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• 2521. [Article] The Effect of Road Investment on Economic Development: A Case Study of the Oregon Counties

  Despite its significance and frequent mentioning in the literature, the relationship between road investment and economic development has never been clearly understood. A significant number of scholars ...

  Citation × Citation Citation Abstract Copy Title: The Effect of Road Investment on Economic Development: A Case Study of the Oregon Counties Author: Al-Alwan, Ameer Mohammed Year: 1991 Despite its significance and frequent mentioning in the literature, the relationship between road investment and economic development has never been clearly understood. A significant number of scholars in this field have always emphasized the need for further research to examine this complex and dynamic relationship. Historically, investment in transportation networks has played a great role in the development of cities, regions, and nations. This positive view is attributed to the indispensable role that water transportation, and then rail transport, played in the early development of Europe and the United States. In recent years, many scholars, as well as policy makers, have disputed that investment in transportation, and in particular roads, in the regions of a highly developed country like the United States will have a great impact on economic development. This disagreement and speculation about the role of transportation investment, especially roads which constitute a large portion of the transportation network, on economic development has made justification for roads funding difficult. This is coupled with the recent decline in federal funding for many civilian programs, and in particular, regional economic development program, that include investment in road systems. Furthermore, rising construction and maintenance costs for major highway systems have substantially out-paced the current funding levels. As a result of the shortage of roads funding and the lack of federal support, individual states have started to take on more responsibility for keeping their road network intact. In almost all the states in the nation, and Oregon is no exception, the state Departments of Transportation have started to use economic development as a criterion for roads funding. Therefore, it is the objective of this dissertation to examine the longitudinal impact of the various types of roads investments on economic development in Oregon in order to better understand this dynamic relationship. Total road expenditures, capital expenditures in the three types of roads (primary, secondary, and local), total maintenance expenditures, and maintenance expenditures in the three types of roads are used as a measure of road investments. Total employment to growth and employment to growth in manufacturing and service sectors are used as a measure of economic development. In order to achieve the above objective, the Granger Causality test at different level of aggregation is used to examine this relationship. First, the state as a single aggregate unit is used to examine the effect of the various road investments on the three employment to growth sectors. Second, different spatial groupings, such as Portland Metropolitan Counties vs. the rest of the state Counties, Urban Counties, vs. Rural Counties, Interstate Counties vs. Non-Interstate Counties, Coastal Counties vs. Non-Coastal Counties, and the Department of Transportation's five designated regions are used to examine this relationship. Finally, the county level as a single disaggregate unit is also used. The results highlighted the complexity of the relationship between road investments and economic development. The nature of this relationship varies from one region to another, and mainly depends on the level of aggregation in determining the direction of this relationship. At the aggregate level, the state as one geographic unit, the various road investments have a positive impact on the employment to growth in this region. In particular, total road expenditure and capital expenditure on primary and secondary roads have a one-way directional relationship runs from the various road expenditures to employment to growth, and the effect of this investment is long-term. This analysis also indicates that the different spatial groupings have demonstrated different relationships. Nevertheless, the general pattern for most spatial groupings tends to suggest either a one-way directional relationship runs from the various road expenditures to employment to growth or a bi-directional relationship. No findings support the hypothesis that employment to growth in the three economic sectors causes road expenditures, with the exception of very few cases, especially at the lower end of the analysis at the county level, where the results are highly discrepant and mixed. In addition, this research indicates that the time-lag effect measured by lag-length and accumulative lag effect changes as the level of aggregation changes. However, the general pattern seems to indicate that total road expenditures and capital expenditures for the three types of roads, particularly primary and secondary roads, have a long-term effect on employment to growth. Also, the relative magnitude effect of total road expenditures and capital expenditures on primary and secondary roads is greater on the employment to growth than is the comparable effect of maintenance expenditures in most spatial groupings. Furthermore, the effect of the various road expenditures on the type of employment (manufacturing and service) depends greatly on the level of aggregation and the type of road Investment Finally, this study provides public policy makers, transportation planners, and regional economic developers a better understanding of the complex relationship between road investment and economic development. A better understanding of this highly complex and dynamic relationship can guide decision makers to best utilize their limited resources. In addition, this research offers insight into the theories and works in the field of transportation and economic development. Title: The Effect of Road Investment on Economic Development: A Case Study of the Oregon Counties Author: Al-Alwan, Ameer Mohammed Year: 1991 Despite its significance and frequent mentioning in the literature, the relationship between road investment and economic development has never been clearly understood. A significant number of scholars in this field have always emphasized the need for further research to examine this complex and dynamic relationship. Historically, investment in transportation networks has played a great role in the development of cities, regions, and nations. This positive view is attributed to the indispensable role that water transportation, and then rail transport, played in the early development of Europe and the United States. In recent years, many scholars, as well as policy makers, have disputed that investment in transportation, and in particular roads, in the regions of a highly developed country like the United States will have a great impact on economic development. This disagreement and speculation about the role of transportation investment, especially roads which constitute a large portion of the transportation network, on economic development has made justification for roads funding difficult. This is coupled with the recent decline in federal funding for many civilian programs, and in particular, regional economic development program, that include investment in road systems. Furthermore, rising construction and maintenance costs for major highway systems have substantially out-paced the current funding levels. As a result of the shortage of roads funding and the lack of federal support, individual states have started to take on more responsibility for keeping their road network intact. In almost all the states in the nation, and Oregon is no exception, the state Departments of Transportation have started to use economic development as a criterion for roads funding. Therefore, it is the objective of this dissertation to examine the longitudinal impact of the various types of roads investments on economic development in Oregon in order to better understand this dynamic relationship. Total road expenditures, capital expenditures in the three types of roads (primary, secondary, and local), total maintenance expenditures, and maintenance expenditures in the three types of roads are used as a measure of road investments. Total employment to growth and employment to growth in manufacturing and service sectors are used as a measure of economic development. In order to achieve the above objective, the Granger Causality test at different level of aggregation is used to examine this relationship. First, the state as a single aggregate unit is used to examine the effect of the various road investments on the three employment to growth sectors. Second, different spatial groupings, such as Portland Metropolitan Counties vs. the rest of the state Counties, Urban Counties, vs. Rural Counties, Interstate Counties vs. Non-Interstate Counties, Coastal Counties vs. Non-Coastal Counties, and the Department of Transportation's five designated regions are used to examine this relationship. Finally, the county level as a single disaggregate unit is also used. The results highlighted the complexity of the relationship between road investments and economic development. The nature of this relationship varies from one region to another, and mainly depends on the level of aggregation in determining the direction of this relationship. At the aggregate level, the state as one geographic unit, the various road investments have a positive impact on the employment to growth in this region. In particular, total road expenditure and capital expenditure on primary and secondary roads have a one-way directional relationship runs from the various road expenditures to employment to growth, and the effect of this investment is long-term. This analysis also indicates that the different spatial groupings have demonstrated different relationships. Nevertheless, the general pattern for most spatial groupings tends to suggest either a one-way directional relationship runs from the various road expenditures to employment to growth or a bi-directional relationship. No findings support the hypothesis that employment to growth in the three economic sectors causes road expenditures, with the exception of very few cases, especially at the lower end of the analysis at the county level, where the results are highly discrepant and mixed. In addition, this research indicates that the time-lag effect measured by lag-length and accumulative lag effect changes as the level of aggregation changes. However, the general pattern seems to indicate that total road expenditures and capital expenditures for the three types of roads, particularly primary and secondary roads, have a long-term effect on employment to growth. Also, the relative magnitude effect of total road expenditures and capital expenditures on primary and secondary roads is greater on the employment to growth than is the comparable effect of maintenance expenditures in most spatial groupings. Furthermore, the effect of the various road expenditures on the type of employment (manufacturing and service) depends greatly on the level of aggregation and the type of road Investment Finally, this study provides public policy makers, transportation planners, and regional economic developers a better understanding of the complex relationship between road investment and economic development. A better understanding of this highly complex and dynamic relationship can guide decision makers to best utilize their limited resources. In addition, this research offers insight into the theories and works in the field of transportation and economic development. Close

• 2522. [Article] The role of herbivores and productivity on community structure of rocky shores of the Galapagos Islands, Ecuador

  Ecosystems are facing increasing threats from human related activities, such as overfishing, pollution, habitat destruction, species invasions, and diseases, among others. While oceanic islands provide ...

