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• 1. [Article] Influence of Wetland Landscape Structure on Duck Nest Success at Malheur National Wildlife Refuge, Oregon

  The decline of waterfowl populations and their requisite wetland habitats remains a concern. Because migratory bird refuges are often artificial landscapes of actively managed wetlands, and wildlife populations ...

  Citation × Citation Citation Abstract Copy Title: Influence of Wetland Landscape Structure on Duck Nest Success at Malheur National Wildlife Refuge, Oregon Author: Craver, Daniel Robert Year: 2010 The decline of waterfowl populations and their requisite wetland habitats remains a concern. Because migratory bird refuges are often artificial landscapes of actively managed wetlands, and wildlife populations experience their greatest change during the breeding season, refuges should be designed to maximize breeding habitat. While past nest success studies have focused on at-nest variables, new approaches are needed to evaluate the effect of composition and configuration of plant communities at the landscape scale. This study aims to quantify landscape patterns within individual refuge management units to determine influence upon historical nesting success averages of ducks at Malheur National Wildlife Refuge in southeastern Oregon. The Mayfield estimate of nest success for 8 duck species yields a survival rate of 25% for the years 1987-1998 with a range of 0-74% across 48 management units. FRAGSTATS was used to calculate a suite of 9 landscape pattern metrics per unit at the class-level for each of 3 wetland habitat classes, and at the landscape-level using all habitat types. These 36 variables were tested for association with survival rate using Pearson R correlation. Results suggest fragmentation of dry meadow habitat; patch size, complexity, and extensiveness of wet meadow habitat; and diversity of habitats across the landscape positively influence duck nest success at the scale of the individual management unit. Title: Influence of Wetland Landscape Structure on Duck Nest Success at Malheur National Wildlife Refuge, Oregon Author: Craver, Daniel Robert Year: 2010 The decline of waterfowl populations and their requisite wetland habitats remains a concern. Because migratory bird refuges are often artificial landscapes of actively managed wetlands, and wildlife populations experience their greatest change during the breeding season, refuges should be designed to maximize breeding habitat. While past nest success studies have focused on at-nest variables, new approaches are needed to evaluate the effect of composition and configuration of plant communities at the landscape scale. This study aims to quantify landscape patterns within individual refuge management units to determine influence upon historical nesting success averages of ducks at Malheur National Wildlife Refuge in southeastern Oregon. The Mayfield estimate of nest success for 8 duck species yields a survival rate of 25% for the years 1987-1998 with a range of 0-74% across 48 management units. FRAGSTATS was used to calculate a suite of 9 landscape pattern metrics per unit at the class-level for each of 3 wetland habitat classes, and at the landscape-level using all habitat types. These 36 variables were tested for association with survival rate using Pearson R correlation. Results suggest fragmentation of dry meadow habitat; patch size, complexity, and extensiveness of wet meadow habitat; and diversity of habitats across the landscape positively influence duck nest success at the scale of the individual management unit. Close

• 2. [Article] Efficacy of Plastic Mesh Tubes in Reducing Herbivory Damage by the Invasive Nutria (Myocastor coypus) in an Urban Restoration Site

  The restoration of stream corridors is becoming an increasingly important component of urban landscape planning, and the high cost of these projects necessitates the need to understand and address potential ...

  Citation × Citation Citation Abstract Copy Title: Efficacy of Plastic Mesh Tubes in Reducing Herbivory Damage by the Invasive Nutria (Myocastor coypus) in an Urban Restoration Site Author: Sheffels, Trevor R., Sytsma, Mark D., Carter, Jacoby, Taylor, Jimmy D. Year: 2014 The restoration of stream corridors is becoming an increasingly important component of urban landscape planning, and the high cost of these projects necessitates the need to understand and address potential ecological obstacles to project success. The nutria (Myocastor coypus) is an invasive, semi-aquatic rodent native to South America that causes detrimental ecological impacts in riparian and wetland habitats throughout its introduced range, and techniques are needed to reduce nutria herbivory damage to urban stream restoration projects. We assessed the efficacy of standard Vexar® plastic mesh tubes in reducing nutria herbivory damage to newly established woody plants. The study was conducted in winter-spring 2009 at Delta Ponds, a 60-ha urban waterway in Eugene, Oregon. Woody plants protected by Vexar® tubes demonstrated 100% survival over the 3-month initial establishment period, while only 17% of unprotected plantings survived. Nutria demonstrated a preference for black cottonwood(Populus balsamifera ssp trichocarpa) over red osier dogwood (Cornus sericea) and willow (Salix spp). Camera surveillance showed that nutria were more active in unprotected rather than protected treatments. Our results suggest that Vexar® plastic mesh tubing can be an effective short-term herbivory mitigation tool when habitat use by nutria is low. Additionally, planting functionally equivalent woody plant species that are less preferred by nutria, and other herbivores, may be another method for reducing herbivory and improving revegetation success. This study highlights the need to address potential wildlife damage conflicts in the planning process for stream restoration in urban landscapes. Title: Efficacy of Plastic Mesh Tubes in Reducing Herbivory Damage by the Invasive Nutria (Myocastor coypus) in an Urban Restoration Site Author: Sheffels, Trevor R., Sytsma, Mark D., Carter, Jacoby, Taylor, Jimmy D. Year: 2014 The restoration of stream corridors is becoming an increasingly important component of urban landscape planning, and the high cost of these projects necessitates the need to understand and address potential ecological obstacles to project success. The nutria (Myocastor coypus) is an invasive, semi-aquatic rodent native to South America that causes detrimental ecological impacts in riparian and wetland habitats throughout its introduced range, and techniques are needed to reduce nutria herbivory damage to urban stream restoration projects. We assessed the efficacy of standard Vexar® plastic mesh tubes in reducing nutria herbivory damage to newly established woody plants. The study was conducted in winter-spring 2009 at Delta Ponds, a 60-ha urban waterway in Eugene, Oregon. Woody plants protected by Vexar® tubes demonstrated 100% survival over the 3-month initial establishment period, while only 17% of unprotected plantings survived. Nutria demonstrated a preference for black cottonwood(Populus balsamifera ssp trichocarpa) over red osier dogwood (Cornus sericea) and willow (Salix spp). Camera surveillance showed that nutria were more active in unprotected rather than protected treatments. Our results suggest that Vexar® plastic mesh tubing can be an effective short-term herbivory mitigation tool when habitat use by nutria is low. Additionally, planting functionally equivalent woody plant species that are less preferred by nutria, and other herbivores, may be another method for reducing herbivory and improving revegetation success. This study highlights the need to address potential wildlife damage conflicts in the planning process for stream restoration in urban landscapes. Close

