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• 21. [Article] Development and Initial Application of Low-Molecular Weight Organic Acids and Inorganic Ionic Species in Aerosol Particulate Matter via Ion Chromatography

  Air pollution, especially particulate matter, is a widespread environmental and public health risk. In this work, a method has been developed to separate, resolve, and quantitate monovalent anionic and ...

  Citation × Citation Citation Abstract Copy Title: Development and Initial Application of Low-Molecular Weight Organic Acids and Inorganic Ionic Species in Aerosol Particulate Matter via Ion Chromatography Author: Karpinski, Clarissa D. Year: 2015 Air pollution, especially particulate matter, is a widespread environmental and public health risk. In this work, a method has been developed to separate, resolve, and quantitate monovalent anionic and cationic organic acids in aerosol particulate matter through ion chromatography (IC). The standard samples were analyzed on a Dionex ICS-5000 Ion Chromatography System with suppressed conductivity detection, and calibration curves for all analytes were created. A preliminary tobacco smoke sample was also analyzed. This method may be applied to the analysis of atmospheric particulate matter, as well as tobacco smoke particulate matter, in order to determine and quantitate primary anions and cations. Title: Development and Initial Application of Low-Molecular Weight Organic Acids and Inorganic Ionic Species in Aerosol Particulate Matter via Ion Chromatography Author: Karpinski, Clarissa D. Year: 2015 Air pollution, especially particulate matter, is a widespread environmental and public health risk. In this work, a method has been developed to separate, resolve, and quantitate monovalent anionic and cationic organic acids in aerosol particulate matter through ion chromatography (IC). The standard samples were analyzed on a Dionex ICS-5000 Ion Chromatography System with suppressed conductivity detection, and calibration curves for all analytes were created. A preliminary tobacco smoke sample was also analyzed. This method may be applied to the analysis of atmospheric particulate matter, as well as tobacco smoke particulate matter, in order to determine and quantitate primary anions and cations. Close

• 22. [Article] Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA

  Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch ...

  Citation × Citation Citation Abstract Copy Title: Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA Author: Christy, John A. Year: 2013 Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch associations are being infilled by a combination of plant succession and invasive species. Repeat photography using aerial and ground-based imagery is recommended as a way to gauge the rate of change in dune communities. Prescribed fire is recommended to monitor rejuvenation effects on two shore pine woodland associations that are most at risk of infilling. Vegetation mapping based on remote sensing will enable more accurate assessment of vegetation features, and facilitate modeling of management scenarios and effects of seal level rise, earthquakes, and tsunamis. Title: Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA Author: Christy, John A. Year: 2013 Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch associations are being infilled by a combination of plant succession and invasive species. Repeat photography using aerial and ground-based imagery is recommended as a way to gauge the rate of change in dune communities. Prescribed fire is recommended to monitor rejuvenation effects on two shore pine woodland associations that are most at risk of infilling. Vegetation mapping based on remote sensing will enable more accurate assessment of vegetation features, and facilitate modeling of management scenarios and effects of seal level rise, earthquakes, and tsunamis. Close

• 23. [Article] Broad-Scale Non-indigenous Species Monitoring along the West Coast in National Marine Sanctuaries and National Estuarine Research Reserves

  Nonindigenous species have caused substantial environmental and economic damage to coastal areas. Moreover, the extent and impacts of nonindigenous species are increasing over time. To develop predictive ...

