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• 3151. [Article] Augmenting and interpreting ice core greenhouse gas records

  The three studies that comprise this dissertation seek to answer significant questions in paleoclimatology through unconventional applications of ice core greenhouse gas data. These studies involve different ...

  Citation × Citation Citation Abstract Copy Title: Augmenting and interpreting ice core greenhouse gas records Author: Rosen, Julia L The three studies that comprise this dissertation seek to answer significant questions in paleoclimatology through unconventional applications of ice core greenhouse gas data. These studies involve different gases and span the interval of time between the Last Glacial Maximum and the Industrial Revolution, but are united by their nontraditional use of greenhouse gases and their attempt to realize the potential for greenhouse gases to reveal important information about Earth’s climate. Ever since their discovery, the abrupt climate changes of the last glacial period known as Dansgaard-Oeschger (D-O) events have proved challenging to explain. The dominant hypothesis involves periodic freshwater discharges into the North Atlantic, which may regulate the strength of the Meridional Overturning Circulation (MOC) and its role in transporting heat to high latitudes. These events were not restricted to the North Atlantic, and can also be recognized in paleoclimate archives around the world. However, numerous uncertainties surrounding the mechanism behind D-O events remain, including how they are communicated to low latitudes and whether other hypotheses can be definitively ruled out. To constrain the mechanism behind abrupt climate changes, we investigate the phasing of climate changes in high- and low-latitude regions at the Bølling Transition, the penultimate abrupt warming event of the last glacial period. We use methane and the ¹⁵N/¹⁴N ratio of N₂ from the North Greenland Eemian (NEEM) ice core, which serve as proxies for tropical climate and Greenland temperature, respectively. We find that these gases change synchronously in the ice core record, and use a firn air model together with a Monte Carlo approach to constrain the phase lag to within several decades. Our results indicate that the mechanism behind the Bølling Transition was capable of rapidly transmitting the climate signal across the planet in a matter of years, and must therefore involve components of the climate system that are suitably reactive. The glacial-interglacial change in atmospheric methane concentrations revealed in ice core records has spurred a decade of debate about its cause. The most likely explanations involve dramatic changes in methane emissions, which originate from both high- and low-latitude wetlands. One method of investigating the changing latitudinal distribution of methane sources is to quantify the difference in methane concentrations between Greenland and Antarctica, which changes in proportion to the fraction of methane produced at high northern latitudes. Previous attempts to determine the methane interpolar difference (IPD) abound, but many have been hampered by complications in synchronizing bipolar ice core records and analytical uncertainties. We present the first continuous estimate of the methane IPD across the termination using high-resolution methane data from the NEEM and West Antarctic Ice Sheet (WAIS) Divide ice cores. Our results reveal the dominant role of tropical sources in driving abrupt changes in atmospheric methane concentrations, and show that boreal methane sources were surprisingly insensitive to dramatic climate changes. We hypothesize that changes in Northern Hemisphere snow and ice cover exerted strong control over tropical methane emissions, while gradually increasing solar insolation and land area allowed boreal sources to grow during the termination. We also investigate the IPD across the major climate transitions of the termination, and during four centennial-scale methane variations, and find opposing trends in boreal and tropical source strengths during these transient events. We propose that temporary decoupling of the locus of interhemispheric mixing, the position of the Intertropical Convergence Zone, and tropical precipitation may explain these results. Atmospheric concentrations of nitrous oxide (N₂O) have risen by ~20% from preindustrial to modern times, but the cause of this increase is not fully understood. The change has been previously attributed to various agricultural activities which perturb microbial processes in soils, but exactly how remains an outstanding question with important implications for future mitigation of N₂O emissions. We present the first measurements of the isotopomers of tropospheric N₂O over the interval from 1450 to 1920 CE. Our results confirm that the preindustrial atmosphere was enriched in all isotopes relative to the modern atmosphere. Furthermore, we estimate that the net anthropogenic source of nitrous oxide must be depleted in all heavy isotopes and have a strong site preference, consistent with a strong role for agricultural emissions and characteristic of N₂O derived from nitrification. We also find a large oscillation in the site preference of the ¹⁵N in N₂O during the Little Ice Age between 1500 and 1700 CE. We hypothesize that this excursion may be due to changing climate conditions that led to an increase in the amount of N₂O produced by nitrification vs. denitrification. Title: Augmenting and interpreting ice core greenhouse gas records Author: Rosen, Julia L The three studies that comprise this dissertation seek to answer significant questions in paleoclimatology through unconventional applications of ice core greenhouse gas data. These studies involve different gases and span the interval of time between the Last Glacial Maximum and the Industrial Revolution, but are united by their nontraditional use of greenhouse gases and their attempt to realize the potential for greenhouse gases to reveal important information about Earth’s climate. Ever since their discovery, the abrupt climate changes of the last glacial period known as Dansgaard-Oeschger (D-O) events have proved challenging to explain. The dominant hypothesis involves periodic freshwater discharges into the North Atlantic, which may regulate the strength of the Meridional Overturning Circulation (MOC) and its role in transporting heat to high latitudes. These events were not restricted to the North Atlantic, and can also be recognized in paleoclimate archives around the world. However, numerous uncertainties surrounding the mechanism behind D-O events remain, including how they are communicated to low latitudes and whether other hypotheses can be definitively ruled out. To constrain the mechanism behind abrupt climate changes, we investigate the phasing of climate changes in high- and low-latitude regions at the Bølling Transition, the penultimate abrupt warming event of the last glacial period. We use methane and the ¹⁵N/¹⁴N ratio of N₂ from the North Greenland Eemian (NEEM) ice core, which serve as proxies for tropical climate and Greenland temperature, respectively. We find that these gases change synchronously in the ice core record, and use a firn air model together with a Monte Carlo approach to constrain the phase lag to within several decades. Our results indicate that the mechanism behind the Bølling Transition was capable of rapidly transmitting the climate signal across the planet in a matter of years, and must therefore involve components of the climate system that are suitably reactive. The glacial-interglacial change in atmospheric methane concentrations revealed in ice core records has spurred a decade of debate about its cause. The most likely explanations involve dramatic changes in methane emissions, which originate from both high- and low-latitude wetlands. One method of investigating the changing latitudinal distribution of methane sources is to quantify the difference in methane concentrations between Greenland and Antarctica, which changes in proportion to the fraction of methane produced at high northern latitudes. Previous attempts to determine the methane interpolar difference (IPD) abound, but many have been hampered by complications in synchronizing bipolar ice core records and analytical uncertainties. We present the first continuous estimate of the methane IPD across the termination using high-resolution methane data from the NEEM and West Antarctic Ice Sheet (WAIS) Divide ice cores. Our results reveal the dominant role of tropical sources in driving abrupt changes in atmospheric methane concentrations, and show that boreal methane sources were surprisingly insensitive to dramatic climate changes. We hypothesize that changes in Northern Hemisphere snow and ice cover exerted strong control over tropical methane emissions, while gradually increasing solar insolation and land area allowed boreal sources to grow during the termination. We also investigate the IPD across the major climate transitions of the termination, and during four centennial-scale methane variations, and find opposing trends in boreal and tropical source strengths during these transient events. We propose that temporary decoupling of the locus of interhemispheric mixing, the position of the Intertropical Convergence Zone, and tropical precipitation may explain these results. Atmospheric concentrations of nitrous oxide (N₂O) have risen by ~20% from preindustrial to modern times, but the cause of this increase is not fully understood. The change has been previously attributed to various agricultural activities which perturb microbial processes in soils, but exactly how remains an outstanding question with important implications for future mitigation of N₂O emissions. We present the first measurements of the isotopomers of tropospheric N₂O over the interval from 1450 to 1920 CE. Our results confirm that the preindustrial atmosphere was enriched in all isotopes relative to the modern atmosphere. Furthermore, we estimate that the net anthropogenic source of nitrous oxide must be depleted in all heavy isotopes and have a strong site preference, consistent with a strong role for agricultural emissions and characteristic of N₂O derived from nitrification. We also find a large oscillation in the site preference of the ¹⁵N in N₂O during the Little Ice Age between 1500 and 1700 CE. We hypothesize that this excursion may be due to changing climate conditions that led to an increase in the amount of N₂O produced by nitrification vs. denitrification. Close

• 3152. [Article] Novel methods for crop load management of pear cultivars in the Pacific Northwest

  Novel approaches to crop load management of pear orchards in the Pacific Northwest (PNW) are necessary, but will need to vary according to the unique vegetative and reproductive growth habits of the cultivar. ...

