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• 61. [Article] Comparative Characterization of Two Nearshore Rocky Reef Areas: A high-use recreational fishing reef vs. an unfished reef

  This project has provided the ODFW Marine Habitat Project with a unique opportunity to make a comparative examination of the habitats and fish communities of a heavily fished reef off of Siletz Bay, and ...

  Citation × Citation Citation Abstract Copy Title: Comparative Characterization of Two Nearshore Rocky Reef Areas: A high-use recreational fishing reef vs. an unfished reef Author: Merems, Arlene, Appy, Marcus, Romsos, Chris, Weeks, Hal, Fox, David, Amend, Mark This project has provided the ODFW Marine Habitat Project with a unique opportunity to make a comparative examination of the habitats and fish communities of a heavily fished reef off of Siletz Bay, and a nearly unfished reef off Cape Perpetua. There are over 17,000 angler trips for groundfish out of Depoe Bay annually, many choosing to fish Siletz Reef. In addition, numerous whale watching and sightseeing charter vessels operate in the vicinity of the reef. Cape Perpetua Reef consists of isolated patches of rock, and is too far from Newport (the nearest port) to receive much fishing effort. This examination of the influences of fishing pressure in nearshore rocky habitat complements, and is embedded in, a broader effort to understand the distribution and character of Oregon’s nearshore rocky reefs, and the species that are dependent upon them for habitat. The ODFW Marine Habitat Project has spent the last eight years working in cooperation with scientists and other resource agencies to develop methods for classifying and mapping nearshore rocky reefs habitats off Oregon. Because nearshore reefs are in state waters, Oregon is responsible for managing these living resources and habitats to sustain their long-term use and productivity. To date, eight reefs have been surveyed and mapped with sidescan and/or multibeam bathymetry at a resolution indicative of fish habitat. ODFW has also been developing non-extractive fish survey techniques to describe fish-habitat associations and estimate fish abundance at the habitat and reef scale. The importance of habitat to reef species cannot be over-stated and is now widely accepted in the scientific community and is the focus of major research efforts in other Pacific coastal states. Better understanding of the degree to which harvest influences relative and absolute abundance, combined with species-habitat relationships, is essential for resource managers to exercise their stewardship responsibilities to protect 5 essential habitat, develop population indices for species at risk, and maintain healthy and productive ecological systems. Title: Comparative Characterization of Two Nearshore Rocky Reef Areas: A high-use recreational fishing reef vs. an unfished reef Author: Merems, Arlene, Appy, Marcus, Romsos, Chris, Weeks, Hal, Fox, David, Amend, Mark This project has provided the ODFW Marine Habitat Project with a unique opportunity to make a comparative examination of the habitats and fish communities of a heavily fished reef off of Siletz Bay, and a nearly unfished reef off Cape Perpetua. There are over 17,000 angler trips for groundfish out of Depoe Bay annually, many choosing to fish Siletz Reef. In addition, numerous whale watching and sightseeing charter vessels operate in the vicinity of the reef. Cape Perpetua Reef consists of isolated patches of rock, and is too far from Newport (the nearest port) to receive much fishing effort. This examination of the influences of fishing pressure in nearshore rocky habitat complements, and is embedded in, a broader effort to understand the distribution and character of Oregon’s nearshore rocky reefs, and the species that are dependent upon them for habitat. The ODFW Marine Habitat Project has spent the last eight years working in cooperation with scientists and other resource agencies to develop methods for classifying and mapping nearshore rocky reefs habitats off Oregon. Because nearshore reefs are in state waters, Oregon is responsible for managing these living resources and habitats to sustain their long-term use and productivity. To date, eight reefs have been surveyed and mapped with sidescan and/or multibeam bathymetry at a resolution indicative of fish habitat. ODFW has also been developing non-extractive fish survey techniques to describe fish-habitat associations and estimate fish abundance at the habitat and reef scale. The importance of habitat to reef species cannot be over-stated and is now widely accepted in the scientific community and is the focus of major research efforts in other Pacific coastal states. Better understanding of the degree to which harvest influences relative and absolute abundance, combined with species-habitat relationships, is essential for resource managers to exercise their stewardship responsibilities to protect 5 essential habitat, develop population indices for species at risk, and maintain healthy and productive ecological systems. Close

• 62. [Article] Woody riparian species patterns along northeast Oregon mountainous streams and the relationship to riparian capability

  Woody riparian vegetation is an essential component of riparian ecosystems, responsible in part for the maintenance of functional ecological processes. The plant community composition and distribution ...

