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• 1. [Article] Invasive Species Management Plan for Oswego Lake

  This Invasive Species Management Plan defines an overarching strategy for the Lake Oswego Corporation (LOC) to mitigate threats from invasive species to Oswego Lake. Invasive species pose a direct risk ...

  Citation × Citation Citation Abstract Copy Title: Invasive Species Management Plan for Oswego Lake Author: Warren, Daniel Year: 2009 This Invasive Species Management Plan defines an overarching strategy for the Lake Oswego Corporation (LOC) to mitigate threats from invasive species to Oswego Lake. Invasive species pose a direct risk to recreational and aesthetic uses of the lake, critical LOC infrastructure, and ecological communities within the lake. The Plan is particularly concerned with two bivalve mollusks in the genus Dreissena: the zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena bugensis). These mussels grow in dense colonies that damage watercraft and underwater structures as well as displace native species. A recent scientific report found that an intense infestation of mussels in Oswego Lake is unlikely due to the water chemistry, but a low to moderate level of infestation is possible. Any level of infestation could be very serious and warrants proactive preventative measures and response plans should an invasion occur. In addition to the harmful mussels, this Plan identifies preventative and response measures for other species such as hydrilla (Hydrilla verticillata) that have the potential to harm Oswego Lake. Strategies outlined in this Plan are as follows: • Identification and prioritization of likely potential invasive species • Identification of vectors of establishment •Prevention strategies • Development of monitoring plans • Rapid response action plans and control measures if an invasion is detected Prevention is the top management priority for all invasive species as the cost and difficulty of controlling or eradicating an invasion increase significantly as an invasion spreads. This includes active measures to exclude species as well as the ongoing education and involvement of community members. Effective monitoring and rapid response action plans are the next priority to detect and eradicate an exotic species before it establishes and spreads. The integration of these strategies will help the LOC prevent significant deleterious effects from invasive species in Oswego Lake so that the basic operations of the LOC are facilitated and recreational and aesthetic opportunities are preserved. Title: Invasive Species Management Plan for Oswego Lake Author: Warren, Daniel Year: 2009 This Invasive Species Management Plan defines an overarching strategy for the Lake Oswego Corporation (LOC) to mitigate threats from invasive species to Oswego Lake. Invasive species pose a direct risk to recreational and aesthetic uses of the lake, critical LOC infrastructure, and ecological communities within the lake. The Plan is particularly concerned with two bivalve mollusks in the genus Dreissena: the zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena bugensis). These mussels grow in dense colonies that damage watercraft and underwater structures as well as displace native species. A recent scientific report found that an intense infestation of mussels in Oswego Lake is unlikely due to the water chemistry, but a low to moderate level of infestation is possible. Any level of infestation could be very serious and warrants proactive preventative measures and response plans should an invasion occur. In addition to the harmful mussels, this Plan identifies preventative and response measures for other species such as hydrilla (Hydrilla verticillata) that have the potential to harm Oswego Lake. Strategies outlined in this Plan are as follows: • Identification and prioritization of likely potential invasive species • Identification of vectors of establishment •Prevention strategies • Development of monitoring plans • Rapid response action plans and control measures if an invasion is detected Prevention is the top management priority for all invasive species as the cost and difficulty of controlling or eradicating an invasion increase significantly as an invasion spreads. This includes active measures to exclude species as well as the ongoing education and involvement of community members. Effective monitoring and rapid response action plans are the next priority to detect and eradicate an exotic species before it establishes and spreads. The integration of these strategies will help the LOC prevent significant deleterious effects from invasive species in Oswego Lake so that the basic operations of the LOC are facilitated and recreational and aesthetic opportunities are preserved. Close

• 2. [Article] Aquatic Invasive Species Surveys of Pacificorp’s North Umpqua River Impoundments

  Ten North Umpqua Hydroelectric Project impoundments were surveyed for aquatic invasive species during the summer of 2012. One non-native submersed aquatic vegetation species (Potamogeton crispus) and one ...

