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• 31. [Article] Species composition and community structure of pelagic nekton off Oregon and Washington under variable oceanographic conditions

  The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/

  Citation × Citation Citation Abstract Copy Title: Species composition and community structure of pelagic nekton off Oregon and Washington under variable oceanographic conditions Author: Fisher, Joseph P., Emmett, Robert L., Morgan, Cheryl A., Casillas, Ed, Brodeur, Richard D. The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/ Title: Species composition and community structure of pelagic nekton off Oregon and Washington under variable oceanographic conditions Author: Fisher, Joseph P., Emmett, Robert L., Morgan, Cheryl A., Casillas, Ed, Brodeur, Richard D. The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/ Close

• 32. [Article] Probabilistic modeling of understory vegetation species in a northeastern Oregon industrial forest

  Managing forest ecosystems for sustainable, multiple use requires forest resource managers to understand how species composition and distribution vary across environmental gradients and respond to landscape ...

  Citation × Citation Citation Abstract Copy Title: Probabilistic modeling of understory vegetation species in a northeastern Oregon industrial forest Author: Yost, Andrew Charles Managing forest ecosystems for sustainable, multiple use requires forest resource managers to understand how species composition and distribution vary across environmental gradients and respond to landscape scale disturbance. A number of statistical modeling tools are available to construct predictive models and maps from response data, a set of predictor variables, and a predefined statistical distribution. Non-Parametric Multiplicative Regression (NPMR) is a probability modeling system that finds the best multiplicative set of predictor variables. The best set maximizes the Bayes Factor value which is a ratio based on modeled estimates and a species' average frequency of occurrence. This study demonstrates predictive vegetation modeling and mapping using NPMR and species presence/absence data collected from 610 plots located across an industrial managed forest landscape in Northeast Oregon. Plots were stratified with a random sampling design. Four modeling approaches were taken to compare the predictive power of spatial coordinates in combination with a set of topographically-derived and stand structural predictor variables. Spatial coordinates were often the most powerful predictors and the modeling approach with physiographic and stand structural variables together was frequently the most improved relative to the average frequency of occurrence. Comparisons between Logistic Regression (LR) and NPMR models were conducted for the species Clintonia unflora (CLUN) and Pinus ponderosa (PIPO). NPMR performed better for CLUN when the best predictor variables selected by NPMR were used to construct a LR model. For PIPO, the performance of NPMR was comparable to LR when the set of predictor variables used to build the LR model was based on whether the response in probability to each variable was monotonic. Species-level GIS probability maps were produced with the application of the physiographic models and a corresponding set of GIS raster files. GIS overlays of indicator species maps were used to construct plant association group (PAG) maps. Intersections of PAG layers resulted in quantitative mapping of intergrade between types. PAG layers were often significant predictor variables in probability models for 70 understory and five conifer species produced with Logistic Regression (LR) using a forward step-wise process. Potential applications of both NPMR and LR models with the Forest Vegetation Simulator are discussed. Title: Probabilistic modeling of understory vegetation species in a northeastern Oregon industrial forest Author: Yost, Andrew Charles Managing forest ecosystems for sustainable, multiple use requires forest resource managers to understand how species composition and distribution vary across environmental gradients and respond to landscape scale disturbance. A number of statistical modeling tools are available to construct predictive models and maps from response data, a set of predictor variables, and a predefined statistical distribution. Non-Parametric Multiplicative Regression (NPMR) is a probability modeling system that finds the best multiplicative set of predictor variables. The best set maximizes the Bayes Factor value which is a ratio based on modeled estimates and a species' average frequency of occurrence. This study demonstrates predictive vegetation modeling and mapping using NPMR and species presence/absence data collected from 610 plots located across an industrial managed forest landscape in Northeast Oregon. Plots were stratified with a random sampling design. Four modeling approaches were taken to compare the predictive power of spatial coordinates in combination with a set of topographically-derived and stand structural predictor variables. Spatial coordinates were often the most powerful predictors and the modeling approach with physiographic and stand structural variables together was frequently the most improved relative to the average frequency of occurrence. Comparisons between Logistic Regression (LR) and NPMR models were conducted for the species Clintonia unflora (CLUN) and Pinus ponderosa (PIPO). NPMR performed better for CLUN when the best predictor variables selected by NPMR were used to construct a LR model. For PIPO, the performance of NPMR was comparable to LR when the set of predictor variables used to build the LR model was based on whether the response in probability to each variable was monotonic. Species-level GIS probability maps were produced with the application of the physiographic models and a corresponding set of GIS raster files. GIS overlays of indicator species maps were used to construct plant association group (PAG) maps. Intersections of PAG layers resulted in quantitative mapping of intergrade between types. PAG layers were often significant predictor variables in probability models for 70 understory and five conifer species produced with Logistic Regression (LR) using a forward step-wise process. Potential applications of both NPMR and LR models with the Forest Vegetation Simulator are discussed. Close

• 33. [Article] Ecological survey and interpretation of the Willamette Floodplain Research Natural Area, W.L. Finley National Wildlife Refuge, Oregon

  The purpose of this study was to: (1) evaluate land use and vegetation history of the Willamette Floodplain Research Natural Area; (2) characterize present day vegetation; (3) evaluate the relation of ...

