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• 681. [Article] Characterization of the California Live Bait Fishery

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Characterization of the California Live Bait Fishery Author: Hilger, James Abstract only. Title: Characterization of the California Live Bait Fishery Author: Hilger, James Abstract only. Close

• 682. [Article] Kinetic characterization of the soluble butane monooxygenase from Thauera butanivorans, formerly ‘Pseudomonas butanovora’

  Copyrighted by the Society for General Microbiology

  Citation × Citation Citation Abstract Copy Title: Kinetic characterization of the soluble butane monooxygenase from Thauera butanivorans, formerly ‘Pseudomonas butanovora’ Author: Sayavedra-Soto, Luis A., Arp, Daniel J., Bottomley, Peter J., Cooley, Richard B., Dubbels, Bradley L. Copyrighted by the Society for General Microbiology Title: Kinetic characterization of the soluble butane monooxygenase from Thauera butanivorans, formerly ‘Pseudomonas butanovora’ Author: Sayavedra-Soto, Luis A., Arp, Daniel J., Bottomley, Peter J., Cooley, Richard B., Dubbels, Bradley L. Copyrighted by the Society for General Microbiology Close

• 683. [Article] The effect of chronic exposure of chinook salmon to benzo(a)pyrene and cortisol of CYP1A1 induction and susceptibility to a microsporidian parasite, Loma salmonae

  Wild populations of fish are faced with a multitude of stressors, which may include human interaction, toxins, and disease. Benzo(a)pyrene (BaP), a known carcinogen and immunotoxin, has been reported in ...

  Citation × Citation Citation Abstract Copy Title: The effect of chronic exposure of chinook salmon to benzo(a)pyrene and cortisol of CYP1A1 induction and susceptibility to a microsporidian parasite, Loma salmonae Author: Marie, Amarisa Wild populations of fish are faced with a multitude of stressors, which may include human interaction, toxins, and disease. Benzo(a)pyrene (BaP), a known carcinogen and immunotoxin, has been reported in the stomach contents of juvenile chinook salmon, Oncorhynchus tshawytscha, in urban waterways. We investigated the impact of chronic dietary exposure of environmentally relevant levels of BaP on the immune system and cytochrome P4501A1 (CYP1A1) expression in juvenile chinook salmon. Two experiments were carried out in which juvenile fish were fed food treated with ethanol (control diet), low or high concentrations of BaP, or cortisol. In the first experiment we measured mitogen-stimulated proliferation of splenic leukocytes using flow cytometry and a colorimetric assay using Alamar Blue[superscript TM] Susceptibility to a microsporidian parasite, Loma salmonae, was evaluated in the second experiment by quantification of xenomas in the gills. Hepatic CYP1A1 and plasma cortisol were measured in both experiments. No significant trends were found in leukocyte mitogen activation or plasma cortisol between treatments or days. However, western blot analysis of CYP1A1 concentration in liver revealed interesting patterns of induction: in cortisol fed groups CYP1A1 was <20% of control on all days, groups fed low levels of BaP were 250% of control values on days 8 and 21 then dropped below control values on day 29, and groups fed high levels of BaP had less CYP1A1 than controls on all days. Similar patterns of CYP1A1 levels were found in the second experiment, and diseased control groups showed about a 55% decrease in CYP1A1 concentration when compared with non-diseased control groups. Susceptibility to L. salmonae was significantly higher in groups receiving cortisol. Whereas there was no effect of the high BaP dose, the low BaP dose appeared to increase disease susceptibility. This study supports concerns of stress and toxin induced immune dysfunction in wild populations of fish. Title: The effect of chronic exposure of chinook salmon to benzo(a)pyrene and cortisol of CYP1A1 induction and susceptibility to a microsporidian parasite, Loma salmonae Author: Marie, Amarisa Wild populations of fish are faced with a multitude of stressors, which may include human interaction, toxins, and disease. Benzo(a)pyrene (BaP), a known carcinogen and immunotoxin, has been reported in the stomach contents of juvenile chinook salmon, Oncorhynchus tshawytscha, in urban waterways. We investigated the impact of chronic dietary exposure of environmentally relevant levels of BaP on the immune system and cytochrome P4501A1 (CYP1A1) expression in juvenile chinook salmon. Two experiments were carried out in which juvenile fish were fed food treated with ethanol (control diet), low or high concentrations of BaP, or cortisol. In the first experiment we measured mitogen-stimulated proliferation of splenic leukocytes using flow cytometry and a colorimetric assay using Alamar Blue[superscript TM] Susceptibility to a microsporidian parasite, Loma salmonae, was evaluated in the second experiment by quantification of xenomas in the gills. Hepatic CYP1A1 and plasma cortisol were measured in both experiments. No significant trends were found in leukocyte mitogen activation or plasma cortisol between treatments or days. However, western blot analysis of CYP1A1 concentration in liver revealed interesting patterns of induction: in cortisol fed groups CYP1A1 was <20% of control on all days, groups fed low levels of BaP were 250% of control values on days 8 and 21 then dropped below control values on day 29, and groups fed high levels of BaP had less CYP1A1 than controls on all days. Similar patterns of CYP1A1 levels were found in the second experiment, and diseased control groups showed about a 55% decrease in CYP1A1 concentration when compared with non-diseased control groups. Susceptibility to L. salmonae was significantly higher in groups receiving cortisol. Whereas there was no effect of the high BaP dose, the low BaP dose appeared to increase disease susceptibility. This study supports concerns of stress and toxin induced immune dysfunction in wild populations of fish. Close