  Citation × Citation Citation Abstract Copy Title: The role of herbivores and productivity on community structure of rocky shores of the Galapagos Islands, Ecuador Author: Vinueza, Luis R. Ecosystems are facing increasing threats from human related activities, such as overfishing, pollution, habitat destruction, species invasions, and diseases, among others. While oceanic islands provide natural laboratories to understand ecological and evolutionary process, they are also particularly vulnerable to these impacts, given their usual isolation from the mainland and the typically high endemism of their flora and fauna. However, we still lack a general understanding of how marine systems in the Galapagos Islands will be affected by multiple human impacts, more severe environmental perturbations and warmer oceans. Rocky shores have been a prime example for the advancement of ecological theories and for the creation of important concepts to support management decisions and conservation actions, such as the predation hypothesis, the keystone species concept and the development of environmental stress models. However, the majority of this knowledge comes from studies conducted at higher latitudes. While most attention in the tropics has been focused on coral reefs and mangroves, other habitats such as rocky shores have remained largely unexplored. The upwelling ecosystems of the Galapagos Archipelago constitute an ideal model where likely consequences of interactions between global climate change and human impacts (e.g. exploitation) can be studied. In particular, variation in ocean upwelling and downwelling conditions (Palacios 2004) associated with seasonal and interannual variability and large scale oceanic-atmospheric perturbations such as ENSO cycles with its warm El Niño (~cessation of upwelling conditions) and cold La Niña (~abnormal upwelling) phase (Chavez et al. 1999). Thus, the Galapagos situation offers a scenario whereby I can assess the interaction among nutrient supply, herbivory and abiotic fluctuations. I used this dynamic system to evaluate the influence of bottom up and top down effects on rocky shore communities. In Chapter 2 I evaluated the role of consumers at different levels of productivity. I manipulated four levels of herbivory, from no macro-herbivores to all herbivores present, combinations of all together, mostly fish, crabs, crabs and including marine iguanas, crabs, sea turtles and fish. I demonstrated that at sites of low productivity herbivores had consistent effects on community structure by reducing the abundance of erect macroalgae which decreased macroalgal and sessile invertebrate's species richness, diversity and evenness. In areas of mid and high productivity the role of consumers was affected by seasonal effects and by warm and cold phases of El Niño Southern Oscillation. In Chapter 3 I evaluated the interactive effect of consumers on species richness, diversity and evenness of primary producers and discussed the results in the context of prevailing top down views on the regulation of marine tropical communities. I further discuss the importance to manage both top down and bottom up factors to maintain ecosystem structure and function at tropical locations. In chapter 4 I used resource and consumer-stress models to predict the outcome of plant animal interactions. I observed how the impact of herbivory on primary producers was exacerbated by thermal stress and reduced algal biomass at times of low productivity and high temperature; this pattern shifted as productivity increased and thermal stress relaxed, which led to herbivores increasing, not decreasing algal biomass. Finally, chapter 5 provides the main conclusions about our work. I put our work in context of past and present ecological theories. I also offer a framework to manage this system, oriented to increasing the resistance and resilience of this fragile ecosystem. Title: The role of herbivores and productivity on community structure of rocky shores of the Galapagos Islands, Ecuador Author: Vinueza, Luis R. Ecosystems are facing increasing threats from human related activities, such as overfishing, pollution, habitat destruction, species invasions, and diseases, among others. While oceanic islands provide natural laboratories to understand ecological and evolutionary process, they are also particularly vulnerable to these impacts, given their usual isolation from the mainland and the typically high endemism of their flora and fauna. However, we still lack a general understanding of how marine systems in the Galapagos Islands will be affected by multiple human impacts, more severe environmental perturbations and warmer oceans. Rocky shores have been a prime example for the advancement of ecological theories and for the creation of important concepts to support management decisions and conservation actions, such as the predation hypothesis, the keystone species concept and the development of environmental stress models. However, the majority of this knowledge comes from studies conducted at higher latitudes. While most attention in the tropics has been focused on coral reefs and mangroves, other habitats such as rocky shores have remained largely unexplored. The upwelling ecosystems of the Galapagos Archipelago constitute an ideal model where likely consequences of interactions between global climate change and human impacts (e.g. exploitation) can be studied. In particular, variation in ocean upwelling and downwelling conditions (Palacios 2004) associated with seasonal and interannual variability and large scale oceanic-atmospheric perturbations such as ENSO cycles with its warm El Niño (~cessation of upwelling conditions) and cold La Niña (~abnormal upwelling) phase (Chavez et al. 1999). Thus, the Galapagos situation offers a scenario whereby I can assess the interaction among nutrient supply, herbivory and abiotic fluctuations. I used this dynamic system to evaluate the influence of bottom up and top down effects on rocky shore communities. In Chapter 2 I evaluated the role of consumers at different levels of productivity. I manipulated four levels of herbivory, from no macro-herbivores to all herbivores present, combinations of all together, mostly fish, crabs, crabs and including marine iguanas, crabs, sea turtles and fish. I demonstrated that at sites of low productivity herbivores had consistent effects on community structure by reducing the abundance of erect macroalgae which decreased macroalgal and sessile invertebrate's species richness, diversity and evenness. In areas of mid and high productivity the role of consumers was affected by seasonal effects and by warm and cold phases of El Niño Southern Oscillation. In Chapter 3 I evaluated the interactive effect of consumers on species richness, diversity and evenness of primary producers and discussed the results in the context of prevailing top down views on the regulation of marine tropical communities. I further discuss the importance to manage both top down and bottom up factors to maintain ecosystem structure and function at tropical locations. In chapter 4 I used resource and consumer-stress models to predict the outcome of plant animal interactions. I observed how the impact of herbivory on primary producers was exacerbated by thermal stress and reduced algal biomass at times of low productivity and high temperature; this pattern shifted as productivity increased and thermal stress relaxed, which led to herbivores increasing, not decreasing algal biomass. Finally, chapter 5 provides the main conclusions about our work. I put our work in context of past and present ecological theories. I also offer a framework to manage this system, oriented to increasing the resistance and resilience of this fragile ecosystem. Close

• 2523. [Article] Overstory composition and stand structure shifts within inter-mixed ponderosa pine and lodgepole pine stands of the south-central Oregon pumice zone

  Ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta var. murrayana) forests of south-central Oregon have been extensively researched over the last century. However, little information has ...

