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• 481. [Article] A cooperative effort to track Humboldt squid invasions in Oregon

  Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing ...

  Citation × Citation Citation Abstract Copy Title: A cooperative effort to track Humboldt squid invasions in Oregon Author: Chesney, Tanya A. Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing their range expansion from Mexico is poorly understood due to the recent nature of their "invasion" and a lack of monitoring. Humboldt squid are large predators that have the potential to affect ecosystem structure and fisheries because of their high-energy demands and ability to exploit a variety of oceanographic conditions and prey sources. Developing baseline distribution information is a critical first step to assess their potential ecological, social, and economic impacts, and to develop models to predict future range expansion. This study has two main objectives: (1) to document where and when Humboldt squid have been present in Oregon through cooperative fisheries research, and (2) to correlate the sightings with oceanographic conditions using a geographic information system (GIS) and species distribution modeling (SDM). I conducted 54 interviews with local fishermen and aggregated their squid sightings with available fishery-independent survey and fishery-dependent observer data from the National Marine Fisheries Service. I compiled a total of 339 Humboldt squid sightings, reported for the years 2002-2011 from the Oregon coast to 131° west longitude. Correlation analyses were performed for Humboldt squid sightings and sea surface temperature (SST), chlorophyll a content (chla), sea surface height anomalies (SSH), dissolved oxygen at 30 m depth (30 m DO), and sea surface salinity (SSS) using a GIS, nonparametric multiplicative regression (NPMR) habitat modeling, and maximum entropy modeling (Maxent). Results indicate that oceanographic conditions have the potential to influence Humboldt squid occurrence, and in Oregon, sightings vary temporally and spatially. Combining the sightings from fishermen and scientific surveys greatly enhanced the spatial extent of the data. Humboldt squid were most frequently observed between 124.4°W and 125°W in proximity to the shelf-break at the 200 m isobath, with peak sightings (116) recorded in 2009 and the fewest (6) reported in 2003 and 2011. The highest occurrence of Humboldt squid were observed at a SST of 10.5-13.0°C, 0.26-3.0 mg m⁻³ chla content, -4.0-1.0 m SSH anomalies, 32.2-32.8 psu SSS, and at 3-4.5 ml L⁻¹ and 6-7 ml L⁻¹ 30 m depth DO. Maps of estimated likelihood of occurrence generated by NPMR were consistent with overlayed observations from fishermen, which were not used in the model because they were limited to presence-only information. An interdisciplinary approach that incorporates cooperative fisheries research and ecosystem-based management is necessary for monitoring Humboldt squid in Oregon. Traditional methods are insufficient because Humboldt squid are data-poor, highly migratory, and are main predators of many commercially important fisheries in Oregon. Based on my findings, sightings recorded by fishermen covered a much larger area over a longer time frame than the scientific survey and observer data, and excluding their knowledge would have led to a different interpretation of Humboldt squid distribution and environmental tolerances. Although there is uncertainty in the data from potential map bias or misidentification of smaller Humboldt squid, incorporating sightings from fishermen with traditional fisheries research increases the quantity and quality of information. Cooperative monitoring for Humboldt squid could include training in species identification and sea condition reporting in logbooks. Future "invasions" are likely, and more eyes on the water will improve our understanding of the behavior and impacts of Humboldt squid on coastal resources. Title: A cooperative effort to track Humboldt squid invasions in Oregon Author: Chesney, Tanya A. Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing their range expansion from Mexico is poorly understood due to the recent nature of their "invasion" and a lack of monitoring. Humboldt squid are large predators that have the potential to affect ecosystem structure and fisheries because of their high-energy demands and ability to exploit a variety of oceanographic conditions and prey sources. Developing baseline distribution information is a critical first step to assess their potential ecological, social, and economic impacts, and to develop models to predict future range expansion. This study has two main objectives: (1) to document where and when Humboldt squid have been present in Oregon through cooperative fisheries research, and (2) to correlate the sightings with oceanographic conditions using a geographic information system (GIS) and species distribution modeling (SDM). I conducted 54 interviews with local fishermen and aggregated their squid sightings with available fishery-independent survey and fishery-dependent observer data from the National Marine Fisheries Service. I compiled a total of 339 Humboldt squid sightings, reported for the years 2002-2011 from the Oregon coast to 131° west longitude. Correlation analyses were performed for Humboldt squid sightings and sea surface temperature (SST), chlorophyll a content (chla), sea surface height anomalies (SSH), dissolved oxygen at 30 m depth (30 m DO), and sea surface salinity (SSS) using a GIS, nonparametric multiplicative regression (NPMR) habitat modeling, and maximum entropy modeling (Maxent). Results indicate that oceanographic conditions have the potential to influence Humboldt squid occurrence, and in Oregon, sightings vary temporally and spatially. Combining the sightings from fishermen and scientific surveys greatly enhanced the spatial extent of the data. Humboldt squid were most frequently observed between 124.4°W and 125°W in proximity to the shelf-break at the 200 m isobath, with peak sightings (116) recorded in 2009 and the fewest (6) reported in 2003 and 2011. The highest occurrence of Humboldt squid were observed at a SST of 10.5-13.0°C, 0.26-3.0 mg m⁻³ chla content, -4.0-1.0 m SSH anomalies, 32.2-32.8 psu SSS, and at 3-4.5 ml L⁻¹ and 6-7 ml L⁻¹ 30 m depth DO. Maps of estimated likelihood of occurrence generated by NPMR were consistent with overlayed observations from fishermen, which were not used in the model because they were limited to presence-only information. An interdisciplinary approach that incorporates cooperative fisheries research and ecosystem-based management is necessary for monitoring Humboldt squid in Oregon. Traditional methods are insufficient because Humboldt squid are data-poor, highly migratory, and are main predators of many commercially important fisheries in Oregon. Based on my findings, sightings recorded by fishermen covered a much larger area over a longer time frame than the scientific survey and observer data, and excluding their knowledge would have led to a different interpretation of Humboldt squid distribution and environmental tolerances. Although there is uncertainty in the data from potential map bias or misidentification of smaller Humboldt squid, incorporating sightings from fishermen with traditional fisheries research increases the quantity and quality of information. Cooperative monitoring for Humboldt squid could include training in species identification and sea condition reporting in logbooks. Future "invasions" are likely, and more eyes on the water will improve our understanding of the behavior and impacts of Humboldt squid on coastal resources. Close