  Citation × Citation Citation Abstract Copy Title: Novel methods for crop load management of pear cultivars in the Pacific Northwest Author: Arrington, Matthew A. Novel approaches to crop load management of pear orchards in the Pacific Northwest (PNW) are necessary, but will need to vary according to the unique vegetative and reproductive growth habits of the cultivar. 'D'Anjou' is vigorous and non-precocious; thus, strategies to limit vigor and induce early fruiting are required. In contrast, 'Bartlett' possesses a high fruit-setting efficiency and, consequently, is prone to over-setting fruit. Thus, crop reduction is necessary to achieve marketable fruit size, but hand thinning is time-consuming and costly. Two methods were investigated to resolve these issues: Root pruning of 'd'Anjou' pear trees and, chemical thinning of 'Bartlett' pears using abscisic acid (ABA). Root pruning was imposed on one or both sides of the tree row and compared to an untreated control plot at two sites: Moderate-density, 6th leaf 'd'Anjou'/OH x F 87; and, high-density, 4th leaf 'd'Anjou'/OH x F 87. Root pruning two-sides of the tree row consistently reduced shoot growth and the effects were partially dependent on tree age at the time of root pruning. Return bloom was positively affected by root pruning, but fruit weight was often reduced. Reduced fruit weight was not associated with mid-season water or nutrient deficits. Yield and yield efficiency the year following double-sided root pruning were improved with the greatest response occurring in the younger orchard (i.e., ~70% yield increase over control plots). Root pruning is a viable strategy to reduce vigor and improve precocity in high-density 'd'Anjou' plantings when performed in the 3rd or 4th year after planting. Thinning efficacy of abscisic acid (ABA) applied to 'Bartlett' pear trees, between petal fall and 12mm fruit size, was inconsistent. Among four trials, ABA produced a rate-responsive, transient reduction in stomatal conductance and net photosynthesis (Pn) of ~ 80% to 95% within hours of application, the effect lasted one to two days. By day three, Pn returned to ~80% of control plots and was fully recovered by 7-10 days after application. Thinning was best achieved at 100-125 ppm ABA. Higher rates caused greater fruitlet abscission but rates exceeding 400 ppm resulted in phytotoxicity and leaf abscission. In field trials, good thinning was observed in years when low natural light (i.e., cloudy conditions) occurred during the week immediately succeeding ABA applications. Only a few days of low light appeared necessary to elicit ABA-induced fruit abscission. To test the additive effect of shade on ABA-induced thinning, an experiment was designed to expose whole canopies to one of three levels of shade (0%, 44%, or 77%) and two levels of ABA (0 or 125 ppm). Shade houses were erected within hours of ABA application (~petal fall) and were left in place for 15 days. Both ABA and shade affected fruit abscission, but 44% shade did not significantly reduce fruit set compared to control plots. Photosynthetic active radiation (PAR) was reduced relative to the intensity of shade, but Pn was not. Moderate shade (i.e., 44%) led to only minor reductions of Pn, while 77% shade reduced Pn by 50% to 75% for the duration of the treatment period. ABA-induced thinning was not significantly improved by the addition of shade; however, two days of non-forecasted, cloudy conditions (i.e., low light) within the first week of the experiment invalidated comparisons to a true control (i.e., 0% shade). Given the short-term Pn limitation induced by ABA, in combination with the high carbon reserves of pear trees, ABA application may not be consistent enough to warrant commercial application. Title: Novel methods for crop load management of pear cultivars in the Pacific Northwest Author: Arrington, Matthew A. Novel approaches to crop load management of pear orchards in the Pacific Northwest (PNW) are necessary, but will need to vary according to the unique vegetative and reproductive growth habits of the cultivar. 'D'Anjou' is vigorous and non-precocious; thus, strategies to limit vigor and induce early fruiting are required. In contrast, 'Bartlett' possesses a high fruit-setting efficiency and, consequently, is prone to over-setting fruit. Thus, crop reduction is necessary to achieve marketable fruit size, but hand thinning is time-consuming and costly. Two methods were investigated to resolve these issues: Root pruning of 'd'Anjou' pear trees and, chemical thinning of 'Bartlett' pears using abscisic acid (ABA). Root pruning was imposed on one or both sides of the tree row and compared to an untreated control plot at two sites: Moderate-density, 6th leaf 'd'Anjou'/OH x F 87; and, high-density, 4th leaf 'd'Anjou'/OH x F 87. Root pruning two-sides of the tree row consistently reduced shoot growth and the effects were partially dependent on tree age at the time of root pruning. Return bloom was positively affected by root pruning, but fruit weight was often reduced. Reduced fruit weight was not associated with mid-season water or nutrient deficits. Yield and yield efficiency the year following double-sided root pruning were improved with the greatest response occurring in the younger orchard (i.e., ~70% yield increase over control plots). Root pruning is a viable strategy to reduce vigor and improve precocity in high-density 'd'Anjou' plantings when performed in the 3rd or 4th year after planting. Thinning efficacy of abscisic acid (ABA) applied to 'Bartlett' pear trees, between petal fall and 12mm fruit size, was inconsistent. Among four trials, ABA produced a rate-responsive, transient reduction in stomatal conductance and net photosynthesis (Pn) of ~ 80% to 95% within hours of application, the effect lasted one to two days. By day three, Pn returned to ~80% of control plots and was fully recovered by 7-10 days after application. Thinning was best achieved at 100-125 ppm ABA. Higher rates caused greater fruitlet abscission but rates exceeding 400 ppm resulted in phytotoxicity and leaf abscission. In field trials, good thinning was observed in years when low natural light (i.e., cloudy conditions) occurred during the week immediately succeeding ABA applications. Only a few days of low light appeared necessary to elicit ABA-induced fruit abscission. To test the additive effect of shade on ABA-induced thinning, an experiment was designed to expose whole canopies to one of three levels of shade (0%, 44%, or 77%) and two levels of ABA (0 or 125 ppm). Shade houses were erected within hours of ABA application (~petal fall) and were left in place for 15 days. Both ABA and shade affected fruit abscission, but 44% shade did not significantly reduce fruit set compared to control plots. Photosynthetic active radiation (PAR) was reduced relative to the intensity of shade, but Pn was not. Moderate shade (i.e., 44%) led to only minor reductions of Pn, while 77% shade reduced Pn by 50% to 75% for the duration of the treatment period. ABA-induced thinning was not significantly improved by the addition of shade; however, two days of non-forecasted, cloudy conditions (i.e., low light) within the first week of the experiment invalidated comparisons to a true control (i.e., 0% shade). Given the short-term Pn limitation induced by ABA, in combination with the high carbon reserves of pear trees, ABA application may not be consistent enough to warrant commercial application. Close

• 3153. [Article] Photo-enhanced Toxicity of Oil Constituents and Corexit 9500 to Gulf of Mexico Marine Organisms

  Significant inputs of hydrocarbons are continually released into the environment from anthropogenic and natural sources. Some of the most toxic hydrocarbon compounds are polycyclic aromatic hydrocarbons. ...

  Citation × Citation Citation Abstract Copy Title: Photo-enhanced Toxicity of Oil Constituents and Corexit 9500 to Gulf of Mexico Marine Organisms Author: Finch, Bryson E. Significant inputs of hydrocarbons are continually released into the environment from anthropogenic and natural sources. Some of the most toxic hydrocarbon compounds are polycyclic aromatic hydrocarbons. Polycyclic aromatic hydrocarbons are known for their ability to absorb ultraviolet light and enhance toxicity. Generally, PAHs exert their toxicity via narcosis but UV-absorbing PAHs can become photosensitized and significantly exacerbate toxic effects. During crude oil spills, PAHs are released in large amounts that have potential for narcotic and phototoxic effects on aquatic organisms. As a result of the Deepwater Horizon oil spill, effort was placed on quantifying toxic effects of crude oils and oil constituents for aquatic organisms. The following studies attempted to characterize narcotic and phototoxic effects that may have occurred during the Deepwater Horizon incident; however, the results of this research are equally applicable to any PAH exposure scenario. The objectives of the following studies were to: 1) identify susceptible stages of Gulf of Mexico organisms to the photo-enhanced toxicity of PAHs, 2) determine the importance of UV intensity and exposure duration on phototoxicity, 3) determine the effect of alkylation on the phototoxic potency of PAHs, 4) validate the assumption of additivity for phototoxic PAHs mixtures, 5) evaluate the potential for narcotic toxicity and phototoxicity of fresh and weathered Macondo crude oils released from the Deepwater Horizon, and 6) assess the potential for ongoing oil phototoxicity at field sites in the Gulf of Mexico. Model organisms used in studies included the mysid shrimp (Americamysis bahia), inland silverside (Menidia beryllina), sheepshead minnow (Cyprinodon variegatus), and Gulf killifish (Fundulus grandis). Studies demonstrated that organism sensitivity to phototoxicity of PAHs decreased with organism age and increasing pigmentation. Photo-enhanced toxicity was, to some extent, dependent on the degree of organism pigmentation. Generally, high-intensity short-duration UV treatments resulted in greater toxicity than low-intensity long-duration UV treatments at similar UV doses. Fresh Macondo crude oil was more toxic than weathered crude oils, both in the presence and absence of UV light. Differences in toxicity between fresh and weathered crude oils were primarily attributed to the lighter mono and di-aromatic hydrocarbons in fresh crude oils. Phototoxic PAH concentrations were relatively similar among fresh and weathered crude oils, suggesting recalcitrance to oil weathering processes. The addition of Corexit 9500, an oil-dispersant used during the Deepwater Horizon oil spill, to crude oil in laboratory experiments increased toxicity compared to tests conducted with crude oil alone. It is anticipated that this enhanced response resulted from the increased concentrations of phototoxic and narcotic PAHs in water-accommodated fractions and the inherent toxicity of Corexit 9500. Weathered crude oil present in previously heavily-oiled Barataria Bay, LA field sites was found to pose little or no phototoxic risk in ambient environmental conditions four years after the Deepwater Horizon oil spill. Water-accommodated fractions of field-collected oil suggest slight phototoxic potential to mysid shrimp in the laboratory in highly transparent artificial seawater. When examining mixtures of phototoxic PAHs in crude oil, laboratory studies suggested that toxicity adhered to an "additive interactions" model; therefore, predictive toxicity models should consider an additivity model for assessing the toxicity of hydrocarbon mixtures. Furthermore, PAH phototoxic potency seemed to increase with increasing methylation for all phototoxic PAHs examined. In fact, phenanthrene, a non-phototoxic PAH, demonstrated a slight degree of phototoxicity when methylated. Overall, predictive models based on HOMO-LUMO gap were relatively accurate in predicting phototoxicity compared with empirical data generated in the present study. Future models should consider effects of other substituents on photo-enhanced toxicity of PAHs due to toxicity differences between unsubstituted and alkylated PAHs observed in the present studies. Data presented in this dissertation, can be used in part, as the basis for an ecological risk assessment for the photo-enhanced toxicity of oil constituents in the Gulf of Mexico during the Deepwater Horizon oil spill. Title: Photo-enhanced Toxicity of Oil Constituents and Corexit 9500 to Gulf of Mexico Marine Organisms Author: Finch, Bryson E. Significant inputs of hydrocarbons are continually released into the environment from anthropogenic and natural sources. Some of the most toxic hydrocarbon compounds are polycyclic aromatic hydrocarbons. Polycyclic aromatic hydrocarbons are known for their ability to absorb ultraviolet light and enhance toxicity. Generally, PAHs exert their toxicity via narcosis but UV-absorbing PAHs can become photosensitized and significantly exacerbate toxic effects. During crude oil spills, PAHs are released in large amounts that have potential for narcotic and phototoxic effects on aquatic organisms. As a result of the Deepwater Horizon oil spill, effort was placed on quantifying toxic effects of crude oils and oil constituents for aquatic organisms. The following studies attempted to characterize narcotic and phototoxic effects that may have occurred during the Deepwater Horizon incident; however, the results of this research are equally applicable to any PAH exposure scenario. The objectives of the following studies were to: 1) identify susceptible stages of Gulf of Mexico organisms to the photo-enhanced toxicity of PAHs, 2) determine the importance of UV intensity and exposure duration on phototoxicity, 3) determine the effect of alkylation on the phototoxic potency of PAHs, 4) validate the assumption of additivity for phototoxic PAHs mixtures, 5) evaluate the potential for narcotic toxicity and phototoxicity of fresh and weathered Macondo crude oils released from the Deepwater Horizon, and 6) assess the potential for ongoing oil phototoxicity at field sites in the Gulf of Mexico. Model organisms used in studies included the mysid shrimp (Americamysis bahia), inland silverside (Menidia beryllina), sheepshead minnow (Cyprinodon variegatus), and Gulf killifish (Fundulus grandis). Studies demonstrated that organism sensitivity to phototoxicity of PAHs decreased with organism age and increasing pigmentation. Photo-enhanced toxicity was, to some extent, dependent on the degree of organism pigmentation. Generally, high-intensity short-duration UV treatments resulted in greater toxicity than low-intensity long-duration UV treatments at similar UV doses. Fresh Macondo crude oil was more toxic than weathered crude oils, both in the presence and absence of UV light. Differences in toxicity between fresh and weathered crude oils were primarily attributed to the lighter mono and di-aromatic hydrocarbons in fresh crude oils. Phototoxic PAH concentrations were relatively similar among fresh and weathered crude oils, suggesting recalcitrance to oil weathering processes. The addition of Corexit 9500, an oil-dispersant used during the Deepwater Horizon oil spill, to crude oil in laboratory experiments increased toxicity compared to tests conducted with crude oil alone. It is anticipated that this enhanced response resulted from the increased concentrations of phototoxic and narcotic PAHs in water-accommodated fractions and the inherent toxicity of Corexit 9500. Weathered crude oil present in previously heavily-oiled Barataria Bay, LA field sites was found to pose little or no phototoxic risk in ambient environmental conditions four years after the Deepwater Horizon oil spill. Water-accommodated fractions of field-collected oil suggest slight phototoxic potential to mysid shrimp in the laboratory in highly transparent artificial seawater. When examining mixtures of phototoxic PAHs in crude oil, laboratory studies suggested that toxicity adhered to an "additive interactions" model; therefore, predictive toxicity models should consider an additivity model for assessing the toxicity of hydrocarbon mixtures. Furthermore, PAH phototoxic potency seemed to increase with increasing methylation for all phototoxic PAHs examined. In fact, phenanthrene, a non-phototoxic PAH, demonstrated a slight degree of phototoxicity when methylated. Overall, predictive models based on HOMO-LUMO gap were relatively accurate in predicting phototoxicity compared with empirical data generated in the present study. Future models should consider effects of other substituents on photo-enhanced toxicity of PAHs due to toxicity differences between unsubstituted and alkylated PAHs observed in the present studies. Data presented in this dissertation, can be used in part, as the basis for an ecological risk assessment for the photo-enhanced toxicity of oil constituents in the Gulf of Mexico during the Deepwater Horizon oil spill. Close

