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• 61. [Article] Economic and social impacts of restoration : a case study of the Great Basin Region

  The last five decades of research in arid land ecology cites Invasive species as a source of imbalances in biodiversity through habitat destruction and reductions of native species through ecosystem alterations ...

  Citation × Citation Citation Abstract Copy Title: Economic and social impacts of restoration : a case study of the Great Basin Region Author: Satyal, Vijayanand H. The last five decades of research in arid land ecology cites Invasive species as a source of imbalances in biodiversity through habitat destruction and reductions of native species through ecosystem alterations in favor of non-native species. Invasive species are known to damage not only the surrounding ecosystem but also cause economic and non-economic losses to society. This study focuses on economic and social impacts of controlling cheatgrass (Bromus tectorum L.) on the public rangelands of the Great Basin region. This research seeks to examine the economic and social impacts of adopting different restoration strategies (herbicide use, fire, grazing and re-seeding of native grasses). The economic study seeks to assess the cost-effectiveness of adopting any versus none of the restoration strategies using a linear programming multi-period optimization framework. In order to understand if restoration of cheatgrass is socially acceptable and whether the spatial context influences economic decisions, a parallel social attitudinal study examines the perceptions held by ranchers, interest groups, agency personnel and informed public with regard to restoration, the ongoing collaborative project and expected costs of undertaking restoration. The bio-economic study incorporates ranch production and ecological site specific data into representative optimization models and solves to maximize net ranch income subject to market and resource constraints. The economic study found restoration to impact the ranches financially as the degree of restoration increased. Costs of restoration were lowest under baseline conditions and increased in magnitude with use of grazing, fire, herbicide and the integrated strategy respectively. Attitudinal data indicated that the meaning of restoration and social acceptability towards restoration strategies differed within and across stakeholder groups in the Great Basin states of Oregon, Idaho, Nevada and Utah. Title: Economic and social impacts of restoration : a case study of the Great Basin Region Author: Satyal, Vijayanand H. The last five decades of research in arid land ecology cites Invasive species as a source of imbalances in biodiversity through habitat destruction and reductions of native species through ecosystem alterations in favor of non-native species. Invasive species are known to damage not only the surrounding ecosystem but also cause economic and non-economic losses to society. This study focuses on economic and social impacts of controlling cheatgrass (Bromus tectorum L.) on the public rangelands of the Great Basin region. This research seeks to examine the economic and social impacts of adopting different restoration strategies (herbicide use, fire, grazing and re-seeding of native grasses). The economic study seeks to assess the cost-effectiveness of adopting any versus none of the restoration strategies using a linear programming multi-period optimization framework. In order to understand if restoration of cheatgrass is socially acceptable and whether the spatial context influences economic decisions, a parallel social attitudinal study examines the perceptions held by ranchers, interest groups, agency personnel and informed public with regard to restoration, the ongoing collaborative project and expected costs of undertaking restoration. The bio-economic study incorporates ranch production and ecological site specific data into representative optimization models and solves to maximize net ranch income subject to market and resource constraints. The economic study found restoration to impact the ranches financially as the degree of restoration increased. Costs of restoration were lowest under baseline conditions and increased in magnitude with use of grazing, fire, herbicide and the integrated strategy respectively. Attitudinal data indicated that the meaning of restoration and social acceptability towards restoration strategies differed within and across stakeholder groups in the Great Basin states of Oregon, Idaho, Nevada and Utah. Close

• 62. [Article] Direct effects and tradeoffs affect vegetative growth and sexual reproduction in an invasive seagrass experiencing different disturbance regimes

  Disturbance has both direct and indirect ramifications that can influence species abundance, distribution, and ultimately the diversity found within a community. As a result, we might expect disturbance ...

  Citation × Citation Citation Abstract Copy Title: Direct effects and tradeoffs affect vegetative growth and sexual reproduction in an invasive seagrass experiencing different disturbance regimes Author: Henderson, Jeremy Scott Disturbance has both direct and indirect ramifications that can influence species abundance, distribution, and ultimately the diversity found within a community. As a result, we might expect disturbance to play a particularly important role in the ability of non-native species to proliferate outside of their native range. In practice, disturbance has been shown to facilitate invasions indirectly by reducing competition with established species, but less is known about the direct effects of disturbance on potential invaders. It is generally assumed that the direct effects of disturbance will be negative, but an exemption to this exists if disturbance results in tradeoffs that favor the allocation of resources to sexual reproduction. To examine this possibility, I considered the direct effects of disturbance and the relative importance of tradeoffs on the invasion dynamics of the dwarf eelgrass, Zostera japonica Aschers. & Graebn., across different sediment disturbance regimes in Yaquina Bay, a North American Pacific coast estuary near Newport, Oregon. The basis of my thesis work is a conceptual model in which tradeoffs in resource allocation between reproduction and vegetative growth in plants results in increased sexual reproduction at intermediate levels of disturbance. My hypothesis is that as disturbance severity increases, vegetative biomass declines until there is complete mortality of the population. Moreover, I suggest that flowering biomass will increase with disturbance to some intermediate level but then decline as disturbance severity increases. This increase in flowering biomass is the result of a tradeoff in which individuals reallocate resources from asexual to sexual reproduction as disturbance increases the mortality risk and reduces the fitness of clonal progeny. To test this model, I conducted two years of monthly monitoring at six sites representing the potential for different sediment disturbance regimes, and also conducted a field experiment at three sites representative of low, moderate, and high sediment disturbance. The observational study showed sediment disturbance was strongly site dependent, with three sites having high sedimentation, one site having moderate sedimentation, and two sites having low sedimentation. In the observational and experimental study, there was a negative linear relationship between the abundance (percent cover and biomass) of Z. japonica and sedimentation among the sites. Vegetative growth showed a negative linear response to increased sedimentation, with approximately 50% mortality seen at sediment deposition rates of 1 cm per month, and nearly 100% mortality seen at rates above 3.5 cm per month. The experiment also showed that flowering and seed production responded unimodally to increased sedimentation, and they were greatest at sediment deposition rates of roughly 0.75 cm per month, and effectively inhibited at rates above 1.5 cm per month. My results suggest that the unimodal response of this non-native eelgrass to disturbance is the result of tradeoffs in resource allocation favoring sexual reproduction and the production of seeds, which is potentially an escape from increasing disturbance severity. This type of tradeoff might result in an increased likelihood that Z. japonica could reach new sites, and, as has been shown in other invasive grasses, could possibly result in an increase in genetic diversity that would allow this species to successfully proliferate across a wider range of environmental conditions. As disturbance regimes change due to anthropogenic causes, it is important to document these tradeoffs and determine whether they could contribute to making communities more susceptible to invasion and thus of greater management concern. Title: Direct effects and tradeoffs affect vegetative growth and sexual reproduction in an invasive seagrass experiencing different disturbance regimes Author: Henderson, Jeremy Scott Disturbance has both direct and indirect ramifications that can influence species abundance, distribution, and ultimately the diversity found within a community. As a result, we might expect disturbance to play a particularly important role in the ability of non-native species to proliferate outside of their native range. In practice, disturbance has been shown to facilitate invasions indirectly by reducing competition with established species, but less is known about the direct effects of disturbance on potential invaders. It is generally assumed that the direct effects of disturbance will be negative, but an exemption to this exists if disturbance results in tradeoffs that favor the allocation of resources to sexual reproduction. To examine this possibility, I considered the direct effects of disturbance and the relative importance of tradeoffs on the invasion dynamics of the dwarf eelgrass, Zostera japonica Aschers. & Graebn., across different sediment disturbance regimes in Yaquina Bay, a North American Pacific coast estuary near Newport, Oregon. The basis of my thesis work is a conceptual model in which tradeoffs in resource allocation between reproduction and vegetative growth in plants results in increased sexual reproduction at intermediate levels of disturbance. My hypothesis is that as disturbance severity increases, vegetative biomass declines until there is complete mortality of the population. Moreover, I suggest that flowering biomass will increase with disturbance to some intermediate level but then decline as disturbance severity increases. This increase in flowering biomass is the result of a tradeoff in which individuals reallocate resources from asexual to sexual reproduction as disturbance increases the mortality risk and reduces the fitness of clonal progeny. To test this model, I conducted two years of monthly monitoring at six sites representing the potential for different sediment disturbance regimes, and also conducted a field experiment at three sites representative of low, moderate, and high sediment disturbance. The observational study showed sediment disturbance was strongly site dependent, with three sites having high sedimentation, one site having moderate sedimentation, and two sites having low sedimentation. In the observational and experimental study, there was a negative linear relationship between the abundance (percent cover and biomass) of Z. japonica and sedimentation among the sites. Vegetative growth showed a negative linear response to increased sedimentation, with approximately 50% mortality seen at sediment deposition rates of 1 cm per month, and nearly 100% mortality seen at rates above 3.5 cm per month. The experiment also showed that flowering and seed production responded unimodally to increased sedimentation, and they were greatest at sediment deposition rates of roughly 0.75 cm per month, and effectively inhibited at rates above 1.5 cm per month. My results suggest that the unimodal response of this non-native eelgrass to disturbance is the result of tradeoffs in resource allocation favoring sexual reproduction and the production of seeds, which is potentially an escape from increasing disturbance severity. This type of tradeoff might result in an increased likelihood that Z. japonica could reach new sites, and, as has been shown in other invasive grasses, could possibly result in an increase in genetic diversity that would allow this species to successfully proliferate across a wider range of environmental conditions. As disturbance regimes change due to anthropogenic causes, it is important to document these tradeoffs and determine whether they could contribute to making communities more susceptible to invasion and thus of greater management concern. Close

• 63. [Article] The Effects of Urbanization and Human Disturbance Upon Plant Community Structure and Bird Species Richness, Diversity, and Abundance in a Natural Forested Area (Forest Park) in Portland, Oregon

  The effects of urbanization and continual human disturbance on the plant and avian communities of Forest Park and forested lands surrounding Portland, Oregon, were studied. I examined characteristics of ...

