Search

Search Results

• 381. [Article] Redox processes in a seasonally reduced riparian zone soil ecosystem

  Seasonal reducing conditions play an important role in the cycling of nutrients and soil pore water chemical constituents in the Willamette Valley. Long periods of soil saturation lead microorganisms utilizing ...

  Citation × Citation Citation Abstract Copy Title: Redox processes in a seasonally reduced riparian zone soil ecosystem Author: Roland, Rio Seasonal reducing conditions play an important role in the cycling of nutrients and soil pore water chemical constituents in the Willamette Valley. Long periods of soil saturation lead microorganisms utilizing organic matter as their carbon source to find alternative electron acceptors other than oxygen. Once oxygen has been depleted microorganisms sequentially use nitrate, manganese (IV), iron (III), and sulfate. Soil mineral solubility often controls the release of these pore water chemical constituents, and thus is an important component of the biogeochemistry of soils. Soil pore waters were sampled using pore water equilibration devices, or peepers. Peepers give a high resolution of the concentration of pore water chemical constituents with depth. They also sample pore waters without oxidizing the constituents and thus give a realistic view of the species in situ. Peepers have been widely used in sampling the pore waters of lake and ocean bottom sediment and peat bogs. However, no literature was found on the use of peepers in dense saturated mineral soils. The results from this experiment support the idea that carbon is an important determinant in the concentration of reduced species. All reduced species were most heavily concentrated at the depth that dissolved and solid soil organic carbon were most concentrated. Organic phosphorus was present in concentrations of an order of magnitude greater than inorganic phophorus. Organic matter apperars to be an important regulator of phosphorus. The soluble inorganic phosphorus concentration trend appeared to be correlated with the iron (II) concentration trend; thus, suggesting the importance of iron reduction in phosphate release. Inorganic phosphorus was found at concentrations of an order of magnitude greater under anaerobic conditions than under aerobic conditions. Minteqa2, a geochemical model, was used to evaluate which soil minerals are likely controlling the solubility of pore water chemical constituents. Ferrihydrite, goethite, green rust, and lepidocrocite all showed trends of increasing saturation index with increasing redox potential. The soil pore waters are over-saturated with respect to goethite and lepidocrocite. Both of these minerals have been observed in Willamette Valley soils under oxic conditions. Under-saturation was observed with respect to ferrihydrite and mackinawite suggesting dissolution of these mineral phases. Siderite was only slightly oversaturated. The thermodynamic modeling approach gives useful insight into the possible mineral solids that may form. However, identification of the important Fe solid phases awaits additional investigation using microscopic techniques such as, x-ray diffraction, Mossbauer spectroscopy, or other surface techniques. Title: Redox processes in a seasonally reduced riparian zone soil ecosystem Author: Roland, Rio Seasonal reducing conditions play an important role in the cycling of nutrients and soil pore water chemical constituents in the Willamette Valley. Long periods of soil saturation lead microorganisms utilizing organic matter as their carbon source to find alternative electron acceptors other than oxygen. Once oxygen has been depleted microorganisms sequentially use nitrate, manganese (IV), iron (III), and sulfate. Soil mineral solubility often controls the release of these pore water chemical constituents, and thus is an important component of the biogeochemistry of soils. Soil pore waters were sampled using pore water equilibration devices, or peepers. Peepers give a high resolution of the concentration of pore water chemical constituents with depth. They also sample pore waters without oxidizing the constituents and thus give a realistic view of the species in situ. Peepers have been widely used in sampling the pore waters of lake and ocean bottom sediment and peat bogs. However, no literature was found on the use of peepers in dense saturated mineral soils. The results from this experiment support the idea that carbon is an important determinant in the concentration of reduced species. All reduced species were most heavily concentrated at the depth that dissolved and solid soil organic carbon were most concentrated. Organic phosphorus was present in concentrations of an order of magnitude greater than inorganic phophorus. Organic matter apperars to be an important regulator of phosphorus. The soluble inorganic phosphorus concentration trend appeared to be correlated with the iron (II) concentration trend; thus, suggesting the importance of iron reduction in phosphate release. Inorganic phosphorus was found at concentrations of an order of magnitude greater under anaerobic conditions than under aerobic conditions. Minteqa2, a geochemical model, was used to evaluate which soil minerals are likely controlling the solubility of pore water chemical constituents. Ferrihydrite, goethite, green rust, and lepidocrocite all showed trends of increasing saturation index with increasing redox potential. The soil pore waters are over-saturated with respect to goethite and lepidocrocite. Both of these minerals have been observed in Willamette Valley soils under oxic conditions. Under-saturation was observed with respect to ferrihydrite and mackinawite suggesting dissolution of these mineral phases. Siderite was only slightly oversaturated. The thermodynamic modeling approach gives useful insight into the possible mineral solids that may form. However, identification of the important Fe solid phases awaits additional investigation using microscopic techniques such as, x-ray diffraction, Mossbauer spectroscopy, or other surface techniques. Close

• 382. [Article] Implications of a nonlinear ⁴⁰Ar/³⁹Ar age progression along the Louisville seamount trail for models of fixed and moving hot spots

  Copyrighted by American Geophysical Union.

  Citation × Citation Citation Abstract Copy Title: Implications of a nonlinear ⁴⁰Ar/³⁹Ar age progression along the Louisville seamount trail for models of fixed and moving hot spots Author: Koppers, Anthony A. P., Steinberger, Bernhard, Duncan, Robert A. Copyrighted by American Geophysical Union. Title: Implications of a nonlinear ⁴⁰Ar/³⁹Ar age progression along the Louisville seamount trail for models of fixed and moving hot spots Author: Koppers, Anthony A. P., Steinberger, Bernhard, Duncan, Robert A. Copyrighted by American Geophysical Union. Close

• 383. [Article] Castle Rocks : a late miocene eruptive center at the north end of Green Ridge, Jefferson County, Oregon

  Castle Rocks is 12 miles east of Mt. Jefferson, in the central Cascades of Oregon. The area contains volcanic rocks ranging from mid-Miocene to Holocene in age. These rocks record alternating periods of ...