• 482. [Article] Post-occupancy Evaluation at the Zoo: Behavioral and Hormonal Indicators of Welfare in Orangutans (Pongo pygmaeus abelii)

  An increased understanding of species-specific behavioral needs has lead zoos to focus on providing more naturalistic and stimulating environments. Scientific assessments of how changes in habitat affect ...

  Citation × Citation Citation Abstract Copy Title: Post-occupancy Evaluation at the Zoo: Behavioral and Hormonal Indicators of Welfare in Orangutans (Pongo pygmaeus abelii) Author: Tingey, Leigha Year: 2012 An increased understanding of species-specific behavioral needs has lead zoos to focus on providing more naturalistic and stimulating environments. Scientific assessments of how changes in habitat affect animal behavior are necessary in improving overall animal welfare. This study examined the move of three orangutans housed at the Oregon Zoo into a new and innovative exhibit. Post-occupancy evaluation (POE), which offers systematic information regarding the success or failure of the built environment (Maple & Finlay, 1987), was utilized to effectively evaluate the results of the move. The collection of behavioral data and adrenal activity monitoring through collection of non-invasive saliva, urine and hair provided a comprehensive methodology for comparing changes in behavior and physiological functioning. Behavioral results showed that following the move to the new enclosure animals spent less time inactive, more time at higher elevations and utilized exhibit structures at a greater frequency. Hormonal results suggest that detection of cortisol in orangutan hair could be a useful tool for monitoring chronic stress. Title: Post-occupancy Evaluation at the Zoo: Behavioral and Hormonal Indicators of Welfare in Orangutans (Pongo pygmaeus abelii) Author: Tingey, Leigha Year: 2012 An increased understanding of species-specific behavioral needs has lead zoos to focus on providing more naturalistic and stimulating environments. Scientific assessments of how changes in habitat affect animal behavior are necessary in improving overall animal welfare. This study examined the move of three orangutans housed at the Oregon Zoo into a new and innovative exhibit. Post-occupancy evaluation (POE), which offers systematic information regarding the success or failure of the built environment (Maple & Finlay, 1987), was utilized to effectively evaluate the results of the move. The collection of behavioral data and adrenal activity monitoring through collection of non-invasive saliva, urine and hair provided a comprehensive methodology for comparing changes in behavior and physiological functioning. Behavioral results showed that following the move to the new enclosure animals spent less time inactive, more time at higher elevations and utilized exhibit structures at a greater frequency. Hormonal results suggest that detection of cortisol in orangutan hair could be a useful tool for monitoring chronic stress. Close

• 483. [Article] Identification of invasive and reemerging pests on hazelnuts

  Published December 2007. Reviewed July 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: Identification of invasive and reemerging pests on hazelnuts Author: Chambers, U. (Ute), Walton, V. M. (Vaughn Martin), Dreves, A., Oregon State University. Extension Service, Bruck, D. J., Olsen, J. Published December 2007. Reviewed July 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Identification of invasive and reemerging pests on hazelnuts Author: Chambers, U. (Ute), Walton, V. M. (Vaughn Martin), Dreves, A., Oregon State University. Extension Service, Bruck, D. J., Olsen, J. Published December 2007. Reviewed July 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 484. [Article] Non-spatial and spatial models for multi-host pathogen spread in competing species : applications to barley yellow dwarf virus and rinderpest

  Modeling and analyzing the combined effects of disease and population dynamics is important in understanding the effects of mechanisms such as pathogen transmission and direct competition between host ...