  Citation × Citation Citation Abstract Copy Title: Aquatic Invasive Species Surveys of Pacificorp’s North Umpqua River Impoundments Author: Miller, Rich, Sytsma, Mark D., Morgan, Vanessa Howard Year: 2013 Ten North Umpqua Hydroelectric Project impoundments were surveyed for aquatic invasive species during the summer of 2012. One non-native submersed aquatic vegetation species (Potamogeton crispus) and one non-native snail species (Radix auricularia) was detected. No crayfish or mussel veligers were collected and no non-native zooplankton species were encountered. Title: Aquatic Invasive Species Surveys of Pacificorp’s North Umpqua River Impoundments Author: Miller, Rich, Sytsma, Mark D., Morgan, Vanessa Howard Year: 2013 Ten North Umpqua Hydroelectric Project impoundments were surveyed for aquatic invasive species during the summer of 2012. One non-native submersed aquatic vegetation species (Potamogeton crispus) and one non-native snail species (Radix auricularia) was detected. No crayfish or mussel veligers were collected and no non-native zooplankton species were encountered. Close

• 3. [Article] An Investigation of Invasion: Boater Knowledge Concerning Aquatic Invasive Species and the Influence of the New Zealand Mud Snail on Benthic Food Webs

  Invasive species are second only to habitat loss as a leading cause of native species displacement and the management of invasive species costs hundreds of billions annually. Invasion is often conceptualized ...

  Citation × Citation Citation Abstract Copy Title: An Investigation of Invasion: Boater Knowledge Concerning Aquatic Invasive Species and the Influence of the New Zealand Mud Snail on Benthic Food Webs Author: Cimino, Samuel Anthony Year: 2016 Invasive species are second only to habitat loss as a leading cause of native species displacement and the management of invasive species costs hundreds of billions annually. Invasion is often conceptualized as a series of stages (Transport, Introduction, Establishment, and Spread), which encourages ecologists to isolate factors that might enable a species to pass from one stage to another and therefore guide prevention or impact management. This thesis addresses each stage of invasion and attempts to determine where management might succeed in preventing invasion or minimizing impacts. The transport and introduction of aquatic invasive species (AIS) was analyzed by conducting a three tier human subjects survey at Tenmile Lake, Oregon over a two year period in which a public boat wash station was built and installed. Assessing boater knowledge of AIS and understanding proper boat cleaning procedure is useful in determining the threat of transport and introduction as overland boater movements is a major vector of AIS. The comparison between pre- and post- boat wash surveys indicate that there is a disconnect between what boaters say they will do and how they actually behave. While 75.9% of boaters from the pre-survey claimed they would use a boat wash station at Tenmile Lake, only 38.5% of post-survey boaters were observed using the station. Furthermore, the surveys identified knowledge gaps of boaters' awareness of AIS. More than 20.0% of boaters surveyed could not verbally name any AIS. To better understand the establishment and spread stages of invasion, I examined the influence of a specific AIS, the New Zealand mud snail (Potamopyrgus antipodarum; NZMS), on benthic food webs throughout three very different aquatic ecosystems (lakes, rivers, and estuaries). Samples of benthic lake, river, and estuarine invertebrates were collected, identified, and counted, and stable isotope analyses (SIA) were conducted on several components of the food web. NZMS densities were found to be dynamic, with population densities fluctuating over time and between locations. A significant negative relationship between NZMS density and community diversity across all ecosystems was found. However, the densities of specific feeding groups had varying positive (omnivores) and negative (herbivores) correlations with NZMS densities. Furthermore, SIA indicated that NZMS don't appear to be competing with native macroinvertebrates for the same food source. NZMS were found to have different influences on each invaded ecosystem, thus management of this particular AIS is difficult once established and spreading. The results of this thesis suggest that prevention of the transport and introduction of NZMS needs to be the focus for future management. Preventative management should include public outreach regarding AIS and proper boat cleaning procedure, and management should also emphasize the need for regional policies and regulations on the transport of AIS rather than site or state specific policies and regulations. Title: An Investigation of Invasion: Boater Knowledge Concerning Aquatic Invasive Species and the Influence of the New Zealand Mud Snail on Benthic Food Webs Author: Cimino, Samuel Anthony Year: 2016 Invasive species are second only to habitat loss as a leading cause of native species displacement and the management of invasive species costs hundreds of billions annually. Invasion is often conceptualized as a series of stages (Transport, Introduction, Establishment, and Spread), which encourages ecologists to isolate factors that might enable a species to pass from one stage to another and therefore guide prevention or impact management. This thesis addresses each stage of invasion and attempts to determine where management might succeed in preventing invasion or minimizing impacts. The transport and introduction of aquatic invasive species (AIS) was analyzed by conducting a three tier human subjects survey at Tenmile Lake, Oregon over a two year period in which a public boat wash station was built and installed. Assessing boater knowledge of AIS and understanding proper boat cleaning procedure is useful in determining the threat of transport and introduction as overland boater movements is a major vector of AIS. The comparison between pre- and post- boat wash surveys indicate that there is a disconnect between what boaters say they will do and how they actually behave. While 75.9% of boaters from the pre-survey claimed they would use a boat wash station at Tenmile Lake, only 38.5% of post-survey boaters were observed using the station. Furthermore, the surveys identified knowledge gaps of boaters' awareness of AIS. More than 20.0% of boaters surveyed could not verbally name any AIS. To better understand the establishment and spread stages of invasion, I examined the influence of a specific AIS, the New Zealand mud snail (Potamopyrgus antipodarum; NZMS), on benthic food webs throughout three very different aquatic ecosystems (lakes, rivers, and estuaries). Samples of benthic lake, river, and estuarine invertebrates were collected, identified, and counted, and stable isotope analyses (SIA) were conducted on several components of the food web. NZMS densities were found to be dynamic, with population densities fluctuating over time and between locations. A significant negative relationship between NZMS density and community diversity across all ecosystems was found. However, the densities of specific feeding groups had varying positive (omnivores) and negative (herbivores) correlations with NZMS densities. Furthermore, SIA indicated that NZMS don't appear to be competing with native macroinvertebrates for the same food source. NZMS were found to have different influences on each invaded ecosystem, thus management of this particular AIS is difficult once established and spreading. The results of this thesis suggest that prevention of the transport and introduction of NZMS needs to be the focus for future management. Preventative management should include public outreach regarding AIS and proper boat cleaning procedure, and management should also emphasize the need for regional policies and regulations on the transport of AIS rather than site or state specific policies and regulations. Close