• 3154. [Article] Mass-spectrometric Methods for Quantitative Proteomics and Post-translational Modification Mapping

  Signal transduction within and between cells is at the core of biological activity in all living systems. Signaling networks are required for regulating biological functions, including growth, development ...

  Citation × Citation Citation Abstract Copy Title: Mass-spectrometric Methods for Quantitative Proteomics and Post-translational Modification Mapping Author: Motorykin, Ievgen Signal transduction within and between cells is at the core of biological activity in all living systems. Signaling networks are required for regulating biological functions, including growth, development and survival. Deregulation of signaling cascades has been linked to chronic and acute diseases and disorders This thesis focuses on mass spectrometry as a high resolution and high mass accuracy technique for the detection and characterization of proteins in biological systems. The thesis presents applications of contemporary mass-spectrometric methods to identify proteins, determine changes in their expression levels, and characterize post-translational modifications, in an effort to study changes in cell signaling in response to stress or disease. Various sample preparation methods to successfully suit needs of different biological questions were developed and applied: (1) extraction of the proteome, (2) chemical tagging and enrichment of the ATPome, a sub proteome comprising nucleotide binding proteins in particularly ATP-binding proteins including kinases, and (3) metal affinity complexation and enrichment of phosphopeptides. We used the following hybrid mass analyzer configurations: a quadrupole time-of-flight (qToF) instrument with ion mobility, a linear ion trap hyphenated with a FT-ICR mass spectrometry (LTQ-FT) and a hybrid ion trap-orbitrap mass spectrometer (Orbitrap Elite). The bioinformatic analysis of the proteomics data required multiple combinations of software packages to sequence proteins, perform absolute and relative quantification, statistically analyze and visualize data. Chapter 3 describes the use of zebrafish (Danio rerio) as one of the few vertebrate models that similar to humans cannot synthesize vitamin C to investigate the system-wide consequences of deficiencies in two essential micronutrients, vitamins E and C, on the proteome biology. A label-free proteomics workflow was applied to detect changes in protein abundance estimates dependent on vitamin regimes. The study reveals suppression in an energy metabolism cycle, glycolysis, in vitamin C and E deficient zebrafish. It was discovered that alternative energy cycle, glutaminolysis, is activated to fulfill energy requirement. Chapter 4 focuses on the determination of proteome differences that can be linked to the propensity of metastasis in osteosarcoma (OS), a bone cancer that predominantly targets the adolescent age group. OS has a high propensity to metastasize to the lungs, which is associated with a poor prognosis. The study utilizes canine osteosarcoma cell lines that were originally obtained from orthotropic primary OS and metastatic cells. Canis familiaris, the domestic dog, is an established large animal model of OS that recapitulate many biological and clinical features of the human malignancy. We applied a two-prone comparative proteomics approach that consisted of: (a) determination of protein abundance levels and (b) focus on kinases, a functional sub-proteome, using a chemical affinity tag for enrichment of ATP-binding proteins. Findings of this study indicated that in the highly metastasizing canine osteosarcoma cell line proteins associated with extracellular adhesion were deregulated, which may enhance metastogenesis. Mitogen activated protein kinases MAP2K6, MAP4K3, MAP4K4, MAP4K5, ZAK and v-akt murine thymoma viral oncogene homolog 1, AKT1, are among those expressed in significantly lower abundance in the highly metastasizing canine osteosarcoma cell line indicating changes in cell signaling. Chapter 5 describes the development and application of a multiple protease protocol (Trypsin, LysC, AspN, Chymotrypsin and GluC) for improving the number of phosphosite identifications in a large-scale phosphoproteomics studies. The method combines immobilized titanium ion affinity chromatography (Ti⁴⁺-IMAC) with a data-dependent, decision tree-based data acquisition technique utilizing two complementary fragmentation methods, namely collision induced dissociation (CID) and electron transfer dissociation. The multiple protease protocol was applied to human leukemic T cell lymphoblasts (Jurkat E6.1) and resulted in the detection of >11,000 unique phosphosites, the most comprehensive identification among methods that use similar phosphopeptide enrichment approach. Title: Mass-spectrometric Methods for Quantitative Proteomics and Post-translational Modification Mapping Author: Motorykin, Ievgen Signal transduction within and between cells is at the core of biological activity in all living systems. Signaling networks are required for regulating biological functions, including growth, development and survival. Deregulation of signaling cascades has been linked to chronic and acute diseases and disorders This thesis focuses on mass spectrometry as a high resolution and high mass accuracy technique for the detection and characterization of proteins in biological systems. The thesis presents applications of contemporary mass-spectrometric methods to identify proteins, determine changes in their expression levels, and characterize post-translational modifications, in an effort to study changes in cell signaling in response to stress or disease. Various sample preparation methods to successfully suit needs of different biological questions were developed and applied: (1) extraction of the proteome, (2) chemical tagging and enrichment of the ATPome, a sub proteome comprising nucleotide binding proteins in particularly ATP-binding proteins including kinases, and (3) metal affinity complexation and enrichment of phosphopeptides. We used the following hybrid mass analyzer configurations: a quadrupole time-of-flight (qToF) instrument with ion mobility, a linear ion trap hyphenated with a FT-ICR mass spectrometry (LTQ-FT) and a hybrid ion trap-orbitrap mass spectrometer (Orbitrap Elite). The bioinformatic analysis of the proteomics data required multiple combinations of software packages to sequence proteins, perform absolute and relative quantification, statistically analyze and visualize data. Chapter 3 describes the use of zebrafish (Danio rerio) as one of the few vertebrate models that similar to humans cannot synthesize vitamin C to investigate the system-wide consequences of deficiencies in two essential micronutrients, vitamins E and C, on the proteome biology. A label-free proteomics workflow was applied to detect changes in protein abundance estimates dependent on vitamin regimes. The study reveals suppression in an energy metabolism cycle, glycolysis, in vitamin C and E deficient zebrafish. It was discovered that alternative energy cycle, glutaminolysis, is activated to fulfill energy requirement. Chapter 4 focuses on the determination of proteome differences that can be linked to the propensity of metastasis in osteosarcoma (OS), a bone cancer that predominantly targets the adolescent age group. OS has a high propensity to metastasize to the lungs, which is associated with a poor prognosis. The study utilizes canine osteosarcoma cell lines that were originally obtained from orthotropic primary OS and metastatic cells. Canis familiaris, the domestic dog, is an established large animal model of OS that recapitulate many biological and clinical features of the human malignancy. We applied a two-prone comparative proteomics approach that consisted of: (a) determination of protein abundance levels and (b) focus on kinases, a functional sub-proteome, using a chemical affinity tag for enrichment of ATP-binding proteins. Findings of this study indicated that in the highly metastasizing canine osteosarcoma cell line proteins associated with extracellular adhesion were deregulated, which may enhance metastogenesis. Mitogen activated protein kinases MAP2K6, MAP4K3, MAP4K4, MAP4K5, ZAK and v-akt murine thymoma viral oncogene homolog 1, AKT1, are among those expressed in significantly lower abundance in the highly metastasizing canine osteosarcoma cell line indicating changes in cell signaling. Chapter 5 describes the development and application of a multiple protease protocol (Trypsin, LysC, AspN, Chymotrypsin and GluC) for improving the number of phosphosite identifications in a large-scale phosphoproteomics studies. The method combines immobilized titanium ion affinity chromatography (Ti⁴⁺-IMAC) with a data-dependent, decision tree-based data acquisition technique utilizing two complementary fragmentation methods, namely collision induced dissociation (CID) and electron transfer dissociation. The multiple protease protocol was applied to human leukemic T cell lymphoblasts (Jurkat E6.1) and resulted in the detection of >11,000 unique phosphosites, the most comprehensive identification among methods that use similar phosphopeptide enrichment approach. Close

• 3155. [Article] Dispersal Behavior in African Buffalo (Syncerus caffer) : Tradeoffs Between Nutritional Resources and Disease Exposure

  Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management ...

