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• 1. [Article] Dreissenid Mussel Research Priorities Workshop

  Currently, dreissenid mussels have yet to be detected in the northwestern part of the United States and western Canada. Infestation of one of the jurisdictions within the mussel-free Pacific Northwest ...

  Citation × Citation Citation Abstract Copy Title: Dreissenid Mussel Research Priorities Workshop Author: Sytsma, Mark D., Phillips, Stephen, Counihan, Timothy D. Year: 2015 Currently, dreissenid mussels have yet to be detected in the northwestern part of the United States and western Canada. Infestation of one of the jurisdictions within the mussel-free Pacific Northwest would likely have significant economic, soci­etal and environmental implications for the entire region. Understanding the biology and environmental tolerances of dreissenid mussels, and effectiveness of various man­agement strategies, is key to prevention. On November 4-5, 2015, the Aquatic Bioinvasion Research and Policy Institute and the Center for Lakes and Reservoirs at Portland State University, the US Geological Survey, and the Pacific States Marine Fisheries Commission, convened a Dreissenid Mussel Research Priorities Workshop funded by the Great Northern Landscape Conservation Cooperative. The purpose of the workshop was to review dreissenid research priorities in the 2010 Quagga-Zebra Mussel Action Plan for Western U.S. Waters, reassess those priorities, incorporate new information and emerging trends, and develop priorities to strategically focus research efforts on zebra and quagga mussels in the Pacific Northwest and ensure that future research is focused on the highest priorities. It is important to note that there is some repetition among dreissenid research priority categories (e.g., prevention, detection, control, monitoring, and biology). Workshop participants with research experience in dreissenid mussel biology and management were identified by a literature review. State and federal agency managers were also invited to the workshop to ensure relevancy and practicality of the work­shop outcomes. A total of 28 experts (see sidebar) in mussel biology, ecology, and management attended the workshop. Title: Dreissenid Mussel Research Priorities Workshop Author: Sytsma, Mark D., Phillips, Stephen, Counihan, Timothy D. Year: 2015 Currently, dreissenid mussels have yet to be detected in the northwestern part of the United States and western Canada. Infestation of one of the jurisdictions within the mussel-free Pacific Northwest would likely have significant economic, soci­etal and environmental implications for the entire region. Understanding the biology and environmental tolerances of dreissenid mussels, and effectiveness of various man­agement strategies, is key to prevention. On November 4-5, 2015, the Aquatic Bioinvasion Research and Policy Institute and the Center for Lakes and Reservoirs at Portland State University, the US Geological Survey, and the Pacific States Marine Fisheries Commission, convened a Dreissenid Mussel Research Priorities Workshop funded by the Great Northern Landscape Conservation Cooperative. The purpose of the workshop was to review dreissenid research priorities in the 2010 Quagga-Zebra Mussel Action Plan for Western U.S. Waters, reassess those priorities, incorporate new information and emerging trends, and develop priorities to strategically focus research efforts on zebra and quagga mussels in the Pacific Northwest and ensure that future research is focused on the highest priorities. It is important to note that there is some repetition among dreissenid research priority categories (e.g., prevention, detection, control, monitoring, and biology). Workshop participants with research experience in dreissenid mussel biology and management were identified by a literature review. State and federal agency managers were also invited to the workshop to ensure relevancy and practicality of the work­shop outcomes. A total of 28 experts (see sidebar) in mussel biology, ecology, and management attended the workshop. Close

• 2. [Article] Green Crab Control: A Removal Effort in a Shallow Central California Estuary

  Goal: To test the feasibility and effects of locally removing a well-established population of a marine organism with pelagic larvae. Removal of adult European green crabs (Carcinus maenas) from Bodega ...