  Citation × Citation Citation Abstract Copy Title: Non-spatial and spatial models for multi-host pathogen spread in competing species : applications to barley yellow dwarf virus and rinderpest Author: Manore, Carrie Anna Modeling and analyzing the combined effects of disease and population dynamics is important in understanding the effects of mechanisms such as pathogen transmission and direct competition between host species on the distribution and abundance of different species in an ecological community. Mathematical analysis of such models in a spatially explicit environment gives additional important insight into these systems. Motivated by our participation in the IGERT Ecosystem Informatics program, we explore the interactions between and among disease, competition, and spatial heterogeneity from a mathematical modeling perspective. In particular, we formulate a model in which two species compete directly via Lotka-Volterra competition and share a directly transmitted pathogen via both mass action (density-dependent) and frequency-dependent incidence. We determine conditions under which the pathogen is endemic as well as conditions for long-term coexistence of the two species and the pathogen. As the interior equilibria are intractable, we examine a special case for which full stability analysis is possible. We show that in this case, mass action and frequency incidence behave qualitatively the same. We prove existence, uniqueness, and stability for the full model with frequency incidence under the assumption of no death due to disease using theory of asymptotically autonomous equations. Using persistence theory, we show that for the full model with mass action, if all boundary equilibria are unstable, then both species and the pathogen persist uniformly strongly. We extend the multi-host competition-disease model to include multiple patches in order to model Barley Yellow Dwarf Virus in native grasslands. Our results suggest that connectivity can interact with arrival time and host infection tolerance to determine the success or failure of an invasion. Lastly, we simulate the spread of the multi-host virus rinderpest in livestock across the United States, finding that the outcome varies greatly with the starting location of the epidemic. Title: Non-spatial and spatial models for multi-host pathogen spread in competing species : applications to barley yellow dwarf virus and rinderpest Author: Manore, Carrie Anna Modeling and analyzing the combined effects of disease and population dynamics is important in understanding the effects of mechanisms such as pathogen transmission and direct competition between host species on the distribution and abundance of different species in an ecological community. Mathematical analysis of such models in a spatially explicit environment gives additional important insight into these systems. Motivated by our participation in the IGERT Ecosystem Informatics program, we explore the interactions between and among disease, competition, and spatial heterogeneity from a mathematical modeling perspective. In particular, we formulate a model in which two species compete directly via Lotka-Volterra competition and share a directly transmitted pathogen via both mass action (density-dependent) and frequency-dependent incidence. We determine conditions under which the pathogen is endemic as well as conditions for long-term coexistence of the two species and the pathogen. As the interior equilibria are intractable, we examine a special case for which full stability analysis is possible. We show that in this case, mass action and frequency incidence behave qualitatively the same. We prove existence, uniqueness, and stability for the full model with frequency incidence under the assumption of no death due to disease using theory of asymptotically autonomous equations. Using persistence theory, we show that for the full model with mass action, if all boundary equilibria are unstable, then both species and the pathogen persist uniformly strongly. We extend the multi-host competition-disease model to include multiple patches in order to model Barley Yellow Dwarf Virus in native grasslands. Our results suggest that connectivity can interact with arrival time and host infection tolerance to determine the success or failure of an invasion. Lastly, we simulate the spread of the multi-host virus rinderpest in livestock across the United States, finding that the outcome varies greatly with the starting location of the epidemic. Close

• 485. [Image] Research information needs on terrestrial vertebrate species of the interior Columbia River basin and northern portions of the Klamath and Great basins: research, development, and application database

  	"September 1997"; Includes bibliographical references (p. 24)
  	Citation × Citation Citation Abstract Copy Title: Research information needs on terrestrial vertebrate species of the interior Columbia River basin and northern portions of the Klamath and Great basins: research, development, and application database Author: Marcot, Bruce G. Year: 1997, 2005, 2004 "September 1997"; Includes bibliographical references (p. 24) Title: Research information needs on terrestrial vertebrate species of the interior Columbia River basin and northern portions of the Klamath and Great basins: research, development, and application database Author: Marcot, Bruce G. Year: 1997, 2005, 2004 "September 1997"; Includes bibliographical references (p. 24) Close

• 486. [Article] Soil community dynamics in sagebrush and cheatgrass-invaded ecosystems of the northern Great Basin

  Sagebrush steppe ecosystems in the Great Basin have become increasingly threatened by the proliferation of cheatgrass (Bromus tectorum L.), an invasive annual grass. Diverse sagebrush and perennial bunchgrass ...

