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• 1. [Article] Plant Nitrogen Concentration and Isotopic Composition in Residential Lawns Across Seven US Cities

  Human drivers are often proposed to be stronger than biophysical drivers in influencing ecosystem structure and function in highly urbanized areas. In residential land cover, private yards are influenced ...

  Citation × Citation Citation Abstract Copy Title: Plant Nitrogen Concentration and Isotopic Composition in Residential Lawns Across Seven US Cities Author: Trammell, Tara, Pataki, Diane E., Cavender-Bares, Jeannine, Groffman, Peter M., Hall, Sharon J. Year: 2016 Human drivers are often proposed to be stronger than biophysical drivers in influencing ecosystem structure and function in highly urbanized areas. In residential land cover, private yards are influenced by individual homeowner preferences and actions while also experiencing large-scale human and biophysical drivers. We studied plant nitrogen (%N) and N stable isotopic composition (δ15N) in residential yards and paired native ecosystems in seven cities across the US that span major ecological biomes and climatic regions: Baltimore, Boston, Los Angeles, Miami, Minneapolis-St. Paul, Phoenix, and Salt Lake City. We found that residential lawns in three cities had enriched plant δ15N (P < 0.03) and in six cities higher plant N (%) relative to the associated native ecosystems (P < 0.05). Plant δ15N was progressively depleted across a gradient of urban density classes in Baltimore and Boston (P < 0.05). Lawn fertilization was associated with depleted plant δ15N in Boston and Los Angeles (P < 0.05), and organic fertilizer additions were associated with enriched plant δ15N in Los Angeles and Salt Lake City (P < 0.04). Plant δ15N was significantly enriched as a function of housing age in Baltimore (r2 = 0.27, P < 0.02), Boston (r2 = 0.27, P < 0.01), and Los Angeles (r2 = 0.34, P < 0.01). These patterns in plant δ15N and plant N (%) across these cities suggests that N sources to lawns, as well as greater rates of N cycling combined with subsequent N losses, may be important drivers of plant N dynamics in lawn ecosystems at the national scale. Title: Plant Nitrogen Concentration and Isotopic Composition in Residential Lawns Across Seven US Cities Author: Trammell, Tara, Pataki, Diane E., Cavender-Bares, Jeannine, Groffman, Peter M., Hall, Sharon J. Year: 2016 Human drivers are often proposed to be stronger than biophysical drivers in influencing ecosystem structure and function in highly urbanized areas. In residential land cover, private yards are influenced by individual homeowner preferences and actions while also experiencing large-scale human and biophysical drivers. We studied plant nitrogen (%N) and N stable isotopic composition (δ15N) in residential yards and paired native ecosystems in seven cities across the US that span major ecological biomes and climatic regions: Baltimore, Boston, Los Angeles, Miami, Minneapolis-St. Paul, Phoenix, and Salt Lake City. We found that residential lawns in three cities had enriched plant δ15N (P < 0.03) and in six cities higher plant N (%) relative to the associated native ecosystems (P < 0.05). Plant δ15N was progressively depleted across a gradient of urban density classes in Baltimore and Boston (P < 0.05). Lawn fertilization was associated with depleted plant δ15N in Boston and Los Angeles (P < 0.05), and organic fertilizer additions were associated with enriched plant δ15N in Los Angeles and Salt Lake City (P < 0.04). Plant δ15N was significantly enriched as a function of housing age in Baltimore (r2 = 0.27, P < 0.02), Boston (r2 = 0.27, P < 0.01), and Los Angeles (r2 = 0.34, P < 0.01). These patterns in plant δ15N and plant N (%) across these cities suggests that N sources to lawns, as well as greater rates of N cycling combined with subsequent N losses, may be important drivers of plant N dynamics in lawn ecosystems at the national scale. Close

• 2. [Article] Convergence of Microclimate in Residential Landscapes Across Diverse Cities in the United States

  Context The urban heat island (UHI) is a welldocumented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single ...

  Citation × Citation Citation Abstract Copy Title: Convergence of Microclimate in Residential Landscapes Across Diverse Cities in the United States Author: Hall, Sharon J., Learned, J, Ruddell, Benjamin, Larson, Kelli L., Cavender-Bares, Jeannine, Bettez, Neil D., Groffman, Peter M., Grove, J. Morgan, Heffernan, James B., Hobbie, Sarah E., Larson, Kristen, Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Ogden, Laura A., Pataki, Diane E., Pearse, William D., Polsky, Colin, Chowdhury, Rinku Roy, Steele, Meredith K., Trammell, Tara Year: 2015 Context The urban heat island (UHI) is a welldocumented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single cities surrounded by standardized land cover. Relatively few studies have explored continental-scale climatic patterns within common urban microenvironments such as residential landscapes that may affect human comfort. Objectives We tested the urban homogenization hypothesis which states that structure and function in cities exhibit ecological ‘‘sameness’’ across diverse regions relative to the native ecosystems they replaced. Methods We deployed portable micrometeorological sensors to compare air temperature and humidity in residential yards and native landscapes across six U.S. cities that span a range of climates (Phoenix, AZ; Los Angeles, CA; Minneapolis-St. Paul, MN; Boston, MA; Baltimore, MD; and Miami, FL). Results Microclimate in residential ecosystems was more similar among cities than among native ecosystems, particularly during the calm morning hours. Maximum regional actual evapotranspiration (AET) was related to the morning residential microclimate effect. Residential yards in cities with maximum AET \50–65 cm/year (Phoenix and Los Angeles) were generally cooler and more humid than nearby native shrublands during summer mornings, while yards in cities above this threshold were generally warmer (Baltimore and Miami) and drier (Miami) than native forests. On average, temperature and absolute humidity were *6 % less variable among residential ecosystems than among native ecosystems from diverse regions. Conclusions These data suggest that common residential land cover and structural characteristics lead to microclimatic convergence across diverse regions at the continental scale. Title: Convergence of Microclimate in Residential Landscapes Across Diverse Cities in the United States Author: Hall, Sharon J., Learned, J, Ruddell, Benjamin, Larson, Kelli L., Cavender-Bares, Jeannine, Bettez, Neil D., Groffman, Peter M., Grove, J. Morgan, Heffernan, James B., Hobbie, Sarah E., Larson, Kristen, Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Ogden, Laura A., Pataki, Diane E., Pearse, William D., Polsky, Colin, Chowdhury, Rinku Roy, Steele, Meredith K., Trammell, Tara Year: 2015 Context The urban heat island (UHI) is a welldocumented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single cities surrounded by standardized land cover. Relatively few studies have explored continental-scale climatic patterns within common urban microenvironments such as residential landscapes that may affect human comfort. Objectives We tested the urban homogenization hypothesis which states that structure and function in cities exhibit ecological ‘‘sameness’’ across diverse regions relative to the native ecosystems they replaced. Methods We deployed portable micrometeorological sensors to compare air temperature and humidity in residential yards and native landscapes across six U.S. cities that span a range of climates (Phoenix, AZ; Los Angeles, CA; Minneapolis-St. Paul, MN; Boston, MA; Baltimore, MD; and Miami, FL). Results Microclimate in residential ecosystems was more similar among cities than among native ecosystems, particularly during the calm morning hours. Maximum regional actual evapotranspiration (AET) was related to the morning residential microclimate effect. Residential yards in cities with maximum AET \50–65 cm/year (Phoenix and Los Angeles) were generally cooler and more humid than nearby native shrublands during summer mornings, while yards in cities above this threshold were generally warmer (Baltimore and Miami) and drier (Miami) than native forests. On average, temperature and absolute humidity were *6 % less variable among residential ecosystems than among native ecosystems from diverse regions. Conclusions These data suggest that common residential land cover and structural characteristics lead to microclimatic convergence across diverse regions at the continental scale. Close

• 3. [Article] The Aquarium Trade as an Invasion Pathway in the Pacific Northwest

  The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation ...

  Citation × Citation Citation Abstract Copy Title: The Aquarium Trade as an Invasion Pathway in the Pacific Northwest Author: Strecker, Angela L., Campbell, Philip M., Olden, Julian D. Year: 2011 The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation of the ornamental pet trade as an invasion pathway in the Pacific Northwest region of the United States, where a moderate climate and a large human population present ample opportunities for the introduction and establishment of aquarium trade species. Results from a regional survey of pet stores found that the number of fish (n=400) and plant (n=124) species currently in the aquarium trade is vast. Pet stores import thousands of fish every month, the majority of which (58%) are considered to pose an ecological threat to native ecosystems. Our propagule pressure model suggests that approximately 2,500 fish (maximum 21,000 individuals) are likely released annually to the Puget Sound region by aquarists, and that water temperatures in many parts of Washington are suitable for establishment of populations. In conclusion, the aquarium trade may be a significant source of past and future invasions in the Pacific Northwest, and we recommend enhanced public education programs, greater regulation of the aquarium industry, and improved legislation of nonnative species in the ornamental trade. Title: The Aquarium Trade as an Invasion Pathway in the Pacific Northwest Author: Strecker, Angela L., Campbell, Philip M., Olden, Julian D. Year: 2011 The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation of the ornamental pet trade as an invasion pathway in the Pacific Northwest region of the United States, where a moderate climate and a large human population present ample opportunities for the introduction and establishment of aquarium trade species. Results from a regional survey of pet stores found that the number of fish (n=400) and plant (n=124) species currently in the aquarium trade is vast. Pet stores import thousands of fish every month, the majority of which (58%) are considered to pose an ecological threat to native ecosystems. Our propagule pressure model suggests that approximately 2,500 fish (maximum 21,000 individuals) are likely released annually to the Puget Sound region by aquarists, and that water temperatures in many parts of Washington are suitable for establishment of populations. In conclusion, the aquarium trade may be a significant source of past and future invasions in the Pacific Northwest, and we recommend enhanced public education programs, greater regulation of the aquarium industry, and improved legislation of nonnative species in the ornamental trade. Close

• 4. [Article] Oregon Natural Areas Plan

  The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, ...

  Citation × Citation Citation Abstract Copy Title: Oregon Natural Areas Plan Author: Oregon Natural Heritage Advisory Council Year: 2010 The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, deserts, marshes, estuaries, dunes, rocky headlands, lakes and streams. There are a number of reasons it is so diverse. First are the extremes of climate, with rainfall ranging from over 200 inches a year along Oregon’s north coast, to less than 7 inches a year in the Alvord Desert, and temperatures from the very mild banana belt along the coast near the California border to the extremes of the high alpine areas of the Wallowa Mountains. Secondly, Oregon is diverse geographically and geologically, having ancient serpentine landscapes in the Siskiyou Mountains and recent volcanics in the Cascades and the deepest gorge in North America at Hells Canyon. Lastly, Oregon is a floristic crossroads, with arctic boreal species finding their southern limit, Rocky Mountain species common in northeastern Oregon, Great Basin species in southeastern Oregon, and California coastal and Sierra species in the southwest, all mixing with native northwestern taxa to create a wide array of habitats. Title: Oregon Natural Areas Plan Author: Oregon Natural Heritage Advisory Council Year: 2010 The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, deserts, marshes, estuaries, dunes, rocky headlands, lakes and streams. There are a number of reasons it is so diverse. First are the extremes of climate, with rainfall ranging from over 200 inches a year along Oregon’s north coast, to less than 7 inches a year in the Alvord Desert, and temperatures from the very mild banana belt along the coast near the California border to the extremes of the high alpine areas of the Wallowa Mountains. Secondly, Oregon is diverse geographically and geologically, having ancient serpentine landscapes in the Siskiyou Mountains and recent volcanics in the Cascades and the deepest gorge in North America at Hells Canyon. Lastly, Oregon is a floristic crossroads, with arctic boreal species finding their southern limit, Rocky Mountain species common in northeastern Oregon, Great Basin species in southeastern Oregon, and California coastal and Sierra species in the southwest, all mixing with native northwestern taxa to create a wide array of habitats. Close

• 5. [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

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

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

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

• 7. [Article] Fish Species Introductions Provide Novel Insights into the Patterns and Drivers of Phylogenetic Structure in Freshwaters

  Despite long-standing interest of terrestrial ecologists, freshwater ecosystems are a fertile, yet unappreciated, testing ground for applying community phylogenetics to uncover mechanisms of species assembly. ...