  Citation × Citation Citation Abstract Copy Title: The Effects of Urbanization and Human Disturbance Upon Plant Community Structure and Bird Species Richness, Diversity, and Abundance in a Natural Forested Area (Forest Park) in Portland, Oregon Author: Broshot, Nancy Ellen Year: 1999 The effects of urbanization and continual human disturbance on the plant and avian communities of Forest Park and forested lands surrounding Portland, Oregon, were studied. I examined characteristics of plant and avian communities at 25 sites, 24 which were in Forest Park and surrounding areas and one which was in the Ancient Forest Preserve (old-growth stand) northwest of Forest Park. Data were analyzed using multiple regression, ANOV A, and Bonferonni/Dunn. Seven variables were selected representing different urbanization gradients. An additional covariable coded for the old-growth stand, allowing it to be used as a control. Many tree variables, especially those related to shade-tolerant species, were positively correlated with both the distance from downtown Portland and the number of houses in the surrounding area, and negatively correlated with the distance from the nearest forest edge; however, many shrub and herbaceous variables were negatively correlated with the distance from downtown Portland. Species diversity for herbaceous and shrub species was greater at more urban sites, but diversity of trees was lower at more urban sites. There were significantly more non-native species of plants in the city section. I found significantly fewer saplings and small trees, especially shade-tolerant species, in the section of Forest Park closest to downtown Portland, although tree mortality was positively correlated with distance from Portland. Summer bird data revealed significant increases in the abundances of urban and edge species at more urban sites, with concomitant reductions in forest species. There were significantly more ground gleaning birds and short distance migratory species. I also found a significantly greater abundance of birds in the old-growth stand during the winter. This increase was positively correlated with the depth of snow in the nearby Cascade Mountains. My results indicate that Forest Park is apparently progressing in a normal successional pattern with the exception of the city section. The reduction in shade tolerant saplings and small trees in the city section suggest that rate of succession has been slower at more urban sites. Avian data suggest that urbanization affects bird species abundance and guild composition in the more urban areas. Title: The Effects of Urbanization and Human Disturbance Upon Plant Community Structure and Bird Species Richness, Diversity, and Abundance in a Natural Forested Area (Forest Park) in Portland, Oregon Author: Broshot, Nancy Ellen Year: 1999 The effects of urbanization and continual human disturbance on the plant and avian communities of Forest Park and forested lands surrounding Portland, Oregon, were studied. I examined characteristics of plant and avian communities at 25 sites, 24 which were in Forest Park and surrounding areas and one which was in the Ancient Forest Preserve (old-growth stand) northwest of Forest Park. Data were analyzed using multiple regression, ANOV A, and Bonferonni/Dunn. Seven variables were selected representing different urbanization gradients. An additional covariable coded for the old-growth stand, allowing it to be used as a control. Many tree variables, especially those related to shade-tolerant species, were positively correlated with both the distance from downtown Portland and the number of houses in the surrounding area, and negatively correlated with the distance from the nearest forest edge; however, many shrub and herbaceous variables were negatively correlated with the distance from downtown Portland. Species diversity for herbaceous and shrub species was greater at more urban sites, but diversity of trees was lower at more urban sites. There were significantly more non-native species of plants in the city section. I found significantly fewer saplings and small trees, especially shade-tolerant species, in the section of Forest Park closest to downtown Portland, although tree mortality was positively correlated with distance from Portland. Summer bird data revealed significant increases in the abundances of urban and edge species at more urban sites, with concomitant reductions in forest species. There were significantly more ground gleaning birds and short distance migratory species. I also found a significantly greater abundance of birds in the old-growth stand during the winter. This increase was positively correlated with the depth of snow in the nearby Cascade Mountains. My results indicate that Forest Park is apparently progressing in a normal successional pattern with the exception of the city section. The reduction in shade tolerant saplings and small trees in the city section suggest that rate of succession has been slower at more urban sites. Avian data suggest that urbanization affects bird species abundance and guild composition in the more urban areas. Close

• 64. [Article] Biological Erosion of Marine Habitats and Structures by Burrowing Crustaceans

  Marine bioeroders, borers, and burrowers can have drastic effects to marine habitats and facilities. By physically altering the structure of marine habitats, these organisms may elicit ecosystem-level ...

  Citation × Citation Citation Abstract Copy Title: Biological Erosion of Marine Habitats and Structures by Burrowing Crustaceans Author: Davidson, Timothy Mathias Year: 2011 Marine bioeroders, borers, and burrowers can have drastic effects to marine habitats and facilities. By physically altering the structure of marine habitats, these organisms may elicit ecosystem-level effects that cascade through the community. While borer damage is typically restricted to a few substratum types, burrowing isopods in the genus Sphaeroma attack a diversity of substrata in tropical and temperate systems. My dissertation examined how boring sphaeromatid isopods affect coastal habitats (saltmarshes, mangroves) and other estuarine substrata as well as marine structures. I used a combination of lab and mensurative field experiments to quantify the effects of boring by isopods and examine how select factors affect the colonization, hence burrowing damage by isopods. I explored these questions primarily using the temperate boring sphaeromatid, Sphaeroma quoianum, as a model organism. My initial lab experiments quantified the per capita erosion rates of S. quoianum in four commonly attacked estuarine substrata. I found marsh banks and Styrofoam substrata were the most affected per capita. I supplemented this lab experiment with a year-long mensurative field experiment examining how erosion rates differ between marshes infested and uninfested by boring isopods. Marshes infested with isopods eroded 300% faster than uninfested marshes. I further examined the boring effects on Styrofoam floats. I compiled surveys and observations and conducted a short experiment to describe how isopods affect Styrofoam floats used in floating docks. I observed dense colonies of isopods attacking floats and expelling millions of plastic particles in the ocean. The boring effects to simulated Styrofoam floats were also affected by seawater temperature. Burrowing effects in Styrofoam floats exhibited a curvilinear relationship with temperature and peaked around 18°C. These results suggest a 1-2°C increase in water temperature could increase boring effects 5-17% of populations of isopods in Oregon and California bays. To examine the small-scale factors that mediate colonization and boring, I conducted a series of binary choice experiments. I found the presence of conspecifics, biofilm, and shade were important factors influencing colonization. These small scale factors likely explain why isopod attack is focused in some substrata. Finally, to examine the boring effects of tropical isopods in mangroves, I examined the associations between burrowing by S. terebrans and mangrove performance and fecundity. I found negative relationships between boring effects and performance and fecundity in two mangrove species in a restored mangrove stand in Taiwan. Together, these studies elucidate the effects of bioerosive isopods on saltmarshes, mangroves, and marine structures. However, the similar mechanisms involved in bioerosion in other boring species suggest that these results can be used to infer similar effects of other borers. In addition, since many species of sphaeromatid isopods have been introduced, this research shows how the effects of a non-native bioeroder can damage marine facilities and degrade and alter marine habitats. Through biological erosion and thus changing the physical structure of a marine habitat these non-native species can have ecosystem-level effects that cascade throughout the local community. Title: Biological Erosion of Marine Habitats and Structures by Burrowing Crustaceans Author: Davidson, Timothy Mathias Year: 2011 Marine bioeroders, borers, and burrowers can have drastic effects to marine habitats and facilities. By physically altering the structure of marine habitats, these organisms may elicit ecosystem-level effects that cascade through the community. While borer damage is typically restricted to a few substratum types, burrowing isopods in the genus Sphaeroma attack a diversity of substrata in tropical and temperate systems. My dissertation examined how boring sphaeromatid isopods affect coastal habitats (saltmarshes, mangroves) and other estuarine substrata as well as marine structures. I used a combination of lab and mensurative field experiments to quantify the effects of boring by isopods and examine how select factors affect the colonization, hence burrowing damage by isopods. I explored these questions primarily using the temperate boring sphaeromatid, Sphaeroma quoianum, as a model organism. My initial lab experiments quantified the per capita erosion rates of S. quoianum in four commonly attacked estuarine substrata. I found marsh banks and Styrofoam substrata were the most affected per capita. I supplemented this lab experiment with a year-long mensurative field experiment examining how erosion rates differ between marshes infested and uninfested by boring isopods. Marshes infested with isopods eroded 300% faster than uninfested marshes. I further examined the boring effects on Styrofoam floats. I compiled surveys and observations and conducted a short experiment to describe how isopods affect Styrofoam floats used in floating docks. I observed dense colonies of isopods attacking floats and expelling millions of plastic particles in the ocean. The boring effects to simulated Styrofoam floats were also affected by seawater temperature. Burrowing effects in Styrofoam floats exhibited a curvilinear relationship with temperature and peaked around 18°C. These results suggest a 1-2°C increase in water temperature could increase boring effects 5-17% of populations of isopods in Oregon and California bays. To examine the small-scale factors that mediate colonization and boring, I conducted a series of binary choice experiments. I found the presence of conspecifics, biofilm, and shade were important factors influencing colonization. These small scale factors likely explain why isopod attack is focused in some substrata. Finally, to examine the boring effects of tropical isopods in mangroves, I examined the associations between burrowing by S. terebrans and mangrove performance and fecundity. I found negative relationships between boring effects and performance and fecundity in two mangrove species in a restored mangrove stand in Taiwan. Together, these studies elucidate the effects of bioerosive isopods on saltmarshes, mangroves, and marine structures. However, the similar mechanisms involved in bioerosion in other boring species suggest that these results can be used to infer similar effects of other borers. In addition, since many species of sphaeromatid isopods have been introduced, this research shows how the effects of a non-native bioeroder can damage marine facilities and degrade and alter marine habitats. Through biological erosion and thus changing the physical structure of a marine habitat these non-native species can have ecosystem-level effects that cascade throughout the local community. Close

• 65. [Article] Postfledging Survival and Habitat Use of Spotted Towhees (Pipilo maculatus) in an Urban Park

  Habitat fragmentation, and the resulting increase in edge habitat, has important effects on birds, including the increased probability of nest predation, changes in habitat structure, and the increased ...