  Citation × Citation Citation Abstract Copy Title: Castle Rocks : a late miocene eruptive center at the north end of Green Ridge, Jefferson County, Oregon Author: Wendland, David W. Castle Rocks is 12 miles east of Mt. Jefferson, in the central Cascades of Oregon. The area contains volcanic rocks ranging from mid-Miocene to Holocene in age. These rocks record alternating periods of tholeiitic and calc-alkaline volcanism. The oldest rocks in the area range from basaltic andesite lava flows to fayalite-bearing dacite breccias, and are best exposed near the confluence of the Metolius and Whitewater rivers. Petrographic and compositional evidence indicates that the dacites are highly differentiated products of a tholeiitic fractionation trend. The dacites were apparently derived from basalt by the fractionation of olivine, clinopyroxene and plagioclase. The most prominent feature of the thesis area is the remnant of a calc-alkaline composite volcano of late Miocene age. The center of the volcano is marked by a pyroxene andesite plug near the north end of Green Ridge. This "Castle Rocks Volcano" produced andesitic lava flows and pyroclastic rocks characterized by abundant hornblende phenocrysts. Compositional trends are consistent with fractionation of hornblende, clinopyroxene and possibly plagioclase. The Castle Rocks Volcano is unconformably overlain by ash-flow tuffs and basaltic andesite lavas of the Deschutes Formation. The unconformity represents a period of change from compressional to extensional tectonics. Deschutes Formation rocks show tholeiitic compositional trends, apparently produced by the fractionation of olivine, clinopyroxene and plagioclase. North-south normal faulting on the Green Ridge fault system terminated deposition of the Deschutes Formation at about 5.4 Ma. Three parallel faults in the thesis area are spaced about 0.5 miles apart. Maximum displacement is about 2200 ft, in the southern part of the thesis area, and decreases to a negligible amount at the confluence of the Metolius and Whitewater rivers. High Cascade rocks representing two magma types erupted after the episode of normal faulting. Subduction-related, calc-alkaline basaltic andesites are confined to the area west of the Green Ridge fault scarp. They show compostional patterns very similar to those of the Castle Rocks Andesites, but are less phyric and lack hornblende. Diktytaxitic basalts spread east to the north of the Green Ridge fault scarp to form Metolius Bench. Younger diktytaxitic basalts flowed down the canyon of the Metolius River. The diktytaxitic basalts are unrelated to the High Cascade basaltic andesites. Instead, they are similar to extension-related high alumina olivine tholeiites of the northwestern Great Basin. Title: Castle Rocks : a late miocene eruptive center at the north end of Green Ridge, Jefferson County, Oregon Author: Wendland, David W. Castle Rocks is 12 miles east of Mt. Jefferson, in the central Cascades of Oregon. The area contains volcanic rocks ranging from mid-Miocene to Holocene in age. These rocks record alternating periods of tholeiitic and calc-alkaline volcanism. The oldest rocks in the area range from basaltic andesite lava flows to fayalite-bearing dacite breccias, and are best exposed near the confluence of the Metolius and Whitewater rivers. Petrographic and compositional evidence indicates that the dacites are highly differentiated products of a tholeiitic fractionation trend. The dacites were apparently derived from basalt by the fractionation of olivine, clinopyroxene and plagioclase. The most prominent feature of the thesis area is the remnant of a calc-alkaline composite volcano of late Miocene age. The center of the volcano is marked by a pyroxene andesite plug near the north end of Green Ridge. This "Castle Rocks Volcano" produced andesitic lava flows and pyroclastic rocks characterized by abundant hornblende phenocrysts. Compositional trends are consistent with fractionation of hornblende, clinopyroxene and possibly plagioclase. The Castle Rocks Volcano is unconformably overlain by ash-flow tuffs and basaltic andesite lavas of the Deschutes Formation. The unconformity represents a period of change from compressional to extensional tectonics. Deschutes Formation rocks show tholeiitic compositional trends, apparently produced by the fractionation of olivine, clinopyroxene and plagioclase. North-south normal faulting on the Green Ridge fault system terminated deposition of the Deschutes Formation at about 5.4 Ma. Three parallel faults in the thesis area are spaced about 0.5 miles apart. Maximum displacement is about 2200 ft, in the southern part of the thesis area, and decreases to a negligible amount at the confluence of the Metolius and Whitewater rivers. High Cascade rocks representing two magma types erupted after the episode of normal faulting. Subduction-related, calc-alkaline basaltic andesites are confined to the area west of the Green Ridge fault scarp. They show compostional patterns very similar to those of the Castle Rocks Andesites, but are less phyric and lack hornblende. Diktytaxitic basalts spread east to the north of the Green Ridge fault scarp to form Metolius Bench. Younger diktytaxitic basalts flowed down the canyon of the Metolius River. The diktytaxitic basalts are unrelated to the High Cascade basaltic andesites. Instead, they are similar to extension-related high alumina olivine tholeiites of the northwestern Great Basin. Close

• 384. [Article] Addressing wastewater epidemiology limitations with the use of dynamic population surrogates, complementary urinalyses and in-situ experiments

  Wastewater epidemiology is an emerging discipline that requires collaborative research involving analytical chemists, drug epidemiologists, and wastewater engineers. Wastewater epidemiology involves the ...