• 3. [Article] Ecosystem Recovery in Estuarine Wetlands of the Columbia River Estuary

  In the restoration of tidal wetland ecosystems, potential drivers of plant community development range from biotic controls (e.g. plant competition, seed dispersal) to abiotic controls (e.g. tidal flooding, ...

  Citation × Citation Citation Abstract Copy Title: Ecosystem Recovery in Estuarine Wetlands of the Columbia River Estuary Author: Kidd, Sarah Ann Year: 2017 In the restoration of tidal wetland ecosystems, potential drivers of plant community development range from biotic controls (e.g. plant competition, seed dispersal) to abiotic controls (e.g. tidal flooding, salinity levels). How these controls influence the success of tidal wetland restoration are only partly understood, but have important implications for wetland habitat recovery. Specifically, the extent to which the existing native and non-native seed banks in tidally reconnected wetlands interact with these controls is not clear, yet the potential success of passive restoration methods depends upon this understanding. For a 54-year chronosequence of eleven tidal wetland restoration sites in the Lower Columbia River of western Oregon, USA, it was hypothesized that native plant species and soil properties would show trends approaching reference levels within 3 to 20 years post-restoration and that lower elevation wetland areas within restored sites would exhibit a greater native species abundance and similarity to reference sites, compared with restored high elevation wetland areas. Results indicated that plant species richness, soil organic matter, bulk density, pH, and salinity conditions among the restoration sites reached reference wetland ranges within 3-6 years post-tidal reconnection. The mid-low marsh elevation zones (2.5 m) remained dominated by non-native species Phalaris arundinacea and Juncus effusus subsp. effusus. To investigate the mechanisms driving these non-native plant invasions, it was hypothesized that native and non-native wetland plant community distributions would be reflective both of their abundance in the seed bank and of their germination tolerance to wetland tidal flooding and salinity conditions. Using a factorial study design of three tidal conditions by three salinity levels, these hypotheses were tested in the greenhouse. Overall, non-native seeds were found to significantly outnumber native seeds in both seed banks. In the greenhouse, P. arundinacea and J. effusus were found to germinate more readily out of the seed bank under freshwater high-marsh flooding (1 hour a day) treatments as compared to oligohaline (3 ppt) mid-low marsh flooding (3-6 hours twice a day) treatments and to brackish salinity (10 ppt) treatments. Dominant native wetland species, Carex lyngbyei and Schoenoplectus lacustris, germination were not found to vary significantly among the treatments (p > 0.10). These results indicate that the salinity and flooding gradients within these restored marshes suppress germination of the non-native species in the low-mid marsh but not in the high marsh, where they are likely able to outcompete the native species due to their dominance in the seed bank. The implications of these results for passive tidal wetland restoration efforts are that both seed bank composition and species-specific tolerances to restored tidal flooding and salinity gradients are key mechanisms driving native and non-native plant community development and resilience. Title: Ecosystem Recovery in Estuarine Wetlands of the Columbia River Estuary Author: Kidd, Sarah Ann Year: 2017 In the restoration of tidal wetland ecosystems, potential drivers of plant community development range from biotic controls (e.g. plant competition, seed dispersal) to abiotic controls (e.g. tidal flooding, salinity levels). How these controls influence the success of tidal wetland restoration are only partly understood, but have important implications for wetland habitat recovery. Specifically, the extent to which the existing native and non-native seed banks in tidally reconnected wetlands interact with these controls is not clear, yet the potential success of passive restoration methods depends upon this understanding. For a 54-year chronosequence of eleven tidal wetland restoration sites in the Lower Columbia River of western Oregon, USA, it was hypothesized that native plant species and soil properties would show trends approaching reference levels within 3 to 20 years post-restoration and that lower elevation wetland areas within restored sites would exhibit a greater native species abundance and similarity to reference sites, compared with restored high elevation wetland areas. Results indicated that plant species richness, soil organic matter, bulk density, pH, and salinity conditions among the restoration sites reached reference wetland ranges within 3-6 years post-tidal reconnection. The mid-low marsh elevation zones (2.5 m) remained dominated by non-native species Phalaris arundinacea and Juncus effusus subsp. effusus. To investigate the mechanisms driving these non-native plant invasions, it was hypothesized that native and non-native wetland plant community distributions would be reflective both of their abundance in the seed bank and of their germination tolerance to wetland tidal flooding and salinity conditions. Using a factorial study design of three tidal conditions by three salinity levels, these hypotheses were tested in the greenhouse. Overall, non-native seeds were found to significantly outnumber native seeds in both seed banks. In the greenhouse, P. arundinacea and J. effusus were found to germinate more readily out of the seed bank under freshwater high-marsh flooding (1 hour a day) treatments as compared to oligohaline (3 ppt) mid-low marsh flooding (3-6 hours twice a day) treatments and to brackish salinity (10 ppt) treatments. Dominant native wetland species, Carex lyngbyei and Schoenoplectus lacustris, germination were not found to vary significantly among the treatments (p > 0.10). These results indicate that the salinity and flooding gradients within these restored marshes suppress germination of the non-native species in the low-mid marsh but not in the high marsh, where they are likely able to outcompete the native species due to their dominance in the seed bank. The implications of these results for passive tidal wetland restoration efforts are that both seed bank composition and species-specific tolerances to restored tidal flooding and salinity gradients are key mechanisms driving native and non-native plant community development and resilience. Close