  Citation × Citation Citation Abstract Copy Title: Woody riparian species patterns along northeast Oregon mountainous streams and the relationship to riparian capability Author: Yancey, Jennifer M. Woody riparian vegetation is an essential component of riparian ecosystems, responsible in part for the maintenance of functional ecological processes. The plant community composition and distribution provide an indication of the underlying mosaic of environmental attributes and processes. Restoration and management of riparian communities have been hindered by the lack of measurable criteria for the assessment of a riparian systems modified by human imposed infrastructures. The woody vegetation community offered a quantifiable indicator of the underlying mosaic of environmental, physical, and hydrological attributes, while allowing the investigation of the concept of riparian potential versus riparian capability. The examination of riparian condition was measured through the determination of species-environmental relationships along three mountainous channels in northeast Oregon. The physical and environmental attributes of channel morphology, hydrology, understory community composition, surface particle characteristics, and microclimate variables were quantified and analyzed in relation to the woody vegetation composition and distribution across the three separate streams and within flood-frequency elevation zones. The second component of the study evaluated and described methods for quantifying the concept of riparian capability, based on the measured species-environmental relationships and channel morphology. The evaluation of condition was measured against the reference baseline of Rosgen hierarchical classification and regional hydraulic geometry curves. Multivariate analyses indicated that vegetation transects grouped by stream and vegetation belt transects weakly grouped by flood zone, based on the species composition quantified within the vegetation transects and flood zones. Secondly, channel geometry, canopy cover, air temperature, channel particle size, understory composition attributes, and flood zone distance were found to be overall gradients, which described the variation in species composition across the three streams in northeast Oregon. Direct individual species-environmental relationship conclusions were weak due to the close clustering of species and multiple physical and environmental gradients. Riparian condition at the Grande Ronde River and North Fork Catherine Creek was determined to be functioning at riparian capability. Channel geometry measurements at the two stream reaches aligned with Rosgen stream type criteria and regional hydrologic curves, while species composition represented characteristics of potential natural communities. Meadow Creek was concluded to have departed from the highest attainable condition, thus riparian condition was less than capability. The results suggested that woody riparian vegetation response was a function the physical sttributes: channel morphological widths, bankfull, floodprone, 25-year flood width, valley width, channel sinuosity, and channel slope. Environmental attributes, floodplain canopy cover, air temperature, and understory composition, were further factors that influenced the woody riparian vegetation community variation. The results also suggested species richness and diversity were associated with specific physical and environmental attributes. Finally, the results provided the determination of riparian capability along montane streams in northeast Oregon and criteria acceptable for the determination of riparian capability. These criteria included the physical channel measurements assessed against Rosgen hierarchiecal classification and regional channel geometry curves; and woody vegetation presence and distribution assessed against potential natural community plant associations. Further research should be done across a variety of riparian systems to determine both indicator species and reference values for the physical and environmental attributes that could be utilized for the assessment of riparian capability. Title: Woody riparian species patterns along northeast Oregon mountainous streams and the relationship to riparian capability Author: Yancey, Jennifer M. Woody riparian vegetation is an essential component of riparian ecosystems, responsible in part for the maintenance of functional ecological processes. The plant community composition and distribution provide an indication of the underlying mosaic of environmental attributes and processes. Restoration and management of riparian communities have been hindered by the lack of measurable criteria for the assessment of a riparian systems modified by human imposed infrastructures. The woody vegetation community offered a quantifiable indicator of the underlying mosaic of environmental, physical, and hydrological attributes, while allowing the investigation of the concept of riparian potential versus riparian capability. The examination of riparian condition was measured through the determination of species-environmental relationships along three mountainous channels in northeast Oregon. The physical and environmental attributes of channel morphology, hydrology, understory community composition, surface particle characteristics, and microclimate variables were quantified and analyzed in relation to the woody vegetation composition and distribution across the three separate streams and within flood-frequency elevation zones. The second component of the study evaluated and described methods for quantifying the concept of riparian capability, based on the measured species-environmental relationships and channel morphology. The evaluation of condition was measured against the reference baseline of Rosgen hierarchical classification and regional hydraulic geometry curves. Multivariate analyses indicated that vegetation transects grouped by stream and vegetation belt transects weakly grouped by flood zone, based on the species composition quantified within the vegetation transects and flood zones. Secondly, channel geometry, canopy cover, air temperature, channel particle size, understory composition attributes, and flood zone distance were found to be overall gradients, which described the variation in species composition across the three streams in northeast Oregon. Direct individual species-environmental relationship conclusions were weak due to the close clustering of species and multiple physical and environmental gradients. Riparian condition at the Grande Ronde River and North Fork Catherine Creek was determined to be functioning at riparian capability. Channel geometry measurements at the two stream reaches aligned with Rosgen stream type criteria and regional hydrologic curves, while species composition represented characteristics of potential natural communities. Meadow Creek was concluded to have departed from the highest attainable condition, thus riparian condition was less than capability. The results suggested that woody riparian vegetation response was a function the physical sttributes: channel morphological widths, bankfull, floodprone, 25-year flood width, valley width, channel sinuosity, and channel slope. Environmental attributes, floodplain canopy cover, air temperature, and understory composition, were further factors that influenced the woody riparian vegetation community variation. The results also suggested species richness and diversity were associated with specific physical and environmental attributes. Finally, the results provided the determination of riparian capability along montane streams in northeast Oregon and criteria acceptable for the determination of riparian capability. These criteria included the physical channel measurements assessed against Rosgen hierarchiecal classification and regional channel geometry curves; and woody vegetation presence and distribution assessed against potential natural community plant associations. Further research should be done across a variety of riparian systems to determine both indicator species and reference values for the physical and environmental attributes that could be utilized for the assessment of riparian capability. Close