  Citation × Citation Citation Abstract Copy Title: Addressing wastewater epidemiology limitations with the use of dynamic population surrogates, complementary urinalyses and in-situ experiments Author: Brewer, Alex J. Wastewater epidemiology is an emerging discipline that requires collaborative research involving analytical chemists, drug epidemiologists, and wastewater engineers. Wastewater epidemiology involves the sampling and quantitative analysis of raw wastewaters from communities for illicit drugs and their metabolites. Mass loads (mass per day) and per capita (mg per day per person) are then calculated from concentrations and indicate the approximate quantity of illicit drugs used and excreted by the community. Limitations to wastewater epidemiology include that the population served by wastewater treatment plants within a day and between days is not well known. In addition, biodegradation of illicit drugs during transit in sewers may affect the concentration and mass flows that reach wastewater treatment plants. This thesis describes a series of studies conducted by an international collaboration between scientists and engineers from the United States and Switzerland to answer these two limitations. The experimental approaches for these studies used included high-frequency wastewater sampling strategies, the use of creatinine as a human urinary biomarker, as well as the use of unique locations as test sites including an open community, a prison in the state of Oregon, and a 5 km section of sewer in Zürich Switzerland. In Chapter 2, the diurnal study on the mass flows of illicit drugs or metabolites was formed over four days in a municipality with a population of approximately 55,000 people. The diurnal trends in illicit substances vary by substance. The high (g/day) mass flows of caffeine, methamphetamine, and creatinine indicate that lower-frequency sampling (approximately one sample per h) may representatively capture the use and excretion of these substances. However, lower and episodic mass flows of cocaine and its primary human metabolite, benzoylecgonine, indicate that higher-frequency is needed to accurately assess the use of the cocaine within the municipality. Normalization of illicit substances to creatinine gave between-day trends in illicit and legal substances that differed from non-normalized trends. Resident use of cocaine and methamphetamine were indicated by normalized mass flows that increased during early morning hours while commuters are largely absent from the community. Chapter 3 describes a series of experiments conducted at an Oregon state prison. The prison setting provided a unique opportunity to study a nearly-fixed population of individuals and their corresponding mass flows of illicit substances, the number of doses per person consumed, as well as an opportunity to quantify the level of agreement between numbers of individuals and the measured mass flows of creatinine. Methamphetamine use was more prevalent than cocaine/benzoylecgonine in the prison over the one month study in which single daily (24 h) composite samples of wastewater were collected. The hypothesis that the mass flows of methamphetamine and cocaine would be lower on days on which random urinalysis testing (RUA) is typically conducted by the prison (Monday-Thursday) was rejected. While the mass flows (mg/d) of methamphetamine were less than those for a nearby open community, the number of estimated doses per person was higher for the prison population. A higher number of positive RUA results were obtained for methamphetamine while none were positive for cocaine, which is consistent with the data obtained from wastewater. The hourly (diurnal) trend in methamphetamine mass loads indicated continual methamphetamine use/excretion inside the prison while cocaine and benzoylecgonine were detected in five hourly composite samples. Use of methamphetamine and cocaine by inmates could not be unambiguously distinguished from that of non-inmates (employees and visitors). The observed diurnal trends in creatinine mass loads were similar to those of an open community and are indicative of the general pattern of human wakefulness/activity. Predicted creatinine mass loads based on the total prison (inmates + non-inmates) were in good agreement with the measured mass loads, which indicates the potential use of creatinine as a quantitative population indicator. Additional research on the biodegradability of creatinine is needed because the prison setting was deliberately selected to minimize the potential for creatinine biodegradation. Chapter 4 addresses the data gap that exists on illicit drug transformation during in situ transit in sewers. The rates of in situ biodegradation have not yet been determined for conditions that are relevant to sewers, which include low to variable oxygen concentrations, the presence of a biofilm, and temperatures ≤ 20 °C. For this reason, two tracer tests were conducted in a 5 km stretch of sewer located near Zürich, Switzerland. The stable-isotope forms (deuterated) of cocaine and benzoylecgonine were injected into flowing wastewater and three locations up to 5 km downstream were sampled over time. Breakthrough curves were constructed from measurements of cocaine-d3 and benzoylecgonine-d3 concentration with time. The area under the curve (mass) was determined by integrating concentration over time. Benzoylecgonine-d3 was present in the injectate that should have only contained cocaine-d3; because the benzoylecgonine-d3 formation prior to injection is not known. The injected mass of cocaine-d3 did not decline over the 5 km distance. The observed mass of cocaine-d3 at 5 km was 10% greater than at 500 m, which indicates that the transformation of cocaine was not significant over the 1.5 h experiment. At 5 km downgradient, the apparent mass of benzoylecgonine-d3 had increased by 35% over that observed at 500 m. However, the apparent increase in benzoylecgonine-d3 mass was not accompanied by a corresponding loss of cocaine-d3. While uncertainty is apparent in the increase of both cocaine-d3 and benzoylecgonine-d3, the ratio of cocaine-d3/benzoylecgonine-d3 is subject only to analytical error because any errors associated with sampling and the integration of masses cancel out. The ratio of cocaine-d3/benzoylecgonine-d3 declined from 2.98 in the injectate to 1.66 at Location 3, which indicated a greater increase in benzoylecgonine-d3 relative to cocaine over the 5 km distance. Due to the benzoylecgonine-d3 that was present in the injectate, any biodegradation of cocaine-c3 to form benzoylecgonine-d3 could not be unambiguously distinguished. During the second tracer test in which benzoylecgonine-d3 was injected, the mass of benzoylecgonine-d3 did not significantly decline, which suggests that the apparent loss of benzoylecgonine-d3 during the cocaine-d3 test cannot be attributed to in-situ biodegradation. Overall, while uncertainty exists about the integrated masses for cocaine-d3 and benzoylecgonine-d3, the 5 km distance was too short in order to observe a significant loss of cocaine-d3 and formation of benzoylecgonine-d3. Recommendations for future research include conducting analysis on the injectate solution to ensure that only cocaine-d3 is introduced so that any formation of benzoylecgonine-d3 is readily apparent and quantifiable. In addition, the tracer tests should be repeated in a longer section of sewer to increase the residence time beyond 1.5 hr and degradation products of benzoylecgonine-d3 should be monitored including ecgonine and ecgonine methyl ester. Title: Addressing wastewater epidemiology limitations with the use of dynamic population surrogates, complementary urinalyses and in-situ experiments Author: Brewer, Alex J. Wastewater epidemiology is an emerging discipline that requires collaborative research involving analytical chemists, drug epidemiologists, and wastewater engineers. Wastewater epidemiology involves the sampling and quantitative analysis of raw wastewaters from communities for illicit drugs and their metabolites. Mass loads (mass per day) and per capita (mg per day per person) are then calculated from concentrations and indicate the approximate quantity of illicit drugs used and excreted by the community. Limitations to wastewater epidemiology include that the population served by wastewater treatment plants within a day and between days is not well known. In addition, biodegradation of illicit drugs during transit in sewers may affect the concentration and mass flows that reach wastewater treatment plants. This thesis describes a series of studies conducted by an international collaboration between scientists and engineers from the United States and Switzerland to answer these two limitations. The experimental approaches for these studies used included high-frequency wastewater sampling strategies, the use of creatinine as a human urinary biomarker, as well as the use of unique locations as test sites including an open community, a prison in the state of Oregon, and a 5 km section of sewer in Zürich Switzerland. In Chapter 2, the diurnal study on the mass flows of illicit drugs or metabolites was formed over four days in a municipality with a population of approximately 55,000 people. The diurnal trends in illicit substances vary by substance. The high (g/day) mass flows of caffeine, methamphetamine, and creatinine indicate that lower-frequency sampling (approximately one sample per h) may representatively capture the use and excretion of these substances. However, lower and episodic mass flows of cocaine and its primary human metabolite, benzoylecgonine, indicate that higher-frequency is needed to accurately assess the use of the cocaine within the municipality. Normalization of illicit substances to creatinine gave between-day trends in illicit and legal substances that differed from non-normalized trends. Resident use of cocaine and methamphetamine were indicated by normalized mass flows that increased during early morning hours while commuters are largely absent from the community. Chapter 3 describes a series of experiments conducted at an Oregon state prison. The prison setting provided a unique opportunity to study a nearly-fixed population of individuals and their corresponding mass flows of illicit substances, the number of doses per person consumed, as well as an opportunity to quantify the level of agreement between numbers of individuals and the measured mass flows of creatinine. Methamphetamine use was more prevalent than cocaine/benzoylecgonine in the prison over the one month study in which single daily (24 h) composite samples of wastewater were collected. The hypothesis that the mass flows of methamphetamine and cocaine would be lower on days on which random urinalysis testing (RUA) is typically conducted by the prison (Monday-Thursday) was rejected. While the mass flows (mg/d) of methamphetamine were less than those for a nearby open community, the number of estimated doses per person was higher for the prison population. A higher number of positive RUA results were obtained for methamphetamine while none were positive for cocaine, which is consistent with the data obtained from wastewater. The hourly (diurnal) trend in methamphetamine mass loads indicated continual methamphetamine use/excretion inside the prison while cocaine and benzoylecgonine were detected in five hourly composite samples. Use of methamphetamine and cocaine by inmates could not be unambiguously distinguished from that of non-inmates (employees and visitors). The observed diurnal trends in creatinine mass loads were similar to those of an open community and are indicative of the general pattern of human wakefulness/activity. Predicted creatinine mass loads based on the total prison (inmates + non-inmates) were in good agreement with the measured mass loads, which indicates the potential use of creatinine as a quantitative population indicator. Additional research on the biodegradability of creatinine is needed because the prison setting was deliberately selected to minimize the potential for creatinine biodegradation. Chapter 4 addresses the data gap that exists on illicit drug transformation during in situ transit in sewers. The rates of in situ biodegradation have not yet been determined for conditions that are relevant to sewers, which include low to variable oxygen concentrations, the presence of a biofilm, and temperatures ≤ 20 °C. For this reason, two tracer tests were conducted in a 5 km stretch of sewer located near Zürich, Switzerland. The stable-isotope forms (deuterated) of cocaine and benzoylecgonine were injected into flowing wastewater and three locations up to 5 km downstream were sampled over time. Breakthrough curves were constructed from measurements of cocaine-d3 and benzoylecgonine-d3 concentration with time. The area under the curve (mass) was determined by integrating concentration over time. Benzoylecgonine-d3 was present in the injectate that should have only contained cocaine-d3; because the benzoylecgonine-d3 formation prior to injection is not known. The injected mass of cocaine-d3 did not decline over the 5 km distance. The observed mass of cocaine-d3 at 5 km was 10% greater than at 500 m, which indicates that the transformation of cocaine was not significant over the 1.5 h experiment. At 5 km downgradient, the apparent mass of benzoylecgonine-d3 had increased by 35% over that observed at 500 m. However, the apparent increase in benzoylecgonine-d3 mass was not accompanied by a corresponding loss of cocaine-d3. While uncertainty is apparent in the increase of both cocaine-d3 and benzoylecgonine-d3, the ratio of cocaine-d3/benzoylecgonine-d3 is subject only to analytical error because any errors associated with sampling and the integration of masses cancel out. The ratio of cocaine-d3/benzoylecgonine-d3 declined from 2.98 in the injectate to 1.66 at Location 3, which indicated a greater increase in benzoylecgonine-d3 relative to cocaine over the 5 km distance. Due to the benzoylecgonine-d3 that was present in the injectate, any biodegradation of cocaine-c3 to form benzoylecgonine-d3 could not be unambiguously distinguished. During the second tracer test in which benzoylecgonine-d3 was injected, the mass of benzoylecgonine-d3 did not significantly decline, which suggests that the apparent loss of benzoylecgonine-d3 during the cocaine-d3 test cannot be attributed to in-situ biodegradation. Overall, while uncertainty exists about the integrated masses for cocaine-d3 and benzoylecgonine-d3, the 5 km distance was too short in order to observe a significant loss of cocaine-d3 and formation of benzoylecgonine-d3. Recommendations for future research include conducting analysis on the injectate solution to ensure that only cocaine-d3 is introduced so that any formation of benzoylecgonine-d3 is readily apparent and quantifiable. In addition, the tracer tests should be repeated in a longer section of sewer to increase the residence time beyond 1.5 hr and degradation products of benzoylecgonine-d3 should be monitored including ecgonine and ecgonine methyl ester. Close