• 4. [Article] Complex Interactions Between Regional Dispersal of Native Taxa and an Invasive Species

  In the event of an environmental disturbance, dispersal of native taxa may provide species and genetic diversity to ecosystems, increasing the likelihood that there will be species and genotypes present ...

  Citation × Citation Citation Abstract Copy Title: Complex Interactions Between Regional Dispersal of Native Taxa and an Invasive Species Author: Strecker, Angela L., Arnott, Shelley E. Year: 2010 In the event of an environmental disturbance, dispersal of native taxa may provide species and genetic diversity to ecosystems, increasing the likelihood that there will be species and genotypes present that are less vulnerable to the disturbance. This may allow communities to maintain functioning during a disturbance and may be particularly important when the perturbation is novel to the system, such as the establishment of an invasive species. We examined how dispersal of native species may influence crustacean zooplankton communities in freshwater lakes invaded by the invertebrate predator, Bythotrephes longimanus. Using large enclosures, we experimentally tested the effect of dispersal on zooplankton community abundance, richness, and composition in (1) a community invaded by Bythotrephes, (2) the same community with the invader removed, and (3) a community that was never invaded. Dispersal increased zooplankton community abundance and richness; however, these effects were usually only significant in the invader-removed treatment. Dispersal tended to make the invader-removed communities more similar to never-invaded communities in abundance, richness, and composition. Dispersal had little effect on zooplankton abundance in the invaded community; however, richness significantly increased, and the community composition changed to resemble a never-invaded community by the end of the experiment. Our results have implications for understanding the role of dispersal during transitory states in communities. Dispersal of native taxa may be particularly important during the period between the arrival and broad-scale establishment of Bythotrephes, as dispersal through space or time (i.e., from resting eggs) may rapidly increase zooplankton abundance when the invader is absent or in low abundances. Overall, our results suggest that communities with strong local predatory and competitive interactions may be closed to immigration from colonists, but that invasive species may alter the conditions under which species can establish. These results have implications for the interaction of native and invasive species across broad spatial scales, as regional dispersal of native taxa may forestall the local extirpation of native species. In particular, transient phases that result from variable persistence of invaders within habitats or across a region may permit native colonists to successfully establish, and thus increase local and regional resistance to future disturbance. Title: Complex Interactions Between Regional Dispersal of Native Taxa and an Invasive Species Author: Strecker, Angela L., Arnott, Shelley E. Year: 2010 In the event of an environmental disturbance, dispersal of native taxa may provide species and genetic diversity to ecosystems, increasing the likelihood that there will be species and genotypes present that are less vulnerable to the disturbance. This may allow communities to maintain functioning during a disturbance and may be particularly important when the perturbation is novel to the system, such as the establishment of an invasive species. We examined how dispersal of native species may influence crustacean zooplankton communities in freshwater lakes invaded by the invertebrate predator, Bythotrephes longimanus. Using large enclosures, we experimentally tested the effect of dispersal on zooplankton community abundance, richness, and composition in (1) a community invaded by Bythotrephes, (2) the same community with the invader removed, and (3) a community that was never invaded. Dispersal increased zooplankton community abundance and richness; however, these effects were usually only significant in the invader-removed treatment. Dispersal tended to make the invader-removed communities more similar to never-invaded communities in abundance, richness, and composition. Dispersal had little effect on zooplankton abundance in the invaded community; however, richness significantly increased, and the community composition changed to resemble a never-invaded community by the end of the experiment. Our results have implications for understanding the role of dispersal during transitory states in communities. Dispersal of native taxa may be particularly important during the period between the arrival and broad-scale establishment of Bythotrephes, as dispersal through space or time (i.e., from resting eggs) may rapidly increase zooplankton abundance when the invader is absent or in low abundances. Overall, our results suggest that communities with strong local predatory and competitive interactions may be closed to immigration from colonists, but that invasive species may alter the conditions under which species can establish. These results have implications for the interaction of native and invasive species across broad spatial scales, as regional dispersal of native taxa may forestall the local extirpation of native species. In particular, transient phases that result from variable persistence of invaders within habitats or across a region may permit native colonists to successfully establish, and thus increase local and regional resistance to future disturbance. Close

• 5. [Article] Evaluating Simplistic Methods to Understand Current Distributions and Forecast Distribution Changes Under Climate Change Scenarios: An Example With Coypu (Myocastor coypus)

  Invasive species provide a unique opportunity to evaluate factors controlling biogeographic distributions; we can consider introduction success as an experiment testing suitability of environmental conditions. ...