• 63. [Article] Tradeoffs associated with managing forested landscapes for multiple-uses

  This study focuses on the tradeoffs that exist for managing forested landscapes for biodiversity and timber production. Tradeoff evaluation is important to natural resource managers so they can understand ...

  Citation × Citation Citation Abstract Copy Title: Tradeoffs associated with managing forested landscapes for multiple-uses Author: Lichtenstein, Mark E. This study focuses on the tradeoffs that exist for managing forested landscapes for biodiversity and timber production. Tradeoff evaluation is important to natural resource managers so they can understand the benefits and costs of alternative management prescriptions. The study examines three watersheds in the Oregon Coast Range and 166 terrestrial vertebrate species to determine the productive capacity of the site in terms of biodiversity and timber revenue. Two points are identified that maximize biodiversity and maximize timber revenue that serve as corner solutions for the production possibilities frontier for biodiversity and timber revenue. The frontier identifies all combinations of outputs that are equal in productive efficiency and the slope of the frontier identifies the marginal cost of biodiversity in terms of foregone timber revenue. A special case is then examined that reenacts the proposed management intentions of each ownership group in the study area. The special case model is used to examine the level of efficiency that exists with respect to the productive possibilities frontier. The results of the study indicate that there is a high level of inefficiency in the proposed management intentions of the various ownership groups. Higher levels of revenues can be achieved at the same level of biodiversity. Conversely more biodiversity can be produced at the same level of revenue. Marginal cost analysis also showed that biodiversity comes at an increasingly high cost at the extreme end of the productive capability of the study area. Results also indicate the species that are most affected by management activities are those that require large home ranges (> 200 acres) and species that are the most taxonomically unique. Title: Tradeoffs associated with managing forested landscapes for multiple-uses Author: Lichtenstein, Mark E. This study focuses on the tradeoffs that exist for managing forested landscapes for biodiversity and timber production. Tradeoff evaluation is important to natural resource managers so they can understand the benefits and costs of alternative management prescriptions. The study examines three watersheds in the Oregon Coast Range and 166 terrestrial vertebrate species to determine the productive capacity of the site in terms of biodiversity and timber revenue. Two points are identified that maximize biodiversity and maximize timber revenue that serve as corner solutions for the production possibilities frontier for biodiversity and timber revenue. The frontier identifies all combinations of outputs that are equal in productive efficiency and the slope of the frontier identifies the marginal cost of biodiversity in terms of foregone timber revenue. A special case is then examined that reenacts the proposed management intentions of each ownership group in the study area. The special case model is used to examine the level of efficiency that exists with respect to the productive possibilities frontier. The results of the study indicate that there is a high level of inefficiency in the proposed management intentions of the various ownership groups. Higher levels of revenues can be achieved at the same level of biodiversity. Conversely more biodiversity can be produced at the same level of revenue. Marginal cost analysis also showed that biodiversity comes at an increasingly high cost at the extreme end of the productive capability of the study area. Results also indicate the species that are most affected by management activities are those that require large home ranges (> 200 acres) and species that are the most taxonomically unique. Close

• 64. [Article] Hydrologic and vegetation responses associated with restoration of wetlands in the Willamette Valley, Oregon

  I examined hydrological and plant community changes associated with the implementation of a restoration management plan in two riparian meadows located within an agricultural landscape of the central Willamette ...