• 684. [Article] Perspectives from the ranching culture in the 1990's : addressing mythological and environmental concerns

  Ideals of freedom, independence, and land ownership helped form and perpetuate the mythology of ranching in the United States. However, stereotypes emerged as a result of distortion from the media and ...

  Citation × Citation Citation Abstract Copy Title: Perspectives from the ranching culture in the 1990's : addressing mythological and environmental concerns Author: Steward, Judith A. Ideals of freedom, independence, and land ownership helped form and perpetuate the mythology of ranching in the United States. However, stereotypes emerged as a result of distortion from the media and the move away from the land. Social philosophies changed regarding the environment, land use, and the health and safety of the food supply in the late 20th century. In relation to the mythology, stereotype, and social theory regarding the ranching culture, this research seeks to clarify the fundamental principles, business philosophy, lifestyle, and values of men and women raising beef as a food product on both public and private lands in the 1990's. The mythology surrounding ranchers and cowboys are the result of three historical periods in the United States; however, the last 100 years have had the most profound effect in developing stereotypes. In this survey, 42 ranchers in Lake County, Oregon and Modoc County, California describe the challenges, satisfactions, and the partnership with Nature that is part of their livelihood in the harsh, high desert environment of eastern Oregon and northeastern California. The low ratio of private ground in these counties creates a dependency on use of public lands for grazing. This use if often stereotyped as "welfare ranching," without computation for other variables that make it comparable with private leasing. Historically, the Taylor Grazing Act authorizes fee grazing between ranchers and the U.S. government, but current philosophy has shifted its view of free enterprise on public lands, terming it "resource extraction." Although ranching is high in risk and low in economic return, ranchers stay in the business because they value freedom, hard work, family cohesiveness, and the interaction with Nature and the land. The future of ranching is challenged by environmental policy, government agency relations, public opinion, the high cost of land and production, and a lack of unity in the beef industry. To survive, ranchers need to unify, sharpen communication skills, provide education about ranching practices to the public, and become service-oriented as an organization to change stereotype and meet the social criteria of the next century. Title: Perspectives from the ranching culture in the 1990's : addressing mythological and environmental concerns Author: Steward, Judith A. Ideals of freedom, independence, and land ownership helped form and perpetuate the mythology of ranching in the United States. However, stereotypes emerged as a result of distortion from the media and the move away from the land. Social philosophies changed regarding the environment, land use, and the health and safety of the food supply in the late 20th century. In relation to the mythology, stereotype, and social theory regarding the ranching culture, this research seeks to clarify the fundamental principles, business philosophy, lifestyle, and values of men and women raising beef as a food product on both public and private lands in the 1990's. The mythology surrounding ranchers and cowboys are the result of three historical periods in the United States; however, the last 100 years have had the most profound effect in developing stereotypes. In this survey, 42 ranchers in Lake County, Oregon and Modoc County, California describe the challenges, satisfactions, and the partnership with Nature that is part of their livelihood in the harsh, high desert environment of eastern Oregon and northeastern California. The low ratio of private ground in these counties creates a dependency on use of public lands for grazing. This use if often stereotyped as "welfare ranching," without computation for other variables that make it comparable with private leasing. Historically, the Taylor Grazing Act authorizes fee grazing between ranchers and the U.S. government, but current philosophy has shifted its view of free enterprise on public lands, terming it "resource extraction." Although ranching is high in risk and low in economic return, ranchers stay in the business because they value freedom, hard work, family cohesiveness, and the interaction with Nature and the land. The future of ranching is challenged by environmental policy, government agency relations, public opinion, the high cost of land and production, and a lack of unity in the beef industry. To survive, ranchers need to unify, sharpen communication skills, provide education about ranching practices to the public, and become service-oriented as an organization to change stereotype and meet the social criteria of the next century. Close

