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• 351. [Article] Forest disturbance across the conterminous United States from 1985-2012: The emerging dominance of forest decline

  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: Forest disturbance across the conterminous United States from 1985-2012: The emerging dominance of forest decline Author: Yang, Zhiqiang, Stehman, Stephen V., Cohen, Warren B., et al. 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/forest-ecology-and-management/ Title: Forest disturbance across the conterminous United States from 1985-2012: The emerging dominance of forest decline Author: Yang, Zhiqiang, Stehman, Stephen V., Cohen, Warren B., et al. 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/forest-ecology-and-management/ Close

• 352. [Article] Alkenone sea-surface temperatures and carbon burial at site 846 (Eastern Equatorial Pacific Ocean) : the last 1.3 M.Y.

  We analyzed the unsaturation ratio (U k/37 ) of long-chain ketones—a molecular sea-surface temperature (SST) indicator—concentrations of carbonate and organic carbon in sediments from Site 846 in the eastern ...

  Citation × Citation Citation Abstract Copy Title: Alkenone sea-surface temperatures and carbon burial at site 846 (Eastern Equatorial Pacific Ocean) : the last 1.3 M.Y. Author: Schulz-Bull, D., Emeis, K.-C., Doose, H., Mix, Alan C. We analyzed the unsaturation ratio (U k/37 ) of long-chain ketones—a molecular sea-surface temperature (SST) indicator—concentrations of carbonate and organic carbon in sediments from Site 846 in the eastern equatorial Pacific Ocean. Based on an isotopic age model for the composite depth section of 0-46 m below seafloor and on estimates of sediment density, accumulation rates of these biogenic compounds were calculated. Our combined temperature and biogenic flux record traces conditions at the origin of the South Equatorial Current over the last 1.3 m.y. S STs have fluctuated considerably over the interval studied. A long trend of gradual decrease from 24°C at 1.3 Ma ends between 500 and 400 Ka, when lowest values of 19°C were reached. Since this time, the temperature data indicate a warming trend to the Holocene modulated by high-amplitude variation (19° to 27°C). The inversion of the trend between 400 and 500 Ka coincides with maximal accumulation rates of carbonate, which since then have decreased. In contrast, organic carbon accumulation since then has increased in variability and in absolute values. On shorter time scales, the records show a strong link to the global climatic background. Since 1.3 Ma, carbonate (0.2-3 g/cm² k.y.¯¹) and organic carbon accumulation rates (2-30 mg/cm² k.y¯¹) were consistently high (more than twice their modern values and those of interglacials) during glacial maxima in the benthic isotope record, when temperatures were low. However, cross-spectral analyses with the δ¹⁸O record suggest that variation in organic carbon flux is not linked directly to variations in SST. Temperature maxima in our record led interglacial events by 7 k.y. in the 100-k.y. eccentricity cycle and by 5 k.y. in the 41-k.y. obliquity cycle. In contrast, maxima in organic carbon accumulation lag behind glacial maxima and low temperatures by 14 k.y. in the eccentricity cycle. On glacial/interglacial time scales, a prominent influence on SST—but not on organic carbon burial—at Site 846 appears to be the advection of cold water into the South Equatorial Current. Title: Alkenone sea-surface temperatures and carbon burial at site 846 (Eastern Equatorial Pacific Ocean) : the last 1.3 M.Y. Author: Schulz-Bull, D., Emeis, K.-C., Doose, H., Mix, Alan C. We analyzed the unsaturation ratio (U k/37 ) of long-chain ketones—a molecular sea-surface temperature (SST) indicator—concentrations of carbonate and organic carbon in sediments from Site 846 in the eastern equatorial Pacific Ocean. Based on an isotopic age model for the composite depth section of 0-46 m below seafloor and on estimates of sediment density, accumulation rates of these biogenic compounds were calculated. Our combined temperature and biogenic flux record traces conditions at the origin of the South Equatorial Current over the last 1.3 m.y. S STs have fluctuated considerably over the interval studied. A long trend of gradual decrease from 24°C at 1.3 Ma ends between 500 and 400 Ka, when lowest values of 19°C were reached. Since this time, the temperature data indicate a warming trend to the Holocene modulated by high-amplitude variation (19° to 27°C). The inversion of the trend between 400 and 500 Ka coincides with maximal accumulation rates of carbonate, which since then have decreased. In contrast, organic carbon accumulation since then has increased in variability and in absolute values. On shorter time scales, the records show a strong link to the global climatic background. Since 1.3 Ma, carbonate (0.2-3 g/cm² k.y.¯¹) and organic carbon accumulation rates (2-30 mg/cm² k.y¯¹) were consistently high (more than twice their modern values and those of interglacials) during glacial maxima in the benthic isotope record, when temperatures were low. However, cross-spectral analyses with the δ¹⁸O record suggest that variation in organic carbon flux is not linked directly to variations in SST. Temperature maxima in our record led interglacial events by 7 k.y. in the 100-k.y. eccentricity cycle and by 5 k.y. in the 41-k.y. obliquity cycle. In contrast, maxima in organic carbon accumulation lag behind glacial maxima and low temperatures by 14 k.y. in the eccentricity cycle. On glacial/interglacial time scales, a prominent influence on SST—but not on organic carbon burial—at Site 846 appears to be the advection of cold water into the South Equatorial Current. Close

• 353. [Article] Modeling protein structure at atomic resolution

  This thesis includes three studies involving different aspects of modeling protein structure. The first study illustrates the levels of insight available from atomic-resolution protein structures. The ...