  Citation × Citation Citation Abstract Copy Title: Hydrologic and vegetation responses associated with restoration of wetlands in the Willamette Valley, Oregon Author: Coleman, Gregory A. I examined hydrological and plant community changes associated with the implementation of a restoration management plan in two riparian meadows located within an agricultural landscape of the central Willamette Valley, Oregon. I established exclosure fencing (a form of passive restoration) in one agricultural field and established fencing and plugged a drainage ditch (active restoration) in a separate agricultural field. Permanent transects 15 m in length were established within two plant communities associated with hydrological regimes within these restored agricultural fields. Plant communities were classified as wetland meadow (inundated for more than 4 weeks/year) and mesic meadow (saturated within the upper 30 cm but not inundated) for at least 4 weeks/year. Four transects were randomly established within the wet meadow community and 6 transects were randomly situated within the mesic meadow community. Two shallow subsurface piezometers were installed to a depth of 1 m at 5 m and 10 m along each of these 15 m transects. Additionally, two shallow sub-surface piezometers were established at the outer perimeter of the agriculturally excluded fields. Shallow sub-surface and surface water table levels were measured at each piezometer after wetlands were inundated and continued until water table dropped below the piezometers (Dec. - June) for one pre-treatment and two post treatment years. The actively restored wet and mesic meadows demonstrated increased water table elevation and a decrease in water table fluctuation during both post treatment years. Increases in water table elevation were greatest in areas closest to active restoration but were significant up to 102 m. from restoration. Results indicate that filling drainage ditches induce hydrologic effects at great distances across floodplain soils. Plant community composition (species response) was quantified in both restored sites as well as the adjacent agriculturally managed (untreated) sites one year before treatment and two post-treatment years. I sampled two plant community types: wet meadow and mesic meadow. I calculated species richness and the relative abundance of wetland indicator species, nuisance weeds, and native plants. Nuisance weeds increased and native plant abundance decreased in agriculturally managed mesic meadows. Wetland plant species abundance tended to increase in agricultural sites with light grazing, and decreased in areas that were plowed and re-seeded. Native plants increased and nuisance weeds decreased in the actively restored mesic meadow. The passively restored mesic meadow exhibited no change in native plant abundance and decreases in all other categories. In the actively restored wetland there were increases in plant species richness and nuisance weed abundance with a decrease in native plant abundance. Agriculturally excluded wetlands dominated by Reed canary grass (Phalaris arundinacea) exhibited no changes for the entire study period. Results suggest that for the first few years following agricultural exclusion, nuisance weed species do not increase, but active restoration may result in increases (due to disturbance). Additionally, results indicate restored agricultural landscapes dominated by introduced grasses demonstrate minimal short-term plant community change unless initiated by intense land management practices (e g., plowing, re-seeding, or removal of dominant plant communities). Based upon results of this study, I conclude that restoration plans should repair damaged hydrological features before planting riparian plant species. Following this chronological sequence will minimize the potential destruction of planted communities by future shifts in water table elevation caused by hydrologic restoration. Furthermore, any active restoration that initiates a direct or indirect removal of the dominant plant community should be accompanied by aggressive plantings of desirable plant species and prolonged site maintenance. Title: Hydrologic and vegetation responses associated with restoration of wetlands in the Willamette Valley, Oregon Author: Coleman, Gregory A. I examined hydrological and plant community changes associated with the implementation of a restoration management plan in two riparian meadows located within an agricultural landscape of the central Willamette Valley, Oregon. I established exclosure fencing (a form of passive restoration) in one agricultural field and established fencing and plugged a drainage ditch (active restoration) in a separate agricultural field. Permanent transects 15 m in length were established within two plant communities associated with hydrological regimes within these restored agricultural fields. Plant communities were classified as wetland meadow (inundated for more than 4 weeks/year) and mesic meadow (saturated within the upper 30 cm but not inundated) for at least 4 weeks/year. Four transects were randomly established within the wet meadow community and 6 transects were randomly situated within the mesic meadow community. Two shallow subsurface piezometers were installed to a depth of 1 m at 5 m and 10 m along each of these 15 m transects. Additionally, two shallow sub-surface piezometers were established at the outer perimeter of the agriculturally excluded fields. Shallow sub-surface and surface water table levels were measured at each piezometer after wetlands were inundated and continued until water table dropped below the piezometers (Dec. - June) for one pre-treatment and two post treatment years. The actively restored wet and mesic meadows demonstrated increased water table elevation and a decrease in water table fluctuation during both post treatment years. Increases in water table elevation were greatest in areas closest to active restoration but were significant up to 102 m. from restoration. Results indicate that filling drainage ditches induce hydrologic effects at great distances across floodplain soils. Plant community composition (species response) was quantified in both restored sites as well as the adjacent agriculturally managed (untreated) sites one year before treatment and two post-treatment years. I sampled two plant community types: wet meadow and mesic meadow. I calculated species richness and the relative abundance of wetland indicator species, nuisance weeds, and native plants. Nuisance weeds increased and native plant abundance decreased in agriculturally managed mesic meadows. Wetland plant species abundance tended to increase in agricultural sites with light grazing, and decreased in areas that were plowed and re-seeded. Native plants increased and nuisance weeds decreased in the actively restored mesic meadow. The passively restored mesic meadow exhibited no change in native plant abundance and decreases in all other categories. In the actively restored wetland there were increases in plant species richness and nuisance weed abundance with a decrease in native plant abundance. Agriculturally excluded wetlands dominated by Reed canary grass (Phalaris arundinacea) exhibited no changes for the entire study period. Results suggest that for the first few years following agricultural exclusion, nuisance weed species do not increase, but active restoration may result in increases (due to disturbance). Additionally, results indicate restored agricultural landscapes dominated by introduced grasses demonstrate minimal short-term plant community change unless initiated by intense land management practices (e g., plowing, re-seeding, or removal of dominant plant communities). Based upon results of this study, I conclude that restoration plans should repair damaged hydrological features before planting riparian plant species. Following this chronological sequence will minimize the potential destruction of planted communities by future shifts in water table elevation caused by hydrologic restoration. Furthermore, any active restoration that initiates a direct or indirect removal of the dominant plant community should be accompanied by aggressive plantings of desirable plant species and prolonged site maintenance. Close