• 4. [Article] Report on Nutria Management and Research in the Pacific Northwest

  The nutria (Myocastor coypus) is a large semi-aquatic mammal native to South America that has been introduced to numerous countries around the world, primarily for fur farming. Nutria were introduced in ...

  Citation × Citation Citation Abstract Copy Title: Report on Nutria Management and Research in the Pacific Northwest Author: Sheffels, Trevor Robert, Sytsma, Mark Year: 2007 The nutria (Myocastor coypus) is a large semi-aquatic mammal native to South America that has been introduced to numerous countries around the world, primarily for fur farming. Nutria were introduced in Oregon and Washington in the 1930s, and feral populations were documented in 1943. Populations are known to be expanding in both Oregon and Washington, and regional nutria damage and nuisance complaints have increased in recent years. Most of the extensive damage caused by nutria is a direct result of feeding and burrowing, but nutria are also capable of transporting parasites and pathogens transmittable to humans, livestock, and pets. Although several past regional and local nutria research and management projects have been identified, there is a shortage of nutria information from the Pacific Northwest considering that the species has been present in the region for approximately seventy years. The Center for Lakes and Reservoirs (CLR) at Portland State University (PSU), in partnership with several local, state, and federal agencies, has taken the lead in addressing the regional nutria problem. Activities completed to date include a regional nutria management workshop, the ongoing development of a regional nutria distribution/density map, and a research project to analyze the impact of nutria herbivory on regional riparian wetland habitat restoration projects. In addition, the CLR at PSU is participating in the development of the national Aquatic Nuisance Species Task Force nutria management plan. This initial assessment of the current nutria situation in the Pacific Northwest conducted by the CLR at PSU has revealed that regional nutria problems are more extensive than previously realized. Nutria sightings have now been confirmed from the Canadian border to near the southern border of Oregon, confirming a larger range than was previously known. It was also found that the main nutria issues in the Pacific Northwest differ from the main nutria issues in Louisiana and Maryland. For example, the most significant category of regional nutria damage appears to be the destruction of water control structures and associated erosion caused by nutria burrowing, as opposed to nutria herbivory damage in Louisiana and Maryland. Another unique situation in the Pacific Northwest is the high density of nutria populations in urban areas, increasing the potential for conflicts between nutria and humans. Nutria attacks have been reported in isolated cases, and nutria are rodents that carry a variety of transmittable parasites and pathogens. It has also been confirmed that significant regional nutria herbivory damage does occur at some locations. Fortunately, it has become evident through the course of this assessment that a strong regional interest to address the nutria problem exists. A wide variety of agencies and organizations across the region are being negatively impacted by nutria, and these entities are ready to move forward to develop a feasible solution. To date, small-scale nutria management and eradication efforts have been somewhat effective temporarily, but a more permanent solution requires that the situation be addressed on a much larger scale. Due to the long period of time since the initial nutria introduction, the extent of current regional nutria populations, and the changing climate patterns, a long-term effort will likely be required to effectively address the regional nutria issue. The most immediate management need is to develop an official regional nutria management plan with the focus of greatly reducing the amount of damage being caused by this invasive rodent and preventing further population growth and expansion. The effectiveness of initial management efforts will shed light on how to adapt management strategies in the future and whether or not regional eradication is a feasible option. Continued nutria research and the development of coordinated management efforts at the regional scale are vital in order to bring the current regional nutria problem under control. The CLR at PSU has developed initial recommendations to help guide the process of determining how to most effectively manage nutria in the Pacific Northwest. First and foremost, funding sources for continued work on the regional nutria problem must be found. Once funding is secured, the development of an official nutria regional management plan is crucial. Priorities connected with the management plan would include creating an early detection rapid response plan, identifying best management practices, initiating a pilot eradication program, and identifying priority research needs. Potential research studies include a long-term pilot eradication project at the watershed level, relationships between climate change and regional nutria dispersal, and the dynamics of nutria-muskrat interactions. It is also evident that further coordination between local, state, and federal agencies is necessary to delegate responsibilities and keep all parties updated. The creation of a central regional database and appropriate agency protocols could be used to collect information about nutria damage and associated economic impacts. Current laws and regulations pertaining to nutria should be enforced and possibly updated so that Oregon and