  Citation × Citation Citation Abstract Copy Title: Overstory composition and stand structure shifts within inter-mixed ponderosa pine and lodgepole pine stands of the south-central Oregon pumice zone Author: Shuffield, Chaylon D. Ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta var. murrayana) forests of south-central Oregon have been extensively researched over the last century. However, little information has been reported on overstory composition and stand structure shifts associated with fire exclusion within inter-mixed ponderosa pine and lodgepole pine stands of the south-central Oregon pumice zone. In recent time, the lack of disturbance history and quantitative information needed to reconstruct historic stand conditions has become a growing concern for many ecologists. The need to collect quantitative information from remnant old-growth stands is imperative to improve restoration activities, incorporate stand-level diversity, identify the degree of successional departure, and to ensure valuable data is archived for future reference and ecological analysis. In Chapter 1, an exhaustive search for published information on early land-use practices specific to our study area was performed to: (1) identify the degree of Native American influence on vegetation; (2) identify direct and indirect Euro-American disturbances involving the loss of natural processes; and (3) establish a reference period for appropriate representation of historic conditions. In Chapter 2, remnant old-growth stands were analyzed using dendrochronological techniques and statistical comparisons to quantify: (1) shifts in overstory composition and stand structure; (2) growth and development of ponderosa pine and lodgepole pine across time; and to (3) characterize the influence of climate and fire on species recruitment. Our analysis indicated successional trajectory shifts occurred shortly after the loss of Native American influence beginning around 1850 and associated affects of intensive grazing following 1880. Age reconstruction displayed an exponential pattern of recruitment between 1880 and 1950. Since 1850, our analysis revealed a reduction in average tree basal area growth and height development of understory ponderosa pine and lodgepole pine. Ponderosa pine greater than 150 years old accounted for less than 5.0% of the total contemporary density, but composed 45.0% of the total basal area. Lodgepole pine greater than 100 years old accounted for approximately 3.0% of the total contemporary density and composed 12.8% of the total basal area. Stand density for our study area averaged 25.3 trees per hectare for ponderosa pine greater than 53.3 centimeters diameter at 1.4 meters. We report low levels of lodgepole pine recruitment (2/hectare/decade) prior to 1880 and suggest the long-term development of less fire-resistant lodgepole pine has been favored since fire exclusion. Furthermore, contemporary settings support conditions associated to atypical mountain pine beetle outbreaks and fire behavior known to cause mortality of large diameter ponderosa pine. Restoration of remnant inter-mixed stands requires the aggressive removal of lodgepole pine and re-introduction of fire to provide long-term sustainability of ecosystem health and preservation of large diameter ponderosa pine. Title: Overstory composition and stand structure shifts within inter-mixed ponderosa pine and lodgepole pine stands of the south-central Oregon pumice zone Author: Shuffield, Chaylon D. Ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta var. murrayana) forests of south-central Oregon have been extensively researched over the last century. However, little information has been reported on overstory composition and stand structure shifts associated with fire exclusion within inter-mixed ponderosa pine and lodgepole pine stands of the south-central Oregon pumice zone. In recent time, the lack of disturbance history and quantitative information needed to reconstruct historic stand conditions has become a growing concern for many ecologists. The need to collect quantitative information from remnant old-growth stands is imperative to improve restoration activities, incorporate stand-level diversity, identify the degree of successional departure, and to ensure valuable data is archived for future reference and ecological analysis. In Chapter 1, an exhaustive search for published information on early land-use practices specific to our study area was performed to: (1) identify the degree of Native American influence on vegetation; (2) identify direct and indirect Euro-American disturbances involving the loss of natural processes; and (3) establish a reference period for appropriate representation of historic conditions. In Chapter 2, remnant old-growth stands were analyzed using dendrochronological techniques and statistical comparisons to quantify: (1) shifts in overstory composition and stand structure; (2) growth and development of ponderosa pine and lodgepole pine across time; and to (3) characterize the influence of climate and fire on species recruitment. Our analysis indicated successional trajectory shifts occurred shortly after the loss of Native American influence beginning around 1850 and associated affects of intensive grazing following 1880. Age reconstruction displayed an exponential pattern of recruitment between 1880 and 1950. Since 1850, our analysis revealed a reduction in average tree basal area growth and height development of understory ponderosa pine and lodgepole pine. Ponderosa pine greater than 150 years old accounted for less than 5.0% of the total contemporary density, but composed 45.0% of the total basal area. Lodgepole pine greater than 100 years old accounted for approximately 3.0% of the total contemporary density and composed 12.8% of the total basal area. Stand density for our study area averaged 25.3 trees per hectare for ponderosa pine greater than 53.3 centimeters diameter at 1.4 meters. We report low levels of lodgepole pine recruitment (2/hectare/decade) prior to 1880 and suggest the long-term development of less fire-resistant lodgepole pine has been favored since fire exclusion. Furthermore, contemporary settings support conditions associated to atypical mountain pine beetle outbreaks and fire behavior known to cause mortality of large diameter ponderosa pine. Restoration of remnant inter-mixed stands requires the aggressive removal of lodgepole pine and re-introduction of fire to provide long-term sustainability of ecosystem health and preservation of large diameter ponderosa pine. Close

• 2524. [Article] Nutrient Profile and Nursery Feeding Damage of Halyomorpha halys (Hempitera: Pentatomidae)

  Halyomorpha halys Stål, brown marmorated stink bug or BMSB, is now present in 43 US states. A native of eastern Asia, this pest can feed on ~200 different plant species damaging bark, leaves, buds, stems, ...

  Citation × Citation Citation Abstract Copy Title: Nutrient Profile and Nursery Feeding Damage of Halyomorpha halys (Hempitera: Pentatomidae) Author: Skillman, Victoria P. Halyomorpha halys Stål, brown marmorated stink bug or BMSB, is now present in 43 US states. A native of eastern Asia, this pest can feed on ~200 different plant species damaging bark, leaves, buds, stems, and fruits. Many of these plant species include wild plants, ornamentals, and agricultural crops. BMSB has become a major pest for growers in different cropping systems from orchard to row crops. They are also a major nuisance for homeowners because they overwinter in high numbers in human structures, where they annoy occupants and can cause other problems. Currently, much research has focused on the control and biology of BMSB. This thesis focuses on areas of BMSB biology where there are substantial knowledge gaps: the nutritional ecology of wild BMSB, nutrient content of BMSB eggs, and how BMSB feeding affects nursery crop growth. Understanding of the nutritional profile of wild BMSB over the season can help us understand how BMSB behavior is driven by nutritional needs and can indicate periods when pest is nutrient-limited and potentially more susceptible to management. In Chapter 2, lipid, glycogen and sugar levels of wild adult BMSB populations were measured in the Willamette Valley of Oregon as they emerged from overwintering boxes from March through June and throughout the summer season from May to September. Emerging adults had lower nutrient levels than overwintering adults that remained in the shelter suggesting that nutrient limitation may drive adults to leave overwintering sites. Also, nutrient levels of emerging adults steadily declined over the months that they emerged. In the summer, nutrient levels of adults collected from holly host plants fluctuated, and a dip in nutrient levels was observed as the new generation of adults became abundant. In Chapter 3, the nutrient content of BMSB eggs were measured to describe what resources are provided to the progeny and to the natural enemies that feed on or develop within eggs. Also, various fresh and frozen egg masses are used for biological control studies, and nutrient comparisons were made between various egg masses to assess quality. BMSB eggs followed adult nutrient trends by having higher lipid levels compared to sugar and glycogen. Eggs did not vary in nutrient levels over the lifespan of the female suggesting that when supplied a consistent diet, females allocate a consistent amount of nutrient to their eggs as they age. Wild and colony egg clusters varied in lipid and sugar levels. The color change and age of the egg clusters did not influence the nutrient levels. The deployment length caused eggs to decrease in sugar and glycogen levels, however, temperature and deployment*temperature combinations did not. Eggs that were frozen at -80°C for 1-2 years were associated with declining lipid levels and increasing sugar levels. While BMSB has been reported to damage nursery crops, and especially fruit, their impact on plant growth has not been quantified. Experiments represented in Chapter 4 evaluated BMSB feeding damage to nursery plants by caging adults on established stock block trees in the field and young potted seedlings in the greenhouse. The impact appeared limited; the established trees and young seedlings mostly grew at similar rates to control plants. In addition to these three topics, four additional nutrient profiles studies and two studies on biological control are included in the Appendices. Baseline information on the nutrient levels of the general adult population of BMSB in Oregon (A.1), BMSB nymphs (A.3), and native stink bugs of Oregon (A.4) are provided. Nutrient comparisons in May-June revealed that BMSB collected from the host plant of holly had substantially higher nutrient reserves than BMSB just exiting overwintering (A.2). Methyl salicylate lures were tested in a nursery and found to have no significant effect on egg predation or parasitism (A.5). A commercially available entomopathogenic fungus was sprayed directly on BMSB nymphs; it induced 26% greater mortality than the controls over a 12-day period. Title: Nutrient Profile and Nursery Feeding Damage of Halyomorpha halys (Hempitera: Pentatomidae) Author: Skillman, Victoria P. Halyomorpha halys Stål, brown marmorated stink bug or BMSB, is now present in 43 US states. A native of eastern Asia, this pest can feed on ~200 different plant species damaging bark, leaves, buds, stems, and fruits. Many of these plant species include wild plants, ornamentals, and agricultural crops. BMSB has become a major pest for growers in different cropping systems from orchard to row crops. They are also a major nuisance for homeowners because they overwinter in high numbers in human structures, where they annoy occupants and can cause other problems. Currently, much research has focused on the control and biology of BMSB. This thesis focuses on areas of BMSB biology where there are substantial knowledge gaps: the nutritional ecology of wild BMSB, nutrient content of BMSB eggs, and how BMSB feeding affects nursery crop growth. Understanding of the nutritional profile of wild BMSB over the season can help us understand how BMSB behavior is driven by nutritional needs and can indicate periods when pest is nutrient-limited and potentially more susceptible to management. In Chapter 2, lipid, glycogen and sugar levels of wild adult BMSB populations were measured in the Willamette Valley of Oregon as they emerged from overwintering boxes from March through June and throughout the summer season from May to September. Emerging adults had lower nutrient levels than overwintering adults that remained in the shelter suggesting that nutrient limitation may drive adults to leave overwintering sites. Also, nutrient levels of emerging adults steadily declined over the months that they emerged. In the summer, nutrient levels of adults collected from holly host plants fluctuated, and a dip in nutrient levels was observed as the new generation of adults became abundant. In Chapter 3, the nutrient content of BMSB eggs were measured to describe what resources are provided to the progeny and to the natural enemies that feed on or develop within eggs. Also, various fresh and frozen egg masses are used for biological control studies, and nutrient comparisons were made between various egg masses to assess quality. BMSB eggs followed adult nutrient trends by having higher lipid levels compared to sugar and glycogen. Eggs did not vary in nutrient levels over the lifespan of the female suggesting that when supplied a consistent diet, females allocate a consistent amount of nutrient to their eggs as they age. Wild and colony egg clusters varied in lipid and sugar levels. The color change and age of the egg clusters did not influence the nutrient levels. The deployment length caused eggs to decrease in sugar and glycogen levels, however, temperature and deployment*temperature combinations did not. Eggs that were frozen at -80°C for 1-2 years were associated with declining lipid levels and increasing sugar levels. While BMSB has been reported to damage nursery crops, and especially fruit, their impact on plant growth has not been quantified. Experiments represented in Chapter 4 evaluated BMSB feeding damage to nursery plants by caging adults on established stock block trees in the field and young potted seedlings in the greenhouse. The impact appeared limited; the established trees and young seedlings mostly grew at similar rates to control plants. In addition to these three topics, four additional nutrient profiles studies and two studies on biological control are included in the Appendices. Baseline information on the nutrient levels of the general adult population of BMSB in Oregon (A.1), BMSB nymphs (A.3), and native stink bugs of Oregon (A.4) are provided. Nutrient comparisons in May-June revealed that BMSB collected from the host plant of holly had substantially higher nutrient reserves than BMSB just exiting overwintering (A.2). Methyl salicylate lures were tested in a nursery and found to have no significant effect on egg predation or parasitism (A.5). A commercially available entomopathogenic fungus was sprayed directly on BMSB nymphs; it induced 26% greater mortality than the controls over a 12-day period. Close

