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• 221. [Article] The relationship of personal and social resources on coping and individual well-being in caregivers of dementia patients

  Alzheimer's disease, a chronic and irreversible form of dementia, has been recognized as one of the most critical medical-social-economic problems facing our country. As Alzheimer's disease and other related ...

  Citation × Citation Citation Abstract Copy Title: The relationship of personal and social resources on coping and individual well-being in caregivers of dementia patients Author: Wright, Scott D. Alzheimer's disease, a chronic and irreversible form of dementia, has been recognized as one of the most critical medical-social-economic problems facing our country. As Alzheimer's disease and other related dementias progress, the patient becomes increasingly dependent upon family and natural support systems to provide care. This dependency can place the caregiver in a role that is both difficult and demanding. The purpose of this study was to construct and assess a theoretical model which investigated the effects of patient functioning, personal and social resources on coping behaviors and adaptational outcomes (caregiver well-being) in caregivers of dementia patients. The theoretical model was tested with data from caregivers of patients with dementia throughout a 14 state region primarily in the Southwestern and Northwestern United States. A total of 502 caregivers participated in this study and only those caregivers who were related to the dementia patient were selected for in this study. Data was obtained through self-report questionnaires mailed either directly to the homes of the family caregiver or sent to support group leaders who them mailed the questionnaire to the caregivers. The theoretical model, which proposed latent variables, was assessed with the LISREL V computer program. Several other statistical analyses were also utilized, such as: one-way ANOVA's, Pearson product-moment correlations, factor analyses and multiple regression. Collectively the results from the LISREL analysis indicated a poor fit of the data to the proposed theoretical model. Subsequent analyses were conducted to further explore the validity of the proposed constructs and the structural relationships between them. Based on these results, it was found that several constructs were more integrated and conceptually complex than previously proposed. Internal control beliefs, problem-focused and refraining coping behaviors, and social support satisfaction were found to be predictors of positive adaptational outcomes in caregivers. Chance and Powerful Others control beliefs, avoidant/evasive and regressive coping behaviors were found to be predictors of negative adaptational outcomes. These findings lent support for the development of intervention programs which assist caregivers in developing specific skills necessary for coping with the potential long-term role of careprovider. The findings also indicated the strong relations between social support and a caregiver's ability to adapt to the caregiving role. Title: The relationship of personal and social resources on coping and individual well-being in caregivers of dementia patients Author: Wright, Scott D. Alzheimer's disease, a chronic and irreversible form of dementia, has been recognized as one of the most critical medical-social-economic problems facing our country. As Alzheimer's disease and other related dementias progress, the patient becomes increasingly dependent upon family and natural support systems to provide care. This dependency can place the caregiver in a role that is both difficult and demanding. The purpose of this study was to construct and assess a theoretical model which investigated the effects of patient functioning, personal and social resources on coping behaviors and adaptational outcomes (caregiver well-being) in caregivers of dementia patients. The theoretical model was tested with data from caregivers of patients with dementia throughout a 14 state region primarily in the Southwestern and Northwestern United States. A total of 502 caregivers participated in this study and only those caregivers who were related to the dementia patient were selected for in this study. Data was obtained through self-report questionnaires mailed either directly to the homes of the family caregiver or sent to support group leaders who them mailed the questionnaire to the caregivers. The theoretical model, which proposed latent variables, was assessed with the LISREL V computer program. Several other statistical analyses were also utilized, such as: one-way ANOVA's, Pearson product-moment correlations, factor analyses and multiple regression. Collectively the results from the LISREL analysis indicated a poor fit of the data to the proposed theoretical model. Subsequent analyses were conducted to further explore the validity of the proposed constructs and the structural relationships between them. Based on these results, it was found that several constructs were more integrated and conceptually complex than previously proposed. Internal control beliefs, problem-focused and refraining coping behaviors, and social support satisfaction were found to be predictors of positive adaptational outcomes in caregivers. Chance and Powerful Others control beliefs, avoidant/evasive and regressive coping behaviors were found to be predictors of negative adaptational outcomes. These findings lent support for the development of intervention programs which assist caregivers in developing specific skills necessary for coping with the potential long-term role of careprovider. The findings also indicated the strong relations between social support and a caregiver's ability to adapt to the caregiving role. Close

• 222. [Article] Spawning, larval recruitment, and early life survival of Pacific lampreys in the South Fork Coquille River, Oregon

  Recently, there has been concern over the decline of the Pacific lamprey, Lampetra tridentata, in the northwestern United States. However, effective management has been impeded by data gaps in basic biology, ...

  Citation × Citation Citation Abstract Copy Title: Spawning, larval recruitment, and early life survival of Pacific lampreys in the South Fork Coquille River, Oregon Author: Brumo, Abel F. Recently, there has been concern over the decline of the Pacific lamprey, Lampetra tridentata, in the northwestern United States. However, effective management has been impeded by data gaps in basic biology, especially in the early life stages. Consequently, in 2004 and 2005 I examined reproductive ecology, larval recruitment, and lamprey monitoring methods in the South Fork Coquille River, a coastal Oregon stream. In Chapter 2 I monitored spawning populations at large (9.2 km) and small (focal area) scales. Relationships between adult counts at the two spatial scales and adult and redd counts at the large scale were analyzed. Weekly adult, redd, and carcass counts and tagging were also used to describe spawning and residence times, movement, size, and sex of mature adults. Large-scale adult and redd counts were highly correlated (2004, r2 = 0.867; P = 0.0069; 2005, r2 = 0.877; P = 0.0002); as were large-scale and focal area adult counts over both years combined (r2 = 0.690, P = 0.0001) and in 2004 (r2 = 0.753, P = 0.0250), but not in 2005 when densities were much lower (r2 = 0.065, P = 0.5069). Average residence time in spawning areas was less than a week for males and shorter for females, since >90% of recaptured fish were male. Two-thirds of dead fish (2:1) were male, versus only one-half of live fish (1:1), indicating additional sex-specific differences in postspawning behavior. No seasonal or spatial patterns in sex ratio or adult length were detected. Both adult and redd counts have inherent errors related to observer variability, movement during surveys, night spawning, and variable visibility due to weather and flow. To make adult and redd counts more useful for population monitoring their errors need to be better quantified and their relevance to life-cycle dynamics better understood. In Chapter 3 I monitored intra-annual cohorts of spawning adults and emergent larvae at a single spawning area to examine annual and seasonal patterns of spawning, larval recruitment, and early life survival. In 2004 spawning occurred from April 6–June 3 (59 d) and larval emergence occurred from May 6–June 28 (54 d). In 2005 both spawning and emergence were later and more protracted, from April 25–July 3 (70 d) and May 15–July 25 (71 d), respectively. Over both years, larval recruitment was highly variable and only marginally correlated with spawning stock (r2 = 0.149, P = 0.0512). Survival until larval emergence was significantly related to spawning stock size, discharge during spawning, and their interaction. Survival generally declined with increasing spawning stock and decreasing discharge, both apparently related to negative density-dependent effects, which resulted in highly variable early life survival. For example, in April 2004, 65% of larvae were produced by 28% of spawners, while in May, 35% of larvae were produced by 70% of spawners. Egg predation by speckled dace, Rhinichthys osculus, increased with temperature, but contrary to expectations, had no detectable effect on survival until emergence. This study provided justification for a multi-life stage approach to monitoring Pacific lamprey populations and understanding their dynamics. Application of this approach can provide insight into density-dependent survival and the roles of biotic and abiotic factors in larval production. Applied to the South Fork Coquille, Pacific lamprey larval production appeared to have an upper limit related, in part, to spawner density. Title: Spawning, larval recruitment, and early life survival of Pacific lampreys in the South Fork Coquille River, Oregon Author: Brumo, Abel F. Recently, there has been concern over the decline of the Pacific lamprey, Lampetra tridentata, in the northwestern United States. However, effective management has been impeded by data gaps in basic biology, especially in the early life stages. Consequently, in 2004 and 2005 I examined reproductive ecology, larval recruitment, and lamprey monitoring methods in the South Fork Coquille River, a coastal Oregon stream. In Chapter 2 I monitored spawning populations at large (9.2 km) and small (focal area) scales. Relationships between adult counts at the two spatial scales and adult and redd counts at the large scale were analyzed. Weekly adult, redd, and carcass counts and tagging were also used to describe spawning and residence times, movement, size, and sex of mature adults. Large-scale adult and redd counts were highly correlated (2004, r2 = 0.867; P = 0.0069; 2005, r2 = 0.877; P = 0.0002); as were large-scale and focal area adult counts over both years combined (r2 = 0.690, P = 0.0001) and in 2004 (r2 = 0.753, P = 0.0250), but not in 2005 when densities were much lower (r2 = 0.065, P = 0.5069). Average residence time in spawning areas was less than a week for males and shorter for females, since >90% of recaptured fish were male. Two-thirds of dead fish (2:1) were male, versus only one-half of live fish (1:1), indicating additional sex-specific differences in postspawning behavior. No seasonal or spatial patterns in sex ratio or adult length were detected. Both adult and redd counts have inherent errors related to observer variability, movement during surveys, night spawning, and variable visibility due to weather and flow. To make adult and redd counts more useful for population monitoring their errors need to be better quantified and their relevance to life-cycle dynamics better understood. In Chapter 3 I monitored intra-annual cohorts of spawning adults and emergent larvae at a single spawning area to examine annual and seasonal patterns of spawning, larval recruitment, and early life survival. In 2004 spawning occurred from April 6–June 3 (59 d) and larval emergence occurred from May 6–June 28 (54 d). In 2005 both spawning and emergence were later and more protracted, from April 25–July 3 (70 d) and May 15–July 25 (71 d), respectively. Over both years, larval recruitment was highly variable and only marginally correlated with spawning stock (r2 = 0.149, P = 0.0512). Survival until larval emergence was significantly related to spawning stock size, discharge during spawning, and their interaction. Survival generally declined with increasing spawning stock and decreasing discharge, both apparently related to negative density-dependent effects, which resulted in highly variable early life survival. For example, in April 2004, 65% of larvae were produced by 28% of spawners, while in May, 35% of larvae were produced by 70% of spawners. Egg predation by speckled dace, Rhinichthys osculus, increased with temperature, but contrary to expectations, had no detectable effect on survival until emergence. This study provided justification for a multi-life stage approach to monitoring Pacific lamprey populations and understanding their dynamics. Application of this approach can provide insight into density-dependent survival and the roles of biotic and abiotic factors in larval production. Applied to the South Fork Coquille, Pacific lamprey larval production appeared to have an upper limit related, in part, to spawner density. Close