Washington laws are uniform. Finally, it is important to inform the public about current nutria issues and utilize resources the general public can potentially provide. Title: Report on Nutria Management and Research in the Pacific Northwest Author: Sheffels, Trevor Robert, Sytsma, Mark Year: 2007 The nutria (Myocastor coypus) is a large semi-aquatic mammal native to South America that has been introduced to numerous countries around the world, primarily for fur farming. Nutria were introduced in Oregon and Washington in the 1930s, and feral populations were documented in 1943. Populations are known to be expanding in both Oregon and Washington, and regional nutria damage and nuisance complaints have increased in recent years. Most of the extensive damage caused by nutria is a direct result of feeding and burrowing, but nutria are also capable of transporting parasites and pathogens transmittable to humans, livestock, and pets. Although several past regional and local nutria research and management projects have been identified, there is a shortage of nutria information from the Pacific Northwest considering that the species has been present in the region for approximately seventy years. The Center for Lakes and Reservoirs (CLR) at Portland State University (PSU), in partnership with several local, state, and federal agencies, has taken the lead in addressing the regional nutria problem. Activities completed to date include a regional nutria management workshop, the ongoing development of a regional nutria distribution/density map, and a research project to analyze the impact of nutria herbivory on regional riparian wetland habitat restoration projects. In addition, the CLR at PSU is participating in the development of the national Aquatic Nuisance Species Task Force nutria management plan. This initial assessment of the current nutria situation in the Pacific Northwest conducted by the CLR at PSU has revealed that regional nutria problems are more extensive than previously realized. Nutria sightings have now been confirmed from the Canadian border to near the southern border of Oregon, confirming a larger range than was previously known. It was also found that the main nutria issues in the Pacific Northwest differ from the main nutria issues in Louisiana and Maryland. For example, the most significant category of regional nutria damage appears to be the destruction of water control structures and associated erosion caused by nutria burrowing, as opposed to nutria herbivory damage in Louisiana and Maryland. Another unique situation in the Pacific Northwest is the high density of nutria populations in urban areas, increasing the potential for conflicts between nutria and humans. Nutria attacks have been reported in isolated cases, and nutria are rodents that carry a variety of transmittable parasites and pathogens. It has also been confirmed that significant regional nutria herbivory damage does occur at some locations. Fortunately, it has become evident through the course of this assessment that a strong regional interest to address the nutria problem exists. A wide variety of agencies and organizations across the region are being negatively impacted by nutria, and these entities are ready to move forward to develop a feasible solution. To date, small-scale nutria management and eradication efforts have been somewhat effective temporarily, but a more permanent solution requires that the situation be addressed on a much larger scale. Due to the long period of time since the initial nutria introduction, the extent of current regional nutria populations, and the changing climate patterns, a long-term effort will likely be required to effectively address the regional nutria issue. The most immediate management need is to develop an official regional nutria management plan with the focus of greatly reducing the amount of damage being caused by this invasive rodent and preventing further population growth and expansion. The effectiveness of initial management efforts will shed light on how to adapt management strategies in the future and whether or not regional eradication is a feasible option. Continued nutria research and the development of coordinated management efforts at the regional scale are vital in order to bring the current regional nutria problem under control. The CLR at PSU has developed initial recommendations to help guide the process of determining how to most effectively manage nutria in the Pacific Northwest. First and foremost, funding sources for continued work on the regional nutria problem must be found. Once funding is secured, the development of an official nutria regional management plan is crucial. Priorities connected with the management plan would include creating an early detection rapid response plan, identifying best management practices, initiating a pilot eradication program, and identifying priority research needs. Potential research studies include a long-term pilot eradication project at the watershed level, relationships between climate change and regional nutria dispersal, and the dynamics of nutria-muskrat interactions. It is also evident that further coordination between local, state, and federal agencies is necessary to delegate responsibilities and keep all parties updated. The creation of a central regional database and appropriate agency protocols could be used to collect information about nutria damage and associated economic impacts. Current laws and regulations pertaining to nutria should be enforced and possibly updated so that Oregon and Washington laws are uniform. Finally, it is important to inform the public about current nutria issues and utilize resources the general public can potentially provide. Close