  Citation × Citation Citation Abstract Copy Title: Dispersal Behavior in African Buffalo (Syncerus caffer) : Tradeoffs Between Nutritional Resources and Disease Exposure Author: Spaan, Robert Steven Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management implications, particularly with respect to disease spread. Although the role of adult dispersal in spreading disease has been documented, the potential influence of disease on dispersal has received little attention. African buffalo (Syncerus caffer) are wide ranging and harbor many pathogens that can affect nearby livestock. Dispersal of adult buffalo has been well documented, but ecological and social drivers of buffalo dispersal are poorly understood. At the individual level, animals must balance the potential benefits of dispersal against its costs. Costs may be incurred in the form of risk, such as mortality or potential injury while dispersing, energetic and time costs associated with the energy and time invested in dispersing, and costs associated with lost opportunities, e.g. reduced fecundity due to unfamiliar surroundings and social groups. Disease in particular is another poorly-understood but potentially important factor influencing costs and benefits of dispersal. Dispersal from a crowded habitat may offer an escape from high pathogen and parasite exposure risk, conversely dispersing individuals in this stressful period may have reduced immunity and consequently be more susceptible to infections. In addition, if pathogen exposure profiles differ among social groups, dispersing animals may face new pathogen challenges to which they are immunologically naïve to, when they arrive at a new social group. However, few studies have estimated dispersal costs of large mammals, particularly those with facultative adult dispersal. First, we investigated drivers of adult buffalo dispersal to determine whether likelihood of dispersal for individual female buffalo was influenced by (1) animal traits, including age, condition, and reproductive status (2) herd membership, (3) environmental variables - season and year, (4) gastro-intestinal parasites - strongyles, coccidia and schistosomes and (5) microparasite infections - bovine tuberculosis (Mycobacterium bovis) and brucellosis (Brucella abortus). The likelihood and drivers of buffalo dispersal varied by herd, area and year. In the Lower Sabie herd younger individuals were more likely to disperse, with most dispersal occurring in the early wet season and during an unusually dry year, 2009. In the Crocodile Bridge area buffalo in poor condition were most likely to disperse. Our findings suggest that dispersal of female buffalo is driven by either seasonal (Lower Sabie), or perhaps social (Crocodile Bridge) resource restriction. We found no direct effects of infections on buffalo dispersal, assuaging fears that highly infectious individuals might be more prone to dispersing, which could accelerate the spatial spread of infectious diseases. Second, we investigated: (1) effects of dispersal on fitness, by comparing survival, and fecundity of dispersing and philopatric (control) buffalo, as well as comparing the difference in pre and post dispersal body condition of dispersers with the change of body condition of philopatric control animals for the same period; (2) disease risks associated with dispersal, by determining whether burdens of gastro-intestinal parasites and the incidence of bacterial and viral infections changed during dispersal. No significant difference in mortality risk or fecundity was observed between dispersing and philopatric control animals, nor did change in body condition differ. However, we detected disease consequences of dispersal that varied by location. Dispersers from the resource-limited herd suffered more bovine tuberculosis and brucellosis infections after dispersal, both of which are chronic infections with clear, long term effects on survival and fecundity, when compared to controls from the same location. Dispersers from the less resource-limited herds had increases in schistosome burdens. Schistosomes are parasitic worms with relatively minor health effects; relatively long-lived but not as long as the life of the host (i.e., buffalo can reduce their burdens). Previous work has shown that adult buffalo disperse in response to resource limitation due to seasonal forage shortages or density dependent Title: Dispersal Behavior in African Buffalo (Syncerus caffer) : Tradeoffs Between Nutritional Resources and Disease Exposure Author: Spaan, Robert Steven Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management implications, particularly with respect to disease spread. Although the role of adult dispersal in spreading disease has been documented, the potential influence of disease on dispersal has received little attention. African buffalo (Syncerus caffer) are wide ranging and harbor many pathogens that can affect nearby livestock. Dispersal of adult buffalo has been well documented, but ecological and social drivers of buffalo dispersal are poorly understood. At the individual level, animals must balance the potential benefits of dispersal against its costs. Costs may be incurred in the form of risk, such as mortality or potential injury while dispersing, energetic and time costs associated with the energy and time invested in dispersing, and costs associated with lost opportunities, e.g. reduced fecundity due to unfamiliar surroundings and social groups. Disease in particular is another poorly-understood but potentially important factor influencing costs and benefits of dispersal. Dispersal from a crowded habitat may offer an escape from high pathogen and parasite exposure risk, conversely dispersing individuals in this stressful period may have reduced immunity and consequently be more susceptible to infections. In addition, if pathogen exposure profiles differ among social groups, dispersing animals may face new pathogen challenges to which they are immunologically naïve to, when they arrive at a new social group. However, few studies have estimated dispersal costs of large mammals, particularly those with facultative adult dispersal. First, we investigated drivers of adult buffalo dispersal to determine whether likelihood of dispersal for individual female buffalo was influenced by (1) animal traits, including age, condition, and reproductive status (2) herd membership, (3) environmental variables - season and year, (4) gastro-intestinal parasites - strongyles, coccidia and schistosomes and (5) microparasite infections - bovine tuberculosis (Mycobacterium bovis) and brucellosis (Brucella abortus). The likelihood and drivers of buffalo dispersal varied by herd, area and year. In the Lower Sabie herd younger individuals were more likely to disperse, with most dispersal occurring in the early wet season and during an unusually dry year, 2009. In the Crocodile Bridge area buffalo in poor condition were most likely to disperse. Our findings suggest that dispersal of female buffalo is driven by either seasonal (Lower Sabie), or perhaps social (Crocodile Bridge) resource restriction. We found no direct effects of infections on buffalo dispersal, assuaging fears that highly infectious individuals might be more prone to dispersing, which could accelerate the spatial spread of infectious diseases. Second, we investigated: (1) effects of dispersal on fitness, by comparing survival, and fecundity of dispersing and philopatric (control) buffalo, as well as comparing the difference in pre and post dispersal body condition of dispersers with the change of body condition of philopatric control animals for the same period; (2) disease risks associated with dispersal, by determining whether burdens of gastro-intestinal parasites and the incidence of bacterial and viral infections changed during dispersal. No significant difference in mortality risk or fecundity was observed between dispersing and philopatric control animals, nor did change in body condition differ. However, we detected disease consequences of dispersal that varied by location. Dispersers from the resource-limited herd suffered more bovine tuberculosis and brucellosis infections after dispersal, both of which are chronic infections with clear, long term effects on survival and fecundity, when compared to controls from the same location. Dispersers from the less resource-limited herds had increases in schistosome burdens. Schistosomes are parasitic worms with relatively minor health effects; relatively long-lived but not as long as the life of the host (i.e., buffalo can reduce their burdens). Previous work has shown that adult buffalo disperse in response to resource limitation due to seasonal forage shortages or density dependent Close

• 3156. [Article] The impact of Oregon’s Coordinated Care Organizations on Prenatal Care Access and Quality : A Difference-in-Differences Analysis

  Background: Prenatal care (PNC) is an important preventive health service that can influence the health of the four million women who give birth annually in the United States, and the health their infants. ...

  Citation × Citation Citation Abstract Copy Title: The impact of Oregon’s Coordinated Care Organizations on Prenatal Care Access and Quality : A Difference-in-Differences Analysis Author: Muoto, Ifeoma O. Background: Prenatal care (PNC) is an important preventive health service that can influence the health of the four million women who give birth annually in the United States, and the health their infants. Despite efforts to increase women’s access to PNC services, significant disparities in PNC utilization and maternal/child health outcomes by insurance type and race/ethnicity persist in the United States. The past decade has witnessed several major health reforms at both national and state levels. However, the impact of these reforms on the quality of PNC, and on disparities in PNC utilization is not known. In 2012, the state of Oregon established Coordinated Care Organizations (CCOs) as comprehensive providers of care for Oregon’s Medicaid beneficiaries. CCOs are characterized by a global budget payment mechanism and financial incentives for high quality care. Timely initiation of PNC – which has been associated with improved maternal and infant health and utilization outcomes – is one of seventeen quality metrics for which CCOs can receive incentive payments. Objectives: The first objective of the current study was to estimate the impact of CCO implementation on the probability of initiating PNC in the first trimester, and on PNC adequacy among Oregon Medicaid beneficiaries. The second objective of the study was to determine if the implementation of CCOs influenced disparities in PNC utilization between Medicaid and privately-insured women, and between non-Hispanic White women and Hispanic/non-Hispanic Black women. Study Design: This quasi-experimental retrospective observational study drew from two data sources: Oregon Vital Records (Birth Certificate statistical files) from the department of Health Analytics of the Oregon state public health department and Washington State’s Linked Birth- CHARS (Comprehensive Hospital Abstract Reporting System) data from the Washington State department of health. A difference-in-differences approach examined PNC utilization before and after CCO implementation. Washington State served as the control group, as its Medicaid financing and delivery systems remained unchanged. Multivariable linear probability analysis was used to control for confounding factors, including maternal age, race/ethnicity, education, parity, marital status, smoking history, previous preterm birth, and maternal morbidity. Population Studied: All births in Oregon and Washington from 2008 – 2013, which were covered by either Medicaid or private insurance, were included in the analysis. Since CCOs started operating mid-year in 2012, June through December 2012 was considered a transition period and births during this period were excluded from the analysis. Principal Findings: CCO implementation was associated with a significant increase in the probability of PNC initiation in the first trimester and a reduction in insurance-type disparities in first trimester PNC initiation and PNC adequacy among Oregon Medicaid beneficiaries. Racial/ethnic disparities did not change following CCO implementation. Conclusions: The implementation of CCOs in Oregon had a positive impact on the timeliness of PNC initiation among Medicaid beneficiaries, and also reduced disparities in PNC quality between Medicaid and privately-insured women. Implications for Policy or Practice: The ongoing health system transformation in Oregon provides an ideal setting to assess the impact of a novel health service delivery model on PNC utilization. If Oregon is successful in this bold and unprecedented move, it could serve as a model for other Medicaid and commercial health plans seeking to improve PNC quality. Further study on the longer-term effects of CCO implementation on PNC quality as well as the effect of CCOs on other health care domains, is warranted. Title: The impact of Oregon’s Coordinated Care Organizations on Prenatal Care Access and Quality : A Difference-in-Differences Analysis Author: Muoto, Ifeoma O. Background: Prenatal care (PNC) is an important preventive health service that can influence the health of the four million women who give birth annually in the United States, and the health their infants. Despite efforts to increase women’s access to PNC services, significant disparities in PNC utilization and maternal/child health outcomes by insurance type and race/ethnicity persist in the United States. The past decade has witnessed several major health reforms at both national and state levels. However, the impact of these reforms on the quality of PNC, and on disparities in PNC utilization is not known. In 2012, the state of Oregon established Coordinated Care Organizations (CCOs) as comprehensive providers of care for Oregon’s Medicaid beneficiaries. CCOs are characterized by a global budget payment mechanism and financial incentives for high quality care. Timely initiation of PNC – which has been associated with improved maternal and infant health and utilization outcomes – is one of seventeen quality metrics for which CCOs can receive incentive payments. Objectives: The first objective of the current study was to estimate the impact of CCO implementation on the probability of initiating PNC in the first trimester, and on PNC adequacy among Oregon Medicaid beneficiaries. The second objective of the study was to determine if the implementation of CCOs influenced disparities in PNC utilization between Medicaid and privately-insured women, and between non-Hispanic White women and Hispanic/non-Hispanic Black women. Study Design: This quasi-experimental retrospective observational study drew from two data sources: Oregon Vital Records (Birth Certificate statistical files) from the department of Health Analytics of the Oregon state public health department and Washington State’s Linked Birth- CHARS (Comprehensive Hospital Abstract Reporting System) data from the Washington State department of health. A difference-in-differences approach examined PNC utilization before and after CCO implementation. Washington State served as the control group, as its Medicaid financing and delivery systems remained unchanged. Multivariable linear probability analysis was used to control for confounding factors, including maternal age, race/ethnicity, education, parity, marital status, smoking history, previous preterm birth, and maternal morbidity. Population Studied: All births in Oregon and Washington from 2008 – 2013, which were covered by either Medicaid or private insurance, were included in the analysis. Since CCOs started operating mid-year in 2012, June through December 2012 was considered a transition period and births during this period were excluded from the analysis. Principal Findings: CCO implementation was associated with a significant increase in the probability of PNC initiation in the first trimester and a reduction in insurance-type disparities in first trimester PNC initiation and PNC adequacy among Oregon Medicaid beneficiaries. Racial/ethnic disparities did not change following CCO implementation. Conclusions: The implementation of CCOs in Oregon had a positive impact on the timeliness of PNC initiation among Medicaid beneficiaries, and also reduced disparities in PNC quality between Medicaid and privately-insured women. Implications for Policy or Practice: The ongoing health system transformation in Oregon provides an ideal setting to assess the impact of a novel health service delivery model on PNC utilization. If Oregon is successful in this bold and unprecedented move, it could serve as a model for other Medicaid and commercial health plans seeking to improve PNC quality. Further study on the longer-term effects of CCO implementation on PNC quality as well as the effect of CCOs on other health care domains, is warranted. Close

• 3157. [Article] Paleoceanography of the Eastern Equatorial Pacific during the Neogene : synthesis of Leg 138 drilling results

  The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change during the Neogene. Two north south transects were drilled (95° and 110°W) within ...

