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• 1. [Article] Invasive mammal eradication on islands results in substantial conservation gains

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the National ...

  Citation × Citation Citation Abstract Copy Title: Invasive mammal eradication on islands results in substantial conservation gains Author: Howald, Gregg R., Miskelly, Colin M., Burbidge, Andrew A., Campbell, Karl, Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Courchamp, Franck, Jones, Holly P., Keitt, Bradford S., Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Spatz, Dena R., Genovesi, Piero, Armstrong, Doug P., Holmes, Nick D., Croll, Donald A., Bonnaud, Elsa, Towns, David R., Poncet, Sally, Rocamora, Gérard To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the National Academy of Sciences and can be found at: http://www.pnas.org/ Title: Invasive mammal eradication on islands results in substantial conservation gains Author: Howald, Gregg R., Miskelly, Colin M., Burbidge, Andrew A., Campbell, Karl, Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Courchamp, Franck, Jones, Holly P., Keitt, Bradford S., Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Spatz, Dena R., Genovesi, Piero, Armstrong, Doug P., Holmes, Nick D., Croll, Donald A., Bonnaud, Elsa, Towns, David R., Poncet, Sally, Rocamora, Gérard To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the National Academy of Sciences and can be found at: http://www.pnas.org/ Close

• 2. [Article] JonesInvasiveMammalEradication.pdf

  Citation × Citation Citation Abstract Copy Title: JonesInvasiveMammalEradication.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Campbell, Karl, Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Towns, David R., Jones, Holly P., Keitt, Bradford S., Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Spatz, Dena R., Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Croll, Donald A., Bonnaud, Elsa, Courchamp, Franck, Poncet, Sally, Rocamora, Gérard Title: JonesInvasiveMammalEradication.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Campbell, Karl, Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Towns, David R., Jones, Holly P., Keitt, Bradford S., Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Spatz, Dena R., Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Croll, Donald A., Bonnaud, Elsa, Courchamp, Franck, Poncet, Sally, Rocamora, Gérard Close

• 3. [Article] JonesInvasiveMammalEradicationTable1.pdf

  Citation × Citation Citation Abstract Copy Title: JonesInvasiveMammalEradicationTable1.pdf Author: Howald, Gregg R., Armstrong, Doug P., Burbidge, Andrew A., Campbell, Karl, Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Bonnaud, Elsa, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Courchamp, Franck, Jones, Holly P., Keitt, Bradford S., Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Spatz, Dena R., Genovesi, Piero, Miskelly, Colin M., Holmes, Nick D., Croll, Donald A., Ebbert, Steve, Towns, David R., Poncet, Sally, Rocamora, Gérard Title: JonesInvasiveMammalEradicationTable1.pdf Author: Howald, Gregg R., Armstrong, Doug P., Burbidge, Andrew A., Campbell, Karl, Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Bonnaud, Elsa, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Courchamp, Franck, Jones, Holly P., Keitt, Bradford S., Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Spatz, Dena R., Genovesi, Piero, Miskelly, Colin M., Holmes, Nick D., Croll, Donald A., Ebbert, Steve, Towns, David R., Poncet, Sally, Rocamora, Gérard Close

• 4. [Article] JonesInvasiveMammalEradicationTable2.pdf

  Citation × Citation Citation Abstract Copy Title: JonesInvasiveMammalEradicationTable2.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Campbell, Karl, Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Courchamp, Franck, Jones, Holly P., Poncet, Sally, Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Rocamora, Gérard, Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Croll, Donald A., Bonnaud, Elsa, Towns, David R., Keitt, Bradford S., Spatz, Dena R. Title: JonesInvasiveMammalEradicationTable2.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Campbell, Karl, Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Courchamp, Franck, Jones, Holly P., Poncet, Sally, Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Rocamora, Gérard, Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Croll, Donald A., Bonnaud, Elsa, Towns, David R., Keitt, Bradford S., Spatz, Dena R. Close

• 5. [Article] JonesInvasiveMammalEradicationTable3.pdf

  Citation × Citation Citation Abstract Copy Title: JonesInvasiveMammalEradicationTable3.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Croll, Donald A., Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Towns, David R., Jones, Holly P., Keitt, Bradford S., Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Spatz, Dena R., Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Campbell, Karl, Bonnaud, Elsa, Courchamp, Franck, Poncet, Sally, Rocamora, Gérard Title: JonesInvasiveMammalEradicationTable3.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Croll, Donald A., Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Towns, David R., Jones, Holly P., Keitt, Bradford S., Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Spatz, Dena R., Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Campbell, Karl, Bonnaud, Elsa, Courchamp, Franck, Poncet, Sally, Rocamora, Gérard Close

