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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] Gwinnett County Parks and Recreation - Invasive Plant Species Management Plan

  2016

  Citation × Citation Citation Abstract Copy Title: Gwinnett County Parks and Recreation - Invasive Plant Species Management Plan Author: Patterson, Mark Andre 2016 Title: Gwinnett County Parks and Recreation - Invasive Plant Species Management Plan Author: Patterson, Mark Andre 2016 Close

• 4. [Article] Bio-Economic Modelling of the Red King Crab Invasion in the Barents Sea

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Bio-Economic Modelling of the Red King Crab Invasion in the Barents Sea Author: Armstrong, Claire, Falk-Petersen, Jannike Abstract only. Title: Bio-Economic Modelling of the Red King Crab Invasion in the Barents Sea Author: Armstrong, Claire, Falk-Petersen, Jannike Abstract only. Close

• 5. [Article] Resilience to Stress and Disturbance, and Resistance to Bromus tectorum L. Invasion in Cold Desert Shrublands of Western North America

  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 Springer ...

  Citation × Citation Citation Abstract Copy Title: Resilience to Stress and Disturbance, and Resistance to Bromus tectorum L. Invasion in Cold Desert Shrublands of Western North America Author: Miller, Richard F., Germino, Matthew J., Grace, James B., D'Antonio, Carla, Brown, Cynthia S., Bradley, Bethany A., Hardegree, Stuart P., Pyke, David A., Chambers, Jeanne C. 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 Springer and can be found at: http://link.springer.com/journal/10021. Title: Resilience to Stress and Disturbance, and Resistance to Bromus tectorum L. Invasion in Cold Desert Shrublands of Western North America Author: Miller, Richard F., Germino, Matthew J., Grace, James B., D'Antonio, Carla, Brown, Cynthia S., Bradley, Bethany A., Hardegree, Stuart P., Pyke, David A., Chambers, Jeanne C. 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 Springer and can be found at: http://link.springer.com/journal/10021. Close

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

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

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

• 7. [Article] Willamette Valley prairie restoration : the Native Seed Network and Sidalcea

  My internship was conducted with the Native Seed Network program within the Institute for Applied Ecology, a non-profit organization located in Corvallis, whose focus is education, applied research and ...

  Citation × Citation Citation Abstract Copy Title: Willamette Valley prairie restoration : the Native Seed Network and Sidalcea Author: Lambert, Joshua K. My internship was conducted with the Native Seed Network program within the Institute for Applied Ecology, a non-profit organization located in Corvallis, whose focus is education, applied research and active restoration and of native ecosystems. My internship goals were to increase my experience in applied restoration ecology and conservation biology with the emphasis on native plant communities in particular the endangered prairie communities of the Willamette Valley. These goals were met through my tenure with the Native Seed Network’s native seed collection and increase program during the 2007 field season. This work provided me strong experience with a process necessary for genetically conservative restoration and provided the NSN with a willing intern to complete their goals for 2007. Additional work I accomplished included a morphometric analysis of the native Willamette Valley prairie forb Sidalcea campestris which served as one constituent towards resolving the general ambiguity of this focal species for prairie restoration. Included in this analysis is a presentation and my interpretation of an initial molecular phylogenetic analysis on a selection of S. campestris accessions by Liston and deFeniks (unpublished) that may aid in the future resolution of S. campestris and other congeners in the Willamette Valley. The purpose of the morphological research was not mastery of population genetics or statistics but an exercise in concentration and achievement towards a more integrated and advanced application of taxonomic work oriented towards preserving biological diversity. This entire report completes the written requirement for the Professional Science Masters degree in Applied Systematic through the Botany and Plant Pathology Department at Oregon State University. Title: Willamette Valley prairie restoration : the Native Seed Network and Sidalcea Author: Lambert, Joshua K. My internship was conducted with the Native Seed Network program within the Institute for Applied Ecology, a non-profit organization located in Corvallis, whose focus is education, applied research and active restoration and of native ecosystems. My internship goals were to increase my experience in applied restoration ecology and conservation biology with the emphasis on native plant communities in particular the endangered prairie communities of the Willamette Valley. These goals were met through my tenure with the Native Seed Network’s native seed collection and increase program during the 2007 field season. This work provided me strong experience with a process necessary for genetically conservative restoration and provided the NSN with a willing intern to complete their goals for 2007. Additional work I accomplished included a morphometric analysis of the native Willamette Valley prairie forb Sidalcea campestris which served as one constituent towards resolving the general ambiguity of this focal species for prairie restoration. Included in this analysis is a presentation and my interpretation of an initial molecular phylogenetic analysis on a selection of S. campestris accessions by Liston and deFeniks (unpublished) that may aid in the future resolution of S. campestris and other congeners in the Willamette Valley. The purpose of the morphological research was not mastery of population genetics or statistics but an exercise in concentration and achievement towards a more integrated and advanced application of taxonomic work oriented towards preserving biological diversity. This entire report completes the written requirement for the Professional Science Masters degree in Applied Systematic through the Botany and Plant Pathology Department at Oregon State University. Close