  Citation × Citation Citation Abstract Copy Title: Broad-Scale Non-indigenous Species Monitoring along the West Coast in National Marine Sanctuaries and National Estuarine Research Reserves Author: de Rivera, Catherine E., Ruiz, Greg, Crooks, Jeff, Wasson, Kerstin, Lonhart, Steve, Fofonoff, Paul, Steves, Brian, Rumrill, Steven S., Brancato, Mary Sue, Pegau, Scott, Bulthuis, Doug, Preisler, Rikke Kvist, Schoch, Carl, Bowlby, Ed, DeVogelaere, Andrew, Crawford, Maurice, Gittings, Steve, Hines, Anson, Takata, Lynn, Larson, Kristen, Huber, Tami, Leyman, Anne Marie, Collinetti, Esther, Pascot, Tiffany, Shull, Suzanne, Anderson, Mary, Powell, Sue Year: 2005 Nonindigenous species have caused substantial environmental and economic damage to coastal areas. Moreover, the extent and impacts of nonindigenous species are increasing over time. To develop predictive models and to identify which areas should be targeted for impact mitigation or early detection, we need a basic foundation of knowledge about the spatial and temporal patterns of invasions. This project was developed because we lacked the necessary data to rigorously evaluate the patterns of coastal invasions. This collaborative project, between the Smithsonian Environmental Research Center, the National Estuarine Research Reserve System (NERRS) and the National Marine Sanctuary Program (NMSP), established a rigorous, largescale monitoring and research program for invasive species in nine protected coastal areas along the US West Coast from San Diego, CA, to Kachemak Bay, AK. Our research included two components, broad-scale and site-specific projects. The broad-scale component focused on using standardized protocols to collect data on the composition of fouling communities and nearshore fish and crabs. We collected data from 310 settling plates and 140 traps across nine NERRS Reserves and NMSP Sanctuaries. The four most common taxa on the settling plates were Bryozoa, Tunicata, Cirripedia, and Hydrozoa. We identified these four taxa and also Nudibranchia, a mobile molluscan taxa often associated with fouling organisms, to species and noted which were nonindigenous. We found 132 species in the 5 taxa under study. NIS accounted for over one quarter of the diversity in these taxa, with 31 NIS identified. Over half of tunicate species were non-native. The documented NIS included two new US west coast sitings plus 3 other range extensions. We documented two patterns in NIS, a latitudinal pattern and differences between NIS impacts in marinas versus non-marina sites; research on salinity differences is still underway. Both the number and percent of NIS decreased with increasing latitude. Tijuana River had the most, 21, NIS and Monterey Bay had the highest proportion of NIS (57%). The same pattern of decreasing NIS with increasing latitude was observed when we examined Tunicata only and Bryozoa only. Across latitudes, plates in marinas were more impacted by NIS than were plates in more natural areas. All NIS but one were found at marinas, whereas only half the NIS were found at the non-marina sites. In addition, NIS at marinas accounted for almost 80% of the NIS per site. Therefore, we were able to provide information on the relative risk of invasions for different taxonomic groups and geographic regions. The spatial and habitat patterns can be used for future predictions and will be of even more value once they are confirmed with additional taxonomic groups and hypothesis-driven studies that will continue from this initial study. Our broad-scale trapping study illustrated how recently-introduced NIS quickly can become numerically dominant. Although we only found Carcinus maenas at Elkhorn Slough NERR, this recently introduced nonindigenous crab was very common at this Reserve and was the most abundant crab in our traps at 3 of 7 Elkhorn sites. The site-specific projects were conducted at each Reserve plus Olympic Coast and Monterey Bay Sanctuaries. Several are serving as the first important step in longer term research, such as examining whether a change in shipping policy in Kachemak Bay will increase NIS. Others, such as the South Slough project examining the effect of a salinity cline on the number and proportion of NIS, will be expanded to test hypotheses across several protected areas. Many of these site-specific projects still need further analyses, and analysis is underway. Title: Broad-Scale Non-indigenous Species Monitoring along the West Coast in National Marine Sanctuaries and National Estuarine Research Reserves Author: de Rivera, Catherine E., Ruiz, Greg, Crooks, Jeff, Wasson, Kerstin, Lonhart, Steve, Fofonoff, Paul, Steves, Brian, Rumrill, Steven S., Brancato, Mary Sue, Pegau, Scott, Bulthuis, Doug, Preisler, Rikke Kvist, Schoch, Carl, Bowlby, Ed, DeVogelaere, Andrew, Crawford, Maurice, Gittings, Steve, Hines, Anson, Takata, Lynn, Larson, Kristen, Huber, Tami, Leyman, Anne Marie, Collinetti, Esther, Pascot, Tiffany, Shull, Suzanne, Anderson, Mary, Powell, Sue Year: 2005 Nonindigenous species have caused substantial environmental and economic damage to coastal areas. Moreover, the extent and impacts of nonindigenous species are increasing over time. To develop predictive models and to identify which areas should be targeted for impact mitigation or early detection, we need a basic foundation of knowledge about the spatial and temporal patterns of invasions. This project was developed because we lacked the necessary data to rigorously evaluate the patterns of coastal invasions. This collaborative project, between the Smithsonian Environmental Research Center, the National Estuarine Research Reserve System (NERRS) and the National Marine Sanctuary Program (NMSP), established a rigorous, largescale monitoring and research program for invasive species in nine protected coastal areas along the US West Coast from San Diego, CA, to Kachemak Bay, AK. Our research included two components, broad-scale and site-specific projects. The broad-scale component focused on using standardized protocols to collect data on the composition of fouling communities and nearshore fish and crabs. We collected data from 310 settling plates and 140 traps across nine NERRS Reserves and NMSP Sanctuaries. The four most common taxa on the settling plates were Bryozoa, Tunicata, Cirripedia, and Hydrozoa. We identified these four taxa and also Nudibranchia, a mobile molluscan taxa often associated with fouling organisms, to species and noted which were nonindigenous. We found 132 species in the 5 taxa under study. NIS accounted for over one quarter of the diversity in these taxa, with 31 NIS identified. Over half of tunicate species were non-native. The documented NIS included two new US west coast sitings plus 3 other range extensions. We documented two patterns in NIS, a latitudinal pattern and differences between NIS impacts in marinas versus non-marina sites; research on salinity differences is still underway. Both the number and percent of NIS decreased with increasing latitude. Tijuana River had the most, 21, NIS and Monterey Bay had the highest proportion of NIS (57%). The same pattern of decreasing NIS with increasing latitude was observed when we examined Tunicata only and Bryozoa only. Across latitudes, plates in marinas were more impacted by NIS than were plates in more natural areas. All NIS but one were found at marinas, whereas only half the NIS were found at the non-marina sites. In addition, NIS at marinas accounted for almost 80% of the NIS per site. Therefore, we were able to provide information on the relative risk of invasions for different taxonomic groups and geographic regions. The spatial and habitat patterns can be used for future predictions and will be of even more value once they are confirmed with additional taxonomic groups and hypothesis-driven studies that will continue from this initial study. Our broad-scale trapping study illustrated how recently-introduced NIS quickly can become numerically dominant. Although we only found Carcinus maenas at Elkhorn Slough NERR, this recently introduced nonindigenous crab was very common at this Reserve and was the most abundant crab in our traps at 3 of 7 Elkhorn sites. The site-specific projects were conducted at each Reserve plus Olympic Coast and Monterey Bay Sanctuaries. Several are serving as the first important step in longer term research, such as examining whether a change in shipping policy in Kachemak Bay will increase NIS. Others, such as the South Slough project examining the effect of a salinity cline on the number and proportion of NIS, will be expanded to test hypotheses across several protected areas. Many of these site-specific projects still need further analyses, and analysis is underway. Close

• 24. [Article] <i>Wolbachia-</i>Host Interactions and the Implications to Insect Conservation and Management

  Parasitic reproductive endosymbionts are emerging as formidable threats to insect biodiversity. Wolbachia are prevalent maternally inherited intra-cellular bacteria found in >50% of arthropod species. ...