• 5. [Article] Status of Nutria (Myocastor coypus) Populations in the Pacific Northwest and Development of Associated Control and Management Strategies, with an Emphasis on Metropolitan Habitats

  The nutria (Myocastor coypus) is a semi-aquatic rodent native to South America that was introduced to the Pacific Northwest, USA, in the 1930s. Primary damage categories from this invasive species include ...

  Citation × Citation Citation Abstract Copy Title: Status of Nutria (Myocastor coypus) Populations in the Pacific Northwest and Development of Associated Control and Management Strategies, with an Emphasis on Metropolitan Habitats Author: Sheffels, Trevor Robert Year: 2013 The nutria (Myocastor coypus) is a semi-aquatic rodent native to South America that was introduced to the Pacific Northwest, USA, in the 1930s. Primary damage categories from this invasive species include burrowing and herbivory, resulting in habitat degradation. Nutria have become well-established in metropolitan habitats, and anecdotal information suggests the problem has increased in recent years. However, little regional research on the species has been conducted. The scope of this research, which emphasizes metropolitan habitats, includes three primary foci in relation to nutria populations in the Pacific Northwest: modeling habitat suitability, assessing activity and movement patterns, and identifying and managing negative impacts. Large-scale management of any invasive species requires understanding of the current and potential future population distribution. Cold temperatures have been assumed to be a limiting factor for the geographic distribution of nutria populations, but this assumption had not been explicitly tested. A mechanistic habitat suitability model based on winter temperatures performed well in predicting nutria distribution in the Pacific Northwest and nationally. Regional results suggest nutria currently occupy most accessible suitable habitat. However, coupling the model with future climate change data suggests a much larger suitable habitat zone regionally and nationally in the near future. Management of an invasive species on a local scale requires region-specific information about behavior patterns. Radio-telemetry tracking of local nutria populations in metropolitan habitats suggested higher diurnal activity levels than reported elsewhere. Activity areas were also on the lower end of reported nutria home ranges, suggesting the studied metropolitan wetland sites represent core habitat for nutria in the region. Comparison of two transmitter attachment methods, a neck collar and a tail mount, did not identify a clearly superior attachment method for short-term nutria behavior studies. The presence of nutria in metropolitan habitats in the Pacific Northwest necessitates the need to expand the limited management techniques available for these habitats. Standard Vexar® plastic mesh tubes very effectively mitigated nutria herbivory damage to woody vegetation live stakes planted in a metropolitan habitat restoration site. A recently developed nutria multiple-capture cage trap captured larger nutria and reduced non-target captures compared to a standard cage trap. The design of the multiple-capture trap, however, prevented multiple-capture events because small nutria escaped the trap. This research contributes substantially to previously limited information about nutria in the Pacific Northwest and resulted in several new findings. Climate change modeling provides the first evidence that nutria ranges could expand in the near future. Evaluation of new radio-telemetry methods will benefit future behavior studies. The assessment of new damage prevention tools provides more options for the management of nutria in urban habitats. Management recommendations include creating regional nutria management plans, identifying and targeting priority monitoring regions, finding key stakeholders, focusing on public education, and initiating a pilot control program. Recommendations for research include evaluating effects on native fauna, conducting disease surveys, assessing the extent of damage, continuing habitat suitability analysis, and developing population indices. Title: Status of Nutria (Myocastor coypus) Populations in the Pacific Northwest and Development of Associated Control and Management Strategies, with an Emphasis on Metropolitan Habitats Author: Sheffels, Trevor Robert Year: 2013 The nutria (Myocastor coypus) is a semi-aquatic rodent native to South America that was introduced to the Pacific Northwest, USA, in the 1930s. Primary damage categories from this invasive species include burrowing and herbivory, resulting in habitat degradation. Nutria have become well-established in metropolitan habitats, and anecdotal information suggests the problem has increased in recent years. However, little regional research on the species has been conducted. The scope of this research, which emphasizes metropolitan habitats, includes three primary foci in relation to nutria populations in the Pacific Northwest: modeling habitat suitability, assessing activity and movement patterns, and identifying and managing negative impacts. Large-scale management of any invasive species requires understanding of the current and potential future population distribution. Cold temperatures have been assumed to be a limiting factor for the geographic distribution of nutria populations, but this assumption had not been explicitly tested. A mechanistic habitat suitability model based on winter temperatures performed well in predicting nutria distribution in the Pacific Northwest and nationally. Regional results suggest nutria currently occupy most accessible suitable habitat. However, coupling the model with future climate change data suggests a much larger suitable habitat zone regionally and nationally in the near future. Management of an invasive species on a local scale requires region-specific information about behavior patterns. Radio-telemetry tracking of local nutria populations in metropolitan habitats suggested higher diurnal activity levels than reported elsewhere. Activity areas were also on the lower end of reported nutria home ranges, suggesting the studied metropolitan wetland sites represent core habitat for nutria in the region. Comparison of two transmitter attachment methods, a neck collar and a tail mount, did not identify a clearly superior attachment method for short-term nutria behavior studies. The presence of nutria in metropolitan habitats in the Pacific Northwest necessitates the need to expand the limited management techniques available for these habitats. Standard Vexar® plastic mesh tubes very effectively mitigated nutria herbivory damage to woody vegetation live stakes planted in a metropolitan habitat restoration site. A recently developed nutria multiple-capture cage trap captured larger nutria and reduced non-target captures compared to a standard cage trap. The design of the multiple-capture trap, however, prevented multiple-capture events because small nutria escaped the trap. This research contributes substantially to previously limited information about nutria in the Pacific Northwest and resulted in several new findings. Climate change modeling provides the first evidence that nutria ranges could expand in the near future. Evaluation of new radio-telemetry methods will benefit future behavior studies. The assessment of new damage prevention tools provides more options for the management of nutria in urban habitats. Management recommendations include creating regional nutria management plans, identifying and targeting priority monitoring regions, finding key stakeholders, focusing on public education, and initiating a pilot control program. Recommendations for research include evaluating effects on native fauna, conducting disease surveys, assessing the extent of damage, continuing habitat suitability analysis, and developing population indices. Close

• 6. [Article] Koll Center Wetlands Natural Resources Maintenance Management Plan

  The intention of this plan is to provide a vision and guidelines for maintaining and improving the ecological health of Koll Center Wetlands in the short and long term. Although the plan will change over ...