  Citation × Citation Citation Abstract Copy Title: Ecological survey and interpretation of the Willamette Floodplain Research Natural Area, W.L. Finley National Wildlife Refuge, Oregon Author: Streatfeild, Rosemary Welch The purpose of this study was to: (1) evaluate land use and vegetation history of the Willamette Floodplain Research Natural Area; (2) characterize present day vegetation; (3) evaluate the relation of vegetation to environment, and (4) establish a baseline dataset for future trend analysis in order that response of different plant species to fire frequencies may be assessed. I used historical records, aerial photographs, interviews, and literature to ascertain land use and vegetation history. I assumed that the RNA had been maintained as prairie by periodic aboriginal burning. Fire ignited by settlers continued as a management tool into the late 19th century. Grazing was a major disturbance in the late 19th and early 20th centuries, and plowing or some other soil disturbance on the raised elongated mounds may have occurred. With removal of livestock grazing in the early 1960s and only a sporadic burning program, shrub cover increased markedly over the past several decades. I surveyed vegetation in the summer of 1991 in 36 random permanent plots. 1 classified species cover with two-way indicator species analysis, identifying two major communities. One is dominated by tall dense Rosa eg'lanteria, Hypericum perforatum, and many alien weedy species located on slightly elevated mounds, and the other is dominated by shorter but also dense Rosa eglanteria, Deschampsia cespitosa, and many species with wetland affinity on intermounds. Monotypic patches of Spiraea douglasii also occur on intermounds. Species composition strongly correlates with raicrotopography related to an indirect soil moisture index based on wetland status of individual species. Composition correlates less strongly with year since last burn. I confirmed vegetation-environment relations by null hypothesis analysis, tested by multi-response permutation procedure. Vegetation significantly differs on mounds vs. intermounds and vegetation significantly reflects burning history. I ordinated floristic data by non-metric scaling. I also tallied nested frequency data as a baseline for future trend analysis in order to assess change in vegetation in response to fire frequency. Frequency change of Rosa eglanteria will best be detected by change in a 0.01 m2 plot size, Holcus lanatus by a 0.10 m2 plot, and remaining species by a 1.00 m2 plot. Title: Ecological survey and interpretation of the Willamette Floodplain Research Natural Area, W.L. Finley National Wildlife Refuge, Oregon Author: Streatfeild, Rosemary Welch The purpose of this study was to: (1) evaluate land use and vegetation history of the Willamette Floodplain Research Natural Area; (2) characterize present day vegetation; (3) evaluate the relation of vegetation to environment, and (4) establish a baseline dataset for future trend analysis in order that response of different plant species to fire frequencies may be assessed. I used historical records, aerial photographs, interviews, and literature to ascertain land use and vegetation history. I assumed that the RNA had been maintained as prairie by periodic aboriginal burning. Fire ignited by settlers continued as a management tool into the late 19th century. Grazing was a major disturbance in the late 19th and early 20th centuries, and plowing or some other soil disturbance on the raised elongated mounds may have occurred. With removal of livestock grazing in the early 1960s and only a sporadic burning program, shrub cover increased markedly over the past several decades. I surveyed vegetation in the summer of 1991 in 36 random permanent plots. 1 classified species cover with two-way indicator species analysis, identifying two major communities. One is dominated by tall dense Rosa eg'lanteria, Hypericum perforatum, and many alien weedy species located on slightly elevated mounds, and the other is dominated by shorter but also dense Rosa eglanteria, Deschampsia cespitosa, and many species with wetland affinity on intermounds. Monotypic patches of Spiraea douglasii also occur on intermounds. Species composition strongly correlates with raicrotopography related to an indirect soil moisture index based on wetland status of individual species. Composition correlates less strongly with year since last burn. I confirmed vegetation-environment relations by null hypothesis analysis, tested by multi-response permutation procedure. Vegetation significantly differs on mounds vs. intermounds and vegetation significantly reflects burning history. I ordinated floristic data by non-metric scaling. I also tallied nested frequency data as a baseline for future trend analysis in order to assess change in vegetation in response to fire frequency. Frequency change of Rosa eglanteria will best be detected by change in a 0.01 m2 plot size, Holcus lanatus by a 0.10 m2 plot, and remaining species by a 1.00 m2 plot. Close

• 34. [Article] Zooplankton of the Galapagos Islands

  The marine climate of the Galapagos is spatially and seasonally heterogeneous. A taxonomically comprehensive study of Galapagos zooplankton has never been done. This study is an initial effort to establish ...