• 6. [Article] JonesInvasiveMammalEradicationTable4.pdf

  Citation × Citation Citation Abstract Copy Title: JonesInvasiveMammalEradicationTable4.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Croll, Donald A., Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Bonnaud, Elsa, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Towns, David R., Jones, Holly P., Poncet, Sally, Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Rocamora, Gérard, Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Campbell, Karl, Ebbert, Steve, Courchamp, Franck, Keitt, Bradford S., Spatz, Dena R. Title: JonesInvasiveMammalEradicationTable4.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Croll, Donald A., Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Bonnaud, Elsa, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Towns, David R., Jones, Holly P., Poncet, Sally, Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Rocamora, Gérard, Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Campbell, Karl, Ebbert, Steve, Courchamp, Franck, Keitt, Bradford S., Spatz, Dena R. Close

• 7. [Article] JonesInvasiveMammalEradicationTable5.pdf

  Citation × Citation Citation Abstract Copy Title: JonesInvasiveMammalEradicationTable5.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Croll, Donald A., Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Courchamp, Franck, Jones, Holly P., Poncet, Sally, Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Rocamora, Gérard, Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Campbell, Karl, Bonnaud, Elsa, Towns, David R., Keitt, Bradford S., Spatz, Dena R. Title: JonesInvasiveMammalEradicationTable5.pdf Author: Genovesi, Piero, Armstrong, Doug P., Burbidge, Andrew A., Croll, Donald A., Rauzon, Mark J., Cowan, Philip E., Seddon, Philip J., Corkery, Ilse, Ebbert, Steve, Oppel, Steffen, Kappes, Peter J., Butchart, Stuart H. M., Courchamp, Franck, Jones, Holly P., Poncet, Sally, Russell, James C., Tershy, Bernie R., Kress, Stephen W., Samaniego-Herrera, Araceli, Cuthbert, Richard J., Aguirre-Muñoz, Alfonso, Rocamora, Gérard, Howald, Gregg R., Miskelly, Colin M., Holmes, Nick D., Campbell, Karl, Bonnaud, Elsa, Towns, David R., Keitt, Bradford S., Spatz, Dena R. Close

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

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

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

• 9. [Article] Plant community dynamics in remnant and restored Willamette Valley wetland prairies

  Invasion by exotic species can pose a major challenge for developing native plant communities in wetland restoration projects. Often native plant communities do not develop as anticipated in restored wetlands ...

