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• 811. [Article] Climate Change Impact Assessment for Surface Transportation in the Pacific Northwest and Alaska

  The states in the Pacific Northwest and Alaska region share interconnected transportation networks for people, goods, and services that support the regional economy, mobility, and human safety. Regional ...

  Citation × Citation Citation Abstract Copy Title: Climate Change Impact Assessment for Surface Transportation in the Pacific Northwest and Alaska Author: MacArthur, John, Mote, Philip, Figliozzi, Miguel A., Ideker, Jason, Lee, Ming Year: 2012 The states in the Pacific Northwest and Alaska region share interconnected transportation networks for people, goods, and services that support the regional economy, mobility, and human safety. Regional weather has and will continue to affect the physical condition and serviceability of these networks, yet the nature of climate changes and their potential impacts on the regional transportation system and its use are very poorly understood. The world’s leading climate scientists, such as the Intergovernmental Panel for Climate Change, have reached consensus that global climate changes are being observed and will continue into the future, particularly increasing temperatures. Given this fact, the widely diverse topography, climate regimes, and localized variability of impacts within the region complicate efforts to understand and plan for adapting to the potential impacts of climate change on the regional transportation system. The rising costs of building and maintaining reliable transportation infrastructure place tremendous pressure on transportation planners, engineers, researchers and policy makers to deliver resilient transportation systems and maximize return on investment. As such, there is an urgent need to synthesize information to characterize the regional impacts of climate change to support the development of economical and resilient adaptation strategies. Climate impacts are posing continued challenges for state departments of transportation (DOT). Changing weather patterns and their associated physical, financial, and social impacts are affecting or will affect the way transportation professionals finance, plan, design construct, operate, and maintain multimodal transportation infrastructure. Many state transportation agency procedures and practices were developed without full consideration of the likely impacts of climate change. For example, more frequent, high intensity precipitation events and associated floods may lead to expensive and unpredictable catastrophic failures of roads and bridges designed with outdated hydrologic data. DOTs could experience hundreds of millions of dollars in infrastructure damage that potentially could be avoided with more robust data collection, planning, and design tools/methods for managing risks. Likewise, climate-related socioeconomic changes may also be occurring, but transportation planners are currently ill-equipped to analyze them and may be delivering transportation projects that do not address future needs. Decisions made today on the planning and design of the regional transportation system will affect resiliency of the system as region tries to adapt to climate change. Making well informed and thoughtful decisions now will help avoid costly modifications and disruptions to operations in the future. This report is built on several significant reports and projects that have been recently published. In 2008, the Transportation Research Board released the Special Report 290: Potential Impacts of Climate Change on U.S. Transportation, which primarily focused on the consequences of climate change for U.S. transportation infrastructure and operations. The report also offers recommendations for both research and actions that can be taken to prepare for climate change. A similar study released by U.S. Department of Transportation, Impacts of Climate Change and Variability on Transportation Systems and Infrastructure: Gulf Coast Study, Phase I, explores the vulnerabilities of transportation systems in the Gulf Coast region to potential changes in weather patterns and related impacts, as well as the effect of natural land subsidence and other environmental factors in the region. The area examined by the study includes 48 contiguous counties in four states, running from Galveston, Texas, to Mobile, Alabama. In addition to these national reports, there are a variety studies that look at the scenarios of future climate for the Pacific Northwest. Most notably are the Climate Impacts Group’s Washington Climate Change Impacts Assessment and the Oregon Climate Change Research Institute’s Oregon Climate Assessment Report, which developed climate change scenarios for Oregon and Washington State. The objective of this research project was to conduct a preliminary vulnerability assessment of the risks and vulnerabilities climate change poses to the surface transportation infrastructure system in the Pacific Northwest and Alaska region. The report: synthesizes data to characterize the region’s climate, identifies potential impacts on the regional transportation system, identifies critical infrastructure vulnerable to climate change impacts, and provides recommendations for more detailed analysis and research needs as appropriate to support managing risks and opportunities to adapt multimodal surface transportation infrastructure to climate change impacts. Transportation professionals and policy makers can use the results of this report to build a breadth of knowledge and information on regional climate change impacts, understanding vulnerabilities of the transportation system and begin creating more quantitative risk assessment models. Title: Climate Change Impact Assessment for Surface Transportation in the Pacific Northwest and Alaska Author: MacArthur, John, Mote, Philip, Figliozzi, Miguel A., Ideker, Jason, Lee, Ming Year: 2012 The states in the Pacific Northwest and Alaska region share interconnected transportation networks for people, goods, and services that support the regional economy, mobility, and human safety. Regional weather has and will continue to affect the physical condition and serviceability of these networks, yet the nature of climate changes and their potential impacts on the regional transportation system and its use are very poorly understood. The world’s leading climate scientists, such as the Intergovernmental Panel for Climate Change, have reached consensus that global climate changes are being observed and will continue into the future, particularly increasing temperatures. Given this fact, the widely diverse topography, climate regimes, and localized variability of impacts within the region complicate efforts to understand and plan for adapting to the potential impacts of climate change on the regional transportation system. The rising costs of building and maintaining reliable transportation infrastructure place tremendous pressure on transportation planners, engineers, researchers and policy makers to deliver resilient transportation systems and maximize return on investment. As such, there is an urgent need to synthesize information to characterize the regional impacts of climate change to support the development of economical and resilient adaptation strategies. Climate impacts are posing continued challenges for state departments of transportation (DOT). Changing weather patterns and their associated physical, financial, and social impacts are affecting or will affect the way transportation professionals finance, plan, design construct, operate, and maintain multimodal transportation infrastructure. Many state transportation agency procedures and practices were developed without full consideration of the likely impacts of climate change. For example, more frequent, high intensity precipitation events and associated floods may lead to expensive and unpredictable catastrophic failures of roads and bridges designed with outdated hydrologic data. DOTs could experience hundreds of millions of dollars in infrastructure damage that potentially could be avoided with more robust data collection, planning, and design tools/methods for managing risks. Likewise, climate-related socioeconomic changes may also be occurring, but transportation planners are currently ill-equipped to analyze them and may be delivering transportation projects that do not address future needs. Decisions made today on the planning and design of the regional transportation system will affect resiliency of the system as region tries to adapt to climate change. Making well informed and thoughtful decisions now will help avoid costly modifications and disruptions to operations in the future. This report is built on several significant reports and projects that have been recently published. In 2008, the Transportation Research Board released the Special Report 290: Potential Impacts of Climate Change on U.S. Transportation, which primarily focused on the consequences of climate change for U.S. transportation infrastructure and operations. The report also offers recommendations for both research and actions that can be taken to prepare for climate change. A similar study released by U.S. Department of Transportation, Impacts of Climate Change and Variability on Transportation Systems and Infrastructure: Gulf Coast Study, Phase I, explores the vulnerabilities of transportation systems in the Gulf Coast region to potential changes in weather patterns and related impacts, as well as the effect of natural land subsidence and other environmental factors in the region. The area examined by the study includes 48 contiguous counties in four states, running from Galveston, Texas, to Mobile, Alabama. In addition to these national reports, there are a variety studies that look at the scenarios of future climate for the Pacific Northwest. Most notably are the Climate Impacts Group’s Washington Climate Change Impacts Assessment and the Oregon Climate Change Research Institute’s Oregon Climate Assessment Report, which developed climate change scenarios for Oregon and Washington State. The objective of this research project was to conduct a preliminary vulnerability assessment of the risks and vulnerabilities climate change poses to the surface transportation infrastructure system in the Pacific Northwest and Alaska region. The report: synthesizes data to characterize the region’s climate, identifies potential impacts on the regional transportation system, identifies critical infrastructure vulnerable to climate change impacts, and provides recommendations for more detailed analysis and research needs as appropriate to support managing risks and opportunities to adapt multimodal surface transportation infrastructure to climate change impacts. Transportation professionals and policy makers can use the results of this report to build a breadth of knowledge and information on regional climate change impacts, understanding vulnerabilities of the transportation system and begin creating more quantitative risk assessment models. Close