  Citation × Citation Citation Abstract Copy Title: Fish Species Introductions Provide Novel Insights into the Patterns and Drivers of Phylogenetic Structure in Freshwaters Author: Strecker, Angela L., Olden, Julian D. Year: 2014 Despite long-standing interest of terrestrial ecologists, freshwater ecosystems are a fertile, yet unappreciated, testing ground for applying community phylogenetics to uncover mechanisms of species assembly. We quantify phylogenetic clustering and overdispersion of native and non-native fishes of a large river basin in the American Southwest to test for the mechanisms (environmental filtering versus competitive exclusion) and spatial scales influencing community structure. Contrary to expectations, non-native species were phylogenetically clustered and related to natural environmental conditions, whereas native species were not phylogenetically structured, likely reflecting human-related changes to the basin. The species that are most invasive (in terms of ecological impacts) tended to be the most phylogenetically divergent from natives across watersheds, but not within watersheds, supporting the hypothesis that Darwin's naturalization conundrum is driven by the spatial scale. Phylogenetic distinctiveness may facilitate non-native establishment at regional scales, but environmental filtering restricts local membership to closely related species with physiological tolerances for current environments. By contrast, native species may have been phylogenetically clustered in historical times, but species loss from contemporary populations by anthropogenic activities has likely shaped the phylogenetic signal. Our study implies that fundamental mechanisms of community assembly have changed, with fundamental consequences for the biogeography of both native and non-native species. Title: Fish Species Introductions Provide Novel Insights into the Patterns and Drivers of Phylogenetic Structure in Freshwaters Author: Strecker, Angela L., Olden, Julian D. Year: 2014 Despite long-standing interest of terrestrial ecologists, freshwater ecosystems are a fertile, yet unappreciated, testing ground for applying community phylogenetics to uncover mechanisms of species assembly. We quantify phylogenetic clustering and overdispersion of native and non-native fishes of a large river basin in the American Southwest to test for the mechanisms (environmental filtering versus competitive exclusion) and spatial scales influencing community structure. Contrary to expectations, non-native species were phylogenetically clustered and related to natural environmental conditions, whereas native species were not phylogenetically structured, likely reflecting human-related changes to the basin. The species that are most invasive (in terms of ecological impacts) tended to be the most phylogenetically divergent from natives across watersheds, but not within watersheds, supporting the hypothesis that Darwin's naturalization conundrum is driven by the spatial scale. Phylogenetic distinctiveness may facilitate non-native establishment at regional scales, but environmental filtering restricts local membership to closely related species with physiological tolerances for current environments. By contrast, native species may have been phylogenetically clustered in historical times, but species loss from contemporary populations by anthropogenic activities has likely shaped the phylogenetic signal. Our study implies that fundamental mechanisms of community assembly have changed, with fundamental consequences for the biogeography of both native and non-native species. Close

• 8. [Article] Riparian Wetland Plant Response to Livestock Exclusion in the Lower Columbia River Basin

  The purpose of this study was to examine the characteristics of riparian plant communities along a gradient of livestock exclusion in the Lower Columbia River Basin (LCRB) located in the Pacific Northwest ...

  Citation × Citation Citation Abstract Copy Title: Riparian Wetland Plant Response to Livestock Exclusion in the Lower Columbia River Basin Author: Kidd, S. A., Yeakley, J. Alan Year: 2015 The purpose of this study was to examine the characteristics of riparian plant communities along a gradient of livestock exclusion in the Lower Columbia River Basin (LCRB) located in the Pacific Northwest region of the United States. Livestock exclusion from riparian wetlands is a common passive restoration technique. Few studies, however, have focused on the effects of livestock grazing or the exclusion of livestock grazing on these ecosystems. Vegetation community composition was examined in two passive restoration sites, three and 13 years since livestock exclusion, and in a reference site with continued livestock grazing. We hypothesized native plant species richness would be lower in the excluded wetlands than in the grazed wetland due to the competitive exclusion from an increase in non-native plant dominance in the absence of grazing. The grazed wetland had significantly (P < 0.02) greater mean total species richness (23.3 ± 1.6; mean ± 1 standard error), native (10.2 ± 0.5), and non-native (12 ± 1.5) species richness than both the excluded wetlands. Mean total species richness did not differ significantly (P = 0.088) between the three-year (12 ± 1.4) and 13-year (5.5 ± 2.3) excluded wetlands. Mean native and non-native species richness also did not differ significantly (native P = 0.088. non-native P = 0.064) between the three-year (native 6.3 ± 0.6, non-native 5 ± 2.3) and 13-year (native 2.8 ± 1.3, non-native 2.7 ± 1.1) excluded wetlands. However, native species abundance as indicated by percent cover was significantly (P < 0.02) lower in the 13-year excluded wetland (4.2 ± 2.0%) than both the three-year excluded (51.5 ± 3.9%) and grazed (23.2 ± 3.3%) wetlands. The invasive grass, Phalaris arundinacea (reed canarygrass), was found to be the dominant vegetation cover in all three wetlands, with average relative cover ranging from 95.2 ± 2.0% at the 13-year exclusion site to 52.8 ± 4.1% at the grazing site, and 43.0 ± 4.0% cover at the three-year exclusion site. These observations suggest that livestock exclusion alone may be an ineffective strategy for restoring riparian plant communities in regions such as LCRB where invasive species like reed canarygrass are abundant. More effective management alternatives might include short-term livestock exclusion and reintroduced targeted grazing to both reduce livestock impacts and control reed canarygrass dominance. Title: Riparian Wetland Plant Response to Livestock Exclusion in the Lower Columbia River Basin Author: Kidd, S. A., Yeakley, J. Alan Year: 2015 The purpose of this study was to examine the characteristics of riparian plant communities along a gradient of livestock exclusion in the Lower Columbia River Basin (LCRB) located in the Pacific Northwest region of the United States. Livestock exclusion from riparian wetlands is a common passive restoration technique. Few studies, however, have focused on the effects of livestock grazing or the exclusion of livestock grazing on these ecosystems. Vegetation community composition was examined in two passive restoration sites, three and 13 years since livestock exclusion, and in a reference site with continued livestock grazing. We hypothesized native plant species richness would be lower in the excluded wetlands than in the grazed wetland due to the competitive exclusion from an increase in non-native plant dominance in the absence of grazing. The grazed wetland had significantly (P < 0.02) greater mean total species richness (23.3 ± 1.6; mean ± 1 standard error), native (10.2 ± 0.5), and non-native (12 ± 1.5) species richness than both the excluded wetlands. Mean total species richness did not differ significantly (P = 0.088) between the three-year (12 ± 1.4) and 13-year (5.5 ± 2.3) excluded wetlands. Mean native and non-native species richness also did not differ significantly (native P = 0.088. non-native P = 0.064) between the three-year (native 6.3 ± 0.6, non-native 5 ± 2.3) and 13-year (native 2.8 ± 1.3, non-native 2.7 ± 1.1) excluded wetlands. However, native species abundance as indicated by percent cover was significantly (P < 0.02) lower in the 13-year excluded wetland (4.2 ± 2.0%) than both the three-year excluded (51.5 ± 3.9%) and grazed (23.2 ± 3.3%) wetlands. The invasive grass, Phalaris arundinacea (reed canarygrass), was found to be the dominant vegetation cover in all three wetlands, with average relative cover ranging from 95.2 ± 2.0% at the 13-year exclusion site to 52.8 ± 4.1% at the grazing site, and 43.0 ± 4.0% cover at the three-year exclusion site. These observations suggest that livestock exclusion alone may be an ineffective strategy for restoring riparian plant communities in regions such as LCRB where invasive species like reed canarygrass are abundant. More effective management alternatives might include short-term livestock exclusion and reintroduced targeted grazing to both reduce livestock impacts and control reed canarygrass dominance. 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] Biotic Resistance to Invasion: Native Predator Limits Abundance and Distribution of an Introduced Crab

  Introduced species frequently escape the natural enemies (predators, competitors, and parasites) that limit their distribution and abundance in the native range. This reduction in native predators, competitors, ...

  Citation × Citation Citation Abstract Copy Title: Biotic Resistance to Invasion: Native Predator Limits Abundance and Distribution of an Introduced Crab Author: de Rivera, Catherine E., Ruiz, Greg M., Hines, Anson, Jivoff, Paul Year: 2005 Introduced species frequently escape the natural enemies (predators, competitors, and parasites) that limit their distribution and abundance in the native range. This reduction in native predators, competitors, and parasites may result in ecological release in the introduced range. However, biological interactions also can limit the establishment and spread of nonnative populations. The extent to which such biotic resistance occurs is poorly resolved, especially for marine ecosystems. Here we test whether a native predator, the blue crab Callinectes sapidus, affects the abundance and geographic range of the introduced European green crab Carcinus maenas in eastern North America. Both crab species occur in shallow, soft-sediment habitats of bays and estuaries, and their ranges overlap in eastern North America. First, we tested for a negative relationship in the abundances of the two species from trap samples across a 640-km (5.78° latitude) coastal transect. Second, we estimated variation in predation pressure on tethered Carcinus maenas across latitude and as a function of Callinectes sapidus abundance. Third, we measured predation rates on Carcinus maenas by Callinectes sapidus in field and laboratory experiments. Our results support the hypothesis that the native predator Callinectes sapidus provides biotic resistance to invasion and prevents the southward spread and establishment of Carcinus maenas. Within and across bays, Carcinus maenas were significantly less abundant at sites and depths with Callinectes sapidus compared with areas lacking Callinectes sapidus. Moreover, no Carcinus maenas were found in Chesapeake Bay, where Callinectes sapidus were most abundant. Predation of tethered Carcinus maenas increased with Callinectes sapidus abundance. In laboratory and field experiments, Callinectes sapidus preyed readily on Carcinus maenas. Thus, we conclude the predation by Callinectes sapidus, alone or in combination with other factors, limits the abundance and geographic range of an invasive marine species. Title: Biotic Resistance to Invasion: Native Predator Limits Abundance and Distribution of an Introduced Crab Author: de Rivera, Catherine E., Ruiz, Greg M., Hines, Anson, Jivoff, Paul Year: 2005 Introduced species frequently escape the natural enemies (predators, competitors, and parasites) that limit their distribution and abundance in the native range. This reduction in native predators, competitors, and parasites may result in ecological release in the introduced range. However, biological interactions also can limit the establishment and spread of nonnative populations. The extent to which such biotic resistance occurs is poorly resolved, especially for marine ecosystems. Here we test whether a native predator, the blue crab Callinectes sapidus, affects the abundance and geographic range of the introduced European green crab Carcinus maenas in eastern North America. Both crab species occur in shallow, soft-sediment habitats of bays and estuaries, and their ranges overlap in eastern North America. First, we tested for a negative relationship in the abundances of the two species from trap samples across a 640-km (5.78° latitude) coastal transect. Second, we estimated variation in predation pressure on tethered Carcinus maenas across latitude and as a function of Callinectes sapidus abundance. Third, we measured predation rates on Carcinus maenas by Callinectes sapidus in field and laboratory experiments. Our results support the hypothesis that the native predator Callinectes sapidus provides biotic resistance to invasion and prevents the southward spread and establishment of Carcinus maenas. Within and across bays, Carcinus maenas were significantly less abundant at sites and depths with Callinectes sapidus compared with areas lacking Callinectes sapidus. Moreover, no Carcinus maenas were found in Chesapeake Bay, where Callinectes sapidus were most abundant. Predation of tethered Carcinus maenas increased with Callinectes sapidus abundance. In laboratory and field experiments, Callinectes sapidus preyed readily on Carcinus maenas. Thus, we conclude the predation by Callinectes sapidus, alone or in combination with other factors, limits the abundance and geographic range of an invasive marine species. Close

• 11. [Article] Urban and Rural-residential Land Uses: Their Role in Watershed Health and the Rehabilitation of Oregon’s Wild Salmonids

  This technical report by the Independent Multidisciplinary Science Team (IMST) is a comprehensive review of how human activities in urban and rural-residential areas can alter aquatic ecosystems and resulting ...