  Citation × Citation Citation Abstract Copy Title: <i>Wolbachia-</i>Host Interactions and the Implications to Insect Conservation and Management Author: Truitt, Amy Michelle Year: 2017 Parasitic reproductive endosymbionts are emerging as formidable threats to insect biodiversity. Wolbachia are prevalent maternally inherited intra-cellular bacteria found in >50% of arthropod species. These symbiotic bacteria interact with their hosts in diverse ways, most often they alter host reproduction causing four conditions that all selectively favor infected females: feminization, male killing, parthenogenesis, and cytoplasmic incompatibility (CI). Furthermore, depending on strain-type and host genetic background, Wolbachia are known to affect insect behavior, expand or shift host thermal tolerance ranges, and confer anti-viral protection to their hosts. Because Wolbachia both reside in and are transmitted with host cell cytoplasm, mitochondria and other cytoplasmically inherited genetic elements become linked with the bacteria. Thus, by enhancing their own transmission, Wolbachia-induced phenotypes can lead to mitochondrial selective sweeps, which may have profound impacts on vulnerable and small insect populations. Elucidating the extent to which endosymbionts influence biological and ecological functions is pivotal to making management decisions regarding imperiled insect species. My dissertation investigates biological and ecological impacts of host-endosymbiont interactions by examining Wolbachia infections in three different host systems. First, I used the federally threatened butterfly species Speyeria zerene hippolyta to determine whether the general reproductive success of local populations was affected by the introduction of CI-inducing Wolbachia-infected butterflies through implemented species recovery programs. Next, by characterizing the Wolbachia infections of parasitoids associated with the Eurema butterfly clade, I analyzed whether host-parasitoid interactions provide a path for interspecies horizontal transmission. Finally, I conducted a laboratory experiment using an isogenic Drosophila melanogaster line to determine whether Wolbachia influence host temperature preference. Together, my research examines how the individual level effects of host-endosymbiont interactions can expand into populations, have broader impacts on insect communities, and potentially impede the conservation and management of insects in nature. In chapter one, I screened S. z. hippolyta samples from three extant populations for Wolbachia infection. To examine the impacts of Wolbachia on small populations, I analyzed and compared infected and uninfected S. z. hippolyta reproductive data and showed that, in a population composed of infected and uninfected S. z. hippolyta, uninfected butterflies had reduced reproductive success (GLMM z = -8.067, P < 0.0001). I then developed a single-population demographic theoretical model using these same reproductive data to simulate and analyze different potential dynamics of small populations resulting from population supplementation with uninfected, CI-Wolbachia infected, or combined uninfected and infected butterflies. Analysis of model simulations revealed that supplementation with CI-inducing butterflies significantly suppressed host-population size (ANOVA F5,593 = 3349, PWolbachia-infected individuals (Tukey's post-hoc test P < 0.0001). In addition, supplementation by multiple releases using a combination of 50 infected and 300 uninfected butterflies has a less severe suppression effect, reducing the population by 75.8%, but the reduction occurs 42.6% faster than with the single release of 50 Wolbachia-infected butterflies (Tukey's post-doc test P < 0.0001). Parasitoid-host interactions have emerged as probable ecological relationships to facilitate horizontal transmission of Wolbachia. In chapter two, I addressed horizontal transmission using Eurema butterflies and their associated parasitoids. From four locations in Northern Queensland, Australia, I collected a total of 404 Eurema hecabe butterfly larvae. Twenty-three parasitoids emerged from the larvae of which 21 were Diptera and two were Hymenoptera. I amplified COI loci fragments from each parasitoid for BLAST query searches and found that 20 individual Diptera parasitoids matched to the genus Exorista and one to the genus Senometopia. One of the Hymenoptera parasitoids matched to the genus Microoplitis and the other to the genus Cotesia. To characterize Wolbachia infections, I used Wolbachia Multi Locus Sequencing Technique (MLST) and discovered that all 20 Exorista parasitoids were infected with an identical Wolbachia strain (ST-41), which is the same strain infecting their Eurema hecabe butterfly hosts. Although, further experiments are necessary to definitively determine that ST-41 Wolbachia are incorporated into germline cells of the parasitoids, this is the first study to provide ecological evidence for inter-ordinal Wolbachia transmission between Lepidoptera and Diptera. Furthermore, this discovery exposes the risk of population augmentation programs that move insects, potentially facilitating the spread of Wolbachia between species within a community through the accidental introduction of new Wolbachia-infected parasitoids. Finally, both Wolbachia and their insect hosts are temperature sensitive organisms. Wolbachia’s replication behavior in their hosts is positively-temperature dependent, while environmental variation can have profound effects on insect’s immune function, fitness, and fecundity. In chapter three, I conducted a laboratory experiment using a thermal gradient choice assay and an isogenic Drosophila melanogaster line with four different Wolbachia infection statuses – uninfected, wMel, wMelCS, and wMelPop - to assess whether a relationship existed between Wolbachia infection and host temperature preference. Results from my laboratory experiment revealed that Wolbachia-infected flies preferred cooler temperatures compared to uninfected flies. Moreover, D. melanogaster temperature preferences varied depending on the Wolbachia strain variant with which they were infected; flies infected with the wMel strain had temperature preferences 2°C cooler compared to uninfected flies; flies infected with either wMelCS or wMelPop strains had preferred temperatures 8°C cooler compared to uninfected flies. Wolbachia-associated temperature preference variation within a species can lead to conspecifics occupying different microclimates, genetically adapting to different sets of specific environmental conditions, and may eventually result in ecological and reproductive isolation. While, reproduction isolation is recognized as one of the first stages in speciation, in small populations of endangered and threatened species, the inability to reproduce between conspecifics can drive species to extirpation or extinction. Collectively, the three chapters of my dissertation set precedent for future integration of host-endosymbiont research prior to implementing population supplementation or translocation programs for the conservation of