• 812. [Article] Overview of the mars pathfinder mission : launch through landing, surface operations, data sheets, and science results

  copyrighted by American Geophysical Union

  Citation × Citation Citation Abstract Copy Title: Overview of the mars pathfinder mission : launch through landing, surface operations, data sheets, and science results Author: Sullivan, R., Reider, R., Jaumann, R., Crisp, J. A., Golombek, M. P., Greely, R., Moore, H. J., Herkenhoff, K. E., Haldemann, A. F. C., Singer, R. B., Stoker, C. R., Thomas, N., Madsen, M. B., Bridges, N. T., Haberle, R. M., Keller, H. U., Cook, R. A., Murchie, S. L., Schofield, J. T., Manning, R. M., Maki, J. N., Kirk, R. L., Thurman, S. W., Malin, M. C., Hargraves, R. B., Barnes, Jeffrey R., Kallemeyn, P. H., Rivellini, T. P., Seiff, A., Wänke, H., Hviid, S. F., Parker, T. J., Magalhães, J. A., Folkner, W. M., Anderson, R. C., Johnson, J. R., Soderblom, L. A., Wilson, G. R., Matijevic, J., Harris, J. A., Tomasko, M. G., Murphy, J. R., Brückner, J., Bell III, J. R., Knudsen, J. M., Smith, P. H., Britt, D. T., Spencer, D. A., Vaughn, R. M., Larsen, S., Economou, T., Lemmon, M. T., McSween, H. Y. copyrighted by American Geophysical Union Title: Overview of the mars pathfinder mission : launch through landing, surface operations, data sheets, and science results Author: Sullivan, R., Reider, R., Jaumann, R., Crisp, J. A., Golombek, M. P., Greely, R., Moore, H. J., Herkenhoff, K. E., Haldemann, A. F. C., Singer, R. B., Stoker, C. R., Thomas, N., Madsen, M. B., Bridges, N. T., Haberle, R. M., Keller, H. U., Cook, R. A., Murchie, S. L., Schofield, J. T., Manning, R. M., Maki, J. N., Kirk, R. L., Thurman, S. W., Malin, M. C., Hargraves, R. B., Barnes, Jeffrey R., Kallemeyn, P. H., Rivellini, T. P., Seiff, A., Wänke, H., Hviid, S. F., Parker, T. J., Magalhães, J. A., Folkner, W. M., Anderson, R. C., Johnson, J. R., Soderblom, L. A., Wilson, G. R., Matijevic, J., Harris, J. A., Tomasko, M. G., Murphy, J. R., Brückner, J., Bell III, J. R., Knudsen, J. M., Smith, P. H., Britt, D. T., Spencer, D. A., Vaughn, R. M., Larsen, S., Economou, T., Lemmon, M. T., McSween, H. Y. copyrighted by American Geophysical Union Close

• 813. [Article] Juvenile coho salmon movement and migration through tide gates

  Tidal marshlands in the upper estuary ecotone provide essential habitat for juvenile salmonids. In this environment, salmonids grow rapidly and acclimate to saltwater. Worldwide, tidal marshes have been ...

  Citation × Citation Citation Abstract Copy Title: Juvenile coho salmon movement and migration through tide gates Author: Bass, Arthur Langer Tidal marshlands in the upper estuary ecotone provide essential habitat for juvenile salmonids. In this environment, salmonids grow rapidly and acclimate to saltwater. Worldwide, tidal marshes have been diked and drained to provide agricultural and residential land. Tide gates are one-way doors integrated into dike systems that prevent saltwater flooding and allow upland drainage to the estuary during low tide. By preventing tidal exchange, tide gates have significant upstream effects on water temperature and chemistry, plant and animal community structure, and geomorphology. Since they are closed most of the day and may be difficult to pass when open, tide gates may act as fish passage barriers for juvenile salmonids. They may also affect juvenile salmon migration timing by altering environmental variables that influence emigration rate in upstream habitats. We conducted our research in Coos Bay, one of the many Oregon estuaries with extensive use of tide gates. We studied three streams, one with a top-hinged tide gate, one with a side-hinged gate, and one without any tide gates that acted as our reference site. Our study species was coho salmon, Oncorhynchus kisutch, which may encounter tide gates both in the subyearling and smolt life stages in our study streams. Our objectives were to: 1) quantify upstream and downstream fish passage occurrence at all three sites, 2) determine whether juvenile coho salmon passage is associated with a specific range of gate conditions, and 3) identify any associations between coho smolt emigration rate and environmental variables that are influenced by tide gates. We installed stationary passive integrated transponder (PIT) antennae around both tide gates and a tidal channel in the non-gated stream to record the movement of PIT tagged juvenile coho salmon. Coho salmon smolts passed upstream most frequently at the non-gated channel (48% of all smolts detected at the array), next the side-hinged gate (28%), and lastly, the top-hinged gate (3%). Juvenile coho salmon passed more frequently at a specific range of gate angles and tailwater depths at both top hinged and side-hinged tide gates. Smolts passed downstream more frequently at greater gate angles and tailwater depths than available on average at both tide gates. Subyearlings passed upstream more frequently during small gate angles and a narrow range of tailwater depths at the top-hinged gate but did not pass more frequently under a particular range of conditions at the side-hinged gate. At the top-hinged gate, conditions favorable for subyearling upstream passage occurred towards the end of the gate open period and therefore subyearlings were severely limited in their opportunities for passage. At multiple sites, emigration rate was associated with environmental variables that may be altered by tide gates. Increases in water temperature were associated with an increasing likelihood of smolt emigration at multiple sites. At a tide gate that allowed upstream estuarine influence, increasing salinity was associated with a decreasing likelihood of emigration. Our results suggest that tide gates may interfere with salmonid movement and migration by creating physical barriers to fish passage and potentially influencing migratory timing by altering environmental variables. When installing or retrofitting tide gates, these factors should be taken into consideration since a tide gate's design may determine the severity of its effects on salmonids. Our work should be considered a case study and the findings should not be assumed to be transferable due to the great diversity of tide gate installations in use. We recommend further research, including a more in depth analysis of the affects of tide gates on subyearling coho salmon and an investigation of piscivorous predator exploitation of tide gates. Title: Juvenile coho salmon movement and migration through tide gates Author: Bass, Arthur Langer Tidal marshlands in the upper estuary ecotone provide essential habitat for juvenile salmonids. In this environment, salmonids grow rapidly and acclimate to saltwater. Worldwide, tidal marshes have been diked and drained to provide agricultural and residential land. Tide gates are one-way doors integrated into dike systems that prevent saltwater flooding and allow upland drainage to the estuary during low tide. By preventing tidal exchange, tide gates have significant upstream effects on water temperature and chemistry, plant and animal community structure, and geomorphology. Since they are closed most of the day and may be difficult to pass when open, tide gates may act as fish passage barriers for juvenile salmonids. They may also affect juvenile salmon migration timing by altering environmental variables that influence emigration rate in upstream habitats. We conducted our research in Coos Bay, one of the many Oregon estuaries with extensive use of tide gates. We studied three streams, one with a top-hinged tide gate, one with a side-hinged gate, and one without any tide gates that acted as our reference site. Our study species was coho salmon, Oncorhynchus kisutch, which may encounter tide gates both in the subyearling and smolt life stages in our study streams. Our objectives were to: 1) quantify upstream and downstream fish passage occurrence at all three sites, 2) determine whether juvenile coho salmon passage is associated with a specific range of gate conditions, and 3) identify any associations between coho smolt emigration rate and environmental variables that are influenced by tide gates. We installed stationary passive integrated transponder (PIT) antennae around both tide gates and a tidal channel in the non-gated stream to record the movement of PIT tagged juvenile coho salmon. Coho salmon smolts passed upstream most frequently at the non-gated channel (48% of all smolts detected at the array), next the side-hinged gate (28%), and lastly, the top-hinged gate (3%). Juvenile coho salmon passed more frequently at a specific range of gate angles and tailwater depths at both top hinged and side-hinged tide gates. Smolts passed downstream more frequently at greater gate angles and tailwater depths than available on average at both tide gates. Subyearlings passed upstream more frequently during small gate angles and a narrow range of tailwater depths at the top-hinged gate but did not pass more frequently under a particular range of conditions at the side-hinged gate. At the top-hinged gate, conditions favorable for subyearling upstream passage occurred towards the end of the gate open period and therefore subyearlings were severely limited in their opportunities for passage. At multiple sites, emigration rate was associated with environmental variables that may be altered by tide gates. Increases in water temperature were associated with an increasing likelihood of smolt emigration at multiple sites. At a tide gate that allowed upstream estuarine influence, increasing salinity was associated with a decreasing likelihood of emigration. Our results suggest that tide gates may interfere with salmonid movement and migration by creating physical barriers to fish passage and potentially influencing migratory timing by altering environmental variables. When installing or retrofitting tide gates, these factors should be taken into consideration since a tide gate's design may determine the severity of its effects on salmonids. Our work should be considered a case study and the findings should not be assumed to be transferable due to the great diversity of tide gate installations in use. We recommend further research, including a more in depth analysis of the affects of tide gates on subyearling coho salmon and an investigation of piscivorous predator exploitation of tide gates. Close

• 814. [Article] Effects of harvest and roads on in-stream wood abundance in the Blue River Basin, western Cascades, Oregon

  Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns ...