  Citation × Citation Citation Abstract Copy Title: Modeling protein structure at atomic resolution Author: Berkholz, Donald S. This thesis includes three studies involving different aspects of modeling protein structure. The first study illustrates the levels of insight available from atomic-resolution protein structures. The second study derives general trends of protein geometry from atomic-resolution structures and shows their implications for modeling. The third study creates a model of a protein and uses it to derive new biological insights. In the first study, a series of structures were analyzed from human glutathione reductase, a biomedically relevant enzyme. Newly accessible at atomic resolution is structural evidence showing the catalytic importance of active-site compression, which additionally causes distortions from standard geometry that further enhance catalytic power. Another aspect of geometry visible at atomic resolution is the remarkably ideal positioning of atoms for catalysis. The stereoelectronic control displayed by compression and geometric preorganization provides insight into the origins of catalytic power. The second study builds upon quantum-mechanics calculations and empirical analyses of protein structure from the 1990s that showed the concept of a single ideal value for backbone geometry was wrong. Here, a nonredundant set of protein structures at atomic resolution is probed to better define the dependence of backbone geometry upon the conformation of the backbone torsion angles Φ and Ψ. The set was taken from the Protein Geometry Database created here (http://pgd.science.oregonstate.edu/). The trends seen make structural sense and lay the groundwork for a paradigm shift in the concept of ideal geometry. A conformation-dependent library accounting for these trends has the potential to improve modeling accuracy. In the third study, a model of the tumor-suppressor merlin is created and used to gain new understanding of merlin's function. Merlin is the only known cytoskeletal tumor suppressor, and loss of functional merlin results in neurofibromatosis 2, characterized by nervous-system tumors, cataracts, and skin tumors. Clear errors were evident in available automatically created models, driving the need for a reliable structure. Merlin and its homologs have distinct functions, so the differences between them were probed, suggesting critical functional clusters. A new technique developed here for discovering gains and losses of function should be generally applicable to any two protein subfamilies with distinct functions. Title: Modeling protein structure at atomic resolution Author: Berkholz, Donald S. This thesis includes three studies involving different aspects of modeling protein structure. The first study illustrates the levels of insight available from atomic-resolution protein structures. The second study derives general trends of protein geometry from atomic-resolution structures and shows their implications for modeling. The third study creates a model of a protein and uses it to derive new biological insights. In the first study, a series of structures were analyzed from human glutathione reductase, a biomedically relevant enzyme. Newly accessible at atomic resolution is structural evidence showing the catalytic importance of active-site compression, which additionally causes distortions from standard geometry that further enhance catalytic power. Another aspect of geometry visible at atomic resolution is the remarkably ideal positioning of atoms for catalysis. The stereoelectronic control displayed by compression and geometric preorganization provides insight into the origins of catalytic power. The second study builds upon quantum-mechanics calculations and empirical analyses of protein structure from the 1990s that showed the concept of a single ideal value for backbone geometry was wrong. Here, a nonredundant set of protein structures at atomic resolution is probed to better define the dependence of backbone geometry upon the conformation of the backbone torsion angles Φ and Ψ. The set was taken from the Protein Geometry Database created here (http://pgd.science.oregonstate.edu/). The trends seen make structural sense and lay the groundwork for a paradigm shift in the concept of ideal geometry. A conformation-dependent library accounting for these trends has the potential to improve modeling accuracy. In the third study, a model of the tumor-suppressor merlin is created and used to gain new understanding of merlin's function. Merlin is the only known cytoskeletal tumor suppressor, and loss of functional merlin results in neurofibromatosis 2, characterized by nervous-system tumors, cataracts, and skin tumors. Clear errors were evident in available automatically created models, driving the need for a reliable structure. Merlin and its homologs have distinct functions, so the differences between them were probed, suggesting critical functional clusters. A new technique developed here for discovering gains and losses of function should be generally applicable to any two protein subfamilies with distinct functions. Close

• 354. [Article] Evaluation of the Oregon bicycle helmet use law on bicycle helmet usage and bicycle-related head injuries