• 2525. [Article] Vegetation response following thinning in young Douglas-fir forests of western Oregon : can thinning accelerate development of late-successional structure and composition?

  Across western Oregon, Washington, and British Columbia, forest management practices over the past century reduced the amount of late-successional forest while simultaneously increasing the amount of young ...

  Citation × Citation Citation Abstract Copy Title: Vegetation response following thinning in young Douglas-fir forests of western Oregon : can thinning accelerate development of late-successional structure and composition? Author: Beggs, Liane R. Across western Oregon, Washington, and British Columbia, forest management practices over the past century reduced the amount of late-successional forest while simultaneously increasing the amount of young (less than 80 years old), managed Douglas-fir (Pseudotsuga menziesii) dominated forests. Recently, concerns over loss of late-successional habitat pushed management objectives on public lands away from timber production and toward maintenance and restoration of late-successional habitat. In accordance with these new objectives, The Young Stand Thinning and Diversity Study (YSTDS) was developed to test if thinning could accelerate development of latesuccessional habitat in young managed Douglas-fir forests. Though the YSTDS examines several components of forest ecosystems, the goal of this study was to investigate short-term (5-7 years post-treatment) responses of vegetation to thinning treatments and to evaluate this response in relation to long-term objectives of late-successional development. The study is located on the western slope of the central Oregon Cascades. It consists of four replications of four thinning treatments (treatment areas average 30 ha each) in 30-50 year old second-growth Douglas-fir forest stands. Treatments include a control, heavy thin, light thin, and light thin with gaps. Unlike traditional thinning, the thinning treatments in this study sought to maintain and enhance overstory structural diversity by: (1) retaining species other than Douglas-fir, (2) simulating low densities that characterized development of some old-growth stands, and (3) adding canopy gaps to enhance spatial diversity. Following treatment completion, first, third, and fifth-year vegetation responses were measured Results for overstory vegetation indicate that heavy thinning may accelerate development of large trees, one important component of old-growth structure. This was evident by faster growth of the largest trees in the heavy thin than in the control. A heavy thin may also permit more time for understory development than a lighter thin because canopies of heavy thinned stands remained open longer than canopies of light thinned stands. Variation in overstory cover, which may promote heterogeneous understory development, was higher in the treatment that included canopy gaps than in other treatments including the control. Although accelerated development of a multi-layered canopy was not evident in any treatment, retention of non-dominant tree species prevented simplification of vertical canopy structure by retaining layers that are typically removed by a low thinning prescription. In addition, mortality of non-dominant species was not greater in thinned treatments than in the control. In the understory, results suggest that thinning can increase abundance of some vegetative layers without encouraging homogenization of the understory by clonal shrubs or exotic species. The thinnings resulted in initial declines of bryophytes, tall shrubs, and low shrubs followed by subsequent recovery and growth. While herbs displayed little initial response, a release of early-seral species was evident by 5-7 years post-treatment. Initial changes following thinning were likely due to harvesting damage and/or alteration of microclimate while subsequent changes were probably also related to increased resource availability. It is expected that eventually similarities and differences in overstory structure among thinned treatments will be reflected in the understory. For example, variation in canopy cover created by the addition of canopy gaps was already reflected in the understory, as plant assemblages differed across the gradient from gaps to the thinned forest matrix. Hence, although understory vegetation was similar among heavy and light thins in the short-term, early closure of the canopy following a light thin could preclude continuation of late-seral understory development. Finally, the effect of canopy gaps on the understory was more apparent at a within-stand scale than at a stand scale. Had the within-stand scale been ignored, relevant information regarding understory response would have been overlooked. This indicates that spatial scale should be considered when assessing ecological patterns. In conclusion, it is acknowledged that there are drawbacks to thinning (e.g., certain species decline following thinning) It is also acknowledged that the short-term nature of the data permits only speculation regarding long-term succession. While these limitations are recognized, current trends indicate that a moderate to heavy thinning in combination with gap formation can hasten development of late-successional features in thinned stands relative to unthinned stands. Thus, thinning similar to that used in this study can be one useful tool in the management of young Douglas-fir forests. Title: Vegetation response following thinning in young Douglas-fir forests of western Oregon : can thinning accelerate development of late-successional structure and composition? Author: Beggs, Liane R. Across western Oregon, Washington, and British Columbia, forest management practices over the past century reduced the amount of late-successional forest while simultaneously increasing the amount of young (less than 80 years old), managed Douglas-fir (Pseudotsuga menziesii) dominated forests. Recently, concerns over loss of late-successional habitat pushed management objectives on public lands away from timber production and toward maintenance and restoration of late-successional habitat. In accordance with these new objectives, The Young Stand Thinning and Diversity Study (YSTDS) was developed to test if thinning could accelerate development of latesuccessional habitat in young managed Douglas-fir forests. Though the YSTDS examines several components of forest ecosystems, the goal of this study was to investigate short-term (5-7 years post-treatment) responses of vegetation to thinning treatments and to evaluate this response in relation to long-term objectives of late-successional development. The study is located on the western slope of the central Oregon Cascades. It consists of four replications of four thinning treatments (treatment areas average 30 ha each) in 30-50 year old second-growth Douglas-fir forest stands. Treatments include a control, heavy thin, light thin, and light thin with gaps. Unlike traditional thinning, the thinning treatments in this study sought to maintain and enhance overstory structural diversity by: (1) retaining species other than Douglas-fir, (2) simulating low densities that characterized development of some old-growth stands, and (3) adding canopy gaps to enhance spatial diversity. Following treatment completion, first, third, and fifth-year vegetation responses were measured Results for overstory vegetation indicate that heavy thinning may accelerate development of large trees, one important component of old-growth structure. This was evident by faster growth of the largest trees in the heavy thin than in the control. A heavy thin may also permit more time for understory development than a lighter thin because canopies of heavy thinned stands remained open longer than canopies of light thinned stands. Variation in overstory cover, which may promote heterogeneous understory development, was higher in the treatment that included canopy gaps than in other treatments including the control. Although accelerated development of a multi-layered canopy was not evident in any treatment, retention of non-dominant tree species prevented simplification of vertical canopy structure by retaining layers that are typically removed by a low thinning prescription. In addition, mortality of non-dominant species was not greater in thinned treatments than in the control. In the understory, results suggest that thinning can increase abundance of some vegetative layers without encouraging homogenization of the understory by clonal shrubs or exotic species. The thinnings resulted in initial declines of bryophytes, tall shrubs, and low shrubs followed by subsequent recovery and growth. While herbs displayed little initial response, a release of early-seral species was evident by 5-7 years post-treatment. Initial changes following thinning were likely due to harvesting damage and/or alteration of microclimate while subsequent changes were probably also related to increased resource availability. It is expected that eventually similarities and differences in overstory structure among thinned treatments will be reflected in the understory. For example, variation in canopy cover created by the addition of canopy gaps was already reflected in the understory, as plant assemblages differed across the gradient from gaps to the thinned forest matrix. Hence, although understory vegetation was similar among heavy and light thins in the short-term, early closure of the canopy following a light thin could preclude continuation of late-seral understory development. Finally, the effect of canopy gaps on the understory was more apparent at a within-stand scale than at a stand scale. Had the within-stand scale been ignored, relevant information regarding understory response would have been overlooked. This indicates that spatial scale should be considered when assessing ecological patterns. In conclusion, it is acknowledged that there are drawbacks to thinning (e.g., certain species decline following thinning) It is also acknowledged that the short-term nature of the data permits only speculation regarding long-term succession. While these limitations are recognized, current trends indicate that a moderate to heavy thinning in combination with gap formation can hasten development of late-successional features in thinned stands relative to unthinned stands. Thus, thinning similar to that used in this study can be one useful tool in the management of young Douglas-fir forests. Close