  Citation × Citation Citation Abstract Copy Title: Effects of harvest and roads on in-stream wood abundance in the Blue River Basin, western Cascades, Oregon Author: Czarnomski, Nicole M. Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns in streams of the Pacific Northwest. This study examined the relationships between wood in streams, timber harvest, and road building at large (>50 km² ) spatial and long (>25 year) temporal scales, based on longitudinal surveys of 25.2 km of stream length in five sub-basins of the Blue River Basin, Cascade Range, Oregon. In-stream wood was surveyed in six sampling sites, ranging from 1.6 km to 14.1 km in length along 2nd to 5th -order channels in public forests. Wood volumes, numbers of pieces of large wood, numbers of accumulations and timing of emplacement were determined at 50-m intervals. Wood volumes and numbers of pieces were expressed per unit of channel area in order to account for variations in channel width. Wood volumes and piece numbers were related to spatial data on harvest and road building using GIS. Analysis of variance (using SAS) tested how wood volumes and piece numbers were related to the presence of a harvest or road unit within 40 m of the stream, sampling site, timing of harvest, distance harvest was from the channel, and effects of natural processes. P-values for pairwise comparisons were adjusted using a Bonfenoni procedure. Distributed patch clearcutting and road construction were concentrated in the 1950's and 1960's in the Lookout Creek basin and 1960's to the 1980's in the Upper Blue River basin. A total of 66% (Cook Creek), 55% (Mack Creek), 53% (Lower Lookout), 37% (McRae Creek and Upper Lookout), and 7% (Quentin Creek) of stream length had harvests and/or roads within 40 m of the stream. Approximately 80% of the wood volume and 85% of the number of large pieces occurred in accumulations. Wood volumes were lower in 5th-order compared to 3rd -order streams. Lower Lookout (the only 5th-order channel) had significantly lower wood volumes (109 m³/ha) than all other locations (200-378 m³/ha, p<O.O5) and significantly lower numbers of large pieces (23 large pieces/ha) compared to all other locations (39 vs. 64 large pieces/ha, p<O.008). All other locations had fairly similar wood volumes and numbers of large pieces For all study sites combined, 50-m stream segments without harvests or roads had significantly higher volume (356 m³/ha) and number of large pieces (57 pieces/ha), than stream segments with harvests or roads within 40 m (80 to 157 m³/ha, p<O.O3; 19 to 39 pieces/ha, p<O.O4). Stream segments without harvests or roads (32 pieces/ha) also had significantly higher number of accumulations compared to stream segments with roads (16 pieces/ha, p<O.004), or compared to stream segments with harvest on one side and roads (16 pieces/ha, p<O.004). Distance a harvest was from the stream and timing of harvest did not appear to affect wood volume or number of large pieces. Harvests and roads were associated with decreases in wood abundance 50 m upstream and 50 m downstream of harvest units and road crossings. The 50-m stream segments immediately upstream (171.8 m³/ha) and downstream (191.6 m³/ha) of a section of stream with harvest and roads had significantly lower volume than the 50-m stream segments without harvest or roads (427.7 m³/ha, p<O. 1). Natural processes such as floods, windthrow, near-stream toppling, and debris flows from the last 50 years had not obscured the effects of harvest and roads on wood volume and number of pieces in stream channels of Lookout Creek and Blue River. The legacy of harvest and road activities was still apparent in in-stream wood patterns up to 50 years later in this site, which consisted of old-growth forest subjected to dispersed patch clearcutting, road construction, and salvage logging conducted in the 1950's to the 1980s. However, harvest, road, and salvage practices on public lands have changed since that period. Therefore, these results should be extrapolated to other sites only with careful consideration of site history. Title: Effects of harvest and roads on in-stream wood abundance in the Blue River Basin, western Cascades, Oregon Author: Czarnomski, Nicole M. Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns in streams of the Pacific Northwest. This study examined the relationships between wood in streams, timber harvest, and road building at large (>50 km² ) spatial and long (>25 year) temporal scales, based on longitudinal surveys of 25.2 km of stream length in five sub-basins of the Blue River Basin, Cascade Range, Oregon. In-stream wood was surveyed in six sampling sites, ranging from 1.6 km to 14.1 km in length along 2nd to 5th -order channels in public forests. Wood volumes, numbers of pieces of large wood, numbers of accumulations and timing of emplacement were determined at 50-m intervals. Wood volumes and numbers of pieces were expressed per unit of channel area in order to account for variations in channel width. Wood volumes and piece numbers were related to spatial data on harvest and road building using GIS. Analysis of variance (using SAS) tested how wood volumes and piece numbers were related to the presence of a harvest or road unit within 40 m of the stream, sampling site, timing of harvest, distance harvest was from the channel, and effects of natural processes. P-values for pairwise comparisons were adjusted using a Bonfenoni procedure. Distributed patch clearcutting and road construction were concentrated in the 1950's and 1960's in the Lookout Creek basin and 1960's to the 1980's in the Upper Blue River basin. A total of 66% (Cook Creek), 55% (Mack Creek), 53% (Lower Lookout), 37% (McRae Creek and Upper Lookout), and 7% (Quentin Creek) of stream length had harvests and/or roads within 40 m of the stream. Approximately 80% of the wood volume and 85% of the number of large pieces occurred in accumulations. Wood volumes were lower in 5th-order compared to 3rd -order streams. Lower Lookout (the only 5th-order channel) had significantly lower wood volumes (109 m³/ha) than all other locations (200-378 m³/ha, p<O.O5) and significantly lower numbers of large pieces (23 large pieces/ha) compared to all other locations (39 vs. 64 large pieces/ha, p<O.008). All other locations had fairly similar wood volumes and numbers of large pieces For all study sites combined, 50-m stream segments without harvests or roads had significantly higher volume (356 m³/ha) and number of large pieces (57 pieces/ha), than stream segments with harvests or roads within 40 m (80 to 157 m³/ha, p<O.O3; 19 to 39 pieces/ha, p<O.O4). Stream segments without harvests or roads (32 pieces/ha) also had significantly higher number of accumulations compared to stream segments with roads (16 pieces/ha, p<O.004), or compared to stream segments with harvest on one side and roads (16 pieces/ha, p<O.004). Distance a harvest was from the stream and timing of harvest did not appear to affect wood volume or number of large pieces. Harvests and roads were associated with decreases in wood abundance 50 m upstream and 50 m downstream of harvest units and road crossings. The 50-m stream segments immediately upstream (171.8 m³/ha) and downstream (191.6 m³/ha) of a section of stream with harvest and roads had significantly lower volume than the 50-m stream segments without harvest or roads (427.7 m³/ha, p<O. 1). Natural processes such as floods, windthrow, near-stream toppling, and debris flows from the last 50 years had not obscured the effects of harvest and roads on wood volume and number of pieces in stream channels of Lookout Creek and Blue River. The legacy of harvest and road activities was still apparent in in-stream wood patterns up to 50 years later in this site, which consisted of old-growth forest subjected to dispersed patch clearcutting, road construction, and salvage logging conducted in the 1950's to the 1980s. However, harvest, road, and salvage practices on public lands have changed since that period. Therefore, these results should be extrapolated to other sites only with careful consideration of site history. Close

• 815. [Article] Physiological ecology of juvenile Chinook salmon (Oncorhynchus tshawytscha) rearing in fluctuating salinity environments

  Estuaries provide juvenile salmonids with highly productive feeding grounds, refugia from tidal fluctuations and predators, and acclimation areas for smoltification. However, these dynamic, fluctuating ...