  Citation × Citation Citation Abstract Copy Title: Evaluating Simplistic Methods to Understand Current Distributions and Forecast Distribution Changes Under Climate Change Scenarios: An Example With Coypu (Myocastor coypus) Author: Jarnevich, Catherine S., Young, Nicholas E., Sheffels, Trevor R., Carter, Jacoby, Sytsma, Mark D., Talbert, Colin Year: 2017 Invasive species provide a unique opportunity to evaluate factors controlling biogeographic distributions; we can consider introduction success as an experiment testing suitability of environmental conditions. Predicting potential distributions of spreading species is not easy, and forecasting potential distributions with changing climate is even more difficult. Using the globally invasive coypu (Myocastor coypus [Molina, 1782]), we evaluate and compare the utility of a simplistic ecophysiological based model and a correlative model to predict current and future distribution. The ecophysiological model was based on winter temperature relationships with nutria survival. We developed correlative statistical models using the Software for Assisted Habitat Modeling and biologically relevant climate data with a global extent. We applied the ecophysiological based model to several global circulation model (GCM) predictions for mid-century. We used global coypu introduction data to evaluate these models and to explore a hypothesized physiological limitation, finding general agreement with known coypu distribution locally and globally and support for an upper thermal tolerance threshold. Global circulation model based model results showed variability in coypu predicted distribution among GCMs, but had general agreement of increasing suitable area in the USA. Our methods highlighted the dynamic nature of the edges of the coypu distribution due to climate non-equilibrium, and uncertainty associated with forecasting future distributions. Areas deemed suitable habitat, especially those on the edge of the current known range, could be used for early detection of the spread of coypu populations for management purposes. Combining approaches can be beneficial to predicting potential distributions of invasive species now and in the future and in exploring hypotheses of factors controlling distributions. Title: Evaluating Simplistic Methods to Understand Current Distributions and Forecast Distribution Changes Under Climate Change Scenarios: An Example With Coypu (Myocastor coypus) Author: Jarnevich, Catherine S., Young, Nicholas E., Sheffels, Trevor R., Carter, Jacoby, Sytsma, Mark D., Talbert, Colin Year: 2017 Invasive species provide a unique opportunity to evaluate factors controlling biogeographic distributions; we can consider introduction success as an experiment testing suitability of environmental conditions. Predicting potential distributions of spreading species is not easy, and forecasting potential distributions with changing climate is even more difficult. Using the globally invasive coypu (Myocastor coypus [Molina, 1782]), we evaluate and compare the utility of a simplistic ecophysiological based model and a correlative model to predict current and future distribution. The ecophysiological model was based on winter temperature relationships with nutria survival. We developed correlative statistical models using the Software for Assisted Habitat Modeling and biologically relevant climate data with a global extent. We applied the ecophysiological based model to several global circulation model (GCM) predictions for mid-century. We used global coypu introduction data to evaluate these models and to explore a hypothesized physiological limitation, finding general agreement with known coypu distribution locally and globally and support for an upper thermal tolerance threshold. Global circulation model based model results showed variability in coypu predicted distribution among GCMs, but had general agreement of increasing suitable area in the USA. Our methods highlighted the dynamic nature of the edges of the coypu distribution due to climate non-equilibrium, and uncertainty associated with forecasting future distributions. Areas deemed suitable habitat, especially those on the edge of the current known range, could be used for early detection of the spread of coypu populations for management purposes. Combining approaches can be beneficial to predicting potential distributions of invasive species now and in the future and in exploring hypotheses of factors controlling distributions. Close

• 6. [Article] Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA

  Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch ...

  Citation × Citation Citation Abstract Copy Title: Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA Author: Christy, John A. Year: 2013 Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch associations are being infilled by a combination of plant succession and invasive species. Repeat photography using aerial and ground-based imagery is recommended as a way to gauge the rate of change in dune communities. Prescribed fire is recommended to monitor rejuvenation effects on two shore pine woodland associations that are most at risk of infilling. Vegetation mapping based on remote sensing will enable more accurate assessment of vegetation features, and facilitate modeling of management scenarios and effects of seal level rise, earthquakes, and tsunamis. Title: Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA Author: Christy, John A. Year: 2013 Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch associations are being infilled by a combination of plant succession and invasive species. Repeat photography using aerial and ground-based imagery is recommended as a way to gauge the rate of change in dune communities. Prescribed fire is recommended to monitor rejuvenation effects on two shore pine woodland associations that are most at risk of infilling. Vegetation mapping based on remote sensing will enable more accurate assessment of vegetation features, and facilitate modeling of management scenarios and effects of seal level rise, earthquakes, and tsunamis. Close

• 7. [Article] Impact of Bythotrephes Invasion on Zooplankton Communities in Acid-Damaged and Recovered Lakes on the Boreal Shield

  Invasive species introductions into freshwater ecosystems have had a multitude of effects on aquatic communities. Few studies, however, have directly compared the impact of an invader on communities with ...