• 685. [Article] Eclipse Ice Core Accumulation and Stable Isotope Variability as an Indicator of North Pacific Climate

  This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://www.ametsoc.org/pubs/journals/jcli/.

  Citation × Citation Citation Abstract Copy Title: Eclipse Ice Core Accumulation and Stable Isotope Variability as an Indicator of North Pacific Climate Author: Kreutz, Karl, Yalcin, Kaplan, Wake, Cameron P., Kelsey, Eric P. This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://www.ametsoc.org/pubs/journals/jcli/. Title: Eclipse Ice Core Accumulation and Stable Isotope Variability as an Indicator of North Pacific Climate Author: Kreutz, Karl, Yalcin, Kaplan, Wake, Cameron P., Kelsey, Eric P. This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://www.ametsoc.org/pubs/journals/jcli/. Close

• 686. [Article] CAM : a new Circuit Augmentation Method for modeling interconnects and passive components

  Contemporary circuit design involves significant computer-based simulation, calling for a balance between circuit model accuracy and simulation run time. Traditionally, circuit modelers concentrated on ...

  Citation × Citation Citation Abstract Copy Title: CAM : a new Circuit Augmentation Method for modeling interconnects and passive components Author: Kolstad, Joel W. Contemporary circuit design involves significant computer-based simulation, calling for a balance between circuit model accuracy and simulation run time. Traditionally, circuit modelers concentrated on producing either (1) physically-based models, where each element in the model correlates to a physically meaningful aspect of the device being modeled or (2) mathematically-based "macromodels," designed to be efficient to simulate without ties to the device's physical underpinnings. While each approach has significant value, the strengths of one are often the weaknesses of the other. This work presents CAM, the Circuit Augmentation Method, that integrates some of the best aspects of each approach. Based on the assumption that high-accuracy, multi-port simulation or measurement data for the device under consideration is available, the methodology augments an existing, user-provided equivalent circuit model that is reasonably accurate over some frequency band with discrepancies elsewhere. Macromodels using rational functions are derived via standard least-squares or vector fittings approaches and are logically "added" to the user model creating a result that is potentially both fast to simulate yet still physically meaningful. An important aspect of CAM is its perturbational nature: It is shown that perturbation of the user model's component values (or similar attributes) is necessary for optimal results. CAM is a general-purpose technique that is applicable to the often difficult problems of modeling circuits requiring wideband accuracy or those incorporating highly-distributed structures. This utility is demonstrated over several two-port examples, including a broadband oscilloscope probe tip, a spiral inductor on a lossy silicon substrate, and a highly-distributed and lossy test circuit. Title: CAM : a new Circuit Augmentation Method for modeling interconnects and passive components Author: Kolstad, Joel W. Contemporary circuit design involves significant computer-based simulation, calling for a balance between circuit model accuracy and simulation run time. Traditionally, circuit modelers concentrated on producing either (1) physically-based models, where each element in the model correlates to a physically meaningful aspect of the device being modeled or (2) mathematically-based "macromodels," designed to be efficient to simulate without ties to the device's physical underpinnings. While each approach has significant value, the strengths of one are often the weaknesses of the other. This work presents CAM, the Circuit Augmentation Method, that integrates some of the best aspects of each approach. Based on the assumption that high-accuracy, multi-port simulation or measurement data for the device under consideration is available, the methodology augments an existing, user-provided equivalent circuit model that is reasonably accurate over some frequency band with discrepancies elsewhere. Macromodels using rational functions are derived via standard least-squares or vector fittings approaches and are logically "added" to the user model creating a result that is potentially both fast to simulate yet still physically meaningful. An important aspect of CAM is its perturbational nature: It is shown that perturbation of the user model's component values (or similar attributes) is necessary for optimal results. CAM is a general-purpose technique that is applicable to the often difficult problems of modeling circuits requiring wideband accuracy or those incorporating highly-distributed structures. This utility is demonstrated over several two-port examples, including a broadband oscilloscope probe tip, a spiral inductor on a lossy silicon substrate, and a highly-distributed and lossy test circuit. Close