• 223. [Article] Geology of part of the northern half of the Bend quadrangle, Jefferson and Deschutes counties, Oregon

  The mapped area is part of the middle Deschutes Basin of central Oregon, which lies in the northwestern corner of the High Lava Plains physiographic province, between the Cascade and Ochoco Mountains. ...

  Citation × Citation Citation Abstract Copy Title: Geology of part of the northern half of the Bend quadrangle, Jefferson and Deschutes counties, Oregon Author: Stensland, Donald Eugene The mapped area is part of the middle Deschutes Basin of central Oregon, which lies in the northwestern corner of the High Lava Plains physiographic province, between the Cascade and Ochoco Mountains. It is underlain by Cenozoic lavas, tuffs and sediments of continental origin. The oldest rocks in the sequence are pyroxene andesites, which crop out as prominent inliers within the area, and dense, fine-grained olivine basalts, which are exposed along the northeastern boundary of the area at Trail Crossing. They are assigned to the late Eocene - Early Oligocene Clarno Formation. Silicified tuffs of the early to middle (?) Oligocene - early Miocene John Day Formation crop out near Terrebonne, and overlie the Clarno basalts with angular unconformity east of Trail Crossing. The thickness of Clarno and John Day rocks is undetermined. The Deschutes Formation, a heterogeneous sequence of sediments, tuffs and lavas, overlies the older rocks with angular unconformity, and reaches an exposed thickness of 600 feet along the northern boundary of the area. The best exposures occur along the Deschutes and Crooked Rivers, which flow northward through the area in steep-walled canyons. On the basis of stratigraphic position, paleontological evidence and radiometric age dating, the formation is considered to be early Pliocene to early Pleistocene in age, and correlates directly with the Rattlesnake Formation of central Oregon. Members of the Deschutes Formation include prominent deposits of diatomite, and a mudflow breccia which contains enormous boulders of Clarno andesite. Epiclastic sediments include fluvial sands, conglomerates and breccias, and tuffaceous eolian sands. Individual beds are generally discontinuous wedge- or lens-shaped units. Pyroclastic sediments include thin, intercalated beds of fine vitric ash and coarse, cindery ash or lapilli, pumice lapilli beds, vitric airborne tuffs, and volcanic breccia. Individual beds are usually widespread and continuous, with a sheet-like form. Nine ash flow tuffs are recognized in the formation. They form widespread sheets, and often crop out as prominent ledges or benches within the canyons. Most of the tuffs are relatively thin, but some exceed 100 feet in thickness. Index of refraction studies indicate that silica percentages range from 56% to 68f, and the tuffs are probably dacitic in composition. Basalt flows are interbedded with Deschutes sediments, intracanyon to them, and also form extensive plateaus capping the formation. Most of the lavas form thin sheets, but others are tabular and range up to 200 feet in thickness. The plateau-forming flows at Terrebonne, and also the oldest interbedded flow, are characterized by a distinctive diktytaxitic texture and an abundance of olivine phenocrysts. However, most of the basalt flows are relatively sparse in olivine, and are sparsely to abundantly porphyritic. The presence of cinder and lava cones, basaltic intrusives, buried cinders and the Localized nature of individual flows indicate that most of the basalts were erupted from cones and fissures within the basin. The youngest rocks in the sequence consist of diktytaxitic olivine basalt, herein designated the Crooked River basalt. This unit covers the plateau in the southeastern part of the area, and caps prominent benches within canyons in the northern part of the area. It ranges in thickness from less than 10 feet on the plateau to 650 feet in the canyons. It is separated from the Deschutes Formation by a striking erosional unconformity, and is tentatively considered to be late Pleistocene in age. Most of the Deschutes strata are horizontal or gently inclined toward the center of the depositional basin. They were deposited on a surface of variable relief, and the attitudes of individual beds reflect the changing slope of the original surface. Lava-covered plateau surfaces in the southern and central part of the mapped area dip 10 to the north and northeast. A series of parallel normal faults, located in the southwestern part of the mapped area, trend N. 250 - 350 W. The present topography is due to fluvial erosion of the volcanic terrain. Title: Geology of part of the northern half of the Bend quadrangle, Jefferson and Deschutes counties, Oregon Author: Stensland, Donald Eugene The mapped area is part of the middle Deschutes Basin of central Oregon, which lies in the northwestern corner of the High Lava Plains physiographic province, between the Cascade and Ochoco Mountains. It is underlain by Cenozoic lavas, tuffs and sediments of continental origin. The oldest rocks in the sequence are pyroxene andesites, which crop out as prominent inliers within the area, and dense, fine-grained olivine basalts, which are exposed along the northeastern boundary of the area at Trail Crossing. They are assigned to the late Eocene - Early Oligocene Clarno Formation. Silicified tuffs of the early to middle (?) Oligocene - early Miocene John Day Formation crop out near Terrebonne, and overlie the Clarno basalts with angular unconformity east of Trail Crossing. The thickness of Clarno and John Day rocks is undetermined. The Deschutes Formation, a heterogeneous sequence of sediments, tuffs and lavas, overlies the older rocks with angular unconformity, and reaches an exposed thickness of 600 feet along the northern boundary of the area. The best exposures occur along the Deschutes and Crooked Rivers, which flow northward through the area in steep-walled canyons. On the basis of stratigraphic position, paleontological evidence and radiometric age dating, the formation is considered to be early Pliocene to early Pleistocene in age, and correlates directly with the Rattlesnake Formation of central Oregon. Members of the Deschutes Formation include prominent deposits of diatomite, and a mudflow breccia which contains enormous boulders of Clarno andesite. Epiclastic sediments include fluvial sands, conglomerates and breccias, and tuffaceous eolian sands. Individual beds are generally discontinuous wedge- or lens-shaped units. Pyroclastic sediments include thin, intercalated beds of fine vitric ash and coarse, cindery ash or lapilli, pumice lapilli beds, vitric airborne tuffs, and volcanic breccia. Individual beds are usually widespread and continuous, with a sheet-like form. Nine ash flow tuffs are recognized in the formation. They form widespread sheets, and often crop out as prominent ledges or benches within the canyons. Most of the tuffs are relatively thin, but some exceed 100 feet in thickness. Index of refraction studies indicate that silica percentages range from 56% to 68f, and the tuffs are probably dacitic in composition. Basalt flows are interbedded with Deschutes sediments, intracanyon to them, and also form extensive plateaus capping the formation. Most of the lavas form thin sheets, but others are tabular and range up to 200 feet in thickness. The plateau-forming flows at Terrebonne, and also the oldest interbedded flow, are characterized by a distinctive diktytaxitic texture and an abundance of olivine phenocrysts. However, most of the basalt flows are relatively sparse in olivine, and are sparsely to abundantly porphyritic. The presence of cinder and lava cones, basaltic intrusives, buried cinders and the Localized nature of individual flows indicate that most of the basalts were erupted from cones and fissures within the basin. The youngest rocks in the sequence consist of diktytaxitic olivine basalt, herein designated the Crooked River basalt. This unit covers the plateau in the southeastern part of the area, and caps prominent benches within canyons in the northern part of the area. It ranges in thickness from less than 10 feet on the plateau to 650 feet in the canyons. It is separated from the Deschutes Formation by a striking erosional unconformity, and is tentatively considered to be late Pleistocene in age. Most of the Deschutes strata are horizontal or gently inclined toward the center of the depositional basin. They were deposited on a surface of variable relief, and the attitudes of individual beds reflect the changing slope of the original surface. Lava-covered plateau surfaces in the southern and central part of the mapped area dip 10 to the north and northeast. A series of parallel normal faults, located in the southwestern part of the mapped area, trend N. 250 - 350 W. The present topography is due to fluvial erosion of the volcanic terrain. Close