  Citation × Citation Citation Abstract Copy Title: Green Crab Control: A Removal Effort in a Shallow Central California Estuary Author: Larson, Amy A., de Rivera, C. E., Ruiz, G. M., Grosholz, E. D., Sytsma, Mark D. Year: 2008 Goal: To test the feasibility and effects of locally removing a well-established population of a marine organism with pelagic larvae. Removal of adult European green crabs (Carcinus maenas) from Bodega Harbor as a model system to develop and inform management options for eradication, rapid response, and control of marine invaders. Title: Green Crab Control: A Removal Effort in a Shallow Central California Estuary Author: Larson, Amy A., de Rivera, C. E., Ruiz, G. M., Grosholz, E. D., Sytsma, Mark D. Year: 2008 Goal: To test the feasibility and effects of locally removing a well-established population of a marine organism with pelagic larvae. Removal of adult European green crabs (Carcinus maenas) from Bodega Harbor as a model system to develop and inform management options for eradication, rapid response, and control of marine invaders. Close

• 3. [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

• 4. [Article] Survey of Aquatic Plants in Corps of Engineers Reservoirs

  A survey of aquatic plants in a selected Corps of Engineers reservoirs in Oregon was conducted. Cottage Grove, Dorena, Fern Ridge, Dexter and Willow Creek Reservoirs contained abundant aquatic plants. ...

  Citation × Citation Citation Abstract Copy Title: Survey of Aquatic Plants in Corps of Engineers Reservoirs Author: Walker, Kimberly D., Sytsma, Mark D. Year: 2000 A survey of aquatic plants in a selected Corps of Engineers reservoirs in Oregon was conducted. Cottage Grove, Dorena, Fern Ridge, Dexter and Willow Creek Reservoirs contained abundant aquatic plants. Potamogeton pectinatus and Potamogeton epihydrous were the most common native plant species. Myriophyllum aquaticum and Potamogeton crispus were the most widespread nonnative plants. Species richness in the reservoirs was correlated with trophic status and basin morphology. Shallow reservoirs that included extensive areas of nutrient-rich sediments that were historic flood plain soils supported the greatest biomass and number of species. Mesotrophic reservoirs had lower species diversity. Oligotrophic reservoirs with steep basin morphology, nutrient-poor sediments, and large water level fluctuation did not support aquatic vascular plant populations. An aquatic plant management program should be developed for the reservoirs. The program should focus on preventing introduction and spread of invasive aquatic plants and on rapid response procedures for new infestations. Those reservoirs that currently support aquatic macrophyte communities may be most susceptible to invasion and rapid spread of new introductions, however, even reservoirs that are currently free of aquatic plants may be invaded. Early detection is critical to effective implementation of rapid response procedures for invasive aquatic plant control. Annual survey of the most productive reservoirs is recommended to document introduction of new species. Plant community composition changes during the growing season, and multiple surveys during the growing season are preferred over one-time visits. Management of established populations of invasive species in the reservoirs will be difficult. Where invasive plant abundance is limited in area and number management activities may be implemented to slow dispersal and perhaps eradicate the plants. Integrated pest management procedures should be followed to ensure effective and economical aquatic plant control. Title: Survey of Aquatic Plants in Corps of Engineers Reservoirs Author: Walker, Kimberly D., Sytsma, Mark D. Year: 2000 A survey of aquatic plants in a selected Corps of Engineers reservoirs in Oregon was conducted. Cottage Grove, Dorena, Fern Ridge, Dexter and Willow Creek Reservoirs contained abundant aquatic plants. Potamogeton pectinatus and Potamogeton epihydrous were the most common native plant species. Myriophyllum aquaticum and Potamogeton crispus were the most widespread nonnative plants. Species richness in the reservoirs was correlated with trophic status and basin morphology. Shallow reservoirs that included extensive areas of nutrient-rich sediments that were historic flood plain soils supported the greatest biomass and number of species. Mesotrophic reservoirs had lower species diversity. Oligotrophic reservoirs with steep basin morphology, nutrient-poor sediments, and large water level fluctuation did not support aquatic vascular plant populations. An aquatic plant management program should be developed for the reservoirs. The program should focus on preventing introduction and spread of invasive aquatic plants and on rapid response procedures for new infestations. Those reservoirs that currently support aquatic macrophyte communities may be most susceptible to invasion and rapid spread of new introductions, however, even reservoirs that are currently free of aquatic plants may be invaded. Early detection is critical to effective implementation of rapid response procedures for invasive aquatic plant control. Annual survey of the most productive reservoirs is recommended to document introduction of new species. Plant community composition changes during the growing season, and multiple surveys during the growing season are preferred over one-time visits. Management of established populations of invasive species in the reservoirs will be difficult. Where invasive plant abundance is limited in area and number management activities may be implemented to slow dispersal and perhaps eradicate the plants. Integrated pest management procedures should be followed to ensure effective and economical aquatic plant control. Close