  Citation × Citation Citation Abstract Copy Title: Zooplankton of the Galapagos Islands Author: Figueroa, Diego The marine climate of the Galapagos is spatially and seasonally heterogeneous. A taxonomically comprehensive study of Galapagos zooplankton has never been done. This study is an initial effort to establish the distribution and community structure of zooplankton in the Archipelago. I collected zooplankton samples by vertical tows over the Galapagos shelf during the islands’ cold and warm seasons. Abundance was determined and copepods and euphausiids were identified to species. Hydrographic, nutrient and chlorophyll profiles were obtained for some sites. Non-metric Multidimensional Scaling (NMS) ordinations, Multi-Response Permutation Procedures (MRPP) and Indicator Species Analyses (ISA) were used to determine trends in community composition. Two marine systems were identified: 1) a nutrient-rich upwelling system with a shallow mixed layer and a diatom dominated phytoplankton community in the west and 2) a non-upwelling system with a deeper mixed layer, lower surface nutrient concentrations and a phytoplankton community dominated by small cells in the east. During the cold season three distinct zooplankton communities were observed that divide into western, central, and southeastern regions. During the warm season, the community in the west was replaced by a mix of species from the central region and abundance decreased. The diverse zooplankton community with varying geographical and seasonal affinities reflects the advective sources of surrounding waters. In addition to diverse oceanic environments, the Galapagos also have a unique set of inland pools known as anchialine habitats. I collected zooplankton from various anchialine pools in three different islands. These pools contain species of specialized cave-dwellers including undescribed species of Ridgewayia and Pseudocyclops (calanoid copepods). I describe these species and apply morphological and molecular methods to determine phylogenetic relationships and patterns of colonization. The mitochondrial gene cytochrome c oxidase subunit I (COI) and the nuclear internal transcribed spacer 1 (ITS1) were used for phylogenetic analyses. The ITS1gene successfully reconstructed phylogenies, but the COI gene was highly conserved across these two families. This gene may not be appropriate as the current standard for “bar-coding” all marine species. These anchialine copepods are a result of several independent colonization events with phylogenetic ties to extant species in the western Pacific and Caribbean. Title: Zooplankton of the Galapagos Islands Author: Figueroa, Diego The marine climate of the Galapagos is spatially and seasonally heterogeneous. A taxonomically comprehensive study of Galapagos zooplankton has never been done. This study is an initial effort to establish the distribution and community structure of zooplankton in the Archipelago. I collected zooplankton samples by vertical tows over the Galapagos shelf during the islands’ cold and warm seasons. Abundance was determined and copepods and euphausiids were identified to species. Hydrographic, nutrient and chlorophyll profiles were obtained for some sites. Non-metric Multidimensional Scaling (NMS) ordinations, Multi-Response Permutation Procedures (MRPP) and Indicator Species Analyses (ISA) were used to determine trends in community composition. Two marine systems were identified: 1) a nutrient-rich upwelling system with a shallow mixed layer and a diatom dominated phytoplankton community in the west and 2) a non-upwelling system with a deeper mixed layer, lower surface nutrient concentrations and a phytoplankton community dominated by small cells in the east. During the cold season three distinct zooplankton communities were observed that divide into western, central, and southeastern regions. During the warm season, the community in the west was replaced by a mix of species from the central region and abundance decreased. The diverse zooplankton community with varying geographical and seasonal affinities reflects the advective sources of surrounding waters. In addition to diverse oceanic environments, the Galapagos also have a unique set of inland pools known as anchialine habitats. I collected zooplankton from various anchialine pools in three different islands. These pools contain species of specialized cave-dwellers including undescribed species of Ridgewayia and Pseudocyclops (calanoid copepods). I describe these species and apply morphological and molecular methods to determine phylogenetic relationships and patterns of colonization. The mitochondrial gene cytochrome c oxidase subunit I (COI) and the nuclear internal transcribed spacer 1 (ITS1) were used for phylogenetic analyses. The ITS1gene successfully reconstructed phylogenies, but the COI gene was highly conserved across these two families. This gene may not be appropriate as the current standard for “bar-coding” all marine species. These anchialine copepods are a result of several independent colonization events with phylogenetic ties to extant species in the western Pacific and Caribbean. Close

• 35. [Article] Small mammal distribution, abundance and habitat selection in managed riparian habitats of Bear Valley, eastern Oregon

  Riparian zones are critical habitats for management because of their importance for both cattle production and wildlife, and a high potential for resource conflicts. Riparian management should address ...