• 224. [Article] Passage, migration behavior, and autoecology of adult Pacific lamprey at Winchester Dam and within the North Umpqua River Basin, Oregon, USA

  The extensive reduction in adult Pacific lamprey (Entosphenus tridentatus) counts at many hydroelectric dams in the northwestern USA signals a substantial decline in lamprey numbers across the entire region ...

  Citation × Citation Citation Abstract Copy Title: Passage, migration behavior, and autoecology of adult Pacific lamprey at Winchester Dam and within the North Umpqua River Basin, Oregon, USA Author: Lampman, Ralph Tatsuo The extensive reduction in adult Pacific lamprey (Entosphenus tridentatus) counts at many hydroelectric dams in the northwestern USA signals a substantial decline in lamprey numbers across the entire region in the past 40 to 50 years. Among the many potential causes of this decline, obstruction of migration routes has likely played a substantial role. Within the North Umpqua River basin in southwest Oregon, USA, I focused on the following three research goals: 1) to describe the passage efficiency and migration routes of adult Pacific lamprey at Winchester Dam; 2) to evaluate the seasonal movement patterns of adult Pacific lamprey and their use of holding habitat at Winchester Dam in relation to temperature conditions; and 3) to portray the diversity of upstream migratory behaviors of adult Pacific lamprey and the environmental factors that influence these behaviors. This radio telemetry study was conducted between March 2009 and August 2011 with a combination of fixed stations and manual tracking. Passage efficiency was low in both years (8% and 19%, respectively), and all tagged lamprey that successfully passed the dam used routes other than the fish ladder. Lamprey that migrated early within the run and those with relatively small tags had higher passage rates and traveled further than the other groups of lamprey. Lamprey released above of the dam or those that passed the dam on their own distributed themselves widely in the upstream environment, suggesting that the dam deterred their upstream migration. Using mark-recapture data for the two years, the adult Pacific lamprey population upstream of Winchester Dam was estimated at 960 (95% C.I. [188, 4760]) in 2009 and 556 (95% C.I. [110, 2798]) in 2010, which was considerably lower than historical counts at the dam (between 14,532-46,785 in 1965-1971). Most tagged lamprey that did not pass the dam remained at the base of the dam at the end of the summer migration (63% in 2009 and 67% in 2010). Types of habitat most frequently used by lamprey downstream from the dam included the dam surface (wooden structures with crevices), interface zones between fast and slow water, and highway bridge pilings. The lamprey movement changed considerably between August and September, and the frequency of movements decreased sharply during this period. Tagged lamprey were detected using thermal refuges immediately downstream of the dam that were 0.4 to 2.8 C° colder than the mean river temperature at the dam, and this temperature differential increased as the season progressed. Lamprey may be seeking overwintering habitat associated with hyporheic exchange flows at the dam towards the end of the summer season after their display of heightened activity early in the summer. Ninety-five percent of the overall upstream migration took place during the first spring/summer period, and only small-scale upstream movements were observed during the winter and second spring/summer (4% and 1%, respectively). The rate of upstream migration (median) was the fastest during the initial migration phase and was 1.9 km/day (ranging from 0.3 to 11.0 km/day) for tagged lamprey released above Winchester Dam. During winter, 71% of the lamprey remained in the same location where they initiated holding. Multiple regression analysis indicated that the total upstream distance traveled by individual lamprey was most strongly related to presence/absence of Winchester Dam, relative tag size, and water temperature and photoperiod conditions at release. The presence of Winchester Dam, large relative tag size, and high water temperature / short photoperiod conditions at release significantly reduced upstream migration distance. Title: Passage, migration behavior, and autoecology of adult Pacific lamprey at Winchester Dam and within the North Umpqua River Basin, Oregon, USA Author: Lampman, Ralph Tatsuo The extensive reduction in adult Pacific lamprey (Entosphenus tridentatus) counts at many hydroelectric dams in the northwestern USA signals a substantial decline in lamprey numbers across the entire region in the past 40 to 50 years. Among the many potential causes of this decline, obstruction of migration routes has likely played a substantial role. Within the North Umpqua River basin in southwest Oregon, USA, I focused on the following three research goals: 1) to describe the passage efficiency and migration routes of adult Pacific lamprey at Winchester Dam; 2) to evaluate the seasonal movement patterns of adult Pacific lamprey and their use of holding habitat at Winchester Dam in relation to temperature conditions; and 3) to portray the diversity of upstream migratory behaviors of adult Pacific lamprey and the environmental factors that influence these behaviors. This radio telemetry study was conducted between March 2009 and August 2011 with a combination of fixed stations and manual tracking. Passage efficiency was low in both years (8% and 19%, respectively), and all tagged lamprey that successfully passed the dam used routes other than the fish ladder. Lamprey that migrated early within the run and those with relatively small tags had higher passage rates and traveled further than the other groups of lamprey. Lamprey released above of the dam or those that passed the dam on their own distributed themselves widely in the upstream environment, suggesting that the dam deterred their upstream migration. Using mark-recapture data for the two years, the adult Pacific lamprey population upstream of Winchester Dam was estimated at 960 (95% C.I. [188, 4760]) in 2009 and 556 (95% C.I. [110, 2798]) in 2010, which was considerably lower than historical counts at the dam (between 14,532-46,785 in 1965-1971). Most tagged lamprey that did not pass the dam remained at the base of the dam at the end of the summer migration (63% in 2009 and 67% in 2010). Types of habitat most frequently used by lamprey downstream from the dam included the dam surface (wooden structures with crevices), interface zones between fast and slow water, and highway bridge pilings. The lamprey movement changed considerably between August and September, and the frequency of movements decreased sharply during this period. Tagged lamprey were detected using thermal refuges immediately downstream of the dam that were 0.4 to 2.8 C° colder than the mean river temperature at the dam, and this temperature differential increased as the season progressed. Lamprey may be seeking overwintering habitat associated with hyporheic exchange flows at the dam towards the end of the summer season after their display of heightened activity early in the summer. Ninety-five percent of the overall upstream migration took place during the first spring/summer period, and only small-scale upstream movements were observed during the winter and second spring/summer (4% and 1%, respectively). The rate of upstream migration (median) was the fastest during the initial migration phase and was 1.9 km/day (ranging from 0.3 to 11.0 km/day) for tagged lamprey released above Winchester Dam. During winter, 71% of the lamprey remained in the same location where they initiated holding. Multiple regression analysis indicated that the total upstream distance traveled by individual lamprey was most strongly related to presence/absence of Winchester Dam, relative tag size, and water temperature and photoperiod conditions at release. The presence of Winchester Dam, large relative tag size, and high water temperature / short photoperiod conditions at release significantly reduced upstream migration distance. Close