• 385. [Article] Aspects of the foraging ecology of humpback whales (Megaptera novaeangliae) in Frederick Sound and Stephens Passage, Southeast Alaska

  The North Pacific humpback whale (Megaptera novaeangliae) population has been increasing at an average annual rate of ~6% since the early 1990s. In northern Southeast Alaska alone, there are now more whales ...

  Citation × Citation Citation Abstract Copy Title: Aspects of the foraging ecology of humpback whales (Megaptera novaeangliae) in Frederick Sound and Stephens Passage, Southeast Alaska Author: Szabo, Andrew, 1974- The North Pacific humpback whale (Megaptera novaeangliae) population has been increasing at an average annual rate of ~6% since the early 1990s. In northern Southeast Alaska alone, there are now more whales than estimated for the entire North Pacific several decades ago. An understanding of how this growing population is repopulating traditional foraging grounds will benefit from detailed investigations of their prey preferences and trends in whale abundance and distribution relative to those prey. This dissertation examines these issues from late May until early September 2008 in Frederick Sound and Stephens Passage, a Southeast Alaskan feeding area historically used by humpback whales. The foundation for the study is an analysis of the life histories and abundance patterns of euphausiids, the principal prey of humpbacks in the area, during late spring and summer. Four species, Thysanoessa raschii, T. longipes, T. spinifera, and Euphausia pacifica, were identified in plankton net samples collected at random locations throughout the study site (n = 49) and in locations where a strong scattering layer was observed on a 120 kHz echosounder (n = 48). Both sample types varied in euphausiid species composition. Abundance patterns of immature euphausiids coupled with observations of females carrying spermatophores indicated differences between species in spawning schedules. Thysanoessa spp. began spawning in early April with the spring phytoplankton bloom and continued until late June, whereas E. pacifica began spawning in early June and continued until late August. This protracted recruitment of immature euphausiids was geographically widespread throughout the summer in contrast to adults, which, although present all summer, were found primarily in slope and shallow (< 100 m) areas. To determine if humpback whales preferred one euphausiid species or life-stage over another, net sample and hydroacoustic data collected in the vicinity of whales were compared to similar data collected in random locations throughout the study site. This revealed that whales targeted dense aggregations of adult euphausiids, but did not discriminate between the various species, which was surprising because of presumed differences in the energy density linked to their different spawning schedules. Additionally, whales did not spend time in areas with concentrations of immature euphausiids, which were likely not large enough during the study period to be suitable prey. With this preference for adult euphausiids, the abundance and distribution patterns of humpbacks were examined in relation to prey availability. Whale abundance was lowest at the beginning of the study in late May at ca. 68 whales and peaked in late July at ca. 228 animals – approximately 12% of the region’s estimated abundance for the study year. This study did not detect a concomitant increase in the availability of adult euphausiids, which is unsurprising since immature euphausiids would not recruit into the adult population until after the end of the study, and post-spawning mortality and predation pressure is presumably high during this time. Instead, whales clustered increasingly around comparatively fewer prey as the summer progressed. These observations, combined with a plateau in whale abundance after July, suggest that their abundance in the area was limited by euphausiid availability. Estimates of whales using the study site during the summer have remained similar over several decades despite a dramatic increase in humpback numbers in Southeast Alaska and elsewhere in the North Pacific. The results from this study suggest that, although the study site remains important seasonally to some whales, it is not a significant source of prey responsible for regional population growth in general. More likely, it is part of a network of feeding areas that has influenced the population trend. Further insight into these and the other issues raised in this dissertation could come from several additional analyses. An extended sampling season that captures the recruitment of immature euphausiids into the adult population would reveal whether a given year's prey cohort represents an important resource to whales in that same year, which has potential implications for interpreting mid-late season whale abundance patterns. As well, a photo-identification study would be useful in characterizing whale residency patterns and determining whether the abundance trends reflect a relatively small subset of the regional population using the area for most of the season or a continuous flow of a larger portion of the population. Finally, similar analyses as those outlined here but conducted in other areas within the region would provide additional insight into the network’s capacity to support the recovering whale population. Title: Aspects of the foraging ecology of humpback whales (Megaptera novaeangliae) in Frederick Sound and Stephens Passage, Southeast Alaska Author: Szabo, Andrew, 1974- The North Pacific humpback whale (Megaptera novaeangliae) population has been increasing at an average annual rate of ~6% since the early 1990s. In northern Southeast Alaska alone, there are now more whales than estimated for the entire North Pacific several decades ago. An understanding of how this growing population is repopulating traditional foraging grounds will benefit from detailed investigations of their prey preferences and trends in whale abundance and distribution relative to those prey. This dissertation examines these issues from late May until early September 2008 in Frederick Sound and Stephens Passage, a Southeast Alaskan feeding area historically used by humpback whales. The foundation for the study is an analysis of the life histories and abundance patterns of euphausiids, the principal prey of humpbacks in the area, during late spring and summer. Four species, Thysanoessa raschii, T. longipes, T. spinifera, and Euphausia pacifica, were identified in plankton net samples collected at random locations throughout the study site (n = 49) and in locations where a strong scattering layer was observed on a 120 kHz echosounder (n = 48). Both sample types varied in euphausiid species composition. Abundance patterns of immature euphausiids coupled with observations of females carrying spermatophores indicated differences between species in spawning schedules. Thysanoessa spp. began spawning in early April with the spring phytoplankton bloom and continued until late June, whereas E. pacifica began spawning in early June and continued until late August. This protracted recruitment of immature euphausiids was geographically widespread throughout the summer in contrast to adults, which, although present all summer, were found primarily in slope and shallow (< 100 m) areas. To determine if humpback whales preferred one euphausiid species or life-stage over another, net sample and hydroacoustic data collected in the vicinity of whales were compared to similar data collected in random locations throughout the study site. This revealed that whales targeted dense aggregations of adult euphausiids, but did not discriminate between the various species, which was surprising because of presumed differences in the energy density linked to their different spawning schedules. Additionally, whales did not spend time in areas with concentrations of immature euphausiids, which were likely not large enough during the study period to be suitable prey. With this preference for adult euphausiids, the abundance and distribution patterns of humpbacks were examined in relation to prey availability. Whale abundance was lowest at the beginning of the study in late May at ca. 68 whales and peaked in late July at ca. 228 animals – approximately 12% of the region’s estimated abundance for the study year. This study did not detect a concomitant increase in the availability of adult euphausiids, which is unsurprising since immature euphausiids would not recruit into the adult population until after the end of the study, and post-spawning mortality and predation pressure is presumably high during this time. Instead, whales clustered increasingly around comparatively fewer prey as the summer progressed. These observations, combined with a plateau in whale abundance after July, suggest that their abundance in the area was limited by euphausiid availability. Estimates of whales using the study site during the summer have remained similar over several decades despite a dramatic increase in humpback numbers in Southeast Alaska and elsewhere in the North Pacific. The results from this study suggest that, although the study site remains important seasonally to some whales, it is not a significant source of prey responsible for regional population growth in general. More likely, it is part of a network of feeding areas that has influenced the population trend. Further insight into these and the other issues raised in this dissertation could come from several additional analyses. An extended sampling season that captures the recruitment of immature euphausiids into the adult population would reveal whether a given year's prey cohort represents an important resource to whales in that same year, which has potential implications for interpreting mid-late season whale abundance patterns. As well, a photo-identification study would be useful in characterizing whale residency patterns and determining whether the abundance trends reflect a relatively small subset of the regional population using the area for most of the season or a continuous flow of a larger portion of the population. Finally, similar analyses as those outlined here but conducted in other areas within the region would provide additional insight into the network’s capacity to support the recovering whale population. Close