  Citation × Citation Citation Abstract Copy Title: Impact of Bythotrephes Invasion on Zooplankton Communities in Acid-Damaged and Recovered Lakes on the Boreal Shield Author: Strecker, Angela L., Arnott, Shelley E. Year: 2005 Invasive species introductions into freshwater ecosystems have had a multitude of effects on aquatic communities. Few studies, however, have directly compared the impact of an invader on communities with contrasting structure. Historically high levels and subsequent reductions of acid deposition have produced landscapes of lakes of varying acidity and zooplankton communitystructure. We conducted a 30-day enclosure experiment in Killarney Provincial Park, Ontario, Canada, to test the effects ofBythotrephes longimanus, an invasive invertebrate predator, on two contrasting zooplankton communities at different stages of recovery from acidification: recovered and acid damaged. Bythotrephes significantly decreased zooplankton biomass and abundance in both communities but had a greater negative effect on the abundance of zooplankton in the recovered community.Bythotrephes reduced species diversity of the recovered zooplankton community but not of the acid-damaged community. Species richness of both community types was unaffected by Bythotrephes predation. The effect of Bythotrephes on small cladocerans, a preferred prey type, differed between the community types and appeared to be related to density-dependent predation byBythotrephes. Both community- and species-level results suggest that recovered and acid-damaged zooplankton assemblages may be negatively affected by an invasion of Bythotrephes but that the specific response is dependent on the original community structure. Title: Impact of Bythotrephes Invasion on Zooplankton Communities in Acid-Damaged and Recovered Lakes on the Boreal Shield Author: Strecker, Angela L., Arnott, Shelley E. Year: 2005 Invasive species introductions into freshwater ecosystems have had a multitude of effects on aquatic communities. Few studies, however, have directly compared the impact of an invader on communities with contrasting structure. Historically high levels and subsequent reductions of acid deposition have produced landscapes of lakes of varying acidity and zooplankton communitystructure. We conducted a 30-day enclosure experiment in Killarney Provincial Park, Ontario, Canada, to test the effects ofBythotrephes longimanus, an invasive invertebrate predator, on two contrasting zooplankton communities at different stages of recovery from acidification: recovered and acid damaged. Bythotrephes significantly decreased zooplankton biomass and abundance in both communities but had a greater negative effect on the abundance of zooplankton in the recovered community.Bythotrephes reduced species diversity of the recovered zooplankton community but not of the acid-damaged community. Species richness of both community types was unaffected by Bythotrephes predation. The effect of Bythotrephes on small cladocerans, a preferred prey type, differed between the community types and appeared to be related to density-dependent predation byBythotrephes. Both community- and species-level results suggest that recovered and acid-damaged zooplankton assemblages may be negatively affected by an invasion of Bythotrephes but that the specific response is dependent on the original community structure. Close

• 8. [Article] Variation in Tussock Architecture of the Invasive Cordgrass Spartina Densiflora along the Pacific Coast of North America

  Some introduced species spread rapidly beyond their native range and into novel habitats mediated by a high degree of phenotypic plasticity and/or rapid evolutionary responses. In this context, clonality ...

  Citation × Citation Citation Abstract Copy Title: Variation in Tussock Architecture of the Invasive Cordgrass Spartina Densiflora along the Pacific Coast of North America Author: Castillo, Jesus M., Grewall, Brenda J., Pickart, Andrea, Figueroa, Enrique, Sytsma, Mark D. Year: 2016 Some introduced species spread rapidly beyond their native range and into novel habitats mediated by a high degree of phenotypic plasticity and/or rapid evolutionary responses. In this context, clonality has been described as a significant factor contributing to invasiveness. We studied the abiotic environment and the responses of different tussock architecture traits of the invasive cordgrass Spartina densiflora Brongn. (Poaceae). A common garden experiment and field studies of S. densiflora in salt marshes across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provided a model system for an integrated study of the potential mechanisms underlying the response of invasive S. densiflora populations to changes in environmental conditions. Our results showed that S. densiflora is able to adjust to widely variable climate (specifically, air temperature and the duration of the growing season) and sediment conditions (specifically, texture and hypoxia) through phenotypical plastic key functional tussock traits (e.g. shoot density, height, above- and below-ground biomass allocation patterns). Root biomass increased in coarser sediments in contrast to rhizomes, which were more abundant in finer sediments. Above-ground biomass and leaf area index increased mainly with air temperature during summer, and more robust (taller and wider) shoots were associated with more oxygenated sediments. In view of our results, S. densifloraappears to be a halophyte with a high degree of phenotypic plasticity that would enable it to respond successfully to changes in the abiotic conditions of salt marshes driven by global climate change, such as increasing salinity and temperatures. Title: Variation in Tussock Architecture of the Invasive Cordgrass Spartina Densiflora along the Pacific Coast of North America Author: Castillo, Jesus M., Grewall, Brenda J., Pickart, Andrea, Figueroa, Enrique, Sytsma, Mark D. Year: 2016 Some introduced species spread rapidly beyond their native range and into novel habitats mediated by a high degree of phenotypic plasticity and/or rapid evolutionary responses. In this context, clonality has been described as a significant factor contributing to invasiveness. We studied the abiotic environment and the responses of different tussock architecture traits of the invasive cordgrass Spartina densiflora Brongn. (Poaceae). A common garden experiment and field studies of S. densiflora in salt marshes across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provided a model system for an integrated study of the potential mechanisms underlying the response of invasive S. densiflora populations to changes in environmental conditions. Our results showed that S. densiflora is able to adjust to widely variable climate (specifically, air temperature and the duration of the growing season) and sediment conditions (specifically, texture and hypoxia) through phenotypical plastic key functional tussock traits (e.g. shoot density, height, above- and below-ground biomass allocation patterns). Root biomass increased in coarser sediments in contrast to rhizomes, which were more abundant in finer sediments. Above-ground biomass and leaf area index increased mainly with air temperature during summer, and more robust (taller and wider) shoots were associated with more oxygenated sediments. In view of our results, S. densifloraappears to be a halophyte with a high degree of phenotypic plasticity that would enable it to respond successfully to changes in the abiotic conditions of salt marshes driven by global climate change, such as increasing salinity and temperatures. Close