  The objectives of this study were to 1) assess the effectiveness of the law in increasing helmet use and compare methods of measuring helmet use, and 2) determine the impact of the law on bicycle-related ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of the Oregon bicycle helmet use law on bicycle helmet usage and bicycle-related head injuries Author: Ni, Hanyu The objectives of this study were to 1) assess the effectiveness of the law in increasing helmet use and compare methods of measuring helmet use, and 2) determine the impact of the law on bicycle-related head injury and fatalities. To measure changes in helmet use by children under 16 years of age, we conducted three statewide pre- and post-law surveys: direct observations, telephone surveys of parents, and classroom surveys of students. We identified bicycle-related head injury cases during July 1989 -, June 1995 through the Oregon Trauma Registry and Vital Statistical Department. Time series analysis was employed to determine if the secular trend and intervention were actual effects rather than random noise. Observed helmet use increased from 24.5% pre-law to 49.3% post-law (P<0.01). Classroom survey self-reported "always" use of helmets increased from 14.7% to 39.4% afterwards (P₍₂₎<0.01). Younger girls were more likely to comply the law. Helmet ownership increased from 5 1.5% pre-law to 75.5% afterwards on the student surveys (P₍₂₎<0.01) and from 67.4% to 83.9% on the parent surveys (P₍₂₎<0.01). The increase in helmet ownership was greater among children with low household-income. The results obtained from classroom surveys and direct observations were correlated (r=0.76, P<0.0l). The majority of students (87.8%) and parents (95.4%) knew about the Oregon bicycle helmet law, but only half of the students thought the law was a "good idea." One year after the law was effective, the incidence rate of statewide bicycle-related head injury decreased from 3.9 per 100,000 person-years pre-law to 2.9 per 100,000 person-years (P₍₂₎<0.001). The decrease was most profound in children under 16 years of age. For children under 16 years of age, the decreasing trend of bicycle-related head injuries appeared to mirror the increasing trend of helmet usage. We conclude that 1) the law increased helmet use; 2) the law helped reduce the bicycle-related severe head injuries; and 3) although use estimates differ, all helmet surveys showed similar degrees of pre- and post-law change. Our results suggest that the laws may be an effective approach to increase helmet use and reduce head injury in other states. Title: Evaluation of the Oregon bicycle helmet use law on bicycle helmet usage and bicycle-related head injuries Author: Ni, Hanyu The objectives of this study were to 1) assess the effectiveness of the law in increasing helmet use and compare methods of measuring helmet use, and 2) determine the impact of the law on bicycle-related head injury and fatalities. To measure changes in helmet use by children under 16 years of age, we conducted three statewide pre- and post-law surveys: direct observations, telephone surveys of parents, and classroom surveys of students. We identified bicycle-related head injury cases during July 1989 -, June 1995 through the Oregon Trauma Registry and Vital Statistical Department. Time series analysis was employed to determine if the secular trend and intervention were actual effects rather than random noise. Observed helmet use increased from 24.5% pre-law to 49.3% post-law (P<0.01). Classroom survey self-reported "always" use of helmets increased from 14.7% to 39.4% afterwards (P₍₂₎<0.01). Younger girls were more likely to comply the law. Helmet ownership increased from 5 1.5% pre-law to 75.5% afterwards on the student surveys (P₍₂₎<0.01) and from 67.4% to 83.9% on the parent surveys (P₍₂₎<0.01). The increase in helmet ownership was greater among children with low household-income. The results obtained from classroom surveys and direct observations were correlated (r=0.76, P<0.0l). The majority of students (87.8%) and parents (95.4%) knew about the Oregon bicycle helmet law, but only half of the students thought the law was a "good idea." One year after the law was effective, the incidence rate of statewide bicycle-related head injury decreased from 3.9 per 100,000 person-years pre-law to 2.9 per 100,000 person-years (P₍₂₎<0.001). The decrease was most profound in children under 16 years of age. For children under 16 years of age, the decreasing trend of bicycle-related head injuries appeared to mirror the increasing trend of helmet usage. We conclude that 1) the law increased helmet use; 2) the law helped reduce the bicycle-related severe head injuries; and 3) although use estimates differ, all helmet surveys showed similar degrees of pre- and post-law change. Our results suggest that the laws may be an effective approach to increase helmet use and reduce head injury in other states. Close

• 355. [Article] The effect of thinning intensity upon understory growth and species composition in an Oregon Coast Range Pseudotsuga menziesii stand

  Cover, frequency, and biomass of under story vegetation were estimated on 14 study plots in a central Oregon Coast Range Pseudotsuga menziesii stand. The treatments included a control and three different ...