  Citation × Citation Citation Abstract Copy Title: Paleoceanography of the Eastern Equatorial Pacific during the Neogene : synthesis of Leg 138 drilling results Author: Mayer, Larry A., Pisias, Nicklas G., Mix, Alan C. The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change during the Neogene. Two north south transects were drilled (95° and 110°W) within the region of equatorial divergence driven upwelling (and thus high accumulation rates and resolution) and spanning the major equatorial ocean current boundaries (and thus recording a high amplitude signal of the response of the sediment to climatically and/or tectonically driven changes in ocean circulation). The Neogene is marked by a number of well known climatic and tectonic events (the closing of the Isthmus of Panama, the onset of North Atlantic Deep Water (NADW), the rapid uplift of the Himalayas, the major intensification of Northern Hemisphere glaciation), and the response of the ocean before and after these events was a key focus of Leg 138 drilling. To address these objectives at the highest resolution possible, the Leg 138 scientific staff developed a number of new shipboard strategies and analytical procedures. These included the real time analysis of the near continuous gamma ray attenuation porosity evaluator (GRAPE) and susceptibility profiles produced by the multisensor track (MST) on unsplit cores to monitor core recovery and, if necessary, to modify the drilling strategy to ensure proper offset of coring gaps; the collection of near continuous color reflectance data on split cores; the logging of the first hole drilled at each site to optimize drilling and sampling strategies for subsequent holes; and the use of multiple continuous records to unambiguously construct complete composite sections for each site. The complete, continuous records provided by the GRAPE (with a temporal resolution of often yr), in conjunction with an excellent microfossil stratigraphy and often excellent magnetostratigraphy, allowed for astronomical tuning of the stratigraphic record and resulted in a set of internally consistent, high resolution age models that provide a secure, absolute time scale for the past 6 m.y. For the period before 6 m.y., the absolute time calibration is less secure, but it is still better than any previously offered. The high resolution stratigraphic framework of Leg 138 provided new insight into the previously ambiguous tectonic history of the region. By assuming that maximum sedimentation rates along the north south transect would be expected at the equator, the Leg 138 stratigraphy supports the 1985 work of Cox and Engerbretson, which calls for two different poles of rotation of the Pacific Plate during the interval 0-20 Ma. The Leg 138 plate reconstructions also support several previously hypothesized ridge crest jumps and a slowing of the absolute motion of the Nazca Plate at about 5 Ma. Although Leg 138 data that predates about 13 Ma is limited, the impression that one can gain from these data is that the eastern equatorial Pacific was characterized by relatively high carbonate concentrations and accumulation rates before about 11 Ma. This pattern was interrupted occasionally by rapid massive outpourings of near monospecific laminated diatom oozes that probably represent the formation of massive mats along strong surface water fronts. The laminated diatom oozes (LDO) continue to be present in the Leg 138 record (many of them being expressed as seismic reflections) until about 4.4 Ma. Carbonate accumulation rates begin to decline slowly between 11 and 9.8 Ma, when, at about 9.5 Ma, a near complete loss of carbonate (the "carbonate crash") takes place everywhere in the Leg 138 region (and beyond), except at the westernmost sites close to the equator. The "carbonate crash" was a time of fundamental change for the eastern equatorial Pacific, and perhaps for most of the ocean basins. Unlike many of the carbonate variations that precede and postdate it, this "crash" represents a major dissolution event whose effects can be traced seismically in the central and western Pacific. The changes in bottom water chemistry associated with this event (or series of events) appear to be related to the early phases of the closing of the Panama Gateway. The role of NADW initiation and intensification for controlling carbonate accumulation in the eastern equatorial Pacific is still not resolved; however, ocean modeling demonstrates that the closing of the Panama Gateway may also have a direct influence on NADW production. Therefore, the effects of changes in the Panama Gateway sill depth and the production of NADW may be manifested in the history of eastern equatorial Pacific sedimentation. The "carbonate crash" was followed by a recovery of the carbonate system (except in the Guatemala and Peru basins, which never recovered) that led up to the late Miocene/ early Pliocene sedimentation rate maxima, during which equatorial sedimentation rates are as much as five times greater than those of the late Pliocene or Pleistocene. Examination of modern productivity/ preser vation relationships implies that the sedimentation rate maximum was the result of enhanced productivity. The distribution of eolian sediments and isotopic gradients, along with an analysis of the modes of variance in carbonate deposition over the last 6 m.y., suggest a more northerly position of the Intertropical Convergence Zone (ITCZ), a stronger north south gradient across the equator, and a more zonal circulation focused along the equator during the time of maximum sedimentation. The mechanisms suggested for these changes in circulation patterns include the response of the eastern equatorial Pacific to the closing of the Isthmus of Panama, as well as a global increase in the flux of Ca and Si into the oceans, a possible response to evolution of the Himalayas and the Tibetan Plateau. In an effort to understand the response of the climate system to external (orbital) forcing, 6-m.y.-long, continuous records of carbonate (derived from GRAPE), δ¹⁸O and insolation were analyzed and compared. Evolutionary spectral calculations of the variance and coherence among these records indicate that the insolation record is dominated by precessional frequencies, but that the relative importance of the two precessional frequencies has changed significantly over the last 6 m.y. In general, precessional forcing is not found in the carbonate or isotopic records. In the tilt band, however, a linear response is present between solar forcing and the carbonate and isotope records over some intervals. The carbonate record appears to be tightly coupled to the tilt component of insolation before about 1.9 Ma; however, the isotope record does not begin to show sensitivity to orbital tilt until about 4.5 Ma, the time of significant changes in sedimentation patterns in the eastern equatorial Pacific. Only during the last 500,000 yr do all frequencies respond in a similar manner; we also see a marked increase in the response of the isotopic record to orbital forcing (including 100,000- and 400,000-yr periods). Title: Paleoceanography of the Eastern Equatorial Pacific during the Neogene : synthesis of Leg 138 drilling results Author: Mayer, Larry A., Pisias, Nicklas G., Mix, Alan C. The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change during the Neogene. Two north south transects were drilled (95° and 110°W) within the region of equatorial divergence driven upwelling (and thus high accumulation rates and resolution) and spanning the major equatorial ocean current boundaries (and thus recording a high amplitude signal of the response of the sediment to climatically and/or tectonically driven changes in ocean circulation). The Neogene is marked by a number of well known climatic and tectonic events (the closing of the Isthmus of Panama, the onset of North Atlantic Deep Water (NADW), the rapid uplift of the Himalayas, the major intensification of Northern Hemisphere glaciation), and the response of the ocean before and after these events was a key focus of Leg 138 drilling. To address these objectives at the highest resolution possible, the Leg 138 scientific staff developed a number of new shipboard strategies and analytical procedures. These included the real time analysis of the near continuous gamma ray attenuation porosity evaluator (GRAPE) and susceptibility profiles produced by the multisensor track (MST) on unsplit cores to monitor core recovery and, if necessary, to modify the drilling strategy to ensure proper offset of coring gaps; the collection of near continuous color reflectance data on split cores; the logging of the first hole drilled at each site to optimize drilling and sampling strategies for subsequent holes; and the use of multiple continuous records to unambiguously construct complete composite sections for each site. The complete, continuous records provided by the GRAPE (with a temporal resolution of often yr), in conjunction with an excellent microfossil stratigraphy and often excellent magnetostratigraphy, allowed for astronomical tuning of the stratigraphic record and resulted in a set of internally consistent, high resolution age models that provide a secure, absolute time scale for the past 6 m.y. For the period before 6 m.y., the absolute time calibration is less secure, but it is still better than any previously offered. The high resolution stratigraphic framework of Leg 138 provided new insight into the previously ambiguous tectonic history of the region. By assuming that maximum sedimentation rates along the north south transect would be expected at the equator, the Leg 138 stratigraphy supports the 1985 work of Cox and Engerbretson, which calls for two different poles of rotation of the Pacific Plate during the interval 0-20 Ma. The Leg 138 plate reconstructions also support several previously hypothesized ridge crest jumps and a slowing of the absolute motion of the Nazca Plate at about 5 Ma. Although Leg 138 data that predates about 13 Ma is limited, the impression that one can gain from these data is that the eastern equatorial Pacific was characterized by relatively high carbonate concentrations and accumulation rates before about 11 Ma. This pattern was interrupted occasionally by rapid massive outpourings of near monospecific laminated diatom oozes that probably represent the formation of massive mats along strong surface water fronts. The laminated diatom oozes (LDO) continue to be present in the Leg 138 record (many of them being expressed as seismic reflections) until about 4.4 Ma. Carbonate accumulation rates begin to decline slowly between 11 and 9.8 Ma, when, at about 9.5 Ma, a near complete loss of carbonate (the "carbonate crash") takes place everywhere in the Leg 138 region (and beyond), except at the westernmost sites close to the equator. The "carbonate crash" was a time of fundamental change for the eastern equatorial Pacific, and perhaps for most of the ocean basins. Unlike many of the carbonate variations that precede and postdate it, this "crash" represents a major dissolution event whose effects can be traced seismically in the central and western Pacific. The changes in bottom water chemistry associated with this event (or series of events) appear to be related to the early phases of the closing of the Panama Gateway. The role of NADW initiation and intensification for controlling carbonate accumulation in the eastern equatorial Pacific is still not resolved; however, ocean modeling demonstrates that the closing of the Panama Gateway may also have a direct influence on NADW production. Therefore, the effects of changes in the Panama Gateway sill depth and the production of NADW may be manifested in the history of eastern equatorial Pacific sedimentation. The "carbonate crash" was followed by a recovery of the carbonate system (except in the Guatemala and Peru basins, which never recovered) that led up to the late Miocene/ early Pliocene sedimentation rate maxima, during which equatorial sedimentation rates are as much as five times greater than those of the late Pliocene or Pleistocene. Examination of modern productivity/ preser vation relationships implies that the sedimentation rate maximum was the result of enhanced productivity. The distribution of eolian sediments and isotopic gradients, along with an analysis of the modes of variance in carbonate deposition over the last 6 m.y., suggest a more northerly position of the Intertropical Convergence Zone (ITCZ), a stronger north south gradient across the equator, and a more zonal circulation focused along the equator during the time of maximum sedimentation. The mechanisms suggested for these changes in circulation patterns include the response of the eastern equatorial Pacific to the closing of the Isthmus of Panama, as well as a global increase in the flux of Ca and Si into the oceans, a possible response to evolution of the Himalayas and the Tibetan Plateau. In an effort to understand the response of the climate system to external (orbital) forcing, 6-m.y.-long, continuous records of carbonate (derived from GRAPE), δ¹⁸O and insolation were analyzed and compared. Evolutionary spectral calculations of the variance and coherence among these records indicate that the insolation record is dominated by precessional frequencies, but that the relative importance of the two precessional frequencies has changed significantly over the last 6 m.y. In general, precessional forcing is not found in the carbonate or isotopic records. In the tilt band, however, a linear response is present between solar forcing and the carbonate and isotope records over some intervals. The carbonate record appears to be tightly coupled to the tilt component of insolation before about 1.9 Ma; however, the isotope record does not begin to show sensitivity to orbital tilt until about 4.5 Ma, the time of significant changes in sedimentation patterns in the eastern equatorial Pacific. Only during the last 500,000 yr do all frequencies respond in a similar manner; we also see a marked increase in the response of the isotopic record to orbital forcing (including 100,000- and 400,000-yr periods). Close