imperiled insects. Title: <i>Wolbachia-</i>Host Interactions and the Implications to Insect Conservation and Management Author: Truitt, Amy Michelle Year: 2017 Parasitic reproductive endosymbionts are emerging as formidable threats to insect biodiversity. Wolbachia are prevalent maternally inherited intra-cellular bacteria found in >50% of arthropod species. These symbiotic bacteria interact with their hosts in diverse ways, most often they alter host reproduction causing four conditions that all selectively favor infected females: feminization, male killing, parthenogenesis, and cytoplasmic incompatibility (CI). Furthermore, depending on strain-type and host genetic background, Wolbachia are known to affect insect behavior, expand or shift host thermal tolerance ranges, and confer anti-viral protection to their hosts. Because Wolbachia both reside in and are transmitted with host cell cytoplasm, mitochondria and other cytoplasmically inherited genetic elements become linked with the bacteria. Thus, by enhancing their own transmission, Wolbachia-induced phenotypes can lead to mitochondrial selective sweeps, which may have profound impacts on vulnerable and small insect populations. Elucidating the extent to which endosymbionts influence biological and ecological functions is pivotal to making management decisions regarding imperiled insect species. My dissertation investigates biological and ecological impacts of host-endosymbiont interactions by examining Wolbachia infections in three different host systems. First, I used the federally threatened butterfly species Speyeria zerene hippolyta to determine whether the general reproductive success of local populations was affected by the introduction of CI-inducing Wolbachia-infected butterflies through implemented species recovery programs. Next, by characterizing the Wolbachia infections of parasitoids associated with the Eurema butterfly clade, I analyzed whether host-parasitoid interactions provide a path for interspecies horizontal transmission. Finally, I conducted a laboratory experiment using an isogenic Drosophila melanogaster line to determine whether Wolbachia influence host temperature preference. Together, my research examines how the individual level effects of host-endosymbiont interactions can expand into populations, have broader impacts on insect communities, and potentially impede the conservation and management of insects in nature. In chapter one, I screened S. z. hippolyta samples from three extant populations for Wolbachia infection. To examine the impacts of Wolbachia on small populations, I analyzed and compared infected and uninfected S. z. hippolyta reproductive data and showed that, in a population composed of infected and uninfected S. z. hippolyta, uninfected butterflies had reduced reproductive success (GLMM z = -8.067, P < 0.0001). I then developed a single-population demographic theoretical model using these same reproductive data to simulate and analyze different potential dynamics of small populations resulting from population supplementation with uninfected, CI-Wolbachia infected, or combined uninfected and infected butterflies. Analysis of model simulations revealed that supplementation with CI-inducing butterflies significantly suppressed host-population size (ANOVA F5,593 = 3349, PWolbachia-infected individuals (Tukey's post-hoc test P < 0.0001). In addition, supplementation by multiple releases using a combination of 50 infected and 300 uninfected butterflies has a less severe suppression effect, reducing the population by 75.8%, but the reduction occurs 42.6% faster than with the single release of 50 Wolbachia-infected butterflies (Tukey's post-doc test P < 0.0001). Parasitoid-host interactions have emerged as probable ecological relationships to facilitate horizontal transmission of Wolbachia. In chapter two, I addressed horizontal transmission using Eurema butterflies and their associated parasitoids. From four locations in Northern Queensland, Australia, I collected a total of 404 Eurema hecabe butterfly larvae. Twenty-three parasitoids emerged from the larvae of which 21 were Diptera and two were Hymenoptera. I amplified COI loci fragments from each parasitoid for BLAST query searches and found that 20 individual Diptera parasitoids matched to the genus Exorista and one to the genus Senometopia. One of the Hymenoptera parasitoids matched to the genus Microoplitis and the other to the genus Cotesia. To characterize Wolbachia infections, I used Wolbachia Multi Locus Sequencing Technique (MLST) and discovered that all 20 Exorista parasitoids were infected with an identical Wolbachia strain (ST-41), which is the same strain infecting their Eurema hecabe butterfly hosts. Although, further experiments are necessary to definitively determine that ST-41 Wolbachia are incorporated into germline cells of the parasitoids, this is the first study to provide ecological evidence for inter-ordinal Wolbachia transmission between Lepidoptera and Diptera. Furthermore, this discovery exposes the risk of population augmentation programs that move insects, potentially facilitating the spread of Wolbachia between species within a community through the accidental introduction of new Wolbachia-infected parasitoids. Finally, both Wolbachia and their insect hosts are temperature sensitive organisms. Wolbachia’s replication behavior in their hosts is positively-temperature dependent, while environmental variation can have profound effects on insect’s immune function, fitness, and fecundity. In chapter three, I conducted a laboratory experiment using a thermal gradient choice assay and an isogenic Drosophila melanogaster line with four different Wolbachia infection statuses – uninfected, wMel, wMelCS, and wMelPop - to assess whether a relationship existed between Wolbachia infection and host temperature preference. Results from my laboratory experiment revealed that Wolbachia-infected flies preferred cooler temperatures compared to uninfected flies. Moreover, D. melanogaster temperature preferences varied depending on the Wolbachia strain variant with which they were infected; flies infected with the wMel strain had temperature preferences 2°C cooler compared to uninfected flies; flies infected with either wMelCS or wMelPop strains had preferred temperatures 8°C cooler compared to uninfected flies. Wolbachia-associated temperature preference variation within a species can lead to conspecifics occupying different microclimates, genetically adapting to different sets of specific environmental conditions, and may eventually result in ecological and reproductive isolation. While, reproduction isolation is recognized as one of the first stages in speciation, in small populations of endangered and threatened species, the inability to reproduce between conspecifics can drive species to extirpation or extinction. Collectively, the three chapters of my dissertation set precedent for future integration of host-endosymbiont research prior to implementing population supplementation or translocation programs for the conservation of imperiled insects. Close