• 2526. [Article] Seasonal life history of Oncorhynchus mykiss in the South Fork John Day River Basin, Oregon

  Understanding seasonal changes in growth, survival, and movement rates is crucial to salmonid management. These life history characteristics provide a context for evaluation of management actions. We evaluated ...

  Citation × Citation Citation Abstract Copy Title: Seasonal life history of Oncorhynchus mykiss in the South Fork John Day River Basin, Oregon Author: Tattam, Ian A. Understanding seasonal changes in growth, survival, and movement rates is crucial to salmonid management. These life history characteristics provide a context for evaluation of management actions. We evaluated the life history of individually marked Oncorhynchus mykiss gairdneri in the South Fork John Day River basin in Northeastern Oregon. This thesis focuses on Murderers and Black Canyon creeks, two tributaries to the South Fork John Day. These are semi-arid, mid elevation basins with naturally reproducing populations of summer steelhead and redband trout (both O. mykiss). Summer steelhead populations in this basin have declined from historic abundances, and are protected under the Endangered Species Act. In Chapter 2, we evaluate life history variation in Murderers Creek during four consecutive seasons. Growth rate varied significantly with season (F[subscript 3,88] = 62.56, P < 0.0001), with most growth occurring during spring. Location and season interacted F[subscript 6,88] = 4.45, P < 0.001) to influence individual growth rates. As a result, regions of high growth potential shifted up and down-stream seasonally. However, we found low rates of O. mykiss movement (<3%) in Murderers Creek during summer, suggesting that individuals did not track resource availability at a large scale. Apparent survival rate varied among reaches, but was consistently higher in the upstream most reach compared to the two lowermost reaches. Survival rates were similar between summer and fall, indicating that declining fall temperatures did not increase mortality. A shift in population distribution occured during fall (September through December), as some O. mykiss emigrated from tributaries into the mainstem South Fork John Day River. In Chapter 3, we investigate differences in fall life history between and within tributaries. A significantly greater proportion of O. mykiss emigrated from Murderers Creek compared to Black Canyon Creek during two consecutive years (P < 0.001 for both years). There were no significant differences in proportion of emigrants between years within either stream (P > 0.10 for both streams). In Murderers Creek, odds of emigration were related to stream reach of summer residence. Odds of fall emigration were also significantly and positively related to body length in fall and growth rate during summer. This suggests that competitive dominants volitionally emigrated from Murderers Creek during fall. After emigration, O. mykiss dispersed primarily further downstream into the Mainstem John Day River. Radio-telemetry indicated that the majority of fall emigrants occupied a < 6 km section of the Mainstem John Day River. Fall emigrants had growth rates during their winter niche shift that were significantly (P < 0.001) higher than those of individuals remaining in tributaries. This study underscores the need to monitor during all seasons to accurately characterize habitat quality. Life history patterns are an important population response to environmental change. This thesis provides an ecological context for monitoring recovery of O. mykiss populations in the South Fork John Day River basin. Title: Seasonal life history of Oncorhynchus mykiss in the South Fork John Day River Basin, Oregon Author: Tattam, Ian A. Understanding seasonal changes in growth, survival, and movement rates is crucial to salmonid management. These life history characteristics provide a context for evaluation of management actions. We evaluated the life history of individually marked Oncorhynchus mykiss gairdneri in the South Fork John Day River basin in Northeastern Oregon. This thesis focuses on Murderers and Black Canyon creeks, two tributaries to the South Fork John Day. These are semi-arid, mid elevation basins with naturally reproducing populations of summer steelhead and redband trout (both O. mykiss). Summer steelhead populations in this basin have declined from historic abundances, and are protected under the Endangered Species Act. In Chapter 2, we evaluate life history variation in Murderers Creek during four consecutive seasons. Growth rate varied significantly with season (F[subscript 3,88] = 62.56, P < 0.0001), with most growth occurring during spring. Location and season interacted F[subscript 6,88] = 4.45, P < 0.001) to influence individual growth rates. As a result, regions of high growth potential shifted up and down-stream seasonally. However, we found low rates of O. mykiss movement (<3%) in Murderers Creek during summer, suggesting that individuals did not track resource availability at a large scale. Apparent survival rate varied among reaches, but was consistently higher in the upstream most reach compared to the two lowermost reaches. Survival rates were similar between summer and fall, indicating that declining fall temperatures did not increase mortality. A shift in population distribution occured during fall (September through December), as some O. mykiss emigrated from tributaries into the mainstem South Fork John Day River. In Chapter 3, we investigate differences in fall life history between and within tributaries. A significantly greater proportion of O. mykiss emigrated from Murderers Creek compared to Black Canyon Creek during two consecutive years (P < 0.001 for both years). There were no significant differences in proportion of emigrants between years within either stream (P > 0.10 for both streams). In Murderers Creek, odds of emigration were related to stream reach of summer residence. Odds of fall emigration were also significantly and positively related to body length in fall and growth rate during summer. This suggests that competitive dominants volitionally emigrated from Murderers Creek during fall. After emigration, O. mykiss dispersed primarily further downstream into the Mainstem John Day River. Radio-telemetry indicated that the majority of fall emigrants occupied a < 6 km section of the Mainstem John Day River. Fall emigrants had growth rates during their winter niche shift that were significantly (P < 0.001) higher than those of individuals remaining in tributaries. This study underscores the need to monitor during all seasons to accurately characterize habitat quality. Life history patterns are an important population response to environmental change. This thesis provides an ecological context for monitoring recovery of O. mykiss populations in the South Fork John Day River basin. Close

• 2527. [Article] White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon

  Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) ...