  Citation × Citation Citation Abstract Copy Title: The effect of thinning intensity upon understory growth and species composition in an Oregon Coast Range Pseudotsuga menziesii stand Author: Witler, Jerome Warren Cover, frequency, and biomass of under story vegetation were estimated on 14 study plots in a central Oregon Coast Range Pseudotsuga menziesii stand. The treatments included a control and three different thinning intensities. Basal area of active growing stock, defined as young-growth P. menziesii with diameter at breast height of 7.6 inches (19.3 cm) or greater, determines thinning intensity. Heavily thinned stands are maintained between 100 and 130 square feet per acre (23-30 m²/ha) of active growing stock, moderate thinnings between 130 and 160 square feet per acre (30-37 m²/ha), and light thinnings between 160 and 190 square feet per acre (37-44 m²/ha). The amount of canopy opening and of light reaching the understory were found to be negatively correlated with the log of active growing stock basal area. Despite much plot-to-plot variation in cover, several trends corresponding with thinning treatment were detected. Berberis nervosa and Eurhynchium oreganum are the dominant species on unthinned plots, whereas Pteridium aquilinum and E. oreganum predominate on all thinning treatments. Herbaceous species are most responsive to thinning, with highest cover in the moderate and heavy thinnings. Herbs showing the greatest increases with thinning are Pteridium aquilinum, Campanula scouleri, Collomia heterophylla, Festuca occidentalis, Hieracium albiflorum, and Trientalis latifolia. Further, a few species are confined to either thinned or to unthinned plots, but of these species, only Lotus crassifolius and Lupinus latifolius, both on thinned plots, occur with relatively high frequencies. No species that attains high cover or frequency on any treatment significantly decreases with thinning intensity. Trends in understory biomass are similar to those for cover and frequency, though sampling error was larger for the biomass estimates. In general, cover and frequency data on woody plants show no clear response to thinning. Biomass estimates, especially for the large shrubs, show a trend towards increased woody vegetation with thinning intensity. Data on stem density, however, best indicate that some large woody plants are responding to thinning. Large woody stems are scattered widely throughout the plots, but where the shrubs Acer circinatum, Corylus cornuta, and Holodiscus discolor, in particular, occur on thinned plots, they often are growing in clumps of many young, erect stems. Such clumps do not occur on unthinned plots. These findings suggest the hypothesis that the occurrence of these woody plants in the original forest was infrequent and that the clumps result vegetatively from the original stems or root systems in response to thinning. Understory competition does not prevent initial establishment of Pseudotsuga menziesii seedlings on the thinned plots. Although stocking levels for P. menziesii seedlings on the thinned plots are high, growth is slow, and few seedlings survive past the fifth year. Few tree seedlings are found on the unthinned plots. Title: The effect of thinning intensity upon understory growth and species composition in an Oregon Coast Range Pseudotsuga menziesii stand Author: Witler, Jerome Warren Cover, frequency, and biomass of under story vegetation were estimated on 14 study plots in a central Oregon Coast Range Pseudotsuga menziesii stand. The treatments included a control and three different thinning intensities. Basal area of active growing stock, defined as young-growth P. menziesii with diameter at breast height of 7.6 inches (19.3 cm) or greater, determines thinning intensity. Heavily thinned stands are maintained between 100 and 130 square feet per acre (23-30 m²/ha) of active growing stock, moderate thinnings between 130 and 160 square feet per acre (30-37 m²/ha), and light thinnings between 160 and 190 square feet per acre (37-44 m²/ha). The amount of canopy opening and of light reaching the understory were found to be negatively correlated with the log of active growing stock basal area. Despite much plot-to-plot variation in cover, several trends corresponding with thinning treatment were detected. Berberis nervosa and Eurhynchium oreganum are the dominant species on unthinned plots, whereas Pteridium aquilinum and E. oreganum predominate on all thinning treatments. Herbaceous species are most responsive to thinning, with highest cover in the moderate and heavy thinnings. Herbs showing the greatest increases with thinning are Pteridium aquilinum, Campanula scouleri, Collomia heterophylla, Festuca occidentalis, Hieracium albiflorum, and Trientalis latifolia. Further, a few species are confined to either thinned or to unthinned plots, but of these species, only Lotus crassifolius and Lupinus latifolius, both on thinned plots, occur with relatively high frequencies. No species that attains high cover or frequency on any treatment significantly decreases with thinning intensity. Trends in understory biomass are similar to those for cover and frequency, though sampling error was larger for the biomass estimates. In general, cover and frequency data on woody plants show no clear response to thinning. Biomass estimates, especially for the large shrubs, show a trend towards increased woody vegetation with thinning intensity. Data on stem density, however, best indicate that some large woody plants are responding to thinning. Large woody stems are scattered widely throughout the plots, but where the shrubs Acer circinatum, Corylus cornuta, and Holodiscus discolor, in particular, occur on thinned plots, they often are growing in clumps of many young, erect stems. Such clumps do not occur on unthinned plots. These findings suggest the hypothesis that the occurrence of these woody plants in the original forest was infrequent and that the clumps result vegetatively from the original stems or root systems in response to thinning. Understory competition does not prevent initial establishment of Pseudotsuga menziesii seedlings on the thinned plots. Although stocking levels for P. menziesii seedlings on the thinned plots are high, growth is slow, and few seedlings survive past the fifth year. Few tree seedlings are found on the unthinned plots. Close

• 356. [Article] A geologic and mineralogic study of the Bethlehem Copper property at Highland Valley, British Columbia

  The Bethlehem Copper Mine, a porphyry copper deposit, is situated near the geographical center of the Guichon Creek batholith. The Guichon Creek batholith is located on the east flank of the Canadian Coast ...