  Citation × Citation Citation Abstract Copy Title: Urban and Rural-residential Land Uses: Their Role in Watershed Health and the Rehabilitation of Oregon’s Wild Salmonids Author: Harte, Michael, Kaczynski, Victor W., Shock, Clinton C., Yeakley, J. Alan, Hughes, Robert M., Molina, Nancy, Schreck, Carl B. Year: 2010 This technical report by the Independent Multidisciplinary Science Team (IMST) is a comprehensive review of how human activities in urban and rural-residential areas can alter aquatic ecosystems and resulting implications for salmonid recovery, with a geographic focus on the state of Oregon. The following topics are considered in the form of science questions, and comprise the major components of this report: The effects of urban and rural-residential development on Oregon’s watersheds and native wild salmonids. Actions that can be used to avoid or mitigate undesirable changes to aquatic ecosystems near developing urban and rural-residential areas. The benefits and pitfalls of salmonid habitat rehabilitation within established urban or rural-residential areas. Suggested research and monitoring focus areas that will facilitate the recovery of salmonid populations affected by development. The fundamental concepts presented in this report should be applicable to most native salmonid populations across the state. IMST encourages managers and policy-makers with interest in a specific species or geographic region to carefully research local ecological conditions, as well as specific life history characteristics of salmonids in the region. Conserving watershed condition and salmonids in the face of increasing development requires consideration of two distinct sets of processes. First are the human social and economic processes that drive patterns in land use change. Second are the ecological processes, altered by land use, that underlie salmonid habitat changes. This report focuses on the latter and summarizes the effects of rural-residential and urban development on native, wild salmonid populations and the watersheds upon which they depend. Title: Urban and Rural-residential Land Uses: Their Role in Watershed Health and the Rehabilitation of Oregon’s Wild Salmonids Author: Harte, Michael, Kaczynski, Victor W., Shock, Clinton C., Yeakley, J. Alan, Hughes, Robert M., Molina, Nancy, Schreck, Carl B. Year: 2010 This technical report by the Independent Multidisciplinary Science Team (IMST) is a comprehensive review of how human activities in urban and rural-residential areas can alter aquatic ecosystems and resulting implications for salmonid recovery, with a geographic focus on the state of Oregon. The following topics are considered in the form of science questions, and comprise the major components of this report: The effects of urban and rural-residential development on Oregon’s watersheds and native wild salmonids. Actions that can be used to avoid or mitigate undesirable changes to aquatic ecosystems near developing urban and rural-residential areas. The benefits and pitfalls of salmonid habitat rehabilitation within established urban or rural-residential areas. Suggested research and monitoring focus areas that will facilitate the recovery of salmonid populations affected by development. The fundamental concepts presented in this report should be applicable to most native salmonid populations across the state. IMST encourages managers and policy-makers with interest in a specific species or geographic region to carefully research local ecological conditions, as well as specific life history characteristics of salmonids in the region. Conserving watershed condition and salmonids in the face of increasing development requires consideration of two distinct sets of processes. First are the human social and economic processes that drive patterns in land use change. Second are the ecological processes, altered by land use, that underlie salmonid habitat changes. This report focuses on the latter and summarizes the effects of rural-residential and urban development on native, wild salmonid populations and the watersheds upon which they depend. Close

• 12. [Article] Examination of Human Impacts on the Biodiversity and Ecology of Lichen and Moss Communities

  Globally, more than half of the world's population is living in urban areas and it is well accepted that human activities (e.g. climate warming, pollution, landscape homogenization) pose a multitude of ...

  Citation × Citation Citation Abstract Copy Title: Examination of Human Impacts on the Biodiversity and Ecology of Lichen and Moss Communities Author: Prather, Hannah Marie Year: 2017 Globally, more than half of the world's population is living in urban areas and it is well accepted that human activities (e.g. climate warming, pollution, landscape homogenization) pose a multitude of threats to ecosystems. Largely, human-related impacts on biodiversity will hold consequences for larger ecological processes and research looking into human impacts on sensitive epiphytic lichen and moss communities is an emerging area of research. While seemingly small, lichen and moss communities exist on nearly every terrestrial ecosystem on Earth and contribute to whole-system processes (e.g. hydrology, mineral cycling, food web energetics) worldwide. To further examine human impacts on epiphytic communities, I conducted three studies examining urbanization and climate warming effects on epiphytic lichen and moss biodiversity and ecology. In the first study I revisited a historic urban lichen community study to assess how urban lichen communities have responded to regional air quality changes occurring over the last nearly two decades. I further investigated, for the first time, the biodiversity of urban tree canopy-dwelling lichen communities in a native coniferous tree species, Pseudotsuga menziesii. I found that urban parks and forested areas harbor a species rich community of lichens epiphytes. Further, I found evidence for the distinct homogenization of urban epiphytic lichen communities, suggesting that expanding beyond simplistic measures of biodiversity to consider community composition and functional biodiversity may be necessary when assessing the ecology and potential ecosystem services of epiphyte communites within urbanizing landscapes. Next, I present the first tall tree canopy study across a regional gradient of urbanization near Portland, Oregon, USA. I found that tall tree canopy epiphyte communities change dramatically along gradients of increasing urbanization, most notably by the transitioning of species functional groups from sensitive, oligotrophic species to a dominance of urban-tolerant, eutrophic species. The implications these dramatic shifts in species composition have on essential PNW ecosystem processes, like N-fixation and canopy microclimate regulation, is still not well understood and is difficult to formally evaluate. However, I find strong evidence that native conifer trees in urban areas may provide a diversity of essential ecosystem services, including providing stratified habitat for epiphyte communities and their associated micro arthropod communities and the scavenging of atmospherically deposited nutrients. Future work is needed to understand how losses in canopy N fixation and species with large biomass (both lichens and bryophytes) will affect nutrient and hydrologic cycling in the PNW region, which continue to undergo rapid growth and urbanization. The final chapter investigates the impacts of passive warming by Open Top Chambers (OTCs) in moss-dominated ecosystems located on the Western Antarctic Peninsula, an area of increasing climate warming. I compared species-specific temperature effects, moss canopy morphology, sexual reproductive effort and invertebrate communities between OTC and control moss communities for two moss species, Polytrichastrum alpinum and Sanionia uncinata, that make up over 65% of the terrestrial vegetative cover in the area. I found distinct reproductive shifts in P. alpinum under passive warming compared to controls. Moss communities under warming also had substantially larger total invertebrate communities than those in control moss communities, and invertebrate communities were significantly affected by moss species and moss reproductive effort. Further, substantial species-specific thermal differences among contiguous patches of these dominant moss species were revealed. These results suggest that continued warming will differentially impact the reproductive output of Antarctic moss species and is likely to dramatically alter terrestrial ecosystems dynamics from the bottom up. This combined work provides a diverse contribution to the field of epiphyte ecology and biology by providing new insights on how human impacts will affect epiphyte lichen and moss communities across diverse ecosystems, in light of a rapidly changing planet. Title: Examination of Human Impacts on the Biodiversity and Ecology of Lichen and Moss Communities Author: Prather, Hannah Marie Year: 2017 Globally, more than half of the world's population is living in urban areas and it is well accepted that human activities (e.g. climate warming, pollution, landscape homogenization) pose a multitude of threats to ecosystems. Largely, human-related impacts on biodiversity will hold consequences for larger ecological processes and research looking into human impacts on sensitive epiphytic lichen and moss communities is an emerging area of research. While seemingly small, lichen and moss communities exist on nearly every terrestrial ecosystem on Earth and contribute to whole-system processes (e.g. hydrology, mineral cycling, food web energetics) worldwide. To further examine human impacts on epiphytic communities, I conducted three studies examining urbanization and climate warming effects on epiphytic lichen and moss biodiversity and ecology. In the first study I revisited a historic urban lichen community study to assess how urban lichen communities have responded to regional air quality changes occurring over the last nearly two decades. I further investigated, for the first time, the biodiversity of urban tree canopy-dwelling lichen communities in a native coniferous tree species, Pseudotsuga menziesii. I found that urban parks and forested areas harbor a species rich community of lichens epiphytes. Further, I found evidence for the distinct homogenization of urban epiphytic lichen communities, suggesting that expanding beyond simplistic measures of biodiversity to consider community composition and functional biodiversity may be necessary when assessing the ecology and potential ecosystem services of epiphyte communites within urbanizing landscapes. Next, I present the first tall tree canopy study across a regional gradient of urbanization near Portland, Oregon, USA. I found that tall tree canopy epiphyte communities change dramatically along gradients of increasing urbanization, most notably by the transitioning of species functional groups from sensitive, oligotrophic species to a dominance of urban-tolerant, eutrophic species. The implications these dramatic shifts in species composition have on essential PNW ecosystem processes, like N-fixation and canopy microclimate regulation, is still not well understood and is difficult to formally evaluate. However, I find strong evidence that native conifer trees in urban areas may provide a diversity of essential ecosystem services, including providing stratified habitat for epiphyte communities and their associated micro arthropod communities and the scavenging of atmospherically deposited nutrients. Future work is needed to understand how losses in canopy N fixation and species with large biomass (both lichens and bryophytes) will affect nutrient and hydrologic cycling in the PNW region, which continue to undergo rapid growth and urbanization. The final chapter investigates the impacts of passive warming by Open Top Chambers (OTCs) in moss-dominated ecosystems located on the Western Antarctic Peninsula, an area of increasing climate warming. I compared species-specific temperature effects, moss canopy morphology, sexual reproductive effort and invertebrate communities between OTC and control moss communities for two moss species, Polytrichastrum alpinum and Sanionia uncinata, that make up over 65% of the terrestrial vegetative cover in the area. I found distinct reproductive shifts in P. alpinum under passive warming compared to controls. Moss communities under warming also had substantially larger total invertebrate communities than those in control moss communities, and invertebrate communities were significantly affected by moss species and moss reproductive effort. Further, substantial species-specific thermal differences among contiguous patches of these dominant moss species were revealed. These results suggest that continued warming will differentially impact the reproductive output of Antarctic moss species and is likely to dramatically alter terrestrial ecosystems dynamics from the bottom up. This combined work provides a diverse contribution to the field of epiphyte ecology and biology by providing new insights on how human impacts will affect epiphyte lichen and moss communities across diverse ecosystems, in light of a rapidly changing planet. Close

• 13. [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

• 14. [Article] The Limitation of Spread of Non-native Marine Invertebrates from Artificial Structures to Natural Habitats

  Artificial structures created for aquatic anthropogenic activities are often colonized and fouled by many non-native species, few of which have invaded natural areas. Some research has indicated predation ...

  Citation × Citation Citation Abstract Copy Title: The Limitation of Spread of Non-native Marine Invertebrates from Artificial Structures to Natural Habitats Author: McClees, Whitney, de Rivera, Catherine E. Year: 2017 Artificial structures created for aquatic anthropogenic activities are often colonized and fouled by many non-native species, few of which have invaded natural areas. Some research has indicated predation is limiting the spread of non-native species, while other research has indicated that it is dispersal-driven. To determine the effects of dispersal limitation and predation on the risk to surrounding habitats of being invaded by non-native species established on marina docks, we used a three-factor design, deploying seven unglazed ceramic panels per each treatment combination of 1) inside versus outside a marina in Yaquina Bay, Oregon; 2) cage keeping out predators >mesh size, no cage, or partial cage; 3) fixed near the substrata (benthic) versus floating 1m below the surface. We also moved panels of either adults or recruits from floating in the marina to any of the treatment combinations to test if they would have lower survival outside by the substrate. The community on panels suspended in the marina only minimally overlapped with panels outside of the marina near the bottom. However, there was no difference between the cage treatments, which suggests that predators excluded by the cages are not responsible for the observed differences in species richness or composition. Title: The Limitation of Spread of Non-native Marine Invertebrates from Artificial Structures to Natural Habitats Author: McClees, Whitney, de Rivera, Catherine E. Year: 2017 Artificial structures created for aquatic anthropogenic activities are often colonized and fouled by many non-native species, few of which have invaded natural areas. Some research has indicated predation is limiting the spread of non-native species, while other research has indicated that it is dispersal-driven. To determine the effects of dispersal limitation and predation on the risk to surrounding habitats of being invaded by non-native species established on marina docks, we used a three-factor design, deploying seven unglazed ceramic panels per each treatment combination of 1) inside versus outside a marina in Yaquina Bay, Oregon; 2) cage keeping out predators >mesh size, no cage, or partial cage; 3) fixed near the substrata (benthic) versus floating 1m below the surface. We also moved panels of either adults or recruits from floating in the marina to any of the treatment combinations to test if they would have lower survival outside by the substrate. The community on panels suspended in the marina only minimally overlapped with panels outside of the marina near the bottom. However, there was no difference between the cage treatments, which suggests that predators excluded by the cages are not responsible for the observed differences in species richness or composition. Close

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

  Invasive species are recognized as a leading threat to biodiversity 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 biodiversity 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 biodiversity 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

• 16. [Article] Planning Approaches for Water Resources Development in the Lower Mekong Basin

  Governments in the Lower Mekong Basin (LMB) face decisions that involve trade-offs between, for example, the economic benefits from hydropower generation and potentially irreversible negative impacts on ...