  Citation × Citation Citation Abstract Copy Title: Postfledging Survival and Habitat Use of Spotted Towhees (Pipilo maculatus) in an Urban Park Author: Shipley, Amy Ann Year: 2011 Habitat fragmentation, and the resulting increase in edge habitat, has important effects on birds, including the increased probability of nest predation, changes in habitat structure, and the increased presence of non-native plant species. It is critical to understand the effects of fragmentation at all stages of the avian life cycle, including the often overlooked postfledging period. Because much of juvenile mortality occurs during the immediate postfledging period, and juvenile mortality contributes substantially to population dynamics, it is necessary to understand if fledgling survival is reduced in edge habitats and if fledglings' survival is influenced by their habitat use. During 2008 and 2009 I radio-tracked 52 fledgling Spotted Towhees (Pipilo maculatus) during the 30-day postfledging period in a 24-ha urban park near Portland, Oregon. Thirty-six fledglings (69%) survived the 27-day tracking period (an estimated 62.1% survived the entire 30-day postfledging period). At least 9 of 16 predation events were attributable to domestic cats (Felis domesticus) or Western Screech-owls (Megascops kennicottii). Although fledglings were more likely to be found near edges than the park interior, fledglings located closer to park edges had a higher probability of dying. However, I found that towhee nests were more likely to be found near edges, nests near edges produced more fledglings, and nestlings near edges were heavier. I used a STELLA-based stochastic model of nest success and fledgling survival to show that the benefits initially gained by nesting near edges were reversed during the postfledging period. The number of fledglings per nest that survived to the end of the 30-day postfledging period was significantly lower near edges than in the park interior. This apparent preference for nesting near edges, paired with higher fledgling mortality near edges, is consistent with the idea that edges are ecological traps. Fledgling habitat was significantly more structurally dense and had a greater abundance of non-native plant species, particularly Himalayan Blackberry (Rubus armeniacus), than nest habitat. Towhees avoided English Ivy (Hedera helix) for both nesting and care of fledglings. However, fledgling survival was not related to vegetation characteristics, which suggests that increased fledgling mortality near edges was a direct result of increased predator abundance or predation near edges, and was not an artifact of changes in habitat near edges. My results help to establish that fledgling survival and the unique habitat requirements of fledglings should be considered along with nest success and nest habitat when examining the effects of habitat fragmentation on bird populations. More broadly, this study has important implications for conservation, as it exemplifies how phenomena such as ecological traps created by anthropogenic changes in the environment can be overlooked if only one life history stage is studied. Title: Postfledging Survival and Habitat Use of Spotted Towhees (Pipilo maculatus) in an Urban Park Author: Shipley, Amy Ann Year: 2011 Habitat fragmentation, and the resulting increase in edge habitat, has important effects on birds, including the increased probability of nest predation, changes in habitat structure, and the increased presence of non-native plant species. It is critical to understand the effects of fragmentation at all stages of the avian life cycle, including the often overlooked postfledging period. Because much of juvenile mortality occurs during the immediate postfledging period, and juvenile mortality contributes substantially to population dynamics, it is necessary to understand if fledgling survival is reduced in edge habitats and if fledglings' survival is influenced by their habitat use. During 2008 and 2009 I radio-tracked 52 fledgling Spotted Towhees (Pipilo maculatus) during the 30-day postfledging period in a 24-ha urban park near Portland, Oregon. Thirty-six fledglings (69%) survived the 27-day tracking period (an estimated 62.1% survived the entire 30-day postfledging period). At least 9 of 16 predation events were attributable to domestic cats (Felis domesticus) or Western Screech-owls (Megascops kennicottii). Although fledglings were more likely to be found near edges than the park interior, fledglings located closer to park edges had a higher probability of dying. However, I found that towhee nests were more likely to be found near edges, nests near edges produced more fledglings, and nestlings near edges were heavier. I used a STELLA-based stochastic model of nest success and fledgling survival to show that the benefits initially gained by nesting near edges were reversed during the postfledging period. The number of fledglings per nest that survived to the end of the 30-day postfledging period was significantly lower near edges than in the park interior. This apparent preference for nesting near edges, paired with higher fledgling mortality near edges, is consistent with the idea that edges are ecological traps. Fledgling habitat was significantly more structurally dense and had a greater abundance of non-native plant species, particularly Himalayan Blackberry (Rubus armeniacus), than nest habitat. Towhees avoided English Ivy (Hedera helix) for both nesting and care of fledglings. However, fledgling survival was not related to vegetation characteristics, which suggests that increased fledgling mortality near edges was a direct result of increased predator abundance or predation near edges, and was not an artifact of changes in habitat near edges. My results help to establish that fledgling survival and the unique habitat requirements of fledglings should be considered along with nest success and nest habitat when examining the effects of habitat fragmentation on bird populations. More broadly, this study has important implications for conservation, as it exemplifies how phenomena such as ecological traps created by anthropogenic changes in the environment can be overlooked if only one life history stage is studied. Close

• 66. [Article] Invasive bullfrog use of novel ephemeral habitats in the Pacific Northwest

  Invasive species are a major threat to global biodiversity. Understanding the mechanisms underlying successful invasions is imperative for developing effective management strategies. Plasticity in physiological, ...

  Citation × Citation Citation Abstract Copy Title: Invasive bullfrog use of novel ephemeral habitats in the Pacific Northwest Author: Cook, Megan Tetsuko Invasive species are a major threat to global biodiversity. Understanding the mechanisms underlying successful invasions is imperative for developing effective management strategies. Plasticity in physiological, morphological, and behavioral traits could be an indicator of invasion potential in non-native species. The invasive American bullfrog (Lithobates catesbeianus) has recently been observed breeding in ephemeral wetlands in the Willamette Valley, OR, which represents a shift from typical breeding sites in its native range. We hypothesized that plasticity in larval growth and development rates in response to ephemeral hydroperiod conditions has facilitated invasion into this novel habitat. In addition, we hypothesized that invasive bullfrogs would respond with plastic changes in behavior to a novel predator in ephemeral wetlands, the larval long-toed salamander (Ambystoma macrodactylum). First, we tested physiological plasticity in invasive bullfrog larvae with a 6 x 3 factorial mesocosm experiment. We quantified growth and development rates of 6 bullfrog clutches in response to 3 hydroperiod treatments. We found no differences due to hydroperiod treatments, but we found significant differences in growth between clutches. Clutch differences in growth could lead to population-level differences in the ability to invade ephemeral wetlands. We also tested behavioral plasticity in larval bullfrog response to A. macrodactylum chemical cues. We hypothesized that bullfrogs would reduce activity levels in response to predator chemical cues but we found no differences in activity or spatial orientation due to predator treatment. Instead, we found that bullfrog activity and spatial orientation were positively associated with bullfrog size. This indicates bullfrog larvae do not recognize predatory chemical cues from A. macrodactylum. Together, these results indicate that bullfrog populations will vary significantly in their invasion success into ephemeral wetlands. Further study of local variation in growth and development rates and site fidelity to ephemeral wetlands is needed to determine threats to ephemeral wetlands by bullfrog invasion. Title: Invasive bullfrog use of novel ephemeral habitats in the Pacific Northwest Author: Cook, Megan Tetsuko Invasive species are a major threat to global biodiversity. Understanding the mechanisms underlying successful invasions is imperative for developing effective management strategies. Plasticity in physiological, morphological, and behavioral traits could be an indicator of invasion potential in non-native species. The invasive American bullfrog (Lithobates catesbeianus) has recently been observed breeding in ephemeral wetlands in the Willamette Valley, OR, which represents a shift from typical breeding sites in its native range. We hypothesized that plasticity in larval growth and development rates in response to ephemeral hydroperiod conditions has facilitated invasion into this novel habitat. In addition, we hypothesized that invasive bullfrogs would respond with plastic changes in behavior to a novel predator in ephemeral wetlands, the larval long-toed salamander (Ambystoma macrodactylum). First, we tested physiological plasticity in invasive bullfrog larvae with a 6 x 3 factorial mesocosm experiment. We quantified growth and development rates of 6 bullfrog clutches in response to 3 hydroperiod treatments. We found no differences due to hydroperiod treatments, but we found significant differences in growth between clutches. Clutch differences in growth could lead to population-level differences in the ability to invade ephemeral wetlands. We also tested behavioral plasticity in larval bullfrog response to A. macrodactylum chemical cues. We hypothesized that bullfrogs would reduce activity levels in response to predator chemical cues but we found no differences in activity or spatial orientation due to predator treatment. Instead, we found that bullfrog activity and spatial orientation were positively associated with bullfrog size. This indicates bullfrog larvae do not recognize predatory chemical cues from A. macrodactylum. Together, these results indicate that bullfrog populations will vary significantly in their invasion success into ephemeral wetlands. Further study of local variation in growth and development rates and site fidelity to ephemeral wetlands is needed to determine threats to ephemeral wetlands by bullfrog invasion. Close

• 67. [Image] Bull trout restoration and brook trout eradication at Crater Lake National Park, Oregon

  	ill., 1 map (sketched) ; Report title; "Drought conditions are continuing in 1994, at the writing of this report in March of 1994, Crater Lake National Park had received approximately 50% of the annual ...
  	Citation × Citation Citation Abstract Copy Title: Bull trout restoration and brook trout eradication at Crater Lake National Park, Oregon Author: Buktenica, Mark. Year: 1994, 2008, 2009 ill., 1 map (sketched) ; Report title; "Drought conditions are continuing in 1994, at the writing of this report in March of 1994, Crater Lake National Park had received approximately 50% of the annual average accumulated precipatation to date." - P. 17.; Title: Bull trout restoration and brook trout eradication at Crater Lake National Park, Oregon Author: Buktenica, Mark. Year: 1994, 2008, 2009 ill., 1 map (sketched) ; Report title; "Drought conditions are continuing in 1994, at the writing of this report in March of 1994, Crater Lake National Park had received approximately 50% of the annual average accumulated precipatation to date." - P. 17.; Close

• 68. [Article] Temporal Genetic Variance and Propagule-Driven Genetic Structure Characterize Naturalized Rainbow Trout (Oncorhynchus mykiss) from a Patagonian Lake Impacted by Trout Farming

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Public Library of Science. The published article can be found at: http://www.plosone.org/

  Citation × Citation Citation Abstract Copy Title: Temporal Genetic Variance and Propagule-Driven Genetic Structure Characterize Naturalized Rainbow Trout (Oncorhynchus mykiss) from a Patagonian Lake Impacted by Trout Farming Author: Arismendi, Ivan, Seeb, Lisa W., Seeb, James E., et al., Benavente, Javiera N. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Public Library of Science. The published article can be found at: http://www.plosone.org/ Title: Temporal Genetic Variance and Propagule-Driven Genetic Structure Characterize Naturalized Rainbow Trout (Oncorhynchus mykiss) from a Patagonian Lake Impacted by Trout Farming Author: Arismendi, Ivan, Seeb, Lisa W., Seeb, James E., et al., Benavente, Javiera N. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Public Library of Science. The published article can be found at: http://www.plosone.org/ Close

• 69. [Article] Comparing vegetation and soils of remnant and restored prairie wetlands in the northern Willamette Valley

  Native prairies of the Willamette Valley are considered among the rarest of Oregon's ecosystems (Clark and Wilson, 2001). As a result of agriculture conversion, urban development and cessation of native ...

