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• 131. [Article] The Distribution and Abundance of a Non-native Eelgrass, Zostera japonica, in Oregon Estuaries

  Senior Thesis Bachelor of Science Degree April 2006 Major professor=Sylvia Yamada

  Citation × Citation Citation Abstract Copy Title: The Distribution and Abundance of a Non-native Eelgrass, Zostera japonica, in Oregon Estuaries Author: Dudoit, Chana Makale’a Senior Thesis Bachelor of Science Degree April 2006 Major professor=Sylvia Yamada Title: The Distribution and Abundance of a Non-native Eelgrass, Zostera japonica, in Oregon Estuaries Author: Dudoit, Chana Makale’a Senior Thesis Bachelor of Science Degree April 2006 Major professor=Sylvia Yamada Close

• 132. [Article] Native and exotic plant cover vary inversely along a climate gradient 11 years following stand-replacing wildfire in a dry coniferous forest, Oregon, USA

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by John Wiley & Sons, Ltd., and can be found at: http://onlinelibrary.wiley.com/jo...

  Citation × Citation Citation Abstract Copy Title: Native and exotic plant cover vary inversely along a climate gradient 11 years following stand-replacing wildfire in a dry coniferous forest, Oregon, USA Author: Root, Heather T., Dodson, Erich K. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by John Wiley & Sons, Ltd., and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2486 Title: Native and exotic plant cover vary inversely along a climate gradient 11 years following stand-replacing wildfire in a dry coniferous forest, Oregon, USA Author: Root, Heather T., Dodson, Erich K. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by John Wiley & Sons, Ltd., and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2486 Close

• 133. [Image] An assessment of ecosystem components in the interior Columbia Basin and portions of the Klamath and Great Basins [volume 1]