• 3158. [Article] Piscivorous colonial waterbirds in the Columbia River estuary : demography, dietary contaminants, and management

  Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus) nest in large colonies on East Sand Island in the Columbia River estuary, the largest known colonies for the two ...

  Citation × Citation Citation Abstract Copy Title: Piscivorous colonial waterbirds in the Columbia River estuary : demography, dietary contaminants, and management Author: Suzuki, Yasuko Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus) nest in large colonies on East Sand Island in the Columbia River estuary, the largest known colonies for the two species in the world. Both species of piscivorous colonial waterbirds have been identified as predators with a significant impact on the survival of juvenile salmonids (Oncorhynchus spp.) listed under the U.S. Endangered Species Act. To better understand and address issues related to seabird-fisheries interactions in the Columbia River estuary, I conducted studies related to the ecology, conservation, and management of these two species of piscivorous waterbirds. I evaluated the demographics and inter-colony movements of Caspian terns belonging to the Pacific Coast metapopulation, with special emphasis on two breeding colonies, one on East Sand Island in the Columbia River estuary and the other on Crescent Island in the mid-Columbia River, based on re-sightings of color-banded individuals. Apparent annual adult survival at both colonies was high, and age at first reproduction was greater than previously reported for the species. Colony site philopatry of breeding adults at both colonies was high; however, some individuals prospected for breeding colonies over much of the Pacific Coast region and moved to other colonies over distances of up to 3,000 km. Some terns from the large colony in the Columbia River estuary responded quickly to the availability of new colony sites as distant as 550 km from the estuary, and established successful breeding colonies within less than a year of the new sites becoming available. The Caspian tern colony on East Sand Island appears to be an important source colony for a number of smaller, less productive colonies distributed over an extensive area from the Salton Sea, California to the Copper River Delta, Alaska, an area with limited and ephemeral nesting opportunities. Environmental contaminants have been a conservation concern for wildlife in the Columbia River estuary, especially species that consume fish and are therefore likely to bioaccumulate persistent organic pollutants. I measured and compared levels of polychlorinated biphenyls (PCBs) in eggs and chicks of Caspian terns and doublecrested cormorants, as well as their primary prey fish types, at colonies on East Sand Island and farther up-river. Based on differences in tern and cormorant diet composition at the various study colonies, higher PCB levels in eggs and chicks were associated with diets dominated by resident freshwater and estuarine fishes. PCB levels in prey fish were positively correlated with lipid content; however, PCB levels in the livers of chicks were negatively correlated with chick fat scores, suggesting that chick fat reserves are a sink for ingested PCBs. Lower PCB levels in terns and cormorants from East Sand Island compared to colonies farther up-river reflected diets with a higher proportion of marine forage fishes at East Sand Island; marine forage fishes had lower average levels of PCBs than their resident freshwater and estuarine counterparts. In order to explore non-destructive techniques for managing nesting colonies of double-crested cormorants, I evaluated habitat enhancement and social attraction, two techniques that have proven effective for relocating Caspian tern colonies to sites where impacts on fish stocks of conservation concern would be minimal. Cormorants were attracted to nest and successfully raised young at test plots on East Sand Island and on islands in the estuary with a previous history of cormorant nesting or unsuccessful nesting attempts. On an island with no history of cormorant nesting or prospecting, however, no cormorants were attracted to nest. My results suggest that attraction of nesting cormorants using these techniques is dependent on the previous history of cormorant nesting or nesting attempts, the frequency and intensity of disturbance by potential predators, and the presence of breeding cormorants nearby. While habitat enhancement and social attraction have potential as methods for redistributing nesting cormorants away from areas where fish stocks of concern are highly susceptible to predation, successful establishment of new colonies using these techniques will likely require a focus on sites with a history of cormorant nesting. Findings from this dissertation raise some concerns over the management of Caspian tern and double-crested cormorant colonies on East Sand Island in order to redistribute parts of these colonies to alternative sites and mitigate the impact of those piscivorous colonial waterbirds on ESA-listed salmonids. East Sand Island has supported source colonies of piscivorous colonial waterbirds for many smaller colonies throughout the region and is close to an abundant and relatively uncontaminated food supply. Also, alternative colony sites that can substitute for East Sand Island are not readily apparent, especially for double-crested cormorants. Therefore, management of Caspian tern and double-crested cormorant colonies on East Sand Island to benefit Columbia Basin salmonids needs to proceed cautiously and reversibly because of the implications for the region-wide populations of these piscivorous colonial waterbirds. Title: Piscivorous colonial waterbirds in the Columbia River estuary : demography, dietary contaminants, and management Author: Suzuki, Yasuko Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus) nest in large colonies on East Sand Island in the Columbia River estuary, the largest known colonies for the two species in the world. Both species of piscivorous colonial waterbirds have been identified as predators with a significant impact on the survival of juvenile salmonids (Oncorhynchus spp.) listed under the U.S. Endangered Species Act. To better understand and address issues related to seabird-fisheries interactions in the Columbia River estuary, I conducted studies related to the ecology, conservation, and management of these two species of piscivorous waterbirds. I evaluated the demographics and inter-colony movements of Caspian terns belonging to the Pacific Coast metapopulation, with special emphasis on two breeding colonies, one on East Sand Island in the Columbia River estuary and the other on Crescent Island in the mid-Columbia River, based on re-sightings of color-banded individuals. Apparent annual adult survival at both colonies was high, and age at first reproduction was greater than previously reported for the species. Colony site philopatry of breeding adults at both colonies was high; however, some individuals prospected for breeding colonies over much of the Pacific Coast region and moved to other colonies over distances of up to 3,000 km. Some terns from the large colony in the Columbia River estuary responded quickly to the availability of new colony sites as distant as 550 km from the estuary, and established successful breeding colonies within less than a year of the new sites becoming available. The Caspian tern colony on East Sand Island appears to be an important source colony for a number of smaller, less productive colonies distributed over an extensive area from the Salton Sea, California to the Copper River Delta, Alaska, an area with limited and ephemeral nesting opportunities. Environmental contaminants have been a conservation concern for wildlife in the Columbia River estuary, especially species that consume fish and are therefore likely to bioaccumulate persistent organic pollutants. I measured and compared levels of polychlorinated biphenyls (PCBs) in eggs and chicks of Caspian terns and doublecrested cormorants, as well as their primary prey fish types, at colonies on East Sand Island and farther up-river. Based on differences in tern and cormorant diet composition at the various study colonies, higher PCB levels in eggs and chicks were associated with diets dominated by resident freshwater and estuarine fishes. PCB levels in prey fish were positively correlated with lipid content; however, PCB levels in the livers of chicks were negatively correlated with chick fat scores, suggesting that chick fat reserves are a sink for ingested PCBs. Lower PCB levels in terns and cormorants from East Sand Island compared to colonies farther up-river reflected diets with a higher proportion of marine forage fishes at East Sand Island; marine forage fishes had lower average levels of PCBs than their resident freshwater and estuarine counterparts. In order to explore non-destructive techniques for managing nesting colonies of double-crested cormorants, I evaluated habitat enhancement and social attraction, two techniques that have proven effective for relocating Caspian tern colonies to sites where impacts on fish stocks of conservation concern would be minimal. Cormorants were attracted to nest and successfully raised young at test plots on East Sand Island and on islands in the estuary with a previous history of cormorant nesting or unsuccessful nesting attempts. On an island with no history of cormorant nesting or prospecting, however, no cormorants were attracted to nest. My results suggest that attraction of nesting cormorants using these techniques is dependent on the previous history of cormorant nesting or nesting attempts, the frequency and intensity of disturbance by potential predators, and the presence of breeding cormorants nearby. While habitat enhancement and social attraction have potential as methods for redistributing nesting cormorants away from areas where fish stocks of concern are highly susceptible to predation, successful establishment of new colonies using these techniques will likely require a focus on sites with a history of cormorant nesting. Findings from this dissertation raise some concerns over the management of Caspian tern and double-crested cormorant colonies on East Sand Island in order to redistribute parts of these colonies to alternative sites and mitigate the impact of those piscivorous colonial waterbirds on ESA-listed salmonids. East Sand Island has supported source colonies of piscivorous colonial waterbirds for many smaller colonies throughout the region and is close to an abundant and relatively uncontaminated food supply. Also, alternative colony sites that can substitute for East Sand Island are not readily apparent, especially for double-crested cormorants. Therefore, management of Caspian tern and double-crested cormorant colonies on East Sand Island to benefit Columbia Basin salmonids needs to proceed cautiously and reversibly because of the implications for the region-wide populations of these piscivorous colonial waterbirds. Close

• 3159. [Article] Geology of the Hamlet-North Fork of the Nehalem River area, southern Clatsop and northernmost Tillamook Counties, northwest Oregon

  The middle to late Eocene tholeiitic Tillamook Volcanics compose the oldest rock unit in the Hamlet-North Fork of the Nehalem River area. Geochemical plots and field relationships indicate that these rocks ...