  Citation × Citation Citation Abstract Copy Title: Soil community dynamics in sagebrush and cheatgrass-invaded ecosystems of the northern Great Basin Author: DeCrappeo, Nicole M. Sagebrush steppe ecosystems in the Great Basin have become increasingly threatened by the proliferation of cheatgrass (Bromus tectorum L.), an invasive annual grass. Diverse sagebrush and perennial bunchgrass landscapes can be converted to homogenous cheatgrass grasslands mainly through the effects of fire. Although the consequences of this conversion are well understood in the context of plant community dynamics, information on changes to soil communities has not been well documented. I characterized soil surface, microbial, and nematode community dynamics in sagebrush steppe and cheatgrass-invaded areas across the northern Great Basin. I also examined how restoration treatments, such as seeding with a low impact rangeland drill and applying herbicide or sugar to plots, affected soil communities. Soil community functional diversity and structure were alike at sites where soil pH and percent bare ground were similar. Rangeland drill seeding and associated human trampling decreased biological soil crust cover at sites with high proportions of cyanobacteria. Herbicide treatments had little effect on soil communities, but addition of sugar to plots increased carbohydrate utilization and fungal biomass of cheatgrass- invaded soils. In studying paired intact and cheatgrass-invaded sagebrush plots, I found that microbial functional diversity and community composition were different in sagebrush, bunchgrass, cheatgrass, and interspace soils. Fungal biomass and species richness were highest under sagebrush and decreased under cheatgrass. To examine how soil community shifts might affect ecosystem processes, I investigated the contribution of fungi to inorganic nitrogen (N) mineralization in sagebrush and cheatgrass rhizospheres. Results from a ¹⁵N pool dilution experiment modified with the fungal protein synthesis inhibitor cycloheximide showed that gross and net N cycling rates did not differ between control sagebrush and cheatgrass soils and that fungi were important for gross NH₄⁺ production and consumption in both soil types. However, net nitrification increased in sagebrush soils after 24 h, suggesting that when organic matter decomposition by fungi ceased bacteria became carbon limited and could no longer assimilate NH₄⁺. These studies demonstrate that cheatgrass invasion into sagebrush steppe ecosystems can bring about significant changes to soil communities and that these changes may have repercussions for ecosystem functioning in the northern Great Basin. Title: Soil community dynamics in sagebrush and cheatgrass-invaded ecosystems of the northern Great Basin Author: DeCrappeo, Nicole M. Sagebrush steppe ecosystems in the Great Basin have become increasingly threatened by the proliferation of cheatgrass (Bromus tectorum L.), an invasive annual grass. Diverse sagebrush and perennial bunchgrass landscapes can be converted to homogenous cheatgrass grasslands mainly through the effects of fire. Although the consequences of this conversion are well understood in the context of plant community dynamics, information on changes to soil communities has not been well documented. I characterized soil surface, microbial, and nematode community dynamics in sagebrush steppe and cheatgrass-invaded areas across the northern Great Basin. I also examined how restoration treatments, such as seeding with a low impact rangeland drill and applying herbicide or sugar to plots, affected soil communities. Soil community functional diversity and structure were alike at sites where soil pH and percent bare ground were similar. Rangeland drill seeding and associated human trampling decreased biological soil crust cover at sites with high proportions of cyanobacteria. Herbicide treatments had little effect on soil communities, but addition of sugar to plots increased carbohydrate utilization and fungal biomass of cheatgrass- invaded soils. In studying paired intact and cheatgrass-invaded sagebrush plots, I found that microbial functional diversity and community composition were different in sagebrush, bunchgrass, cheatgrass, and interspace soils. Fungal biomass and species richness were highest under sagebrush and decreased under cheatgrass. To examine how soil community shifts might affect ecosystem processes, I investigated the contribution of fungi to inorganic nitrogen (N) mineralization in sagebrush and cheatgrass rhizospheres. Results from a ¹⁵N pool dilution experiment modified with the fungal protein synthesis inhibitor cycloheximide showed that gross and net N cycling rates did not differ between control sagebrush and cheatgrass soils and that fungi were important for gross NH₄⁺ production and consumption in both soil types. However, net nitrification increased in sagebrush soils after 24 h, suggesting that when organic matter decomposition by fungi ceased bacteria became carbon limited and could no longer assimilate NH₄⁺. These studies demonstrate that cheatgrass invasion into sagebrush steppe ecosystems can bring about significant changes to soil communities and that these changes may have repercussions for ecosystem functioning in the northern Great Basin. Close

• 487. [Article] Vegetation and Small Mammal Responses to Western Juniper (Juniperus occidentalis) Control in Eastern Oregon

  Shrub-steppe ecosystems of western North America provide habitat for many wildlife species, are important components of public and private rangelands, and offer recreational opportunities for millions ...