  	Quigley, Thomas M.; Arbelbide, Sylvia J., tech. eds. 1997. An assessment of ecosystem components in the interior Columbia basin and portions of the Klamath and Great Basins: volume 1. Gen. Tech. Rep. PNW-GTR-405. ...
  	Citation × Citation Citation Abstract Copy Title: An assessment of ecosystem components in the interior Columbia Basin and portions of the Klamath and Great Basins [volume 1] Author: Quigley, Thomas Milton; Arbelbide, S. J. (Sylvia J.) Year: 1997, 2008, 2005 Quigley, Thomas M.; Arbelbide, Sylvia J., tech. eds. 1997. An assessment of ecosystem components in the interior Columbia basin and portions of the Klamath and Great Basins: volume 1. Gen. Tech. Rep. PNW-GTR-405. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 4 vol. (Quigley, Thomas M., tech. ed.; The Interior Columbia Basin Ecosystem Management Project: Scientific Assessment). The Assessment of Ecosystem Components in the Interior Columbia Basin and Portions of the Klamath and Great Basins provides detailed information about current conditions and trends for the biophysical and social systems within the Basin. This information can be used by land managers to develop broad land management goals and priorities and provides the context for decisions specific to smaller geographic areas. The Assessment area covers about 8 percent of the U.S. land area, 24 percent of the Nation's National Forest System lands, 10 percent of the Nation's BLM-administered lands, and contains about 1.2 percent of the Nation's population. This results in a population density that is less than one-sixth of the U.S. average. The area has experienced recent, rapid population growth and generally has a robust, diverse economy. As compared to historic conditions, the terrestrial, aquatic, forest, and rangeland systems have undergone dramatic changes. Forested landscapes are more susceptible to fire, insect, and disease than under historic conditions. Rangelands are highly susceptible to noxious weed invasion. The disturbance regimes that operate on forest and rangeland have changed substantially, with lethal fires dominating many areas where non-lethal fires were the norm historically. Terrestrial habitats that have experienced the greatest decline include the native grassland, native shrubland, and old forest structures. There are areas within the Assessment area that have higher diversity than others. Aquatic systems are now more fragmented and isolated than historically and the introduction of non-native fish species has complicated current status of native fishes. Core habitat and population centers do remain as building blocks for restoration. Social and economic conditions within the Assessment area vary considerably, depending to a great extent on population, diversity of employment opportunities, and changing demographics. Those counties with the higher population densities and greater diversity of employment opportunities are generally more resilient to economic downturns. This Assessment provides a rich information base, including over 170 mapped themes with associated models and databases, from which future decisions can benefit. Keywords: Columbia basin, biophysical systems, social systems, ecosystem. Title: An assessment of ecosystem components in the interior Columbia Basin and portions of the Klamath and Great Basins [volume 1] Author: Quigley, Thomas Milton; Arbelbide, S. J. (Sylvia J.) Year: 1997, 2008, 2005 Quigley, Thomas M.; Arbelbide, Sylvia J., tech. eds. 1997. An assessment of ecosystem components in the interior Columbia basin and portions of the Klamath and Great Basins: volume 1. Gen. Tech. Rep. PNW-GTR-405. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 4 vol. (Quigley, Thomas M., tech. ed.; The Interior Columbia Basin Ecosystem Management Project: Scientific Assessment). The Assessment of Ecosystem Components in the Interior Columbia Basin and Portions of the Klamath and Great Basins provides detailed information about current conditions and trends for the biophysical and social systems within the Basin. This information can be used by land managers to develop broad land management goals and priorities and provides the context for decisions specific to smaller geographic areas. The Assessment area covers about 8 percent of the U.S. land area, 24 percent of the Nation's National Forest System lands, 10 percent of the Nation's BLM-administered lands, and contains about 1.2 percent of the Nation's population. This results in a population density that is less than one-sixth of the U.S. average. The area has experienced recent, rapid population growth and generally has a robust, diverse economy. As compared to historic conditions, the terrestrial, aquatic, forest, and rangeland systems have undergone dramatic changes. Forested landscapes are more susceptible to fire, insect, and disease than under historic conditions. Rangelands are highly susceptible to noxious weed invasion. The disturbance regimes that operate on forest and rangeland have changed substantially, with lethal fires dominating many areas where non-lethal fires were the norm historically. Terrestrial habitats that have experienced the greatest decline include the native grassland, native shrubland, and old forest structures. There are areas within the Assessment area that have higher diversity than others. Aquatic systems are now more fragmented and isolated than historically and the introduction of non-native fish species has complicated current status of native fishes. Core habitat and population centers do remain as building blocks for restoration. Social and economic conditions within the Assessment area vary considerably, depending to a great extent on population, diversity of employment opportunities, and changing demographics. Those counties with the higher population densities and greater diversity of employment opportunities are generally more resilient to economic downturns. This Assessment provides a rich information base, including over 170 mapped themes with associated models and databases, from which future decisions can benefit. Keywords: Columbia basin, biophysical systems, social systems, ecosystem. Close

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

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

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

• 135. [Article] Castilleja and Pedicularis are confirmed as telial hosts for white pine blister rust in whitebark pine ecosystems of Oregon and Washington

  The primary objective of this research was to determine if native species within the genera Castilleja and Pedicularis are naturally infected by white pine blister rust (Cronartium ribicola) in whitebark ...