  Citation × Citation Citation Abstract Copy Title: White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon Author: Viste-Sparkman, Karen Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) are experiencing long-term population declines in the Willamette Valley of Oregon, where they are historically associated with oak woodlands. As secondary cavity-nesters, white-breasted nuthatches may be limited by the availability of existing cavities for nesting and roosting. Oak vegetation in the Willamette Valley has changed since European-American settlement times from vast areas of open oak savanna to isolated closed-canopy stands separated by agricultural fields. We examined nuthatch density, nest cavity selection, and nest success in relation to oak woodland structure and landscape context. We conducted point transect surveys in 3 strata: woodland interiors, large woodland edges, and small woodlands. We located and monitored nuthatch nests and sampled vegetation at nest locations and matching random locations around each nest. Woodland structure and edge density were measured at a 178-m radius (home range) scale, and landscape context was measured using vegetation cover within a 1-km radius around point transects and nests. We used program DISTANCE to fit detection functions and calculate nuthatch densities. We used conditional logistic regression to compare nest locations with random locations, and analyzed nest success with Mayfield logistic regression. White-breasted nuthatch density was significantly higher in small woodlands than in edges of large woodlands, which had higher nuthatch density than woodland interiors. Density of nuthatches increased with a combination of oak cover within a 1-km radius of the point, edge density within a 178-m radius, and number of oak trees >50 cm diameter at breast height (dbh) within a 100-m radius. Nest cavities were situated in oak trees containing more cavities than random oak trees that had cavities, and oak trees used as nest trees had a larger dbh than oak trees within random plots. Local woodland structure at nest locations was characterized by larger trees, measured by greater mean dbh, canopy cover, and basal area of oaks than random locations within the home range. Nest success in natural cavities was 71% and was not predicted by attributes of nest cavities, nest trees, local woodland structure at nests, woodland structure at the home range scale, or landscape context. These results suggest that the most suitable habitat for white-breasted nuthatches in the Willamette Valley includes oak woodlands in close proximity to one another with a high proportion of edge and mature oak trees. Managers should preserve trees containing cavities and large oak trees whenever possible. Thinning of small oaks and removal of conifers in oak woodlands to create more open, savanna-like conditions may also promote the development of larger oaks with more spreading branches, providing more opportunities for cavities to form and more foraging surface area for nuthatches. Title: White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon Author: Viste-Sparkman, Karen Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) are experiencing long-term population declines in the Willamette Valley of Oregon, where they are historically associated with oak woodlands. As secondary cavity-nesters, white-breasted nuthatches may be limited by the availability of existing cavities for nesting and roosting. Oak vegetation in the Willamette Valley has changed since European-American settlement times from vast areas of open oak savanna to isolated closed-canopy stands separated by agricultural fields. We examined nuthatch density, nest cavity selection, and nest success in relation to oak woodland structure and landscape context. We conducted point transect surveys in 3 strata: woodland interiors, large woodland edges, and small woodlands. We located and monitored nuthatch nests and sampled vegetation at nest locations and matching random locations around each nest. Woodland structure and edge density were measured at a 178-m radius (home range) scale, and landscape context was measured using vegetation cover within a 1-km radius around point transects and nests. We used program DISTANCE to fit detection functions and calculate nuthatch densities. We used conditional logistic regression to compare nest locations with random locations, and analyzed nest success with Mayfield logistic regression. White-breasted nuthatch density was significantly higher in small woodlands than in edges of large woodlands, which had higher nuthatch density than woodland interiors. Density of nuthatches increased with a combination of oak cover within a 1-km radius of the point, edge density within a 178-m radius, and number of oak trees >50 cm diameter at breast height (dbh) within a 100-m radius. Nest cavities were situated in oak trees containing more cavities than random oak trees that had cavities, and oak trees used as nest trees had a larger dbh than oak trees within random plots. Local woodland structure at nest locations was characterized by larger trees, measured by greater mean dbh, canopy cover, and basal area of oaks than random locations within the home range. Nest success in natural cavities was 71% and was not predicted by attributes of nest cavities, nest trees, local woodland structure at nests, woodland structure at the home range scale, or landscape context. These results suggest that the most suitable habitat for white-breasted nuthatches in the Willamette Valley includes oak woodlands in close proximity to one another with a high proportion of edge and mature oak trees. Managers should preserve trees containing cavities and large oak trees whenever possible. Thinning of small oaks and removal of conifers in oak woodlands to create more open, savanna-like conditions may also promote the development of larger oaks with more spreading branches, providing more opportunities for cavities to form and more foraging surface area for nuthatches. Close

• 2528. [Article] Foraging ecology and reproductive energetics of the Kittlitz's murrelet (Brachyramphus brevirostris) in Southeast Alaska

  The Kittlitz's murrelet (Brachyramphus brevirostris) is a species of conservation concern over the entirety of its known range, which spans coastal Alaska and northeastern Russia. Concerns about the status ...

  Citation × Citation Citation Abstract Copy Title: Foraging ecology and reproductive energetics of the Kittlitz's murrelet (Brachyramphus brevirostris) in Southeast Alaska Author: Hatch, Nick R. The Kittlitz's murrelet (Brachyramphus brevirostris) is a species of conservation concern over the entirety of its known range, which spans coastal Alaska and northeastern Russia. Concerns about the status of the species have been raised due to evidence of population declines in key breeding areas, low reproductive output, and perceived threats to adult survival. A general lack of information related to vital rates and natural history for this species has hampered efforts to address potential threats and drivers of population decline. This thesis addresses the hypothesis that foraging conditions and nutritional stress may be related to the observed low reproductive output and apparent population declines. I used stable isotope analysis of Kittlitz's murrelet feathers and blood to assess foraging habits during four separate periods across the annual cycle. I also used stable isotope signatures (δ¹⁵N and δ¹³C) in feathers from museum specimens collected in southeastern Alaska during 1907–1984 to investigate potential long-term trends in food habits and foraging ecology. I found that δ¹⁵N progressively increased by 5‰ between the vernal pre-alternate molt and the autumnal pre-basic molt, equivalent to an increase of 1.5 trophic levels for assimilated prey, whereas seasonal patterns in δ¹³C suggest shifts in foraging habitat between breeding and non-breeding periods. These results indicate that the pre-breeding diet was comprised primarily of low trophic level prey from offshore habitats, such as macrozooplankton and/or larval fish. During the summer breeding season, Kittlitz's murrelets gradually switched to consuming higher proportions of planktivorous fish from nearshore habitats. By the post-breeding period, during the pre-basic molt, the diet was comprised almost exclusively of higher trophic level prey, presumably forage fish, from offshore habitats. Based on stable isotope signatures of murrelet feathers from museum specimens, these seasonal patterns were evident during the past century (1907-2009). δ¹³C in feathers grown during pre- and post-breeding (pre-alternate and pre-basic molts, respectively) became significantly more depleted over the last century, however, suggesting either a gradual change in diet and/or foraging habitat or a long-term shift in the isotopic composition of prey. I investigated potential energy constraints on reproduction in Kittlitz's murrelets by constructing a bioenergetics model to estimate energy budgets for breeding adult Kittlitz's murrelets under different scenarios of prey energy content and commuting distance between foraging areas and nest sites. Estimated field metabolic rate (FMR) of breeding Kittlitz's murrelets during the chick-rearing period exceeded the hypothetical maximum sustainable working capacity (MSWC; 4 times basal metabolic rate [BMR]) under empirically derived scenarios of prey energy content and commuting distance. This suggests that, under conditions of low energy content in available prey and/or long commuting distances to inland nest sites, Kittlitz's murrelets would be required to expend energy at a rate that, if maintained over an extended period, could be detrimental to subsequent adult survival and overall fitness. In addition, energy expenditure rates at the high end of the estimated range may exceed the rate at which food energy can be assimilated by adult murrelets. Metabolism of fat reserves, as indicated by mass loss during the breeding season, may be a partial, although limited, solution to periods of high energy demand for breeding adults. This thesis research is the first to indicate that Kittlitz's murrelets rely on distinctly different prey resources during different periods of the annual cycle. The previously unappreciated seasonal complexity of Kittlitz's murrelet foraging ecology offers a new perspective on potential factors limiting survival and reproduction in this species of conservation concern. In addition, my research suggests an adaptive explanation for the low breeding frequency and low reproductive output of Kittlitz's murrelets that is related to the exceptionally high energy expenditure rates required to raise young at nest sites as much as 70 km inland from the coast and up to 2,500 m above sea level. Because of their high level of reproductive effort, Kittlitz's murrelets may be more dependent on the high availability of high-lipid marine prey than other seabirds. Title: Foraging ecology and reproductive energetics of the Kittlitz's murrelet (Brachyramphus brevirostris) in Southeast Alaska Author: Hatch, Nick R. The Kittlitz's murrelet (Brachyramphus brevirostris) is a species of conservation concern over the entirety of its known range, which spans coastal Alaska and northeastern Russia. Concerns about the status of the species have been raised due to evidence of population declines in key breeding areas, low reproductive output, and perceived threats to adult survival. A general lack of information related to vital rates and natural history for this species has hampered efforts to address potential threats and drivers of population decline. This thesis addresses the hypothesis that foraging conditions and nutritional stress may be related to the observed low reproductive output and apparent population declines. I used stable isotope analysis of Kittlitz's murrelet feathers and blood to assess foraging habits during four separate periods across the annual cycle. I also used stable isotope signatures (δ¹⁵N and δ¹³C) in feathers from museum specimens collected in southeastern Alaska during 1907–1984 to investigate potential long-term trends in food habits and foraging ecology. I found that δ¹⁵N progressively increased by 5‰ between the vernal pre-alternate molt and the autumnal pre-basic molt, equivalent to an increase of 1.5 trophic levels for assimilated prey, whereas seasonal patterns in δ¹³C suggest shifts in foraging habitat between breeding and non-breeding periods. These results indicate that the pre-breeding diet was comprised primarily of low trophic level prey from offshore habitats, such as macrozooplankton and/or larval fish. During the summer breeding season, Kittlitz's murrelets gradually switched to consuming higher proportions of planktivorous fish from nearshore habitats. By the post-breeding period, during the pre-basic molt, the diet was comprised almost exclusively of higher trophic level prey, presumably forage fish, from offshore habitats. Based on stable isotope signatures of murrelet feathers from museum specimens, these seasonal patterns were evident during the past century (1907-2009). δ¹³C in feathers grown during pre- and post-breeding (pre-alternate and pre-basic molts, respectively) became significantly more depleted over the last century, however, suggesting either a gradual change in diet and/or foraging habitat or a long-term shift in the isotopic composition of prey. I investigated potential energy constraints on reproduction in Kittlitz's murrelets by constructing a bioenergetics model to estimate energy budgets for breeding adult Kittlitz's murrelets under different scenarios of prey energy content and commuting distance between foraging areas and nest sites. Estimated field metabolic rate (FMR) of breeding Kittlitz's murrelets during the chick-rearing period exceeded the hypothetical maximum sustainable working capacity (MSWC; 4 times basal metabolic rate [BMR]) under empirically derived scenarios of prey energy content and commuting distance. This suggests that, under conditions of low energy content in available prey and/or long commuting distances to inland nest sites, Kittlitz's murrelets would be required to expend energy at a rate that, if maintained over an extended period, could be detrimental to subsequent adult survival and overall fitness. In addition, energy expenditure rates at the high end of the estimated range may exceed the rate at which food energy can be assimilated by adult murrelets. Metabolism of fat reserves, as indicated by mass loss during the breeding season, may be a partial, although limited, solution to periods of high energy demand for breeding adults. This thesis research is the first to indicate that Kittlitz's murrelets rely on distinctly different prey resources during different periods of the annual cycle. The previously unappreciated seasonal complexity of Kittlitz's murrelet foraging ecology offers a new perspective on potential factors limiting survival and reproduction in this species of conservation concern. In addition, my research suggests an adaptive explanation for the low breeding frequency and low reproductive output of Kittlitz's murrelets that is related to the exceptionally high energy expenditure rates required to raise young at nest sites as much as 70 km inland from the coast and up to 2,500 m above sea level. Because of their high level of reproductive effort, Kittlitz's murrelets may be more dependent on the high availability of high-lipid marine prey than other seabirds. Close