  Citation × Citation Citation Abstract Copy Title: Planning Approaches for Water Resources Development in the Lower Mekong Basin Author: Costanza, Robert, Kubiszewski, Ida, Paquet, Peter, King, Jeffrey, Halimi, Shpresa, Sanguanngoi, Hansa, Bach, Nguyen Luong, Frankel, Richard, Ganaseni, Jiragorn, Intralawan, Apisom, Morell, David Year: 2011 Governments in the Lower Mekong Basin (LMB) face decisions that involve trade-offs between, for example, the economic benefits from hydropower generation and potentially irreversible negative impacts on the ecosystems that provide livelihoods and food security to the rural poor. These decisions involve complex problems that are both poorly understood in scientific terms and subject to rapid, potentially catastrophic change over time. A comprehensive, whole systems approach that adequately addresses the risks and uncertainties involved is necessary, but this is a daunting challenge for researchers, decision makers, and managers. They must develop the capacity to plan, coordinate, and implement a program that improves sustainable societal well-being across national boundaries in the face of these uncertainties, which include impacts on native capture fisheries, biodiversity, wetlands and other biological resources, ecosystem services (i.e., the ecological characteristics, functions, or processes that directly or indirectly contribute to human well-being), and indigenous cultures and ways of life. Title: Planning Approaches for Water Resources Development in the Lower Mekong Basin Author: Costanza, Robert, Kubiszewski, Ida, Paquet, Peter, King, Jeffrey, Halimi, Shpresa, Sanguanngoi, Hansa, Bach, Nguyen Luong, Frankel, Richard, Ganaseni, Jiragorn, Intralawan, Apisom, Morell, David Year: 2011 Governments in the Lower Mekong Basin (LMB) face decisions that involve trade-offs between, for example, the economic benefits from hydropower generation and potentially irreversible negative impacts on the ecosystems that provide livelihoods and food security to the rural poor. These decisions involve complex problems that are both poorly understood in scientific terms and subject to rapid, potentially catastrophic change over time. A comprehensive, whole systems approach that adequately addresses the risks and uncertainties involved is necessary, but this is a daunting challenge for researchers, decision makers, and managers. They must develop the capacity to plan, coordinate, and implement a program that improves sustainable societal well-being across national boundaries in the face of these uncertainties, which include impacts on native capture fisheries, biodiversity, wetlands and other biological resources, ecosystem services (i.e., the ecological characteristics, functions, or processes that directly or indirectly contribute to human well-being), and indigenous cultures and ways of life. Close

• 17. [Article] Defining Conservation Priorities for Freshwater Fishes According to Taxonomic, Functional, and Phylogenetic Diversity

  To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent ...

  Citation × Citation Citation Abstract Copy Title: Defining Conservation Priorities for Freshwater Fishes According to Taxonomic, Functional, and Phylogenetic Diversity Author: Strecker, Angela L., Olden, Julian D., Whittier, Joanna B., Paukert, Craig Patrick Year: 2011 To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent attention, research has rarely considered the potential trade-offs between protecting different dimensions of biodiversity and the ecological processes that maintain diversity. We provide the first systematic prioritization for freshwaters (focusing on the highly threatened and globally distinct fish fauna of the Lower Colorado River Basin, USA) simultaneously considering scenarios of: taxonomic, functional, and phylogenetic diversity; contemporary threats to biodiversity (including interactions with nonnative species); and future climate change and human population growth. There was 75% congruence between areas of highest conservation priority for different aspects of biodiversity, suggesting that conservation efforts can concurrently achieve strong complementarity among all types of diversity. However, sizable fractions of the landscape were incongruent across conservation priorities for different diversity scenarios, underscoring the importance of considering multiple dimensions of biodiversity and highlighting catchments that contribute disproportionately to taxonomic, functional, and phylogenetic diversity in the region. Regions of projected human population growth were not concordant with conservation priorities; however, higher human population abundance will likely have indirect effects on native biodiversity by increasing demand for water. This will come in direct conflict with projected reductions in precipitation and warmer temperatures, which have substantial overlap with regions of high contemporary diversity. Native and endemic fishes in arid ecosystems are critically endangered by both current and future threats, but our results highlight the use of systematic conservation planning for the optimal allocation of limited resources that incorporates multiple and complementary conservation values describing taxonomic, functional, and phylogenetic diversity. Title: Defining Conservation Priorities for Freshwater Fishes According to Taxonomic, Functional, and Phylogenetic Diversity Author: Strecker, Angela L., Olden, Julian D., Whittier, Joanna B., Paukert, Craig Patrick Year: 2011 To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent attention, research has rarely considered the potential trade-offs between protecting different dimensions of biodiversity and the ecological processes that maintain diversity. We provide the first systematic prioritization for freshwaters (focusing on the highly threatened and globally distinct fish fauna of the Lower Colorado River Basin, USA) simultaneously considering scenarios of: taxonomic, functional, and phylogenetic diversity; contemporary threats to biodiversity (including interactions with nonnative species); and future climate change and human population growth. There was 75% congruence between areas of highest conservation priority for different aspects of biodiversity, suggesting that conservation efforts can concurrently achieve strong complementarity among all types of diversity. However, sizable fractions of the landscape were incongruent across conservation priorities for different diversity scenarios, underscoring the importance of considering multiple dimensions of biodiversity and highlighting catchments that contribute disproportionately to taxonomic, functional, and phylogenetic diversity in the region. Regions of projected human population growth were not concordant with conservation priorities; however, higher human population abundance will likely have indirect effects on native biodiversity by increasing demand for water. This will come in direct conflict with projected reductions in precipitation and warmer temperatures, which have substantial overlap with regions of high contemporary diversity. Native and endemic fishes in arid ecosystems are critically endangered by both current and future threats, but our results highlight the use of systematic conservation planning for the optimal allocation of limited resources that incorporates multiple and complementary conservation values describing taxonomic, functional, and phylogenetic diversity. Close

• 18. [Article] Neoliberal and Neo-Communal Herring Fisheries in Southeast Alaska: Reframing Sustainability in Marine Ecosystems

  The transformation of Pacific herring (Clupea pallasii) fisheries from communal to commons to neoliberal regulation has had significant impacts on the health and sustainability of marine ecosystems on ...

  Citation × Citation Citation Abstract Copy Title: Neoliberal and Neo-Communal Herring Fisheries in Southeast Alaska: Reframing Sustainability in Marine Ecosystems Author: Thornton, Thomas F., Hebert, Jamie Year: 2015 The transformation of Pacific herring (Clupea pallasii) fisheries from communal to commons to neoliberal regulation has had significant impacts on the health and sustainability of marine ecosystems on the Northwest Coast of North America. Due to their abundance, seasonality, and sensitivity in disturbance, herring were carefully cultivated and protected by coastal Tlingit, Haida, and Tsimshian communities. The early industrial fishing era undermined this communalist approach in favor of an unregulated commons for bait and reduction fisheries, attracting non-local fleets and leading to conflicts with local Natives and tragedy of the commons style overexploitation of herring stocks by the mid-twentieth century. Since the 1970s, a re-regulated neoliberal sac roe fishery for Japanese markets has provided new opportunities for limited commercial permit holders, but with further depredations on local spawning populations. This paper uses frame theory and historical and political ecology to show how this transformation was justified by three critical but dubious (re)framings of Southeast herring populations under modern scientific management: (1) a reductionist framing of single species productivity models, expressed as herring “biomass,” within space and time (baseline scale framing); (2) the selective framing and privileging of human industrial predation under maximum sustainable yield (MSY) within a dynamic ecosystem of multiple predator populations (actor relations framing); and (3) the strategic framing of spawning failure events and policy responses to those events by professional fisheries managers (event–response framing). Finally, the paper argues for a new social–ecological systems approach, based on aboriginal models of herring cultivation, to sustain a commercial, subsistence, and restoration economy for the fishery. Title: Neoliberal and Neo-Communal Herring Fisheries in Southeast Alaska: Reframing Sustainability in Marine Ecosystems Author: Thornton, Thomas F., Hebert, Jamie Year: 2015 The transformation of Pacific herring (Clupea pallasii) fisheries from communal to commons to neoliberal regulation has had significant impacts on the health and sustainability of marine ecosystems on the Northwest Coast of North America. Due to their abundance, seasonality, and sensitivity in disturbance, herring were carefully cultivated and protected by coastal Tlingit, Haida, and Tsimshian communities. The early industrial fishing era undermined this communalist approach in favor of an unregulated commons for bait and reduction fisheries, attracting non-local fleets and leading to conflicts with local Natives and tragedy of the commons style overexploitation of herring stocks by the mid-twentieth century. Since the 1970s, a re-regulated neoliberal sac roe fishery for Japanese markets has provided new opportunities for limited commercial permit holders, but with further depredations on local spawning populations. This paper uses frame theory and historical and political ecology to show how this transformation was justified by three critical but dubious (re)framings of Southeast herring populations under modern scientific management: (1) a reductionist framing of single species productivity models, expressed as herring “biomass,” within space and time (baseline scale framing); (2) the selective framing and privileging of human industrial predation under maximum sustainable yield (MSY) within a dynamic ecosystem of multiple predator populations (actor relations framing); and (3) the strategic framing of spawning failure events and policy responses to those events by professional fisheries managers (event–response framing). Finally, the paper argues for a new social–ecological systems approach, based on aboriginal models of herring cultivation, to sustain a commercial, subsistence, and restoration economy for the fishery. Close

• 19. [Article] OSMB AIS Funds Final Report: Task 1 Boat Ramp Monitoring for New Zealand Mud Snails

  The New Zealand mud snail (Potamopyrgus antipodarum; NZMS) is an invasive species found in a variety of ecosystems in Oregon, including brackish estuaries, heavily used recreational rivers, and highly ...