• 5. [Article] Zebra and Quagga Mussel Early-Detection Monitoring in High Risk Oregon Waters 2014

  Zebra and quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively) were not detected by Oregon Department of Fish and Wildlife (ODFW) and Portland State University (PSU) during ...

  Citation × Citation Citation Abstract Copy Title: Zebra and Quagga Mussel Early-Detection Monitoring in High Risk Oregon Waters 2014 Author: Wells, Steve W., Sytsma, Mark D. Year: 2015 Zebra and quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively) were not detected by Oregon Department of Fish and Wildlife (ODFW) and Portland State University (PSU) during their early detection sampling in Oregon water bodies during 2014. Six high-risk Oregon water bodies were sampled for planktonic larvae and adult mussels during the August to September period. A total of 37 plankton samples were collected and over 520,000 liters of reservoir/lake water were filtered through 64-μm mesh nets during plankton sample collection. The greatest sampling effort occurred in Emigrant Lake, Lake Billy Chinook, and Prineville Reservoir but sampling also occurred in Howard Prairie Lake, Upper Klamath Lake, and Applegate Reservoir. Non-native invertebrates and macrophytes were opportunistically collected during Dreissena sampling in 2014. Corbicula fluminea (Asian clam) adults were collected in Upper Klamath Lake. Potamopyrgus antipodarum (New Zealand mud snails) were collected in Lake Billy Chinook. Potamogeton crispus (curly leaf pondweed) was collected in Emigrant Lake, Howard Prairie Lake, Lake Billy Chinook, and Upper Klamath Lake. To the authors’ knowledge, the C. fluminea in Upper Klamath Lake represents the first reported detection for these species in this location. Title: Zebra and Quagga Mussel Early-Detection Monitoring in High Risk Oregon Waters 2014 Author: Wells, Steve W., Sytsma, Mark D. Year: 2015 Zebra and quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively) were not detected by Oregon Department of Fish and Wildlife (ODFW) and Portland State University (PSU) during their early detection sampling in Oregon water bodies during 2014. Six high-risk Oregon water bodies were sampled for planktonic larvae and adult mussels during the August to September period. A total of 37 plankton samples were collected and over 520,000 liters of reservoir/lake water were filtered through 64-μm mesh nets during plankton sample collection. The greatest sampling effort occurred in Emigrant Lake, Lake Billy Chinook, and Prineville Reservoir but sampling also occurred in Howard Prairie Lake, Upper Klamath Lake, and Applegate Reservoir. Non-native invertebrates and macrophytes were opportunistically collected during Dreissena sampling in 2014. Corbicula fluminea (Asian clam) adults were collected in Upper Klamath Lake. Potamopyrgus antipodarum (New Zealand mud snails) were collected in Lake Billy Chinook. Potamogeton crispus (curly leaf pondweed) was collected in Emigrant Lake, Howard Prairie Lake, Lake Billy Chinook, and Upper Klamath Lake. To the authors’ knowledge, the C. fluminea in Upper Klamath Lake represents the first reported detection for these species in this location. Close

• 6. [Article] OSMB Final Report, Task 7: Online Atlas of Oregon Lakes - Aquatic Invasive Species Interface

  In order to educate a broad cross section of the public about Aquatic Invasive Species (AIS) distributions and survey efforts in Oregon’s lakes and reservoirs, database connections were created to display ...