  Citation × Citation Citation Abstract Copy Title: Plant community dynamics in remnant and restored Willamette Valley wetland prairies Author: Schwindt, Rachel A. Invasion by exotic species can pose a major challenge for developing native plant communities in wetland restoration projects. Often native plant communities do not develop as anticipated in restored wetlands due to colonization by exotic species that dominate the native plant community. Despite the time and expense to restore wetlands, there has been little long term research to compare plant communities in restored and natural wetland sites. Research into plant community diversity across several wetland sites over several years can provide a broader perspective into how these ecosystems recover from long-term disturbance. The objective of this study was to compare plant community change from 2000 to 2005 between restored and remnant wetland prairie sites in the southern Willamette Valley in Oregon to determine if exotic species abundance was consistent between these groups. Specific objectives included 1) comparing the diversity and abundance of all species in remnant and restored wetland prairie sites, 2) evaluate the trajectory of community change between remnant and restored wetland prairie sites to determine if there was rapid change in restored sites, and 3) describe the plot level heterogeneity of the plant community in all sites to determine how microsites influence diversity. In 2005, species abundance was re-measured in four remnant wetland prairies and four restored wetland prairies that had been selected for an unrelated vegetation survey in 2000. Species were characterized by life form, origin, and wetland indicator status. Species abundance between groups of remnant and restored sites were compared using a multi-response permutation procedure (MRPP). The plant community trajectory was evaluated with nonmetric multidimensional scaling (NMS) and tested for significance with multivariate analysis of variance (MANOVA). Species area curves were compared between sites and within remnant and restored groups of plots. Within-year and between-year significance tests indicated that remnant and restored sites were similar in exotic species abundance, graminoid abundance, and wetland species abundance with no significant difference between these remnant and restored wetland prairie sites. Individual sites in both groups experienced changes in exotic species abundance which confounded the statistical results. Species heterogeneity was no more spatially diverse across the remnant site plots than restored site plots. Species area curves did not show significant differences between remnant and restored plots but individual plots did show homogeneous community characteristics at smaller spatial scales. Restoration sites had developed high graminoid cover by the 2000 survey which was conducted two to three years after restoration was initiated. All sites were equally likely to contain exotic species. Exotic species common across all sites included Centaurium umbellatum, Holcus lanatus, and Hypericum perforatum. Native species common across sites included Deschampsia cespitosa, Danthonia californica and Juncus tenuis. These results suggested that differences between remnant and restored Willamette Valley wetland prairie sites were not generalizable at the landscape scale and were more dependent on site specific management activities and local barriers to colonization. Five years may not be enough time to see evidence that suggests if restored plant communities will develop spatial characteristics of the remnant sites. This research does suggest that multi-site comparisons help distinguish individual sites that are not developing characteristics of remnant wetland plant communities. Title: Plant community dynamics in remnant and restored Willamette Valley wetland prairies Author: Schwindt, Rachel A. Invasion by exotic species can pose a major challenge for developing native plant communities in wetland restoration projects. Often native plant communities do not develop as anticipated in restored wetlands due to colonization by exotic species that dominate the native plant community. Despite the time and expense to restore wetlands, there has been little long term research to compare plant communities in restored and natural wetland sites. Research into plant community diversity across several wetland sites over several years can provide a broader perspective into how these ecosystems recover from long-term disturbance. The objective of this study was to compare plant community change from 2000 to 2005 between restored and remnant wetland prairie sites in the southern Willamette Valley in Oregon to determine if exotic species abundance was consistent between these groups. Specific objectives included 1) comparing the diversity and abundance of all species in remnant and restored wetland prairie sites, 2) evaluate the trajectory of community change between remnant and restored wetland prairie sites to determine if there was rapid change in restored sites, and 3) describe the plot level heterogeneity of the plant community in all sites to determine how microsites influence diversity. In 2005, species abundance was re-measured in four remnant wetland prairies and four restored wetland prairies that had been selected for an unrelated vegetation survey in 2000. Species were characterized by life form, origin, and wetland indicator status. Species abundance between groups of remnant and restored sites were compared using a multi-response permutation procedure (MRPP). The plant community trajectory was evaluated with nonmetric multidimensional scaling (NMS) and tested for significance with multivariate analysis of variance (MANOVA). Species area curves were compared between sites and within remnant and restored groups of plots. Within-year and between-year significance tests indicated that remnant and restored sites were similar in exotic species abundance, graminoid abundance, and wetland species abundance with no significant difference between these remnant and restored wetland prairie sites. Individual sites in both groups experienced changes in exotic species abundance which confounded the statistical results. Species heterogeneity was no more spatially diverse across the remnant site plots than restored site plots. Species area curves did not show significant differences between remnant and restored plots but individual plots did show homogeneous community characteristics at smaller spatial scales. Restoration sites had developed high graminoid cover by the 2000 survey which was conducted two to three years after restoration was initiated. All sites were equally likely to contain exotic species. Exotic species common across all sites included Centaurium umbellatum, Holcus lanatus, and Hypericum perforatum. Native species common across sites included Deschampsia cespitosa, Danthonia californica and Juncus tenuis. These results suggested that differences between remnant and restored Willamette Valley wetland prairie sites were not generalizable at the landscape scale and were more dependent on site specific management activities and local barriers to colonization. Five years may not be enough time to see evidence that suggests if restored plant communities will develop spatial characteristics of the remnant sites. This research does suggest that multi-site comparisons help distinguish individual sites that are not developing characteristics of remnant wetland plant communities. Close

• 10. [Article] Restoring the Columbia River Estuary : Chinook Salmon Recovery and Invasive Species Management

  As highlighted in this study, shallow-water habitats and the prey they provide are important for juvenile salmon in the Columbia River estuary, but the spread of invasive species and large-scale changes ...