• 225. [Article] Measuring costs of sequestering carbon in forest stands with different management regimes in western Oregon

  This project was a part of larger work that compared major factors controlling patterns of carbon dynamics in two regions of the globe, the Pacific Northwest, USA and northwestern Russia. It was funded ...

  Citation × Citation Citation Abstract Copy Title: Measuring costs of sequestering carbon in forest stands with different management regimes in western Oregon Author: Zyrina, Olga A. This project was a part of larger work that compared major factors controlling patterns of carbon dynamics in two regions of the globe, the Pacific Northwest, USA and northwestern Russia. It was funded through the NASA foundation (grant # NAG5- 6242). Human economic activity is causing the release of pollutants such as carbon dioxide. The increased concentration of pollutants in the atmosphere is thought to cause greenhouse effect, in other words - the warming of the earth and lower atmosphere. Different methods are proposed to reduce concentration of greenhouse gases (GHG) in the atmosphere. Some involve development of more clean technologies. Some involve reductions in the use of fossil fuels. Another possibility is to store carbon (C) as live biomass. Plants use C for growth and development. Using forests to sequester C is one strategy for mitigating effects of GHG emissions. There are many methods in forestry to grow trees and produce wood products. Some of them include clearcutting, thinning, fertilizing, burning, and partial cutting. This project had three purposes. First, was to investigate the effect of a wide variety of silvicultural treatments on C storage and the economic value of harvested forest products. We measured economic value as soil expectation value. Second, was to use Data Envelopment Analysis to determine the efficient set of treatments, which make up the Production Possibility Frontier (PPF) in terms of C and economic value. Third, was to use the PPF to measure the marginal cost of carbon storage in moving from high SEV and relatively low C storage to lower SEV and relatively high C storage. C storage and timber harvest were simulated using the STANDCARB model for forest types common in north-western Oregon with two tree species, Douglas fir (Pseudotsuga menziesii) and Western hemlock (Tsuga heterophylla). Fifty silvicultural regimes were investigated. They included clearcutting with rotations of 50, 70, 90, 110, 130, and 150. Each of the six rotation ages had eight combinations of silvicultural treatments consisting of artificial and natural regeneration, growth enhancement (GE) and thinning. Two partial cutting regimes: group selection and single-tree selection were also used in the analysis. C storage was calculated for every output year of each model run as a sum of live, dead, and stable C. C storage for each silvicultural regime was measured as the average over five full rotations from the steady state portion of the run. The analysis showed that average C increases with rotation age from 335.99 MgC/ha with 50-year rotation with natural regeneration and thinning to 826.36 MgCIha with 150-year rotation with artificial regeneration and GE. The use of artificial regeneration compared to natural regeneration gave a 20-30 MgC/ha improvement for all regimes. The total harvest from thinning and clearcutting over the rotation period averaged for several runs varied from 505.34 m3/ha (with 50-year rotation no treatment) to 1782.24 m3/ha (with 150-year rotation with GE and thinning) The use of artificial compared to natural regeneration gave a 20-50 m3/ha increase in harvest for all regimes. SEV is the present value of net revenues from perpetually growing tree crops following the specified regime. It measures the economic value of each regime. Generally, SEV has a negative correlation with rotation length. Using a 3.5 percent real discount rate, the maximum SEV ($7904.3/hectare) was obtained from 50-year rotation with artificial regeneration, GE and thinning In contrast, SEV for 130-year rotation with artificial regeneration was only $446.68/hectare. Using Data Envelopment Analysis (OnFront software) we found that 8 of the 50 regimes investigated were efficient in their ability to store C and produce economic value. The efficient regimes included 50, 110, 130 and 150-year rotations with artificial regeneration, GE and thinning; 110, 130 and 150-year rotations with natural regeneration, GE and thinning, and the 150-year rotation with natural regeneration and GE. When regimes with GE were excluded, we found 7 efficient regimes: 50 and 150-year rotations with artificial regeneration and thinning, 50, 110, 130 and 150-year rotations with natural regeneration and thinning, and the 150-year rotation with natural regeneration. The marginal cost of C storage is the SEV lost per unit of C due to change in silvicultural regimes that results in increase of average C stored. Marginal cost analysis indicated that marginal cost values were similar for regimes with GE and without. As C storage increased, the marginal cost generally increased. The increase in C storage from 428 MgC/ha to 589 MgC/ha implied a marginal cost of $13.28IMgC. In case of increasing C storage from 683 MgC/ha to 802.7 MgC/ha, the marginal cost would increase to $32.79JMgC. Title: Measuring costs of sequestering carbon in forest stands with different management regimes in western Oregon Author: Zyrina, Olga A. This project was a part of larger work that compared major factors controlling patterns of carbon dynamics in two regions of the globe, the Pacific Northwest, USA and northwestern Russia. It was funded through the NASA foundation (grant # NAG5- 6242). Human economic activity is causing the release of pollutants such as carbon dioxide. The increased concentration of pollutants in the atmosphere is thought to cause greenhouse effect, in other words - the warming of the earth and lower atmosphere. Different methods are proposed to reduce concentration of greenhouse gases (GHG) in the atmosphere. Some involve development of more clean technologies. Some involve reductions in the use of fossil fuels. Another possibility is to store carbon (C) as live biomass. Plants use C for growth and development. Using forests to sequester C is one strategy for mitigating effects of GHG emissions. There are many methods in forestry to grow trees and produce wood products. Some of them include clearcutting, thinning, fertilizing, burning, and partial cutting. This project had three purposes. First, was to investigate the effect of a wide variety of silvicultural treatments on C storage and the economic value of harvested forest products. We measured economic value as soil expectation value. Second, was to use Data Envelopment Analysis to determine the efficient set of treatments, which make up the Production Possibility Frontier (PPF) in terms of C and economic value. Third, was to use the PPF to measure the marginal cost of carbon storage in moving from high SEV and relatively low C storage to lower SEV and relatively high C storage. C storage and timber harvest were simulated using the STANDCARB model for forest types common in north-western Oregon with two tree species, Douglas fir (Pseudotsuga menziesii) and Western hemlock (Tsuga heterophylla). Fifty silvicultural regimes were investigated. They included clearcutting with rotations of 50, 70, 90, 110, 130, and 150. Each of the six rotation ages had eight combinations of silvicultural treatments consisting of artificial and natural regeneration, growth enhancement (GE) and thinning. Two partial cutting regimes: group selection and single-tree selection were also used in the analysis. C storage was calculated for every output year of each model run as a sum of live, dead, and stable C. C storage for each silvicultural regime was measured as the average over five full rotations from the steady state portion of the run. The analysis showed that average C increases with rotation age from 335.99 MgC/ha with 50-year rotation with natural regeneration and thinning to 826.36 MgCIha with 150-year rotation with artificial regeneration and GE. The use of artificial regeneration compared to natural regeneration gave a 20-30 MgC/ha improvement for all regimes. The total harvest from thinning and clearcutting over the rotation period averaged for several runs varied from 505.34 m3/ha (with 50-year rotation no treatment) to 1782.24 m3/ha (with 150-year rotation with GE and thinning) The use of artificial compared to natural regeneration gave a 20-50 m3/ha increase in harvest for all regimes. SEV is the present value of net revenues from perpetually growing tree crops following the specified regime. It measures the economic value of each regime. Generally, SEV has a negative correlation with rotation length. Using a 3.5 percent real discount rate, the maximum SEV ($7904.3/hectare) was obtained from 50-year rotation with artificial regeneration, GE and thinning In contrast, SEV for 130-year rotation with artificial regeneration was only $446.68/hectare. Using Data Envelopment Analysis (OnFront software) we found that 8 of the 50 regimes investigated were efficient in their ability to store C and produce economic value. The efficient regimes included 50, 110, 130 and 150-year rotations with artificial regeneration, GE and thinning; 110, 130 and 150-year rotations with natural regeneration, GE and thinning, and the 150-year rotation with natural regeneration and GE. When regimes with GE were excluded, we found 7 efficient regimes: 50 and 150-year rotations with artificial regeneration and thinning, 50, 110, 130 and 150-year rotations with natural regeneration and thinning, and the 150-year rotation with natural regeneration. The marginal cost of C storage is the SEV lost per unit of C due to change in silvicultural regimes that results in increase of average C stored. Marginal cost analysis indicated that marginal cost values were similar for regimes with GE and without. As C storage increased, the marginal cost generally increased. The increase in C storage from 428 MgC/ha to 589 MgC/ha implied a marginal cost of $13.28IMgC. In case of increasing C storage from 683 MgC/ha to 802.7 MgC/ha, the marginal cost would increase to $32.79JMgC. Close