  Citation × Citation Citation Abstract Copy Title: OSMB Final Report, Task 7: Online Atlas of Oregon Lakes - Aquatic Invasive Species Interface Author: Miller, Rich, Sytsma, Mark D. Year: 2014 In order to educate a broad cross section of the public about Aquatic Invasive Species (AIS) distributions and survey efforts in Oregon’s lakes and reservoirs, database connections were created to display AIS information on the Online Atlas of Oregon Lakes (aol.research.pdx.edu/). The connections allowed for the dynamic display of AIS survey records stored in three separate databases: the Center for Lakes and Reservoir’s Oregon Aquatic Plant and Mussel Databases and the iMapInvasives database. AIS survey records collected by the Center for Lakes and Reservoirs were also reported to the iMapInvasives database. Title: OSMB Final Report, Task 7: Online Atlas of Oregon Lakes - Aquatic Invasive Species Interface Author: Miller, Rich, Sytsma, Mark D. Year: 2014 In order to educate a broad cross section of the public about Aquatic Invasive Species (AIS) distributions and survey efforts in Oregon’s lakes and reservoirs, database connections were created to display AIS information on the Online Atlas of Oregon Lakes (aol.research.pdx.edu/). The connections allowed for the dynamic display of AIS survey records stored in three separate databases: the Center for Lakes and Reservoir’s Oregon Aquatic Plant and Mussel Databases and the iMapInvasives database. AIS survey records collected by the Center for Lakes and Reservoirs were also reported to the iMapInvasives database. Close

• 7. [Article] Middle Columbia River Aquatic Nuisance Species Survey

  Aquatic nonindigenous species (ANS) in the middle Columbia and lower Snake rivers were surveyed during the summer of 2006. The project area included eight reservoirs and the free-flowing, Hanford Reach ...

  Citation × Citation Citation Abstract Copy Title: Middle Columbia River Aquatic Nuisance Species Survey Author: Draheim, Robyn, Sytsma, Mark D., Miller, Rich, Cordell, Jeffery Year: 2007 Aquatic nonindigenous species (ANS) in the middle Columbia and lower Snake rivers were surveyed during the summer of 2006. The project area included eight reservoirs and the free-flowing, Hanford Reach on the Columbia River. We also conducted a literature review to create a complete list of ANS for the study area. Title: Middle Columbia River Aquatic Nuisance Species Survey Author: Draheim, Robyn, Sytsma, Mark D., Miller, Rich, Cordell, Jeffery Year: 2007 Aquatic nonindigenous species (ANS) in the middle Columbia and lower Snake rivers were surveyed during the summer of 2006. The project area included eight reservoirs and the free-flowing, Hanford Reach on the Columbia River. We also conducted a literature review to create a complete list of ANS for the study area. Close

• 8. [Article] 2011 Aquatic Weed Surveys in Timothy Lake, Lake Harriet and North Fork Reservoir : final report

  Portland General Electric (PGE) was issued a new license by the Federal Energy Regulatory Commission (FERC) for the continued operation and maintenance of the Clackamas River Hydroelectric Project No. ...