  Citation × Citation Citation Abstract Copy Title: Vegetation and Small Mammal Responses to Western Juniper (Juniperus occidentalis) Control in Eastern Oregon Author: Morozumi, Corinne N. Shrub-steppe ecosystems of western North America provide habitat for many wildlife species, are important components of public and private rangelands, and offer recreational opportunities for millions of people. They are some of the most vulnerable ecosystems in the United States and have been altered by human activities such as livestock grazing, active fire suppression, conversion to agriculture, and urbanization of the west. Since the late 1800s woody encroachment of piñon-juniper species has also contributed to the loss of shrub-steppe habitat. Presently, land managers remove woody tree species in order to recover shrub-steppe although it is unclear how responses to these management activities differ due to site-specific conditions and existing woodland development. I studied post juniper-thinning responses in eastern Oregon at a wildlife area important as winter range for mule deer (Odocoileus hemionus). I investigated vegetative responses to western juniper (Juniperus occidentalis) thinning across a woodland development gradient and tested for interactive effects of juniper cutting and cattle exclusion. In addition, I explored plant and small mammal successional dynamics after juniper thinning and examined plant community responses within microhabitats created by the felled trees. I compared vegetative responses to juniper thinning as well as cattle exclusion among sites where juniper were subordinate (Phase I), co-dominant (Phase II), and dominant to shrubs and grasses (Phase III, sensu Miller et al. 2005). At the Phase I site, thinning did not increase herbaceous biomass while thinned plots at the Phase II site had 2.71 times more median herbaceous biomass (99.17% CI: 1.37 to 5.37 times more biomass) than unthinned plots. Conversely, herbaceous biomass at the Phase III juniper woodland site was 0.36 times lower in thinned plots when compared to unthinned plots (99.17% CI: 0.17 to 0.78 times less biomass). Unfortunately, many of the responses were driven by exotic species release. Where juniper were subordinate (Phase I), mean percent cover by exotic grass increased by 24.58 percentage points in thinned plots as compared to unthinned plots (98.30% CI: 0.27 to 48.90 percentage points higher). Thinning at the Phase II site increased mean exotic grass cover by an estimated 28.47 percentage points as compared to mean exotic cover in the same plots before treatment (98.30% CI: 4.15 to 52.79 percentage points higher cover). Median native bunchgrass cover at this site was 5.06 times greater after juniper treatment (99.7% CI: 1.78 to 14.35 times higher percent cover). I found few main or interactive effects of cattle exclosure after one year of treatment. Responses to grazing exclosure may take longer to develop. These results indicate that sites within the wildlife area respond differently to juniper management and that exotic grass control will be key to successful shrub-steppe recovery. In addition, I used a time-since-juniper thinning chronoseries consisting of plots cut in 2008, 2009, 2010, 2012, and an adjacent uncut control to explore how shrub-steppe flora and fauna are responding to juniper treatment through time. Shrub cover and seedling density were low in each plot. I recorded the highest seedling abundance (mean of 0.25 seedlings) in the uncut control plot. Median grass cover in the uncut control was 9.50% while in the most recently treated plot (2012) it was 26.75%. Small mammal relative abundance and diversity was low across all time-since-treatment plots though highest in the plot with the greatest time-since-treatment. Deer mouse (Peromyscus maniculatus) was the most abundant species in all plots and accounted for 70-95% of all unique captures. Least chipmunk (Tamias minimus) were present in the plot with greatest time-since-treatment indicating the potential recovery of key native shrubs since these small mammals perform an important seed dispersal role. I also investigated how potential microhabitats created by the felled juniper might support different plant communities. I assessed plant responses within zones created by 1) the felled tree (canopy zone), 2) the original duff zone, and 3) the between - tree interspace zone. The three zones had different plant community compositions as analyzed multivariately with non-metric multidimensional scaling (NMS). Canopy and duff zones were forb - dominated and had less exotic grass invasion while interspace zones were heavily invested with medusahead (Taeniatherum caput-medusae) and ventenata (Ventenata dubia). Exotic herbaceous productivity was lowest under the standing trees of the control plot and high in the interspace of all plots with juniper thinning. In the 2012 cut plot, grass cover was 27.90 percentage points less in the canopy zone compared to the interspace zone (98.75% CI: 17.64 to 38.16 percentage points less grass cover). In the uncut control, median native biomass was 2.08 times greater under the standing trees compared to the interspace (96.25% CI: 1.09 to 3.97 times more biomass). Results from the time-since-treatment chronoseries indicated that exotic grass dominance might be limiting shrub-steppe recovery. Active restoration of shrubs and native grasses may be necessary to address the dominance of exotic grass after juniper thinning. Positive signs of habitat recovery included small mammal responses though I was unable to calculate population estimates