• 687. [Article] A study of feeding value and potential toxicity of pulp mill single cell protein in ruminants

  The objectives of this study were to evaluate the feeding value and potential toxicity of single cell protein (SCP) when fed to ruminants. Three in vivo digestibility trials with lambs, one feedlot trial with ...

  Citation × Citation Citation Abstract Copy Title: A study of feeding value and potential toxicity of pulp mill single cell protein in ruminants Author: Atil, Osman Bin The objectives of this study were to evaluate the feeding value and potential toxicity of single cell protein (SCP) when fed to ruminants. Three in vivo digestibility trials with lambs, one feedlot trial with steers and one long term feeding trial of high levels of SCP with sheep were conducted to accomplish the objectives of this study. The in vivo digestibility trial with lambs showed that the SCP was utilized efficiently by the lambs at both 50 and 100% crude protein (CP) replacements of cottonseed meal (CSM). Supplementation of urea in the presence of SCP tended to increase (P<.05) the digestibility coefficients of the dietary nutrients. Performance of the feedlot steers fed increased levels of CP supplementation from SCP were similar (P>.05) to CSM supplemented steers. There were increased (P<.05) Cd concentrations in the liver and spleen of steers fed with SCP protein supplementations. There were no toxicity problems due to any heavy metals present in the.SCP. Histological examinations further revealed no uncommon pathological signs in liver, kidney or muscle of the steers. The long term feeding of growing sheep showed a significant increase of Cd concentrations in the liver (.445 and .614 ppm) and kidney (1.286 and 1.236 ppm) of sheep that were fed with Grays Harbor and Port Angeles SCP. Significant amounts of Pb (1.421 ppm) were found in the liver of sheep that were fed with Port Angeles SCP. However, the levels of Cd and Pb concentrated in these tissues were not considered too high to cause any ill effect to the sheep or to humans as a major consumer of animal products. Performance of the sheep throughout the experimental period was normal except for severe diarrhea in the group fed high levels of polyacrylamide which was used to concentrate the SCP during the drying process. Title: A study of feeding value and potential toxicity of pulp mill single cell protein in ruminants Author: Atil, Osman Bin The objectives of this study were to evaluate the feeding value and potential toxicity of single cell protein (SCP) when fed to ruminants. Three in vivo digestibility trials with lambs, one feedlot trial with steers and one long term feeding trial of high levels of SCP with sheep were conducted to accomplish the objectives of this study. The in vivo digestibility trial with lambs showed that the SCP was utilized efficiently by the lambs at both 50 and 100% crude protein (CP) replacements of cottonseed meal (CSM). Supplementation of urea in the presence of SCP tended to increase (P<.05) the digestibility coefficients of the dietary nutrients. Performance of the feedlot steers fed increased levels of CP supplementation from SCP were similar (P>.05) to CSM supplemented steers. There were increased (P<.05) Cd concentrations in the liver and spleen of steers fed with SCP protein supplementations. There were no toxicity problems due to any heavy metals present in the.SCP. Histological examinations further revealed no uncommon pathological signs in liver, kidney or muscle of the steers. The long term feeding of growing sheep showed a significant increase of Cd concentrations in the liver (.445 and .614 ppm) and kidney (1.286 and 1.236 ppm) of sheep that were fed with Grays Harbor and Port Angeles SCP. Significant amounts of Pb (1.421 ppm) were found in the liver of sheep that were fed with Port Angeles SCP. However, the levels of Cd and Pb concentrated in these tissues were not considered too high to cause any ill effect to the sheep or to humans as a major consumer of animal products. Performance of the sheep throughout the experimental period was normal except for severe diarrhea in the group fed high levels of polyacrylamide which was used to concentrate the SCP during the drying process. Close

