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• 28751. [Article] Factors that affect U.S.D.A. timber sale layout time in the Pacific Northwest

  The change in emphasis from tractor and highlead logging systems to the advanced logging systems of skyline, balloon, and helicopter has stirred researchers to study the operations of the advanced systems. ...

  Citation × Citation Citation Abstract Copy Title: Factors that affect U.S.D.A. timber sale layout time in the Pacific Northwest Author: Schnare, Jon Keith The change in emphasis from tractor and highlead logging systems to the advanced logging systems of skyline, balloon, and helicopter has stirred researchers to study the operations of the advanced systems. The extra work involved in preparing an area for contract timber removal using advanced logging systems, however, has not been studied. The impacts of the extra time and extra manpower required for this process are large and they are important impacts which need to be taken into consideration during crew work planning. This is difficult to do since the factors which affect crew manhours have not been defined. The objectives of this paper are to determine which factors affect the number of manhours spent on the presale fieldwork portion of preparing a U.S.D.A. Forest Service timber sale for contract; to compare presale field work time on conventional and special-design sales; and to develop a methodology for predicting presale fieldwork time. Previous studies suggest some factors which affect forestry work, but the quantitative changes in production caused by each factor have not been measured. Logging operation research and human engineering studies report that the following factors affect production: underbrush, topography, weather, heat, cold, muscle fatigue, motivation, the work-rest period, tobacco, and alcohol. Motivation is often an overriding factor which outweighs all other considerations. Motivation was not measured in this study, but it was expected to have some effect on the results. Topography, underbrush, and weather were expected to be the most important variables for predicting manhours. Data or presale fieldwork time were collected from 16 districts on eight National Forests in Oregon and Washington, using a form designed to simplify data collection and coding for computer input. The form was a daily work record which could be easily filled out in a few minutes by the field crew. District personnel on each of the 16 districts were personally contacted about cooperating in the study, but they were not pressured to collect data even if they agreed to cooperate. The sample was designed to collect a distribution of data from the coast, eastside, and Cascade areas respectively, but most data collected came from the Cascade area. Activity categories for data collection included layout, traverse, marking,cruising, skyline profile, wildlife related activity, land line retracement, spur road traverse, spur road location, and timber stand examination. The data were separated by activity and by complete units, and were analyzed using a stepwise multiple regression program. Variables found to increase the number of manhours required for presale fieldwork were acres, boundary sinuosity, and silvicultural treatment. The significant variables which reduced manhours were landscape management designation and the distance walked from the vehicle to the unit. These two variables had been expected to increase manhours, but the effect of motivation may have been the cause for the unexpected reverse of sign on the regression coefficients. Special design designation showed no significant effect on manhours except through boundary sinuosity. The regression equations recommended for use in predicting manhours are for the activities of layout using on-the-ground aerial photo-interpretation; traverse using a hand