  Citation × Citation Citation Abstract Copy Title: Comparing vegetation and soils of remnant and restored prairie wetlands in the northern Willamette Valley Author: Taylor, Sara M. Native prairies of the Willamette Valley are considered among the rarest of Oregon's ecosystems (Clark and Wilson, 2001). As a result of agriculture conversion, urban development and cessation of native burning, Willamette Valley prairies have become highly fragmented and invaded by non-native species, leaving little room for native plant diversity. Even though wetland prairie conservation and restoration has been a priority for many government agencies there is a need for research on what restoration techniques and management are necessary for increasing native species richness and abundance in remnant and restored wet prairie sites. In this research project, two studies were conducted. In the first study, data were collected on species presence and abundance from three 100m² randomized plots within three remnant wet prairies (Green Mountain, Gotter Prairie South, Knez) and three restored wet prairies (Hutchinson, Gotter Prairie North, Lovejoy) to answer the following research question, 'Are there differences between remnant and restored prairie plant communities with respect to the diversity and abundance of native species?' Analysis of variance and multivariate ordination techniques were used to assess the ecological differences between uncultivated, minimally-managed remnant wet prairies and newly-restored, highly managed wet prairies. Data on soils collected from agricultural sites (Westbrook, Zurcher, Gotter Prairie Ag), as well as the remnant and restored wet prairies mentioned above, were also used to compare soil quality and processes with the remnant and restored wetlands. Restored wet prairie had 23% higher native species cover than remnant prairie (p-value=0.089, N=6). Remnant and restored sites did not differ in native species richness (p-value=0.949, N=6). The relatively high per cent cover of native species at restored sites, (significant at the 10% level), suggests that land managers have successfully restored agricultural properties with an abundance of native species. The lack of significant difference in native species richness between remnant and restored sites also suggests that land managers have also been able to restore native plant diversity into former agricultural properties equivalent to some of the best intact remnant prairies within the Northern Willamette Valley in a short period of time (8 years or less). However, a non-metric scaling (NMS) ordination of the species matrix separated the remnant sites from the restored sites, suggesting that community composition distinguishes restored sites from remnants. The NMS results, which include environmental data in the analysis, also suggest that there is a positive correlation of percent soil moisture and percent soil organic matter associated with the remnant prairies and a positive correlation of management practices such as yearly chemical use, mowing, and clean crops, associated with the restored prairies. The location of Gotter Prairie North restoration within the ordination, between the remnant and restored sites, suggests an intermediate plant composition and soil quality. This could be attributed to intensive weed suppression and soil organic matter build up over time (8 years) in comparison to younger restored sites (3 and 4 years). Indicator species analysis identified many species with high indicator values (IVs) in the remnant prairies; Holcus lanatus, Deschampsia cespitosa, Carex densa and Phalaris arundinacea being the highest. The use of fire as a management tool produced only one species with a high IV (Camassia quamash). In the second study, three seeding treatments (Grass first, Grass and Forb together, Forb first) were compared within a 4 hectare experimental wet prairie unit to answer the research question „Which of the three seeding treatments used leads to the highest native species abundance and species richness?‟ Results from an analysis of variance indicated significant differences between treatments in native species richness for 2009 and 2010 (p-values=0.002 & 0.004 respectively) at the 5% level and native species abundance in 2010 only (p-value=0.099) at the 10% level. The Grass and Forb and Forb first treatments were highest in native species richness for 2009 and 2010, whereas the Grass and Forb and Grass first treatments were highest in native species abundance in 2010. A NMS ordination suggests that Juncus tenuis is one of the dominant species, in all seeding treatments, after one year of growth. Title: Comparing vegetation and soils of remnant and restored prairie wetlands in the northern Willamette Valley Author: Taylor, Sara M. Native prairies of the Willamette Valley are considered among the rarest of Oregon's ecosystems (Clark and Wilson, 2001). As a result of agriculture conversion, urban development and cessation of native burning, Willamette Valley prairies have become highly fragmented and invaded by non-native species, leaving little room for native plant diversity. Even though wetland prairie conservation and restoration has been a priority for many government agencies there is a need for research on what restoration techniques and management are necessary for increasing native species richness and abundance in remnant and restored wet prairie sites. In this research project, two studies were conducted. In the first study, data were collected on species presence and abundance from three 100m² randomized plots within three remnant wet prairies (Green Mountain, Gotter Prairie South, Knez) and three restored wet prairies (Hutchinson, Gotter Prairie North, Lovejoy) to answer the following research question, 'Are there differences between remnant and restored prairie plant communities with respect to the diversity and abundance of native species?' Analysis of variance and multivariate ordination techniques were used to assess the ecological differences between uncultivated, minimally-managed remnant wet prairies and newly-restored, highly managed wet prairies. Data on soils collected from agricultural sites (Westbrook, Zurcher, Gotter Prairie Ag), as well as the remnant and restored wet prairies mentioned above, were also used to compare soil quality and processes with the remnant and restored wetlands. Restored wet prairie had 23% higher native species cover than remnant prairie (p-value=0.089, N=6). Remnant and restored sites did not differ in native species richness (p-value=0.949, N=6). The relatively high per cent cover of native species at restored sites, (significant at the 10% level), suggests that land managers have successfully restored agricultural properties with an abundance of native species. The lack of significant difference in native species richness between remnant and restored sites also suggests that land managers have also been able to restore native plant diversity into former agricultural properties equivalent to some of the best intact remnant prairies within the Northern Willamette Valley in a short period of time (8 years or less). However, a non-metric scaling (NMS) ordination of the species matrix separated the remnant sites from the restored sites, suggesting that community composition distinguishes restored sites from remnants. The NMS results, which include environmental data in the analysis, also suggest that there is a positive correlation of percent soil moisture and percent soil organic matter associated with the remnant prairies and a positive correlation of management practices such as yearly chemical use, mowing, and clean crops, associated with the restored prairies. The location of Gotter Prairie North restoration within the ordination, between the remnant and restored sites, suggests an intermediate plant composition and soil quality. This could be attributed to intensive weed suppression and soil organic matter build up over time (8 years) in comparison to younger restored sites (3 and 4 years). Indicator species analysis identified many species with high indicator values (IVs) in the remnant prairies; Holcus lanatus, Deschampsia cespitosa, Carex densa and Phalaris arundinacea being the highest. The use of fire as a management tool produced only one species with a high IV (Camassia quamash). In the second study, three seeding treatments (Grass first, Grass and Forb together, Forb first) were compared within a 4 hectare experimental wet prairie unit to answer the research question „Which of the three seeding treatments used leads to the highest native species abundance and species richness?‟ Results from an analysis of variance indicated significant differences between treatments in native species richness for 2009 and 2010 (p-values=0.002 & 0.004 respectively) at the 5% level and native species abundance in 2010 only (p-value=0.099) at the 10% level. The Grass and Forb and Forb first treatments were highest in native species richness for 2009 and 2010, whereas the Grass and Forb and Grass first treatments were highest in native species abundance in 2010. A NMS ordination suggests that Juncus tenuis is one of the dominant species, in all seeding treatments, after one year of growth. Close

• 70. [Article] Grassland Arthropods Are Controlled by Direct and Indirect Interactions with Cattle but Are Largely Unaffected by Plant Provenance

  Supporting information is located at: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0129823#sec011

  Citation × Citation Citation Abstract Copy Title: Grassland Arthropods Are Controlled by Direct and Indirect Interactions with Cattle but Are Largely Unaffected by Plant Provenance Author: Suding, Katharine N., Farrell, Kelly Anne, Borer, Elizabeth T., Harpole, W. Stanley, Stein, Claudia Supporting information is located at: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0129823#sec011 Title: Grassland Arthropods Are Controlled by Direct and Indirect Interactions with Cattle but Are Largely Unaffected by Plant Provenance Author: Suding, Katharine N., Farrell, Kelly Anne, Borer, Elizabeth T., Harpole, W. Stanley, Stein, Claudia Supporting information is located at: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0129823#sec011 Close

• 71. [Article] Recommendations for Control of Tall Oatgrass, Poison Oak, and Rose in Willamette Valley Upland Prairies

  Native upland prairies, which once dominated the landscape of the Willamette Valley, are considered among the rarest of Oregon's ecosystems. Even though only remnants remain today, they harbor many rare ...