  Citation × Citation Citation Abstract Copy Title: OSMB AIS Funds Final Report: Task 1 Boat Ramp Monitoring for New Zealand Mud Snails Author: Brenneis, Valance, Cimino, Samuel, Strecker, Angela L. Year: 2013 The New Zealand mud snail (Potamopyrgus antipodarum; NZMS) is an invasive species found in a variety of ecosystems in Oregon, including brackish estuaries, heavily used recreational rivers, and highly trafficked coastal freshwater lakes. NZMS are an invasive species of concern because once established, they may out-compete native invertebrate grazers, such as native insect larvae that provide important food resources for fish, and NZMS themselves provide little nutritional value. Monitoring for the presence and population density of NZMS was performed at boat ramps located along several water bodies in 2006 – 2007. These water bodies were then re-sampled during the summer of 2012 and winter of 2013 to investigate changes in population densities, as well as the potential spread of NZMS. In addition, six brackish estuaries and six freshwater coastal lakes were sampled in the summer of 2013 once again for population densities but also for stable isotope analysis to better understand the influence NZMS may have on these different ecosystem food webs. This work addresses how NZMS densities differ across invaded sites, how densities vary over time, how community diversity in rivers and estuaries varies between sites and over time, whether there is a correlation between NZMS densities and invertebrate diversity, and whether NZMS density correlates with decreasing dietary specificity for competing benthic invertebrates. Samples were sorted, identified, and counted, and stable isotope analyses from the summer 2013 field season were conducted on macroinvertebrates, zooplankton, and primary producers at the UC Davis Stable Isotope Facility. NZMS densities were found to be dynamic, with population densities increasing and decreasing over time and space. Additionally, two waterbodies (the lower Siuslaw River and the Nestucca River Estuary) previously without reported NZMS presence were identified to have established NZMS populations. Across invaded sites during the 2006 and 2012 sampling periods, there was a strong negative correlation between NZMS density and the diversity of the benthic invertebrate community. Within sites, no significant correlation was detected. High NZMS population densities were found to have a significantly negative relationship with detritivore density populations in the freshwater lake sites sampled in the summer of 2013. There were no significant relationships between NZMS and the density of any particular macroinvertebrate feeding habit group in estuaries. Additionally, stable isotope analyses indicated that NZMS at high population densities in the freshwater lakes share a similar stable isotope signature with macroinvertebrate herbivores, but NZMS had a more specific or narrow dietary range suggesting macroinvertebrate herbivores had more generalized diets than NZMS when at high densities. Conversely, NZMS population densities in the brackish estuary ecosystems showed no discernable patterns from the stable isotope analyses to indicate that their presence, either at high or low density, had an effect on the estuarine food webs. We concluded that continued research on long term population dynamics of invasive species like NZMS and their effects on native food webs remain crucial to future management and mitigation. Title: OSMB AIS Funds Final Report: Task 1 Boat Ramp Monitoring for New Zealand Mud Snails Author: Brenneis, Valance, Cimino, Samuel, Strecker, Angela L. Year: 2013 The New Zealand mud snail (Potamopyrgus antipodarum; NZMS) is an invasive species found in a variety of ecosystems in Oregon, including brackish estuaries, heavily used recreational rivers, and highly trafficked coastal freshwater lakes. NZMS are an invasive species of concern because once established, they may out-compete native invertebrate grazers, such as native insect larvae that provide important food resources for fish, and NZMS themselves provide little nutritional value. Monitoring for the presence and population density of NZMS was performed at boat ramps located along several water bodies in 2006 – 2007. These water bodies were then re-sampled during the summer of 2012 and winter of 2013 to investigate changes in population densities, as well as the potential spread of NZMS. In addition, six brackish estuaries and six freshwater coastal lakes were sampled in the summer of 2013 once again for population densities but also for stable isotope analysis to better understand the influence NZMS may have on these different ecosystem food webs. This work addresses how NZMS densities differ across invaded sites, how densities vary over time, how community diversity in rivers and estuaries varies between sites and over time, whether there is a correlation between NZMS densities and invertebrate diversity, and whether NZMS density correlates with decreasing dietary specificity for competing benthic invertebrates. Samples were sorted, identified, and counted, and stable isotope analyses from the summer 2013 field season were conducted on macroinvertebrates, zooplankton, and primary producers at the UC Davis Stable Isotope Facility. NZMS densities were found to be dynamic, with population densities increasing and decreasing over time and space. Additionally, two waterbodies (the lower Siuslaw River and the Nestucca River Estuary) previously without reported NZMS presence were identified to have established NZMS populations. Across invaded sites during the 2006 and 2012 sampling periods, there was a strong negative correlation between NZMS density and the diversity of the benthic invertebrate community. Within sites, no significant correlation was detected. High NZMS population densities were found to have a significantly negative relationship with detritivore density populations in the freshwater lake sites sampled in the summer of 2013. There were no significant relationships between NZMS and the density of any particular macroinvertebrate feeding habit group in estuaries. Additionally, stable isotope analyses indicated that NZMS at high population densities in the freshwater lakes share a similar stable isotope signature with macroinvertebrate herbivores, but NZMS had a more specific or narrow dietary range suggesting macroinvertebrate herbivores had more generalized diets than NZMS when at high densities. Conversely, NZMS population densities in the brackish estuary ecosystems showed no discernable patterns from the stable isotope analyses to indicate that their presence, either at high or low density, had an effect on the estuarine food webs. We concluded that continued research on long term population dynamics of invasive species like NZMS and their effects on native food webs remain crucial to future management and mitigation. Close

• 20. [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

• 21. [Article] Community level impacts associated with the invasion of English ivy (Hedera spp.) in Forest Park: a look at the impacts of ivy on community composition and soil moisture.

  Invasive species degrade ecosystems by altering natural processes and decreasing the abundance and diversity of native flora. Communities with major fluctuations in resource supply allow invasive species ...

  Citation × Citation Citation Abstract Copy Title: Community level impacts associated with the invasion of English ivy (Hedera spp.) in Forest Park: a look at the impacts of ivy on community composition and soil moisture. Author: Copp, Sara Rose Year: 2014 Invasive species degrade ecosystems by altering natural processes and decreasing the abundance and diversity of native flora. Communities with major fluctuations in resource supply allow invasive species to exploit limiting resources making the community prone to invasion. In the Pacific Northwest, urban forests characterized with limited light and seasonally limited soil moisture are being dominated by nonnative English ivy (Hedera spp). Three observational studies were conducted in the Southern end of Forest Park within the Balch Creek Subwatershed in Portland, Oregon in order to understand 1) how English ivy changes over three growing seasons, 2) how the native understory composition responds to English ivy, 3) if the dominance of English ivy reduces soil moisture to neighboring plants, 4) how English ivy and two co-occurring native herbs (Hydrophyllum tenuipes and Vancouveria hexandra) physiologically respond to seasonal changes in soil moisture. Percent cover of the understory community was collected in both 2010 and 2013 growing seasons in 54 plots in order to understand the change in cover over time. Community response and the relationship with soil moisture was analyzed using percent cover of the understory community and associated environmental variables including soil moisture collected in 128 plots during the 2013 field season. Finally, 15 plots with co-occurring Hedera spp, H. tenuipes and V. hexandra were sampled for stomatal conductance, leaf water potential, and associated environmental variables. Results show ivy cover increases on average 14% between 2010 and 2013 while native understory cover increased on average < 1%. Once ivy forms dense cover over 44% there is a reduction of native richness, diversity and herb cover while also an increase in available soil moisture and deciduous canopy cover. There were disparate impacts to different functional groups and between species. As functional group, the herbaceous community was the most impacted by ivy invasion. The shrubs and fern community had a variable response to ivy invasion. Many of the fern and shrub species least impacted by ivy also had associations with high soil moisture and deciduous canopy cover. Finally, data suggests that ivy does not take advantage of seasonally limiting soil moisture to invade the understory community. This study indicates that English ivy is both efficient at water use and may have the ability to obtain water from distant locations throughout the forest. Once established, ivy has the ability to alter the community composition. Ivy removal and habitat restoration are essential in order to maintain and enhance biodiversity in Forest Park. Title: Community level impacts associated with the invasion of English ivy (Hedera spp.) in Forest Park: a look at the impacts of ivy on community composition and soil moisture. Author: Copp, Sara Rose Year: 2014 Invasive species degrade ecosystems by altering natural processes and decreasing the abundance and diversity of native flora. Communities with major fluctuations in resource supply allow invasive species to exploit limiting resources making the community prone to invasion. In the Pacific Northwest, urban forests characterized with limited light and seasonally limited soil moisture are being dominated by nonnative English ivy (Hedera spp). Three observational studies were conducted in the Southern end of Forest Park within the Balch Creek Subwatershed in Portland, Oregon in order to understand 1) how English ivy changes over three growing seasons, 2) how the native understory composition responds to English ivy, 3) if the dominance of English ivy reduces soil moisture to neighboring plants, 4) how English ivy and two co-occurring native herbs (Hydrophyllum tenuipes and Vancouveria hexandra) physiologically respond to seasonal changes in soil moisture. Percent cover of the understory community was collected in both 2010 and 2013 growing seasons in 54 plots in order to understand the change in cover over time. Community response and the relationship with soil moisture was analyzed using percent cover of the understory community and associated environmental variables including soil moisture collected in 128 plots during the 2013 field season. Finally, 15 plots with co-occurring Hedera spp, H. tenuipes and V. hexandra were sampled for stomatal conductance, leaf water potential, and associated environmental variables. Results show ivy cover increases on average 14% between 2010 and 2013 while native understory cover increased on average < 1%. Once ivy forms dense cover over 44% there is a reduction of native richness, diversity and herb cover while also an increase in available soil moisture and deciduous canopy cover. There were disparate impacts to different functional groups and between species. As functional group, the herbaceous community was the most impacted by ivy invasion. The shrubs and fern community had a variable response to ivy invasion. Many of the fern and shrub species least impacted by ivy also had associations with high soil moisture and deciduous canopy cover. Finally, data suggests that ivy does not take advantage of seasonally limiting soil moisture to invade the understory community. This study indicates that English ivy is both efficient at water use and may have the ability to obtain water from distant locations throughout the forest. Once established, ivy has the ability to alter the community composition. Ivy removal and habitat restoration are essential in order to maintain and enhance biodiversity in Forest Park. Close

• 22. [Article] Northern Range Expansion and Coastal Occurrences of the New Zealand Mud Snail Potamopyrgus Antipodarum (Gray, 1843) in the Northeast Pacific

  The New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) is a common invasive species in fresh and brackish water ecosystems in Europe, Australia, Japan, and North America. In some invaded habitats, ...

  Citation × Citation Citation Abstract Copy Title: Northern Range Expansion and Coastal Occurrences of the New Zealand Mud Snail Potamopyrgus Antipodarum (Gray, 1843) in the Northeast Pacific Author: Davidson, Timothy Mathias, Brenneis, Valance E. F., de Rivera, Catherine E., Draheim, Robyn, Gillespie, Graham E. Year: 2008 The New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) is a common invasive species in fresh and brackish water ecosystems in Europe, Australia, Japan, and North America. In some invaded habitats, P. antipodarum can reach high densities (over 500,000 snails m-2) and dominate the biomass of the benthos, leading to detrimental impacts to native biota and changes in ecosystem dynamics. We report the previously unpublished occurrence of P. antipodarum in thirteen fresh and brackish water systems adjacent to the Pacific coast of North America including a new northern range for P. antipodarum: Port Alberni, Vancouver Island, British Columbia, Canada (49.2479º, -124.8395º). We hypothesize the snail was spread from the Columbia River Estuary to Port Alberni via recreational watercraft or infected fishing equipment. Its discovery in Port Alberni reveals the potential for other aquatic nuisance species in the lower Columbia River to spread to British Columbia. Resource managers on the Pacific coast should remain vigilant and educate the public to prevent the further spread of the P. antipodarum as well as other aquatic invaders. Title: Northern Range Expansion and Coastal Occurrences of the New Zealand Mud Snail Potamopyrgus Antipodarum (Gray, 1843) in the Northeast Pacific Author: Davidson, Timothy Mathias, Brenneis, Valance E. F., de Rivera, Catherine E., Draheim, Robyn, Gillespie, Graham E. Year: 2008 The New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) is a common invasive species in fresh and brackish water ecosystems in Europe, Australia, Japan, and North America. In some invaded habitats, P. antipodarum can reach high densities (over 500,000 snails m-2) and dominate the biomass of the benthos, leading to detrimental impacts to native biota and changes in ecosystem dynamics. We report the previously unpublished occurrence of P. antipodarum in thirteen fresh and brackish water systems adjacent to the Pacific coast of North America including a new northern range for P. antipodarum: Port Alberni, Vancouver Island, British Columbia, Canada (49.2479º, -124.8395º). We hypothesize the snail was spread from the Columbia River Estuary to Port Alberni via recreational watercraft or infected fishing equipment. Its discovery in Port Alberni reveals the potential for other aquatic nuisance species in the lower Columbia River to spread to British Columbia. Resource managers on the Pacific coast should remain vigilant and educate the public to prevent the further spread of the P. antipodarum as well as other aquatic invaders. Close

• 23. [Article] Invasive Predator, Bythotrephes, has Varied Effects on Ecosystem Function in Freshwater Lakes

  Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes ...