  Citation × Citation Citation Abstract Copy Title: Physiological ecology of juvenile Chinook salmon (Oncorhynchus tshawytscha) rearing in fluctuating salinity environments Author: Hackmann, Crystal R. Estuaries provide juvenile salmonids with highly productive feeding grounds, refugia from tidal fluctuations and predators, and acclimation areas for smoltification. However, these dynamic, fluctuating salinity environments may also be physiologically stressful to growing juvenile fish. In order to evaluate the costs and benefits of estuarine marshes to juvenile Chinook salmon, I observed habitat use, diet, and growth of fish in the Nehalem Estuary on the Oregon coast. I also examined physiological costs associated with salmon living in fluctuating salinities and growth rates in laboratory experiments. I collected growth, diet and osmoregulation information from juvenile Chinook salmon in three tidal marsh sites in the Nehalem Bay and from juveniles in the Nehalem River. Stomach contents indicated that a high proportion of the diet is derived from terrestrial prey. These allochthonous prey resources likely become available during the flood stages of tidal cycles when drift, emergent and terrestrial insects would become available from the grasses surrounding the water. This field study confirmed that juvenile Chinook salmon utilized fluctuating salinity habitats to feed on a wide range of items including terrestrial-derived resources. Although field studies indicate that fish in estuarine habitats grow well and have access to quality prey resources, experimental manipulations of salinities were used to quantify the physiological costs of residing in the freshwater-saltwater transitional zone. In the laboratory, I designed an experiment to investigate the physiological responses to fluctuating salinities. Experimental treatments consisted of freshwater (FW), saltwater (SW) (22-25%o); and a fluctuating salinity (SW/FW) (2 - 25%o). These treatments were based on typical salinity fluctuations found in estuarine habitats. I measured length, weight, plasma electrolytes and cortisol concentrations for indications of growth and osmoregulatory function. The fluctuating salinity treatment had a negative effect on growth rate and initial osmoregulatory ability when compared with constant freshwater and saltwater treatments. The results indicated that fluctuating salinities had a small but marginally significant reduction in growth rate, possibly due to the additional energetic requirements of switching between hyper- and hypo-osmoregulation. However, 24-hour saltwater challenge results indicated that all fish were capable of osmoregulating in full-strength seawater. In a second experiment, I manipulated feed consumption rates of juvenile spring Chinook salmon to investigate the effects of variable growth rates on osmoregulatory ability and to test the validity of RNA:DNA ratios as indication of recent growth. The treatments consisted of three different feeding rates: three tanks of fish fed 0.7 5% (LOW) body weight; three tanks fed 3% (HIGH) body weight; and three tanks were fasted (NONE) during the experiment. These laboratory results showed a significant difference in the osmoregulatory ability of the NONE treatment compared to the LOW and HIGH treatments which indicates that a reduction in caloric intake significantly effected osmoregulatory capabilities during a 24 hour saltwater challenge. Furthermore, this suggests that there is a minimum energetic requirement in order to maintain proper ion- and osmoregulation in marine conditions. Estuarine marshes have the potential to provide productive feeding grounds with sufficient prey input from terrestrial systems. However, utilization of these marshes in sub-optimal conditions could alter behavior or impair physiological condition of juvenile Chinook salmon prior to their seaward migration by providing insufficient prey resources in a potentially stressful, fluctuating environment. Therefore, the physiological costs associated with estuarine habitat use should be well understood in order to aid future restoration planning. Title: Physiological ecology of juvenile Chinook salmon (Oncorhynchus tshawytscha) rearing in fluctuating salinity environments Author: Hackmann, Crystal R. Estuaries provide juvenile salmonids with highly productive feeding grounds, refugia from tidal fluctuations and predators, and acclimation areas for smoltification. However, these dynamic, fluctuating salinity environments may also be physiologically stressful to growing juvenile fish. In order to evaluate the costs and benefits of estuarine marshes to juvenile Chinook salmon, I observed habitat use, diet, and growth of fish in the Nehalem Estuary on the Oregon coast. I also examined physiological costs associated with salmon living in fluctuating salinities and growth rates in laboratory experiments. I collected growth, diet and osmoregulation information from juvenile Chinook salmon in three tidal marsh sites in the Nehalem Bay and from juveniles in the Nehalem River. Stomach contents indicated that a high proportion of the diet is derived from terrestrial prey. These allochthonous prey resources likely become available during the flood stages of tidal cycles when drift, emergent and terrestrial insects would become available from the grasses surrounding the water. This field study confirmed that juvenile Chinook salmon utilized fluctuating salinity habitats to feed on a wide range of items including terrestrial-derived resources. Although field studies indicate that fish in estuarine habitats grow well and have access to quality prey resources, experimental manipulations of salinities were used to quantify the physiological costs of residing in the freshwater-saltwater transitional zone. In the laboratory, I designed an experiment to investigate the physiological responses to fluctuating salinities. Experimental treatments consisted of freshwater (FW), saltwater (SW) (22-25%o); and a fluctuating salinity (SW/FW) (2 - 25%o). These treatments were based on typical salinity fluctuations found in estuarine habitats. I measured length, weight, plasma electrolytes and cortisol concentrations for indications of growth and osmoregulatory function. The fluctuating salinity treatment had a negative effect on growth rate and initial osmoregulatory ability when compared with constant freshwater and saltwater treatments. The results indicated that fluctuating salinities had a small but marginally significant reduction in growth rate, possibly due to the additional energetic requirements of switching between hyper- and hypo-osmoregulation. However, 24-hour saltwater challenge results indicated that all fish were capable of osmoregulating in full-strength seawater. In a second experiment, I manipulated feed consumption rates of juvenile spring Chinook salmon to investigate the effects of variable growth rates on osmoregulatory ability and to test the validity of RNA:DNA ratios as indication of recent growth. The treatments consisted of three different feeding rates: three tanks of fish fed 0.7 5% (LOW) body weight; three tanks fed 3% (HIGH) body weight; and three tanks were fasted (NONE) during the experiment. These laboratory results showed a significant difference in the osmoregulatory ability of the NONE treatment compared to the LOW and HIGH treatments which indicates that a reduction in caloric intake significantly effected osmoregulatory capabilities during a 24 hour saltwater challenge. Furthermore, this suggests that there is a minimum energetic requirement in order to maintain proper ion- and osmoregulation in marine conditions. Estuarine marshes have the potential to provide productive feeding grounds with sufficient prey input from terrestrial systems. However, utilization of these marshes in sub-optimal conditions could alter behavior or impair physiological condition of juvenile Chinook salmon prior to their seaward migration by providing insufficient prey resources in a potentially stressful, fluctuating environment. Therefore, the physiological costs associated with estuarine habitat use should be well understood in order to aid future restoration planning. Close

• 816. [Article] Incubation patterns, parental roles, and nest survival of black oystercatchers (Haematopus bachmani) : influences of environmental processes and potential disturbance stimuli

  Shorebirds display great variation in mating systems and breed in dynamic environments that are increasingly subject to human threats worldwide. In order to adequately assess productivity and demography ...

  Citation × Citation Citation Abstract Copy Title: Incubation patterns, parental roles, and nest survival of black oystercatchers (Haematopus bachmani) : influences of environmental processes and potential disturbance stimuli Author: Spiegel, Caleb S. Shorebirds display great variation in mating systems and breed in dynamic environments that are increasingly subject to human threats worldwide. In order to adequately assess productivity and demography of shorebird populations, it is important to understand factors that influence patterns of parental care and reproductive success. The Black Oystercatcher (Haematopus bachmani) is a shorebird species of concern and an indicator of the health of intertidal ecosystems. Much information on breeding biology is lacking for the species, though it is reported to regularly experience low reproductive success and may be vulnerable to human disturbance during nesting. This thesis examines relationships among natural and human processes related to incubation and nest success of Black Oystercatchers in a high density breeding area of Alaska, experiencing increasing human recreational activity. In 2005 and 2006, oystercatcher nests were continuously monitored with video cameras to investigate the association of cyclical (time of day, tide, ambient temperature, seasonality) and stochastic (natural/human disturbance) processes with incubation patterns (nest attendance, incubation bout length, incubation recess rate) and sex roles. Review of over 3,000 hours of footage from 13 molecularly sexed nesting pairs revealed complimentary bi-parental care with differing roles between sexes. Females allocated more to nest attendance and had longer incubation bout lengths, indicating a greater investment in incubation compared to males. Males responded more frequently to nest area disturbance stimuli compared to females, indicating that males invest more in nest defense. Incubation patterns were also influenced by tide stage and height, ambient temperature, and disturbance stimuli. Incubation bout lengths nearly doubled at night, independent of sex. Longer nocturnal bouts may minimize parental activity near the nest during periods of increased predation risk when incubation duty changes could reveal the presence of nests to nocturnal predators. Video footage was also used to document the types and frequencies of human and predator stimuli, and extreme weather and tide episodes encountered near oystercatcher nests, and the effect of these potential disturbance stimuli on incubation behavior and nest success. Nearly 800 potential disturbance stimulus events were documented within 25 m of video monitored nests. Other bird species were the most frequently observed type of potential disturbance, but were largely ignored by incubating oystercatchers. Oystercatchers were most frequently disturbed (as evidenced by displacement from a nest) by conspecifics and humans, with nests left unattended for longer periods following human disturbance than any other disturbance type. Although infrequent, a high proportion of mammal observations also resulted in oystercatchers flushing from their nests. Changes in incubation behavior due to disturbance were not found to affect nest success, nor did nest success decrease with proximity to areas of frequent human recreational activity. Nocturnal nest predation by mustelids and nighttime flood tides accounted for six of seven nest failures recorded on video, even though nights were disproportionately short during the study. Thus, future shorebird breeding studies should assess causes of nest failure from latent nocturnal causes, rather than just obvious diurnal causes. With the analysis of extensive nest observation data this study identified natural and anthropogenic processes that affected incubation patterns of an uncommon shorebird species, specially adapted to a dynamic nesting environment. Results elucidate factors influencing oystercatcher life history and lay the groundwork for further investigation into the effects of human disturbance on nest success and demography of the Black Oystercatcher. Future research should investigate nest success in breeding areas experiencing higher levels of disturbance, include post-hatching breeding stages, and be conducted over multiple breeding seasons. Title: Incubation patterns, parental roles, and nest survival of black oystercatchers (Haematopus bachmani) : influences of environmental processes and potential disturbance stimuli Author: Spiegel, Caleb S. Shorebirds display great variation in mating systems and breed in dynamic environments that are increasingly subject to human threats worldwide. In order to adequately assess productivity and demography of shorebird populations, it is important to understand factors that influence patterns of parental care and reproductive success. The Black Oystercatcher (Haematopus bachmani) is a shorebird species of concern and an indicator of the health of intertidal ecosystems. Much information on breeding biology is lacking for the species, though it is reported to regularly experience low reproductive success and may be vulnerable to human disturbance during nesting. This thesis examines relationships among natural and human processes related to incubation and nest success of Black Oystercatchers in a high density breeding area of Alaska, experiencing increasing human recreational activity. In 2005 and 2006, oystercatcher nests were continuously monitored with video cameras to investigate the association of cyclical (time of day, tide, ambient temperature, seasonality) and stochastic (natural/human disturbance) processes with incubation patterns (nest attendance, incubation bout length, incubation recess rate) and sex roles. Review of over 3,000 hours of footage from 13 molecularly sexed nesting pairs revealed complimentary bi-parental care with differing roles between sexes. Females allocated more to nest attendance and had longer incubation bout lengths, indicating a greater investment in incubation compared to males. Males responded more frequently to nest area disturbance stimuli compared to females, indicating that males invest more in nest defense. Incubation patterns were also influenced by tide stage and height, ambient temperature, and disturbance stimuli. Incubation bout lengths nearly doubled at night, independent of sex. Longer nocturnal bouts may minimize parental activity near the nest during periods of increased predation risk when incubation duty changes could reveal the presence of nests to nocturnal predators. Video footage was also used to document the types and frequencies of human and predator stimuli, and extreme weather and tide episodes encountered near oystercatcher nests, and the effect of these potential disturbance stimuli on incubation behavior and nest success. Nearly 800 potential disturbance stimulus events were documented within 25 m of video monitored nests. Other bird species were the most frequently observed type of potential disturbance, but were largely ignored by incubating oystercatchers. Oystercatchers were most frequently disturbed (as evidenced by displacement from a nest) by conspecifics and humans, with nests left unattended for longer periods following human disturbance than any other disturbance type. Although infrequent, a high proportion of mammal observations also resulted in oystercatchers flushing from their nests. Changes in incubation behavior due to disturbance were not found to affect nest success, nor did nest success decrease with proximity to areas of frequent human recreational activity. Nocturnal nest predation by mustelids and nighttime flood tides accounted for six of seven nest failures recorded on video, even though nights were disproportionately short during the study. Thus, future shorebird breeding studies should assess causes of nest failure from latent nocturnal causes, rather than just obvious diurnal causes. With the analysis of extensive nest observation data this study identified natural and anthropogenic processes that affected incubation patterns of an uncommon shorebird species, specially adapted to a dynamic nesting environment. Results elucidate factors influencing oystercatcher life history and lay the groundwork for further investigation into the effects of human disturbance on nest success and demography of the Black Oystercatcher. Future research should investigate nest success in breeding areas experiencing higher levels of disturbance, include post-hatching breeding stages, and be conducted over multiple breeding seasons. Close