  Citation × Citation Citation Abstract Copy Title: Koll Center Wetlands Natural Resources Maintenance Management Plan Author: Clayton, Meredith Year: 2006 The intention of this plan is to provide a vision and guidelines for maintaining and improving the ecological health of Koll Center Wetlands in the short and long term. Although the plan will change over time, the goal is to quantify natural resource needs spatially, temporally, and economically. Koll Center Wetlands is part of the Greenway/Fanno Creek/Koll Center Wetlands Park complex. The nearly 13 acre park is dominated by aquatic habitats that attract a wide variety of wildlife, particularly birds. The park grounds are not easily traversed and experience limited human use, but there are many viewpoints from which the park is easily and commonly observed by visitors. The park serves as valuable habitat for both local and migratory wildlife as it connects with the many other terrestrial and aquatic habitats of the park complex, forming a large wildlife corridor in an otherwise urban setting. The aquatic habitats respond to fluctuating water levels, creating seasonally diverse habitat conditions that support a variety of birds, mammals, and reptiles. A mixed forest grows on the southern slope of the park, housing a heron rookery and many well-established oaks and conifers. A weir located just past the south border of the property enables the wetlands to provide the services of storm detention and water filtration for runoff from the surrounding business park. Runoff from parking lots and landscaped areas can contain contaminants and nutrients capable of jeopardizing stream health. Settling and filtration of these compounds occurs as water travels north to south in the wetland, making the water that ultimately reaches Fanno Creek cleaner than it began. Since Koll Center Wetlands is located within a highly urbanized area, direct and indirect impacts to the natural areas from the surrounding region are considered in the maintenance management plan (MMP) for the park and its individual habitat units. These include, but are not limited to, direct human impacts, invasive plants and animals, and ongoing natural processes in plant communities. Title: Koll Center Wetlands Natural Resources Maintenance Management Plan Author: Clayton, Meredith Year: 2006 The intention of this plan is to provide a vision and guidelines for maintaining and improving the ecological health of Koll Center Wetlands in the short and long term. Although the plan will change over time, the goal is to quantify natural resource needs spatially, temporally, and economically. Koll Center Wetlands is part of the Greenway/Fanno Creek/Koll Center Wetlands Park complex. The nearly 13 acre park is dominated by aquatic habitats that attract a wide variety of wildlife, particularly birds. The park grounds are not easily traversed and experience limited human use, but there are many viewpoints from which the park is easily and commonly observed by visitors. The park serves as valuable habitat for both local and migratory wildlife as it connects with the many other terrestrial and aquatic habitats of the park complex, forming a large wildlife corridor in an otherwise urban setting. The aquatic habitats respond to fluctuating water levels, creating seasonally diverse habitat conditions that support a variety of birds, mammals, and reptiles. A mixed forest grows on the southern slope of the park, housing a heron rookery and many well-established oaks and conifers. A weir located just past the south border of the property enables the wetlands to provide the services of storm detention and water filtration for runoff from the surrounding business park. Runoff from parking lots and landscaped areas can contain contaminants and nutrients capable of jeopardizing stream health. Settling and filtration of these compounds occurs as water travels north to south in the wetland, making the water that ultimately reaches Fanno Creek cleaner than it began. Since Koll Center Wetlands is located within a highly urbanized area, direct and indirect impacts to the natural areas from the surrounding region are considered in the maintenance management plan (MMP) for the park and its individual habitat units. These include, but are not limited to, direct human impacts, invasive plants and animals, and ongoing natural processes in plant communities. Close

• 7. [Article] Assessing Habitat Requirements of Pond-Breeding Amphibians in a Highly Urbanized Landscape:Implications for Management

  Management of urban aquatic habitats for native wildlife, such as amphibians, is an important contemporary goal for many municipalities. However, our understanding of how local and landscape characteristics ...

  Citation × Citation Citation Abstract Copy Title: Assessing Habitat Requirements of Pond-Breeding Amphibians in a Highly Urbanized Landscape:Implications for Management Author: Guderyahn, Laura B., Smithers, Ashley P., Mims, Meryl C. Year: 2016 Management of urban aquatic habitats for native wildlife, such as amphibians, is an important contemporary goal for many municipalities. However, our understanding of how local and landscape characteristics of urban aquatic habitat promote or inhibit amphibian occupancy and recruitment is limited. In this study, we examined amphibian community composition and occurrence patterns in ponds, wetlands, and swales of Gresham, Oregon. We collected occurrence data for five native amphibians: northwestern salamander (Ambystoma gracile), long-toed salamander (A. macrodactylum), Pacific chorus frog (Pseudacris regilla), northern red-legged frog (Rana aurora aurora), and rough-skinned newt (Taricha granulosa) as well as one non-native amphibian, the American bullfrog (Lithobates catesbeianus). One hundred sites were surveyed from 2007 to 2013. Local and landscape attributes were characterized for each site, and potential drivers of species occupancy were evaluated using a combination of multivariate approaches and generalized linear models. In general, percent impervious surface and distance to nearest forest patch, both associated with urbanization, were negatively correlated with site occupancy for all species. Non-native vegetation was also negatively associated with occupancy of three species (long-toed salamanders, Pacific chorus frogs, and northern red-legged frogs). In contrast, occupancy was positively correlated with pond depth and hydroperiod length for all species. We found evidence of two distinct groups of co-occurring amphibian species driven by habitat depth and hydroperiod. Finally, we report results of threshold analyses that examined species-specific habitat associations. This study describes urban habitat associations of a native amphibian community, identifies factors with positive, negative or mixed relationships with amphibian species, and is an important step in informing the management of urban aquatic habitat to promote persistence of native amphibians. Title: Assessing Habitat Requirements of Pond-Breeding Amphibians in a Highly Urbanized Landscape:Implications for Management Author: Guderyahn, Laura B., Smithers, Ashley P., Mims, Meryl C. Year: 2016 Management of urban aquatic habitats for native wildlife, such as amphibians, is an important contemporary goal for many municipalities. However, our understanding of how local and landscape characteristics of urban aquatic habitat promote or inhibit amphibian occupancy and recruitment is limited. In this study, we examined amphibian community composition and occurrence patterns in ponds, wetlands, and swales of Gresham, Oregon. We collected occurrence data for five native amphibians: northwestern salamander (Ambystoma gracile), long-toed salamander (A. macrodactylum), Pacific chorus frog (Pseudacris regilla), northern red-legged frog (Rana aurora aurora), and rough-skinned newt (Taricha granulosa) as well as one non-native amphibian, the American bullfrog (Lithobates catesbeianus). One hundred sites were surveyed from 2007 to 2013. Local and landscape attributes were characterized for each site, and potential drivers of species occupancy were evaluated using a combination of multivariate approaches and generalized linear models. In general, percent impervious surface and distance to nearest forest patch, both associated with urbanization, were negatively correlated with site occupancy for all species. Non-native vegetation was also negatively associated with occupancy of three species (long-toed salamanders, Pacific chorus frogs, and northern red-legged frogs). In contrast, occupancy was positively correlated with pond depth and hydroperiod length for all species. We found evidence of two distinct groups of co-occurring amphibian species driven by habitat depth and hydroperiod. Finally, we report results of threshold analyses that examined species-specific habitat associations. This study describes urban habitat associations of a native amphibian community, identifies factors with positive, negative or mixed relationships with amphibian species, and is an important step in informing the management of urban aquatic habitat to promote persistence of native amphibians. Close