  Citation × Citation Citation Abstract Copy Title: Geology of the Hamlet-North Fork of the Nehalem River area, southern Clatsop and northernmost Tillamook Counties, northwest Oregon Author: Rarey, Phillip Jay The middle to late Eocene tholeiitic Tillamook Volcanics compose the oldest rock unit in the Hamlet-North Fork of the Nehalem River area. Geochemical plots and field relationships indicate that these rocks were produced in an extensional tectonic setting in the developing forearc and formed an extensive tholeiltic oceanic island. The volcanics consi5t of a thick sequence of normally and reversely polarized subaerial basalt and basaltic andesite flows in the Hamlet-North Fork of the Nehalem River area. The "Gray's River area" Goble Volcanics in southwest Washington are chemically and stratigraphically correlative to the Tillamook Volcanics. Cessation of Tillamook volcanism resulted in thermal subsidence and transgression of the overlying Hamlet formation. Upper Narizian (middle to upper Eccene) nearshore fossiliferous basaltic boulder-pebble conglomerates and basaltic sandstones of the Roy Creek member of the Hamlet formation (informal) were deposited along a rocky basaltic coastline over the subsiding volcanic "island". Scanning electron microscopy shows that radial pore-filling chloritic cement has significantly reduced porosity in Roy Creek member sandstones. Micaceous and carbonaceous silty mudstones and rare thin basaltic turbidite sandstones of the Sweet Home Creek member of the Hamlet formation (informal> were deposited on the outer shelf to upper slope above the Roy Creek member as the basin continued to deepen. The Sweet Home Creek member contains abundant bathyal benthtc foraminifera assignable to the upper Narizian stage. Calcareous nannofossils collected from the unit have been assigned to subzone CP-14a which is in agreement with foraminifera data. The upper part of the Sweet Home Creek member is in part a deep marine correlative to shelf arkosic sandstones of the Cowltiz Formation which pinches out into the Sweet Home Creek member in eastern Clatsop County. Much of the detritus in the Sweet Home Creek member was derived from plutonic and metamorphic sources in contrast to the locally derived Roy Creek member. Calc-alkaline Cole Mountain basalt (informal) intrudes and overlies the Sweet Home Creek member. Cole Mountain basalt was formed in a compressional tectonic environment and emplaced on the outer continental shelf as shallow intrusions and submarine flow. The unit is chemically and petrographically distinct from the Tillamook Volcanics and chemically similar to and stratigraphically correlative to the type Goble Volcanics (e.g. low Ti02 and low P205). Unconformably overlying the Cole Mountain basalt and the Sweet Home Creek member is the bathyal, Refugian (upper Eocene), Jewell member of the Keasey Formation. It consists of three parts a basal glauconitic sandstone-siltstone, a laminated tuffaceous sandstone unit with rare small arkosic sandstone channels and occasional clastic dikes, and an upper laminated to bioturbated tuffaceous silt-mudstone. trkosic sandstones were derived from an ancesteral Columbia River system whereas abundant tuffaceous detritus was derived locally from the Cascade arc. The Refugian lower Smuggler Cove formation (informal) gradationally overlies the Jewell member and consists of bioturbated, tuffaceous, bathyal mudstones. Outer shelf, very fine-grained tuffaceous sandstones of the David Douglas tongue (informal) of the Pittsburg Bluff Formation and deeper marine correlative outer shelf to upper slope glauconitic sanstones of the middle Smuggler Cove formation overlie the lower Smuggler Cove formation. The upper Smuggler Cove formation consists of uppermost Refugian to Zemmorian bathyal, bioturbated, fossiliferous, well-indurated tuffaceous siltstone. Laminated carbonaceous mudetones and thin (<1/2 m) arkosic sandstone beds of the ball park unit in the Smuggler Cove formation overlie and interfinger with (7) the upper Smuggler Cove formation. The ball park unit is late Zemorrian (Oligocene) or Saucesian (Early Miocene) in age. Fluvial-deltaic to shallow marine sandstones and conglomerates of the lower to middle Miocene angora Peek member of the astoria Formation unconformably overlies the Smuggler Cove formation. Numerous middle to upper Miocene basalts and gabbros intrude the sedimentary rocks in the thesis area. The intrusive rocks are chemically, magnetically, petrographically, and chronologically correlative to the Grande Ronde Basalt, Frenchman Springs Member, and Pomona Member of the Columbia River Basalt Group on the Columbia Plateau. The Grande Ronde Basalt intrusives have been divided into three chemical-magnetostratigraphic units in the thesis area and correlated to subaerial Columbia River Basalt flows located approximately 35 km to the northeast. The intrusive rocks are thought to have formed by invasion of voluminous subaerial flows into soft, semiconsolidated marine sediments as first envisioned by Beeson et. al. (1979). Uplift of the Coast Range forearc ridge from late Miocene to present has resulted in subaerial erosion and exposure of rock units. Thin alluvial gravels and sands were deposited in the southeastern corner of the thesis area during the Quaternary. Structure in the thesis area is dominated by a series of east-west trending high angle faults and a younger series of conjugate northeast-and northwest-trending high angle oblique slip faults. Proton precession magnetometer traverses confirm the presence of the faults. The structure may have been produced by partial coupling of the forearc region with the subducting Farallon plate. The thesis area has been actively explored for hydrocarbons. Geologic mapping, however, shows that significant sandstone reservoirs are not present in the subsurface and, therefore, the area has low potential of hydrocarbon production. Mudstones in the thesis area average approximately 0.9-1.1% total organic carbon with vitrinite reflectance values ranging from 0.53% Ro (unbaked) to 0.72% Ro (baked). Therefore, the mudstones are a marginal to poor source of thermogenic gas but a possible source of methane gas. Title: Geology of the Hamlet-North Fork of the Nehalem River area, southern Clatsop and northernmost Tillamook Counties, northwest Oregon Author: Rarey, Phillip Jay The middle to late Eocene tholeiitic Tillamook Volcanics compose the oldest rock unit in the Hamlet-North Fork of the Nehalem River area. Geochemical plots and field relationships indicate that these rocks were produced in an extensional tectonic setting in the developing forearc and formed an extensive tholeiltic oceanic island. The volcanics consi5t of a thick sequence of normally and reversely polarized subaerial basalt and basaltic andesite flows in the Hamlet-North Fork of the Nehalem River area. The "Gray's River area" Goble Volcanics in southwest Washington are chemically and stratigraphically correlative to the Tillamook Volcanics. Cessation of Tillamook volcanism resulted in thermal subsidence and transgression of the overlying Hamlet formation. Upper Narizian (middle to upper Eccene) nearshore fossiliferous basaltic boulder-pebble conglomerates and basaltic sandstones of the Roy Creek member of the Hamlet formation (informal) were deposited along a rocky basaltic coastline over the subsiding volcanic "island". Scanning electron microscopy shows that radial pore-filling chloritic cement has significantly reduced porosity in Roy Creek member sandstones. Micaceous and carbonaceous silty mudstones and rare thin basaltic turbidite sandstones of the Sweet Home Creek member of the Hamlet formation (informal> were deposited on the outer shelf to upper slope above the Roy Creek member as the basin continued to deepen. The Sweet Home Creek member contains abundant bathyal benthtc foraminifera assignable to the upper Narizian stage. Calcareous nannofossils collected from the unit have been assigned to subzone CP-14a which is in agreement with foraminifera data. The upper part of the Sweet Home Creek member is in part a deep marine correlative to shelf arkosic sandstones of the Cowltiz Formation which pinches out into the Sweet Home Creek member in eastern Clatsop County. Much of the detritus in the Sweet Home Creek member was derived from plutonic and metamorphic sources in contrast to the locally derived Roy Creek member. Calc-alkaline Cole Mountain basalt (informal) intrudes and overlies the Sweet Home Creek member. Cole Mountain basalt was formed in a compressional tectonic environment and emplaced on the outer continental shelf as shallow intrusions and submarine flow. The unit is chemically and petrographically distinct from the Tillamook Volcanics and chemically similar to and stratigraphically correlative to the type Goble Volcanics (e.g. low Ti02 and low P205). Unconformably overlying the Cole Mountain basalt and the Sweet Home Creek member is the bathyal, Refugian (upper Eocene), Jewell member of the Keasey Formation. It consists of three parts a basal glauconitic sandstone-siltstone, a laminated tuffaceous sandstone unit with rare small arkosic sandstone channels and occasional clastic dikes, and an upper laminated to bioturbated tuffaceous silt-mudstone. trkosic sandstones were derived from an ancesteral Columbia River system whereas abundant tuffaceous detritus was derived locally from the Cascade arc. The Refugian lower Smuggler Cove formation (informal) gradationally overlies the Jewell member and consists of bioturbated, tuffaceous, bathyal mudstones. Outer shelf, very fine-grained tuffaceous sandstones of the David Douglas tongue (informal) of the Pittsburg Bluff Formation and deeper marine correlative outer shelf to upper slope glauconitic sanstones of the middle Smuggler Cove formation overlie the lower Smuggler Cove formation. The upper Smuggler Cove formation consists of uppermost Refugian to Zemmorian bathyal, bioturbated, fossiliferous, well-indurated tuffaceous siltstone. Laminated carbonaceous mudetones and thin (<1/2 m) arkosic sandstone beds of the ball park unit in the Smuggler Cove formation overlie and interfinger with (7) the upper Smuggler Cove formation. The ball park unit is late Zemorrian (Oligocene) or Saucesian (Early Miocene) in age. Fluvial-deltaic to shallow marine sandstones and conglomerates of the lower to middle Miocene angora Peek member of the astoria Formation unconformably overlies the Smuggler Cove formation. Numerous middle to upper Miocene basalts and gabbros intrude the sedimentary rocks in the thesis area. The intrusive rocks are chemically, magnetically, petrographically, and chronologically correlative to the Grande Ronde Basalt, Frenchman Springs Member, and Pomona Member of the Columbia River Basalt Group on the Columbia Plateau. The Grande Ronde Basalt intrusives have been divided into three chemical-magnetostratigraphic units in the thesis area and correlated to subaerial Columbia River Basalt flows located approximately 35 km to the northeast. The intrusive rocks are thought to have formed by invasion of voluminous subaerial flows into soft, semiconsolidated marine sediments as first envisioned by Beeson et. al. (1979). Uplift of the Coast Range forearc ridge from late Miocene to present has resulted in subaerial erosion and exposure of rock units. Thin alluvial gravels and sands were deposited in the southeastern corner of the thesis area during the Quaternary. Structure in the thesis area is dominated by a series of east-west trending high angle faults and a younger series of conjugate northeast-and northwest-trending high angle oblique slip faults. Proton precession magnetometer traverses confirm the presence of the faults. The structure may have been produced by partial coupling of the forearc region with the subducting Farallon plate. The thesis area has been actively explored for hydrocarbons. Geologic mapping, however, shows that significant sandstone reservoirs are not present in the subsurface and, therefore, the area has low potential of hydrocarbon production. Mudstones in the thesis area average approximately 0.9-1.1% total organic carbon with vitrinite reflectance values ranging from 0.53% Ro (unbaked) to 0.72% Ro (baked). Therefore, the mudstones are a marginal to poor source of thermogenic gas but a possible source of methane gas. Close

• 3160. [Article] The historic and contemporary ecology of western Cascade meadows : archeology, vegetation, and macromoth ecology

  Montane meadows in the western Cascades of Oregon occupy approximately 5% of the landscape, but contribute greatly to the region's biodiversity. Western Cascades meadows are dynamic parts of the landscape ...