  Citation × Citation Citation Abstract Copy Title: Recommendations for Control of Tall Oatgrass, Poison Oak, and Rose in Willamette Valley Upland Prairies Author: Wilson, Mark V., Clark, Deborah Louise, 1950- Native upland prairies, which once dominated the landscape of the Willamette Valley, are considered among the rarest of Oregon's ecosystems. Even though only remnants remain today, they harbor many rare and endangered species such as the Fender's blue butterfly and its host plant, Kincaid’s lupine. Invasion of remnant prairies by woody plants and weedy non-native herbaceous species is of great concern to agencies and managers responsible for conserving these native ecosystems. Available methods for the control of these pests include herbicides, biological control, prescribed burning, and mowing. This report first reviews the literature on the control of tall oatgrass and the shrubs poison oak and rose. Each of these species is an important threat to Willamette Valley upland prairies. We then presents recommendations. For control of tall oatgrass, we recommend for most situations mowing in late spring or early summer. Mowing height should be just above most of the foliage of native plants to be protected (typically 10 cm - 15 cm). In areas with Kincaid’s lupine and Fender’s blue butterfly, mowing should be delayed until July, after the flowering and flight seasons. For control of prairie shrubs, we recommend further studies to evaluate herbicide effectiveness against the target shrubs and safety for non-target native plants and animals. If herbicide use is unavailable, we recommend burning or mowing. All burning or mowing treatments should be repeated, perhaps indefinitely, to maintain pest plant control. Title: Recommendations for Control of Tall Oatgrass, Poison Oak, and Rose in Willamette Valley Upland Prairies Author: Wilson, Mark V., Clark, Deborah Louise, 1950- Native upland prairies, which once dominated the landscape of the Willamette Valley, are considered among the rarest of Oregon's ecosystems. Even though only remnants remain today, they harbor many rare and endangered species such as the Fender's blue butterfly and its host plant, Kincaid’s lupine. Invasion of remnant prairies by woody plants and weedy non-native herbaceous species is of great concern to agencies and managers responsible for conserving these native ecosystems. Available methods for the control of these pests include herbicides, biological control, prescribed burning, and mowing. This report first reviews the literature on the control of tall oatgrass and the shrubs poison oak and rose. Each of these species is an important threat to Willamette Valley upland prairies. We then presents recommendations. For control of tall oatgrass, we recommend for most situations mowing in late spring or early summer. Mowing height should be just above most of the foliage of native plants to be protected (typically 10 cm - 15 cm). In areas with Kincaid’s lupine and Fender’s blue butterfly, mowing should be delayed until July, after the flowering and flight seasons. For control of prairie shrubs, we recommend further studies to evaluate herbicide effectiveness against the target shrubs and safety for non-target native plants and animals. If herbicide use is unavailable, we recommend burning or mowing. All burning or mowing treatments should be repeated, perhaps indefinitely, to maintain pest plant control. Close

• 72. [Article] Westside Salem integrated non-native plant management plan environmental assessment and finding of no significant impact

  99 pp. Map, tables, references, appendices. The project area is located on federal lands (approximately 232,332 acres) managed by the MP and Tillamook RAs, Salem District of the BLM and private lands located ...

  Citation × Citation Citation Abstract Copy Title: Westside Salem integrated non-native plant management plan environmental assessment and finding of no significant impact Author: United States. Bureau of Land Management. Salem District Year: 2009, 2008 99 pp. Map, tables, references, appendices. The project area is located on federal lands (approximately 232,332 acres) managed by the MP and Tillamook RAs, Salem District of the BLM and private lands located within the boundaries of these resource areas located west of the Willamette Valley, Oregon in Benton, Clatsop, Columbia, Lane, Lincoln, Multnomah, Polk, Tillamook, Washington and Yamhill Counties. Captured January 23, 2008 Title: Westside Salem integrated non-native plant management plan environmental assessment and finding of no significant impact Author: United States. Bureau of Land Management. Salem District Year: 2009, 2008 99 pp. Map, tables, references, appendices. The project area is located on federal lands (approximately 232,332 acres) managed by the MP and Tillamook RAs, Salem District of the BLM and private lands located within the boundaries of these resource areas located west of the Willamette Valley, Oregon in Benton, Clatsop, Columbia, Lane, Lincoln, Multnomah, Polk, Tillamook, Washington and Yamhill Counties. Captured January 23, 2008 Close

• 73. [Article] Neacoxie Watershed

  Abstract -- Previously, little information was known about the ecology or the condition of native habitats in the Neacoxie sub-watershed that drains from the city of Warrenton into the north section of ...

  Citation × Citation Citation Abstract Copy Title: Neacoxie Watershed Abstract -- Previously, little information was known about the ecology or the condition of native habitats in the Neacoxie sub-watershed that drains from the city of Warrenton into the north section of the Necanicum Estuary in the city of Seaside. In 2002, the Necanicum Watershed Council completed an assessment for the Necanicum River watershed, but with major knowledge gaps for the Neacoxie watershed, which includes the Neacoxie Creek corridor and the Clatsop Plains. In order for the North Coast Land Conservancy (NCLC) and other land managers to develop stewardship priorities and to make informed decisions about land management actions in this region, additional information was required. Together with the Necanicum Watershed Council and the North Coast Watershed Association, NCLC secured funding to conduct habitat inventories of the Neacoxie watershed. The Neacoxie Watershed Assessment summarizes the results of terrestrial plant transects and aquatic plant surveys completed in the summer of 2011 on ten properties owned by the North Coast Land Conservancy (NCLC) in the Neacoxie Creek watershed (please refer to Appendices A & B). Habitat types include stabilized sand dunes dominated by coastal prairie habitat, interdunal wetland swales and lakes, upland Sitka spruce forest, and forested wetlands. Percent composition of each plant community type observed was calculated. Invasive non-native plant species were recorded. Surveys were also conducted for both native and non-native plants in four water bodies owned by NCLC or adjacent to land trust properties. The plant community data that were collected will be used to evaluate baseline ecological conditions in the Neacoxie watershed. Plant communities can be used as indicators of long-term tidal and hydrologic conditions as well as the ecological health of the landscape. Repeated measurements can be used to assess community changes over time and to assess how plant community composition compares to that described for natural conditions. This information will assist the land trust in making science-based stewardship decisions on its properties, and can be used by other landowners to better understand changes occurring in plant communities in similar habitats on their properties as a result of human disturbance (e.g., land development, farming, grazing) and invasion by non-native plants. Title: Neacoxie Watershed Abstract -- Previously, little information was known about the ecology or the condition of native habitats in the Neacoxie sub-watershed that drains from the city of Warrenton into the north section of the Necanicum Estuary in the city of Seaside. In 2002, the Necanicum Watershed Council completed an assessment for the Necanicum River watershed, but with major knowledge gaps for the Neacoxie watershed, which includes the Neacoxie Creek corridor and the Clatsop Plains. In order for the North Coast Land Conservancy (NCLC) and other land managers to develop stewardship priorities and to make informed decisions about land management actions in this region, additional information was required. Together with the Necanicum Watershed Council and the North Coast Watershed Association, NCLC secured funding to conduct habitat inventories of the Neacoxie watershed. The Neacoxie Watershed Assessment summarizes the results of terrestrial plant transects and aquatic plant surveys completed in the summer of 2011 on ten properties owned by the North Coast Land Conservancy (NCLC) in the Neacoxie Creek watershed (please refer to Appendices A & B). Habitat types include stabilized sand dunes dominated by coastal prairie habitat, interdunal wetland swales and lakes, upland Sitka spruce forest, and forested wetlands. Percent composition of each plant community type observed was calculated. Invasive non-native plant species were recorded. Surveys were also conducted for both native and non-native plants in four water bodies owned by NCLC or adjacent to land trust properties. The plant community data that were collected will be used to evaluate baseline ecological conditions in the Neacoxie watershed. Plant communities can be used as indicators of long-term tidal and hydrologic conditions as well as the ecological health of the landscape. Repeated measurements can be used to assess community changes over time and to assess how plant community composition compares to that described for natural conditions. This information will assist the land trust in making science-based stewardship decisions on its properties, and can be used by other landowners to better understand changes occurring in plant communities in similar habitats on their properties as a result of human disturbance (e.g., land development, farming, grazing) and invasion by non-native plants. Close

• 74. [Article] Westside Salem integrated non-native plant management plan final decision and decision rationale

  22 pp. Tables, map. The project area is located on federal lands (approximately 232,332 acres) managed by the MP and Tillamook RAs, Salem District of the BLM and private lands located within the boundaries ...

  Citation × Citation Citation Abstract Copy Title: Westside Salem integrated non-native plant management plan final decision and decision rationale Author: United States. Bureau of Land Management. Salem District Year: 2009, 2008 22 pp. Tables, map. The project area is located on federal lands (approximately 232,332 acres) managed by the MP and Tillamook RAs, Salem District of the BLM and private lands located within the boundaries of these resource areas located west of the Willamette Valley, Oregon in Benton, Clatsop, Columbia, Lane, Lincoln, Multnomah, Polk, Tillamook, Washington and Yamhill Counties. Captured July 7, 2008. Title: Westside Salem integrated non-native plant management plan final decision and decision rationale Author: United States. Bureau of Land Management. Salem District Year: 2009, 2008 22 pp. Tables, map. The project area is located on federal lands (approximately 232,332 acres) managed by the MP and Tillamook RAs, Salem District of the BLM and private lands located within the boundaries of these resource areas located west of the Willamette Valley, Oregon in Benton, Clatsop, Columbia, Lane, Lincoln, Multnomah, Polk, Tillamook, Washington and Yamhill Counties. Captured July 7, 2008. Close

• 75. [Article] The Ecology and Demography of the Invasive Ascidian Botrylloides violaceus in the Coos Estuary

  133 pages. A thesis presented to the Department of Biology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring ...

  Citation × Citation Citation Abstract Copy Title: The Ecology and Demography of the Invasive Ascidian Botrylloides violaceus in the Coos Estuary Author: Dorning, Sandra Lynn Year: 2017 133 pages. A thesis presented to the Department of Biology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2017 Title: The Ecology and Demography of the Invasive Ascidian Botrylloides violaceus in the Coos Estuary Author: Dorning, Sandra Lynn Year: 2017 133 pages. A thesis presented to the Department of Biology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2017 Close

• 76. [Article] The Effect of Temperature on Phenotypes of the Invasive European Green Crab: Physiologic Mechanisms that Facilitate Invasion Success

  Invasion physiology is an emerging field that endeavors to understand the influence of physiological traits on the establishment of non-native species in novel environments. The invasive European green ...