  Citation × Citation Citation Abstract Copy Title: A geologic and mineralogic study of the Bethlehem Copper property at Highland Valley, British Columbia Author: Wood, Allan Deane, 1936- The Bethlehem Copper Mine, a porphyry copper deposit, is situated near the geographical center of the Guichon Creek batholith. The Guichon Creek batholith is located on the east flank of the Canadian Coast Range in south central British Columbia approximately 250 miles northeast of Vancouver, B. C. The batholith trends northerly, is 40 miles long, 16 miles wide and divided in half by a broad easterly trending saddle, the Highland Valley. Moreover, it is composite and consists of two principal phases, an older quartz diorite and a younger granodiorite. The Bethlehem copper deposit is situated on the contact between these two phases. Seven igneous rock types and several breccia bodies have been recognized. The Guichon quartz diorite, Early Jurassic in age, has been intruded by Bethlehem quartz diorite, leucocratic porphyritic dacite, granite, granodiorite, dacite porphyry, and mesocratic porphyritic dacite. The Bethlehem quartz diorite is thought to be a marginal or cupola phase of the granodiorite. Dacite porphyry, granodiorite, mesocratic porphyritic dacite and possibly leucocratic porphyritic dacite occur as dike rocks. The breccia bodies are believed to be related to the emplacement of Bethlehem quartz diorite and leucocratic porphyritic dacite with coincident or later explosive events. Mining operations in the Jersey pit have exposed Guichon quartz diorite, Bethlehem quartz diorite, dacite porphyry and breccia. Bethlehem quartz diorite and breccia nearly circumscribe a huge block of Guichon quartz diorite some 700 feet in diameter. All rocks in the pit have been faulted, fractured, mineralized and hydrothermally altered. Faults consist of a northerly trending, west dipping essentially parallel set. Obvious fractures are related to faults while the more significant, indistinct, and randomly orientated hairline fractures that control mineralization apparently are not. Chalcopyrite, bornite and other metallic minerals occur as scattered grains on fracture surfaces or less commonly as disseminations replacing secondary mafics. The degree and extent of mineralization is a function of permeability produced by fracturing. Hydrothermal alteration associated with the Jersey pit is of both the propylitic and argillic types. Propylitic alteration fringes and Jersey ore body and is characterized by the development of epidote and chlorite at the expense of primary hornblende, biotite, and less commonly plagioclase. Argillic alteration is restricted to the central area of the pit, as is most of the significant mineralization and is characterized by strong lime leaching and the development of fine grained, but optically unresolvable, minerals believed to be one or more types of clay minerals. Title: A geologic and mineralogic study of the Bethlehem Copper property at Highland Valley, British Columbia Author: Wood, Allan Deane, 1936- The Bethlehem Copper Mine, a porphyry copper deposit, is situated near the geographical center of the Guichon Creek batholith. The Guichon Creek batholith is located on the east flank of the Canadian Coast Range in south central British Columbia approximately 250 miles northeast of Vancouver, B. C. The batholith trends northerly, is 40 miles long, 16 miles wide and divided in half by a broad easterly trending saddle, the Highland Valley. Moreover, it is composite and consists of two principal phases, an older quartz diorite and a younger granodiorite. The Bethlehem copper deposit is situated on the contact between these two phases. Seven igneous rock types and several breccia bodies have been recognized. The Guichon quartz diorite, Early Jurassic in age, has been intruded by Bethlehem quartz diorite, leucocratic porphyritic dacite, granite, granodiorite, dacite porphyry, and mesocratic porphyritic dacite. The Bethlehem quartz diorite is thought to be a marginal or cupola phase of the granodiorite. Dacite porphyry, granodiorite, mesocratic porphyritic dacite and possibly leucocratic porphyritic dacite occur as dike rocks. The breccia bodies are believed to be related to the emplacement of Bethlehem quartz diorite and leucocratic porphyritic dacite with coincident or later explosive events. Mining operations in the Jersey pit have exposed Guichon quartz diorite, Bethlehem quartz diorite, dacite porphyry and breccia. Bethlehem quartz diorite and breccia nearly circumscribe a huge block of Guichon quartz diorite some 700 feet in diameter. All rocks in the pit have been faulted, fractured, mineralized and hydrothermally altered. Faults consist of a northerly trending, west dipping essentially parallel set. Obvious fractures are related to faults while the more significant, indistinct, and randomly orientated hairline fractures that control mineralization apparently are not. Chalcopyrite, bornite and other metallic minerals occur as scattered grains on fracture surfaces or less commonly as disseminations replacing secondary mafics. The degree and extent of mineralization is a function of permeability produced by fracturing. Hydrothermal alteration associated with the Jersey pit is of both the propylitic and argillic types. Propylitic alteration fringes and Jersey ore body and is characterized by the development of epidote and chlorite at the expense of primary hornblende, biotite, and less commonly plagioclase. Argillic alteration is restricted to the central area of the pit, as is most of the significant mineralization and is characterized by strong lime leaching and the development of fine grained, but optically unresolvable, minerals believed to be one or more types of clay minerals. Close

• 357. [Article] Early plant biomass trends following forest site preparation on the Oregon Coast Range

  The vegetation following forest site preparation was examined in ten clearcut units located in the western Oregon Coast Range. The site preparation techniques used in these units included scarification, ...