• 688. [Article] A Hierarchy of Models for Simulating Experimental Results 6 from a 3D Heterogeneous Porous Medium

  In this work we examine the dispersion of conservative tracers (bromide and fluorescein) in an experimentally constructed three-dimensional dual-porosity porous medium, and in the absence of adjustable ...

  Citation × Citation Citation Abstract Copy Title: A Hierarchy of Models for Simulating Experimental Results 6 from a 3D Heterogeneous Porous Medium Author: Ostvar, Sassan, Wood, Brian D., Paustian, Rebecca, Vogler, Daniel In this work we examine the dispersion of conservative tracers (bromide and fluorescein) in an experimentally constructed three-dimensional dual-porosity porous medium, and in the absence of adjustable parameters. The medium is highly heterogeneous (σ2 Y = 5.7), and consists of spherical, low-hydraulic-conductivity inclusions embedded in a high-hydraulic-conductivity matrix. The bi-modal medium was saturated with tracers, and then flushed with tracer-free fluid while the effluent breakthrough curves were measured. The focus for this work is to examine a hierarchy of decreasingly complex models to assess their ability to accurately represent the measured breakthrough curves. The most information-rich model was a direct numerical simulation of the system in which the geometry, boundary and initial conditions, and medium properties were fully independently characterized experimentally with high fidelity. The reduced models included (1) a simplified numerical model identical to the fully-resolved DNS model, but using a domain that was one-tenth the size; (2) an upscaled mobile-immobile model that allowed for a time-dependent mass-transfer coefficient; and, (3) an upscaled mobile-immobile model that assumed a space-time constant mass-transfer coefficient. The results illustrated that all four models provided accurate representations of the experimental breakthrough curves as measured by global RMS error. The primary component of error induced in the upscaled models appeared to arise from the neglect of convection within the inclusions. We discuss the necessity to assign value (via a utility function or other similar method) to assign value to outcomes if one is to further select from among model options. Title: A Hierarchy of Models for Simulating Experimental Results 6 from a 3D Heterogeneous Porous Medium Author: Ostvar, Sassan, Wood, Brian D., Paustian, Rebecca, Vogler, Daniel In this work we examine the dispersion of conservative tracers (bromide and fluorescein) in an experimentally constructed three-dimensional dual-porosity porous medium, and in the absence of adjustable parameters. The medium is highly heterogeneous (σ2 Y = 5.7), and consists of spherical, low-hydraulic-conductivity inclusions embedded in a high-hydraulic-conductivity matrix. The bi-modal medium was saturated with tracers, and then flushed with tracer-free fluid while the effluent breakthrough curves were measured. The focus for this work is to examine a hierarchy of decreasingly complex models to assess their ability to accurately represent the measured breakthrough curves. The most information-rich model was a direct numerical simulation of the system in which the geometry, boundary and initial conditions, and medium properties were fully independently characterized experimentally with high fidelity. The reduced models included (1) a simplified numerical model identical to the fully-resolved DNS model, but using a domain that was one-tenth the size; (2) an upscaled mobile-immobile model that allowed for a time-dependent mass-transfer coefficient; and, (3) an upscaled mobile-immobile model that assumed a space-time constant mass-transfer coefficient. The results illustrated that all four models provided accurate representations of the experimental breakthrough curves as measured by global RMS error. The primary component of error induced in the upscaled models appeared to arise from the neglect of convection within the inclusions. We discuss the necessity to assign value (via a utility function or other similar method) to assign value to outcomes if one is to further select from among model options. Close