  Citation × Citation Citation Abstract Copy Title: The Effect of Temperature on Phenotypes of the Invasive European Green Crab: Physiologic Mechanisms that Facilitate Invasion Success Author: Kelley, Amanda Year: 2013 Invasion physiology is an emerging field that endeavors to understand the influence of physiological traits on the establishment of non-native species in novel environments. The invasive European green crab,Carcinus maenas, is one of the world's most successful aquatic invaders, and is currently distributed across temperate marine ecosystems globally. The work presented here explored the thermal physiology of this species, and has highlighted several physiological traits that have likely influenced establishment success. Intraspecific comparisons of crabs sampled from the northern and southern edges of their recipient, or invaded range on the west coast of North America have identified both organismal and cellular physiological difference with respect to upper and lower thermal tolerances. Crabs sampled from British Columbia, Canada (BC) had a significantly lower mean upper thermal tolerance threshold and heat shock protein synthesis, Hsp70, compared to their warm acclimated conspecifics sampled from California (CA). These differential physiologic responses may be rooted in the disparate natural thermal habitats that each population occupies within their respective environments. The ability of this species to extend its current range limits was also investigated. Range expansion to the south has been limited, and is likely restricted by this species lack of adaptation to warmer temperatures. Because range expansion has been chiefly northward, characterizing this species' response to cold stress can identify whether colder temperatures poleward may limit further range expansion. Cold tolerance capacity was determined in the laboratory, and crabs sampled from Vancouver Island, British Columbia were able to withstand the over-wintering thermal regime that occurs in Sitka, Alaska, a site that is currently beyond the range limits of this species. Furthermore, intraspecific assessments found that the cold acclimated BC population exposed to cold shock significantly down regulated protein levels of cyclin D1, cell cycle modulator. Distinct differences in carapace width (CW) were detected along the thermal gradient present in the green crabs' range. This variation in body size was utilized to the test the temperature size rule hypothesis for ectotherms. Simply stated, the temperature size rule is the tendency for ectotherms to develop slower but mature to a larger body sizes at cooler temperatures. The results supported this hypothesis as crabs sampled from the warm portion of the range were found to be smaller than crabs sampled from the colder portion of the range. This pattern was detected along the native range as well. Differences in body size have the potential to influence the scope of invasion; larger individuals are generally more fecund and longer lived, which can increase both the intensity and frequency of larval dispersal that could further propel range expansion. The physiologic properties that the green crab possesses which may influence invasion success were examined using peer-reviewed literature with the aim of determining if these physiological traits confer invasion success across taxa. This analysis tested four hypotheses: 1) Broad geographic temperature tolerances (thermal width) confer a higher upper thermal tolerance threshold when comparing invasive and native species. 2) The upper thermal extreme experienced in nature is correlated with upper thermal tolerance threshold. 3) Protein chaperone expression, a cellular mechanism underlying thermal tolerance threshold, is greater in invasive organisms than in native ones. 4) Acclimation to higher temperatures can promote a greater range of thermal tolerance for invasives compared to natives. These preliminary results generally support the four stated hypotheses, and provide a solid foundation for further studies to explore and identify physiologic traits that facilitate invasion success. Overall, these studies investigated the thermal physiology ofCarcinus maenasfrom an invasive metapopulation and have brought about significant advances in our understanding of what physiologic traits correlate to invasion success in this species. In addition, the data presented here can aid resource managers in identifying habitats, based on thermal tolerance measurements that fit the criteria for invasion. Understanding how invasive organisms vary with respect to thermal tolerance can aid our understanding the patterns and processes of species invasions. Title: The Effect of Temperature on Phenotypes of the Invasive European Green Crab: Physiologic Mechanisms that Facilitate Invasion Success Author: Kelley, Amanda Year: 2013 Invasion physiology is an emerging field that endeavors to understand the influence of physiological traits on the establishment of non-native species in novel environments. The invasive European green crab,Carcinus maenas, is one of the world's most successful aquatic invaders, and is currently distributed across temperate marine ecosystems globally. The work presented here explored the thermal physiology of this species, and has highlighted several physiological traits that have likely influenced establishment success. Intraspecific comparisons of crabs sampled from the northern and southern edges of their recipient, or invaded range on the west coast of North America have identified both organismal and cellular physiological difference with respect to upper and lower thermal tolerances. Crabs sampled from British Columbia, Canada (BC) had a significantly lower mean upper thermal tolerance threshold and heat shock protein synthesis, Hsp70, compared to their warm acclimated conspecifics sampled from California (CA). These differential physiologic responses may be rooted in the disparate natural thermal habitats that each population occupies within their respective environments. The ability of this species to extend its current range limits was also investigated. Range expansion to the south has been limited, and is likely restricted by this species lack of adaptation to warmer temperatures. Because range expansion has been chiefly northward, characterizing this species' response to cold stress can identify whether colder temperatures poleward may limit further range expansion. Cold tolerance capacity was determined in the laboratory, and crabs sampled from Vancouver Island, British Columbia were able to withstand the over-wintering thermal regime that occurs in Sitka, Alaska, a site that is currently beyond the range limits of this species. Furthermore, intraspecific assessments found that the cold acclimated BC population exposed to cold shock significantly down regulated protein levels of cyclin D1, cell cycle modulator. Distinct differences in carapace width (CW) were detected along the thermal gradient present in the green crabs' range. This variation in body size was utilized to the test the temperature size rule hypothesis for ectotherms. Simply stated, the temperature size rule is the tendency for ectotherms to develop slower but mature to a larger body sizes at cooler temperatures. The results supported this hypothesis as crabs sampled from the warm portion of the range were found to be smaller than crabs sampled from the colder portion of the range. This pattern was detected along the native range as well. Differences in body size have the potential to influence the scope of invasion; larger individuals are generally more fecund and longer lived, which can increase both the intensity and frequency of larval dispersal that could further propel range expansion. The physiologic properties that the green crab possesses which may influence invasion success were examined using peer-reviewed literature with the aim of determining if these physiological traits confer invasion success across taxa. This analysis tested four hypotheses: 1) Broad geographic temperature tolerances (thermal width) confer a higher upper thermal tolerance threshold when comparing invasive and native species. 2) The upper thermal extreme experienced in nature is correlated with upper thermal tolerance threshold. 3) Protein chaperone expression, a cellular mechanism underlying thermal tolerance threshold, is greater in invasive organisms than in native ones. 4) Acclimation to higher temperatures can promote a greater range of thermal tolerance for invasives compared to natives. These preliminary results generally support the four stated hypotheses, and provide a solid foundation for further studies to explore and identify physiologic traits that facilitate invasion success. Overall, these studies investigated the thermal physiology ofCarcinus maenasfrom an invasive metapopulation and have brought about significant advances in our understanding of what physiologic traits correlate to invasion success in this species. In addition, the data presented here can aid resource managers in identifying habitats, based on thermal tolerance measurements that fit the criteria for invasion. Understanding how invasive organisms vary with respect to thermal tolerance can aid our understanding the patterns and processes of species invasions. Close

• 77. [Article] Identification of optimal broodstock for Pacific Northwest oysters

  The United States Pacific Northwest is well known for its shellfish farming. Historically, commercial harvests were dominated by the native Olympia oyster, Ostrea lurida, but over-exploitation, habitat ...