  Citation × Citation Citation Abstract Copy Title: Castilleja and Pedicularis are confirmed as telial hosts for white pine blister rust in whitebark pine ecosystems of Oregon and Washington Author: Mulvey, Robin L. The primary objective of this research was to determine if native species within the genera Castilleja and Pedicularis are naturally infected by white pine blister rust (Cronartium ribicola) in whitebark pine ecosystems of the Oregon and Washington Cascade Range. Secondary objectives were to monitor the phenology of aecial and telial hosts to determine if there is sufficient time for C. ribicola to complete its lifecycle within high-elevation stands, and to evaluate the extent and variety of susceptible native hosts within these genera through field and growth chamber inoculation. These objectives were approached through fieldwork in 2008 and 2009 in whitebark pine ecosystems at Mt. Rainier, Mt. Adams, Mt. Hood, Mt. Bachelor, Tumalo Mtn. and Crater Lake. Forty-nine observational study plots were established (28 in 2008 and 21 in 2009) and monitored three to six times per season. Natural C. ribicola infection was detected on 84 Pedicularis racemosa plants and five Castilleja plants (C. applegatei, C. miniata, and C. parviflora). Field observations provided evidence that there is sufficient time for C. ribicola to complete its lifecycle on hosts within high-elevation whitebark pine stands. In 2009, 18 field inoculation plots were established at Mt. Rainier and Crater Lake. Field inoculation confirmed the susceptibility of two additional species within these genera, C. arachnoidea and P. bracteosa. The species identity of the rust on field specimens was verified through PCR and genetic sequencing of the ITS1-5.8S-ITS2 region of DNA. All four Castilleja species inoculated in the growth chamber developed infection, with an overall infection incidence of 62% (167 out of 270 plants). Improved understanding of the role of these newly recognized hosts in white pine blister rust epidemiology should be used to prioritize sites for the restoration of ecologically-valuable whitebark pine. Title: Castilleja and Pedicularis are confirmed as telial hosts for white pine blister rust in whitebark pine ecosystems of Oregon and Washington Author: Mulvey, Robin L. The primary objective of this research was to determine if native species within the genera Castilleja and Pedicularis are naturally infected by white pine blister rust (Cronartium ribicola) in whitebark pine ecosystems of the Oregon and Washington Cascade Range. Secondary objectives were to monitor the phenology of aecial and telial hosts to determine if there is sufficient time for C. ribicola to complete its lifecycle within high-elevation stands, and to evaluate the extent and variety of susceptible native hosts within these genera through field and growth chamber inoculation. These objectives were approached through fieldwork in 2008 and 2009 in whitebark pine ecosystems at Mt. Rainier, Mt. Adams, Mt. Hood, Mt. Bachelor, Tumalo Mtn. and Crater Lake. Forty-nine observational study plots were established (28 in 2008 and 21 in 2009) and monitored three to six times per season. Natural C. ribicola infection was detected on 84 Pedicularis racemosa plants and five Castilleja plants (C. applegatei, C. miniata, and C. parviflora). Field observations provided evidence that there is sufficient time for C. ribicola to complete its lifecycle on hosts within high-elevation whitebark pine stands. In 2009, 18 field inoculation plots were established at Mt. Rainier and Crater Lake. Field inoculation confirmed the susceptibility of two additional species within these genera, C. arachnoidea and P. bracteosa. The species identity of the rust on field specimens was verified through PCR and genetic sequencing of the ITS1-5.8S-ITS2 region of DNA. All four Castilleja species inoculated in the growth chamber developed infection, with an overall infection incidence of 62% (167 out of 270 plants). Improved understanding of the role of these newly recognized hosts in white pine blister rust epidemiology should be used to prioritize sites for the restoration of ecologically-valuable whitebark pine. Close

• 136. [Article] Impacts of instream flows on the Colorado River Delta, Mexico : spatial vegetation change analysis and opportunities for restoration

  Until the 1930s, flows of the Colorado River maintained approximately 781,060 hectares of wetlands in its delta. These wetlands provided important feeding and nesting grounds for resident and migratory ...