• 2529. [Article] A cooperative effort to track Humboldt squid invasions in Oregon

  Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing ...

  Citation × Citation Citation Abstract Copy Title: A cooperative effort to track Humboldt squid invasions in Oregon Author: Chesney, Tanya A. Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing their range expansion from Mexico is poorly understood due to the recent nature of their "invasion" and a lack of monitoring. Humboldt squid are large predators that have the potential to affect ecosystem structure and fisheries because of their high-energy demands and ability to exploit a variety of oceanographic conditions and prey sources. Developing baseline distribution information is a critical first step to assess their potential ecological, social, and economic impacts, and to develop models to predict future range expansion. This study has two main objectives: (1) to document where and when Humboldt squid have been present in Oregon through cooperative fisheries research, and (2) to correlate the sightings with oceanographic conditions using a geographic information system (GIS) and species distribution modeling (SDM). I conducted 54 interviews with local fishermen and aggregated their squid sightings with available fishery-independent survey and fishery-dependent observer data from the National Marine Fisheries Service. I compiled a total of 339 Humboldt squid sightings, reported for the years 2002-2011 from the Oregon coast to 131° west longitude. Correlation analyses were performed for Humboldt squid sightings and sea surface temperature (SST), chlorophyll a content (chla), sea surface height anomalies (SSH), dissolved oxygen at 30 m depth (30 m DO), and sea surface salinity (SSS) using a GIS, nonparametric multiplicative regression (NPMR) habitat modeling, and maximum entropy modeling (Maxent). Results indicate that oceanographic conditions have the potential to influence Humboldt squid occurrence, and in Oregon, sightings vary temporally and spatially. Combining the sightings from fishermen and scientific surveys greatly enhanced the spatial extent of the data. Humboldt squid were most frequently observed between 124.4°W and 125°W in proximity to the shelf-break at the 200 m isobath, with peak sightings (116) recorded in 2009 and the fewest (6) reported in 2003 and 2011. The highest occurrence of Humboldt squid were observed at a SST of 10.5-13.0°C, 0.26-3.0 mg m⁻³ chla content, -4.0-1.0 m SSH anomalies, 32.2-32.8 psu SSS, and at 3-4.5 ml L⁻¹ and 6-7 ml L⁻¹ 30 m depth DO. Maps of estimated likelihood of occurrence generated by NPMR were consistent with overlayed observations from fishermen, which were not used in the model because they were limited to presence-only information. An interdisciplinary approach that incorporates cooperative fisheries research and ecosystem-based management is necessary for monitoring Humboldt squid in Oregon. Traditional methods are insufficient because Humboldt squid are data-poor, highly migratory, and are main predators of many commercially important fisheries in Oregon. Based on my findings, sightings recorded by fishermen covered a much larger area over a longer time frame than the scientific survey and observer data, and excluding their knowledge would have led to a different interpretation of Humboldt squid distribution and environmental tolerances. Although there is uncertainty in the data from potential map bias or misidentification of smaller Humboldt squid, incorporating sightings from fishermen with traditional fisheries research increases the quantity and quality of information. Cooperative monitoring for Humboldt squid could include training in species identification and sea condition reporting in logbooks. Future "invasions" are likely, and more eyes on the water will improve our understanding of the behavior and impacts of Humboldt squid on coastal resources. Title: A cooperative effort to track Humboldt squid invasions in Oregon Author: Chesney, Tanya A. Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing their range expansion from Mexico is poorly understood due to the recent nature of their "invasion" and a lack of monitoring. Humboldt squid are large predators that have the potential to affect ecosystem structure and fisheries because of their high-energy demands and ability to exploit a variety of oceanographic conditions and prey sources. Developing baseline distribution information is a critical first step to assess their potential ecological, social, and economic impacts, and to develop models to predict future range expansion. This study has two main objectives: (1) to document where and when Humboldt squid have been present in Oregon through cooperative fisheries research, and (2) to correlate the sightings with oceanographic conditions using a geographic information system (GIS) and species distribution modeling (SDM). I conducted 54 interviews with local fishermen and aggregated their squid sightings with available fishery-independent survey and fishery-dependent observer data from the National Marine Fisheries Service. I compiled a total of 339 Humboldt squid sightings, reported for the years 2002-2011 from the Oregon coast to 131° west longitude. Correlation analyses were performed for Humboldt squid sightings and sea surface temperature (SST), chlorophyll a content (chla), sea surface height anomalies (SSH), dissolved oxygen at 30 m depth (30 m DO), and sea surface salinity (SSS) using a GIS, nonparametric multiplicative regression (NPMR) habitat modeling, and maximum entropy modeling (Maxent). Results indicate that oceanographic conditions have the potential to influence Humboldt squid occurrence, and in Oregon, sightings vary temporally and spatially. Combining the sightings from fishermen and scientific surveys greatly enhanced the spatial extent of the data. Humboldt squid were most frequently observed between 124.4°W and 125°W in proximity to the shelf-break at the 200 m isobath, with peak sightings (116) recorded in 2009 and the fewest (6) reported in 2003 and 2011. The highest occurrence of Humboldt squid were observed at a SST of 10.5-13.0°C, 0.26-3.0 mg m⁻³ chla content, -4.0-1.0 m SSH anomalies, 32.2-32.8 psu SSS, and at 3-4.5 ml L⁻¹ and 6-7 ml L⁻¹ 30 m depth DO. Maps of estimated likelihood of occurrence generated by NPMR were consistent with overlayed observations from fishermen, which were not used in the model because they were limited to presence-only information. An interdisciplinary approach that incorporates cooperative fisheries research and ecosystem-based management is necessary for monitoring Humboldt squid in Oregon. Traditional methods are insufficient because Humboldt squid are data-poor, highly migratory, and are main predators of many commercially important fisheries in Oregon. Based on my findings, sightings recorded by fishermen covered a much larger area over a longer time frame than the scientific survey and observer data, and excluding their knowledge would have led to a different interpretation of Humboldt squid distribution and environmental tolerances. Although there is uncertainty in the data from potential map bias or misidentification of smaller Humboldt squid, incorporating sightings from fishermen with traditional fisheries research increases the quantity and quality of information. Cooperative monitoring for Humboldt squid could include training in species identification and sea condition reporting in logbooks. Future "invasions" are likely, and more eyes on the water will improve our understanding of the behavior and impacts of Humboldt squid on coastal resources. Close