due to plot size. Title: Vegetation and Small Mammal Responses to Western Juniper (Juniperus occidentalis) Control in Eastern Oregon Author: Morozumi, Corinne N. Shrub-steppe ecosystems of western North America provide habitat for many wildlife species, are important components of public and private rangelands, and offer recreational opportunities for millions of people. They are some of the most vulnerable ecosystems in the United States and have been altered by human activities such as livestock grazing, active fire suppression, conversion to agriculture, and urbanization of the west. Since the late 1800s woody encroachment of piñon-juniper species has also contributed to the loss of shrub-steppe habitat. Presently, land managers remove woody tree species in order to recover shrub-steppe although it is unclear how responses to these management activities differ due to site-specific conditions and existing woodland development. I studied post juniper-thinning responses in eastern Oregon at a wildlife area important as winter range for mule deer (Odocoileus hemionus). I investigated vegetative responses to western juniper (Juniperus occidentalis) thinning across a woodland development gradient and tested for interactive effects of juniper cutting and cattle exclusion. In addition, I explored plant and small mammal successional dynamics after juniper thinning and examined plant community responses within microhabitats created by the felled trees. I compared vegetative responses to juniper thinning as well as cattle exclusion among sites where juniper were subordinate (Phase I), co-dominant (Phase II), and dominant to shrubs and grasses (Phase III, sensu Miller et al. 2005). At the Phase I site, thinning did not increase herbaceous biomass while thinned plots at the Phase II site had 2.71 times more median herbaceous biomass (99.17% CI: 1.37 to 5.37 times more biomass) than unthinned plots. Conversely, herbaceous biomass at the Phase III juniper woodland site was 0.36 times lower in thinned plots when compared to unthinned plots (99.17% CI: 0.17 to 0.78 times less biomass). Unfortunately, many of the responses were driven by exotic species release. Where juniper were subordinate (Phase I), mean percent cover by exotic grass increased by 24.58 percentage points in thinned plots as compared to unthinned plots (98.30% CI: 0.27 to 48.90 percentage points higher). Thinning at the Phase II site increased mean exotic grass cover by an estimated 28.47 percentage points as compared to mean exotic cover in the same plots before treatment (98.30% CI: 4.15 to 52.79 percentage points higher cover). Median native bunchgrass cover at this site was 5.06 times greater after juniper treatment (99.7% CI: 1.78 to 14.35 times higher percent cover). I found few main or interactive effects of cattle exclosure after one year of treatment. Responses to grazing exclosure may take longer to develop. These results indicate that sites within the wildlife area respond differently to juniper management and that exotic grass control will be key to successful shrub-steppe recovery. In addition, I used a time-since-juniper thinning chronoseries consisting of plots cut in 2008, 2009, 2010, 2012, and an adjacent uncut control to explore how shrub-steppe flora and fauna are responding to juniper treatment through time. Shrub cover and seedling density were low in each plot. I recorded the highest seedling abundance (mean of 0.25 seedlings) in the uncut control plot. Median grass cover in the uncut control was 9.50% while in the most recently treated plot (2012) it was 26.75%. Small mammal relative abundance and diversity was low across all time-since-treatment plots though highest in the plot with the greatest time-since-treatment. Deer mouse (Peromyscus maniculatus) was the most abundant species in all plots and accounted for 70-95% of all unique captures. Least chipmunk (Tamias minimus) were present in the plot with greatest time-since-treatment indicating the potential recovery of key native shrubs since these small mammals perform an important seed dispersal role. I also investigated how potential microhabitats created by the felled juniper might support different plant communities. I assessed plant responses within zones created by 1) the felled tree (canopy zone), 2) the original duff zone, and 3) the between - tree interspace zone. The three zones had different plant community compositions as analyzed multivariately with non-metric multidimensional scaling (NMS). Canopy and duff zones were forb - dominated and had less exotic grass invasion while interspace zones were heavily invested with medusahead (Taeniatherum caput-medusae) and ventenata (Ventenata dubia). Exotic herbaceous productivity was lowest under the standing trees of the control plot and high in the interspace of all plots with juniper thinning. In the 2012 cut plot, grass cover was 27.90 percentage points less in the canopy zone compared to the interspace zone (98.75% CI: 17.64 to 38.16 percentage points less grass cover). In the uncut control, median native biomass was 2.08 times greater under the standing trees compared to the interspace (96.25% CI: 1.09 to 3.97 times more biomass). Results from the time-since-treatment chronoseries indicated that exotic grass dominance might be limiting shrub-steppe recovery. Active restoration of shrubs and native grasses may be necessary to address the dominance of exotic grass after juniper thinning. Positive signs of habitat recovery included small mammal responses though I was unable to calculate population estimates due to plot size. Close