  Citation × Citation Citation Abstract Copy Title: Small mammal distribution, abundance and habitat selection in managed riparian habitats of Bear Valley, eastern Oregon Author: Tomas, Walfrido Moraes Riparian zones are critical habitats for management because of their importance for both cattle production and wildlife, and a high potential for resource conflicts. Riparian management should address habitat and microhabitat features that sustain both livestock production and wildlife diversity. I conducted a study to determine how small mammal distributions and abundance differ among 3 structurally different riparian habitats in eastern Oregon. The 3 habitat types, herbaceous, discontinuous willow, and continuous willow, represent a range of habitats typical of riparian zones in central and eastern Oregon. I estimated small mammal population sizes in 9 trap grids placed in riparian zones using capture-recapture techniques. Four species of small mammals were captured during 7 trapping periods from August 1994 to September 1995. Small mammal distributions and population sizes of each species varied both within and among riparian pastures. Montane voles (Microtus montanus) were the most abundant species in all grids. Deer mice (Peromyscus maniculatus) had high population sizes in grids with low montane vole populations and moderate to high willow cover. Competition with voles appeared to occur in riparian habitats of Bear Valley, and influenced the distribution and numbers of deer mice. Western jumping mice (Zapus princeps) were captured at relatively low numbers and almost exclusively in continuous willow habitats. Vagrant shrews (Sorex vagrans) were captured on all grids, and population sizes were small. Haying negatively affected survival rates of voles. Biomass, vegetation height, and percent ground cover were the habitat variables most frequently associated with occurrence of montane voles in Bear Valley. The probability of occurrence of this species was positively correlated with these habitat variables. Deer mice probability of occurrence was positively correlated with percent ground cover, plant biomass, and soil moisture. Most deer mice captures occurred in continuous willow habitats, and the number of captures increased with willow basal cover (R²=0.7579, P<0.001). Western jumping mice occurrence was positively correlated with plant biomass and soil moisture, and negatively correlated with distance from willow and percent ground cover. Western jumping mice also were more frequently captured in willow than nonwillow vegetation associations (P=0.054) within continuous willow habitats. Vagrant shrews were positively associated with plant biomass, vegetation height, and soil moisture. Small mammal habitat associations from my study sites in Bear Valley are in agreement with the literature, suggesting relatively consistent patterns in species-habitat associations. Distribution of small mammal species differed among pastures probably as a result of historical management practices. Alterations of riparian zone structure from historical management practices were evident in the study area, including elimination or decreased willow density, channel entrenchment, and invasion of riparian areas by xeric vegetation. Western jumping mice are apparently the most sensitive species in this area, requiring dense willow stands, suggesting that jumping mice could serve as an indicator species for riparian habitat condition. Title: Small mammal distribution, abundance and habitat selection in managed riparian habitats of Bear Valley, eastern Oregon Author: Tomas, Walfrido Moraes Riparian zones are critical habitats for management because of their importance for both cattle production and wildlife, and a high potential for resource conflicts. Riparian management should address habitat and microhabitat features that sustain both livestock production and wildlife diversity. I conducted a study to determine how small mammal distributions and abundance differ among 3 structurally different riparian habitats in eastern Oregon. The 3 habitat types, herbaceous, discontinuous willow, and continuous willow, represent a range of habitats typical of riparian zones in central and eastern Oregon. I estimated small mammal population sizes in 9 trap grids placed in riparian zones using capture-recapture techniques. Four species of small mammals were captured during 7 trapping periods from August 1994 to September 1995. Small mammal distributions and population sizes of each species varied both within and among riparian pastures. Montane voles (Microtus montanus) were the most abundant species in all grids. Deer mice (Peromyscus maniculatus) had high population sizes in grids with low montane vole populations and moderate to high willow cover. Competition with voles appeared to occur in riparian habitats of Bear Valley, and influenced the distribution and numbers of deer mice. Western jumping mice (Zapus princeps) were captured at relatively low numbers and almost exclusively in continuous willow habitats. Vagrant shrews (Sorex vagrans) were captured on all grids, and population sizes were small. Haying negatively affected survival rates of voles. Biomass, vegetation height, and percent ground cover were the habitat variables most frequently associated with occurrence of montane voles in Bear Valley. The probability of occurrence of this species was positively correlated with these habitat variables. Deer mice probability of occurrence was positively correlated with percent ground cover, plant biomass, and soil moisture. Most deer mice captures occurred in continuous willow habitats, and the number of captures increased with willow basal cover (R²=0.7579, P<0.001). Western jumping mice occurrence was positively correlated with plant biomass and soil moisture, and negatively correlated with distance from willow and percent ground cover. Western jumping mice also were more frequently captured in willow than nonwillow vegetation associations (P=0.054) within continuous willow habitats. Vagrant shrews were positively associated with plant biomass, vegetation height, and soil moisture. Small mammal habitat associations from my study sites in Bear Valley are in agreement with the literature, suggesting relatively consistent patterns in species-habitat associations. Distribution of small mammal species differed among pastures probably as a result of historical management practices. Alterations of riparian zone structure from historical management practices were evident in the study area, including elimination or decreased willow density, channel entrenchment, and invasion of riparian areas by xeric vegetation. Western jumping mice are apparently the most sensitive species in this area, requiring dense willow stands, suggesting that jumping mice could serve as an indicator species for riparian habitat condition. Close

• 36. [Article] Population dynamics of three early seral herb species in Pacific Northwest forests

  I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and ...