  Citation × Citation Citation Abstract Copy Title: Identification of optimal broodstock for Pacific Northwest oysters Author: Stick, David A. The United States Pacific Northwest is well known for its shellfish farming. Historically, commercial harvests were dominated by the native Olympia oyster, Ostrea lurida, but over-exploitation, habitat degradation, and competition and predation by non-native species has drastically depleted their densities and extirpated many local populations. As a result, shellfish aquaculture production has shifted to the introduced Pacific oyster, Crassostrea gigas. An underlying objective of this dissertation is the use of molecular genetics to improve our ability to accurately identifying optimal oyster broodstock for either restoration of Olympia oysters or farming of Pacific oysters. The ecological benefits provided by oysters as well as the Olympia oyster's historical significance, has motivated numerous restoration/supplementation efforts but these efforts are proceeding without a clear understanding of the genetic structure among extant populations, which could be substantial as a consequence of limited dispersal, local adaptation and/or anthropogenic impacts. To facilitate this understanding, we isolated and characterized 19 polymorphic microsatellites and used 8 of these to study the genetic structure of 2,712 individuals collected from 25 remnant Olympia oyster populations between the northern tip of Vancouver Island BC and Elkhorn Slough CA. Gene flow among geographically separated extant Olympia oyster populations is surprisingly limited for a marine invertebrate species whose free-swimming larvae are capable of planktonic dispersal as long as favorable water conditions exist. We found a significant correlation between geographic and genetic distances supporting the premise that coastal populations are isolated by distance. Genetic structure among remnant populations was not limited to broad geographic regions but was also present at sub-regional scales in both Puget Sound WA and San Francisco Bay CA. Until it can be determined whether genetically differentiated O. lurida populations are locally adapted, restoration projects and resource managers should be cautious of random mixing or transplantation of stocks where gene flow is restricted. As we transition from our Olympia oyster population analysis to our Pacific oyster quantitative analysis, we recognize that traditional quantitative trait locus (QTL) mapping strategies use crosses among inbred lines to create segregating populations. Unfortunately, even low levels of inbreeding in the Pacific oyster (Crassostrea gigas) can substantially depress economically important quantitative traits such as yield and survival, potentially complicating subsequent QTL analyses. To circumvent this problem, we constructed an integrated linkage map for Pacific oysters, consisting of 65 microsatellite (18 of which were previously unmapped) and 212 AFLP markers using a full-sib cross between phenotypically differentiated outbred families. We identified 10 linkage groups (LG1-LG10) spanning 710.48 cM, with an average genomic coverage of 91.39% and an average distance between markers of 2.62 cM. Average marker saturation was 27.7 per linkage group, ranging between 19 (LG9) and 36 markers (LG3). Using this map we identified 12 quantitative trait loci (QTLs) and 5 potential QTLs in the F1 outcross population of 236 full-sib Pacific oysters for four growth-related morphometric measures, including individual wet live weight, shell length, shell width and shell depth measured at four post-fertilization time points: plant-out (average age of 140 days), first year interim (average age of 358 days), second year interim (average age of 644 days) and harvest (average age of 950 days). Mapped QTLs and potential QTLs accounted for an average of 11.2% of the total phenotypic variation and ranged between 2.1 and 33.1%. Although QTL or potential QTL were mapped to all Pacific oyster linkage groups with the exception of LG2, LG8 and LG9, three groups (LG4, LG10 and LG5) were associated with three or more QTL or potential QTL. We conclude that alleles accounting for a significant proportion of the total phenotypic variation for morphometric measures that influence harvest yield remain segregating within the broodstock of West Coast Pacific oyster selective breeding programs. Title: Identification of optimal broodstock for Pacific Northwest oysters Author: Stick, David A. The United States Pacific Northwest is well known for its shellfish farming. Historically, commercial harvests were dominated by the native Olympia oyster, Ostrea lurida, but over-exploitation, habitat degradation, and competition and predation by non-native species has drastically depleted their densities and extirpated many local populations. As a result, shellfish aquaculture production has shifted to the introduced Pacific oyster, Crassostrea gigas. An underlying objective of this dissertation is the use of molecular genetics to improve our ability to accurately identifying optimal oyster broodstock for either restoration of Olympia oysters or farming of Pacific oysters. The ecological benefits provided by oysters as well as the Olympia oyster's historical significance, has motivated numerous restoration/supplementation efforts but these efforts are proceeding without a clear understanding of the genetic structure among extant populations, which could be substantial as a consequence of limited dispersal, local adaptation and/or anthropogenic impacts. To facilitate this understanding, we isolated and characterized 19 polymorphic microsatellites and used 8 of these to study the genetic structure of 2,712 individuals collected from 25 remnant Olympia oyster populations between the northern tip of Vancouver Island BC and Elkhorn Slough CA. Gene flow among geographically separated extant Olympia oyster populations is surprisingly limited for a marine invertebrate species whose free-swimming larvae are capable of planktonic dispersal as long as favorable water conditions exist. We found a significant correlation between geographic and genetic distances supporting the premise that coastal populations are isolated by distance. Genetic structure among remnant populations was not limited to broad geographic regions but was also present at sub-regional scales in both Puget Sound WA and San Francisco Bay CA. Until it can be determined whether genetically differentiated O. lurida populations are locally adapted, restoration projects and resource managers should be cautious of random mixing or transplantation of stocks where gene flow is restricted. As we transition from our Olympia oyster population analysis to our Pacific oyster quantitative analysis, we recognize that traditional quantitative trait locus (QTL) mapping strategies use crosses among inbred lines to create segregating populations. Unfortunately, even low levels of inbreeding in the Pacific oyster (Crassostrea gigas) can substantially depress economically important quantitative traits such as yield and survival, potentially complicating subsequent QTL analyses. To circumvent this problem, we constructed an integrated linkage map for Pacific oysters, consisting of 65 microsatellite (18 of which were previously unmapped) and 212 AFLP markers using a full-sib cross between phenotypically differentiated outbred families. We identified 10 linkage groups (LG1-LG10) spanning 710.48 cM, with an average genomic coverage of 91.39% and an average distance between markers of 2.62 cM. Average marker saturation was 27.7 per linkage group, ranging between 19 (LG9) and 36 markers (LG3). Using this map we identified 12 quantitative trait loci (QTLs) and 5 potential QTLs in the F1 outcross population of 236 full-sib Pacific oysters for four growth-related morphometric measures, including individual wet live weight, shell length, shell width and shell depth measured at four post-fertilization time points: plant-out (average age of 140 days), first year interim (average age of 358 days), second year interim (average age of 644 days) and harvest (average age of 950 days). Mapped QTLs and potential QTLs accounted for an average of 11.2% of the total phenotypic variation and ranged between 2.1 and 33.1%. Although QTL or potential QTL were mapped to all Pacific oyster linkage groups with the exception of LG2, LG8 and LG9, three groups (LG4, LG10 and LG5) were associated with three or more QTL or potential QTL. We conclude that alleles accounting for a significant proportion of the total phenotypic variation for morphometric measures that influence harvest yield remain segregating within the broodstock of West Coast Pacific oyster selective breeding programs. Close

• 78. [Article] Oregon Chub Investigations, Progress Report 2001

  Abstract -- Populations of Oregon chub Oregonichthys crameri, endemic to the Willamette Valley, have been drastically reduced. Factors in the decline of this fish include changes in flow regimes and habitat ...