  Citation × Citation Citation Abstract Copy Title: 2011 Aquatic Weed Surveys in Timothy Lake, Lake Harriet and North Fork Reservoir : final report Author: Sytsma, Mark D., Morgan, Vanessa Howard Year: 2011 Portland General Electric (PGE) was issued a new license by the Federal Energy Regulatory Commission (FERC) for the continued operation and maintenance of the Clackamas River Hydroelectric Project No. 2195 (Project) on December 21, 2010. This Project is located on both the lower 16 miles of Oak Grove Fork of the Clackamas River (Oak Grove Fork) and the mainstem of the Clackamas River in Clackamas County, Oregon. The effects of relicensing this Project were addressed in the Final Environmental Impact Statement (FEIS) completed in December 2006 and included the issue of invasive aquatic weed species. The term “aquatic weed” is used here to refer to any non-native aquatic plant species. Surveys of Timothy Lake conducted by Portland State University (PSU) in 1996 and a subsequent survey of Timothy Lake and Lake Harriet in 2004 did not locate any problematic aquatic weed species. However, repeated monitoring is necessary to detect infestations in a timely fashion and, if noxious weeds are present, to allow treatment when weed cover is low and eradication efforts more cost effective. With that aim, PSU conducted aquatic vegetation surveys of Lake Harriet, Timothy Lake, and North Fork Reservoir between August 31 and September 13, 2011. The purpose of these surveys was to detect any populations of aquatic weeds occurring in the lakes while also establishing baseline information reading native aquatic vegetation abundance and distributions in each waterbody. Title: 2011 Aquatic Weed Surveys in Timothy Lake, Lake Harriet and North Fork Reservoir : final report Author: Sytsma, Mark D., Morgan, Vanessa Howard Year: 2011 Portland General Electric (PGE) was issued a new license by the Federal Energy Regulatory Commission (FERC) for the continued operation and maintenance of the Clackamas River Hydroelectric Project No. 2195 (Project) on December 21, 2010. This Project is located on both the lower 16 miles of Oak Grove Fork of the Clackamas River (Oak Grove Fork) and the mainstem of the Clackamas River in Clackamas County, Oregon. The effects of relicensing this Project were addressed in the Final Environmental Impact Statement (FEIS) completed in December 2006 and included the issue of invasive aquatic weed species. The term “aquatic weed” is used here to refer to any non-native aquatic plant species. Surveys of Timothy Lake conducted by Portland State University (PSU) in 1996 and a subsequent survey of Timothy Lake and Lake Harriet in 2004 did not locate any problematic aquatic weed species. However, repeated monitoring is necessary to detect infestations in a timely fashion and, if noxious weeds are present, to allow treatment when weed cover is low and eradication efforts more cost effective. With that aim, PSU conducted aquatic vegetation surveys of Lake Harriet, Timothy Lake, and North Fork Reservoir between August 31 and September 13, 2011. The purpose of these surveys was to detect any populations of aquatic weeds occurring in the lakes while also establishing baseline information reading native aquatic vegetation abundance and distributions in each waterbody. Close

• 9. [Article] Waldo Lake Research in 2003

  This report summarizes the first year of an effort to develop a more complete understanding of the physical, chemical, and biological characteristics that drive the ecological processes of Waldo Lake. ...

  Citation × Citation Citation Abstract Copy Title: Waldo Lake Research in 2003 Author: Sytsma, Mark D., Rueter, John, Petersen, Richard, Koch, Roy, Wells, Scott A., Miller, Rich, Johnson, Laura, Annear, Robert Leslie Year: 2004 This report summarizes the first year of an effort to develop a more complete understanding of the physical, chemical, and biological characteristics that drive the ecological processes of Waldo Lake. Modern limnology recognizes the importance of watershed processes as well as in- lake processes in lake ecosystem functioning. Therefore, the approach included consideration of watershed hydrology and forcing functions that determine hydrodynamics of the system as well physical and chemical factors that may be important in regulating primary production in the lake. Data collected since 1998 was summarized and bathymetry of the basin was mapped using state-of-the-art digital depth sounding and GPS technology. A hypothesis that UV light may play an important role in regulating phytoplankton efficiency was examined in an effort to move toward more hypothesis-driven investigations to elucidate the factors controlling productivity. A Quality Assurance/Quality Control Plan was developed to guide data collection for long-term monitoring of the lake. Lastly, initial steps were made in the development of a model of lake hydrodynamics and primary production to aid in integration of the physical, chemical, and biological data that has been collected on the lake. Title: Waldo Lake Research in 2003 Author: Sytsma, Mark D., Rueter, John, Petersen, Richard, Koch, Roy, Wells, Scott A., Miller, Rich, Johnson, Laura, Annear, Robert Leslie Year: 2004 This report summarizes the first year of an effort to develop a more complete understanding of the physical, chemical, and biological characteristics that drive the ecological processes of Waldo Lake. Modern limnology recognizes the importance of watershed processes as well as in- lake processes in lake ecosystem functioning. Therefore, the approach included consideration of watershed hydrology and forcing functions that determine hydrodynamics of the system as well physical and chemical factors that may be important in regulating primary production in the lake. Data collected since 1998 was summarized and bathymetry of the basin was mapped using state-of-the-art digital depth sounding and GPS technology. A hypothesis that UV light may play an important role in regulating phytoplankton efficiency was examined in an effort to move toward more hypothesis-driven investigations to elucidate the factors controlling productivity. A Quality Assurance/Quality Control Plan was developed to guide data collection for long-term monitoring of the lake. Lastly, initial steps were made in the development of a model of lake hydrodynamics and primary production to aid in integration of the physical, chemical, and biological data that has been collected on the lake. Close