  Citation × Citation Citation Abstract Copy Title: Population dynamics of three early seral herb species in Pacific Northwest forests Author: Hanson, D. Eric I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and extirpation in Pacific Northwest Douglas-fir forests. Factors affecting the species' frequency and abundance in forest communities were evaluated. Their population dynamics were modeled and field experiments examined nitrogen fertilization and competition effects on population parameters. Experimental variation made the population models stochastic and sequential transition matrices incorporated the effects of competition into them. Plant community ordination suggested a negative relationship between foxglove and elevation. Indicator species analysis revealed that foxglove is favored by disturbance, i.e., broadcast silvicultural treatments, and by high site productivity, while fireweed responds to low productivity and lack of disturbance. Regression analysis related the species' frequency and cover to factors such as stand age, elevation, and UTM meters east. Simulated woodland groundsel population increased most rapidly. Increased competition tended to reduce its biomass accumulation and seed production per plant but did not affect seeds produced per unit area. Competition also reduced established immature plant survival. Incorporating these factors into the population model, the rate of population growth declined. The projected foxglove population grew at a lower rate than did woodland groundsel but faster than fireweed. Foxglove was adversely affected by competition, which generally reduced its size, biomass, and seed production. Interspecific competition reduced established plant survival, rosette persistence, perenniation, and flowering. Nitrogen fertilization stimulated seed germination, rosette persistence, and flowering but decreased perenniation. Nitrogen fertilization rate did not influence population growth when modeled but application timing did. Nitrogen applied at transplanting resulted in extinction of the population. Transplanting one year after fertilization resulted in constant population growth. Fireweed, with the most complex life cycle, had the lowest population growth rate. Its persistence was entirely due to vegetative reproduction--without it the population would rapidly become extinct. Competition and fertilization had little effect on this species and population projections based on the field experiments indicated constant growth. These results suggest life history and competitive ability regulate succession of pioneer species in Douglas-fir forests and increases population persistence comes at the expense of their growth rate. Title: Population dynamics of three early seral herb species in Pacific Northwest forests Author: Hanson, D. Eric I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and extirpation in Pacific Northwest Douglas-fir forests. Factors affecting the species' frequency and abundance in forest communities were evaluated. Their population dynamics were modeled and field experiments examined nitrogen fertilization and competition effects on population parameters. Experimental variation made the population models stochastic and sequential transition matrices incorporated the effects of competition into them. Plant community ordination suggested a negative relationship between foxglove and elevation. Indicator species analysis revealed that foxglove is favored by disturbance, i.e., broadcast silvicultural treatments, and by high site productivity, while fireweed responds to low productivity and lack of disturbance. Regression analysis related the species' frequency and cover to factors such as stand age, elevation, and UTM meters east. Simulated woodland groundsel population increased most rapidly. Increased competition tended to reduce its biomass accumulation and seed production per plant but did not affect seeds produced per unit area. Competition also reduced established immature plant survival. Incorporating these factors into the population model, the rate of population growth declined. The projected foxglove population grew at a lower rate than did woodland groundsel but faster than fireweed. Foxglove was adversely affected by competition, which generally reduced its size, biomass, and seed production. Interspecific competition reduced established plant survival, rosette persistence, perenniation, and flowering. Nitrogen fertilization stimulated seed germination, rosette persistence, and flowering but decreased perenniation. Nitrogen fertilization rate did not influence population growth when modeled but application timing did. Nitrogen applied at transplanting resulted in extinction of the population. Transplanting one year after fertilization resulted in constant population growth. Fireweed, with the most complex life cycle, had the lowest population growth rate. Its persistence was entirely due to vegetative reproduction--without it the population would rapidly become extinct. Competition and fertilization had little effect on this species and population projections based on the field experiments indicated constant growth. These results suggest life history and competitive ability regulate succession of pioneer species in Douglas-fir forests and increases population persistence comes at the expense of their growth rate. Close

• 37. [Article] Statistical foraminiferal ecology from seasonal samples, central Oregon continental shelf

  This study examined the foraminifera and the ecologic conditions of the benthic environment of the Oregon shelf and the uppermost slope (75-550 m depth) between 143°45' N and 144°40' N. Seasonal collections monitored ...

  Citation × Citation Citation Abstract Copy Title: Statistical foraminiferal ecology from seasonal samples, central Oregon continental shelf Author: Gunther, Fredrick John This study examined the foraminifera and the ecologic conditions of the benthic environment of the Oregon shelf and the uppermost slope (75-550 m depth) between 143°45' N and 144°40' N. Seasonal collections monitored the near-bottom marine environment and the sedimentary substrate at 16 stations. The foraminiferal benthic fauna was examined from eight seasonal stations and two additional stations. Use of a multiple corer provided randomly selected subsarnples of the sediment for ecologic and faunal analyses. Use of water bottles that triggered upon bottom impact provided measurements of the water as close to the bottom as 0. 6 m. Computerized data processing and statistical analyses aided the ecologic and faunal evaluations. The environmental study showed the existence of considerable variation in the hydrography of near-bottom waters, especially between summer and winter (upwelling and non-upwelling) collections at the same station. Upwelling conditions directly affect the benthic Redacted for Privacy environment. In addition, the water at any one place, at least dciring upwelling, was so well mixed that vertical stratification did not exist between 0.6 and 5.0 m off the bottom. Statistically significant sea-. sorial variations in surface sediments at the same station were not observed. The living benthic foraminiferal fauna exhibited considerable within-station variation both in species composition and in specimen size of selected species. The percent abundance of individual dominant species varied in adjacent cores (subsamples) by amounts up to 46%. Living specimens of a single species were found that were three times as large as the smallest living specimen from the same sample, yet there was no evidence of a multimodal size distribution resulting from age classes. The author suggests that the dominant species are aggregated and that the aggregations are colonies of asexually produced siblings. Lack of fit of species-frequency curves to the lognormal distribution indicated that relatively few species are fit to reproduce in a particular environment; most juvenile specimens that enter a particular environment belong to species that will not thrive there and either die or simply maintain growth with little chance of reproductive success. The existence of colonial aggregations of individuals is considered to provide the best explanation of the observed variations between adjacent samples. However, the observed variations could be due to sampling error or to substrate microheterogeneity. A possible natural community of 15 dominant species has been determined for those species that form a consistent part of each other's biologic environment. The community crossed the depth and substrate boundaries upon which the stations were selected and appeared to be a general community for the Oregon outer shelf. The limits of the community appear to be determined mostly by water depth, with approximate boundaries at 75-100 m and somewhere between 200-500 m. Regression analyses to determine the ecologic control on the foraminiferal fauna did not indicate a close correspondence between faunal parameters and environmental variables. Regression analyses to determine the ecologic control on mdividual species indicated that most species depended upon a set of two to four environmental variables rather than upon one single limiting factor. The set for each species was different. Temperature. phosphate concentration and oxygen concentrations were common hydrographic members of sets; percent silt, percent sand, percent clay, organic carbon content and organic nitrogen were common sedimentary members of sets. Title: Statistical foraminiferal ecology from seasonal samples, central Oregon continental shelf Author: Gunther, Fredrick John This study examined the foraminifera and the ecologic conditions of the benthic environment of the Oregon shelf and the uppermost slope (75-550 m depth) between 143°45' N and 144°40' N. Seasonal collections monitored the near-bottom marine environment and the sedimentary substrate at 16 stations. The foraminiferal benthic fauna was examined from eight seasonal stations and two additional stations. Use of a multiple corer provided randomly selected subsarnples of the sediment for ecologic and faunal analyses. Use of water bottles that triggered upon bottom impact provided measurements of the water as close to the bottom as 0. 6 m. Computerized data processing and statistical analyses aided the ecologic and faunal evaluations. The environmental study showed the existence of considerable variation in the hydrography of near-bottom waters, especially between summer and winter (upwelling and non-upwelling) collections at the same station. Upwelling conditions directly affect the benthic Redacted for Privacy environment. In addition, the water at any one place, at least dciring upwelling, was so well mixed that vertical stratification did not exist between 0.6 and 5.0 m off the bottom. Statistically significant sea-. sorial variations in surface sediments at the same station were not observed. The living benthic foraminiferal fauna exhibited considerable within-station variation both in species composition and in specimen size of selected species. The percent abundance of individual dominant species varied in adjacent cores (subsamples) by amounts up to 46%. Living specimens of a single species were found that were three times as large as the smallest living specimen from the same sample, yet there was no evidence of a multimodal size distribution resulting from age classes. The author suggests that the dominant species are aggregated and that the aggregations are colonies of asexually produced siblings. Lack of fit of species-frequency curves to the lognormal distribution indicated that relatively few species are fit to reproduce in a particular environment; most juvenile specimens that enter a particular environment belong to species that will not thrive there and either die or simply maintain growth with little chance of reproductive success. The existence of colonial aggregations of individuals is considered to provide the best explanation of the observed variations between adjacent samples. However, the observed variations could be due to sampling error or to substrate microheterogeneity. A possible natural community of 15 dominant species has been determined for those species that form a consistent part of each other's biologic environment. The community crossed the depth and substrate boundaries upon which the stations were selected and appeared to be a general community for the Oregon outer shelf. The limits of the community appear to be determined mostly by water depth, with approximate boundaries at 75-100 m and somewhere between 200-500 m. Regression analyses to determine the ecologic control on the foraminiferal fauna did not indicate a close correspondence between faunal parameters and environmental variables. Regression analyses to determine the ecologic control on mdividual species indicated that most species depended upon a set of two to four environmental variables rather than upon one single limiting factor. The set for each species was different. Temperature. phosphate concentration and oxygen concentrations were common hydrographic members of sets; percent silt, percent sand, percent clay, organic carbon content and organic nitrogen were common sedimentary members of sets. Close