  Citation × Citation Citation Abstract Copy Title: Invasive Predator, Bythotrephes, has Varied Effects on Ecosystem Function in Freshwater Lakes Author: Strecker, Angela L., Arnott, Shelley E. Year: 2008 Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes on two measures of ecosystem function during a four month observational study of freshwater lakes on the boreal shield. Bythotrephes-invaded lakes had significantly lower epilimnetic zooplankton abundance and production compared to reference lakes. On average, Bythotrephes consumed 34% ofzooplankton production when it was present in lakes. There was some evidence of changes in the timing of zooplankton production, as well as shifts to cooler, less productive habitats, which may lessen the overall effect of the invader on the transfer of energy to higher trophic levels. We experimentally demonstrated a weak trophic cascade where invader predation reduced zooplankton biomass, and subsequently increased phytoplankton growth. However, the response was small in magnitude and not biologically relevant at the whole lake- scale. The most conspicuous effect of Bythotrephes that we measured was a diversion of energy away from native predators at higher trophic levels. Title: Invasive Predator, Bythotrephes, has Varied Effects on Ecosystem Function in Freshwater Lakes Author: Strecker, Angela L., Arnott, Shelley E. Year: 2008 Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes on two measures of ecosystem function during a four month observational study of freshwater lakes on the boreal shield. Bythotrephes-invaded lakes had significantly lower epilimnetic zooplankton abundance and production compared to reference lakes. On average, Bythotrephes consumed 34% ofzooplankton production when it was present in lakes. There was some evidence of changes in the timing of zooplankton production, as well as shifts to cooler, less productive habitats, which may lessen the overall effect of the invader on the transfer of energy to higher trophic levels. We experimentally demonstrated a weak trophic cascade where invader predation reduced zooplankton biomass, and subsequently increased phytoplankton growth. However, the response was small in magnitude and not biologically relevant at the whole lake- scale. The most conspicuous effect of Bythotrephes that we measured was a diversion of energy away from native predators at higher trophic levels. Close

• 24. [Article] The Wildlands Project Outside North America

  The Wildlands Project seeks to create a connected system of protected areas across North America that will ensure the survival of all native species, including top predators and wideranging species, in ...

  Citation × Citation Citation Abstract Copy Title: The Wildlands Project Outside North America Author: Johns, David Year: 2003 The Wildlands Project seeks to create a connected system of protected areas across North America that will ensure the survival of all native species, including top predators and wideranging species, in the context of fully functioning ecosystems. Core protected areas are designated based on the biological needs of key species and the requirements of critical ecological processes. To work they must have, or will be restored to have, those attributes traditionally ascribed to wilderness. Some critics argue that The Wildlands Project model is inapplicable to other parts of the world, especially the developing world. The inapplicability is based on nonbiological considerations. The applicability of Wildlands type conservation outside of North America is examined in light of largescale conservation work in Latin America and Asia. In both regions, conservation efforts similar to those of The Wildlands Project are underway and show promise. There are important differences, but the similarities are significant enough to suggest the approach can be applied. The similarities between conservation work in North America, Latin America, and Asia is attributable in some cases to Wildlands Project influence. In other cases, similarities are due to similar strategies emerging from similar conditions leading to species loss. Title: The Wildlands Project Outside North America Author: Johns, David Year: 2003 The Wildlands Project seeks to create a connected system of protected areas across North America that will ensure the survival of all native species, including top predators and wideranging species, in the context of fully functioning ecosystems. Core protected areas are designated based on the biological needs of key species and the requirements of critical ecological processes. To work they must have, or will be restored to have, those attributes traditionally ascribed to wilderness. Some critics argue that The Wildlands Project model is inapplicable to other parts of the world, especially the developing world. The inapplicability is based on nonbiological considerations. The applicability of Wildlands type conservation outside of North America is examined in light of largescale conservation work in Latin America and Asia. In both regions, conservation efforts similar to those of The Wildlands Project are underway and show promise. There are important differences, but the similarities are significant enough to suggest the approach can be applied. The similarities between conservation work in North America, Latin America, and Asia is attributable in some cases to Wildlands Project influence. In other cases, similarities are due to similar strategies emerging from similar conditions leading to species loss. Close

• 25. [Article] Riparian Wetland Response to Livestock Exclusion in the Lower Columbia River Basin

  The purpose of this study was to examine the characteristics of riparian plant communities along a succession gradient of livestock exclusion in the Lower Columbia River Basin (LCRB). Livestock exclusion ...

  Citation × Citation Citation Abstract Copy Title: Riparian Wetland Response to Livestock Exclusion in the Lower Columbia River Basin Author: Holmen, Sarah Ann Year: 2011 The purpose of this study was to examine the characteristics of riparian plant communities along a succession gradient of livestock exclusion in the Lower Columbia River Basin (LCRB). Livestock exclusion is an example of a passive restoration practice throughout the region. However, few studies have focused on the effects of livestock or livestock exclusion on riparian wetland ecosystems in this area. Two passive restoration sites, 3 and 13 years since livestock exclusion, and a control site with a continued livestock grazing presence were examined. It was hypothesized that native plant species richness would be lower in the excluded wetlands than in the grazed wetland due to the competitive exclusion from an increase in non-native plant dominance in the absence of grazing. Data were collected along six (45-60m) randomly distributed transects which were aligned perpendicular to the wetland shoreline of each site, providing a total of 18 transects with an accumulative length of approximately 990 meters. Vegetation cover data were collected for 10 cm intervals along these transects using the line intercept method during low water periods in August and September of 2009. The Kruskal-Wallis one-way nonparametric analysis of variance by ranks and the Mann-Whitney U test were used to detect significant (p Title: Riparian Wetland Response to Livestock Exclusion in the Lower Columbia River Basin Author: Holmen, Sarah Ann Year: 2011 The purpose of this study was to examine the characteristics of riparian plant communities along a succession gradient of livestock exclusion in the Lower Columbia River Basin (LCRB). Livestock exclusion is an example of a passive restoration practice throughout the region. However, few studies have focused on the effects of livestock or livestock exclusion on riparian wetland ecosystems in this area. Two passive restoration sites, 3 and 13 years since livestock exclusion, and a control site with a continued livestock grazing presence were examined. It was hypothesized that native plant species richness would be lower in the excluded wetlands than in the grazed wetland due to the competitive exclusion from an increase in non-native plant dominance in the absence of grazing. Data were collected along six (45-60m) randomly distributed transects which were aligned perpendicular to the wetland shoreline of each site, providing a total of 18 transects with an accumulative length of approximately 990 meters. Vegetation cover data were collected for 10 cm intervals along these transects using the line intercept method during low water periods in August and September of 2009. The Kruskal-Wallis one-way nonparametric analysis of variance by ranks and the Mann-Whitney U test were used to detect significant (p Close

• 26. [Article] Green Roofs and Urban Biodiversity: Their Role as Invertebrate Habitat and the Effect of Design on Beetle Community

  With over half the world's population now living in cities, urban areas represent one of earth's few ecosystems that are increasing in extent, and are sites of altered biogeochemical cycles, habitat fragmentation, ...

  Citation × Citation Citation Abstract Copy Title: Green Roofs and Urban Biodiversity: Their Role as Invertebrate Habitat and the Effect of Design on Beetle Community Author: Gonsalves, Sydney Marie Year: 2016 With over half the world's population now living in cities, urban areas represent one of earth's few ecosystems that are increasing in extent, and are sites of altered biogeochemical cycles, habitat fragmentation, and changes in biodiversity. However, urban green spaces, including green roofs, can also provide important pools of biodiversity and contribute to regional gamma diversity, while novel species assemblages can enhance some ecosystem services. Green roofs may also mitigate species loss in urban areas and have been shown to support a surprising diversity of invertebrates, including rare and endangered species. In the first part of this study I reviewed the literature on urban invertebrate communities and diversity to better understand the role of green roofs in providing habitat in the context of the larger urban mosaic. My review concluded that, while other factors such as surrounding land use and connectivity are also important to specific invertebrate taxa, local habitat variables contribute substantially to the structure and diversity of urban invertebrate communities. The importance of local habitat variables in urban green spaces and strong support for the habitat complexity hypothesis in a number of other ecosystems has led to proposals that "biodiverse" roofs--those intentionally designed with varied substrate depth, greater plant diversity, or added elements such as logs or stones--would support greater invertebrate diversity, but there is currently limited peer reviewed data to support this. In order to address the habitat complexity hypothesis in the context of green roofs, in the second part of this study I surveyed three roofs designed primarily for stormwater management, three biodiverse roofs, and five ground-level green spaces, from March until September of 2014 in the Portland metropolitan area. Beetles (Coleoptera) were sampled bi-weekly as representatives of total species diversity. Biodiverse roofs had greater richness, abundance, and diversity of beetle species compared to stormwater roofs, but were not more diverse than ground sites. Both biodiverse roofs and ground sites had approximately 20% native beetle species while stormwater roofs had only 5%. Functional diversity was also higher on biodiverse roofs with an average of seven trophic groups represented, while stormwater roofs averaged only three. Ground sites, biodiverse roofs, and stormwater roofs each grouped distinctively in terms of beetle community composition and biodiverse roof communities were found to be positively correlated with roof age, percent plant cover, average plant height, and plant species richness. These results support the findings of previous studies on the importance of local variables in structuring urban invertebrate communities and suggest that biodiverse design can reliably increase greenroof diversity, with the caution that they remain no replacement for ground level conservation. Title: Green Roofs and Urban Biodiversity: Their Role as Invertebrate Habitat and the Effect of Design on Beetle Community Author: Gonsalves, Sydney Marie Year: 2016 With over half the world's population now living in cities, urban areas represent one of earth's few ecosystems that are increasing in extent, and are sites of altered biogeochemical cycles, habitat fragmentation, and changes in biodiversity. However, urban green spaces, including green roofs, can also provide important pools of biodiversity and contribute to regional gamma diversity, while novel species assemblages can enhance some ecosystem services. Green roofs may also mitigate species loss in urban areas and have been shown to support a surprising diversity of invertebrates, including rare and endangered species. In the first part of this study I reviewed the literature on urban invertebrate communities and diversity to better understand the role of green roofs in providing habitat in the context of the larger urban mosaic. My review concluded that, while other factors such as surrounding land use and connectivity are also important to specific invertebrate taxa, local habitat variables contribute substantially to the structure and diversity of urban invertebrate communities. The importance of local habitat variables in urban green spaces and strong support for the habitat complexity hypothesis in a number of other ecosystems has led to proposals that "biodiverse" roofs--those intentionally designed with varied substrate depth, greater plant diversity, or added elements such as logs or stones--would support greater invertebrate diversity, but there is currently limited peer reviewed data to support this. In order to address the habitat complexity hypothesis in the context of green roofs, in the second part of this study I surveyed three roofs designed primarily for stormwater management, three biodiverse roofs, and five ground-level green spaces, from March until September of 2014 in the Portland metropolitan area. Beetles (Coleoptera) were sampled bi-weekly as representatives of total species diversity. Biodiverse roofs had greater richness, abundance, and diversity of beetle species compared to stormwater roofs, but were not more diverse than ground sites. Both biodiverse roofs and ground sites had approximately 20% native beetle species while stormwater roofs had only 5%. Functional diversity was also higher on biodiverse roofs with an average of seven trophic groups represented, while stormwater roofs averaged only three. Ground sites, biodiverse roofs, and stormwater roofs each grouped distinctively in terms of beetle community composition and biodiverse roof communities were found to be positively correlated with roof age, percent plant cover, average plant height, and plant species richness. These results support the findings of previous studies on the importance of local variables in structuring urban invertebrate communities and suggest that biodiverse design can reliably increase greenroof diversity, with the caution that they remain no replacement for ground level conservation. Close

• 27. [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

• 28. [Article] Salmon at River's End: The Role of the Estuary in the Decline and Recovery of Columbia River salmon

  The continued decline of Columbia River salmon (Oncorhynchus spp.) populations has long focused concerns on habitat changes upriver, particularly the effects of large hydroelectric dams. Increasing evidence ...