• 65. [Article] Ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae)

  A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence ...

  Citation × Citation Citation Abstract Copy Title: Ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae) Author: Campanella, Donald Michael A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence the ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae). Interactions between natural enemy species may modify their net effect on host plants, but little research has been done to examine how plant resistance influences species interactions in biological weed control. First, we performed common garden experiments with clonal accessions of C. juncea to compare a rust-susceptible weed biotype with a rust-resistant biotype, both of which are invasive in western North America. Inoculations with two biological control organisms, a rust fungus pathogen (Puccinia chondrillina) and an eriophyid gall mite (Eriophyes chondrillae), were applied separately and in combination to test if plant performance is modified by antagonistic or facilitative species interactions. We found no significant rust x mite interaction effects for several plant traits (shoot length, shoot dry biomass, fecundity, rosette growth, and rosette senescence), and therefore the two natural enemies appear to have independent and complementary effects on plant performance. However, rust inoculation reduced the total dry biomass of mite galls in the rust-susceptible biotype by indirect competition due to decreased growth of diseased shoots, but not in the rust-resistant biotype. Our results indicate that rust disease may have the potential to modify mite gall epidemiology and relative plant performance in mixed populations of resistant and susceptible C. juncea biotypes. In the second part of the study, a monitoring survey of C. juncea was conducted in southwest Oregon during 2006 to investigate natural associations in the distribution of damage caused by P. chondrillina, E. chondrillae, and the cecidomyiid gall midge Cystiphora schmidti. Mite galling was the most aggregated type of damage both within and among field sites. Analysis of an allometric relationship of shoot growth (biomass versus stem area) indicates that rust disease reduced C. juncea growth but only at high stand density, and in general rust disease was the most randomly distributed type of damage within sites. There was no evidence from the field survey to support a species interaction between the gall mite and the rust pathogen, but negative associations were detected between midge galling and the damage caused by both of the other natural enemies, which may indicate species interaction via rust and/or mite interference with C. schmidti oviposition. However, this potential antagonism was found only at high stand density with relatively high levels of damage caused by each natural enemy, and so the overall impact of biological control probably is not strongly diminished by enemy interference. The third part of the study was a mathematical model of inheritance and genetic equilibrium in meiotic diplospory, which is an unusual mechanism of gametophytic apomixis occurring in invasive populations of C. juncea and also in triploid dandelions (Taraxacum officinale). Crossing-over during prophase I of meiotic diplospory has the potential to generate genotypic diversity in apomictic lineages because it involves homologous recombination without fertilization ("subsexual reproduction"). I developed a stage-structured matrix model of inheritance in subsexual reproduction using a wide range of probabilities for recombination and mutation to assess the range of equilibrium conditions under which genotypic diversity is stable in obligately apomictic lines. The analysis supports predictions of genotypic diversity when rates of crossing-over and mutation are not highly imbalanced. Therefore subsexual reproduction remains mathematically plausible as a contributing factor to the quantitative variation in disease resistance and ecological traits of invasive C. juncea found in this study and others. Title: Ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae) Author: Campanella, Donald Michael A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence the ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae). Interactions between natural enemy species may modify their net effect on host plants, but little research has been done to examine how plant resistance influences species interactions in biological weed control. First, we performed common garden experiments with clonal accessions of C. juncea to compare a rust-susceptible weed biotype with a rust-resistant biotype, both of which are invasive in western North America. Inoculations with two biological control organisms, a rust fungus pathogen (Puccinia chondrillina) and an eriophyid gall mite (Eriophyes chondrillae), were applied separately and in combination to test if plant performance is modified by antagonistic or facilitative species interactions. We found no significant rust x mite interaction effects for several plant traits (shoot length, shoot dry biomass, fecundity, rosette growth, and rosette senescence), and therefore the two natural enemies appear to have independent and complementary effects on plant performance. However, rust inoculation reduced the total dry biomass of mite galls in the rust-susceptible biotype by indirect competition due to decreased growth of diseased shoots, but not in the rust-resistant biotype. Our results indicate that rust disease may have the potential to modify mite gall epidemiology and relative plant performance in mixed populations of resistant and susceptible C. juncea biotypes. In the second part of the study, a monitoring survey of C. juncea was conducted in southwest Oregon during 2006 to investigate natural associations in the distribution of damage caused by P. chondrillina, E. chondrillae, and the cecidomyiid gall midge Cystiphora schmidti. Mite galling was the most aggregated type of damage both within and among field sites. Analysis of an allometric relationship of shoot growth (biomass versus stem area) indicates that rust disease reduced C. juncea growth but only at high stand density, and in general rust disease was the most randomly distributed type of damage within sites. There was no evidence from the field survey to support a species interaction between the gall mite and the rust pathogen, but negative associations were detected between midge galling and the damage caused by both of the other natural enemies, which may indicate species interaction via rust and/or mite interference with C. schmidti oviposition. However, this potential antagonism was found only at high stand density with relatively high levels of damage caused by each natural enemy, and so the overall impact of biological control probably is not strongly diminished by enemy interference. The third part of the study was a mathematical model of inheritance and genetic equilibrium in meiotic diplospory, which is an unusual mechanism of gametophytic apomixis occurring in invasive populations of C. juncea and also in triploid dandelions (Taraxacum officinale). Crossing-over during prophase I of meiotic diplospory has the potential to generate genotypic diversity in apomictic lineages because it involves homologous recombination without fertilization ("subsexual reproduction"). I developed a stage-structured matrix model of inheritance in subsexual reproduction using a wide range of probabilities for recombination and mutation to assess the range of equilibrium conditions under which genotypic diversity is stable in obligately apomictic lines. The analysis supports predictions of genotypic diversity when rates of crossing-over and mutation are not highly imbalanced. Therefore subsexual reproduction remains mathematically plausible as a contributing factor to the quantitative variation in disease resistance and ecological traits of invasive C. juncea found in this study and others. Close