compass, clinometer, and chain; marking of leave trees; cruising by the variable plot method; and for the Cascade area complete units. Nomographs are provided for the solution of these regression equations. Title: Factors that affect U.S.D.A. timber sale layout time in the Pacific Northwest Author: Schnare, Jon Keith The change in emphasis from tractor and highlead logging systems to the advanced logging systems of skyline, balloon, and helicopter has stirred researchers to study the operations of the advanced systems. The extra work involved in preparing an area for contract timber removal using advanced logging systems, however, has not been studied. The impacts of the extra time and extra manpower required for this process are large and they are important impacts which need to be taken into consideration during crew work planning. This is difficult to do since the factors which affect crew manhours have not been defined. The objectives of this paper are to determine which factors affect the number of manhours spent on the presale fieldwork portion of preparing a U.S.D.A. Forest Service timber sale for contract; to compare presale field work time on conventional and special-design sales; and to develop a methodology for predicting presale fieldwork time. Previous studies suggest some factors which affect forestry work, but the quantitative changes in production caused by each factor have not been measured. Logging operation research and human engineering studies report that the following factors affect production: underbrush, topography, weather, heat, cold, muscle fatigue, motivation, the work-rest period, tobacco, and alcohol. Motivation is often an overriding factor which outweighs all other considerations. Motivation was not measured in this study, but it was expected to have some effect on the results. Topography, underbrush, and weather were expected to be the most important variables for predicting manhours. Data or presale fieldwork time were collected from 16 districts on eight National Forests in Oregon and Washington, using a form designed to simplify data collection and coding for computer input. The form was a daily work record which could be easily filled out in a few minutes by the field crew. District personnel on each of the 16 districts were personally contacted about cooperating in the study, but they were not pressured to collect data even if they agreed to cooperate. The sample was designed to collect a distribution of data from the coast, eastside, and Cascade areas respectively, but most data collected came from the Cascade area. Activity categories for data collection included layout, traverse, marking,cruising, skyline profile, wildlife related activity, land line retracement, spur road traverse, spur road location, and timber stand examination. The data were separated by activity and by complete units, and were analyzed using a stepwise multiple regression program. Variables found to increase the number of manhours required for presale fieldwork were acres, boundary sinuosity, and silvicultural treatment. The significant variables which reduced manhours were landscape management designation and the distance walked from the vehicle to the unit. These two variables had been expected to increase manhours, but the effect of motivation may have been the cause for the unexpected reverse of sign on the regression coefficients. Special design designation showed no significant effect on manhours except through boundary sinuosity. The regression equations recommended for use in predicting manhours are for the activities of layout using on-the-ground aerial photo-interpretation; traverse using a hand compass, clinometer, and chain; marking of leave trees; cruising by the variable plot method; and for the Cascade area complete units. Nomographs are provided for the solution of these regression equations. Close