  Citation × Citation Citation Abstract Copy Title: Early plant biomass trends following forest site preparation on the Oregon Coast Range Author: Malavasi, Ubirajara Contro The vegetation following forest site preparation was examined in ten clearcut units located in the western Oregon Coast Range. The site preparation techniques used in these units included scarification, slash burning, and chemical spraying. The ages of the clearcut units studied varied from one to nine growing seasons for the scarification treatment, two to ten for the slash burning treatment, and two to six for the spraying treatment. The survey of the vegetation was executed during the summer of 1976. Herbaceous and shrub vegetation were characterized by biomass and cover measurements together with the identification of the three principal species in each vegetation layer. In addition, the influence of the density of the previous conifer stand on the occurrence and abundance of shrub individuals following site preparation and the activity of browsers on both planted coniferous transplants and shrub stems were examined. Results were evaluated in relation to the rate of reoccupancy of the site by herbaceous and shrub vegetation. This was used in an attempt to conceptualize the relative roles of both components of the system in the early stages of succession, and to determine the strategies of these vegetation components as secondary plant succession progresses. The vegetation on a clearcut unit is made up of several small vegetative units as a consequence of the different intensities of the site preparation method used and is, therefore, variable in structure and composition. Findings indicate that early successional trends are characterized by an increasing abundance of both herbaceous and shrub species in proportions related to the particular set of site conditions imposed by the method of site preparation. In the initial stages of succession, microenvironmental factors under the influence of herbaceous species appear to control the establishment of conifers while by the fourth year increasing influence from the sprouting shrubs usurps a controlling influence on further succession. The suppressive effect of coniferous overstory on understory development of shrubs indicates that intense brush recovery is more likely to happen on sites previously supporting conifer stands of low density. Such a trend, although variable, identifies the desirability of high stand densities on brush threat sites. Selective feeding on coniferous seedlings and on brush sprouts by deer and rodents appears to be an important consideration in long term succession. Animal populations are high in habitats conditioned by site preparation; the vegetation following scarification and slash burning appeared especially attractive to browsers while that after spraying appeared attractive to rodents. Over all, composition of perennials shortly after disturbance, especially sprouting woody species, has a major effect on long-term community development. Selective consumption by deer and rodents can delete components of low abundance, such as conifers, during the early stages of succession. Choice of site preparation method can affect both the composition and the density of woody cover and the apparent degree of animal use. Title: Early plant biomass trends following forest site preparation on the Oregon Coast Range Author: Malavasi, Ubirajara Contro The vegetation following forest site preparation was examined in ten clearcut units located in the western Oregon Coast Range. The site preparation techniques used in these units included scarification, slash burning, and chemical spraying. The ages of the clearcut units studied varied from one to nine growing seasons for the scarification treatment, two to ten for the slash burning treatment, and two to six for the spraying treatment. The survey of the vegetation was executed during the summer of 1976. Herbaceous and shrub vegetation were characterized by biomass and cover measurements together with the identification of the three principal species in each vegetation layer. In addition, the influence of the density of the previous conifer stand on the occurrence and abundance of shrub individuals following site preparation and the activity of browsers on both planted coniferous transplants and shrub stems were examined. Results were evaluated in relation to the rate of reoccupancy of the site by herbaceous and shrub vegetation. This was used in an attempt to conceptualize the relative roles of both components of the system in the early stages of succession, and to determine the strategies of these vegetation components as secondary plant succession progresses. The vegetation on a clearcut unit is made up of several small vegetative units as a consequence of the different intensities of the site preparation method used and is, therefore, variable in structure and composition. Findings indicate that early successional trends are characterized by an increasing abundance of both herbaceous and shrub species in proportions related to the particular set of site conditions imposed by the method of site preparation. In the initial stages of succession, microenvironmental factors under the influence of herbaceous species appear to control the establishment of conifers while by the fourth year increasing influence from the sprouting shrubs usurps a controlling influence on further succession. The suppressive effect of coniferous overstory on understory development of shrubs indicates that intense brush recovery is more likely to happen on sites previously supporting conifer stands of low density. Such a trend, although variable, identifies the desirability of high stand densities on brush threat sites. Selective feeding on coniferous seedlings and on brush sprouts by deer and rodents appears to be an important consideration in long term succession. Animal populations are high in habitats conditioned by site preparation; the vegetation following scarification and slash burning appeared especially attractive to browsers while that after spraying appeared attractive to rodents. Over all, composition of perennials shortly after disturbance, especially sprouting woody species, has a major effect on long-term community development. Selective consumption by deer and rodents can delete components of low abundance, such as conifers, during the early stages of succession. Choice of site preparation method can affect both the composition and the density of woody cover and the apparent degree of animal use. Close

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

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

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

• 359. [Article] Industrial engineering in America as a guide for industrial engineering education in Kore

  The purpose of this study is to investigate the direction of future Korean industrial engineering education and to suggest how U.S. experiences can guide Korean developments. The leading indicator concept, ...