• 2530. [Article] Historical disturbance regimes as a reference for forest policy

  Using the historical range of forest conditions as a reference for managing landscapes has been proposed as a "coarse-filter" approach to biodiversity conservation. By emulating historical disturbance ...

  Citation × Citation Citation Abstract Copy Title: Historical disturbance regimes as a reference for forest policy Author: Thompson, Jonathan R. Using the historical range of forest conditions as a reference for managing landscapes has been proposed as a "coarse-filter" approach to biodiversity conservation. By emulating historical disturbance processes, it is thought that forest management can produce forest composition and structure similar to the conditions that once supported the native biota. Although several examples of disturbance-based management exist, only recently has this concept been incorporated into policy. This thesis explored hypotheses related to disturbance-based forest policy through a literature review, policy analyses, and simulation experiments. The primary objective of chapter 2 was to examine several examples disturbance-based forest management and evaluate their potential to transition into policy within North America. The review highlighted two Canadian provinces British Columbia and Ontario--that have codified disturbance-based management but used distinct methodologies. Nearly all of the forests in these provinces are government owned, which assisted policy development. In addition, both policy-structures focused on emulating stand-replacing fires that are characteristic in boreal forests; this minimized the costs and the degree of departure from conventional forest management. In much of the U.S., land tenure is complex and disturbance regimes vary widely; this presents difficult challenges for disturbance-based policy development. In the third chapter, disturbance-based policies were developed that attempted to address these challenges. Using datasets from the Coastal Landscape Analysis and Modeling Study (CLAMS) and the Landscape Management and Policy Simulation model (LAMPS), the economic costs and ecological benefits of several policy structures were explored. The policies included two variants of the current policy structure and three policies reflecting various aspects of the natural disturbance regime. The study area was the 3-million hectare Oregon Coast Range. Four owner groups were recognized--forest industry, nonindustrial private, state, and federal. The management intentions of each group guided the application of policies. Disturbance-based policies were primarily addressed to clearcutting on private lands because it constituted the preponderance of harvesting in the region. Information on the Coast Range's historical fire regime was used as a reference to develop disturbance-based policies. Fire severity was emulated with green-tree retention standards; fire frequency was emulated with annual harvestable area restrictions; and fire extent was emulated with harvest-unit size regulations. LAMPS projected landscape conditions, forest dynamics, management activities (clearcutting, thinning), and harvest volumes over the next century. Simulated disturbance-based policies produced age-class distributions more similar to the historical range than those created by the current policy structure. The proportions of early seral and young forest were within the historical range within 100 yrs; within this timeframe, older forests moved closer to but were still below historical conditions. In contrast, patch size distributions were less similar to historical conditions. This was because, even after a ten-fold increase in the average harvest size, the clearcut size limit remained well below the average historical fire size. Also, this was due to the scale of the analysis, which treated multiple proximate harvest-units as individual disturbance events. Therefore, regions with a high density of clearcuts, which were ubiquitous in the current policy scenarios, more closely resembled the large historical fire size. In the near term, annual revenue produced by the disturbance-based policies was estimated to be 20 to 60 percent lower than the current policy. However, relative costs were reduced significantly through time. This reflected the degree of departure between the modem and historical disturbance regimes. This simulation experiment suggested that policies attempting to reproduce historical conditions in the Coast Range would require federal forests to provide large patches of old forest that were conmon in the historical landscape. Employing public lands for this purpose would dampen costs to private landowners who would continue harvesting and provide young and early seral forest structure, which were also historically abundant. In addition, this experiment illustrated the difficultly of meeting regional-scale conservation goals across multiple private landowners and suggested that distributing costs and benefits equitably across large landscapes could be a significant challenge. Title: Historical disturbance regimes as a reference for forest policy Author: Thompson, Jonathan R. Using the historical range of forest conditions as a reference for managing landscapes has been proposed as a "coarse-filter" approach to biodiversity conservation. By emulating historical disturbance processes, it is thought that forest management can produce forest composition and structure similar to the conditions that once supported the native biota. Although several examples of disturbance-based management exist, only recently has this concept been incorporated into policy. This thesis explored hypotheses related to disturbance-based forest policy through a literature review, policy analyses, and simulation experiments. The primary objective of chapter 2 was to examine several examples disturbance-based forest management and evaluate their potential to transition into policy within North America. The review highlighted two Canadian provinces British Columbia and Ontario--that have codified disturbance-based management but used distinct methodologies. Nearly all of the forests in these provinces are government owned, which assisted policy development. In addition, both policy-structures focused on emulating stand-replacing fires that are characteristic in boreal forests; this minimized the costs and the degree of departure from conventional forest management. In much of the U.S., land tenure is complex and disturbance regimes vary widely; this presents difficult challenges for disturbance-based policy development. In the third chapter, disturbance-based policies were developed that attempted to address these challenges. Using datasets from the Coastal Landscape Analysis and Modeling Study (CLAMS) and the Landscape Management and Policy Simulation model (LAMPS), the economic costs and ecological benefits of several policy structures were explored. The policies included two variants of the current policy structure and three policies reflecting various aspects of the natural disturbance regime. The study area was the 3-million hectare Oregon Coast Range. Four owner groups were recognized--forest industry, nonindustrial private, state, and federal. The management intentions of each group guided the application of policies. Disturbance-based policies were primarily addressed to clearcutting on private lands because it constituted the preponderance of harvesting in the region. Information on the Coast Range's historical fire regime was used as a reference to develop disturbance-based policies. Fire severity was emulated with green-tree retention standards; fire frequency was emulated with annual harvestable area restrictions; and fire extent was emulated with harvest-unit size regulations. LAMPS projected landscape conditions, forest dynamics, management activities (clearcutting, thinning), and harvest volumes over the next century. Simulated disturbance-based policies produced age-class distributions more similar to the historical range than those created by the current policy structure. The proportions of early seral and young forest were within the historical range within 100 yrs; within this timeframe, older forests moved closer to but were still below historical conditions. In contrast, patch size distributions were less similar to historical conditions. This was because, even after a ten-fold increase in the average harvest size, the clearcut size limit remained well below the average historical fire size. Also, this was due to the scale of the analysis, which treated multiple proximate harvest-units as individual disturbance events. Therefore, regions with a high density of clearcuts, which were ubiquitous in the current policy scenarios, more closely resembled the large historical fire size. In the near term, annual revenue produced by the disturbance-based policies was estimated to be 20 to 60 percent lower than the current policy. However, relative costs were reduced significantly through time. This reflected the degree of departure between the modem and historical disturbance regimes. This simulation experiment suggested that policies attempting to reproduce historical conditions in the Coast Range would require federal forests to provide large patches of old forest that were conmon in the historical landscape. Employing public lands for this purpose would dampen costs to private landowners who would continue harvesting and provide young and early seral forest structure, which were also historically abundant. In addition, this experiment illustrated the difficultly of meeting regional-scale conservation goals across multiple private landowners and suggested that distributing costs and benefits equitably across large landscapes could be a significant challenge. Close