• 25. [Article] Interactions Among Fuel Management, Species Composition, Bark Beetles, and Climate Change and the Potential Effects on Forests of the Lake Tahoe Basin

  Climate-driven increases in wildfires, drought conditions, and insect outbreaks are critical threats to forest carbon stores. In particular, bark beetles are important disturbance agents although their ...

  Citation × Citation Citation Abstract Copy Title: Interactions Among Fuel Management, Species Composition, Bark Beetles, and Climate Change and the Potential Effects on Forests of the Lake Tahoe Basin Author: Scheller, Robert M., Kretchun, Alec M., Loudermilk, E. Louise, Hurteau, Matthew D., Weisberg, Peter J., Skinner, Carl Year: 2017 Climate-driven increases in wildfires, drought conditions, and insect outbreaks are critical threats to forest carbon stores. In particular, bark beetles are important disturbance agents although their long-term interactions with future climate change are poorly understood. Droughts and the associated moisture deficit contribute to the onset of bark beetle outbreaks although outbreak extent and severity is dependent upon the density of host trees, wildfire, and forest management. Our objective was to estimate the effects of climate change and bark beetle outbreaks on ecosystem carbon dynamics over the next century in a western US forest. Specifically, we hypothesized that (a) bark beetle outbreaks under climate change would reduce net ecosystem carbon balance (NECB) and increase uncertainty and (b) these effects could be ameliorated by fuels management. We also examined the specific tree species dynamics—competition and release—that determined NECB response to bark beetle outbreaks. Our study area was the Lake Tahoe Basin (LTB), CA and NV, USA, an area of diverse forest types encompassing steep elevation and climatic gradients and representative of mixed-conifer forests throughout the western United States. We simulated climate change, bark beetles, wildfire, and fuels management using a landscape-scale stochastic model of disturbance and succession. We simulated the period 2010–2100 using downscaled climate projections. Recurring droughts generated conditions conducive to large-scale outbreaks; the resulting large and sustained outbreaks significantly increased the probability of LTB forests becoming C sources over decadal time scales, with slower-than-anticipated landscape-scale recovery. Tree species composition was substantially altered with a reduction in functional redundancy and productivity. Results indicate heightened uncertainty due to the synergistic influences of climate change and interacting disturbances. Our results further indicate that current fuel management practices will not be effective at reducing landscape-scale outbreak mortality. Our results provide critical insights into the interaction of drivers (bark beetles, wildfire, fuel management) that increase the risk of C loss and shifting community composition if bark beetle outbreaks become more frequent. Title: Interactions Among Fuel Management, Species Composition, Bark Beetles, and Climate Change and the Potential Effects on Forests of the Lake Tahoe Basin Author: Scheller, Robert M., Kretchun, Alec M., Loudermilk, E. Louise, Hurteau, Matthew D., Weisberg, Peter J., Skinner, Carl Year: 2017 Climate-driven increases in wildfires, drought conditions, and insect outbreaks are critical threats to forest carbon stores. In particular, bark beetles are important disturbance agents although their long-term interactions with future climate change are poorly understood. Droughts and the associated moisture deficit contribute to the onset of bark beetle outbreaks although outbreak extent and severity is dependent upon the density of host trees, wildfire, and forest management. Our objective was to estimate the effects of climate change and bark beetle outbreaks on ecosystem carbon dynamics over the next century in a western US forest. Specifically, we hypothesized that (a) bark beetle outbreaks under climate change would reduce net ecosystem carbon balance (NECB) and increase uncertainty and (b) these effects could be ameliorated by fuels management. We also examined the specific tree species dynamics—competition and release—that determined NECB response to bark beetle outbreaks. Our study area was the Lake Tahoe Basin (LTB), CA and NV, USA, an area of diverse forest types encompassing steep elevation and climatic gradients and representative of mixed-conifer forests throughout the western United States. We simulated climate change, bark beetles, wildfire, and fuels management using a landscape-scale stochastic model of disturbance and succession. We simulated the period 2010–2100 using downscaled climate projections. Recurring droughts generated conditions conducive to large-scale outbreaks; the resulting large and sustained outbreaks significantly increased the probability of LTB forests becoming C sources over decadal time scales, with slower-than-anticipated landscape-scale recovery. Tree species composition was substantially altered with a reduction in functional redundancy and productivity. Results indicate heightened uncertainty due to the synergistic influences of climate change and interacting disturbances. Our results further indicate that current fuel management practices will not be effective at reducing landscape-scale outbreak mortality. Our results provide critical insights into the interaction of drivers (bark beetles, wildfire, fuel management) that increase the risk of C loss and shifting community composition if bark beetle outbreaks become more frequent. Close

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

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

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

• 27. [Article] Total Mercury in Stranded Marine Mammals from the Oregon and Southern Washington Coasts

  Muscle samples from 105 marine mammals stranded along the Oregon-Washington coasts (2002-2009) were tested for levels of total mercury by Cold Vapor Atomic Fluorescence Spectrometry. The total mercury ...

  Citation × Citation Citation Abstract Copy Title: Total Mercury in Stranded Marine Mammals from the Oregon and Southern Washington Coasts Author: Wintle, Nathan J. Year: 2011 Muscle samples from 105 marine mammals stranded along the Oregon-Washington coasts (2002-2009) were tested for levels of total mercury by Cold Vapor Atomic Fluorescence Spectrometry. The total mercury present is predominantly in the form of highly toxic methylmercury. After normalizing muscle tissue to 75% water weight, due to variance in water content, Steller sea lions (Eumetopias jubatus) and northern elephant seals (Mirounga angustirostris) exhibited the highest mean concentrations of total mercury followed by harbor seals (Phoca vitulina), harbor porpoises (Phocoena phocoena), and California sea lions (Zalophus californianus); 0.34 ± 0.278, 0.34 ± 0.485, 0.21 ± 0.216, 0.17 ± 0.169 and 0.15 ± 0.126 mg/kg normalized weight, respectively. Mean normalized values demonstrated limited muscle methylmercury accumulation in these species in the Pacific Northwest. Normalizing muscle mercury concentrations eliminated variability from desiccation, and allowed for a clearer indication of the amount of mercury the animal accumulated before stranding. However, actual wet weight concentrations in some of the stranded carcasses were high enough to pose a risk to scavengers. Title: Total Mercury in Stranded Marine Mammals from the Oregon and Southern Washington Coasts Author: Wintle, Nathan J. Year: 2011 Muscle samples from 105 marine mammals stranded along the Oregon-Washington coasts (2002-2009) were tested for levels of total mercury by Cold Vapor Atomic Fluorescence Spectrometry. The total mercury present is predominantly in the form of highly toxic methylmercury. After normalizing muscle tissue to 75% water weight, due to variance in water content, Steller sea lions (Eumetopias jubatus) and northern elephant seals (Mirounga angustirostris) exhibited the highest mean concentrations of total mercury followed by harbor seals (Phoca vitulina), harbor porpoises (Phocoena phocoena), and California sea lions (Zalophus californianus); 0.34 ± 0.278, 0.34 ± 0.485, 0.21 ± 0.216, 0.17 ± 0.169 and 0.15 ± 0.126 mg/kg normalized weight, respectively. Mean normalized values demonstrated limited muscle methylmercury accumulation in these species in the Pacific Northwest. Normalizing muscle mercury concentrations eliminated variability from desiccation, and allowed for a clearer indication of the amount of mercury the animal accumulated before stranding. However, actual wet weight concentrations in some of the stranded carcasses were high enough to pose a risk to scavengers. Close

• 28. [Article] Investigation of Ambient Reactive Nitrogen Emissions Sources and Deposition in the Columbia River Gorge National Scenic Area

  Anthropogenic reactive nitrogen is emitted into the atmosphere from fossil fuel combustion (nitrogen oxides) and agricultural activities (nitrogen oxides and ammonia). Nitrogen oxide emissions have long ...