  Citation × Citation Citation Abstract Copy Title: Impacts of instream flows on the Colorado River Delta, Mexico : spatial vegetation change analysis and opportunities for restoration Author: Zamora-Arroyo, Jose Francisco Until the 1930s, flows of the Colorado River maintained approximately 781,060 hectares of wetlands in its delta. These wetlands provided important feeding and nesting grounds for resident and migratory birds as well as spawning and protection habitat for many fish and other invertebrate species. However, the Delta's wetlands started to disappear as water was used for agricultural and urban uses in the United States and Mexico. The 1944 United States-Mexico water treaty, which allocates 1.8 million m³/year to Mexico, did not define a minimum flow to maintain the Delta's ecosystems. The resulting degraded Delta lead to the perception in the 1980s that the Delta was a dead ecosystem. This study investigates whether this "dead Delta" perception is valid. Its central hypothesis is that regenerated vegetation in riparian and flood plain zones is associated with surplus river flows during the 1990s. A vegetation analysis, using satellite imagery and field methods, shows that native trees have regenerated during the last 20 years, and now account for 23% of vegetation in a 100 km, non-perennial, stretch of river below the United States-Mexico border. A spatial trend analysis using multi-temporal data on percent vegetation cover indicates that there are 6,320 hectares that show a significant increasing trend (p-value<0.05) in vegetation cover, with the Delta's riparian zone having at least 18% of its area showing this trend. The study estimates that once in four years February to April flow of 300 million m³ (at 80-120 m³/s) is sufficient to germinate and establish new cohorts of native trees, and highlights the need for smaller but more periodic flows in order to maintain wetland areas. It is concluded that there is clear evidence of the resilience of the Delta's ecosystems and that the "dead Delta" perception is no longer valid. There exist critical habitat in the Delta that needs to be protected, while there also exist short and long term opportunities to ecologically enhance and expand current habitat. Hydrological and ecological studies are needed to estimate specific water requirements for these areas in order to efficiently target them for immediate and long term conservation actions. Title: Impacts of instream flows on the Colorado River Delta, Mexico : spatial vegetation change analysis and opportunities for restoration Author: Zamora-Arroyo, Jose Francisco Until the 1930s, flows of the Colorado River maintained approximately 781,060 hectares of wetlands in its delta. These wetlands provided important feeding and nesting grounds for resident and migratory birds as well as spawning and protection habitat for many fish and other invertebrate species. However, the Delta's wetlands started to disappear as water was used for agricultural and urban uses in the United States and Mexico. The 1944 United States-Mexico water treaty, which allocates 1.8 million m³/year to Mexico, did not define a minimum flow to maintain the Delta's ecosystems. The resulting degraded Delta lead to the perception in the 1980s that the Delta was a dead ecosystem. This study investigates whether this "dead Delta" perception is valid. Its central hypothesis is that regenerated vegetation in riparian and flood plain zones is associated with surplus river flows during the 1990s. A vegetation analysis, using satellite imagery and field methods, shows that native trees have regenerated during the last 20 years, and now account for 23% of vegetation in a 100 km, non-perennial, stretch of river below the United States-Mexico border. A spatial trend analysis using multi-temporal data on percent vegetation cover indicates that there are 6,320 hectares that show a significant increasing trend (p-value<0.05) in vegetation cover, with the Delta's riparian zone having at least 18% of its area showing this trend. The study estimates that once in four years February to April flow of 300 million m³ (at 80-120 m³/s) is sufficient to germinate and establish new cohorts of native trees, and highlights the need for smaller but more periodic flows in order to maintain wetland areas. It is concluded that there is clear evidence of the resilience of the Delta's ecosystems and that the "dead Delta" perception is no longer valid. There exist critical habitat in the Delta that needs to be protected, while there also exist short and long term opportunities to ecologically enhance and expand current habitat. Hydrological and ecological studies are needed to estimate specific water requirements for these areas in order to efficiently target them for immediate and long term conservation actions. Close

• 137. [Article] Ecophysiology of Marine Bivalves : Physiological Rate Processes in Dynamic Environments

  Marine bivalves are globally recognized as ecologically and commercially valuable species and, for over a century, researchers have been studying their feeding, digestion and other related physiological ...