  Citation × Citation Citation Abstract Copy Title: The historic and contemporary ecology of western Cascade meadows : archeology, vegetation, and macromoth ecology Author: Highland, Steven A. Montane meadows in the western Cascades of Oregon occupy approximately 5% of the landscape, but contribute greatly to the region's biodiversity. Western Cascades meadows are dynamic parts of the landscape and have contracted by over 50% in the past two hundred years in the HJ Andrews Experimental Forest (hereafter Andrews Forest). Many studies have linked the loss of meadows with local extirpation of species and loss of regional biodiversity, but these processes depend upon the factors that create and maintain meadows, and how species respond to meadow configuration. The prehistory of these meadows is poorly understood, as is the contemporary ecology. This study combined previously collected archeological and moth datasets, aerial photographs, and new plant, tree core, and moth data to investigate interactions between landforms, disturbance, vegetation, and moth abundance and diversity in montane meadows of the western Cascades of Oregon. Burning by prehistoric people may have created and maintained montane meadows, but relatively little evidence remains of the activities of prehistoric peoples in the western Cascades. This study assessed the extent to which prehistoric people preferentially used different landforms and vegetation types by inferring use from landscape distributions of archaeological sites. Descriptions of 359 previously recorded and four newly discovered archeological sites in the McKenzie River watershed of western Oregon were examined using GIS and chi-square analysis to determine how sites were distributed relative to classified vegetation and landforms of the 3700-km² McKenzie River watershed. The high ridges of the HJ Andrews Experimental Forest were analyzed using air photo change detection and archaeological field surveys to identify how archeological sites were distributed relative to landforms and vegetation communities, including meadows. The field surveys documented physical evidence (archeological sites) confirming Native American use of the meadows and surrounding open forests. The locations of these sites indicate that Native Americans utilized the edges between large open meadows and open forests, as well as gently sloping open meadows. The prior extent of meadows (before air photos) was estimated by dendrochronology of 220 trees along present-day and inferred past meadow edges. Forest age structure and the open-grown forms of Douglas fir suggests a much more open habitat, potentially due to fire, was present more than 200 years ago. Moths are major consumers of vegetation when in caterpillar stage and are food sources for many birds and mammals, and contribute greatly to the insect diversity in a region. Moth species richness and abundance may be associated with the distribution of vegetation communities and seasonal timing, and the conservation of rare moths may depend on the conservation of rare vegetation habitats. A dataset of moths sampled 10 times/year at 20 locations in the 64-km² Andrews Forest over the period 2004-2008 was analyzed using generalized linear mixed models (GLMM), non-metric multidimensional scaling (NMS), multi-response permutation procedure (MRPP), analysis of variance (ANOVA), and two tailed t-test to identify the overall patterns of rare and common moth distribution as well as moth community relationships to structurally and taxonomically derived vegetation classes and seasonality. Five hundred fourteen species and 69,168 macromoth individuals were identified. Moth species abundance and diversity were significantly higher in low elevation coniferous forests than in other vegetation types, according to the GLMM. Sixty-six rare moth species were significantly associated with high elevation open habitats. Species associated with meadows also were significantly more likely to be hardwood or herb-feeders than conifer-feeders as caterpillars, based on ANOVAs. The 26 most common moth species were significantly associated with low elevation coniferous forests and were more likely to be conifer-feeders as caterpillars, based on ANOVAs. Common moth species were significantly more likely to emerge earlier in warmer years than in cooler years, based on a two-tailed t-test. Managing the western Cascades landscape for moth biodiversity and for moth abundance requires maintenance and potentially expansion of rare upland habitats as well as lowland coniferous forests. Montane meadows in the Andrews Forest are contracting in size, but it is not known how these changes have affected moth and plant biodiversity. The rate and pattern of meadow contraction from 1949 to 2005 along the high ridges of the Andrews Forest were analyzed using air photo change detection. Overall meadows contracted by nearly 50% from 1949 to 2005, but rates of meadow loss were much higher for the largest meadow complexes. Plant community diversity in seventeen meadows and the diversity, abundance, and community structure of moths at 98 locations sampled in the summers of 2008, 2009, and 2010 were related to measures of meadow size, isolation, and other variables using cluster analysis (CLA), MRPP, NMS, and generalized additive models (GAMs). Plant diversity in meadows was significantly positively related to meadow area in 1949 and the distance of the meadow from the road, based on GAM analysis. Plant community structure was most closely correlated with meadow area in 1949 and slope, based on CLA, MRPP, and NMS analysis. Calendar day explained the most variation in moth species richness, abundance, and community structure, but the next most important explanatory variables differed according to feeding guild, based on GAMs. Richness, abundance, and community structure of herb-feeding moths was related to meadow area in 1949 and elevation. For angiosperm-feeding moths, area-perimeter ratio in 2005 explained the most variation in richness, abundance, and community structure after calendar day. For gymnosperm-feeding moths, meadow area change from 1949-2005, a variable measuring the amount of increase in coniferous tree cover, explained the most variation in richness, abundance, and community structure after calendar day. The abundance and diversity of herb-feeding moths and meadow plants exhibited a lagged response to habitat loss, which may indicate an extinction debt. In contrast, angiosperm-and gymnosperm-feeding moths responded quickly (within 50 years) to increases in their habitat. Managing for the conservation of biodiversity in the upper elevations of the Andrews Forest will require targeted management strategies for different groups of organisms. Herb-feeding moths and meadow plants will benefit from expansion of open meadow habitat, while angiosperm and gymnosperm-feeders will require the maintenance of edge environments and coniferous forests. Title: The historic and contemporary ecology of western Cascade meadows : archeology, vegetation, and macromoth ecology Author: Highland, Steven A. Montane meadows in the western Cascades of Oregon occupy approximately 5% of the landscape, but contribute greatly to the region's biodiversity. Western Cascades meadows are dynamic parts of the landscape and have contracted by over 50% in the past two hundred years in the HJ Andrews Experimental Forest (hereafter Andrews Forest). Many studies have linked the loss of meadows with local extirpation of species and loss of regional biodiversity, but these processes depend upon the factors that create and maintain meadows, and how species respond to meadow configuration. The prehistory of these meadows is poorly understood, as is the contemporary ecology. This study combined previously collected archeological and moth datasets, aerial photographs, and new plant, tree core, and moth data to investigate interactions between landforms, disturbance, vegetation, and moth abundance and diversity in montane meadows of the western Cascades of Oregon. Burning by prehistoric people may have created and maintained montane meadows, but relatively little evidence remains of the activities of prehistoric peoples in the western Cascades. This study assessed the extent to which prehistoric people preferentially used different landforms and vegetation types by inferring use from landscape distributions of archaeological sites. Descriptions of 359 previously recorded and four newly discovered archeological sites in the McKenzie River watershed of western Oregon were examined using GIS and chi-square analysis to determine how sites were distributed relative to classified vegetation and landforms of the 3700-km² McKenzie River watershed. The high ridges of the HJ Andrews Experimental Forest were analyzed using air photo change detection and archaeological field surveys to identify how archeological sites were distributed relative to landforms and vegetation communities, including meadows. The field surveys documented physical evidence (archeological sites) confirming Native American use of the meadows and surrounding open forests. The locations of these sites indicate that Native Americans utilized the edges between large open meadows and open forests, as well as gently sloping open meadows. The prior extent of meadows (before air photos) was estimated by dendrochronology of 220 trees along present-day and inferred past meadow edges. Forest age structure and the open-grown forms of Douglas fir suggests a much more open habitat, potentially due to fire, was present more than 200 years ago. Moths are major consumers of vegetation when in caterpillar stage and are food sources for many birds and mammals, and contribute greatly to the insect diversity in a region. Moth species richness and abundance may be associated with the distribution of vegetation communities and seasonal timing, and the conservation of rare moths may depend on the conservation of rare vegetation habitats. A dataset of moths sampled 10 times/year at 20 locations in the 64-km² Andrews Forest over the period 2004-2008 was analyzed using generalized linear mixed models (GLMM), non-metric multidimensional scaling (NMS), multi-response permutation procedure (MRPP), analysis of variance (ANOVA), and two tailed t-test to identify the overall patterns of rare and common moth distribution as well as moth community relationships to structurally and taxonomically derived vegetation classes and seasonality. Five hundred fourteen species and 69,168 macromoth individuals were identified. Moth species abundance and diversity were significantly higher in low elevation coniferous forests than in other vegetation types, according to the GLMM. Sixty-six rare moth species were significantly associated with high elevation open habitats. Species associated with meadows also were significantly more likely to be hardwood or herb-feeders than conifer-feeders as caterpillars, based on ANOVAs. The 26 most common moth species were significantly associated with low elevation coniferous forests and were more likely to be conifer-feeders as caterpillars, based on ANOVAs. Common moth species were significantly more likely to emerge earlier in warmer years than in cooler years, based on a two-tailed t-test. Managing the western Cascades landscape for moth biodiversity and for moth abundance requires maintenance and potentially expansion of rare upland habitats as well as lowland coniferous forests. Montane meadows in the Andrews Forest are contracting in size, but it is not known how these changes have affected moth and plant biodiversity. The rate and pattern of meadow contraction from 1949 to 2005 along the high ridges of the Andrews Forest were analyzed using air photo change detection. Overall meadows contracted by nearly 50% from 1949 to 2005, but rates of meadow loss were much higher for the largest meadow complexes. Plant community diversity in seventeen meadows and the diversity, abundance, and community structure of moths at 98 locations sampled in the summers of 2008, 2009, and 2010 were related to measures of meadow size, isolation, and other variables using cluster analysis (CLA), MRPP, NMS, and generalized additive models (GAMs). Plant diversity in meadows was significantly positively related to meadow area in 1949 and the distance of the meadow from the road, based on GAM analysis. Plant community structure was most closely correlated with meadow area in 1949 and slope, based on CLA, MRPP, and NMS analysis. Calendar day explained the most variation in moth species richness, abundance, and community structure, but the next most important explanatory variables differed according to feeding guild, based on GAMs. Richness, abundance, and community structure of herb-feeding moths was related to meadow area in 1949 and elevation. For angiosperm-feeding moths, area-perimeter ratio in 2005 explained the most variation in richness, abundance, and community structure after calendar day. For gymnosperm-feeding moths, meadow area change from 1949-2005, a variable measuring the amount of increase in coniferous tree cover, explained the most variation in richness, abundance, and community structure after calendar day. The abundance and diversity of herb-feeding moths and meadow plants exhibited a lagged response to habitat loss, which may indicate an extinction debt. In contrast, angiosperm-and gymnosperm-feeding moths responded quickly (within 50 years) to increases in their habitat. Managing for the conservation of biodiversity in the upper elevations of the Andrews Forest will require targeted management strategies for different groups of organisms. Herb-feeding moths and meadow plants will benefit from expansion of open meadow habitat, while angiosperm and gymnosperm-feeders will require the maintenance of edge environments and coniferous forests. Close