• 8. [Article] Food systems in the Marys River region and reinhabitation

  Reinhabitation is an approach to building local cultures and economies within industrial society. The food system is a vital starting point. What are the principles of reinhabitory food systems? What are ...

  Citation × Citation Citation Abstract Copy Title: Food systems in the Marys River region and reinhabitation Author: Burke, Erik P. Reinhabitation is an approach to building local cultures and economies within industrial society. The food system is a vital starting point. What are the principles of reinhabitory food systems? What are the possibilities for a locally adapted food system in the Marys River region of western Oregon? I describe past and present food systems in the region and give recommendations for building a reinhabitory food system. Native people established locally adapted food systems in the Marys River region and maintained them for thousands of years, culminating in the Kalapuyan food system that existed at Euroamerican contact. Euroamericans began to settle in the region in 1845, and immediately began to domesticate the landscape, replacing native ecosystems with cropland and pasture. By 1900, a diversified food system had emerged with several locally adapted characteristics. The industrial food system replaced the diversified food system during World War II, and has dominated since then. Locally adapted elements of food systems were rapidly abandoned. Industrialism emphasized mass production of export crops using fossil fuels, heavy machinery, and agrichemicals. A large variety of cultural, economic, and ecological problems emerged, and the health of natural and human communities was diminished. Reinhabitation is a positive response to the problems of industrial food systems. A locally adapted food system in the Marys River region is possible. There is enough agricultural land to feed the population. A small but growing segment of the local population has established alternative food systems, and initiated the process of building a regional food system. Reviewing the history of the Marys River region helps clarify how to apply principles of reinhabitation in the region. Title: Food systems in the Marys River region and reinhabitation Author: Burke, Erik P. Reinhabitation is an approach to building local cultures and economies within industrial society. The food system is a vital starting point. What are the principles of reinhabitory food systems? What are the possibilities for a locally adapted food system in the Marys River region of western Oregon? I describe past and present food systems in the region and give recommendations for building a reinhabitory food system. Native people established locally adapted food systems in the Marys River region and maintained them for thousands of years, culminating in the Kalapuyan food system that existed at Euroamerican contact. Euroamericans began to settle in the region in 1845, and immediately began to domesticate the landscape, replacing native ecosystems with cropland and pasture. By 1900, a diversified food system had emerged with several locally adapted characteristics. The industrial food system replaced the diversified food system during World War II, and has dominated since then. Locally adapted elements of food systems were rapidly abandoned. Industrialism emphasized mass production of export crops using fossil fuels, heavy machinery, and agrichemicals. A large variety of cultural, economic, and ecological problems emerged, and the health of natural and human communities was diminished. Reinhabitation is a positive response to the problems of industrial food systems. A locally adapted food system in the Marys River region is possible. There is enough agricultural land to feed the population. A small but growing segment of the local population has established alternative food systems, and initiated the process of building a regional food system. Reviewing the history of the Marys River region helps clarify how to apply principles of reinhabitation in the region. Close

• 9. [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

• 10. [Article] Linking removal targets to the ecological effects of invaders: a predictive model and field test

  Species invasions have a range of negative effects on recipient ecosystems, and many occur at a scale and magnitude that preclude complete eradication. When complete extirpation is unlikely with available ...