• 386. [Article] Estimation and modeling of selected forest metrics with lidar and Landsat

  Lidar is able to provide height and cover information which can be used to estimate selected forest attributes precisely. However, for users to evaluate whether the additional cost and complication associated ...

  Citation × Citation Citation Abstract Copy Title: Estimation and modeling of selected forest metrics with lidar and Landsat Author: Strunk, Jacob L. Lidar is able to provide height and cover information which can be used to estimate selected forest attributes precisely. However, for users to evaluate whether the additional cost and complication associated with using Lidar merits adoption requires that the protocol to use lidar be thoroughly described and that a basis for selection of design parameters such as number of field plots and lidar pulse density be described. In our first analysis, we examine these issues by looking at the effects of pulse density and sample size on estimation when wall-to-wall lidar is used with a regression estimator. The effects were explored using resampling simulations. We examine both the effects on precision, and on the validity of inference. Pulse density had almost no effect on precision for the range examined, from 3 to .0625 pulses / m². The effect of sample size on estimator precision was roughly in accordance with the behavior indicated by the variance estimator, except that for small samples the variance estimator had positive bias (the variance estimates were too small), compromising the validity of inference. In future analyses we plan to provide further context for wall-to-wall lidar-assisted estimation. While there is a lot of literature on modeling, there is limited information on how lidar-assisted approaches compare to existing methods, and what variables can or cannot be acquired, or may be acquired with reduced confidence. We expand our investigation of estimation in our second analysis by examining lidar obtained in a sampling mode in combination with Landsat. In this case we make inference about the feasibility of a lidar-assisted estimation strategy by contrasting its variance estimate with variance estimates from a variety of other sampling designs and estimators. Of key interest was how the precision of a two-stage estimator with lidar strips compared with a plot-only estimator from a simple random sampling design. We found that because the long and narrow lidar strips incorporate much of the landscape variability, if the number of lidar strips was increased from 7 to 15 strips, the precision of estimators with lidar can exceed that of estimators applied to plot-only SRS data for a much larger number of plots. Increasing the number of lidar strips is considered to be highly viable since the costs of field plots can be quite expensive in Alaska, often exceeding the cost of a lidar strip. A Landsat-assisted approach used for either an SRS or a two-stage sample was also found to perform well relative to estimators for plot-only SRS data. This proved beneficial when we combined lidar and Landsat-assisted regression estimators for two-stage designs using a composite estimator. The composite estimator yielded much better results than either estimator used alone. We did not assess the effects of changing the number of lidar strips in combination with using a composite estimator, but this is an important analysis we plan to perform in a future study. In our final analysis we leverage the synergy between lidar and Landsat to improve the explanatory power of auxiliary Landsat using a multilevel modeling strategy. We also incorporate a more sophisticated approach to processing Landsat which reflects temporal trends in individual pixels values. Our approach used lidar as an intermediary step to better match the spatial resolution of Landsat and increase the proportion of area overlapped between measurement units for the different sources of data. We developed two separate approaches for two different resolutions of data (30 m and 90 m) using multiple modeling alternatives including OLS and k nearest neighbors (KNN), and found that both resolution and the modeling approach affected estimates of residual variability, although there was no combination of model types which was a clear winner for all responses. The modeling strategies generally fared better for the 90 m approaches, and future analyses will examine a broader range of resolutions. Fortunately the approaches used are fairly flexible and there is nothing prohibiting a 1000 m implementation. In the future we also plan to look at using a more sophisticated Landsat time-series approach. The current approach essentially dampened the noise in the temporal trend for a pixel, but did not make use of information in the trend such as slope or indications of disturbance – which may provide additional explanatory power. In a future study we will also incorporate a multilevel modeling into estimation or mapping strategies and evaluate the contribution of the multilevel modeling strategy relative to alternate approaches. Title: Estimation and modeling of selected forest metrics with lidar and Landsat Author: Strunk, Jacob L. Lidar is able to provide height and cover information which can be used to estimate selected forest attributes precisely. However, for users to evaluate whether the additional cost and complication associated with using Lidar merits adoption requires that the protocol to use lidar be thoroughly described and that a basis for selection of design parameters such as number of field plots and lidar pulse density be described. In our first analysis, we examine these issues by looking at the effects of pulse density and sample size on estimation when wall-to-wall lidar is used with a regression estimator. The effects were explored using resampling simulations. We examine both the effects on precision, and on the validity of inference. Pulse density had almost no effect on precision for the range examined, from 3 to .0625 pulses / m². The effect of sample size on estimator precision was roughly in accordance with the behavior indicated by the variance estimator, except that for small samples the variance estimator had positive bias (the variance estimates were too small), compromising the validity of inference. In future analyses we plan to provide further context for wall-to-wall lidar-assisted estimation. While there is a lot of literature on modeling, there is limited information on how lidar-assisted approaches compare to existing methods, and what variables can or cannot be acquired, or may be acquired with reduced confidence. We expand our investigation of estimation in our second analysis by examining lidar obtained in a sampling mode in combination with Landsat. In this case we make inference about the feasibility of a lidar-assisted estimation strategy by contrasting its variance estimate with variance estimates from a variety of other sampling designs and estimators. Of key interest was how the precision of a two-stage estimator with lidar strips compared with a plot-only estimator from a simple random sampling design. We found that because the long and narrow lidar strips incorporate much of the landscape variability, if the number of lidar strips was increased from 7 to 15 strips, the precision of estimators with lidar can exceed that of estimators applied to plot-only SRS data for a much larger number of plots. Increasing the number of lidar strips is considered to be highly viable since the costs of field plots can be quite expensive in Alaska, often exceeding the cost of a lidar strip. A Landsat-assisted approach used for either an SRS or a two-stage sample was also found to perform well relative to estimators for plot-only SRS data. This proved beneficial when we combined lidar and Landsat-assisted regression estimators for two-stage designs using a composite estimator. The composite estimator yielded much better results than either estimator used alone. We did not assess the effects of changing the number of lidar strips in combination with using a composite estimator, but this is an important analysis we plan to perform in a future study. In our final analysis we leverage the synergy between lidar and Landsat to improve the explanatory power of auxiliary Landsat using a multilevel modeling strategy. We also incorporate a more sophisticated approach to processing Landsat which reflects temporal trends in individual pixels values. Our approach used lidar as an intermediary step to better match the spatial resolution of Landsat and increase the proportion of area overlapped between measurement units for the different sources of data. We developed two separate approaches for two different resolutions of data (30 m and 90 m) using multiple modeling alternatives including OLS and k nearest neighbors (KNN), and found that both resolution and the modeling approach affected estimates of residual variability, although there was no combination of model types which was a clear winner for all responses. The modeling strategies generally fared better for the 90 m approaches, and future analyses will examine a broader range of resolutions. Fortunately the approaches used are fairly flexible and there is nothing prohibiting a 1000 m implementation. In the future we also plan to look at using a more sophisticated Landsat time-series approach. The current approach essentially dampened the noise in the temporal trend for a pixel, but did not make use of information in the trend such as slope or indications of disturbance – which may provide additional explanatory power. In a future study we will also incorporate a multilevel modeling into estimation or mapping strategies and evaluate the contribution of the multilevel modeling strategy relative to alternate approaches. Close