• 8. [Article] Wet Meadow Plant Associations, Malheur National Wildlife Refuge, Harney County, Oregon

  In July 2012, we sampled 131 plots in wet meadow habitat at the southern end of the Malheur National Wildlife Refuge. Analysis of the data identified eleven different plant associations: Alopecurus pratensis, ...

  Citation × Citation Citation Abstract Copy Title: Wet Meadow Plant Associations, Malheur National Wildlife Refuge, Harney County, Oregon Author: Christy, John A. Year: 2013 In July 2012, we sampled 131 plots in wet meadow habitat at the southern end of the Malheur National Wildlife Refuge. Analysis of the data identified eleven different plant associations: Alopecurus pratensis, Carex aquatilis var. aquatilis, Carex nebrascensis, Carex pellita, Carex praegracilis, Carex sheldonii, Distichlis spicata, Juncus balticus, Leymus triticoides, Phalaris arundinacea, and Sparganium eurycarpum. Plant associations spanned a wetland gradient from seasonally moist to seasonally or perennially flooded, but surface water had left most stands at time of sampling. Mean Wetland Indicator Status scores help to place the plant associations within gradients in soil moisture and alkalinity. The Alopecurus pratensis and Phalaris arundinacea associations are dominated by exotic, invasive species and appear to be outcompeting native plant associations. Phases of the Carex praegracilis association appear to be replaced by the Alopecurus pratensis association, while the Carex pellita, Juncus balticus, and Leymus triticoides associations may be replaced by the Phalaris arundinacea association. The Carex aquatilis and Sparganium eurycarpum associations were undersampled and provide only an estimate of composition. Most associations are consistent with what has been included in the National Vegetation Classification. Title: Wet Meadow Plant Associations, Malheur National Wildlife Refuge, Harney County, Oregon Author: Christy, John A. Year: 2013 In July 2012, we sampled 131 plots in wet meadow habitat at the southern end of the Malheur National Wildlife Refuge. Analysis of the data identified eleven different plant associations: Alopecurus pratensis, Carex aquatilis var. aquatilis, Carex nebrascensis, Carex pellita, Carex praegracilis, Carex sheldonii, Distichlis spicata, Juncus balticus, Leymus triticoides, Phalaris arundinacea, and Sparganium eurycarpum. Plant associations spanned a wetland gradient from seasonally moist to seasonally or perennially flooded, but surface water had left most stands at time of sampling. Mean Wetland Indicator Status scores help to place the plant associations within gradients in soil moisture and alkalinity. The Alopecurus pratensis and Phalaris arundinacea associations are dominated by exotic, invasive species and appear to be outcompeting native plant associations. Phases of the Carex praegracilis association appear to be replaced by the Alopecurus pratensis association, while the Carex pellita, Juncus balticus, and Leymus triticoides associations may be replaced by the Phalaris arundinacea association. The Carex aquatilis and Sparganium eurycarpum associations were undersampled and provide only an estimate of composition. Most associations are consistent with what has been included in the National Vegetation Classification. Close

• 9. [Article] Wet Meadow Plant Associations, Double O Unit, Malheur National Wildlife Refuge, Harney County, Oregon

  This report summarizes vegetation data collected in July 2015 in wet meadow and marshy habitats on the Double O Unit of Malheur National Wildlife Refuge (MNWR). Because vegetation sampled at the Double ...