  Citation × Citation Citation Abstract Copy Title: Linking removal targets to the ecological effects of invaders: a predictive model and field test Author: Brooks, Annabelle L. M., Côté, Isabelle M., Miller, Skylar, Green, Stephanie J., Dulvy, Nicholas K., Cooper, Andrew B., Akins, John L. Species invasions have a range of negative effects on recipient ecosystems, and many occur at a scale and magnitude that preclude complete eradication. When complete extirpation is unlikely with available management resources, an effective strategy may be to suppress invasive populations below levels predicted to cause undesirable ecological change. We illustrate this approach by developing and testing targets for the control of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) on Western Atlantic coral reefs. We first developed a size structured simulation model of predation by lionfish on native fish communities, which we used to predict threshold densities of lionfish beyond which native fish biomass should decline. We then tested our predictions by experimentally manipulating lionfish densities above or below reef-specific thresholds, and monitoring the consequences for native fish populations on 24 Bahamian patch reefs over 18 months. We found that reducing lionfish below predicted threshold densities effectively protected native fish community biomass from predation-induced declines. Reductions in density of 75- 95%, depending on the reef, were required to suppress lionfish below levels predicted to over-consume prey. On reefs where lionfish were kept threshold densities, native prey fish biomass increased by 50-70%. Gains in small (<6cm) size classes of native fishes translated into lagged increases in larger size classes over time. The biomass of larger individuals (>15cm total length), including ecologically important grazers and economically important fisheries species, had increased by 10-65% by the end of the experiment. Crucially, similar gains in prey fish biomass were realized on reefs subjected to partial and full removal of lionfish, but partial removals took 30% less time to implement. By contrast, the biomass of small native fishes declined by more than 50% on all reefs with lionfish densities exceeding reef-specific thresholds. Large inter-reef variation in the biomass of prey fishes at the outset of the study, which influences the threshold density of lionfish, means that we identify a single rule-of-thumb for guiding control efforts. However, our model provides a method for setting reef-specific targets for population control using local monitoring data. Our work is the first to demonstrate that for ongoing invasions, suppressing invaders below densitiesterms of protecting the native ecosystem on a local scale, to achieving complete eradication Title: Linking removal targets to the ecological effects of invaders: a predictive model and field test Author: Brooks, Annabelle L. M., Côté, Isabelle M., Miller, Skylar, Green, Stephanie J., Dulvy, Nicholas K., Cooper, Andrew B., Akins, John L. Species invasions have a range of negative effects on recipient ecosystems, and many occur at a scale and magnitude that preclude complete eradication. When complete extirpation is unlikely with available management resources, an effective strategy may be to suppress invasive populations below levels predicted to cause undesirable ecological change. We illustrate this approach by developing and testing targets for the control of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) on Western Atlantic coral reefs. We first developed a size structured simulation model of predation by lionfish on native fish communities, which we used to predict threshold densities of lionfish beyond which native fish biomass should decline. We then tested our predictions by experimentally manipulating lionfish densities above or below reef-specific thresholds, and monitoring the consequences for native fish populations on 24 Bahamian patch reefs over 18 months. We found that reducing lionfish below predicted threshold densities effectively protected native fish community biomass from predation-induced declines. Reductions in density of 75- 95%, depending on the reef, were required to suppress lionfish below levels predicted to over-consume prey. On reefs where lionfish were kept threshold densities, native prey fish biomass increased by 50-70%. Gains in small (<6cm) size classes of native fishes translated into lagged increases in larger size classes over time. The biomass of larger individuals (>15cm total length), including ecologically important grazers and economically important fisheries species, had increased by 10-65% by the end of the experiment. Crucially, similar gains in prey fish biomass were realized on reefs subjected to partial and full removal of lionfish, but partial removals took 30% less time to implement. By contrast, the biomass of small native fishes declined by more than 50% on all reefs with lionfish densities exceeding reef-specific thresholds. Large inter-reef variation in the biomass of prey fishes at the outset of the study, which influences the threshold density of lionfish, means that we identify a single rule-of-thumb for guiding control efforts. However, our model provides a method for setting reef-specific targets for population control using local monitoring data. Our work is the first to demonstrate that for ongoing invasions, suppressing invaders below densitiesterms of protecting the native ecosystem on a local scale, to achieving complete eradication Close