• 226. [Article] Double-crested Cormorants (Phalacrocorax auritus) and Brandt’s Cormorants (P. penicillatus) Breeding at East Sand Island in the Columbia River Estuary : Foraging Ecology, Colony Connectivity, and Overwinter Dispersal

  Double-crested cormorants (Phalacrocorax auritus) and Brandt’s cormorants (P. penicillatus) nest sympatrically in a large mixed-species colony on East Sand Island (ESI) in the Columbia River estuary. Ecological ...

  Citation × Citation Citation Abstract Copy Title: Double-crested Cormorants (Phalacrocorax auritus) and Brandt’s Cormorants (P. penicillatus) Breeding at East Sand Island in the Columbia River Estuary : Foraging Ecology, Colony Connectivity, and Overwinter Dispersal Author: Peck-Richardson, Adam Double-crested cormorants (Phalacrocorax auritus) and Brandt’s cormorants (P. penicillatus) nest sympatrically in a large mixed-species colony on East Sand Island (ESI) in the Columbia River estuary. Ecological theory predicts that such morphologically similar species will partition prey resources when faced with resource limitations. During the summer of 2014, I investigated local movements, foraging dive behavior, and foraging habitat selection by breeding adults of both cormorant species using GPS tags with integrated temperature and depth data-loggers (GPS-TDlog, Earth & Ocean Technologies). The overall foraging areas and core foraging areas (defined as the 95% and 50% kernel density estimates of dive locations, respectively) of double-crested cormorants were much larger and covered a broader range of estuarine habitats than those of Brandt’s cormorants. Only 26% and 27% of the overall and core foraging areas, respectively, for double-crested cormorants overlapped with those of Brandt’s cormorants. Most of the overall and core foraging areas of Brandt’s cormorants (59% and 89%, respectively) overlapped with those of double-crested cormorants, however. Within areas of overlap, Brandt’s cormorants tended to dive deeper (median depth = 6.48 m) than double-crested cormorants (median depth = 2.67 m), and selected dive locations where the water was deeper. After accounting for local water depth, Brandt’s cormorants utilized a deeper, more benthic portion of the water column than did double-crested cormorants. Our results indicate that species-specific patterns of foraging habitat utilization likely reflect past evolutionary divergence in foraging niche and evolved differences in behavioral and physiological adaptations, resulting in some partitioning of prey resources that would mitigate interspecific competition. Nevertheless, the substantial overlap in foraging habitat between the two cormorant species, particularly for Brandt’s cormorants, suggests that superabundant prey resources allow these two large and productive cormorant colonies to coexist on a single island near the mouth of the Columbia River. Annual consumption of millions of out-migrating juvenile salmonids (Oncorhynchus spp.), including smolts from populations listed under the U.S. Endangered Species Act, by double-crested cormorants nesting at ESI motivated natural resource managers to investigate potential management techniques to reduce cormorant predation by reducing the size of the breeding colony. To better understand potential dispersal of cormorants from the ESI colony due to management to reduce colony size, satellite transmitters were fitted on 83 double-crested cormorants captured on the ESI colony before egg-laying in 2013. Dispersal from ESI immediately following tagging was nearly ubiquitous, but temporary, and provided limited information on where cormorants might prospect for alternative nest sites if prevented from nesting on ESI. During this initial pre-nesting period, tagged cormorants were detected at colonies and roost sites as far from ESI as the Puget Sound region of coastal Washington; nevertheless, all but 4% of tagged cormorants returned to ESI within 2 weeks of being tagged. Following the subsequent breeding season, tagged cormorants staged at several nearby estuaries before migrating both north and south from ESI to overwinter in areas from British Columbia to northwestern Mexico; only 3% overwintered in the Columbia River estuary. Tracking data revealed substantial connectivity between the ESI colony and other colonies and regions within the range of the western North America population, suggesting the potential for widespread dispersal throughout the population’s breeding range if nesting habitat on ESI was reduced or eliminated. Dispersal did not extend across the Cascade-Sierra Divide, however; greater connectivity existed with estuary locations throughout the range and particularly with more proximate estuaries that served as post-breeding staging areas. Surprisingly low regional and colony connectivity was observed with the Oregon Coast, despite numerous active and historical colonies in that region, as well as proximity to the colony at ESI. The strong philopatry to ESI that nearly all tagged cormorants exhibited, however, suggests that few alternative nesting opportunities are as attractive for prospecting double-crested cormorants as the ESI colony site. Title: Double-crested Cormorants (Phalacrocorax auritus) and Brandt’s Cormorants (P. penicillatus) Breeding at East Sand Island in the Columbia River Estuary : Foraging Ecology, Colony Connectivity, and Overwinter Dispersal Author: Peck-Richardson, Adam Double-crested cormorants (Phalacrocorax auritus) and Brandt’s cormorants (P. penicillatus) nest sympatrically in a large mixed-species colony on East Sand Island (ESI) in the Columbia River estuary. Ecological theory predicts that such morphologically similar species will partition prey resources when faced with resource limitations. During the summer of 2014, I investigated local movements, foraging dive behavior, and foraging habitat selection by breeding adults of both cormorant species using GPS tags with integrated temperature and depth data-loggers (GPS-TDlog, Earth & Ocean Technologies). The overall foraging areas and core foraging areas (defined as the 95% and 50% kernel density estimates of dive locations, respectively) of double-crested cormorants were much larger and covered a broader range of estuarine habitats than those of Brandt’s cormorants. Only 26% and 27% of the overall and core foraging areas, respectively, for double-crested cormorants overlapped with those of Brandt’s cormorants. Most of the overall and core foraging areas of Brandt’s cormorants (59% and 89%, respectively) overlapped with those of double-crested cormorants, however. Within areas of overlap, Brandt’s cormorants tended to dive deeper (median depth = 6.48 m) than double-crested cormorants (median depth = 2.67 m), and selected dive locations where the water was deeper. After accounting for local water depth, Brandt’s cormorants utilized a deeper, more benthic portion of the water column than did double-crested cormorants. Our results indicate that species-specific patterns of foraging habitat utilization likely reflect past evolutionary divergence in foraging niche and evolved differences in behavioral and physiological adaptations, resulting in some partitioning of prey resources that would mitigate interspecific competition. Nevertheless, the substantial overlap in foraging habitat between the two cormorant species, particularly for Brandt’s cormorants, suggests that superabundant prey resources allow these two large and productive cormorant colonies to coexist on a single island near the mouth of the Columbia River. Annual consumption of millions of out-migrating juvenile salmonids (Oncorhynchus spp.), including smolts from populations listed under the U.S. Endangered Species Act, by double-crested cormorants nesting at ESI motivated natural resource managers to investigate potential management techniques to reduce cormorant predation by reducing the size of the breeding colony. To better understand potential dispersal of cormorants from the ESI colony due to management to reduce colony size, satellite transmitters were fitted on 83 double-crested cormorants captured on the ESI colony before egg-laying in 2013. Dispersal from ESI immediately following tagging was nearly ubiquitous, but temporary, and provided limited information on where cormorants might prospect for alternative nest sites if prevented from nesting on ESI. During this initial pre-nesting period, tagged cormorants were detected at colonies and roost sites as far from ESI as the Puget Sound region of coastal Washington; nevertheless, all but 4% of tagged cormorants returned to ESI within 2 weeks of being tagged. Following the subsequent breeding season, tagged cormorants staged at several nearby estuaries before migrating both north and south from ESI to overwinter in areas from British Columbia to northwestern Mexico; only 3% overwintered in the Columbia River estuary. Tracking data revealed substantial connectivity between the ESI colony and other colonies and regions within the range of the western North America population, suggesting the potential for widespread dispersal throughout the population’s breeding range if nesting habitat on ESI was reduced or eliminated. Dispersal did not extend across the Cascade-Sierra Divide, however; greater connectivity existed with estuary locations throughout the range and particularly with more proximate estuaries that served as post-breeding staging areas. Surprisingly low regional and colony connectivity was observed with the Oregon Coast, despite numerous active and historical colonies in that region, as well as proximity to the colony at ESI. The strong philopatry to ESI that nearly all tagged cormorants exhibited, however, suggests that few alternative nesting opportunities are as attractive for prospecting double-crested cormorants as the ESI colony site. Close