  Citation × Citation Citation Abstract Copy Title: Ecophysiology of Marine Bivalves : Physiological Rate Processes in Dynamic Environments Author: Gray, Matthew W. Marine bivalves are globally recognized as ecologically and commercially valuable species and, for over a century, researchers have been studying their feeding, digestion and other related physiological processes. These studies have shown that marine bivalves have complex feeding and particle processing behaviors to maximize growth in dynamic environmental conditions. Additionally, these studies have provided insights into the ecological roles that these animals can play in coastal waters. Suspension-feeding bivalves are commonly regarded as providing key ecosystem services through their feeding activities that improve water quality and clarity. However, marine bivalves are currently under threat from a variety of anthropogenic effects and there is concern about their future health under these new stresses. Here I examined several unexplored aspects of adult and larval bivalve feeding physiology in an attempt to better understand environmental effects on their feeding activity and ecosystem services. In Chapter 2, my co-authors and I examined the ecological feeding physiology of native Olympia oysters Ostrea lurida by determining their feeding and particle processing behavior in response to the effects of temperature, salinity, and total particulate matter. We examined and compared these processes to those of the non-native yet dominant commercial oyster species, the Pacific oyster Crassostrea gigas. From these studies, we describe the first modern detailed feeding behavior of O. lurida. We found that, although markedly different in laboratory studies, in situ feeding rates were similar between these species seasonally. We concluded that bivalve filtration services are likely to be greater with the emergence of C. gigas as the now dominant species in many PNW estuaries and seasonally much greater than the services historically contributed by O. lurida. In Chapters 3, my co-authors and I examined the particle processing behavior of bivalve larvae. This study was novel in that it utilized methods of our own design to examine the rarely evaluated post-oral particle processing behavior of larvae that historically has been difficult to measure. Additionally, it represented the first attempt at modeling larval guts as chemical reactors to provide insights into their digestive strategies. In Chapter 4, we again applied these novel techniques to evaluate the effects of ocean acidification on ingestion rates and particle processing of larvae of the California mussel Mytilus californianus. These data were applied to a simple larval energy budget to understand how impacts of ocean acidification on initial larval development may affect their subsequent development rates. The outcomes of these experiments provide useful information on feeding and particle processing activities of the adult and larval life stages of marine bivalves and the effects of environmental factors, such as ocean acidification. Title: Ecophysiology of Marine Bivalves : Physiological Rate Processes in Dynamic Environments Author: Gray, Matthew W. Marine bivalves are globally recognized as ecologically and commercially valuable species and, for over a century, researchers have been studying their feeding, digestion and other related physiological processes. These studies have shown that marine bivalves have complex feeding and particle processing behaviors to maximize growth in dynamic environmental conditions. Additionally, these studies have provided insights into the ecological roles that these animals can play in coastal waters. Suspension-feeding bivalves are commonly regarded as providing key ecosystem services through their feeding activities that improve water quality and clarity. However, marine bivalves are currently under threat from a variety of anthropogenic effects and there is concern about their future health under these new stresses. Here I examined several unexplored aspects of adult and larval bivalve feeding physiology in an attempt to better understand environmental effects on their feeding activity and ecosystem services. In Chapter 2, my co-authors and I examined the ecological feeding physiology of native Olympia oysters Ostrea lurida by determining their feeding and particle processing behavior in response to the effects of temperature, salinity, and total particulate matter. We examined and compared these processes to those of the non-native yet dominant commercial oyster species, the Pacific oyster Crassostrea gigas. From these studies, we describe the first modern detailed feeding behavior of O. lurida. We found that, although markedly different in laboratory studies, in situ feeding rates were similar between these species seasonally. We concluded that bivalve filtration services are likely to be greater with the emergence of C. gigas as the now dominant species in many PNW estuaries and seasonally much greater than the services historically contributed by O. lurida. In Chapters 3, my co-authors and I examined the particle processing behavior of bivalve larvae. This study was novel in that it utilized methods of our own design to examine the rarely evaluated post-oral particle processing behavior of larvae that historically has been difficult to measure. Additionally, it represented the first attempt at modeling larval guts as chemical reactors to provide insights into their digestive strategies. In Chapter 4, we again applied these novel techniques to evaluate the effects of ocean acidification on ingestion rates and particle processing of larvae of the California mussel Mytilus californianus. These data were applied to a simple larval energy budget to understand how impacts of ocean acidification on initial larval development may affect their subsequent development rates. The outcomes of these experiments provide useful information on feeding and particle processing activities of the adult and larval life stages of marine bivalves and the effects of environmental factors, such as ocean acidification. Close

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

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

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

• 139. [Article] Thermal controls of Yellowstone cutthroat trout and invasive fishes under climate change

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. The published article is copyrighted by Wiley-Blackwell and can be found at: http:...

  Citation × Citation Citation Abstract Copy Title: Thermal controls of Yellowstone cutthroat trout and invasive fishes under climate change Author: Hostetler, Steven, Gresswell, Robert, Alder, Jay R., Shepard, Bradley, Al-Chokhachy, Robert To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. The published article is copyrighted by Wiley-Blackwell and can be found at: http://onlinelibrary.wiley.com/. Title: Thermal controls of Yellowstone cutthroat trout and invasive fishes under climate change Author: Hostetler, Steven, Gresswell, Robert, Alder, Jay R., Shepard, Bradley, Al-Chokhachy, Robert To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. The published article is copyrighted by Wiley-Blackwell and can be found at: http://onlinelibrary.wiley.com/. Close

• 140. [Article] Sugar application and nitrogen pools in Wyoming big sagebrush communities and exotic annual grasslands

  Within A rtemisia tridentata ssp. wyomingensis Nutt. (Wyoming big sagebrush) communities of the Great Basin, lands dominated by the exotic annual grass Bromus tectorum L. (cheatgrass) are increasing at ...