• 38. [Article] Realized and potential climate responses of lichen and bryophyte communities in a national forest inventory

  Climate and terrestrial vegetation have had mutual feedbacks for nearly five hundred million years, yet both are now departing from recent historical norms, with uncertain implications for forest ecosystems. ...

  Citation × Citation Citation Abstract Copy Title: Realized and potential climate responses of lichen and bryophyte communities in a national forest inventory Author: Smith, Robert J. Climate and terrestrial vegetation have had mutual feedbacks for nearly five hundred million years, yet both are now departing from recent historical norms, with uncertain implications for forest ecosystems. This dissertation outlines the current and potential future climate responses of lichen and bryophyte communities in the United States as part of a national forest inventory. The first task was to identify influences on carbon and nitrogen storage of moss and lichen “ground layers” in subarctic interior Alaska. Nutrient stores were more sensitive to local vegetation and topography than regional macroclimate. Nutrients and biomass were greatest among apparently less disturbed stands. This suggests that climatic changes could diminish ground layer nutrient storage indirectly if they promote intensifying wildfire regimes or expansions of competitive vascular vegetation. Turning to focus on species diversity, the next task was to quantify the strength of relationship between epiphytic lichen community composition and macroclimate across the 4,000 km-long swath of the U.S. Pacific coastal states. The strongest fitting lichen response gradients involved precipitation, temperature, and a heat-moisture index. Lichen indicator species (diagnostic of ten defined climate zones) emerged as useful monitoring tools because their abundance changes could signal shifting climate zone boundaries. After establishing key present-day climatic relationships, the next task was to pinpoint nationwide locations where epiphytic lichen communities will be most vulnerable to species losses under current and future warming scenarios. Novel niche-based metrics revealed greatest vulnerability among supposedly “warm-adapted” communities in southern/lowland locations, contrary to usual assumptions centering on cooler northern/montane habitats. Vulnerability analyses can steer conservation and monitoring attention to specific locations where warming is most expected to affect ecological communities. The final task, to anticipate how warming will impact individual lichen performance, was addressed by quantifying how experimental climate treatments (whole-ecosystem warming and CO2 additions) affected growth of the boreal epiphytic lichen species Evernia mesomorpha. Over just one year, incremental warming and concurrent drying caused progressive growth declines and biomass losses among individual transplants. Such warming-induced biomass losses of epiphytic lichens could precede local population extinctions and regional range contractions. Overall, this dissertation weaves together multiple lines of evidence from nutrient, diversity and growth responses to indicate the ecological effects of climate and climatic changes on vegetation in a national forest inventory context. This work suggests a pathway for integrating lichen and bryophyte responses into nationwide climate monitoring to address emergent interactions between humans, vegetation, and the global climate commons. Title: Realized and potential climate responses of lichen and bryophyte communities in a national forest inventory Author: Smith, Robert J. Climate and terrestrial vegetation have had mutual feedbacks for nearly five hundred million years, yet both are now departing from recent historical norms, with uncertain implications for forest ecosystems. This dissertation outlines the current and potential future climate responses of lichen and bryophyte communities in the United States as part of a national forest inventory. The first task was to identify influences on carbon and nitrogen storage of moss and lichen “ground layers” in subarctic interior Alaska. Nutrient stores were more sensitive to local vegetation and topography than regional macroclimate. Nutrients and biomass were greatest among apparently less disturbed stands. This suggests that climatic changes could diminish ground layer nutrient storage indirectly if they promote intensifying wildfire regimes or expansions of competitive vascular vegetation. Turning to focus on species diversity, the next task was to quantify the strength of relationship between epiphytic lichen community composition and macroclimate across the 4,000 km-long swath of the U.S. Pacific coastal states. The strongest fitting lichen response gradients involved precipitation, temperature, and a heat-moisture index. Lichen indicator species (diagnostic of ten defined climate zones) emerged as useful monitoring tools because their abundance changes could signal shifting climate zone boundaries. After establishing key present-day climatic relationships, the next task was to pinpoint nationwide locations where epiphytic lichen communities will be most vulnerable to species losses under current and future warming scenarios. Novel niche-based metrics revealed greatest vulnerability among supposedly “warm-adapted” communities in southern/lowland locations, contrary to usual assumptions centering on cooler northern/montane habitats. Vulnerability analyses can steer conservation and monitoring attention to specific locations where warming is most expected to affect ecological communities. The final task, to anticipate how warming will impact individual lichen performance, was addressed by quantifying how experimental climate treatments (whole-ecosystem warming and CO2 additions) affected growth of the boreal epiphytic lichen species Evernia mesomorpha. Over just one year, incremental warming and concurrent drying caused progressive growth declines and biomass losses among individual transplants. Such warming-induced biomass losses of epiphytic lichens could precede local population extinctions and regional range contractions. Overall, this dissertation weaves together multiple lines of evidence from nutrient, diversity and growth responses to indicate the ecological effects of climate and climatic changes on vegetation in a national forest inventory context. This work suggests a pathway for integrating lichen and bryophyte responses into nationwide climate monitoring to address emergent interactions between humans, vegetation, and the global climate commons. Close