• 387. [Article] Resilience of large river basins : applying social-ecological systems theory, conflict management, and collaboration on the Mekong and Columbia Basins

  River basins provide essential services for both humans and ecosystems. Understanding the connections between ecosystems and society and their function has been at the heart of resilience studies and has ...

  Citation × Citation Citation Abstract Copy Title: Resilience of large river basins : applying social-ecological systems theory, conflict management, and collaboration on the Mekong and Columbia Basins Author: MacQuarrie, Patrick R. River basins provide essential services for both humans and ecosystems. Understanding the connections between ecosystems and society and their function has been at the heart of resilience studies and has become an increasing important endeavor in research and practice. In this dissertation, I define basin resilience as a river basin system's capacity to absorb, manage, and adapt to biophysical, social-economic, and political changes (or stressors) while still maintaining its essential structure, feedbacks, and functional integrity. I address the question of resilience, scale, and development in the Mekong and Columbia River Basins. This dissertation answers the following questions: 1) is systems theory an appropriate model to evaluate basin resilience, 2) is the Mekong Basin resilient, 3) are the Mekong and Columbia River Basins resilient across multiple scales, 4) can conflict management and collaborative learning enhance resilience, 5) can a resilience framework be used for basin comparisons, and 6) what lessons can the Mekong basin take from rapid development in the Columbia basin? In Chapter 2, I create and apply a social-ecological systems (SES) model of the Mekong River Basin to assess resilience at sub-basin (provincial), watershed (national), and basin (regional) scales. Feedbacks, thresholds, vulnerability, and adaptive capacity are determined and used as inputs into an overall basin resilience assessment. Drawing upon field work done in the Mekong Basin, Chapter 3 uses Conflict Management and Collaborative Learning processes to address resilience weaknesses across multiple scales in the Mekong Basin. Chapter 4 uses the basin resilience framework to compare the Mekong and Columbia Basins against physical characteristics, development rate, conflict and cooperation, and institutional responses to development projects. In this dissertation I find the Mekong has medium-low basin resilience and that scale is a critical determinant in basin resilience assessments. I find that in this study, vulnerability is inversely proportional to resilience, and low resilience at one scale, for example fisheries in the Tonle Sap Lake in Cambodia, decreases resilience for the entire basin. I find that Cambodia and Lao PDR are the least resilience and Thailand the most resilient countries in the Mekong Basin – Thailand more resilient in some sectors than the Mekong River Commission (MRC). I find that the MRC's conflict management strategy is hampered by a restrictive mandate and weakness in capacity building at tributary and national scales but that Collaborative Learning processes are effective in enhancing resilience at the sub-basin scale. Finally, I demonstrate through the basin comparison that the Mekong has a highly resilient biophysical system and traditionally a resilient institutional system however, the proposed rate of development is unsustainable with trends indicating a significant erosion of resilience. I find the Columbia Basin lacking resilience in fishing, hydropower, and water quality – sectors mitigating the effects of development in the Columbia Basin, manifesting as overall negative trends in cooperation. However, the Columbia shows signs of increasing cooperation due recent inclusion of Tribal Nations in water management. Flexible and inclusive institutional responses to water resource development challenges, in the Mekong to rapid development on the mainstream and in the Columbia to negotiations over renewal of the Columbia River Treaty, are key determinants to whether or not each basin can halt the current negative trends and strengthen basin resilience to face the challenges now and those coming in the future. Title: Resilience of large river basins : applying social-ecological systems theory, conflict management, and collaboration on the Mekong and Columbia Basins Author: MacQuarrie, Patrick R. River basins provide essential services for both humans and ecosystems. Understanding the connections between ecosystems and society and their function has been at the heart of resilience studies and has become an increasing important endeavor in research and practice. In this dissertation, I define basin resilience as a river basin system's capacity to absorb, manage, and adapt to biophysical, social-economic, and political changes (or stressors) while still maintaining its essential structure, feedbacks, and functional integrity. I address the question of resilience, scale, and development in the Mekong and Columbia River Basins. This dissertation answers the following questions: 1) is systems theory an appropriate model to evaluate basin resilience, 2) is the Mekong Basin resilient, 3) are the Mekong and Columbia River Basins resilient across multiple scales, 4) can conflict management and collaborative learning enhance resilience, 5) can a resilience framework be used for basin comparisons, and 6) what lessons can the Mekong basin take from rapid development in the Columbia basin? In Chapter 2, I create and apply a social-ecological systems (SES) model of the Mekong River Basin to assess resilience at sub-basin (provincial), watershed (national), and basin (regional) scales. Feedbacks, thresholds, vulnerability, and adaptive capacity are determined and used as inputs into an overall basin resilience assessment. Drawing upon field work done in the Mekong Basin, Chapter 3 uses Conflict Management and Collaborative Learning processes to address resilience weaknesses across multiple scales in the Mekong Basin. Chapter 4 uses the basin resilience framework to compare the Mekong and Columbia Basins against physical characteristics, development rate, conflict and cooperation, and institutional responses to development projects. In this dissertation I find the Mekong has medium-low basin resilience and that scale is a critical determinant in basin resilience assessments. I find that in this study, vulnerability is inversely proportional to resilience, and low resilience at one scale, for example fisheries in the Tonle Sap Lake in Cambodia, decreases resilience for the entire basin. I find that Cambodia and Lao PDR are the least resilience and Thailand the most resilient countries in the Mekong Basin – Thailand more resilient in some sectors than the Mekong River Commission (MRC). I find that the MRC's conflict management strategy is hampered by a restrictive mandate and weakness in capacity building at tributary and national scales but that Collaborative Learning processes are effective in enhancing resilience at the sub-basin scale. Finally, I demonstrate through the basin comparison that the Mekong has a highly resilient biophysical system and traditionally a resilient institutional system however, the proposed rate of development is unsustainable with trends indicating a significant erosion of resilience. I find the Columbia Basin lacking resilience in fishing, hydropower, and water quality – sectors mitigating the effects of development in the Columbia Basin, manifesting as overall negative trends in cooperation. However, the Columbia shows signs of increasing cooperation due recent inclusion of Tribal Nations in water management. Flexible and inclusive institutional responses to water resource development challenges, in the Mekong to rapid development on the mainstream and in the Columbia to negotiations over renewal of the Columbia River Treaty, are key determinants to whether or not each basin can halt the current negative trends and strengthen basin resilience to face the challenges now and those coming in the future. Close