• 817. [Article] Giant otters (Pteronura brasiliensis) and humans in the lower Yasuní Basin, Ecuador : spacio-temporal activity patterns and their relevance for conservation

  Giant otters (Pteronura brasiliensis) and humans in the Lower Yasuní Basin (Ecuador) have similar food and space requirements: they consume comparable arrays of fish species, and they use similar aquatic ...

  Citation × Citation Citation Abstract Copy Title: Giant otters (Pteronura brasiliensis) and humans in the lower Yasuní Basin, Ecuador : spacio-temporal activity patterns and their relevance for conservation Author: Carrera-Ubidia, Paola M. Giant otters (Pteronura brasiliensis) and humans in the Lower Yasuní Basin (Ecuador) have similar food and space requirements: they consume comparable arrays of fish species, and they use similar aquatic and terrestrial habitats. Resource partitioning could facilitate coexistence by allowing each species exclusive access to some resources. My research examines the correlations between the use of spatial resources by giant otters and humans and the hydrological pulse of their ecosystem. My objectives were (1) to estimate the extent of terrestrial and aquatic habitat available for giant otters and humans;(2) to recognize the main patterns of space occupancy and its overlap between them; (3)to explain these patterns in relation to natural gradients in the watershed; (4) to describe the giant otter’s diet; and (5) to depict the foraging activities of giant otters and humans relative to the distribution of prey. Between October 2004 and March 2005, I surveyed the Jatuncocha and Tambococha Creeks (Yasuní National Park) for direct and indirect signs of giant otters and humans, and I collected giant otter scat. Habitat availability was estimated by a geo-referenced map model that integrated virtual and field data, portraying four seasonal scenarios. Space use overlaps between giant otters and humans are a function of water level and the distance between terrestrial and aquatic habitats. The floodplain comprises 43% of the total study area during the flooding season, and is reduced to 25% of the total area at minimum water levels. Polygons obtained containing suitable habitat for giant otters are in average 41% larger than those obtained for humans; these contain areas that are inaccessible to humans (isolated pools and swamps, tributaries, and the upper portions of the main channel). Differences in space availability for and use by giant otters and humans depend on water level fluctuations. Area occupancy by both species is proportional to the estimated availability; but more so for giant otters, as humans increase area occupancy during the driest periods. Giant otter activity was primarily concentrated around the largest tributaries of each creek, and secondarily wherever the distance between suitable terrestrial and aquatic habitat was smaller. Human activity signs were distributed along the hydrographical gradient, i.e. in the lower portion of the Jatuncocha System (lagoon) or in the middle portion of the Tambococha Creek (large tributary). To identify correlations between habitat use by giant otters and humans and prey availability, I analyzed scat samples and collected fish along several creek stretches. Giant otters consumed at least 47 of the 73 species available for them. Identifiable hard parts in the scat samples consisted primarily of Hoplias malabaricus (11.3%), Hypselecara termporalis (5.3%), Acestrorrhynchus sp. and Prochilodus nigricans (4.9% each). Foraging activity of giant otters was positively correlated with fish abundance and relative diversity, with some exceptions. Human activity patterns were related to fish abundance and diversity in Tambococha, but showed less correlation to fish distribution in Jatuncocha. Overlap in resource availability and habitat use by otters and humans is highly variable. In the floodplain, extent and depth are critical variables that determine the distribution of resources in time and space, as well as the amount of resource partitioning possible. Competitive interactions during stressful conditions could be reduced by ensuring the availability of exclusive resources for giant otters during the driest periods, allocating suitable habitats within a short distance from one another along the longitudinal gradient of each watershed. Locally adapted and biologically sound regulations within this and comparable areas of the YNP could promote the persistence of giant otters without compromising the well-being of the local human inhabitants. Title: Giant otters (Pteronura brasiliensis) and humans in the lower Yasuní Basin, Ecuador : spacio-temporal activity patterns and their relevance for conservation Author: Carrera-Ubidia, Paola M. Giant otters (Pteronura brasiliensis) and humans in the Lower Yasuní Basin (Ecuador) have similar food and space requirements: they consume comparable arrays of fish species, and they use similar aquatic and terrestrial habitats. Resource partitioning could facilitate coexistence by allowing each species exclusive access to some resources. My research examines the correlations between the use of spatial resources by giant otters and humans and the hydrological pulse of their ecosystem. My objectives were (1) to estimate the extent of terrestrial and aquatic habitat available for giant otters and humans;(2) to recognize the main patterns of space occupancy and its overlap between them; (3)to explain these patterns in relation to natural gradients in the watershed; (4) to describe the giant otter’s diet; and (5) to depict the foraging activities of giant otters and humans relative to the distribution of prey. Between October 2004 and March 2005, I surveyed the Jatuncocha and Tambococha Creeks (Yasuní National Park) for direct and indirect signs of giant otters and humans, and I collected giant otter scat. Habitat availability was estimated by a geo-referenced map model that integrated virtual and field data, portraying four seasonal scenarios. Space use overlaps between giant otters and humans are a function of water level and the distance between terrestrial and aquatic habitats. The floodplain comprises 43% of the total study area during the flooding season, and is reduced to 25% of the total area at minimum water levels. Polygons obtained containing suitable habitat for giant otters are in average 41% larger than those obtained for humans; these contain areas that are inaccessible to humans (isolated pools and swamps, tributaries, and the upper portions of the main channel). Differences in space availability for and use by giant otters and humans depend on water level fluctuations. Area occupancy by both species is proportional to the estimated availability; but more so for giant otters, as humans increase area occupancy during the driest periods. Giant otter activity was primarily concentrated around the largest tributaries of each creek, and secondarily wherever the distance between suitable terrestrial and aquatic habitat was smaller. Human activity signs were distributed along the hydrographical gradient, i.e. in the lower portion of the Jatuncocha System (lagoon) or in the middle portion of the Tambococha Creek (large tributary). To identify correlations between habitat use by giant otters and humans and prey availability, I analyzed scat samples and collected fish along several creek stretches. Giant otters consumed at least 47 of the 73 species available for them. Identifiable hard parts in the scat samples consisted primarily of Hoplias malabaricus (11.3%), Hypselecara termporalis (5.3%), Acestrorrhynchus sp. and Prochilodus nigricans (4.9% each). Foraging activity of giant otters was positively correlated with fish abundance and relative diversity, with some exceptions. Human activity patterns were related to fish abundance and diversity in Tambococha, but showed less correlation to fish distribution in Jatuncocha. Overlap in resource availability and habitat use by otters and humans is highly variable. In the floodplain, extent and depth are critical variables that determine the distribution of resources in time and space, as well as the amount of resource partitioning possible. Competitive interactions during stressful conditions could be reduced by ensuring the availability of exclusive resources for giant otters during the driest periods, allocating suitable habitats within a short distance from one another along the longitudinal gradient of each watershed. Locally adapted and biologically sound regulations within this and comparable areas of the YNP could promote the persistence of giant otters without compromising the well-being of the local human inhabitants. Close

• 818. [Article] Sediment accumulation and human impacts in Tillamook Bay, Oregon

  Tillamook Bay is the second largest estuary on the Oregon coast, and concerns have been raised whether human induced impacts have been responsible for the perceived increase in sedimentation rates during ...