• 66. [Article] Trophic dynamics of marine nekton and zooplankton in the Northern California Current ecosystem

  The Northern California Current (NCC) ecosystem exhibits extreme seasonal, interannual and interdecadal shifts in the abiotic environment and shifts in primary and higher production. This variability is ...

  Citation × Citation Citation Abstract Copy Title: Trophic dynamics of marine nekton and zooplankton in the Northern California Current ecosystem Author: Miller, Todd William The Northern California Current (NCC) ecosystem exhibits extreme seasonal, interannual and interdecadal shifts in the abiotic environment and shifts in primary and higher production. This variability is also apparent in the spatial structure of the ecosystem with nearshore-shelf waters (<150 m isobath) being highly productive and having a different community structure relative to more offshore-slope (>150 m) waters. Very little is known of the trophic relationships between primary consumers and higher trophic levels within this system, and the potential influence of spatial gradients in productivity and community composition on trophic structure. This dissertation research covers several important aspects of trophic dynamics within the NCC ecosystem through the use of conventional dietary analysis and stable isotope analysis of multiple trophic levels. From June and August 2000 and 2002 cruises off the shelf-slope ecosystem from Northern California to central Oregon, I collected and analyzed the diets from 25 species of pelagic nekton (Chapter 2). Trophic groups were formed from agglomerative hierarchical cluster analysis of prey contribution to nekton diet, with cluster groups described by indicator species analysis. Seasonal, interannual and interdecadal comparisons in diet were examined for some nekton species. Results from general description of diets and cluster analysis showed clustering based primarily on prey of copepods, euphausiids, decapod larvae and larval-juvenile fishes, representing lower (copepods), middle (euphausiids and decapod larvae) and upper (larval-juvenile fishes) trophic groups, but that many species exhibited omnivory by feeding on prey several levels down the food web. Results from carbon and nitrogen stable isotope analysis (Chapter 3) support the general trophic structure observed through dietary analysis; that the copepod-euphausiid-larval/juvenile fish structure in the diets were generally observed in relative trophic position using δ15N. Carbon stable isotopes displayed signatures more indicative of onshore-offshore distribution of species (Chapter 4) with nearshore species of nekton and zooplankton being enriched in 13C relative to offshore. This provided an effective trophically-based delineation of the NCC pelagic food web. Although stable isotopes are effective tools for measuring relative trophic position and source production, the duration of time that stable isotopes are a measure of past trophic hsitory is not well known. To examine this, I conducted a laboratory-controlled experiment to examine the tissue-specific response of isotope δ15N to changes in isotopic signature of diet in an adult marine fish (Pacific herring, Clupea pallasi)(Chapter 5). To test which animal tissue was the most accurate measure of isotope shift I examined multiple tissues (eye, heart, liver, blood, and white muscle) and the importance of growth and metabolism in this shift. This study showed that (i) isotopic response of individual tissues following an isotopic shift in diet varied in both rate of change and fractionation level, (ii) most of this isotopic shift is due to growth, and (iii) white muscle and liver tissue appeared the most responsive to isotopic shift in diet, reaching isotopic equilibrium with diet in a matter of months (not years). The culmination of this dissertation in the context of trophic controls on the NCC ecosystem, and how they are different from other EBC systems are discussed in Chapter 6. Title: Trophic dynamics of marine nekton and zooplankton in the Northern California Current ecosystem Author: Miller, Todd William The Northern California Current (NCC) ecosystem exhibits extreme seasonal, interannual and interdecadal shifts in the abiotic environment and shifts in primary and higher production. This variability is also apparent in the spatial structure of the ecosystem with nearshore-shelf waters (<150 m isobath) being highly productive and having a different community structure relative to more offshore-slope (>150 m) waters. Very little is known of the trophic relationships between primary consumers and higher trophic levels within this system, and the potential influence of spatial gradients in productivity and community composition on trophic structure. This dissertation research covers several important aspects of trophic dynamics within the NCC ecosystem through the use of conventional dietary analysis and stable isotope analysis of multiple trophic levels. From June and August 2000 and 2002 cruises off the shelf-slope ecosystem from Northern California to central Oregon, I collected and analyzed the diets from 25 species of pelagic nekton (Chapter 2). Trophic