  Citation × Citation Citation Abstract Copy Title: Restoring the Columbia River Estuary : Chinook Salmon Recovery and Invasive Species Management Author: Klopfenstein, Rachael As highlighted in this study, shallow-water habitats and the prey they provide are important for juvenile salmon in the Columbia River estuary, but the spread of invasive species and large-scale changes to the estuary influence how these habitats are utilized. Reed canarygrass (Phalaris arundinacea) (“PHAR” hereafter) is a highly invasive aquatic plant species that affects a number of emergent wetland habitats in the upper Columbia River estuary, and is of concern to those trying to restore important shallow-water habitats for juvenile salmon. The presence of PHAR undoubtedly reduces plant diversity, but this study seeked to elucidate how PHAR affects juvenile Chinook Salmon rearing success relative to natural emergent vegetation. The study further evaluated the importance of wetland-deriver prey to juveniles found in shallow-water habitats along a habitat gradient (i.e., back-water channel, confluence, and main stem). We conducted research at a floodplain wetland restoration site in the tidal-fluvial portion of the estuary, where a water control structure is used to manage water levels and the spread of PHAR. The goal of the research was to compare two microhabitats within the floodplain: areas dominated by PHAR and areas dominated by natural emergent vegetation. Using hatchery-raised juvenile Chinook salmon, we designed a series of feeding experiments in artificial enclosures to determine whether invasive PHAR and natural emergent vegetation provide similar foraging and growth opportunities for juvenile salmon. We further identified differences in physical and biological parameters of each habitat (e.g., temperature, dissolved oxygen, and invertebrate community) and examined feeding characteristics (e.g., diet composition and modeled growth rates) for juveniles through a stomach content analysis. Additionally, we conducted beach seining and diet analysis for fish collected along a habitat gradient and compared the diet composition and modeled growth rates between the sample areas. In the floodplain wetland, invertebrate prey compositions from the 2015-2016 (March- June) fallout and emergence traps were similar, but prey abundances and diversity varied seasonally. Across both years, for emergence traps, the average total density (per m²) of invertebrates in the natural vegetation and in PHAR was 154±18 m² and 225±34 m², respectively, and for the fallout traps was 664±95 m² and 662±64 m², respectively. Salmon diets were mostly similar, and a large proportion of diets in both habitats were made up of Copepoda/Cladocera (60-98% composition by biomass). Growth during the net pen experiment differed significantly between the two vegetation types (Kruskal-Wallis: p<0.001), with fish growing more in the natural emergent vegetation. In 2015, juveniles grew an average 6.4 mm FL in the natural emergent vegetation, compared to 4.7 mm FL in PHAR, and consumed fewer Copepoda/Cladocera and more Diptera over the 10 days. In 2016, juveniles grew an average 9.2 mm FL in the natural emergent vegetation compared to 7.6 mm FL in PHAR. In 2016, fish from both habitats consumed a higher abundance of Copepoda/Cladocera and grew more, despite poor water quality conditions at the site. Of the subyearlings (n=170) and yearlings (n=14) collected in habitats adjacent to the floodplain wetland, 48% were of known hatchery origin. Modeled potential growth rates for subyearlings were similar on average between February and May in the back channel, confluence, and main stem, ranging from 0.067–0.07 g/g/d, but the rates varied seasonally. Growth potential was higher in the back channel habitat earlier in the sampling season (February-March), as the modeled daily growth rates were 0.08 g/g/d compared to 0.06 g/g/d in the main stem. All fish collected prior to May were relatively small and unclipped, highlighting the seasonal benefits of shallow-water habitats to support a variety of life-history traits. When comparing modeled growth rates of the juveniles reared at the floodplain wetland compared to the in adjacent habitats, estimates from the floodplain wetland were higher across all months. Restoration of shallow-water habitats is important for the overall health of the estuary, but the effects of large-scale ecosystem changes (e.g., flow regulation and spread invasive species) on salmon recovery and estuary-management decisions are uncertain. For example, water control structures to limit the spread of PHAR also reduce fish access to floodplain habitats, and fewer high-flow events further limit fish access and may facilitate the spread of invasive species. PHAR has been shown to reduce overall plant diversity and, as observed in this study, may provide habitat that is less suitable to juvenile Chinook Salmon. The high density of important prey for salmon found at the site, regardless of the presence of PHAR, and high potential growth measured at the site, emphasize the importance of restoring shallow-water habitats that are accessible to juvenile Chinook Salmon in