  Citation × Citation Citation Abstract Copy Title: Salmon at River's End: The Role of the Estuary in the Decline and Recovery of Columbia River salmon Author: Bottom, Daniel L., Simenstad, Charles A., Burke, Jennifer, Baptista, Antonio M., Jay, David A., Jone, Kim K., Casillas, Edmundo, Schiewe, Michael H. Year: 2005 The continued decline of Columbia River salmon (Oncorhynchus spp.) populations has long focused concerns on habitat changes upriver, particularly the effects of large hydroelectric dams. Increasing evidence that ocean conditions strongly influence salmon production, however, has raised questions about the importance of the estuarine environment to salmon and whether the hydropower system has affected estuarine-rearing habitats. In response to Northwest Power Planning Council recommendations, we initiated a review of what is known about the effects of the hydroelectric system on the hydrology, habitats, and ecology of the Columbia River estuary. Our goal was to develop recommendations for improving estuarine conditions or to identify research that may be needed before appropriate salmon-management changes can be defined. Our review and analyses addressed four major questions: (1) What habitats and processes support native salmon populations during the estuarine phase of their life cycle? (2) Have changes to the estuary had a significant role in salmon decline? (3) What have been the impacts of flow regulation on the hydrology, habitat, and biological interactions in the estuarine ecosystem? (4) What estuarine conditions are necessary to maintain salmonid diversity in the Columbia River basin? Title: Salmon at River's End: The Role of the Estuary in the Decline and Recovery of Columbia River salmon Author: Bottom, Daniel L., Simenstad, Charles A., Burke, Jennifer, Baptista, Antonio M., Jay, David A., Jone, Kim K., Casillas, Edmundo, Schiewe, Michael H. Year: 2005 The continued decline of Columbia River salmon (Oncorhynchus spp.) populations has long focused concerns on habitat changes upriver, particularly the effects of large hydroelectric dams. Increasing evidence that ocean conditions strongly influence salmon production, however, has raised questions about the importance of the estuarine environment to salmon and whether the hydropower system has affected estuarine-rearing habitats. In response to Northwest Power Planning Council recommendations, we initiated a review of what is known about the effects of the hydroelectric system on the hydrology, habitats, and ecology of the Columbia River estuary. Our goal was to develop recommendations for improving estuarine conditions or to identify research that may be needed before appropriate salmon-management changes can be defined. Our review and analyses addressed four major questions: (1) What habitats and processes support native salmon populations during the estuarine phase of their life cycle? (2) Have changes to the estuary had a significant role in salmon decline? (3) What have been the impacts of flow regulation on the hydrology, habitat, and biological interactions in the estuarine ecosystem? (4) What estuarine conditions are necessary to maintain salmonid diversity in the Columbia River basin? Close

• 29. [Article] Response of Sagebrush Steppe Species to Elevated CO2 and Soil Temperature

  Elevated atmospheric CO2 may cause long-term changes in the productivity and species composition of the sagebrush steppe. Few studies, however, have evaluated the effects of increased CO2 on growth and ...

  Citation × Citation Citation Abstract Copy Title: Response of Sagebrush Steppe Species to Elevated CO2 and Soil Temperature Author: Lucash, Melissa S., Farnsworth, Blake, Winner, William E. Year: 2005 Elevated atmospheric CO2 may cause long-term changes in the productivity and species composition of the sagebrush steppe. Few studies, however, have evaluated the effects of increased CO2 on growth and physiology of species important to this ecosystem. Since the response of plants to elevated CO2 may be limited by environmental factors, soil temperature was also examined to determine if low soil temperatures limit CO2 response. To determine how CO2 and soil temperature affect the growth of species native to the sagebrush steppe, bottlebrush squirreltail [Elymus elymoides (Raf.) Swezey], Thurber needlegrass (Stipa thurberiana Piper), and Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle) were grown in ambient (374 mL L–1) or high (567 mL L–1) CO2 and low (13°C) or high (18°C) soil temperature for approximately 4 months. Although soil temperature affected the growth of squirreltail and needlegrass, temperature did not modify their response to elevated CO2. Total biomass of sagebrush was consistent across soil temperature and CO2 treatments, reflecting its slow-growing strategy. All 3 species had higher leaf water-use efficiency at elevated CO2 due to higher net photosynthesis and lower transpiration rates. We conclude that elevated CO2 and soil warming may increase the growth of grasses more than shrubs. Field studies in the sagebrush steppe are necessary to determine if differences in biomass, resulting from changes in CO2 and soil temperature, are exhibited in the field. Title: Response of Sagebrush Steppe Species to Elevated CO2 and Soil Temperature Author: Lucash, Melissa S., Farnsworth, Blake, Winner, William E. Year: 2005 Elevated atmospheric CO2 may cause long-term changes in the productivity and species composition of the sagebrush steppe. Few studies, however, have evaluated the effects of increased CO2 on growth and physiology of species important to this ecosystem. Since the response of plants to elevated CO2 may be limited by environmental factors, soil temperature was also examined to determine if low soil temperatures limit CO2 response. To determine how CO2 and soil temperature affect the growth of species native to the sagebrush steppe, bottlebrush squirreltail [Elymus elymoides (Raf.) Swezey], Thurber needlegrass (Stipa thurberiana Piper), and Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle) were grown in ambient (374 mL L–1) or high (567 mL L–1) CO2 and low (13°C) or high (18°C) soil temperature for approximately 4 months. Although soil temperature affected the growth of squirreltail and needlegrass, temperature did not modify their response to elevated CO2. Total biomass of sagebrush was consistent across soil temperature and CO2 treatments, reflecting its slow-growing strategy. All 3 species had higher leaf water-use efficiency at elevated CO2 due to higher net photosynthesis and lower transpiration rates. We conclude that elevated CO2 and soil warming may increase the growth of grasses more than shrubs. Field studies in the sagebrush steppe are necessary to determine if differences in biomass, resulting from changes in CO2 and soil temperature, are exhibited in the field. Close

• 30. [Article] Direct and Indirect Effects of an Invasive Planktonic Predator on Pelagic Food Webs

  The relative importance of top-down invader effects relative to environmental drivers was determined by sampling crustacean zooplankton, rotifer, and phytoplankton communities in a set of invaded and noninvaded ...

  Citation × Citation Citation Abstract Copy Title: Direct and Indirect Effects of an Invasive Planktonic Predator on Pelagic Food Webs Author: Strecker, Angela L., Beisner, Beatrix E., Arnott, Shelley E., Paterson, Andrew M., Winter, Jennifer G., Johannsson, Ora E., Yan, Norman D. Year: 2011 The relative importance of top-down invader effects relative to environmental drivers was determined by sampling crustacean zooplankton, rotifer, and phytoplankton communities in a set of invaded and noninvaded reference lakes. The non-native invertebrate predator Bythotrephes had significant effects on zooplankton community size structure, rotifers, and phytoplankton taxonomic composition, but no significant effects on crustacean zooplankton taxonomic and functional group composition. Part of the variation in phytoplankton communities was explained by the presence of the invader. Because Bythotrephes is generally known to be a carnivore and to not consume phytoplankton, this effect is likely mediated by the zooplankton community’s response to environmental gradients. Although Bythotrephes appears to indirectly alter phytoplankton composition in invaded lakes, there was no evidence of a trophic cascade, and edible phytoplankton biovolume did not increase in invaded lakes. These complex direct and indirect interactions suggest that effects of invaders may be highly context-dependent, and therefore pose a significant challenge for predicting wider community and ecosystem responses. Title: Direct and Indirect Effects of an Invasive Planktonic Predator on Pelagic Food Webs Author: Strecker, Angela L., Beisner, Beatrix E., Arnott, Shelley E., Paterson, Andrew M., Winter, Jennifer G., Johannsson, Ora E., Yan, Norman D. Year: 2011 The relative importance of top-down invader effects relative to environmental drivers was determined by sampling crustacean zooplankton, rotifer, and phytoplankton communities in a set of invaded and noninvaded reference lakes. The non-native invertebrate predator Bythotrephes had significant effects on zooplankton community size structure, rotifers, and phytoplankton taxonomic composition, but no significant effects on crustacean zooplankton taxonomic and functional group composition. Part of the variation in phytoplankton communities was explained by the presence of the invader. Because Bythotrephes is generally known to be a carnivore and to not consume phytoplankton, this effect is likely mediated by the zooplankton community’s response to environmental gradients. Although Bythotrephes appears to indirectly alter phytoplankton composition in invaded lakes, there was no evidence of a trophic cascade, and edible phytoplankton biovolume did not increase in invaded lakes. These complex direct and indirect interactions suggest that effects of invaders may be highly context-dependent, and therefore pose a significant challenge for predicting wider community and ecosystem responses. Close

• 31. [Article] The Response of Zooplankton Communities in Montane Lakes of Different Fish Stocking Histories to Atmospheric Nitrogen Deposition Simulations

  Freshwater ecosystems are subject to a wide variety of stressors, which can have complex interactions and result in ecological surprises. Non-native fish introductions have drastically reduced the number ...

  Citation × Citation Citation Abstract Copy Title: The Response of Zooplankton Communities in Montane Lakes of Different Fish Stocking Histories to Atmospheric Nitrogen Deposition Simulations Author: Brittain, Jeffrey Thomas Year: 2015 Freshwater ecosystems are subject to a wide variety of stressors, which can have complex interactions and result in ecological surprises. Non-native fish introductions have drastically reduced the number of naturally fishless lakes and have resulted in cascading food web repercussions in aquatic and terrestrial habitats. Additional anthropogenic influences that result from increases in global airborne emissions also threaten wildlife habitat. Atmospheric nitrogen deposition has been recognized as an anthropogenic contributor to acidification and eutrophication of wilderness ecosystems. Planktonic communities have shown declines in response to predation and shifts in composition as a result of nutrient inputs and acidification, both of which are potential fates of nitrogen deposition. This study identified the response of zooplankton communities from two lakes (fish present vs. absent) in Mount Rainier National Park to manipulations simulating an episodic disturbance event in mesocosms. The experiment used a 2 x 2 factorial design with acid and nitrogen treatments. Treatments resulted in significantly elevated nitrogen and decreased pH conditions from control mesocosms over 42 days, indicating that the treatment effects were achieved. Results indicate that zooplankton communities from lakes with different food web structure respond differently to the singular effects of acid and nitrogen addition. Surprisingly, the interaction of the two stressors was related to increases in community metrics (e.g., abundance, biomass, body size, richness, and Shannon-Weiner diversity) for both lake types. This work can aid management decisions as agencies look to restore more aquatic montane habitats to their historic fishless states, and assess their abilities to recover and afford resistance to atmospheric pollution. Title: The Response of Zooplankton Communities in Montane Lakes of Different Fish Stocking Histories to Atmospheric Nitrogen Deposition Simulations Author: Brittain, Jeffrey Thomas Year: 2015 Freshwater ecosystems are subject to a wide variety of stressors, which can have complex interactions and result in ecological surprises. Non-native fish introductions have drastically reduced the number of naturally fishless lakes and have resulted in cascading food web repercussions in aquatic and terrestrial habitats. Additional anthropogenic influences that result from increases in global airborne emissions also threaten wildlife habitat. Atmospheric nitrogen deposition has been recognized as an anthropogenic contributor to acidification and eutrophication of wilderness ecosystems. Planktonic communities have shown declines in response to predation and shifts in composition as a result of nutrient inputs and acidification, both of which are potential fates of nitrogen deposition. This study identified the response of zooplankton communities from two lakes (fish present vs. absent) in Mount Rainier National Park to manipulations simulating an episodic disturbance event in mesocosms. The experiment used a 2 x 2 factorial design with acid and nitrogen treatments. Treatments resulted in significantly elevated nitrogen and decreased pH conditions from control mesocosms over 42 days, indicating that the treatment effects were achieved. Results indicate that zooplankton communities from lakes with different food web structure respond differently to the singular effects of acid and nitrogen addition. Surprisingly, the interaction of the two stressors was related to increases in community metrics (e.g., abundance, biomass, body size, richness, and Shannon-Weiner diversity) for both lake types. This work can aid management decisions as agencies look to restore more aquatic montane habitats to their historic fishless states, and assess their abilities to recover and afford resistance to atmospheric pollution. Close

• 32. [Article] Oregon's Fish and Wildlife in a Changing Climate

  Chapter 7 in: The Oregon Climate Change Assessment Report Oregon's fish and wildlife include animals on land, fish and other species in rivers and lakes, and various kinds of sea life in estuaries and ...