  Citation × Citation Citation Abstract Copy Title: Wet Meadow Plant Associations, Double O Unit, Malheur National Wildlife Refuge, Harney County, Oregon Author: Christy, John A. Year: 2016 This report summarizes vegetation data collected in July 2015 in wet meadow and marshy habitats on the Double O Unit of Malheur National Wildlife Refuge (MNWR). Because vegetation sampled at the Double O was wetter and more alkaline than wet meadows sampled at the south end of the refuge in 2012 and 2013 (Christy 2014), data from the Double O Unit were analyzed and summarized separately. A total of 83 plots were sampled in 2015, and analysis of the data identified 14 plant associations: Alopecurus aequalis - Juncus balticus, Alopecurus pratensis - Potentilla anserina, Carex praegracilis - Juncus balticus, Cicuta douglasii - Carex nebrascensis, Distichlis spicata - Amphiscirpus nevadensis, Distichlis spicata - Nitrophila occidentalis, Eleocharis palustris - Juncus balticus, Eleocharis rostellata, Juncus balticus - Glaux maritima, Hippuris vulgaris - Triglochin maritima, Leymus triticoides - Juncus balticus, Schoenoplectus americanus, Spartina gracilis, and Triglochin maritima. Plant associations spanned a wetland gradient from seasonally moist to seasonally or perennially flooded, but surface water had left most stands at time of sampling. Mean Wetland Indicator Status scores and species composition help to place the plant associations within gradients in soil moisture and alkalinity. Seven of the 14 plant associations are listed in the International Vegetation Classification, and the remaining types are provisional Title: Wet Meadow Plant Associations, Double O Unit, Malheur National Wildlife Refuge, Harney County, Oregon Author: Christy, John A. Year: 2016 This report summarizes vegetation data collected in July 2015 in wet meadow and marshy habitats on the Double O Unit of Malheur National Wildlife Refuge (MNWR). Because vegetation sampled at the Double O was wetter and more alkaline than wet meadows sampled at the south end of the refuge in 2012 and 2013 (Christy 2014), data from the Double O Unit were analyzed and summarized separately. A total of 83 plots were sampled in 2015, and analysis of the data identified 14 plant associations: Alopecurus aequalis - Juncus balticus, Alopecurus pratensis - Potentilla anserina, Carex praegracilis - Juncus balticus, Cicuta douglasii - Carex nebrascensis, Distichlis spicata - Amphiscirpus nevadensis, Distichlis spicata - Nitrophila occidentalis, Eleocharis palustris - Juncus balticus, Eleocharis rostellata, Juncus balticus - Glaux maritima, Hippuris vulgaris - Triglochin maritima, Leymus triticoides - Juncus balticus, Schoenoplectus americanus, Spartina gracilis, and Triglochin maritima. Plant associations spanned a wetland gradient from seasonally moist to seasonally or perennially flooded, but surface water had left most stands at time of sampling. Mean Wetland Indicator Status scores and species composition help to place the plant associations within gradients in soil moisture and alkalinity. Seven of the 14 plant associations are listed in the International Vegetation Classification, and the remaining types are provisional Close

• 10. [Article] Modeling Historic Columbia River Flood Impacts

  The Lower Columbia River Estuary (LCRE) has undergone extensive modifications since the 19th century. Construction of dams, installation of jetties and dikes, dredging of the navigation channel and filling ...

  Citation × Citation Citation Abstract Copy Title: Modeling Historic Columbia River Flood Impacts Author: Helaire, Lumas, Mahedy, Andrew, Talke, Stefan A., Jay, David A Year: 2014 The Lower Columbia River Estuary (LCRE) has undergone extensive modifications since the 19th century. Construction of dams, installation of jetties and dikes, dredging of the navigation channel and filling in of tidal wetlands have all contributed significantly to alterations in tidal dynamics and the flow regime, with consequences for habitat inundation and salinity intrusion. In this talk we discuss the development and implementation of a 19th century flow model for the LCRE, using a digital elevation model based on historic bathymetry. The model has been calibrated with recently rediscovered and digitized tide data from the 19th century. In this research project we look at several river flow scenarios. We are interested in the interaction between river flow and ocean tides, how it has changed in the LCRE since the 19th century and how it affects the river physics. With the model, we focus on the following questions: How has the spatial structure of salinity changed since the 1890's? Has the salinity intrusion length increased or decreased? Is there a change in residual salinity in some of the bays in the estuary? How have changes to the bathymetric structure of the river affected salinity intrusion? For the same flow river flow, how have wetland inundation patterns changed? How have changes to the tidal prism ascertained from a temporal analysis of tidal records, affected the amount of land inundated in a tidal cycle and how long that land remains inundated? Initial results suggest that salinity intrusion patterns have shifted and that wetland inundation patterns have been impacted by the up to 10% increase in the estuary tidal range since the late 19th century. Title: Modeling Historic Columbia River Flood Impacts Author: Helaire, Lumas, Mahedy, Andrew, Talke, Stefan A., Jay, David A Year: 2014 The Lower Columbia River Estuary (LCRE) has undergone extensive modifications since the 19th century. Construction of dams, installation of jetties and dikes, dredging of the navigation channel and filling in of tidal wetlands have all contributed significantly to alterations in tidal dynamics and the flow regime, with consequences for habitat inundation and salinity intrusion. In this talk we discuss the development and implementation of a 19th century flow model for the LCRE, using a digital elevation model based on historic bathymetry. The model has been calibrated with recently rediscovered and digitized tide data from the 19th century. In this research project we look at several river flow scenarios. We are interested in the interaction between river flow and ocean tides, how it has changed in the LCRE since the 19th century and how it affects the river physics. With the model, we focus on the following questions: How has the spatial structure of salinity changed since the 1890's? Has the salinity intrusion length increased or decreased? Is there a change in residual salinity in some of the bays in the estuary? How have changes to the bathymetric structure of the river affected salinity intrusion? For the same flow river flow, how have wetland inundation patterns changed? How have changes to the tidal prism ascertained from a temporal analysis of tidal records, affected the amount of land inundated in a tidal cycle and how long that land remains inundated? Initial results suggest that salinity intrusion patterns have shifted and that wetland inundation patterns have been impacted by the up to 10% increase in the estuary tidal range since the late 19th century. Close