  Citation × Citation Citation Abstract Copy Title: Oregon Chub Investigations, Progress Report 2001 Abstract -- Populations of Oregon chub Oregonichthys crameri, endemic to the Willamette Valley, have been drastically reduced. Factors in the decline of this fish include changes in flow regimes and habitat characteristics resulting from the construction of flood control dams, revetments, channelization, diking, and the drainage of wetlands. The Oregon chub is further threatened by predation and competition by non-native species such as largemouth bass Micropterus salmoides, small mouth bass M. dolomieui, crappies Pomoxis sp., sunfishes Lepomis sp., bullheads Ameiurus sp., and western mosquitofish Gambusia affinis. We surveyed in the Willamette River drainage in April-October 2000 to quantify existing Oregon chub populations, search for unknown populations, evaluate potential introduction sites, and monitor introduced populations. We sampled a total of 77 sites in 2000. We collected Oregon chub for the first time from Barnard Slough in the Middle Fork Willamette drainage. Oregon chub were last collected from this location in 1983 (Bond 1984). Thirty-one of the 77 sites were new sites that were sampled for the first time in 2000. Forty-six sites, sampled in 1991-1999, were revisited. Three sites were sampled twice. We confirmed the continued existence of Oregon chub at 20 locations. These include naturally occurring populations in the Santiam drainage (Geren Island, Santiam Conservation Easement, Gray Slough, Santiam 1-5 backwaters, Pioneer Park backwater, Santiam Public Works Pond), Mid-Willamette drainage (Finley Gray Creek Swamp) and Middle Fork Willamette drainage (Dexter Reservoir Alcoves, East Fork Minnow Creek Pond, Shady Dell Pond, Buckhead Creek, Oakridge Slough, Elijah Bristow State Park, Rattlesnake Creek, and Hospital Pond) and introduced populations in the Middle Fork Willamette (Wicopee Pond, Fall Creek Spillway Ponds), Santiam (Foster Pullout Pond), and Mid-Willamette drainages (Dunn Wetland, Finley Display Pond). Oregon chub were not found at several locations (Jasper Park Slough, Wallace Slough, East Ferrin Pond, Dexter East Alcove, Hospital lmpoundment Pond, Logan Slough, Green's Bridge Backwater, Camas Swale) where they were collected on at least one occasion between 1991-1999 (Scheerer et. al. 1992; 1993; 1994; 1995; 1996; 1998; 1999; 2000; Scheerer and Jones 1997). Non-native fish were common in off-channel habitats that were surveyed in the Willamette River drainage. Non-native fish were collected from 23 of the 31 new sites sampled in 1999 (74%); no fish were collected at three locations (10%). Western mosquitofish and centrarchids (largemouth bass and bluegill) were the most common non-native fish collected. Oregon chub were introduced into Menear's Bend Pond in the Santiam River drainage in the October 2000. Additional Oregon chub were introduced into Foster Pullout Pond in October 2000, to supplement the 85 fish introduced in 1999. In the summer of 2000, a habitat enhancement project creating new habitat to benefit Oregon chub was completed in the Long Tom drainage (Mid-Willamette River). Seven potential Oregon chub reintroduction sites were monitored and evaluated. These included four sites in the Mid-Willamette River drainage (Finley National Wildlife Refuge Beaver and Cattail Ponds, Ankeny National Wildlife Refuge Dunlin-Woodduck Pond, Long Tom Ranch Pond), one site in the Santiam River drainage (Menear's Bend Pond), one site in the McKenzie River drainage (Russell Pond), and one site in the Coast Fork Willamette drainage (Layng Pond). Estimates of abundance were obtained for naturally occurring populations of Oregon chub in East Fork Minnow Creek Pond, Shady Dell Pond, Elijah Bristow State Park Sloughs, Hospital Pond, Dexter Reservoir Alcoves, Buckhead Creek, Oakridge Slough, Santiam Conservation Easement Sloughs, Geren Island Ponds, and Finley Gray Creek Swamp. Five of these populations showed an increase in abundance in 2000 (East Fork Minnow Creek Pond, Shady Dell Pond, Middle Buckhead Creek, Dexter Reservoir Alcoves, Finley Gray Creek Swamp). Four populations decreased in abundance (or remain depressed) in 2000 (Geren Island, Santiam Conservation Easement, Elijah Bristow Sloughs, Oakridge Slough) (Table 1 ). Abundance estimates for introduced populations of Oregon chub were also obtained. The Oregon chub population in East Ferrin Pond declined from 7,200 fish in 1997 to O fish in 2000, and is presumed extinct. The Oregon chub population in the Fall Creek Spillway Pond totaled 5,030 fish in 2000, compared to 6,300 fish in 1999. The Oregon chub population in Wicopee Pond expanded dramatically from ~50 fish in 1999 to 4,580 fish in 2000. The Oregon chub population in the Dunn Wetland Ponds increased from 4,860 fish in 1999 to 14,090 fish in 2000. The Oregon chub population in Finley Display Pond increased from 360 fish in 1999 to 1,750 fish in 2000. Three of the four largest populations in 2000 were introduced populations. The Middle Fork Willamette River drainage supported the largest number of Oregon chub populations (n=12), followed by the Santiam drainage (n=B), and the Mid-Willamette drainage (n=5). The most abundant Oregon chub populations were found in the Middle Fork Willamette and Mid-Willamette drainages. The Oregon Chub Recovery Plan (U .S. Fish and Wildlife Service 1998) set a recovery goal for downlisting the species to "threatened" and for delisting the species. The criteria for downlisting the species was to establish and manage ten populations of at least 500 adult fish. All populations must exhibit a stable or increasing trend for five years. At least three populations must be located in each of the three sub-basins (Middle Fork Willamette River, Santiam River, Mid-Willamette River tributaries). In 2000, there were 11 populations totaling 500 or more individuals and six of these populations exhibited a stable or increasing trend for the past five years (Table 1 ). Five of these six populations were located in the Middle Fork Willamette drainage. In summary, Oregon chub remain at risk due to their limited distribution compared with their historic geographic range in the Willamette Valley, the loss of suitable habitat and the continued threats posed by the proliferation of non-native fishes, illegal water withdrawals, unauthorized fill and removal operations, and potential chemical spills or careless pesticide applications. Title: Oregon Chub Investigations, Progress Report 2001 Abstract -- Populations of Oregon chub Oregonichthys crameri, endemic to the Willamette Valley, have been drastically reduced. Factors in the decline of this fish include changes in flow regimes and habitat characteristics resulting from the construction of flood control dams, revetments, channelization, diking, and the drainage of wetlands. The Oregon chub is further threatened by predation and competition by non-native species such as largemouth bass Micropterus salmoides, small mouth bass M. dolomieui, crappies Pomoxis sp., sunfishes Lepomis sp., bullheads Ameiurus sp., and western mosquitofish Gambusia affinis. We surveyed in the Willamette River drainage in April-October 2000 to quantify existing Oregon chub populations, search for unknown populations, evaluate potential introduction sites, and monitor introduced populations. We sampled a total of 77 sites in 2000. We collected Oregon chub for the first time from Barnard Slough in the Middle Fork Willamette drainage. Oregon chub were last collected from this location in 1983 (Bond 1984). Thirty-one of the 77 sites were new sites that were sampled for the first time in 2000. Forty-six sites, sampled in 1991-1999, were revisited. Three sites were sampled twice. We confirmed the continued existence of Oregon chub at 20 locations. These include naturally occurring populations in the Santiam drainage (Geren Island, Santiam Conservation Easement, Gray Slough, Santiam 1-5 backwaters, Pioneer Park backwater, Santiam Public Works Pond), Mid-Willamette drainage (Finley Gray Creek Swamp) and Middle Fork Willamette drainage (Dexter Reservoir Alcoves, East Fork Minnow Creek Pond, Shady Dell Pond, Buckhead Creek, Oakridge Slough, Elijah Bristow State Park, Rattlesnake Creek, and Hospital Pond) and introduced populations in the Middle Fork Willamette (Wicopee Pond, Fall Creek Spillway Ponds), Santiam (Foster Pullout Pond), and Mid-Willamette drainages (Dunn Wetland, Finley Display Pond). Oregon chub were not found at several locations (Jasper Park Slough, Wallace Slough, East Ferrin Pond, Dexter East Alcove, Hospital lmpoundment Pond, Logan Slough, Green's Bridge Backwater, Camas Swale) where they were collected on at least one occasion between 1991-1999 (Scheerer et. al. 1992; 1993; 1994; 1995; 1996; 1998; 1999; 2000; Scheerer and Jones 1997). Non-native fish were common in off-channel habitats that were surveyed in the Willamette River drainage. Non-native fish were collected from 23 of the 31 new sites sampled in 1999 (74%); no fish were collected at three locations (10%). Western mosquitofish and centrarchids (largemouth bass and bluegill) were the most common non-native fish collected. Oregon chub were introduced into Menear's Bend Pond in the Santiam River drainage in the October 2000. Additional Oregon chub were introduced into Foster Pullout Pond in October 2000, to supplement the 85 fish introduced in 1999. In the summer of 2000, a habitat enhancement project creating new habitat to benefit Oregon chub was completed in the Long Tom drainage (Mid-Willamette River). Seven potential Oregon chub reintroduction sites were monitored and evaluated. These included four sites in the Mid-Willamette River drainage (Finley National Wildlife Refuge Beaver and Cattail Ponds, Ankeny National Wildlife Refuge Dunlin-Woodduck Pond, Long Tom Ranch Pond), one site in the Santiam River drainage (Menear's Bend Pond), one site in the McKenzie River drainage (Russell Pond), and one site in the Coast Fork Willamette drainage (Layng Pond). Estimates of abundance were obtained for naturally occurring populations of Oregon chub in East Fork Minnow Creek Pond, Shady Dell Pond, Elijah Bristow State Park Sloughs, Hospital Pond, Dexter Reservoir Alcoves, Buckhead Creek, Oakridge Slough, Santiam Conservation Easement Sloughs, Geren Island Ponds, and Finley Gray Creek Swamp. Five of these populations showed an increase in abundance in 2000 (East Fork Minnow Creek Pond, Shady Dell Pond, Middle Buckhead Creek, Dexter Reservoir Alcoves, Finley Gray Creek Swamp). Four populations decreased in abundance (or remain depressed) in 2000 (Geren Island, Santiam Conservation Easement, Elijah Bristow Sloughs, Oakridge Slough) (Table 1 ). Abundance estimates for introduced populations of Oregon chub were also obtained. The Oregon chub population in East Ferrin Pond declined from 7,200 fish in 1997 to O fish in 2000, and is presumed extinct. The Oregon chub population in the Fall Creek Spillway Pond totaled 5,030 fish in 2000, compared to 6,300 fish in 1999. The Oregon chub population in Wicopee Pond expanded dramatically from ~50 fish in 1999 to 4,580 fish in 2000. The Oregon chub population in the Dunn Wetland Ponds increased from 4,860 fish in 1999 to 14,090 fish in 2000. The Oregon chub population in Finley Display Pond increased from 360 fish in 1999 to 1,750 fish in 2000. Three of the four largest populations in 2000 were introduced populations. The Middle Fork Willamette River drainage supported the largest number of Oregon chub populations (n=12), followed by the Santiam drainage (n=B), and the Mid-Willamette drainage (n=5). The most abundant Oregon chub populations were found in the Middle Fork Willamette and Mid-Willamette drainages. The Oregon Chub Recovery Plan (U .S. Fish and Wildlife Service 1998) set a recovery goal for downlisting the species to "threatened" and for delisting the species. The criteria for downlisting the species was to establish and manage ten populations of at least 500 adult fish. All populations must exhibit a stable or increasing trend for five years. At least three populations must be located in each of the three sub-basins (Middle Fork Willamette River, Santiam River, Mid-Willamette River tributaries). In 2000, there were 11 populations totaling 500 or more individuals and six of these populations exhibited a stable or increasing trend for the past five years (Table 1 ). Five of these six populations were located in the Middle Fork Willamette drainage. In summary, Oregon chub remain at risk due to their limited distribution compared with their historic geographic range in the Willamette Valley, the loss of suitable habitat and the continued threats posed by the proliferation of non-native fishes, illegal water withdrawals, unauthorized fill and removal operations, and potential chemical spills or careless pesticide applications. Close

• 79. [Article] An Integrated Aquatic Vegetation Management Plan for Blue Lake, Fairview, Oregon

  Blue Lake, located in Fairview, is on the 1998 Oregon Department of Environmental Quality (ODEQ) 303(d) list of water quality impaired water bodies for violating the upper pH standard (8.5) and supporting ...

  Citation × Citation Citation Abstract Copy Title: An Integrated Aquatic Vegetation Management Plan for Blue Lake, Fairview, Oregon Author: Pfauth, Mary, Sytsma, Mark Year: 2004 Blue Lake, located in Fairview, is on the 1998 Oregon Department of Environmental Quality (ODEQ) 303(d) list of water quality impaired water bodies for violating the upper pH standard (8.5) and supporting abundant aquatic weeds and alge. The lake is eutrophic and has high algal productivity, especially in mid to late summer. Curlyleaf pondweed, a non-native, invasive aquatic plant species, restricts access to and use of Blue Lake by humans. Human uses of the lake which have been impaired including boating, water skiing, fishing, and swimming. Development of the current Integrated Aquatic Vegetation Management Plan was driven by the need for an integrated, adaptive management strategy which would address not only the control and prevention of invasive, nuisance plants but also their interaction with algal productivity and water quality, especially pH. The overarching goal of the Blue Lake Integrated Vegetation Management Plan is to control nuisance aquatic vegetation. Title: An Integrated Aquatic Vegetation Management Plan for Blue Lake, Fairview, Oregon Author: Pfauth, Mary, Sytsma, Mark Year: 2004 Blue Lake, located in Fairview, is on the 1998 Oregon Department of Environmental Quality (ODEQ) 303(d) list of water quality impaired water bodies for violating the upper pH standard (8.5) and supporting abundant aquatic weeds and alge. The lake is eutrophic and has high algal productivity, especially in mid to late summer. Curlyleaf pondweed, a non-native, invasive aquatic plant species, restricts access to and use of Blue Lake by humans. Human uses of the lake which have been impaired including boating, water skiing, fishing, and swimming. Development of the current Integrated Aquatic Vegetation Management Plan was driven by the need for an integrated, adaptive management strategy which would address not only the control and prevention of invasive, nuisance plants but also their interaction with algal productivity and water quality, especially pH. The overarching goal of the Blue Lake Integrated Vegetation Management Plan is to control nuisance aquatic vegetation. Close

• 80. [Article] Drift Creek (Alsea River) restoration project decision memo

  3 pp. T13S, R11E, Sections 22, 23, 24. Captured February 14, 2008.

  Citation × Citation Citation Abstract Copy Title: Drift Creek (Alsea River) restoration project decision memo Author: South Zone Ranger District (Or.) Year: 2008, 2005 3 pp. T13S, R11E, Sections 22, 23, 24. Captured February 14, 2008. Title: Drift Creek (Alsea River) restoration project decision memo Author: South Zone Ranger District (Or.) Year: 2008, 2005 3 pp. T13S, R11E, Sections 22, 23, 24. Captured February 14, 2008. Close