• 689. [Article] Cretaceous-to-recent record of elevated ³He/⁴He along the Hawaiian-Emperor volcanic chain

  Copyrighted by American Geophysical Union.

  Citation × Citation Citation Abstract Copy Title: Cretaceous-to-recent record of elevated ³He/⁴He along the Hawaiian-Emperor volcanic chain Author: Keller, R. A., Lupton, J. E., Duncan, Robert A., Farley, K. A., Graham, David W. Copyrighted by American Geophysical Union. Title: Cretaceous-to-recent record of elevated ³He/⁴He along the Hawaiian-Emperor volcanic chain Author: Keller, R. A., Lupton, J. E., Duncan, Robert A., Farley, K. A., Graham, David W. Copyrighted by American Geophysical Union. Close

• 690. [Article] Forage production and utilization in relation to deer browsing of Douglas-fir seedlings in the Tillamook Burn, Oregon

  The main objective of this investigation was to evaluate relationships between the production and utilization of forage and deer browsing of hand-planted Douglas-fir seedlings. A secondary purpose was ...

  Citation × Citation Citation Abstract Copy Title: Forage production and utilization in relation to deer browsing of Douglas-fir seedlings in the Tillamook Burn, Oregon Author: Crouch, Glenn Leroy, 1929- The main objective of this investigation was to evaluate relationships between the production and utilization of forage and deer browsing of hand-planted Douglas-fir seedlings. A secondary purpose was to study some effects of selected physical and biological site factors on the survival and growth of fir seedlings. Field work was undertaken between June, 1961, and February, 1964, in a 340-acre deer-tight enclosure used by known numbers of deer since 1959. The study area located on steep topography in the Tillamook Burn of northwest Oregon was subjected to three wildfires between 1933 and 1945 destroying all coniferous forest growth. Since 1945, a large portion of the enclosure area has been highly disturbed by erosion and salvage logging operations. Present vegetation consists mainly of seral species which have been classified into six plant communities. Vegetation studies showed that overstory plant cover averaged about l2 percent and understory cover 77 percent in the summer of 1963. Yields of summer forage averaged 2,600 pounds per acre, and forage available for winter use averaged 640 pounds per acre on September 1. Subsequent weathering losses and deer utilization greatly reduced the latter value by mid-winter. Growth of winter-active herbaceous forage was approximately 90 pounds per acre in March, and by May, normal forage supplies were again available. From winter browsing trials, utilization studies, and examinations of deer stomachs it was concluded that: Blackberry leaves were the most highly preferred forage during the winter season. Salal ranked high but was limited in distribution. Huckleberry and cascara were preferred woody plants whereas alder, hazel, and vine maple were utilized only when herbaceous forage was unavailable. Planted Douglas-fir occupied a prominent place on the food preference list, ranking higher than most common woody plants. Winter-active herbaceous forage was highly important in winter and early spring diets. Leaves of herbaceous and woody plants supplied nearly all the summer forage and were important in all seasons when available. Browsing of Douglas-fir seedlings began at lower elevations when the enclosure was first covered with snow. Later it occurred at all levels but was concentrated on lower areas. Chemical analyses of forage samples collected through the year indicated that blackberry was the most nutritious forage plant commonly eaten by deer. Leaf material from other plants was highly nutritious but twigs of the same species generally provided poor quality forage. Winter-active grasses and herbs were highly nutritious but an excessive moisture content reduced their unit-intake value. Douglas-fir was higher in nutrient content than most woody plants and rated as good feed when herbaceous forage was unavailable. Forage preference appeared to be positively related to nutrient content in a majority of the plants which were compared. Notable exceptions were alder in the winter season and huckleberry during most of the year. Artificial rumen analyses revealed that all forages were lower in digestibility than alfalfa pellets. In