to assess the impact of logging disturbance on soils and herbaceous vegetation. Sampling was conducted six years after much of the timber overstory was removed in a shelterwood cut and yarded by crawler tractor. A year after harvest slash was machine-piled and burned. Skid trails and other areas of disturbance were seeded with a mixture of perennial grasses. Logging impact was divided into five "disturbance classes'* as treatments: general, berm, slash fire ring, skid trail, and undisturbed. Analysis of variance was used to test treatment differences. Characteristics of skid trails were analyzed separately from those of non-skid trail areas. Soil compaction was evident on skid trails from substantially lower rates of infiltration and saturated hydraulic conductivity (SHC), and a higher average soil strength, relative to undisturbed areas. Skid trail compaction probably resulted from mixing of denser subsoils with the low-density volcanic ash soils at the surface, and from compression by tractor activity. Bulk density of skid trails was not statistically different from that of undisturbed areas. Soil densities of all classes of disturbance were generally lower than 0.9 g/cm³. Non-skid trail areas were not compacted. Soil water conductance rates markedly differed among disturbance classes, but were considerably higher than storm intensities projected for the region. High sample variability of both infiltration and SHC rates made interpreation of statistical comparisons among treatments difficult. Some watershed protection values were diminished on the disturbed areas. Litter cover of skid trails, general disturbance areas, and berms was 27, 45, and 68 percent lower, respectively, than that of undisturbed areas. Depth of litter decreased correspondingly among the disturbed treatments. Litter was nearly absent on the fire rings. Another agent in soil stabilization, belowground biomass, was two-thirds less on skid trails, in comparision with undisturbed areas. Amounts of soil organic matter in the surface 3 cm were significantly lower for the four types of ground disturbance, relative to undisturbed areas; however, organic matter was higher at some subsurface levels of berms, fire rings, and skid trails. Bulk density of non-skid trail soils was inversely correlated with organic matter content. There were no statistically significant differences among treatments for soil water retained at four potentials, for coarse mineral fragment content, or for fine earth particle size distribution. Aboveground vegetation production of the seeded skid trails was 66 percent greater than that of undisturbed areas. Understory plant cover of skid trails and undisturbed areas was equivalent. Correlation between aboveground herbaceous production and soil strength at the 5-10 cm depth of skid trails was not statistically significant. Title: Soil and understory vegetation characteristics of a tractor-logged forest in eastern Oregon Author: Snider, Michael Duane A 1.5 ha mixed conifer stand in the Blue Mountains of Oregon was intensively examined to assess the impact of logging disturbance on soils and herbaceous vegetation. Sampling was conducted six years after much of the timber overstory was removed in a shelterwood cut and yarded by crawler tractor. A year after harvest slash was machine-piled and burned. Skid trails and other areas of disturbance were seeded with a mixture of perennial grasses. Logging impact was divided into five "disturbance classes'* as treatments: general, berm, slash fire ring, skid trail, and undisturbed. Analysis of variance was used to test treatment differences. Characteristics of skid trails were analyzed separately from those of non-skid trail areas. Soil compaction was evident on skid trails from substantially lower rates of infiltration and saturated hydraulic conductivity (SHC), and a higher average soil strength, relative to undisturbed areas. Skid trail compaction probably resulted from mixing of denser subsoils with the low-density volcanic ash soils at the surface, and from compression by tractor activity. Bulk density of skid trails was not statistically different from that of undisturbed areas. Soil densities of all classes of disturbance were generally lower than 0.9 g/cm³. Non-skid trail areas were not compacted. Soil water conductance rates markedly differed among disturbance classes, but were considerably higher than storm intensities projected for the region. High sample variability of both infiltration and SHC rates made interpreation of statistical comparisons among treatments difficult. Some watershed protection values were diminished on the disturbed areas. Litter cover of skid trails, general disturbance areas, and berms was 27, 45, and 68 percent lower, respectively, than that of undisturbed areas. Depth of litter decreased correspondingly among the disturbed treatments. Litter was nearly absent on the fire rings. Another agent in soil stabilization, belowground biomass, was two-thirds less on skid trails, in comparision with undisturbed areas. Amounts of soil organic matter in the surface 3 cm were significantly lower for the four types of ground disturbance, relative to undisturbed areas; however, organic matter was higher at some subsurface levels of berms, fire rings, and skid trails. Bulk density of non-skid trail soils was inversely correlated with organic matter content. There were no statistically significant differences among treatments for soil water retained at four potentials, for coarse mineral fragment content, or for fine earth particle size distribution. Aboveground vegetation production of the seeded skid trails was 66 percent greater than that of undisturbed areas. Understory plant cover of skid trails and undisturbed areas was equivalent. Correlation between aboveground herbaceous production and soil strength at the 5-10 cm depth of skid trails was not statistically significant. Close