• 10. [Article] Phenotypic Plasticity of Invasive Spartina Densiflora (Poaceae) Along a Broad Latitudinal Gradient on the Pacific Coast of North America

  • Premise of the study: Phenotypic acclimation of individual plants and genetic differentiation by natural selection within invasive populations are two potential mechanisms that may confer fitness advantages ...

  Citation × Citation Citation Abstract Copy Title: Phenotypic Plasticity of Invasive Spartina Densiflora (Poaceae) Along a Broad Latitudinal Gradient on the Pacific Coast of North America Author: Castillo, Jesus M., Grewall, Brenda J., Pickart, Andrea, Bortolus, Alejandro, Pena, Carlos, Figueroa, Enrique, Sytsma, Mark D. Year: 2014 • Premise of the study: Phenotypic acclimation of individual plants and genetic differentiation by natural selection within invasive populations are two potential mechanisms that may confer fitness advantages and allow plants to cope with environmental variation. The invasion of Spartina densiflora across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provides a natural model system to study the potential mechanisms underlying the response of invasive populations to substantial variation in climate and other environmental variables. • Methods: We examined morphological and physiological leaf traits of Spartina densiflora plants in populations from invaded estuarine sites across broad latitudinal and climate gradients along the Pacific west coast of North America and in favorable conditions in a common garden experiment. • Key results: Our results show that key foliar traits varied widely among populations. Most foliar traits measured in the field were lower than would be expected under ideal growing conditions. Photosynthetic pigment concentrations at higher latitudes were lower than those observed at lower latitudes. Greater leaf rolling, reduced leaf lengths, and lower chlorophyll and higher carbon concentrations were observed with anoxic sediments. Lower chlorophyll to carotenoids ratios and reduced nitrogen concentrations were correlated with sediment salinity. Our results suggest that the variations of foliar traits recorded in the field are a plastic phenotypic response that was not sustained under common garden conditions. • Conclusions: Spartina densiflora shows wide differences in its foliar traits in response to environmental heterogeneity in salt marshes, which appears to be the result of phenotypic plasticity rather than genetic differentiation. Title: Phenotypic Plasticity of Invasive Spartina Densiflora (Poaceae) Along a Broad Latitudinal Gradient on the Pacific Coast of North America Author: Castillo, Jesus M., Grewall, Brenda J., Pickart, Andrea, Bortolus, Alejandro, Pena, Carlos, Figueroa, Enrique, Sytsma, Mark D. Year: 2014 • Premise of the study: Phenotypic acclimation of individual plants and genetic differentiation by natural selection within invasive populations are two potential mechanisms that may confer fitness advantages and allow plants to cope with environmental variation. The invasion of Spartina densiflora across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provides a natural model system to study the potential mechanisms underlying the response of invasive populations to substantial variation in climate and other environmental variables. • Methods: We examined morphological and physiological leaf traits of Spartina densiflora plants in populations from invaded estuarine sites across broad latitudinal and climate gradients along the Pacific west coast of North America and in favorable conditions in a common garden experiment. • Key results: Our results show that key foliar traits varied widely among populations. Most foliar traits measured in the field were lower than would be expected under ideal growing conditions. Photosynthetic pigment concentrations at higher latitudes were lower than those observed at lower latitudes. Greater leaf rolling, reduced leaf lengths, and lower chlorophyll and higher carbon concentrations were observed with anoxic sediments. Lower chlorophyll to carotenoids ratios and reduced nitrogen concentrations were correlated with sediment salinity. Our results suggest that the variations of foliar traits recorded in the field are a plastic phenotypic response that was not sustained under common garden conditions. • Conclusions: Spartina densiflora shows wide differences in its foliar traits in response to environmental heterogeneity in salt marshes, which appears to be the result of phenotypic plasticity rather than genetic differentiation. Close