• 388. [Article] Volcanic stratigraphy of the Deschutes Formation, Green Ridge to Fly Creek, north-central Oregon

  About 225 lava flows and ash-flow tuffs of the Deschutes Formation (DF) were mapped at Green Ridge. The units fill east-trending paleovalleys which "sky-out" westward and dip east; the eastward dip of ...

  Citation × Citation Citation Abstract Copy Title: Volcanic stratigraphy of the Deschutes Formation, Green Ridge to Fly Creek, north-central Oregon Author: Conrey, Richard M. About 225 lava flows and ash-flow tuffs of the Deschutes Formation (DF) were mapped at Green Ridge. The units fill east-trending paleovalleys which "sky-out" westward and dip east; the eastward dip of the units decreases as they are traced eastward. The source of the units was west of Green Ridge as evidenced by the increase in the number of ash-flow tuffs and lava flows in the DF from east to west toward Green Ridge, and the presence of viscous silicic lavas and lag deposits in ash-flow tuffs on the west flank of Green Ridge. The exposed DF section at Green Ridge is 1400 feet thick, and consists mainly of basaltic andesites with subordinate diktytaxitic basalts, andesites, dacites, aphyric basaltic andesites and andesites rich in Fe and Ti, ash-flow tuffs, and sediments. The upper 400 feet of the section is devoid of ash-flow tuffs and dacites. Nine paleomagnetic polarity intervals, five normal and four reversed, are recognized in the section; tentative correlation of these intervals with the magnetic time scale suggests that the oldest DF unit exposed at Green Ridge is 6.5 Ma, and the youngest 4.4 Ma. The DF units at the crest, and west of Green Ridge are cut by at least five N- to N13W-trending, down-to-the-west normal faults in a zone about five miles wide. These faults were possibly active as much as 5 Ma; the developing faults may have provided structural pathways for the ascent of the mafic lavas in the upper 400 feet of the section. The faulting which created the Green Ridge escarpment was probably finished by 3 Ma, and perhaps earlier. The presence of dense, Fe- and Ti-rich lavas throughout the DF section implies that magmas had relatively easy access to the surface during DF time (7.6-4.4 Ma), which suggests that the E-W extensional tectonism that culminated in the formation of the Green Ridge faults was present throughout deposition of the DF. The major element chemistry of DF diktytaxitic basalts, basaltic andesites, and andesites appears to change regularly with Ti02 content, as shown by decreasing CaO/FeO* (FeO* = total Fe expressed as FeO) with increasing Ti02, and by decreasing A1203 with increasing Ti02 at constant MgO content. The basalts and basaltic andesites with the lowest Ti02 contents also have the lowest alkali contents. These chemical trends appear to be caused by plagioclase, with subordinate olivine, fractionation, and are consistent with the fact that plagioclase and olivine are virtually the only phenocryst minerals in the mafic DF rocks. It is likely that the diktytaxitic basalt with the lowest Ti02 content is a parental magma. Fractionation may account for the chemical variations within the mafic rock groups considered separately, but the progression from basalt to andesite appears to be the result of mixing of silicic and mafic magmas. The chemistry of the rocks, especially the CaO/Al203 ratios, is consistent with such mixing, as is the petrography; opaque minerals are very late crystallizers in the basalts and basaltic andesites, and there is increasing evidence for magma mixing in the series basalt through andesite. Such evidence includes multiple plagioclase populations in the same rock, both of which are resorbed, and resorbed pyroxenes and amphiboles. Three flows of plagioclase megacryst-bearing basaltic andesite occur near the top of the DF section. The plagioclase megacrysts are up to 5 cm in length, commonly contain apatite inclusions, and resemble the plagioclase in anorthosite bodies. Ilmenite megacrysts are also present. The megacrysts and the presence of highly plagioclase-fractionated aphyric lavas rich in Fe and Ti in the DF suggest that anorthosite bodies are present beneath the north-central Oregon Cascade Range. Two xenoliths of partly melted cordierite-sillimanite-quartz granulite gneiss were found in a DF ash-flow tuff. The xenoliths demonstrate that granulite-grade metamorphism and at least local partial melting of the lower crust took place beneath the north-central Oregon Cascades. Title: Volcanic stratigraphy of the Deschutes Formation, Green Ridge to Fly Creek, north-central Oregon Author: Conrey, Richard M. About 225 lava flows and ash-flow tuffs of the Deschutes Formation (DF) were mapped at Green Ridge. The units fill east-trending paleovalleys which "sky-out" westward and dip east; the eastward dip of the units decreases as they are traced eastward. The source of the units was west of Green Ridge as evidenced by the increase in the number of ash-flow tuffs and lava flows in the DF from east to west toward Green Ridge, and the presence of viscous silicic lavas and lag deposits in ash-flow tuffs on the west flank of Green Ridge. The exposed DF section at Green Ridge is 1400 feet thick, and consists mainly of basaltic andesites with subordinate diktytaxitic basalts, andesites, dacites, aphyric basaltic andesites and andesites rich in Fe and Ti, ash-flow tuffs, and sediments. The upper 400 feet of the section is devoid of ash-flow tuffs and dacites. Nine paleomagnetic polarity intervals, five normal and four reversed, are recognized in the section; tentative correlation of these intervals with the magnetic time scale suggests that the oldest DF unit exposed at Green Ridge is 6.5 Ma, and the youngest 4.4 Ma. The DF units at the crest, and west of Green Ridge are cut by at least five N- to N13W-trending, down-to-the-west normal faults in a zone about five miles wide. These faults were possibly active as much as 5 Ma; the developing faults may have provided structural pathways for the ascent of the mafic lavas in the upper 400 feet of the section. The faulting which created the Green Ridge escarpment was probably finished by 3 Ma, and perhaps earlier. The presence of dense, Fe- and Ti-rich lavas throughout the DF section implies that magmas had relatively easy access to the surface during DF time (7.6-4.4 Ma), which suggests that the E-W extensional tectonism that culminated in the formation of the Green Ridge faults was present throughout deposition of the DF. The major element chemistry of DF diktytaxitic basalts, basaltic andesites, and andesites appears to change regularly with Ti02 content, as shown by decreasing CaO/FeO* (FeO* = total Fe expressed as FeO) with increasing Ti02, and by decreasing A1203 with increasing Ti02 at constant MgO content. The basalts and basaltic andesites with the lowest Ti02 contents also have the lowest alkali contents. These chemical trends appear to be caused by plagioclase, with subordinate olivine, fractionation, and are consistent with the fact that plagioclase and olivine are virtually the only phenocryst minerals in the mafic DF rocks. It is likely that the diktytaxitic basalt with the lowest Ti02 content is a parental magma. Fractionation may account for the chemical variations within the mafic rock groups considered separately, but the progression from basalt to andesite appears to be the result of mixing of silicic and mafic magmas. The chemistry of the rocks, especially the CaO/Al203 ratios, is consistent with such mixing, as is the petrography; opaque minerals are very late crystallizers in the basalts and basaltic andesites, and there is increasing evidence for magma mixing in the series basalt through andesite. Such evidence includes multiple plagioclase populations in the same rock, both of which are resorbed, and resorbed pyroxenes and amphiboles. Three flows of plagioclase megacryst-bearing basaltic andesite occur near the top of the DF section. The plagioclase megacrysts are up to 5 cm in length, commonly contain apatite inclusions, and resemble the plagioclase in anorthosite bodies. Ilmenite megacrysts are also present. The megacrysts and the presence of highly plagioclase-fractionated aphyric lavas rich in Fe and Ti in the DF suggest that anorthosite bodies are present beneath the north-central Oregon Cascade Range. Two xenoliths of partly melted cordierite-sillimanite-quartz granulite gneiss were found in a DF ash-flow tuff. The xenoliths demonstrate that granulite-grade metamorphism and at least local partial melting of the lower crust took place beneath the north-central Oregon Cascades. Close