  Citation × Citation Citation Abstract Copy Title: Industrial engineering in America as a guide for industrial engineering education in Kore Author: Ro, In Kyu The purpose of this study is to investigate the direction of future Korean industrial engineering education and to suggest how U.S. experiences can guide Korean developments. The leading indicator concept, correlation coefficients are utilized. The following statistical relationships were developed and the following educational and practical industrial engineering trends in the U.S. are surveyed through literature: 1. Statistical relationships between Korean economy and industry during the 1961 - 1970 period and the U.S. experience during the 1948 - 1957 period. 2. Statistical relationships of IE enrollment to seven manufacturing industries in the U.S. during the 1948 - 195 7 period. 3. The trends of industrial engineering curricula in the U. S. from 1958-1959 to 1971-1972. 4. The trends of industrial engineering education and the practices in the U.S. during the 1962 - 1966 period. It is concluded that the U.S. during the 1948 - 19 57 period is a "leading indicator" for economic and industrial developments in Korea during the 1961 - 1970 period. Therefore, unless Korean developments depart radically from historical patterns, the 1962 - 1965 conditions for industrial engineering in the U. S. should suggest what logically to expect in Korea during the 1975 - 1978 period. Based on these conditions, the following suggestions should guide current industrial engineering developments in Korea: 1. Initial efforts should emphasize traditional industrial engineering subjects that are immediately applicable in Korean economy. 2. The curriculum design should make use of the experience of U. S. developments in industrial engineering education which suggest an integration of basic science with engineering subjects and inclusion of humanities and social sciences. 3. After a basic IE program has been established in Korea, more sophisticated mathematical and statistical tools can be added. Revisions must be made to keep the curriculum current. Graduate studies in industrial engineering should not be initiated until production processes in Korean industries become more complex and can benefit from advanced IE techniques. 4. A faculty development program should be implemented. 5. Plans should be developed to show industry what IE's can do and to get support of government and industry for Cooperative programs. 6. Cooperative programs should be started. 7. Staff and educational resources should be improved. 8. Develop IE technicians. 9. Methods for serving small and medium industries should be developed. Many of the obstacles facing the introduction of industrial engineering to Korea can be overcome by actions such as affiliating Korean and U. S. universities, exchanging study teams and consultants, advertising by publications and conferences what can be gained by using IE tools, acquiring IE reference materials and sponsoring IE consultations for small Korean industries. Title: Industrial engineering in America as a guide for industrial engineering education in Kore Author: Ro, In Kyu The purpose of this study is to investigate the direction of future Korean industrial engineering education and to suggest how U.S. experiences can guide Korean developments. The leading indicator concept, correlation coefficients are utilized. The following statistical relationships were developed and the following educational and practical industrial engineering trends in the U.S. are surveyed through literature: 1. Statistical relationships between Korean economy and industry during the 1961 - 1970 period and the U.S. experience during the 1948 - 1957 period. 2. Statistical relationships of IE enrollment to seven manufacturing industries in the U.S. during the 1948 - 195 7 period. 3. The trends of industrial engineering curricula in the U. S. from 1958-1959 to 1971-1972. 4. The trends of industrial engineering education and the practices in the U.S. during the 1962 - 1966 period. It is concluded that the U.S. during the 1948 - 19 57 period is a "leading indicator" for economic and industrial developments in Korea during the 1961 - 1970 period. Therefore, unless Korean developments depart radically from historical patterns, the 1962 - 1965 conditions for industrial engineering in the U. S. should suggest what logically to expect in Korea during the 1975 - 1978 period. Based on these conditions, the following suggestions should guide current industrial engineering developments in Korea: 1. Initial efforts should emphasize traditional industrial engineering subjects that are immediately applicable in Korean economy. 2. The curriculum design should make use of the experience of U. S. developments in industrial engineering education which suggest an integration of basic science with engineering subjects and inclusion of humanities and social sciences. 3. After a basic IE program has been established in Korea, more sophisticated mathematical and statistical tools can be added. Revisions must be made to keep the curriculum current. Graduate studies in industrial engineering should not be initiated until production processes in Korean industries become more complex and can benefit from advanced IE techniques. 4. A faculty development program should be implemented. 5. Plans should be developed to show industry what IE's can do and to get support of government and industry for Cooperative programs. 6. Cooperative programs should be started. 7. Staff and educational resources should be improved. 8. Develop IE technicians. 9. Methods for serving small and medium industries should be developed. Many of the obstacles facing the introduction of industrial engineering to Korea can be overcome by actions such as affiliating Korean and U. S. universities, exchanging study teams and consultants, advertising by publications and conferences what can be gained by using IE tools, acquiring IE reference materials and sponsoring IE consultations for small Korean industries. Close

• 360. [Article] The provenance and trace element signatures of MORB anorthitic plagioclase

  In an attempt to understand the phase equilibria and petrogenesis of MORB anorthitic plagioclase, Cr-spinel commonly hosted within anorthitic plagioclase has been investigated petrographically and compositionally. ...