  Citation × Citation Citation Abstract Copy Title: Investigation of Ambient Reactive Nitrogen Emissions Sources and Deposition in the Columbia River Gorge National Scenic Area Author: Mainord, Jacinda L. Year: 2017 Anthropogenic reactive nitrogen is emitted into the atmosphere from fossil fuel combustion (nitrogen oxides) and agricultural activities (nitrogen oxides and ammonia). Nitrogen oxide emissions have long been controlled for their role in ambient air pollution and human health effects. However, reactive nitrogen deposition is less understood even though it can play a significant role in altering biodiversity, impairing ecosystem and biogeochemical function and degrading cultural artifacts. Although nitrogen deposition is a natural part of biogeochemical cycling, many ecosystems across the United States are at risk of exceeding the critical nitrogen deposition load. While nitrogen oxides are routinely measured in urban areas, far less is known in non-urban landscapes where ecosystems may be especially sensitive. Regional chemical transport models have been used to predict the impacts of ambient reactive nitrogen deposition in non-urban areas, but models have difficulty simulating reactive nitrogen due to poorly quantified emissions, especially from the agricultural sector. My research explores the speciated deposition of reactive nitrogen through monitoring and modeling in the unique field setting of the 150 mile Columbia River Gorge (CRG) located along the border of Oregon and Washington. This site is ideally suited for this investigation due to the large sources of reactive nitrogen at either end of the CRG and unique seasonally driven channel wind flow. Seasonally driven wind allowed us to look at the reactive nitrogen emissions flowing through the CRG to assess ambient the reactive nitrogen partitioning and deposition gradient. Using data collected by the United States Forest Service to control ambient haze in the CRG and our co-located nitrogen oxides (NOx) gas analyzer, we first characterized the influence of seasonal, bimodal wind distributions on the spatial distribution of reactive nitrogen. We found that during winter months with predominantly easterly winds, particulate nitrate and ammonium and gas-phase nitrogen dioxide levels create a gradient from the eastern end to the western end. Particulate nitrate and sulfate mass concentrations influence the CRG gradient during summer months with predominantly western winds. We also found that the magnitude of the impact from east is greater than the magnitude of impact from the west. When we compared our observations to regional chemistry transport models, we found that models are significantly under-predicting levels of reactive nitrogen in the CRG. This bias is not isolated to a single station within the Gorge, but throughout the whole Columbia Basin. Our results indicate that there are under-represented emissions in the region leading to this bias. Partly due to the bias in reactive N gas-phase species in the CRG, regional models have been underestimating the impact of gas-phase reactive N on dry N deposition. We conducted field studies at two sites within the CRG monitoring reactive nitrogen species (nitric oxide, nitrogen dioxide, ammonia, nitric acid, particulate nitrate, particulate ammonium, and particulate sulfate) as well as ozone and meteorological parameters. These measurements allowed us to conduct the first comprehensive analysis of reactive nitrogen partitioning and deposition in the CRG. Through our measurements, we found reactive nitrogen was higher in the spring than the summer. We found concentrations ranging from 0-15 ppbv ammonia, 0-7 ppbv nitric acid, 0-2 μg/m3 ammonium nitrate and 0-1 μg/m3 ammonium sulfate at the sites. Through the measurements of all these species, we evaluated the limiting gas-phase precursor to inorganic nitrogen particle formation. In the springtime, ammonia limits the formation of particulate reactive nitrogen; while in the summer, nitric acid and oxidized sulfur limit the formation of inorganic nitrogen particles. This suggests that there may be more sources of ammonia in the spring with fertilizer application or perhaps reactive nitrogen reservoirs are renoxified through thermal dissociation during warmer summer months. Our estimated deposition from gas and particle phase reactive nitrogen ranged from 0 – 0.14 kg N/ha per day. We also found that gas-phase reactive nitrogen plays the largest role in dry N deposition in the CRG with particle-phase contributing less than 15% of total dry N deposition. These results are important for land managers to understand the total impact of reactive nitrogen to non-urban areas. This research can inform mitigation strategies for haze formation, identify the major species and sources involved in dry N deposition and assess the potential impacts to ecosystems and cultural artifacts. Title: Investigation of Ambient Reactive Nitrogen Emissions Sources and Deposition in the Columbia River Gorge National Scenic Area Author: Mainord, Jacinda L. Year: 2017 Anthropogenic reactive nitrogen is emitted into the atmosphere from fossil fuel combustion (nitrogen oxides) and agricultural activities (nitrogen oxides and ammonia). Nitrogen oxide emissions have long been controlled for their role in ambient air pollution and human health effects. However, reactive nitrogen deposition is less understood even though it can play a significant role in altering biodiversity, impairing ecosystem and biogeochemical function and degrading cultural artifacts. Although nitrogen deposition is a natural part of biogeochemical cycling, many ecosystems across the United States are at risk of exceeding the critical nitrogen deposition load. While nitrogen oxides are routinely measured in urban areas, far less is known in non-urban landscapes where ecosystems may be especially sensitive. Regional chemical transport models have been used to predict the impacts of ambient reactive nitrogen deposition in non-urban areas, but models have difficulty simulating reactive nitrogen due to poorly quantified emissions, especially from the agricultural sector. My research explores the speciated deposition of reactive nitrogen through monitoring and modeling in the unique field setting of the 150 mile Columbia River Gorge (CRG) located along the border of Oregon and Washington. This site is ideally suited for this investigation due to the large sources of reactive nitrogen at either end of the CRG and unique seasonally driven channel wind flow. Seasonally driven wind allowed us to look at the reactive nitrogen emissions flowing through the CRG to assess ambient the reactive nitrogen partitioning and deposition gradient. Using data collected by the United States Forest Service to control ambient haze in the CRG and our co-located nitrogen oxides (NOx) gas analyzer, we first characterized the influence of seasonal, bimodal wind distributions on the spatial distribution of reactive nitrogen. We found that during winter months with predominantly easterly winds, particulate nitrate and ammonium and gas-phase nitrogen dioxide levels create a gradient from the eastern end to the western end. Particulate nitrate and sulfate mass concentrations influence the CRG gradient during summer months with predominantly western winds. We also found that the magnitude of the impact from east is greater than the magnitude of impact from the west. When we compared our observations to regional chemistry transport models, we found that models are significantly under-predicting levels of reactive nitrogen in the CRG. This bias is not isolated to a single station within the Gorge, but throughout the whole Columbia Basin. Our results indicate that there are under-represented emissions in the region leading to this bias. Partly due to the bias in reactive N gas-phase species in the CRG, regional models have been underestimating the impact of gas-phase reactive N on dry N deposition. We conducted field studies at two sites within the CRG monitoring reactive nitrogen species (nitric oxide, nitrogen dioxide, ammonia, nitric acid, particulate nitrate, particulate ammonium, and particulate sulfate) as well as ozone and meteorological parameters. These measurements allowed us to conduct the first comprehensive analysis of reactive nitrogen partitioning and deposition in the CRG. Through our measurements, we found reactive nitrogen was higher in the spring than the summer. We found concentrations ranging from 0-15 ppbv ammonia, 0-7 ppbv nitric acid, 0-2 μg/m3 ammonium nitrate and 0-1 μg/m3 ammonium sulfate at the sites. Through the measurements of all these species, we evaluated the limiting gas-phase precursor to inorganic nitrogen particle formation. In the springtime, ammonia limits the formation of particulate reactive nitrogen; while in the summer, nitric acid and oxidized sulfur limit the formation of inorganic nitrogen particles. This suggests that there may be more sources of ammonia in the spring with fertilizer application or perhaps reactive nitrogen reservoirs are renoxified through thermal dissociation during warmer summer months. Our estimated deposition from gas and particle phase reactive nitrogen ranged from 0 – 0.14 kg N/ha per day. We also found that gas-phase reactive nitrogen plays the largest role in dry N deposition in the CRG with particle-phase contributing less than 15% of total dry N deposition. These results are important for land managers to understand the total impact of reactive nitrogen to non-urban areas. This research can inform mitigation strategies for haze formation, identify the major species and sources involved in dry N deposition and assess the potential impacts to ecosystems and cultural artifacts. Close