• 2790. [Article] International river basin management in the face of change : Syr Darya Basin case study

  The conflict over water resources exploitation and sharing in the Aral Sea Basin is one of the most pressing environmental issues yet to be resolved in Central Asia. The fall of the Soviet Union in 1991 ...

  Citation × Citation Citation Abstract Copy Title: International river basin management in the face of change : Syr Darya Basin case study Author: Pak, Mariya The conflict over water resources exploitation and sharing in the Aral Sea Basin is one of the most pressing environmental issues yet to be resolved in Central Asia. The fall of the Soviet Union in 1991 and establishment of the New Independent States (NIS) within the Aral Sea Bain led to conflicting interests vested in water resources with no mediator to solve these water issues. Presently, the Amu Darya and Syr Darya upstream states of Kyrgyzstan and Tajikistan desire to employ water resources for hydropower; while downstream Kazakhstan, Turkmenistan and Uzbekistan wish to continue practicing irrigated agriculture. This scarce and over-allocated resource, facing the needs of a growing population and climate change uncertainties, should be managed collaboratively and sustainably to be able to meet and withstand the upcoming challenges. This dissertation examines water management practices in the face of government regime change both in large and small river basins within Central Asia by analyzing international water agreements, correspondence between water managers, official reports, maps, and other archival documents. The analysis shows the inter-republican dynamics in water sector starting from 1950s up to early 2000s. The analysis of water relations within the Syr Darya Basin shows that there are different approaches to the change in political regime in both large and small basins. The results reveal that conflict over water resources in Central Asia existed long before the fall of the Soviet Union both in the large Syr Darya Basin, as well as within its small tributaries. The Soviet planned economy, along with the basin planning framework, set competition for water between the riparian states. Analysis of the infrastructure construction negotiations in these small shared tributaries showed that the former Soviet Republics used non-cooperative negotiation strategies to outcompete their rivals. This dissertation calls for regional cooperation in water management as it is shown that hydro-political competition in the basin may lead only to short term benefits, on the long run however, it is proven lead to heavy economic, social, political, and environmental costs. Title: International river basin management in the face of change : Syr Darya Basin case study Author: Pak, Mariya The conflict over water resources exploitation and sharing in the Aral Sea Basin is one of the most pressing environmental issues yet to be resolved in Central Asia. The fall of the Soviet Union in 1991 and establishment of the New Independent States (NIS) within the Aral Sea Bain led to conflicting interests vested in water resources with no mediator to solve these water issues. Presently, the Amu Darya and Syr Darya upstream states of Kyrgyzstan and Tajikistan desire to employ water resources for hydropower; while downstream Kazakhstan, Turkmenistan and Uzbekistan wish to continue practicing irrigated agriculture. This scarce and over-allocated resource, facing the needs of a growing population and climate change uncertainties, should be managed collaboratively and sustainably to be able to meet and withstand the upcoming challenges. This dissertation examines water management practices in the face of government regime change both in large and small river basins within Central Asia by analyzing international water agreements, correspondence between water managers, official reports, maps, and other archival documents. The analysis shows the inter-republican dynamics in water sector starting from 1950s up to early 2000s. The analysis of water relations within the Syr Darya Basin shows that there are different approaches to the change in political regime in both large and small basins. The results reveal that conflict over water resources in Central Asia existed long before the fall of the Soviet Union both in the large Syr Darya Basin, as well as within its small tributaries. The Soviet planned economy, along with the basin planning framework, set competition for water between the riparian states. Analysis of the infrastructure construction negotiations in these small shared tributaries showed that the former Soviet Republics used non-cooperative negotiation strategies to outcompete their rivals. This dissertation calls for regional cooperation in water management as it is shown that hydro-political competition in the basin may lead only to short term benefits, on the long run however, it is proven lead to heavy economic, social, political, and environmental costs. Close