• 227. [Article] Debris flows in glaciated catchments : a case study on Mount Rainier, Washington

  Debris flows, which occur in mountain settings worldwide, have been particularly damaging in the glaciated basins flanking the stratovolcanoes in the Cascade Range of the northwestern United States. This ...

  Citation × Citation Citation Abstract Copy Title: Debris flows in glaciated catchments : a case study on Mount Rainier, Washington Author: Legg, Nicholas T. Debris flows, which occur in mountain settings worldwide, have been particularly damaging in the glaciated basins flanking the stratovolcanoes in the Cascade Range of the northwestern United States. This thesis contains two manuscripts that respectively investigate the (1) initiation processes of debris flows in these glaciated catchments, and (2) debris flow occurrence and its effect on valley bottoms over the last thousand years. In a 2006 storm, seven debris flows initiated from proglacial gullies of separate basins on the flanks of Mount Rainier. Gully heads at glacier termini and distributed collapse of gully walls imply that clear water was transformed to debris flow through progressive addition of sediment along gully lengths. In the first study, we analyze gully changes, reconstruct runoff conditions, and assess spatial distributions of debris flows to infer the processes and conditions necessary for debris flow initiation in glaciated catchments. Gully measurements suggest that sediment bulking requires steep gradients, abundant unstable material, and sufficient gully length. Reconstruction of runoff generated during the storm suggests that glaciers are important for generating the runoff necessary for debris flow initiation, particularly because infiltration capacities on glacial till covered surfaces well exceed measured rainfall rates. Runoff generation from glaciers and abundant loose debris at their termini explain why all debris flows in the storm initiated from proglacial areas. Proglacial areas that produced debris flows have steeper drainage networks with significantly higher elevations and lower drainage areas, suggesting that debris flows are associated with high elevation glaciers with relatively steep proglacial areas. This correlation reflects positive slope-elevation trends for the Mount Rainier volcano. An indirect effect of glacier change is thus the change in the distribution of ice-free slopes, which influence a basin’s debris flow potential. These findings have implications for projections of debris flow activity in basins experiencing glacier change. The second study uses a variety of dating techniques to reconstruct a chronology of debris flows in the Kautz Creek valley on the southwest flank of Mount Rainier (Washington). Dendrochronologic dating of growth disturbances combined with lichenometric techniques constrained five debris flow ages from 1712 to 1915 AD. We also estimated ages of three debris flows ranging in age from ca. 970 to 1661. Run-out distances served as a proxy for debris flow magnitude, and indicate that at least 11, 2, and 1 debris flow(s) have traveled at least 1, 3, and 5 km from the valley head, respectively since ca. 1650. Valley form reflects the frequency-magnitude relationship indicated by the chronology. In the upper, relatively steep valley, discrete debris flow snouts and secondary channels are abundant, suggesting a process of debris flow conveyance, channel plugging, and channel avulsion. The lower valley is characterized by relatively smooth surfaces, an absence of bouldery debris flow snouts, few secondary channels, and relatively old surface ages inferred from the presence of tephra layers. We infer that the lower valley is deposited on by relatively infrequent, large magnitude, low-yield strength debris flows like an event in 1947, which deposited wide, tabular lobes of debris outside of the main channel. Debris flows during the Little Ice Age (LIA) predominantly traveled no further than the upper valley. Stratigraphic evidence suggests that the main Kautz Creek channel was filled during the LIA, enhancing debris flow deposition on the valley surface and perhaps reducing run-out lengths. Diminished areas and gradients in front of glaciers during the LIA also likely contributed to decreased run-out lengths. These findings suggest that changes in debris flow source and depositional zones resulting from temperature and glacier cycles influence the magnitude and run-out distances of debris flows, and the dynamics of deposition in valley bottoms. Title: Debris flows in glaciated catchments : a case study on Mount Rainier, Washington Author: Legg, Nicholas T. Debris flows, which occur in mountain settings worldwide, have been particularly damaging in the glaciated basins flanking the stratovolcanoes in the Cascade Range of the northwestern United States. This thesis contains two manuscripts that respectively investigate the (1) initiation processes of debris flows in these glaciated catchments, and (2) debris flow occurrence and its effect on valley bottoms over the last thousand years. In a 2006 storm, seven debris flows initiated from proglacial gullies of separate basins on the flanks of Mount Rainier. Gully heads at glacier termini and distributed collapse of gully walls imply that clear water was transformed to debris flow through progressive addition of sediment along gully lengths. In the first study, we analyze gully changes, reconstruct runoff conditions, and assess spatial distributions of debris flows to infer the processes and conditions necessary for debris flow initiation in glaciated catchments. Gully measurements suggest that sediment bulking requires steep gradients, abundant unstable material, and sufficient gully length. Reconstruction of runoff generated during the storm suggests that glaciers are important for generating the runoff necessary for debris flow initiation, particularly because infiltration capacities on glacial till covered surfaces well exceed measured rainfall rates. Runoff generation from glaciers and abundant loose debris at their termini explain why all debris flows in the storm initiated from proglacial areas. Proglacial areas that produced debris flows have steeper drainage networks with significantly higher elevations and lower drainage areas, suggesting that debris flows are associated with high elevation glaciers with relatively steep proglacial areas. This correlation reflects positive slope-elevation trends for the Mount Rainier volcano. An indirect effect of glacier change is thus the change in the distribution of ice-free slopes, which influence a basin’s debris flow potential. These findings have implications for projections of debris flow activity in basins experiencing glacier change. The second study uses a variety of dating techniques to reconstruct a chronology of debris flows in the Kautz Creek valley on the southwest flank of Mount Rainier (Washington). Dendrochronologic dating of growth disturbances combined with lichenometric techniques constrained five debris flow ages from 1712 to 1915 AD. We also estimated ages of three debris flows ranging in age from ca. 970 to 1661. Run-out distances served as a proxy for debris flow magnitude, and indicate that at least 11, 2, and 1 debris flow(s) have traveled at least 1, 3, and 5 km from the valley head, respectively since ca. 1650. Valley form reflects the frequency-magnitude relationship indicated by the chronology. In the upper, relatively steep valley, discrete debris flow snouts and secondary channels are abundant, suggesting a process of debris flow conveyance, channel plugging, and channel avulsion. The lower valley is characterized by relatively smooth surfaces, an absence of bouldery debris flow snouts, few secondary channels, and relatively old surface ages inferred from the presence of tephra layers. We infer that the lower valley is deposited on by relatively infrequent, large magnitude, low-yield strength debris flows like an event in 1947, which deposited wide, tabular lobes of debris outside of the main channel. Debris flows during the Little Ice Age (LIA) predominantly traveled no further than the upper valley. Stratigraphic evidence suggests that the main Kautz Creek channel was filled during the LIA, enhancing debris flow deposition on the valley surface and perhaps reducing run-out lengths. Diminished areas and gradients in front of glaciers during the LIA also likely contributed to decreased run-out lengths. These findings suggest that changes in debris flow source and depositional zones resulting from temperature and glacier cycles influence the magnitude and run-out distances of debris flows, and the dynamics of deposition in valley bottoms. Close