general, digestibility seemed to be related to forage preference. Green leafy feeds were more highly digested than woody twigs. The incidence of Douglas-fir browsing was found to be significantly related to several physical and biological site variables. It was concluded that Douglas-fir browsing will continue unless or until seedlings are completely protected from deer by physical or physiological (chemical) isolation because fir seedlings are an important source of forage during certain periods of the winter season. Title: Forage production and utilization in relation to deer browsing of Douglas-fir seedlings in the Tillamook Burn, Oregon Author: Crouch, Glenn Leroy, 1929- The main objective of this investigation was to evaluate relationships between the production and utilization of forage and deer browsing of hand-planted Douglas-fir seedlings. A secondary purpose was to study some effects of selected physical and biological site factors on the survival and growth of fir seedlings. Field work was undertaken between June, 1961, and February, 1964, in a 340-acre deer-tight enclosure used by known numbers of deer since 1959. The study area located on steep topography in the Tillamook Burn of northwest Oregon was subjected to three wildfires between 1933 and 1945 destroying all coniferous forest growth. Since 1945, a large portion of the enclosure area has been highly disturbed by erosion and salvage logging operations. Present vegetation consists mainly of seral species which have been classified into six plant communities. Vegetation studies showed that overstory plant cover averaged about l2 percent and understory cover 77 percent in the summer of 1963. Yields of summer forage averaged 2,600 pounds per acre, and forage available for winter use averaged 640 pounds per acre on September 1. Subsequent weathering losses and deer utilization greatly reduced the latter value by mid-winter. Growth of winter-active herbaceous forage was approximately 90 pounds per acre in March, and by May, normal forage supplies were again available. From winter browsing trials, utilization studies, and examinations of deer stomachs it was concluded that: Blackberry leaves were the most highly preferred forage during the winter season. Salal ranked high but was limited in distribution. Huckleberry and cascara were preferred woody plants whereas alder, hazel, and vine maple were utilized only when herbaceous forage was unavailable. Planted Douglas-fir occupied a prominent place on the food preference list, ranking higher than most common woody plants. Winter-active herbaceous forage was highly important in winter and early spring diets. Leaves of herbaceous and woody plants supplied nearly all the summer forage and were important in all seasons when available. Browsing of Douglas-fir seedlings began at lower elevations when the enclosure was first covered with snow. Later it occurred at all levels but was concentrated on lower areas. Chemical analyses of forage samples collected through the year indicated that blackberry was the most nutritious forage plant commonly eaten by deer. Leaf material from other plants was highly nutritious but twigs of the same species generally provided poor quality forage. Winter-active grasses and herbs were highly nutritious but an excessive moisture content reduced their unit-intake value. Douglas-fir was higher in nutrient content than most woody plants and rated as good feed when herbaceous forage was unavailable. Forage preference appeared to be positively related to nutrient content in a majority of the plants which were compared. Notable exceptions were alder in the winter season and huckleberry during most of the year. Artificial rumen analyses revealed that all forages were lower in digestibility than alfalfa pellets. In general, digestibility seemed to be related to forage preference. Green leafy feeds were more highly digested than woody twigs. The incidence of Douglas-fir browsing was found to be significantly related to several physical and biological site variables. It was concluded that Douglas-fir browsing will continue unless or until seedlings are completely protected from deer by physical or physiological (chemical) isolation because fir seedlings are an important source of forage during certain periods of the winter season. Close