• 29. [Article] OSMB Final Report: Task 5. Zebra and Quagga Mussel Early-Detection Monitoring in High Risk Oregon Waters

  Neither zebra nor quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively) were detected by Portland State University (PSU) during their early detection sampling in Oregon water ...

  Citation × Citation Citation Abstract Copy Title: OSMB Final Report: Task 5. Zebra and Quagga Mussel Early-Detection Monitoring in High Risk Oregon Waters Author: Wells, Steve W., Sytsma, Mark Year: 2014 Neither zebra nor quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively) were detected by Portland State University (PSU) during their early detection sampling in Oregon water bodies during 2013. PSU conducted sampling for planktonic larvae, juvenile, and adult mussels at nine Oregon water bodies during the July to August period coinciding with water temperatures favorable for mussel spawning. A total of 113 plankton samples were collected and over 1.6 million liters of lake water were filtered through 63-μm mesh nets during plankton sample collection. The greatest sampling effort occurred in East Lake, Prineville Reservoir, and Paulina Lake; these water bodies were identified as high risk for both mussel establishment and introduction according to Wells et al. (2009). The sampling effort, however, was fairly uniform amongst the targeted water bodies, and sampling also occurred in Upper Klamath Lake, Howard Prairie Lake, Hyatt Reservoir, Emigrant Lake, Ochoco Reservoir, and Lake Billy Chinook. Non-native invertebrates and macrophytes were opportunistically collected during Dreissena spp. sampling in 2013. Corbicula fluminea (Asian clam) straight-hinge juveniles were collected in plankton samples from East Lake and Howard Prairie Lake. Potamopyrgus antipodarum (New Zealand mud snails) were collected in Lake Billy Chinook. Radix auricularia (big-ear radix) snails were collected in Hyatt Reservoir, Lake Billy Chinook and Paulina Lake. Orconectes neglectus (ringed crayfish) were collected in Hyatt Reservoir. Potamogeton crispus (curly leaf pondweed) were collected in Howard Prairie Lake, Hyatt Reservoir, Lake Billy Chinook, and Upper Klamath Lake. Most of these collections were not the first detections for these species in these locations; however, to the authors’ knowledge, the following represent first detections: R. auricularia in Hyatt Reservoir and Paulina Lake, O. neglectus in Hyatt Reservoir and C. fluminea in Howard Prairie Lake. Title: OSMB Final Report: Task 5. Zebra and Quagga Mussel Early-Detection Monitoring in High Risk Oregon Waters Author: Wells, Steve W., Sytsma, Mark Year: 2014 Neither zebra nor quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively) were detected by Portland State University (PSU) during their early detection sampling in Oregon water bodies during 2013. PSU conducted sampling for planktonic larvae, juvenile, and adult mussels at nine Oregon water bodies during the July to August period coinciding with water temperatures favorable for mussel spawning. A total of 113 plankton samples were collected and over 1.6 million liters of lake water were filtered through 63-μm mesh nets during plankton sample collection. The greatest sampling effort occurred in East Lake, Prineville Reservoir, and Paulina Lake; these water bodies were identified as high risk for both mussel establishment and introduction according to Wells et al. (2009). The sampling effort, however, was fairly uniform amongst the targeted water bodies, and sampling also occurred in Upper Klamath Lake, Howard Prairie Lake, Hyatt Reservoir, Emigrant Lake, Ochoco Reservoir, and Lake Billy Chinook. Non-native invertebrates and macrophytes were opportunistically collected during Dreissena spp. sampling in 2013. Corbicula fluminea (Asian clam) straight-hinge juveniles were collected in plankton samples from East Lake and Howard Prairie Lake. Potamopyrgus antipodarum (New Zealand mud snails) were collected in Lake Billy Chinook. Radix auricularia (big-ear radix) snails were collected in Hyatt Reservoir, Lake Billy Chinook and Paulina Lake. Orconectes neglectus (ringed crayfish) were collected in Hyatt Reservoir. Potamogeton crispus (curly leaf pondweed) were collected in Howard Prairie Lake, Hyatt Reservoir, Lake Billy Chinook, and Upper Klamath Lake. Most of these collections were not the first detections for these species in these locations; however, to the authors’ knowledge, the following represent first detections: R. auricularia in Hyatt Reservoir and Paulina Lake, O. neglectus in Hyatt Reservoir and C. fluminea in Howard Prairie Lake. Close

• 30. [Article] Connecting Habitat Across Roads: Field Testing Mitigation Strategies for Reducing Road Mortality of an Imperiled Butterfly

  Roads impact wildlife in a variety of ways including fragmentation of populations, reduced access to habitat, and direct mortality from vehicle strikes. Such road effects likely impact the Oregon silverspot ...