  Citation × Citation Citation Abstract Copy Title: The provenance and trace element signatures of MORB anorthitic plagioclase Author: Burleigh, Andrew W. In an attempt to understand the phase equilibria and petrogenesis of MORB anorthitic plagioclase, Cr-spinel commonly hosted within anorthitic plagioclase has been investigated petrographically and compositionally. Based on spinel-anorthite relationships from three samples of plagioclase ultra-phyric basalt (PUB; Southeast Indian Ridge, Axial Seamount and West Valley Segment, Juan de Fuca Ridge) our work finds that Cr-spinel hosted within anorthitic megacrysts consistently exhibit rounded, partially dissolved morphologies. In addition, spinel included in anorthitic plagioclase are often accompanied by melt in a composite 2 phase inclusion. Cr-spinel compositionally exhibits collinear negative correlations in Mg# (Mg/Mg+Fe; 0.6-0.73) and Cr# (Cr/Cr+Al; 0.2-0.6), and positive correlations of Cr# and Fe³⁺# (Fe³⁺/ Fe³⁺+Cr+Al; <0.1) with TiO₂ wt% (0.3-0.8). Additionally, all spinel appear to exhibit mantle affinity (Fe³⁺#<0.1; Barnes and Roedder, 2001). Based on historical interpretations of Cr-spinel (Dick and Bullen, 1984), we conclude that Cr-spinel hosted within MORB anorthitic plagioclase preserve melt-mantle reaction signatures. Such reactions, potentially forming dunite, result when ascending low-a[subscript silica] primitive melts interact and consume upper mantle silicates (i.e. clinopyroxene), and include Cr,Al-rich spinel. Thus, both Al and Ca are released into the derivative melt stabilizing anorthitic plagioclase. Given that olivine has never been found in contact with plagioclase >An₈₆, we propose that anorthitic plagioclase precipitates from the derivative liquid prior to olivine. Recently, studies have used the trace element signatures of MORB anorthitic plagioclase as probes of early differentiation processes beneath MOR (Adams et al., 2011; Weinsteiger et al., in review). However, these studies have outlined the need to decipher the geochemical signals of individual anorthitic plagioclase so that population trends may be interpreted. In response, this thesis also reports detailed trace element profiles of individual anorthitic plagioclase crystals and population trends from two samples of PUB (Southeast Indian Ridge [SEIR] sample, Axial Seamount sample). Profiles can be categorized as dominantly stochastic since correlations between trace elements and trace and major elements are largely not found; potentially precluding a role for diffusive re-equilibration. We propose that trace element heterogeneities found within individual crystals reflect the degree of trace element variability present within upper mantle and lower crust conduits. However, by observing population data specific processes may be seen. Similarities in Axial Seamount plagioclase trace elements suggest a relatively uniform source that was evolving largely as a result of plagioclase only fractionation. In contrast, the array of trace element concentrations of SEIR plagioclase positively correlates with major element variations. This suggests a complex process of melt aggregation of increasing percent melts concurrently with anorthitic plagioclase precipitation. Further process related signatures can be derived by viewing plots combining trace and major elements from both samples. In this format, each samples data suggest that similar large scale processes occur in conduits within the upper mantle where these anorthite populations' form. Although plagioclase only fractionation appears to frame the trend, the correlation is diffuse and potentially reflects additional magmatic processes (i.e. AFC, % melt, and melt aggregation). Calculated equilibrium liquids based on Axial Seamount and SEIR plagioclase are considerably depleted relative to their host glass and natural glasses documented to occur near the sampled site. The differentiation processes linking these melt compositions is currently unknown. Title: The provenance and trace element signatures of MORB anorthitic plagioclase Author: Burleigh, Andrew W. In an attempt to understand the phase equilibria and petrogenesis of MORB anorthitic plagioclase, Cr-spinel commonly hosted within anorthitic plagioclase has been investigated petrographically and compositionally. Based on spinel-anorthite relationships from three samples of plagioclase ultra-phyric basalt (PUB; Southeast Indian Ridge, Axial Seamount and West Valley Segment, Juan de Fuca Ridge) our work finds that Cr-spinel hosted within anorthitic megacrysts consistently exhibit rounded, partially dissolved morphologies. In addition, spinel included in anorthitic plagioclase are often accompanied by melt in a composite 2 phase inclusion. Cr-spinel compositionally exhibits collinear negative correlations in Mg# (Mg/Mg+Fe; 0.6-0.73) and Cr# (Cr/Cr+Al; 0.2-0.6), and positive correlations of Cr# and Fe³⁺# (Fe³⁺/ Fe³⁺+Cr+Al; <0.1) with TiO₂ wt% (0.3-0.8). Additionally, all spinel appear to exhibit mantle affinity (Fe³⁺#<0.1; Barnes and Roedder, 2001). Based on historical interpretations of Cr-spinel (Dick and Bullen, 1984), we conclude that Cr-spinel hosted within MORB anorthitic plagioclase preserve melt-mantle reaction signatures. Such reactions, potentially forming dunite, result when ascending low-a[subscript silica] primitive melts interact and consume upper mantle silicates (i.e. clinopyroxene), and include Cr,Al-rich spinel. Thus, both Al and Ca are released into the derivative melt stabilizing anorthitic plagioclase. Given that olivine has never been found in contact with plagioclase >An₈₆, we propose that anorthitic plagioclase precipitates from the derivative liquid prior to olivine. Recently, studies have used the trace element signatures of MORB anorthitic plagioclase as probes of early differentiation processes beneath MOR (Adams et al., 2011; Weinsteiger et al., in review). However, these studies have outlined the need to decipher the geochemical signals of individual anorthitic plagioclase so that population trends may be interpreted. In response, this thesis also reports detailed trace element profiles of individual anorthitic plagioclase crystals and population trends from two samples of PUB (Southeast Indian Ridge [SEIR] sample, Axial Seamount sample). Profiles can be categorized as dominantly stochastic since correlations between trace elements and trace and major elements are largely not found; potentially precluding a role for diffusive re-equilibration. We propose that trace element heterogeneities found within individual crystals reflect the degree of trace element variability present within upper mantle and lower crust conduits. However, by observing population data specific processes may be seen. Similarities in Axial Seamount plagioclase trace elements suggest a relatively uniform source that was evolving largely as a result of plagioclase only fractionation. In contrast, the array of trace element concentrations of SEIR plagioclase positively correlates with major element variations. This suggests a complex process of melt aggregation of increasing percent melts concurrently with anorthitic plagioclase precipitation. Further process related signatures can be derived by viewing plots combining trace and major elements from both samples. In this format, each samples data suggest that similar large scale processes occur in conduits within the upper mantle where these anorthite populations' form. Although plagioclase only fractionation appears to frame the trend, the correlation is diffuse and potentially reflects additional magmatic processes (i.e. AFC, % melt, and melt aggregation). Calculated equilibrium liquids based on Axial Seamount and SEIR plagioclase are considerably depleted relative to their host glass and natural glasses documented to occur near the sampled site. The differentiation processes linking these melt compositions is currently unknown. Close