  Citation × Citation Citation Abstract Copy Title: Sediment accumulation and human impacts in Tillamook Bay, Oregon Author: Styllas, Michael N. Tillamook Bay is the second largest estuary on the Oregon coast, and concerns have been raised whether human induced impacts have been responsible for the perceived increase in sedimentation rates during the past century. Major land-use practices within the five watersheds of the Bay include logging, forest fires, the construction of forest roads, the placement of dikes along the channels of the main rivers and in the estuary, the removal of riparian vegetation, and the construction of jetties at the tidal inlet. Each of these practices has led to impacts on the entire ecosystem of the watersheds and the Bay, but this study focuses on the effects of human disturbances on the Bay's sediment accumulation. This study examines in detail the land-use practices that have occurred in the watersheds, on the beaches, and in the estuary, focusing on those that have had a direct impact on the sedimentation regime of the Bay. One goal of the study is to assess the relative roles of natural processes versus human impacts on the sedimentation. A general description of the physical characteristics of Tillamook Bay and its surroundings is included, and a brief discussion is provided about the tectonic setting of the Northwest Coast, including its history of subduction earthquakes and the associate sea-level changes. Also provided is a summary of the existing information concerning the arrival of Indians and their environmental impacts, followed by a more detailed account of the major impacts that have resulted from the settlement of the Euro-Americans in the Tillamook area, in the 1850's. The study then focuses on the description of the watersheds from a geomorphologic point of view, and the important land-use practices that may have affected sediment yields during the past century. Analyses of the hydrology of the Tillamook Bay watersheds are included, and the relations between annual water yields and total precipitation are examined in distinct time intervals, each corresponding to a different period with different amounts of land uses. The results of these hydrology analyses suggest that the Tillamook watershed gradually recovered from a period of major disturbances (from 1933 to 1955) to more normal conditions (from 1977 to 1998). In addition, this part of the study attempts to quantify the sediment transport regime of the rivers draining the watershed by using a hydraulic model that is based on the principle of stream power, and on considerations of availability of transported material. Application of this model during the 1933-1955 period for the major rivers suggests an average sediment yield on the order of 410,540 tons/year, but most important are the relative changes of the delivered sediment through time. The results of the model suggest a 1.6-factor decrease of the amount of river sediments from the Heavily Impacted Period (1933-1955) of major disturbances to the Normal Period (1977- 1998). The spatial variations of beach and river derived sediments throughout the Bay are determined from textural and mineralogical analyses of surface sediment samples, with the beach sands dominating the area close to the inlet and the river derived sands being mainly deposited at the southeast and northeast parts of the Bay. The relative contributions of these two major sources of sediment were found to be 60% for the marine beach and 40% for the river sands. Further attempt is made to distinguish between the sand transported into the Bay from the individual rivers, and to determine the main processes that are responsible for the dispersion of sediments within the Bay. The attempts to distinguish sands contributed by the individual rivers involved modal analyses of the frequency curves of the surface sediment samples, and the results mainly suggest a grain-size increase away from the mouth of the rivers as a result of sediment reworking by estuarine processes following its initial deposition during episodic river flooding. The main processes that control the dispersion of sediments and their deposition within the Bay were identified by using factor analysis, the results of which suggest that various estuarine processes are responsible for the observed dispersal patterns. A brief review is provided of the study undertaken by Dr. James McManus for the collection and analyses of core samples from Tillamook Bay. Down-core geochemical analyses of major and minor elements indicate that there have been times of episodic input of marine sediment in the central and western portions of the Bay, which is a result of either periodic breaching or washover of Bayocean Spit, so that the beach sand source was more important in the past. This episodic input of marine sand as inferred from the down-core geochemical variations was related to the most recent subduction earthquake, which occurred on January 26th, 1700. Finally, a summary of the results and conclusions of different aspects of this study is presented, so that sedimentation in Tillamook Bay can be viewed as an integrated process involving the watersheds, the estuary, and the ocean beaches. Title: Sediment accumulation and human impacts in Tillamook Bay, Oregon Author: Styllas, Michael N. Tillamook Bay is the second largest estuary on the Oregon coast, and concerns have been raised whether human induced impacts have been responsible for the perceived increase in sedimentation rates during the past century. Major land-use practices within the five watersheds of the Bay include logging, forest fires, the construction of forest roads, the placement of dikes along the channels of the main rivers and in the estuary, the removal of riparian vegetation, and the construction of jetties at the tidal inlet. Each of these practices has led to impacts on the entire ecosystem of the watersheds and the Bay, but this study focuses on the effects of human disturbances on the Bay's sediment accumulation. This study examines in detail the land-use practices that have occurred in the watersheds, on the beaches, and in the estuary, focusing on those that have had a direct impact on the sedimentation regime of the Bay. One goal of the study is to assess the relative roles of natural processes versus human impacts on the sedimentation. A general description of the physical characteristics of Tillamook Bay and its surroundings is included, and a brief discussion is provided about the tectonic setting of the Northwest Coast, including its history of subduction earthquakes and the associate sea-level changes. Also provided is a summary of the existing information concerning the arrival of Indians and their environmental impacts, followed by a more detailed account of the major impacts that have resulted from the settlement of the Euro-Americans in the Tillamook area, in the 1850's. The study then focuses on the description of the watersheds from a geomorphologic point of view, and the important land-use practices that may have affected sediment yields during the past century. Analyses of the hydrology of the Tillamook Bay watersheds are included, and the relations between annual water yields and total precipitation are examined in distinct time intervals, each corresponding to a different period with different amounts of land uses. The results of these hydrology analyses suggest that the Tillamook watershed gradually recovered from a period of major disturbances (from 1933 to 1955) to more normal conditions (from 1977 to 1998). In addition, this part of the study attempts to quantify the sediment transport regime of the rivers draining the watershed by using a hydraulic model that is based on the principle of stream power, and on considerations of availability of transported material. Application of this model during the 1933-1955 period for the major rivers suggests an average sediment yield on the order of 410,540 tons/year, but most important are the relative changes of the delivered sediment through time. The results of the model suggest a 1.6-factor decrease of the amount of river sediments from the Heavily Impacted Period (1933-1955) of major disturbances to the Normal Period (1977- 1998). The spatial variations of beach and river derived sediments throughout the Bay are determined from textural and mineralogical analyses of surface sediment samples, with the beach sands dominating the area close to the inlet and the river derived sands being mainly deposited at the southeast and northeast parts of the Bay. The relative contributions of these two major sources of sediment were found to be 60% for the marine beach and 40% for the river sands. Further attempt is made to distinguish between the sand transported into the Bay from the individual rivers, and to determine the main processes that are responsible for the dispersion of sediments within the Bay. The attempts to distinguish sands contributed by the individual rivers involved modal analyses of the frequency curves of the surface sediment samples, and the results mainly suggest a grain-size increase away from the mouth of the rivers as a result of sediment reworking by estuarine processes following its initial deposition during episodic river flooding. The main processes that control the dispersion of sediments and their deposition within the Bay were identified by using factor analysis, the results of which suggest that various estuarine processes are responsible for the observed dispersal patterns. A brief review is provided of the study undertaken by Dr. James McManus for the collection and analyses of core samples from Tillamook Bay. Down-core geochemical analyses of major and minor elements indicate that there have been times of episodic input of marine sediment in the central and western portions of the Bay, which is a result of either periodic breaching or washover of Bayocean Spit, so that the beach sand source was more important in the past. This episodic input of marine sand as inferred from the down-core geochemical variations was related to the most recent subduction earthquake, which occurred on January 26th, 1700. Finally, a summary of the results and conclusions of different aspects of this study is presented, so that sedimentation in Tillamook Bay can be viewed as an integrated process involving the watersheds, the estuary, and the ocean beaches. Close

• 819. [Article] Some techniques for determining fecal output and digestibility of range forage by cattle

  A Cr₂0₃, and cellulose fibre mixture was used with cattle, in three grazing and two semi-restricted experiments, to study the mode of its excretion, the possibility of using it in a once-daily dosing and grab-sample ...