  Citation × Citation Citation Abstract Copy Title: Connecting Habitat Across Roads: Field Testing Mitigation Strategies for Reducing Road Mortality of an Imperiled Butterfly Author: Littlejohn, Rebecca Jalene Year: 2012 Roads impact wildlife in a variety of ways including fragmentation of populations, reduced access to habitat, and direct mortality from vehicle strikes. Such road effects likely impact the Oregon silverspot butterfly (Speyeria zerene hippolyta) at one of its few remaining sites. The Rock Creek-Big Creek population of this threatened fritillary butterfly species is bisected by highway 101 on the central Oregon coast. Habitat resources for S. z. hippolyta are found on both the east and west sides of the highway at this site, and vehicle-strikes have been found to cause mortality of some individuals crossing the highway. The 2001 revised Recovery Plan calls out road mortality as a primary threat to S. z. hippolyta and land managers are considering mitigation strategies to reduce this threat on the population. A previous study at Rock Creek- Big Creek prioritized mitigation strategies including mowing of the road sides to decrease flowering plants along the verge and installation of vegetative hedgerows along the highway where the butterflies are crossing to encourage increased flight height over the road. Mowing has taken place over the last two years, but the hedgerows have neither been installed nor tested for effectiveness. This study investigates the effectiveness of hedgerows to increase the flight height of S. z. hippolyta through experimental tests using 3-meter tall nets as "guiding barriers" to mimic vegetative hedgerows in the flight path of S. z. hippolyta at another site in Oregon, Mt. Hebo. Mt. Hebo was chosen because of the stable population of S. z. hippolyta that is found there, the low risk of mortality for individual butterflies during the course of the study, and consistent use of a corridor by S. z. hippolyta. Treatments were designed to mimic a flight path in which a butterfly encounters a "road" of a width simulating that of highway 101 with 3-meter guiding barriers on either side. Based on previous research observations, it was hypothesized that S. z. hippolytaindividuals would fly over the guiding barriers at an increased "safe" flight height such that they would fly over traffic height. Results of the experimental study indicated that a 3-meter guiding barrier in the flight path of S. z. hippolyta did not significantly increase the flight height of individuals. None of the individuals observed flew at a safe flight height over the road (>3 meters). Further, S. z. hippolyta individuals landed on the road surface more often when there was a guiding barrier in the flight path. These results suggest that while S. z. hippolyta individuals are able to fly over guiding barriers in their path at heights of 3 meters or more, there is no evidence to suggest that these structures will influence flight height over highway 101 such that road mortality is reduced. Additionally, this study investigated the known butterfly crossing points at Rock Creek-Big Creek to test the hypothesis that S. z. hippolyta individuals are crossing at points of lower vegetation adjacent to the road. Using data from previous studies, ten crossing points were mapped at this site. Light detection and ranging data (LiDAR) was used to derive vegetation height along highway 101 and analyzed between known crossing points and random points within the Rock Creek-Big Creek area in addition to resource density of the larval host plant (Viola adunca) within the meadows. Statistical analysis indicated that the butterflies were generally crossing at points along the highway with significantly lower vegetation adjacent to the road. Visual analysis indicated that the butterflies were also generally crossing between areas of densely located V. adunca. Additional spatial data is needed to do further path-analysis of S. z. hippolyta individuals. Title: Connecting Habitat Across Roads: Field Testing Mitigation Strategies for Reducing Road Mortality of an Imperiled Butterfly Author: Littlejohn, Rebecca Jalene Year: 2012 Roads impact wildlife in a variety of ways including fragmentation of populations, reduced access to habitat, and direct mortality from vehicle strikes. Such road effects likely impact the Oregon silverspot butterfly (Speyeria zerene hippolyta) at one of its few remaining sites. The Rock Creek-Big Creek population of this threatened fritillary butterfly species is bisected by highway 101 on the central Oregon coast. Habitat resources for S. z. hippolyta are found on both the east and west sides of the highway at this site, and vehicle-strikes have been found to cause mortality of some individuals crossing the highway. The 2001 revised Recovery Plan calls out road mortality as a primary threat to S. z. hippolyta and land managers are considering mitigation strategies to reduce this threat on the population. A previous study at Rock Creek- Big Creek prioritized mitigation strategies including mowing of the road sides to decrease flowering plants along the verge and installation of vegetative hedgerows along the highway where the butterflies are crossing to encourage increased flight height over the road. Mowing has taken place over the last two years, but the hedgerows have neither been installed nor tested for effectiveness. This study investigates the effectiveness of hedgerows to increase the flight height of S. z. hippolyta through experimental tests using 3-meter tall nets as "guiding barriers" to mimic vegetative hedgerows in the flight path of S. z. hippolyta at another site in Oregon, Mt. Hebo. Mt. Hebo was chosen because of the stable population of S. z. hippolyta that is found there, the low risk of mortality for individual butterflies during the course of the study, and consistent use of a corridor by S. z. hippolyta. Treatments were designed to mimic a flight path in which a butterfly encounters a "road" of a width simulating that of highway 101 with 3-meter guiding barriers on either side. Based on previous research observations, it was hypothesized that S. z. hippolytaindividuals would fly over the guiding barriers at an increased "safe" flight height such that they would fly over traffic height. Results of the experimental study indicated that a 3-meter guiding barrier in the flight path of S. z. hippolyta did not significantly increase the flight height of individuals. None of the individuals observed flew at a safe flight height over the road (>3 meters). Further, S. z. hippolyta individuals landed on the road surface more often when there was a guiding barrier in the flight path. These results suggest that while S. z. hippolyta individuals are able to fly over guiding barriers in their path at heights of 3 meters or more, there is no evidence to suggest that these structures will influence flight height over highway 101 such that road mortality is reduced. Additionally, this study investigated the known butterfly crossing points at Rock Creek-Big Creek to test the hypothesis that S. z. hippolyta individuals are crossing at points of lower vegetation adjacent to the road. Using data from previous studies, ten crossing points were mapped at this site. Light detection and ranging data (LiDAR) was used to derive vegetation height along highway 101 and analyzed between known crossing points and random points within the Rock Creek-Big Creek area in addition to resource density of the larval host plant (Viola adunca) within the meadows. Statistical analysis indicated that the butterflies were generally crossing at points along the highway with significantly lower vegetation adjacent to the road. Visual analysis indicated that the butterflies were also generally crossing between areas of densely located V. adunca. Additional spatial data is needed to do further path-analysis of S. z. hippolyta individuals. Close