• 39. [Article] Distribution, structure, and function of marine ecological communities in the northern California Current upwelling ecosystem

  Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification ...

  Citation × Citation Citation Abstract Copy Title: Distribution, structure, and function of marine ecological communities in the northern California Current upwelling ecosystem Author: Reese, Douglas Charles Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification of such marine, biological hotspots would be of great importance to resource managers, conservationists, and research planners, and is consequently a growing area of research. Furthermore, in order to understand how ecosystems function and persist, it is necessary to know how ecological communities are distributed. The overall goal of this study is to provide further understanding regarding the functioning of marine ecosystems in such highly variable environments and to provide information about the distribution and structure of marine communities. Sampling was conducted during June and August of 2000 and 2002 as part of the U.S. GLOBEC mesoscale surveys from Newport, Oregon in the north to Crescent City, California in the south. A geostatistical approach was used to create surfaces used in a GIS to determine the distribution of various community characteristics. Two biological hotspots were identified and determined to persist in space and time, yet differed with respect to biological and physical features and in the amount of area covered. Various community analyses, including nonmetric multidimensional scaling, indicator species analysis, and cluster analysis were used to determine various community properties associated with the hotspots and non-hotspot regions. Results indicate that nekton biological hotspots in the northern California Current persist across differing environmental and biological conditions, although upwelling-based hotspots may be more susceptible to climatic conditions than retention-based hotspots. Analyses of the distribution of the functional groups within the region indicate that the predominant biological activity is spatially nonrandom and occurs within persistent, localized areas. Analyses of species associations suggest a moderate degree of redundancy. The presence of such complementary species within functional groups may confer the stability observed within these systems. The finding that large regional areas are composed of smaller, localized hotspots where a predominant amount of biological activity is occurring, suggests that the evaluation of large marine ecosystems may lead to erroneous or misleading results if they do not consider the more persistent, localized biological hotspots. Title: Distribution, structure, and function of marine ecological communities in the northern California Current upwelling ecosystem Author: Reese, Douglas Charles Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification of such marine, biological hotspots would be of great importance to resource managers, conservationists, and research planners, and is consequently a growing area of research. Furthermore, in order to understand how ecosystems function and persist, it is necessary to know how ecological communities are distributed. The overall goal of this study is to provide further understanding regarding the functioning of marine ecosystems in such highly variable environments and to provide information about the distribution and structure of marine communities. Sampling was conducted during June and August of 2000 and 2002 as part of the U.S. GLOBEC mesoscale surveys from Newport, Oregon in the north to Crescent City, California in the south. A geostatistical approach was used to create surfaces used in a GIS to determine the distribution of various community characteristics. Two biological hotspots were identified and determined to persist in space and time, yet differed with respect to biological and physical features and in the amount of area covered. Various community analyses, including nonmetric multidimensional scaling, indicator species analysis, and cluster analysis were used to determine various community properties associated with the hotspots and non-hotspot regions. Results indicate that nekton biological hotspots in the northern California Current persist across differing environmental and biological conditions, although upwelling-based hotspots may be more susceptible to climatic conditions than retention-based hotspots. Analyses of the distribution of the functional groups within the region indicate that the predominant biological activity is spatially nonrandom and occurs within persistent, localized areas. Analyses of species associations suggest a moderate degree of redundancy. The presence of such complementary species within functional groups may confer the stability observed within these systems. The finding that large regional areas are composed of smaller, localized hotspots where a predominant amount of biological activity is occurring, suggests that the evaluation of large marine ecosystems may lead to erroneous or misleading results if they do not consider the more persistent, localized biological hotspots. Close