  Citation × Citation Citation Abstract Copy Title: Some techniques for determining fecal output and digestibility of range forage by cattle Author: Pryor, William Joseph A Cr₂0₃, and cellulose fibre mixture was used with cattle, in three grazing and two semi-restricted experiments, to study the mode of its excretion, the possibility of using it in a once-daily dosing and grab-sample regime to estimate fecal output and in a field experiment to test a hypothesis involving the measurement of forage intake. The cattle consumed forages available in the sagebrush-bunchgrass region of Eastern Oregon, in which region the experiments were conducted. Cr₂0₃-Cellulose was fed to groups of three steers grazing immature crested wheatgrass, (Agropyron desertorum) in Experiment 1, or when it was mature along with regrowth in Experiment 2, either once a day at 8 a.m. or twice daily at 8 a.m. and 4 p.m. Twice a day grab sampling was carried out from 3-18 days after commencement of dosing with total collections from days 3-8 and 13-18. Estimated fecal outputs based on fecal grab sample concentrations at 8 a.m. alone, or the mean of 8 a.m. and 4 p.m. values were calculated in both experiments. Cr₂0₃ recoveries in Experiment 1 were low, ranging from 71.1-85.4 percent, with individual animals varying little between collection periods. Estimated fecal dry matter output was high in both groups for both collection periods and both sampling time methods, ranging from 115.7-187.3 percent. Standard errors of the mean (S.E.) were high in the 8 a.m. group in both collection periods, though not in the twice-daily group. Recoveries in Experiment 2 varied from 94.9-107.6 percent with an overall mean of 100.8 percent. The ratio of estimated fecal dry matter to that collected had high S.E.'s in the first period but gave the following results in the second period: 84.3 percent ± 4.5 percent S.E. for 8 a.m. dosing and sampling; 95.0 percent ± 1.5 percent for 8 a.m. and 4 p.m. dosing with 8 a.m. sampling; 97.1 percent ± 3.8 percent for 8 a.m. dosing and 8 a.m. and 4 p.m. sampling and 95.6 percent ± 2.0 percent for 8 a.m. and 4 p.m. dosing and sampling. The four-hourly Cr₂0₃ excretion curve of two groups of two long yearling heifers, two months pregnant, having continued access to flood meadow hay, was established by either once or twice daily dosing. The group dosed, once daily showed a relatively regular diurnal pattern, the twice-daily dosed group less so. The ratio of 8 a.m., and mean of 8 a.m. and 4 p.m. fecal Cr₂0₃ levels to daily mean four-hourly levels was established over a five-day period and showed a very close relationship to percentage estimates obtained in Experiment 2 for the 8 a.m. dosed and sampled group and to a slightly lesser extent to the other three groups. The excretion curve from a single ten gram dose of Cr₂0₃ as Cr₂0₃-Cellulose in two steers showed appreciable Cr₂0₃ in the feces within ten hours, a peak from approximately 18-26 hours in the better steer and levels near the limit of analytical accuracy from three to five days. The hypothesis, that poorer growth observed from forced feeding of common salt late in the grazing season was due to depressed forage intake, was rejected, using Lancaster's fecal nitrogen method for determining digestibility and once-daily Cr₂0₃ dosing and sampling with corrections obtained from Experiment 2 for fecal output to measure forage intake. Grab sample Cr₂0₃ concentration was significantly higher in the morning sample than the afternoon in all experiments. Coefficients of variation were higher in the morning for once daily dosing and higher in the afternoon in twice daily dosing. A series of 12 animal experiments and two simplified laboratory experiments were used to determine whether small nylon or cellulose acetate bags placed in the rumen could be passed through the alimentary tract and used as a possible method of measuring over-all forage digestibility. Bags tied to the fistula bung by nylon line were recovered intact at ten days. Rumen evacuation in cattle showed that nearly all bags placed free in the rumen had disappeared by three days with evidence of regurgitation on three occasions and only two free, intact bags. Sheep experiments by dosing and direct surgical placement in the rumen confirmed that regurgitation occurred. In a final slaughter experiment colored polyethylene and glass beads showed most, if not all, bags had been broken before reaching the reticulo-omasal orifice. All experimental observations on the fate of the bags are consistent with the following explanation. The bags in the rumen are subject to regurgitation; they cannot leave the rumen until this happens, following which the fragments are swallowed and are of a specific gravity and size that ensures their passage through the reticulo-omasal orifice. However, they are then dissolved in the acid environment of the lower stomachs. Although the problems of using the bag technique appear insurmountable, the manner of bag movements is believed to be fully understood. Title: Some techniques for determining fecal output and digestibility of range forage by cattle Author: Pryor, William Joseph A Cr₂0₃, and cellulose fibre mixture was used with cattle, in three grazing and two semi-restricted experiments, to study the mode of its excretion, the possibility of using it in a once-daily dosing and grab-sample regime to estimate fecal output and in a field experiment to test a hypothesis involving the measurement of forage intake. The cattle consumed forages available in the sagebrush-bunchgrass region of Eastern Oregon, in which region the experiments were conducted. Cr₂0₃-Cellulose was fed to groups of three steers grazing immature crested wheatgrass, (Agropyron desertorum) in Experiment 1, or when it was mature along with regrowth in Experiment 2, either once a day at 8 a.m. or twice daily at 8 a.m. and 4 p.m. Twice a day grab sampling was carried out from 3-18 days after commencement of dosing with total collections from days 3-8 and 13-18. Estimated fecal outputs based on fecal grab sample concentrations at 8 a.m. alone, or the mean of 8 a.m. and 4 p.m. values were calculated in both experiments. Cr₂0₃ recoveries in Experiment 1 were low, ranging from 71.1-85.4 percent, with individual animals varying little between collection periods. Estimated fecal dry matter output was high in both groups for both collection periods and both sampling time methods, ranging from 115.7-187.3 percent. Standard errors of the mean (S.E.) were high in the 8 a.m. group in both collection periods, though not in the twice-daily group. Recoveries in Experiment 2 varied from 94.9-107.6 percent with an overall mean of 100.8 percent. The ratio of estimated fecal dry matter to that collected had high S.E.'s in the first period but gave the following results in the second period: 84.3 percent ± 4.5 percent S.E. for 8 a.m. dosing and sampling; 95.0 percent ± 1.5 percent for 8 a.m. and 4 p.m. dosing with 8 a.m. sampling; 97.1 percent ± 3.8 percent for 8 a.m. dosing and 8 a.m. and 4 p.m. sampling and 95.6 percent ± 2.0 percent for 8 a.m. and 4 p.m. dosing and sampling. The four-hourly Cr₂0₃ excretion curve of two groups of two long yearling heifers, two months pregnant, having continued access to flood meadow hay, was established by either once or twice daily dosing. The group dosed, once daily showed a relatively regular diurnal pattern, the twice-daily dosed group less so. The ratio of 8 a.m., and mean of 8 a.m. and 4 p.m. fecal Cr₂0₃ levels to daily mean four-hourly levels was established over a five-day period and showed a very close relationship to percentage estimates obtained in Experiment 2 for the 8 a.m. dosed and sampled group and to a slightly lesser extent to the other three groups. The excretion curve from a single ten gram dose of Cr₂0₃ as Cr₂0₃-Cellulose in two steers showed appreciable Cr₂0₃ in the feces within ten hours, a peak from approximately 18-26 hours in the better steer and levels near the limit of analytical accuracy from three to five days. The hypothesis, that poorer growth observed from forced feeding of common salt late in the grazing season was due to depressed forage intake, was rejected, using Lancaster's fecal nitrogen method for determining digestibility and once-daily Cr₂0₃ dosing and sampling with corrections obtained from Experiment 2 for fecal output to measure forage intake. Grab sample Cr₂0₃ concentration was significantly higher in the morning sample than the afternoon in all experiments. Coefficients of variation were higher in the morning for once daily dosing and higher in the afternoon in twice daily dosing. A series of 12 animal experiments and two simplified laboratory experiments were used to determine whether small nylon or cellulose acetate bags placed in the rumen could be passed through the alimentary tract and used as a possible method of measuring over-all forage digestibility. Bags tied to the fistula bung by nylon line were recovered intact at ten days. Rumen evacuation in cattle showed that nearly all bags placed free in the rumen had disappeared by three days with evidence of regurgitation on three occasions and only two free, intact bags. Sheep experiments by dosing and direct surgical placement in the rumen confirmed that regurgitation occurred. In a final slaughter experiment colored polyethylene and glass beads showed most, if not all, bags had been broken before reaching the reticulo-omasal orifice. All experimental observations on the fate of the bags are consistent with the following explanation. The bags in the rumen are subject to regurgitation; they cannot leave the rumen until this happens, following which the fragments are swallowed and are of a specific gravity and size that ensures their passage through the reticulo-omasal orifice. However, they are then dissolved in the acid environment of the lower stomachs. Although the problems of using the bag technique appear insurmountable, the manner of bag movements is believed to be fully understood. Close

• 820. [Article] Understanding Public Perceptions of Post-Wildfire Landscape Recovery

  Forest disturbances, such as wildfires, pine beetle outbreaks, and floods are important features of many landscapes and ecosystems. Many disturbances are increasing in size, frequency, and intensity due ...