• 228. [Article] Multi-objective Optimization of Reservoir Operation Under Uncertainty with Robust and Flexible Decision Variables

  Optimization of reservoir operation is involves various competing objectives for a scarce resource (water). To find the optimal operation of reservoirs, it is essential to consider multiple objectives ...

  Citation × Citation Citation Abstract Copy Title: Multi-objective Optimization of Reservoir Operation Under Uncertainty with Robust and Flexible Decision Variables Author: Hosseini, Parnian Optimization of reservoir operation is involves various competing objectives for a scarce resource (water). To find the optimal operation of reservoirs, it is essential to consider multiple objectives simultaneously. There are various sources of uncertainty associated with the reservoir operation problem that should be considered as well. The overarching goal of this research is to develop a framework for finding flexible and reliable solutions to the reservoir operation problem with competing objectives. Because some sources of uncertainty are not well quantified, providing flexible decision variables lets the decision maker choose accordingly from a range of options knowing that all the flexible decision variables are feasible with a specified probability of failure and that are relatively optimal. To accomplish this goal, each flexible decision variable is represented by a random variable within a specific range instead of a single deterministic decision variable. An additional objective is added to the optimization problem, in order to maximize the flexibility of decision variables. The proposed methodology is tested for two mathematical test problems and the operation of the Grand Coulee reservoir, which is located on the Columbia River in the Northwestern United States. The Stochastic Collocation (SC) method is used to sample the random variables and approximate the expected values of the objectives. For the Grand Coulee reservoir, the decision variables are the daily turbine outflows. The first objective of the optimization is to minimize the forebay elevation deviation at the end of the optimization period. The second objective is to maximize the revenue from the hydropower production. The results show that the proposed methodology could find some flexible decision variables with 45% coefficient of variation. The corresponding expected objectives have less than 20% deterioration from the deterministic Pareto solutions. However, the number of function evaluations increases exponentially with the number of decision variables. Therefore, this methodology is suggested for problems with a few decision variables. For finding flexible decision variables in problems with many decision variables, a dimension reduction method called Karhunen Loeve (KL) expansion is implemented in the optimization problem. By extracting useful information from the decision variables, the decision space can be represented with merely a few random variables using a set of deterministic decision variables. The results show that three random variables are sufficient to generate decision variable realizations which have mean and variance less than 1% and 5% different from the original decision variable realizations, respectively. The proposed methodology is capable of efficiently finding flexible decision variables that lead to expected objective values close to the Pareto deterministic solutions. To force the generated decision variable realizations to stay within the feasible bounds and therefore reduce the number of constraints that need to be checked, the data is transformed to be within bounds first, and then the KL-expansion is performed. Using the transformed data decreases the computational time but the decrease in computational time is not significant. The inflow uncertainty is also considered as the only source of input uncertainty. Forecast inflow ensembles can be used as the source of inflow uncertainty. However in this study due to lack of information, historical inflows are used instead. The inflow uncertainties are represented using the KL-expansion. Robust optimization is performed by optimizing the weighted sum of the expectation and standard deviation of the objective due to uncertain inflows. The weights in the robust objective formulation can be changed based on the decision maker’s preference of robustness versus performance. Finally, the combined framework to find robust and flexible decision variables is tested on a reservoir operation problem and the results were compared to the deterministic case. Title: Multi-objective Optimization of Reservoir Operation Under Uncertainty with Robust and Flexible Decision Variables Author: Hosseini, Parnian Optimization of reservoir operation is involves various competing objectives for a scarce resource (water). To find the optimal operation of reservoirs, it is essential to consider multiple objectives simultaneously. There are various sources of uncertainty associated with the reservoir operation problem that should be considered as well. The overarching goal of this research is to develop a framework for finding flexible and reliable solutions to the reservoir operation problem with competing objectives. Because some sources of uncertainty are not well quantified, providing flexible decision variables lets the decision maker choose accordingly from a range of options knowing that all the flexible decision variables are feasible with a specified probability of failure and that are relatively optimal. To accomplish this goal, each flexible decision variable is represented by a random variable within a specific range instead of a single deterministic decision variable. An additional objective is added to the optimization problem, in order to maximize the flexibility of decision variables. The proposed methodology is tested for two mathematical test problems and the operation of the Grand Coulee reservoir, which is located on the Columbia River in the Northwestern United States. The Stochastic Collocation (SC) method is used to sample the random variables and approximate the expected values of the objectives. For the Grand Coulee reservoir, the decision variables are the daily turbine outflows. The first objective of the optimization is to minimize the forebay elevation deviation at the end of the optimization period. The second objective is to maximize the revenue from the hydropower production. The results show that the proposed methodology could find some flexible decision variables with 45% coefficient of variation. The corresponding expected objectives have less than 20% deterioration from the deterministic Pareto solutions. However, the number of function evaluations increases exponentially with the number of decision variables. Therefore, this methodology is suggested for problems with a few decision variables. For finding flexible decision variables in problems with many decision variables, a dimension reduction method called Karhunen Loeve (KL) expansion is implemented in the optimization problem. By extracting useful information from the decision variables, the decision space can be represented with merely a few random variables using a set of deterministic decision variables. The results show that three random variables are sufficient to generate decision variable realizations which have mean and variance less than 1% and 5% different from the original decision variable realizations, respectively. The proposed methodology is capable of efficiently finding flexible decision variables that lead to expected objective values close to the Pareto deterministic solutions. To force the generated decision variable realizations to stay within the feasible bounds and therefore reduce the number of constraints that need to be checked, the data is transformed to be within bounds first, and then the KL-expansion is performed. Using the transformed data decreases the computational time but the decrease in computational time is not significant. The inflow uncertainty is also considered as the only source of input uncertainty. Forecast inflow ensembles can be used as the source of inflow uncertainty. However in this study due to lack of information, historical inflows are used instead. The inflow uncertainties are represented using the KL-expansion. Robust optimization is performed by optimizing the weighted sum of the expectation and standard deviation of the objective due to uncertain inflows. The weights in the robust objective formulation can be changed based on the decision maker’s preference of robustness versus performance. Finally, the combined framework to find robust and flexible decision variables is tested on a reservoir operation problem and the results were compared to the deterministic case. Close

• 229. [Article] Drought, dispersal, and community dynamics in arid-land streams

  Understanding the mechanisms that regulate local species diversity and community structure is a perennial goal of ecology. Local community structure can be viewed as the result of numerous local and regional ...