• 389. [Article] Evaluation of mountain pine beetle infestations, Lap, Cool, Lang, and Caribou Creek drainages, Yaak Ranger District, Kootenai National Forest, Montana

  Mountain pine beetle reached epidemic levels in the Lap, Cool, Lang, and Caribou Creek drainages in 1974. From 1973 to 1975, approximately 56,282 trees with an estimated volume of 4,365,660 board feet ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of mountain pine beetle infestations, Lap, Cool, Lang, and Caribou Creek drainages, Yaak Ranger District, Kootenai National Forest, Montana Author: McGregor, Mark D., Hamel, Dennis R., United States. Forest Service. Northern Region. State & Private Forestry Mountain pine beetle reached epidemic levels in the Lap, Cool, Lang, and Caribou Creek drainages in 1974. From 1973 to 1975, approximately 56,282 trees with an estimated volume of 4,365,660 board feet were killed in these areas. An additional 61,721 trees are predicted to be killed in 1976. Currently infested acreage on the Yaak Ranger District equals 5,110 ac. (2,068 ha), This represents 5% of the 118,345 ac. (47,894 ha) risk rated high and given Priority 1 for management treatment. Selective logging to remove infested and susceptible trees is recommended to reduce the epidemic trend. Title: Evaluation of mountain pine beetle infestations, Lap, Cool, Lang, and Caribou Creek drainages, Yaak Ranger District, Kootenai National Forest, Montana Author: McGregor, Mark D., Hamel, Dennis R., United States. Forest Service. Northern Region. State & Private Forestry Mountain pine beetle reached epidemic levels in the Lap, Cool, Lang, and Caribou Creek drainages in 1974. From 1973 to 1975, approximately 56,282 trees with an estimated volume of 4,365,660 board feet were killed in these areas. An additional 61,721 trees are predicted to be killed in 1976. Currently infested acreage on the Yaak Ranger District equals 5,110 ac. (2,068 ha), This represents 5% of the 118,345 ac. (47,894 ha) risk rated high and given Priority 1 for management treatment. Selective logging to remove infested and susceptible trees is recommended to reduce the epidemic trend. Close

• 390. [Article] Control of the western pine shoot borer Eucosma sonomana kearfott in selected ponderosa pine plantations in northern Idaho and western Montana : progress report no. 2

  Two blends (Natural and Phillips) of the western pine shoot borer pheromone, formulated as Hercon Luretape, were applied to six ponderosa pine plantations in northern Idaho and western Montana in 1984. ...

  Citation × Citation Citation Abstract Copy Title: Control of the western pine shoot borer Eucosma sonomana kearfott in selected ponderosa pine plantations in northern Idaho and western Montana : progress report no. 2 Author: Dewey, Jerald E., United States. Forest Service. Northern Region. State & Private Forestry Two blends (Natural and Phillips) of the western pine shoot borer pheromone, formulated as Hercon Luretape, were applied to six ponderosa pine plantations in northern Idaho and western Montana in 1984. The treatment was approximately 21.6 grams of pheromone per hectare. Significant reductions in damage have occurred in all treated plantations. Damage has been reduced most in plantations that are not surrounded by pine stands which provide a reservoir of moths that can reinvade treated areas. The best results to date have been a reduction of infested terminals from 50.9 to 1.6 percent after 2 years of treatment. Population trends in nearby check areas were either static or increasing. Treatment effects of both the Natural and Phillips formulations were significantly different from the control at the 99 percent level. However, these treatments were not different from each other. Title: Control of the western pine shoot borer Eucosma sonomana kearfott in selected ponderosa pine plantations in northern Idaho and western Montana : progress report no. 2 Author: Dewey, Jerald E., United States. Forest Service. Northern Region. State & Private Forestry Two blends (Natural and Phillips) of the western pine shoot borer pheromone, formulated as Hercon Luretape, were applied to six ponderosa pine plantations in northern Idaho and western Montana in 1984. The treatment was approximately 21.6 grams of pheromone per hectare. Significant reductions in damage have occurred in all treated plantations. Damage has been reduced most in plantations that are not surrounded by pine stands which provide a reservoir of moths that can reinvade treated areas. The best results to date have been a reduction of infested terminals from 50.9 to 1.6 percent after 2 years of treatment. Population trends in nearby check areas were either static or increasing. Treatment effects of both the Natural and Phillips formulations were significantly different from the control at the 99 percent level. However, these treatments were not different from each other. Close