  Citation × Citation Citation Abstract Copy Title: Oregon's Fish and Wildlife in a Changing Climate Author: Hixon, Mark A., Gregory, Stanley V., Robinson, W. Douglas, Baker, C. Scott, Batchelder, Harold P., Epps, Clinton, Garcia, Tiffany S., Haig, Susan M., Letelier, Ricardo M., Lytle, David A., Menge, Bruce A., Miller, Jeffery C., Noakes, David L.G., Peterson, William T., Rice, James M., Rumrill, Steven S., Schreck, Carl B., Suryan, Robert M., Sytsma, Mark D., White, Angelicque E. Year: 2010 Chapter 7 in: The Oregon Climate Change Assessment Report Oregon's fish and wildlife include animals on land, fish and other species in rivers and lakes, and various kinds of sea life in estuaries and coastal ocean. Oregon is one of the most ecologically diverse states in the country. The state’s robust biodiversity, some of which is already threatened or endangered -- inhabits complex and dynamic ecosystems that we have only begun to understand, let alone examine in terms of climate change.It is clear that the abundance and distribution of species are shifting already and will shift more rapidly as habitats on land, in freshwater, and in the sea are altered due to increasing temperatures and related environmental changes. It remains to be seen if past changes are all tied to global climate change or if they are a result of some other variability, but they represent a proxy for how species may shift in a warmer climate. Among the observed species changes: Insects are moving in from the south of Oregon, frogs are reproducing earlier in the year and land birds are shifting their distributions northward and migrating earlier. Freshwater fish are losing their cool-water habitats. In the marine environment, algal blooms have increased (figure 11) and the highly predatory Humboldt squid have shifted their distribution from subtropical and tropical regions, making an appearance off the coast of Oregon in the last few years. In a warmer climate, plant and animal species may have to shift upward or northward on land or deeper at sea for survival. Rare or endangered species may become less abundant or extinct; insect pests, invasive species and harmful algal blooms may become more abundant. Declines in the abundance of species may be caused directly by physiological stress related to changes in temperature, water availability, and other environmental shifts, and/or indirectly by habitat degradation and negative interactions with species that are benefited by climate change (diseases, parasites, predators, and competitors). Understanding the responses of Oregon’s fish and wildlife to climate change will require a better understanding of smaller organisms and insects and ocean species. Knowledge of ecological interactions will be crucial for understanding the related effects of climate change (increased predation or competition, for example). Management and natural resource polices that protect intact ecosystems are a tool for adaptation; native species can live and migrate to these safe refugia. Title: Oregon's Fish and Wildlife in a Changing Climate Author: Hixon, Mark A., Gregory, Stanley V., Robinson, W. Douglas, Baker, C. Scott, Batchelder, Harold P., Epps, Clinton, Garcia, Tiffany S., Haig, Susan M., Letelier, Ricardo M., Lytle, David A., Menge, Bruce A., Miller, Jeffery C., Noakes, David L.G., Peterson, William T., Rice, James M., Rumrill, Steven S., Schreck, Carl B., Suryan, Robert M., Sytsma, Mark D., White, Angelicque E. Year: 2010 Chapter 7 in: The Oregon Climate Change Assessment Report Oregon's fish and wildlife include animals on land, fish and other species in rivers and lakes, and various kinds of sea life in estuaries and coastal ocean. Oregon is one of the most ecologically diverse states in the country. The state’s robust biodiversity, some of which is already threatened or endangered -- inhabits complex and dynamic ecosystems that we have only begun to understand, let alone examine in terms of climate change.It is clear that the abundance and distribution of species are shifting already and will shift more rapidly as habitats on land, in freshwater, and in the sea are altered due to increasing temperatures and related environmental changes. It remains to be seen if past changes are all tied to global climate change or if they are a result of some other variability, but they represent a proxy for how species may shift in a warmer climate. Among the observed species changes: Insects are moving in from the south of Oregon, frogs are reproducing earlier in the year and land birds are shifting their distributions northward and migrating earlier. Freshwater fish are losing their cool-water habitats. In the marine environment, algal blooms have increased (figure 11) and the highly predatory Humboldt squid have shifted their distribution from subtropical and tropical regions, making an appearance off the coast of Oregon in the last few years. In a warmer climate, plant and animal species may have to shift upward or northward on land or deeper at sea for survival. Rare or endangered species may become less abundant or extinct; insect pests, invasive species and harmful algal blooms may become more abundant. Declines in the abundance of species may be caused directly by physiological stress related to changes in temperature, water availability, and other environmental shifts, and/or indirectly by habitat degradation and negative interactions with species that are benefited by climate change (diseases, parasites, predators, and competitors). Understanding the responses of Oregon’s fish and wildlife to climate change will require a better understanding of smaller organisms and insects and ocean species. Knowledge of ecological interactions will be crucial for understanding the related effects of climate change (increased predation or competition, for example). Management and natural resource polices that protect intact ecosystems are a tool for adaptation; native species can live and migrate to these safe refugia. Close

• 33. [Article] Spatial and Temporal Variability of Contaminants Within Estuarine Sediments and Native Olympia Oysters: A Contrast Between a Developed and an Undeveloped Estuary

  Chemical contaminants can be introduced into estuarine and marine ecosystems from a variety of sources including wastewater, agriculture and forestry practices, point and non-point discharges, runoff from ...

  Citation × Citation Citation Abstract Copy Title: Spatial and Temporal Variability of Contaminants Within Estuarine Sediments and Native Olympia Oysters: A Contrast Between a Developed and an Undeveloped Estuary Author: Granek, Elise F., Conn, Katherine E., Nilsen, Elena B., Pillsbury, Lori, Strecker, Angela L., Rumrill, Steven S., Fish, William Year: 2016 Chemical contaminants can be introduced into estuarine and marine ecosystems from a variety of sources including wastewater, agriculture and forestry practices, point and non-point discharges, runoff from industrial, municipal, and urban lands, accidental spills, and atmospheric deposition. The diversity of potential sources contributes to the likelihood of contaminated marine waters and sediments and increases the probability of uptake by marine organisms. Despite widespread recognition of direct and indirect pathways for contaminant deposition and organismal exposure in coastal systems, spatial and temporal variability in contaminant composition, deposition, and uptake patterns are still poorly known. We investigated these patterns for a suite of persistent legacy contaminants including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) and chemicals of emerging concern including pharmaceuticals within two Oregon coastal estuaries (Coos and Netarts Bays). In the more urbanized Coos Bay, native Olympia oyster (Ostrea lurida) tissue had approximately twice the number of PCB congeners at over seven times the total concentration, yet fewer PBDEs at one-tenth the concentration as compared to the more rural Netarts Bay. Different pharmaceutical suites were detected during each sampling season. Variability in contaminant types and concentrations across seasons and between species and media (organisms versus sediment) indicates the limitation of using indicator species and/or sampling annually to determine contaminant loads at a site or for specific species. The results indicate the prevalence of legacy contaminants and CECs in relatively undeveloped coastal environments highlighting the need to improve policy and management actions to reduce contaminant releases into estuarine and marine waters and to deal with legacy compounds that remain long after prohibition of use. Our results point to the need for better understanding of the ecological and human health risks of exposure to the diverse cocktail of pollutants and harmful compounds that will continue to leach from estuarine sediments over time. Title: Spatial and Temporal Variability of Contaminants Within Estuarine Sediments and Native Olympia Oysters: A Contrast Between a Developed and an Undeveloped Estuary Author: Granek, Elise F., Conn, Katherine E., Nilsen, Elena B., Pillsbury, Lori, Strecker, Angela L., Rumrill, Steven S., Fish, William Year: 2016 Chemical contaminants can be introduced into estuarine and marine ecosystems from a variety of sources including wastewater, agriculture and forestry practices, point and non-point discharges, runoff from industrial, municipal, and urban lands, accidental spills, and atmospheric deposition. The diversity of potential sources contributes to the likelihood of contaminated marine waters and sediments and increases the probability of uptake by marine organisms. Despite widespread recognition of direct and indirect pathways for contaminant deposition and organismal exposure in coastal systems, spatial and temporal variability in contaminant composition, deposition, and uptake patterns are still poorly known. We investigated these patterns for a suite of persistent legacy contaminants including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) and chemicals of emerging concern including pharmaceuticals within two Oregon coastal estuaries (Coos and Netarts Bays). In the more urbanized Coos Bay, native Olympia oyster (Ostrea lurida) tissue had approximately twice the number of PCB congeners at over seven times the total concentration, yet fewer PBDEs at one-tenth the concentration as compared to the more rural Netarts Bay. Different pharmaceutical suites were detected during each sampling season. Variability in contaminant types and concentrations across seasons and between species and media (organisms versus sediment) indicates the limitation of using indicator species and/or sampling annually to determine contaminant loads at a site or for specific species. The results indicate the prevalence of legacy contaminants and CECs in relatively undeveloped coastal environments highlighting the need to improve policy and management actions to reduce contaminant releases into estuarine and marine waters and to deal with legacy compounds that remain long after prohibition of use. Our results point to the need for better understanding of the ecological and human health risks of exposure to the diverse cocktail of pollutants and harmful compounds that will continue to leach from estuarine sediments over time. Close

• 34. [Article] Climate-Suitable Planting as a Strategy for Maintaining Forest Productivity and Functional Diversity

  Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity ...

  Citation × Citation Citation Abstract Copy Title: Climate-Suitable Planting as a Strategy for Maintaining Forest Productivity and Functional Diversity Author: Duveneck, Matthew Joshua, Scheller, Robert M. Year: 2015 Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity in forests under current management and climate change. We evaluated the efficacy of planting climate-suitable tree species (CSP), those tree species with current or historic distributions immediately south of a focal landscape, to maintain or increase aboveground biomass, productivity, and species and functional diversity. We modeled forest change with the LANDIS-II forest simulation model for 100 years (2000–2100) at a 2-ha cell resolution and five-year time steps within two landscapes in the Great Lakes region (northeastern Minnesota and northern lower Michigan, USA). We compared current climate to low- and high-emission futures. We simulated a low-emission climate future with the Intergovernmental Panel on Climate Change (IPCC) 2007 B1 emission scenario and the Parallel Climate Model Global Circulation Model (GCM). We simulated a high-emission climate future with the IPCC A1FI emission scenario and the Geophysical Fluid Dynamics Laboratory (GFDL) GCM. We compared current forest management practices (business-asusual) to CSP management. In the CSP scenario, we simulated a target planting of 5.28% and 4.97% of forested area per five-year time step in the Minnesota and Michigan landscapes, respectively. We found that simulated CSP species successfully established in both landscapes under all climate scenarios. The presence of CSP species generally increased simulated aboveground biomass. Species diversity increased due to CSP; however, the effect on functional diversity was variable. Because the planted species were functionally similar to many native species, CSP did not result in a consistent increase nor decrease in functional diversity. These results provide an assessment of the potential efficacy and limitations of CSP management. These results have management implications for sites where diversity and productivity are expected to decline. Future efforts to restore a specific species or forest type may not be possible, but CSP may sustain a more general ecosystem service (e.g., aboveground biomass). Title: Climate-Suitable Planting as a Strategy for Maintaining Forest Productivity and Functional Diversity Author: Duveneck, Matthew Joshua, Scheller, Robert M. Year: 2015 Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity in forests under current management and climate change. We evaluated the efficacy of planting climate-suitable tree species (CSP), those tree species with current or historic distributions immediately south of a focal landscape, to maintain or increase aboveground biomass, productivity, and species and functional diversity. We modeled forest change with the LANDIS-II forest simulation model for 100 years (2000–2100) at a 2-ha cell resolution and five-year time steps within two landscapes in the Great Lakes region (northeastern Minnesota and northern lower Michigan, USA). We compared current climate to low- and high-emission futures. We simulated a low-emission climate future with the Intergovernmental Panel on Climate Change (IPCC) 2007 B1 emission scenario and the Parallel Climate Model Global Circulation Model (GCM). We simulated a high-emission climate future with the IPCC A1FI emission scenario and the Geophysical Fluid Dynamics Laboratory (GFDL) GCM. We compared current forest management practices (business-asusual) to CSP management. In the CSP scenario, we simulated a target planting of 5.28% and 4.97% of forested area per five-year time step in the Minnesota and Michigan landscapes, respectively. We found that simulated CSP species successfully established in both landscapes under all climate scenarios. The presence of CSP species generally increased simulated aboveground biomass. Species diversity increased due to CSP; however, the effect on functional diversity was variable. Because the planted species were functionally similar to many native species, CSP did not result in a consistent increase nor decrease in functional diversity. These results provide an assessment of the potential efficacy and limitations of CSP management. These results have management implications for sites where diversity and productivity are expected to decline. Future efforts to restore a specific species or forest type may not be possible, but CSP may sustain a more general ecosystem service (e.g., aboveground biomass). Close