• 9. [Article] Non-native Mangroves of Moloka'i, Hawai'i: A Socio-ecological Analysis

  Invasive species are recognized as a leading threat to ecosystems and their management is expensive, time consuming, and labor intensive. Therefore, it is important to review both benefits and detriments ...

  Citation × Citation Citation Abstract Copy Title: Non-native Mangroves of Moloka'i, Hawai'i: A Socio-ecological Analysis Author: Lewis, Casey Year: 2017 Invasive species are recognized as a leading threat to ecosystems and their management is expensive, time consuming, and labor intensive. Therefore, it is important to review both benefits and detriments of the species to inform appropriate management decisions. Red mangrove was introduced to Moloka'i, Hawaii in 1902 to mitigate the effects of soil erosion and has since spread along the coast and to adjacent islands creating novel habitat. This study assessed both biological services and social attitudes towards Moloka'i's non-native mangroves to provide a comprehensive evaluation of the species. Zooplankton community structure was examined in mangrove and non-mangrove sites and found to be different depending on the amount of mangroves present. Surveys of Moloka'i residents revealed no majority attitude towards mangroves nor support for complete eradication but residents were highly supportive of active management. Approaching other novel ecosystems created by established non-native species from a socio-ecological view may become more crucial as changes in climate, demographics, and environmental conditions further complicate effects. In our globalized world, non-native species introductions will continue to have both positive and negative effects that vary over time. Therefore, assessment of both social and ecological perspectives may lead to more effective management with greater community support. Title: Non-native Mangroves of Moloka'i, Hawai'i: A Socio-ecological Analysis Author: Lewis, Casey Year: 2017 Invasive species are recognized as a leading threat to ecosystems and their management is expensive, time consuming, and labor intensive. Therefore, it is important to review both benefits and detriments of the species to inform appropriate management decisions. Red mangrove was introduced to Moloka'i, Hawaii in 1902 to mitigate the effects of soil erosion and has since spread along the coast and to adjacent islands creating novel habitat. This study assessed both biological services and social attitudes towards Moloka'i's non-native mangroves to provide a comprehensive evaluation of the species. Zooplankton community structure was examined in mangrove and non-mangrove sites and found to be different depending on the amount of mangroves present. Surveys of Moloka'i residents revealed no majority attitude towards mangroves nor support for complete eradication but residents were highly supportive of active management. Approaching other novel ecosystems created by established non-native species from a socio-ecological view may become more crucial as changes in climate, demographics, and environmental conditions further complicate effects. In our globalized world, non-native species introductions will continue to have both positive and negative effects that vary over time. Therefore, assessment of both social and ecological perspectives may lead to more effective management with greater community support. Close

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

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

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