• 488. [Article] Predator Exclosures, Predator Removal, and Habitat Improvement Increase Nest Success of Snowy Plovers in Oregon, USA

  Management to increase reproductive success is commonly used to aid recovery of threatened and endangered species. The Western Snowy Plover (Charadrius nivosus nivosus) breeds from coastal Washington, ...

  Citation × Citation Citation Abstract Copy Title: Predator Exclosures, Predator Removal, and Habitat Improvement Increase Nest Success of Snowy Plovers in Oregon, USA Author: Dinsmore, Stephen J., Lauten, David J., Castelein, Kathleen J., Gaines, Eleanor P., Stern, Mark A. Year: 2014 Management to increase reproductive success is commonly used to aid recovery of threatened and endangered species. The Western Snowy Plover (Charadrius nivosus nivosus) breeds from coastal Washington, USA, to Baja California, Mexico, and in disjunct interior sites. The Pacific coast population is federally listed as Threatened; habitat loss and nest loss to a suite of terrestrial and avian predators are thought to be primary factors limiting population growth in this species. In coastal Oregon, USA, a consortium of state and federal management agencies deployed nest exclosures on active Snowy Plover nests, initiated a lethal predator management program, and conducted local-scale habitat management in an effort to boost local productivity. During 1990–2009, we monitored 1,951 Snowy Plover nests at 9 sites with varying treatments. We examined the effectiveness of 3 types of nest exclosures (large, small, and outfitted with electric wire), predator removal, and habitat management on nest survival. Habitat management to remove invasive grasses and provide more suitable nesting substrate more than doubled nest survival. Predator management or use of any of the 3 types of exclosures also affected nest survival. There appeared to be no additional benefit to using both approaches, but the biological relevance of these findings is unclear because of site differences in treatments applied. Importantly, these management techniques only affected nesting success; their effect on other contributions to population viability (e.g., fledging success) was not correlated with nesting success. This long-term study illustrates the short-term benefits and tradeoffs of using nest exclosures, predator management, and habitat restoration to improve nesting success. Although we gained broader insight into the relative efficacy of common management techniques to improve avian nesting success, we cannot yet determine how improved nest success contributes to population growth. Title: Predator Exclosures, Predator Removal, and Habitat Improvement Increase Nest Success of Snowy Plovers in Oregon, USA Author: Dinsmore, Stephen J., Lauten, David J., Castelein, Kathleen J., Gaines, Eleanor P., Stern, Mark A. Year: 2014 Management to increase reproductive success is commonly used to aid recovery of threatened and endangered species. The Western Snowy Plover (Charadrius nivosus nivosus) breeds from coastal Washington, USA, to Baja California, Mexico, and in disjunct interior sites. The Pacific coast population is federally listed as Threatened; habitat loss and nest loss to a suite of terrestrial and avian predators are thought to be primary factors limiting population growth in this species. In coastal Oregon, USA, a consortium of state and federal management agencies deployed nest exclosures on active Snowy Plover nests, initiated a lethal predator management program, and conducted local-scale habitat management in an effort to boost local productivity. During 1990–2009, we monitored 1,951 Snowy Plover nests at 9 sites with varying treatments. We examined the effectiveness of 3 types of nest exclosures (large, small, and outfitted with electric wire), predator removal, and habitat management on nest survival. Habitat management to remove invasive grasses and provide more suitable nesting substrate more than doubled nest survival. Predator management or use of any of the 3 types of exclosures also affected nest survival. There appeared to be no additional benefit to using both approaches, but the biological relevance of these findings is unclear because of site differences in treatments applied. Importantly, these management techniques only affected nesting success; their effect on other contributions to population viability (e.g., fledging success) was not correlated with nesting success. This long-term study illustrates the short-term benefits and tradeoffs of using nest exclosures, predator management, and habitat restoration to improve nesting success. Although we gained broader insight into the relative efficacy of common management techniques to improve avian nesting success, we cannot yet determine how improved nest success contributes to population growth. Close

• 489. [Article] Fire-Vegetation Feedbacks and Alternative States: Common Mechanisms of Temperate Forest Vulnerability to Fire in Southern South America and New Zealand

  In the context of global warming and increasing impacts of invasive plants and animals, we examine how positive fire–vegetation feedbacks are increasing the vulnerability of pyrophobic temperate forests ...

  Citation × Citation Citation Abstract Copy Title: Fire-Vegetation Feedbacks and Alternative States: Common Mechanisms of Temperate Forest Vulnerability to Fire in Southern South America and New Zealand Author: Kitzberger, T, Perry, G. L.W., Paritsis, J., Gowda, J. H. Year: 2016 In the context of global warming and increasing impacts of invasive plants and animals, we examine how positive fire–vegetation feedbacks are increasing the vulnerability of pyrophobic temperate forests to conversion to pyrophytic non-forest vegetation in southern South America and New Zealand. We extensively review the relevant literature to reveal how these temperate southern hemisphere floras have generated similar positive fire–vegetation feedback mechanisms resulting in increased vulnerability to anthropogenically altered fire regimens. For the two regions, we address the following questions. 1. What are the major plant species, physiognomic types and functional types characteristic of pyrophytic versus pyrophobic vegetation types and how do their traits affect flammability, resistance to fire and recovery after fire? 2. What are the roles of herbivory and microclimate in enhancing fire–vegetation feedbacks? 3. Are there similarities in trends of cover type transitions in relation to altered fire regimens? 4. How are climate change, land-use trends and the effects of introduced plants and animals affecting the vulnerability of these ecosystems to fire-induced transitions to alternative stable states? Most temperate forests of New Zealand and southern South America evolved under conditions of low fire frequencies so few taxa became adapted to recurrent fire. Current dichotomous landscapes consisting of juxtaposed pyrophobic and pyrophytic vegetation types are the outcome of the expansion of fire-resilient and fire-promoting species associated with the arrival of humans. Despite considerable differences in human history and biogeographic history, the case studies presented here show remarkable parallels in life-history traits of the key pyrophobic taxa, fire–vegetation feedback mechanisms, overall ecosystem responses to anthropogenic alteration of fire regimens, and likely vulnerability to expected global change influences on future fire regimens. Title: Fire-Vegetation Feedbacks and Alternative States: Common Mechanisms of Temperate Forest Vulnerability to Fire in Southern South America and New Zealand Author: Kitzberger, T, Perry, G. L.W., Paritsis, J., Gowda, J. H. Year: 2016 In the context of global warming and increasing impacts of invasive plants and animals, we examine how positive fire–vegetation feedbacks are increasing the vulnerability of pyrophobic temperate forests to conversion to pyrophytic non-forest vegetation in southern South America and New Zealand. We extensively review the relevant literature to reveal how these temperate southern hemisphere floras have generated similar positive fire–vegetation feedback mechanisms resulting in increased vulnerability to anthropogenically altered fire regimens. For the two regions, we address the following questions. 1. What are the major plant species, physiognomic types and functional types characteristic of pyrophytic versus pyrophobic vegetation types and how do their traits affect flammability, resistance to fire and recovery after fire? 2. What are the roles of herbivory and microclimate in enhancing fire–vegetation feedbacks? 3. Are there similarities in trends of cover type transitions in relation to altered fire regimens? 4. How are climate change, land-use trends and the effects of introduced plants and animals affecting the vulnerability of these ecosystems to fire-induced transitions to alternative stable states? Most temperate forests of New Zealand and southern South America evolved under conditions of low fire frequencies so few taxa became adapted to recurrent fire. Current dichotomous landscapes consisting of juxtaposed pyrophobic and pyrophytic vegetation types are the outcome of the expansion of fire-resilient and fire-promoting species associated with the arrival of humans. Despite considerable differences in human history and biogeographic history, the case studies presented here show remarkable parallels in life-history traits of the key pyrophobic taxa, fire–vegetation feedback mechanisms, overall ecosystem responses to anthropogenic alteration of fire regimens, and likely vulnerability to expected global change influences on future fire regimens. Close