  Citation × Citation Citation Abstract Copy Title: Drought, dispersal, and community dynamics in arid-land streams Author: Bogan, Michael T. Understanding the mechanisms that regulate local species diversity and community structure is a perennial goal of ecology. Local community structure can be viewed as the result of numerous local and regional processes; these processes act as filters that reduce the regional species pool down to the observed local community. In stream ecosystems, the natural flow regime (including the timing, magnitude, and duration of high and low flow events) is widely recognized as a primary regulator of local diversity and community composition. This is especially true in aridland streams, where low- and zero-flow events can occur frequently and for extended periods of time (months to years). Additionally, wetted habitat patches in arid-land stream networks are often fragmented within and among stream networks. Thus dispersal between isolated aquatic patches may also play a large role in regulating local communities. In my dissertation, I explored the roles that drought, dispersal, and local habitat factors play in structuring arid-land stream communities. I examined the impact of flow permanence and seasonal variation in flow and other abiotic factors on aquatic communities at both fine spatial scales over a long time period (8 years; Chapter 2) and at a broad spatial scale over a shorter time period (1-2 years; Chapter 4). Additionally, I quantified aquatic invertebrate aerial dispersal over moderate spatial scales (≤ 0.5 km) by conducting a colonization experiment using artificial stream pools placed along and inland from two arid-land streams (Chapter 4). Finally, I examined the roles of spatial isolation, microhabitat type, and local abiotic and biotic factors in structuring aquatic communities in freshwater oases scattered across one of the most arid regions of North America, the southern Sonoran Desert (Chapter 5). In Chapter 2, I found that severe drought caused an unprecedented drying event in isolated perennial stream pools, and that several additional drying events occurred over the following four years. This transition to intermittent flow caused the extirpation of several large, long-lived species with low dispersal abilities (including the top predator) and drove the local community into an alternative state. In the colonization experiment described in Chapter 3, I found that several arid-land stream invertebrate taxa disperse widely and frequently. The widespread dispersers identified by this experiment included several of the earliest colonist taxa observed following the severe drought described in Chapter 2. Other taxa, though, only dispersed overland after receiving an environmental cue (rainfall) or preferentially dispersed along stream corridors. In Chapter 4, where I examined invertebrate community structure across a large network of well-connected intermittent and perennial reaches, I found low diversity in intermittent reaches, regardless of their connectivity to diverse upstream perennial reaches. These species-poor, intermittent communities were composed of a unique suite of species with lifehistory adaptations that conferred desiccation resistance, including extended egg and larval diapause stages. The short flow duration of intermittent reaches (<100 days) likely precluded upstream perennial taxa from establishing populations in downstream intermittent reaches before drying occurred, while the relative predictability of flow timing (Dec-Apr) likely allowed for a small number of species to develop appropriate life-history traits (e.g., diapause stage, rapid development time) to exploit these temporally-fleeting habitats. In Chapter 5, I found over 220 species of aquatic animals (including ≥ 5 undescribed species) in the 19 desert oases that were sampled across the southern Sonoran Desert. Local community composition in these oases was strongly driven by microhabitat type. Additionally, native aquatic species richness and abundance in these oases were significantly reduced by the introduction of tilapia, an exotic fish species. The threats to arid-land streams presented by increased drought severity, anthropogenic water withdrawals, and local habitat degradation (e.g., introduced species, unmanaged recreational use) are grave across the southwestern US and northwestern Mexico. I hope that in addition to furthering our understanding of ecological processes in arid-land streams, this dissertation makes a small contribution towards the efforts to preserve these habitats. Title: Drought, dispersal, and community dynamics in arid-land streams Author: Bogan, Michael T. Understanding the mechanisms that regulate local species diversity and community structure is a perennial goal of ecology. Local community structure can be viewed as the result of numerous local and regional processes; these processes act as filters that reduce the regional species pool down to the observed local community. In stream ecosystems, the natural flow regime (including the timing, magnitude, and duration of high and low flow events) is widely recognized as a primary regulator of local diversity and community composition. This is especially true in aridland streams, where low- and zero-flow events can occur frequently and for extended periods of time (months to years). Additionally, wetted habitat patches in arid-land stream networks are often fragmented within and among stream networks. Thus dispersal between isolated aquatic patches may also play a large role in regulating local communities. In my dissertation, I explored the roles that drought, dispersal, and local habitat factors play in structuring arid-land stream communities. I examined the impact of flow permanence and seasonal variation in flow and other abiotic factors on aquatic communities at both fine spatial scales over a long time period (8 years; Chapter 2) and at a broad spatial scale over a shorter time period (1-2 years; Chapter 4). Additionally, I quantified aquatic invertebrate aerial dispersal over moderate spatial scales (≤ 0.5 km) by conducting a colonization experiment using artificial stream pools placed along and inland from two arid-land streams (Chapter 4). Finally, I examined the roles of spatial isolation, microhabitat type, and local abiotic and biotic factors in structuring aquatic communities in freshwater oases scattered across one of the most arid regions of North America, the southern Sonoran Desert (Chapter 5). In Chapter 2, I found that severe drought caused an unprecedented drying event in isolated perennial stream pools, and that several additional drying events occurred over the following four years. This transition to intermittent flow caused the extirpation of several large, long-lived species with low dispersal abilities (including the top predator) and drove the local community into an alternative state. In the colonization experiment described in Chapter 3, I found that several arid-land stream invertebrate taxa disperse widely and frequently. The widespread dispersers identified by this experiment included several of the earliest colonist taxa observed following the severe drought described in Chapter 2. Other taxa, though, only dispersed overland after receiving an environmental cue (rainfall) or preferentially dispersed along stream corridors. In Chapter 4, where I examined invertebrate community structure across a large network of well-connected intermittent and perennial reaches, I found low diversity in intermittent reaches, regardless of their connectivity to diverse upstream perennial reaches. These species-poor, intermittent communities were composed of a unique suite of species with lifehistory adaptations that conferred desiccation resistance, including extended egg and larval diapause stages. The short flow duration of intermittent reaches (<100 days) likely precluded upstream perennial taxa from establishing populations in downstream intermittent reaches before drying occurred, while the relative predictability of flow timing (Dec-Apr) likely allowed for a small number of species to develop appropriate life-history traits (e.g., diapause stage, rapid development time) to exploit these temporally-fleeting habitats. In Chapter 5, I found over 220 species of aquatic animals (including ≥ 5 undescribed species) in the 19 desert oases that were sampled across the southern Sonoran Desert. Local community composition in these oases was strongly driven by microhabitat type. Additionally, native aquatic species richness and abundance in these oases were significantly reduced by the introduction of tilapia, an exotic fish species. The threats to arid-land streams presented by increased drought severity, anthropogenic water withdrawals, and local habitat degradation (e.g., introduced species, unmanaged recreational use) are grave across the southwestern US and northwestern Mexico. I hope that in addition to furthering our understanding of ecological processes in arid-land streams, this dissertation makes a small contribution towards the efforts to preserve these habitats. Close