  Citation × Citation Citation Abstract Copy Title: Understanding Public Perceptions of Post-Wildfire Landscape Recovery Author: Kooistra, Chad Forest disturbances, such as wildfires, pine beetle outbreaks, and floods are important features of many landscapes and ecosystems. Many disturbances are increasing in size, frequency, and intensity due to changing climates and land management decisions. The changing ecological and aesthetic conditions following a disturbance can lead to negative short- and long-term social impacts. This dissertation research examines one aspect of the relationship between people and their environment in the context of forest disturbances and landscape changes. Specifically, it explores how people perceive a changing landscape after a forest disturbance, a trajectory referred to here as landscape recovery. After describing the larger context of forest disturbances in the introductory chapter, with a focus on wildfires, my second dissertation chapter developed a conceptual framework for understanding how people perceive post-disturbance landscape recovery. It examined the social factors that are most likely to influence those perceptions based on literature from various disciplines. These factors included visual cues and aesthetic preferences, landscape values and connections, and beliefs about the ecological role of disturbances. I described how the concepts and methodological approaches from mental models and social representations traditions help depict and explain how perceptions of landscape recovery can be studied in a way that explores the process shaping the perceptions. I explained how these perceptions likely exist along a spectrum from more simple perceptions focused on aesthetic judgments to more complex perceptions based more on ecological knowledge. I then proposed a research agenda to further investigate this framework, along with a summary of management considerations. The third chapter empirically explored the framework from the previous chapter by applying social representations theory (SRT) to qualitative research in Montana about how people perceive post-wildfire landscape recovery. I examined the mechanistic (i.e., anchoring and objectification) and structural (i.e., central core and peripheral elements) aspects of representations by integrating the factors proposed earlier as most influential in affecting perceptions of recovery. Interviews were conducted in 2014 with 30 residents who experienced the 2012 Dahl Fire, near Roundup, MT. Participants were purposively selected to represent a range of the factors described in Chapter 2. The main propositions from Chapter 2 were explored in the data collection and analysis steps. The core of all respondents' representations was centered on the concept of "Mother Nature." The factors identified in Chapter 2 further shaped representations uniquely across the two main groups of residents (rural lifestyle and working landscape residents) through the anchoring and objectification processes. People's representations about recovery were anchored in general beliefs about the past ecological and socio-cultural role of fire in the landscape as influenced by their past experiences and knowledge about ecological disturbances. Interpretations of different aspects of the landscape, including vegetation composition and key ecosystem functions, were filtered through people's values for the landscape and their specific beliefs about how the fire affected the landscape. This led to variation in specific notions of what constitutes a recovered landscape across the two main social groups there. These findings are discussed in the context of SRT and post-wildfire management. My fourth chapter took a broader look at the variables that influence perceptions of landscape recovery across different wildfires. Twenty-five fires that occurred in 2011 or 2012 in WA, OR, MT, and ID were selected to represent a range of fire behavior characteristics and landscape impacts. Then, residents who live near each of the 25 fires were randomly selected to receive survey questionnaires which asked about multiple facets of their experiences with the fire, the perceived social impacts from the fire, and specifically how the landscape had changed/recovered since the fire. Results showed that, overall, perceptions of landscape recovery no more than two years after the fire were positive. Regression analysis suggested that perceptions of recovery can be explained fairly well with several key variables. More negative evaluations of recovery were related to negative impacts to people's attachment to the landscape, negative perceptions of erosion problems, and longer lasting fires. More positive evaluations of recovery were related to more positive beliefs about the beneficial role of fire in terms of landscape health. Hierarchical Linear Modelling (HLM) analysis showed that these relationships were mostly consistent across fires, though there was some variability in the relationships between perceptions of landscape recovery and the variables that measured perceptions of erosion and beliefs about the ecological role of fire. These findings are discussed in terms of the scope of the study as well as their management implications. My fifth and concluding chapter summarized the main findings from each chapter and integrated them into a larger social-ecological context. Key limitations, considerations related to the validity and reliability of my research, and future research needs are discussed. My dissertation furthers the conceptual and empirical understanding of how people perceive landscape changes from natural disturbances and how managers can include these social dimensions into future planning and implementation efforts. Title: Understanding Public Perceptions of Post-Wildfire Landscape Recovery Author: Kooistra, Chad Forest disturbances, such as wildfires, pine beetle outbreaks, and floods are important features of many landscapes and ecosystems. Many disturbances are increasing in size, frequency, and intensity due to changing climates and land management decisions. The changing ecological and aesthetic conditions following a disturbance can lead to negative short- and long-term social impacts. This dissertation research examines one aspect of the relationship between people and their environment in the context of forest disturbances and landscape changes. Specifically, it explores how people perceive a changing landscape after a forest disturbance, a trajectory referred to here as landscape recovery. After describing the larger context of forest disturbances in the introductory chapter, with a focus on wildfires, my second dissertation chapter developed a conceptual framework for understanding how people perceive post-disturbance landscape recovery. It examined the social factors that are most likely to influence those perceptions based on literature from various disciplines. These factors included visual cues and aesthetic preferences, landscape values and connections, and beliefs about the ecological role of disturbances. I described how the concepts and methodological approaches from mental models and social representations traditions help depict and explain how perceptions of landscape recovery can be studied in a way that explores the process shaping the perceptions. I explained how these perceptions likely exist along a spectrum from more simple perceptions focused on aesthetic judgments to more complex perceptions based more on ecological knowledge. I then proposed a research agenda to further investigate this framework, along with a summary of management considerations. The third chapter empirically explored the framework from the previous chapter by applying social representations theory (SRT) to qualitative research in Montana about how people perceive post-wildfire landscape recovery. I examined the mechanistic (i.e., anchoring and objectification) and structural (i.e., central core and peripheral elements) aspects of representations by integrating the factors proposed earlier as most influential in affecting perceptions of recovery. Interviews were conducted in 2014 with 30 residents who experienced the 2012 Dahl Fire, near Roundup, MT. Participants were purposively selected to represent a range of the factors described in Chapter 2. The main propositions from Chapter 2 were explored in the data collection and analysis steps. The core of all respondents' representations was centered on the concept of "Mother Nature." The factors identified in Chapter 2 further shaped representations uniquely across the two main groups of residents (rural lifestyle and working landscape residents) through the anchoring and objectification processes. People's representations about recovery were anchored in general beliefs about the past ecological and socio-cultural role of fire in the landscape as influenced by their past experiences and knowledge about ecological disturbances. Interpretations of different aspects of the landscape, including vegetation composition and key ecosystem functions, were filtered through people's values for the landscape and their specific beliefs about how the fire affected the landscape. This led to variation in specific notions of what constitutes a recovered landscape across the two main social groups there. These findings are discussed in the context of SRT and post-wildfire management. My fourth chapter took a broader look at the variables that influence perceptions of landscape recovery across different wildfires. Twenty-five fires that occurred in 2011 or 2012 in WA, OR, MT, and ID were selected to represent a range of fire behavior characteristics and landscape impacts. Then, residents who live near each of the 25 fires were randomly selected to receive survey questionnaires which asked about multiple facets of their experiences with the fire, the perceived social impacts from the fire, and specifically how the landscape had changed/recovered since the fire. Results showed that, overall, perceptions of landscape recovery no more than two years after the fire were positive. Regression analysis suggested that perceptions of recovery can be explained fairly well with several key variables. More negative evaluations of recovery were related to negative impacts to people's attachment to the landscape, negative perceptions of erosion problems, and longer lasting fires. More positive evaluations of recovery were related to more positive beliefs about the beneficial role of fire in terms of landscape health. Hierarchical Linear Modelling (HLM) analysis showed that these relationships were mostly consistent across fires, though there was some variability in the relationships between perceptions of landscape recovery and the variables that measured perceptions of erosion and beliefs about the ecological role of fire. These findings are discussed in terms of the scope of the study as well as their management implications. My fifth and concluding chapter summarized the main findings from each chapter and integrated them into a larger social-ecological context. Key limitations, considerations related to the validity and reliability of my research, and future research needs are discussed. My dissertation furthers the conceptual and empirical understanding of how people perceive landscape changes from natural disturbances and how managers can include these social dimensions into future planning and implementation efforts. Close