• 28752. [Article] Elevational differences in UV-B response by the long-toed salamander (Ambystoma macrodactylum)

  Global amphibian declines have been attributed to numerous and often synergistic causes, such as invasive species, pathogens, and ultraviolet-B (UV-B) radiation. The effects of these stressors are context ...

  Citation × Citation Citation Abstract Copy Title: Elevational differences in UV-B response by the long-toed salamander (Ambystoma macrodactylum) Author: Thurman, Lindsey L. Global amphibian declines have been attributed to numerous and often synergistic causes, such as invasive species, pathogens, and ultraviolet-B (UV-B) radiation. The effects of these stressors are context dependent and can vary with location, species, and populations. As sensitivity to UV-B has shown inconsistencies across amphibian taxa, it can be expected that variation also occurs between populations of a single species. High elevation populations of the long-toed salamander (Ambystoma macrodactylum) face exponentially higher UV-B radiation levels relative to low elevation populations and these levels are predicted to increase in conjunction with continued ozone depletion. We hypothesized that breeding long-toed salamander females at high elevations have modified oviposition behavior to better protect embryos from UV-B induced damage. In addition, we hypothesized that long-toed salamander embryos at high elevation would exhibit elevated photolyase activity, a photo-reactivating enzyme that repairs UV-B radiation-induced damage to DNA. We predicted that this behavioral defense strategy would be employed together with an elevated physiological response as a correlated defense response to increased levels of UV-B radiation in high elevation populations. We surveyed high and low elevation long-toed salamander breeding sites throughout Oregon to quantify oviposition site characteristics and associated UV-B profiles. We simultaneously collected embryos for quantification of photolyase activity in a bacterial transformation assay. We found significant differences in oviposition behavior across elevations, with high elevation breeding females ovipositing in deeper water and using UV-B protective refugia. Oviposition sites at low elevations, however, were most often found in UV-B exposed microhabitats located at the surface of the water. This population difference in oviposition behavior resulted in a standardization of UV-B and temperature conditions for long-toed salamander embryos across elevation. In contrast, we found no population differentiation in photolyase activity between high and low elevation breeding sites. This indicates that behavioral selection for UV-B protected oviposition substrates may either be negating the need for increased photolyase activity in long-toed salamander embryos, or that populations lack the capacity to adapt a heightened physiological response to UV-B at high elevations. Together, these results show how trade-offs in physiology and behavior are a unique adaptation to a significant environmental stressor. Further research into the susceptibility of amphibian species to changing environmental conditions may help to demonstrate the effectiveness of correlated trait responses and plasticity in behavior, and species persistence under changing climate regimes. Title: Elevational differences in UV-B response by the long-toed salamander (Ambystoma macrodactylum) Author: Thurman, Lindsey L. Global amphibian declines have been attributed to numerous and often synergistic causes, such as invasive species, pathogens, and ultraviolet-B (UV-B) radiation. The effects of these stressors are context dependent and can vary with location, species, and populations. As sensitivity to UV-B has shown inconsistencies across amphibian taxa, it can be expected that variation also occurs between populations of a single species. High elevation populations of the long-toed salamander (Ambystoma macrodactylum) face exponentially higher UV-B radiation levels relative to low elevation populations and these levels are predicted to increase in conjunction with continued ozone depletion. We hypothesized that breeding long-toed salamander females at high elevations have modified oviposition behavior to better protect embryos from UV-B induced damage. In addition, we hypothesized that long-toed salamander embryos at high elevation would exhibit elevated photolyase activity, a photo-reactivating enzyme that repairs UV-B radiation-induced damage to DNA. We predicted that this behavioral defense strategy would be employed together with an elevated physiological response as a correlated defense response to increased levels of UV-B radiation in high elevation populations. We surveyed high and low elevation long-toed salamander breeding sites throughout Oregon to quantify oviposition site characteristics and associated UV-B profiles. We simultaneously collected embryos for quantification of photolyase activity in a bacterial transformation assay. We found significant differences in oviposition behavior across elevations, with high elevation breeding females ovipositing in deeper water and using UV-B protective refugia. Oviposition sites at low elevations, however, were most often found in UV-B exposed microhabitats located at the surface of the water. This population difference in oviposition behavior resulted in a standardization of UV-B and temperature conditions for long-toed salamander embryos across elevation. In contrast, we found no population differentiation in photolyase activity between high and low elevation breeding sites. This indicates that behavioral selection for UV-B protected oviposition substrates may either be negating the need for increased photolyase activity in long-toed salamander embryos, or that populations lack the capacity to adapt a heightened physiological response to UV-B at high elevations. Together, these results show how trade-offs in physiology and behavior are a unique adaptation to a significant environmental stressor. Further research into the susceptibility of amphibian species to changing environmental conditions may help to demonstrate the effectiveness of correlated trait responses and plasticity in behavior, and species persistence under changing climate regimes. Close

• 28753. [Article] Behavioral and electrophysiological evidence for the mechanisms involved in the detection of ionizing radiations by the crayfish Pacifastacus trowbridgii

  The light-adapted crayfish, Pacifastacus trowbridgii (Stimpson, 1957), displayed a behavioral response to exposure to 300 kV x-rays at exposure rates of 10 to 30 R/s. Within this range, the proportion of ...