groups were formed from agglomerative hierarchical cluster analysis of prey contribution to nekton diet, with cluster groups described by indicator species analysis. Seasonal, interannual and interdecadal comparisons in diet were examined for some nekton species. Results from general description of diets and cluster analysis showed clustering based primarily on prey of copepods, euphausiids, decapod larvae and larval-juvenile fishes, representing lower (copepods), middle (euphausiids and decapod larvae) and upper (larval-juvenile fishes) trophic groups, but that many species exhibited omnivory by feeding on prey several levels down the food web. Results from carbon and nitrogen stable isotope analysis (Chapter 3) support the general trophic structure observed through dietary analysis; that the copepod-euphausiid-larval/juvenile fish structure in the diets were generally observed in relative trophic position using δ15N. Carbon stable isotopes displayed signatures more indicative of onshore-offshore distribution of species (Chapter 4) with nearshore species of nekton and zooplankton being enriched in 13C relative to offshore. This provided an effective trophically-based delineation of the NCC pelagic food web. Although stable isotopes are effective tools for measuring relative trophic position and source production, the duration of time that stable isotopes are a measure of past trophic hsitory is not well known. To examine this, I conducted a laboratory-controlled experiment to examine the tissue-specific response of isotope δ15N to changes in isotopic signature of diet in an adult marine fish (Pacific herring, Clupea pallasi)(Chapter 5). To test which animal tissue was the most accurate measure of isotope shift I examined multiple tissues (eye, heart, liver, blood, and white muscle) and the importance of growth and metabolism in this shift. This study showed that (i) isotopic response of individual tissues following an isotopic shift in diet varied in both rate of change and fractionation level, (ii) most of this isotopic shift is due to growth, and (iii) white muscle and liver tissue appeared the most responsive to isotopic shift in diet, reaching isotopic equilibrium with diet in a matter of months (not years). The culmination of this dissertation in the context of trophic controls on the NCC ecosystem, and how they are different from other EBC systems are discussed in Chapter 6. Close

• 67. [Article] Reconnaissance botany of alpine ecosystems on Prince of Wales Island, southeast Alaska

  A study of the Prince of Wales Island alpine areas was undertaken to determine what species occur in the region and to describe plant communities making up the alpine vegetation. For one month in 1972, ...

  Citation × Citation Citation Abstract Copy Title: Reconnaissance botany of alpine ecosystems on Prince of Wales Island, southeast Alaska Author: Jaques, Dennis Randall A study of the Prince of Wales Island alpine areas was undertaken to determine what species occur in the region and to describe plant communities making up the alpine vegetation. For one month in 1972, specimens were collected and 78 micro-plots were analyzed for cover, frequency and constancy data. Three basic habitat types were discovered, with different associations being recognized on calcareous and noncalcareous substrates. Alpine vegetation patterns are formed in a physiographically unstable area. However, where conditions remain favorable for a long enough period of time, a climatic climax of Empetrum-heath vegetation develops. Elsewhere topographic climax vegetation exists. The region is thought to have maintained a flora of significant proportions at least since early post-Pleistocene time. The presence of many disjunct species indicates that floral elements may have survived Pleistocene ice advances in various refugial sites. The west coast of Prince of Wales Island appears to have served as a small migration center following Pleistocene ice recession. Title: Reconnaissance botany of alpine ecosystems on Prince of Wales Island, southeast Alaska Author: Jaques, Dennis Randall A study of the Prince of Wales Island alpine areas was undertaken to determine what species occur in the region and to describe plant communities making up the alpine vegetation. For one month in 1972, specimens were collected and 78 micro-plots were analyzed for cover, frequency and constancy data. Three basic habitat types were discovered, with different associations being recognized on calcareous and noncalcareous substrates. Alpine vegetation patterns are formed in a physiographically unstable area. However, where conditions remain favorable for a long enough period of time, a climatic climax of Empetrum-heath vegetation develops. Elsewhere topographic climax vegetation exists. The region is thought to have maintained a flora of significant proportions at least since early post-Pleistocene time. The presence of many disjunct species indicates that floral elements may have survived Pleistocene ice advances in various refugial sites. The west coast of Prince of Wales Island appears to have served as a small migration center following Pleistocene ice recession. Close