• 40. [Article] Evaluating benthic macroinvertebrates as bio-indicators of freshwater habitat quality in an eastern Oregon agro-ecosystem

  The effect of anthropogenic disturbance on river systems is gaining attention, and concerns about the state of freshwater natural resources are increasing globally, as are efforts to restore habitat that ...

  Citation × Citation Citation Abstract Copy Title: Evaluating benthic macroinvertebrates as bio-indicators of freshwater habitat quality in an eastern Oregon agro-ecosystem Author: Scherr, Melissa A. The effect of anthropogenic disturbance on river systems is gaining attention, and concerns about the state of freshwater natural resources are increasing globally, as are efforts to restore habitat that has been degraded by disturbance. In rivers, non-point source pollution affects the physical characteristics of the habitat and the endemic biotic assemblages. Aquatic macroinvertebrates are numerous and exhibit graded responses to various types of disturbance in the river, and may be used as indicators of habitat conditions. In this dissertation, macroinvertebrates were examined as bioindicators in the Umatilla River in eastern Oregon. The first study is a bioassessment of the impacts of agriculture on the benthic macroinvertebrate community in adjacent streams. The results of this study show that there are physical differences in habitat associated with adjacent land use, and the macroinvertebrate communities responded to these differences with changes in taxa richness and evenness. Indicator species analysis identified thirteen taxa which were indicative of habitat conditions associated with ideal habitat used as a reference condition, degraded habitat associated with agricultural land use, and transitional habitat associated with conservation/restoration management. The second study is a laboratory study in which the effects of temperature of a common mayfly nymph, Epeorus albertae (McDunnough) (Ephemeroptera: Heptageniidae) were evaluated. The study showed that not only the developmental rate of the nymphs was affected by temperature treatment (within a range of 18°C and 28°C), but the location of accumulated body tissues over time varied by temperature, with significant difference in the type of growth observed for insects held at the highest temperature. The third study examined the response of six indicator taxa to environmental variables as predictors of abundance in a non-parametric multiplicative regression. This study found that for all taxa examined, the two best predictors of abundance in the Umatilla River were turbidity and conductivity. Increased turbidity and conductivity are common effects of intensive agriculture in streams located in agro-ecosystems, but may potentially be mitigated by vegetative buffer strips and sustainable land use practices. Long term agricultural disturbance in the landscape has been shown to have lasting effects in the ecosystem which may be further exacerbated as global climate change increases dependence on freshwater resources. Understanding anthropogenic impacts on organismal communities and natural resources is vital to establishment of effective conservation, restoration, and maintenance of a healthy ecosystem. Title: Evaluating benthic macroinvertebrates as bio-indicators of freshwater habitat quality in an eastern Oregon agro-ecosystem Author: Scherr, Melissa A. The effect of anthropogenic disturbance on river systems is gaining attention, and concerns about the state of freshwater natural resources are increasing globally, as are efforts to restore habitat that has been degraded by disturbance. In rivers, non-point source pollution affects the physical characteristics of the habitat and the endemic biotic assemblages. Aquatic macroinvertebrates are numerous and exhibit graded responses to various types of disturbance in the river, and may be used as indicators of habitat conditions. In this dissertation, macroinvertebrates were examined as bioindicators in the Umatilla River in eastern Oregon. The first study is a bioassessment of the impacts of agriculture on the benthic macroinvertebrate community in adjacent streams. The results of this study show that there are physical differences in habitat associated with adjacent land use, and the macroinvertebrate communities responded to these differences with changes in taxa richness and evenness. Indicator species analysis identified thirteen taxa which were indicative of habitat conditions associated with ideal habitat used as a reference condition, degraded habitat associated with agricultural land use, and transitional habitat associated with conservation/restoration management. The second study is a laboratory study in which the effects of temperature of a common mayfly nymph, Epeorus albertae (McDunnough) (Ephemeroptera: Heptageniidae) were evaluated. The study showed that not only the developmental rate of the nymphs was affected by temperature treatment (within a range of 18°C and 28°C), but the location of accumulated body tissues over time varied by temperature, with significant difference in the type of growth observed for insects held at the highest temperature. The third study examined the response of six indicator taxa to environmental variables as predictors of abundance in a non-parametric multiplicative regression. This study found that for all taxa examined, the two best predictors of abundance in the Umatilla River were turbidity and conductivity. Increased turbidity and conductivity are common effects of intensive agriculture in streams located in agro-ecosystems, but may potentially be mitigated by vegetative buffer strips and sustainable land use practices. Long term agricultural disturbance in the landscape has been shown to have lasting effects in the ecosystem which may be further exacerbated as global climate change increases dependence on freshwater resources. Understanding anthropogenic impacts on organismal communities and natural resources is vital to establishment of effective conservation, restoration, and maintenance of a healthy ecosystem. Close