  Citation × Citation Citation Abstract Copy Title: Sugar application and nitrogen pools in Wyoming big sagebrush communities and exotic annual grasslands Author: Witwicki, Dana L. Within A rtemisia tridentata ssp. wyomingensis Nutt. (Wyoming big sagebrush) communities of the Great Basin, lands dominated by the exotic annual grass Bromus tectorum L. (cheatgrass) are increasing at an alarming rate. Carbon applications, which reduce plant-available soil N, have been suggested as a way to give native vegetation a competitive advantage over exotic annual grasses when reseeding after a fire. The main objectives of my study were to 1) compare N pools in intact A. tridentata- and B. tectorum-dominated communities to look for evidence of ecosystem changes associated with annual grass invasion, and 2) quantify and compare the effects of sugar and nitrogen additions on N pools in each of these communities. Research occurred at six sites in eastern Oregon and southwestern Idaho, each containing pairs of A. tridentata and exotic annual grass communities in close proximity. Pairs were carefully selected with similar soil types, precipitation, elevation, aspect, slope and ecological sites (i.e. potential vegetation and production). At the beginning of the cheatgrass growing season (late fall), three treatments (sugar, nitrogen or control) were applied. For soil pools, only one difference between untreated plots of annual and native communities was detected. In autumn. NO3 in the native community was about two-thirds the level in the annual community. The sugar treatment decreased inorganic N to near undetectable levels one week after application, and levels remained low six months later (during peak B. tectorum biomass). Although the sugar treatment did not increase microbial biomass N from chloroform fumigation extraction, we found higher '5N in microbial biomass and soil organic matter, suggesting that more N remained in the microbial pooi over the growing season. The reduction of aboveground plant biomass by sugar and the increase of aboveground plant biomass from nitrogen addition were more pronounced for B. tectorum than for native plants. Plant responses indicated that treatment with labile carbon like sugar may be useful tools for restoration of native plants and for prevention of B. tectorum dominance, but additional research is necessary to quantify dose responses of B. tectorum to sugar. Title: Sugar application and nitrogen pools in Wyoming big sagebrush communities and exotic annual grasslands Author: Witwicki, Dana L. Within A rtemisia tridentata ssp. wyomingensis Nutt. (Wyoming big sagebrush) communities of the Great Basin, lands dominated by the exotic annual grass Bromus tectorum L. (cheatgrass) are increasing at an alarming rate. Carbon applications, which reduce plant-available soil N, have been suggested as a way to give native vegetation a competitive advantage over exotic annual grasses when reseeding after a fire. The main objectives of my study were to 1) compare N pools in intact A. tridentata- and B. tectorum-dominated communities to look for evidence of ecosystem changes associated with annual grass invasion, and 2) quantify and compare the effects of sugar and nitrogen additions on N pools in each of these communities. Research occurred at six sites in eastern Oregon and southwestern Idaho, each containing pairs of A. tridentata and exotic annual grass communities in close proximity. Pairs were carefully selected with similar soil types, precipitation, elevation, aspect, slope and ecological sites (i.e. potential vegetation and production). At the beginning of the cheatgrass growing season (late fall), three treatments (sugar, nitrogen or control) were applied. For soil pools, only one difference between untreated plots of annual and native communities was detected. In autumn. NO3 in the native community was about two-thirds the level in the annual community. The sugar treatment decreased inorganic N to near undetectable levels one week after application, and levels remained low six months later (during peak B. tectorum biomass). Although the sugar treatment did not increase microbial biomass N from chloroform fumigation extraction, we found higher '5N in microbial biomass and soil organic matter, suggesting that more N remained in the microbial pooi over the growing season. The reduction of aboveground plant biomass by sugar and the increase of aboveground plant biomass from nitrogen addition were more pronounced for B. tectorum than for native plants. Plant responses indicated that treatment with labile carbon like sugar may be useful tools for restoration of native plants and for prevention of B. tectorum dominance, but additional research is necessary to quantify dose responses of B. tectorum to sugar. Close