• 68. [Article] El Nino related variations in nutrient and chlorophyll distributions off Oregon

  The Oregon continental shelf waters are typically characterized by four to five major upwelling events that occur between May and October. The upwelled water is rich in nutrients, which fuels an increase ...

  Citation × Citation Citation Abstract Copy Title: El Nino related variations in nutrient and chlorophyll distributions off Oregon Author: Corwith, Holly L. The Oregon continental shelf waters are typically characterized by four to five major upwelling events that occur between May and October. The upwelled water is rich in nutrients, which fuels an increase in phytoplankton biomass. The onset of El Nino, however, can disrupt the normal physical processes along the Oregon coastline by decreasing upwelling, thereby potentially changing the distribution of nutrients and chlorophyll in this region. As part of the Eastern North Pacific GLOBEC program, we have examined the direct effect of El Nino on nutrient and chlorophyll distributions along the Oregon coast. We sampled chlorophyll and nutrients (phosphate, silicate, nitrate, nitrite, and ammonium) from September 1997 through July 1999 along 4 lines from 40°52.0' to 44°39.1'. Results showed that the shelf was nitrate limited, and chlorophyll concentrations were significantly lower off Newport during the El Nino summer. The percentage of large sized cells (> 10 gm) was decreased to 23% of the total population, as compared to 92% found during the more typical upwelling conditions in August. 1998, which indicates a species composition change occurred during the El Nino period. The slope and offshore waters were less affected by the El Nino conditions during the upwelling season. Title: El Nino related variations in nutrient and chlorophyll distributions off Oregon Author: Corwith, Holly L. The Oregon continental shelf waters are typically characterized by four to five major upwelling events that occur between May and October. The upwelled water is rich in nutrients, which fuels an increase in phytoplankton biomass. The onset of El Nino, however, can disrupt the normal physical processes along the Oregon coastline by decreasing upwelling, thereby potentially changing the distribution of nutrients and chlorophyll in this region. As part of the Eastern North Pacific GLOBEC program, we have examined the direct effect of El Nino on nutrient and chlorophyll distributions along the Oregon coast. We sampled chlorophyll and nutrients (phosphate, silicate, nitrate, nitrite, and ammonium) from September 1997 through July 1999 along 4 lines from 40°52.0' to 44°39.1'. Results showed that the shelf was nitrate limited, and chlorophyll concentrations were significantly lower off Newport during the El Nino summer. The percentage of large sized cells (> 10 gm) was decreased to 23% of the total population, as compared to 92% found during the more typical upwelling conditions in August. 1998, which indicates a species composition change occurred during the El Nino period. The slope and offshore waters were less affected by the El Nino conditions during the upwelling season. Close

• 69. [Article] Lidar-derived canopy architecture predicts brown creeper occupancy of two western coniferous forests

  This is the publisher’s final pdf. The published article is copyrighted by The Cooper Ornithological Society and can be found at: http://www.cooper.org/.

  Citation × Citation Citation Abstract Copy Title: Lidar-derived canopy architecture predicts brown creeper occupancy of two western coniferous forests Author: Vogeler, Jody C., Vierling, Lee A., Vierling, Kerri T., Hudak, Andrew T. This is the publisher’s final pdf. The published article is copyrighted by The Cooper Ornithological Society and can be found at: http://www.cooper.org/. Title: Lidar-derived canopy architecture predicts brown creeper occupancy of two western coniferous forests Author: Vogeler, Jody C., Vierling, Lee A., Vierling, Kerri T., Hudak, Andrew T. This is the publisher’s final pdf. The published article is copyrighted by The Cooper Ornithological Society and can be found at: http://www.cooper.org/. Close

• 70. [Article] Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem Author: Reese, Douglas C., Brodeur, Richard D. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-marine-systems/. Title: Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem Author: Reese, Douglas C., Brodeur, Richard D. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-marine-systems/. Close