• 490. [Article] Interactive Physiological Responses of Nile Tilapia to Salinity- and Temperature-induced Stress: Quantifying the Regulation of Apoptosis and Cell Cycle Arrest in Oreochromis Niloticus

  Nile tilapia provide an ideal model to study the accumulation of climate change-induced stressors due to their habitat in tropical freshwater systems that are susceptible to salt water invasion and temperature ...

  Citation × Citation Citation Abstract Copy Title: Interactive Physiological Responses of Nile Tilapia to Salinity- and Temperature-induced Stress: Quantifying the Regulation of Apoptosis and Cell Cycle Arrest in Oreochromis Niloticus Author: McGuire, Charlee Year: 2017 Nile tilapia provide an ideal model to study the accumulation of climate change-induced stressors due to their habitat in tropical freshwater systems that are susceptible to salt water invasion and temperature fluctuation due to sea level rise. This study investigates the physiological responses of Nile tilapia to salinity- and temperature-induced stress to identify the interactive effects of simultaneous stressors on the cell cycle. Proteins indicative of cell cycle activity and arrest were quantified in the tissues of Nile tilapia exposed to various environmental conditions varying by temperature and salinity. Dot Blotting was utilized to measure Gadd45 while Western Blotting was used to confirm the identity of the protein. Results from previous investigations in the Buckley lab were also utilized to compare the expression patterns of Gadd45 to relevant cell activity proteins p53 and PCNA. Of the three proteins under scrutiny, a significant change in expression of p53 was observed for the interaction of salinity- and temperature- induced stress, while full strength saltwater treatment alone was found to have a significant impact on the expression of p53, Gadd45 and PCNA. These findings can be used in collaboration with existing studies to describe the coordination of apoptotic pathways in Nile tilapia and other non-mammalian species, as well as to create policy on how to conserve this important species effectively both in the wild and in fisheries for aquaculture, commercial and public health initiatives in response to global climate change. Title: Interactive Physiological Responses of Nile Tilapia to Salinity- and Temperature-induced Stress: Quantifying the Regulation of Apoptosis and Cell Cycle Arrest in Oreochromis Niloticus Author: McGuire, Charlee Year: 2017 Nile tilapia provide an ideal model to study the accumulation of climate change-induced stressors due to their habitat in tropical freshwater systems that are susceptible to salt water invasion and temperature fluctuation due to sea level rise. This study investigates the physiological responses of Nile tilapia to salinity- and temperature-induced stress to identify the interactive effects of simultaneous stressors on the cell cycle. Proteins indicative of cell cycle activity and arrest were quantified in the tissues of Nile tilapia exposed to various environmental conditions varying by temperature and salinity. Dot Blotting was utilized to measure Gadd45 while Western Blotting was used to confirm the identity of the protein. Results from previous investigations in the Buckley lab were also utilized to compare the expression patterns of Gadd45 to relevant cell activity proteins p53 and PCNA. Of the three proteins under scrutiny, a significant change in expression of p53 was observed for the interaction of salinity- and temperature- induced stress, while full strength saltwater treatment alone was found to have a significant impact on the expression of p53, Gadd45 and PCNA. These findings can be used in collaboration with existing studies to describe the coordination of apoptotic pathways in Nile tilapia and other non-mammalian species, as well as to create policy on how to conserve this important species effectively both in the wild and in fisheries for aquaculture, commercial and public health initiatives in response to global climate change. Close