the upper estuary. Title: Restoring the Columbia River Estuary : Chinook Salmon Recovery and Invasive Species Management Author: Klopfenstein, Rachael As highlighted in this study, shallow-water habitats and the prey they provide are important for juvenile salmon in the Columbia River estuary, but the spread of invasive species and large-scale changes to the estuary influence how these habitats are utilized. Reed canarygrass (Phalaris arundinacea) (“PHAR” hereafter) is a highly invasive aquatic plant species that affects a number of emergent wetland habitats in the upper Columbia River estuary, and is of concern to those trying to restore important shallow-water habitats for juvenile salmon. The presence of PHAR undoubtedly reduces plant diversity, but this study seeked to elucidate how PHAR affects juvenile Chinook Salmon rearing success relative to natural emergent vegetation. The study further evaluated the importance of wetland-deriver prey to juveniles found in shallow-water habitats along a habitat gradient (i.e., back-water channel, confluence, and main stem). We conducted research at a floodplain wetland restoration site in the tidal-fluvial portion of the estuary, where a water control structure is used to manage water levels and the spread of PHAR. The goal of the research was to compare two microhabitats within the floodplain: areas dominated by PHAR and areas dominated by natural emergent vegetation. Using hatchery-raised juvenile Chinook salmon, we designed a series of feeding experiments in artificial enclosures to determine whether invasive PHAR and natural emergent vegetation provide similar foraging and growth opportunities for juvenile salmon. We further identified differences in physical and biological parameters of each habitat (e.g., temperature, dissolved oxygen, and invertebrate community) and examined feeding characteristics (e.g., diet composition and modeled growth rates) for juveniles through a stomach content analysis. Additionally, we conducted beach seining and diet analysis for fish collected along a habitat gradient and compared the diet composition and modeled growth rates between the sample areas. In the floodplain wetland, invertebrate prey compositions from the 2015-2016 (March- June) fallout and emergence traps were similar, but prey abundances and diversity varied seasonally. Across both years, for emergence traps, the average total density (per m²) of invertebrates in the natural vegetation and in PHAR was 154±18 m² and 225±34 m², respectively, and for the fallout traps was 664±95 m² and 662±64 m², respectively. Salmon diets were mostly similar, and a large proportion of diets in both habitats were made up of Copepoda/Cladocera (60-98% composition by biomass). Growth during the net pen experiment differed significantly between the two vegetation types (Kruskal-Wallis: p<0.001), with fish growing more in the natural emergent vegetation. In 2015, juveniles grew an average 6.4 mm FL in the natural emergent vegetation, compared to 4.7 mm FL in PHAR, and consumed fewer Copepoda/Cladocera and more Diptera over the 10 days. In 2016, juveniles grew an average 9.2 mm FL in the natural emergent vegetation compared to 7.6 mm FL in PHAR. In 2016, fish from both habitats consumed a higher abundance of Copepoda/Cladocera and grew more, despite poor water quality conditions at the site. Of the subyearlings (n=170) and yearlings (n=14) collected in habitats adjacent to the floodplain wetland, 48% were of known hatchery origin. Modeled potential growth rates for subyearlings were similar on average between February and May in the back channel, confluence, and main stem, ranging from 0.067–0.07 g/g/d, but the rates varied seasonally. Growth potential was higher in the back channel habitat earlier in the sampling season (February-March), as the modeled daily growth rates were 0.08 g/g/d compared to 0.06 g/g/d in the main stem. All fish collected prior to May were relatively small and unclipped, highlighting the seasonal benefits of shallow-water habitats to support a variety of life-history traits. When comparing modeled growth rates of the juveniles reared at the floodplain wetland compared to the in adjacent habitats, estimates from the floodplain wetland were higher across all months. Restoration of shallow-water habitats is important for the overall health of the estuary, but the effects of large-scale ecosystem changes (e.g., flow regulation and spread invasive species) on salmon recovery and estuary-management decisions are uncertain. For example, water control structures to limit the spread of PHAR also reduce fish access to floodplain habitats, and fewer high-flow events further limit fish access and may facilitate the spread of invasive species. PHAR has been shown to reduce overall plant diversity and, as observed in this study, may provide habitat that is less suitable to juvenile Chinook Salmon. The high density of important prey for salmon found at the site, regardless of the presence of PHAR, and high potential growth measured at the site, emphasize the importance of restoring shallow-water habitats that are accessible to juvenile Chinook Salmon in the upper estuary. Close