  Citation × Citation Citation Abstract Copy Title: Behavioral and electrophysiological evidence for the mechanisms involved in the detection of ionizing radiations by the crayfish Pacifastacus trowbridgii Author: Rodriguez, Adrian The light-adapted crayfish, Pacifastacus trowbridgii (Stimpson, 1957), displayed a behavioral response to exposure to 300 kV x-rays at exposure rates of 10 to 30 R/s. Within this range, the proportion of subjects that responded increased with an increase in exposure rate. The response latency was inversely proportional to the exposure rate. Ophthalmectomized animals exhibited a similar response with a significantly shorter latency than the intact animals at the same exposure rate (30 R/s). Partial body exposure of ophthalmectomized animals also elicited a behavioral response and indicated that a radiation-sensitive receptor was located in the abdomen. X-ray exposure of the dark-adapted compound eye evoked an electroretinogram (ERG) that was similar to the light evoked ERG. The x-ray evoked ERG amplitude was found to be dependent on total exposure for stimulus durations of 300 ms or less. With stimulus durations greater than 300 ms, the ERG amplitude increased in relation to the logarithm of the exposure rate. Similar responses with light, indicated that the mechanism of interaction may be the same for x-rays. The time course for maximal dark - adaptation, after a 500 ms exposure to 3.85 ft-c of light, was comparable for both x-ray and light exposure (9 min). Differences observed in ERG amplitude between the light and x-ray evoked responses during the initial recovery period can be attributed to absorption of light by migrating accessory pigments or by differential interaction of light with photosensitive pigments in the eye. X-ray exposure (10 to 35 R/s) of the medial branch of the antennule and the cheliped of the first walking leg did not yield any significant chemoreceptor responses as judged by electrophysiological tests. The presence of chemoreceptors was indicated by responses elicited after administration of glutamic acid, glycine, and fish extract. X-irradiation of the dark-adapted sixth abdominal ganglion in both isolated and in vivo preparations elicited similar increases in neural impulse frequency. Significant increases occurred after ten seconds of exposure with an exposure rate of 25 R/s. The response latency decreased to five seconds with 30 and 35 R/s. It was observed that the spike potentials evoked with x-rays were similar to those evoked by light (75-100 microvolts). There was, however, a supplemental increase in spike potentials of lower amplitude (40-50 microvolts) during x-irradiation that was not observed with light. This indicated that neural elements other than the photo sensitive neurons of the ganglion were activated. It appears likely that the behavioral response in crayfish, subjected to abdomen-only exposure may be instigated by x-ray excitation of the sixth ganglion. Title: Behavioral and electrophysiological evidence for the mechanisms involved in the detection of ionizing radiations by the crayfish Pacifastacus trowbridgii Author: Rodriguez, Adrian The light-adapted crayfish, Pacifastacus trowbridgii (Stimpson, 1957), displayed a behavioral response to exposure to 300 kV x-rays at exposure rates of 10 to 30 R/s. Within this range, the proportion of subjects that responded increased with an increase in exposure rate. The response latency was inversely proportional to the exposure rate. Ophthalmectomized animals exhibited a similar response with a significantly shorter latency than the intact animals at the same exposure rate (30 R/s). Partial body exposure of ophthalmectomized animals also elicited a behavioral response and indicated that a radiation-sensitive receptor was located in the abdomen. X-ray exposure of the dark-adapted compound eye evoked an electroretinogram (ERG) that was similar to the light evoked ERG. The x-ray evoked ERG amplitude was found to be dependent on total exposure for stimulus durations of 300 ms or less. With stimulus durations greater than 300 ms, the ERG amplitude increased in relation to the logarithm of the exposure rate. Similar responses with light, indicated that the mechanism of interaction may be the same for x-rays. The time course for maximal dark - adaptation, after a 500 ms exposure to 3.85 ft-c of light, was comparable for both x-ray and light exposure (9 min). Differences observed in ERG amplitude between the light and x-ray evoked responses during the initial recovery period can be attributed to absorption of light by migrating accessory pigments or by differential interaction of light with photosensitive pigments in the eye. X-ray exposure (10 to 35 R/s) of the medial branch of the antennule and the cheliped of the first walking leg did not yield any significant chemoreceptor responses as judged by electrophysiological tests. The presence of chemoreceptors was indicated by responses elicited after administration of glutamic acid, glycine, and fish extract. X-irradiation of the dark-adapted sixth abdominal ganglion in both isolated and in vivo preparations elicited similar increases in neural impulse frequency. Significant increases occurred after ten seconds of exposure with an exposure rate of 25 R/s. The response latency decreased to five seconds with 30 and 35 R/s. It was observed that the spike potentials evoked with x-rays were similar to those evoked by light (75-100 microvolts). There was, however, a supplemental increase in spike potentials of lower amplitude (40-50 microvolts) during x-irradiation that was not observed with light. This indicated that neural elements other than the photo sensitive neurons of the ganglion were activated. It appears likely that the behavioral response in crayfish, subjected to abdomen-only exposure may be instigated by x-ray excitation of the sixth ganglion. Close

• 28754. [Article] Man and the land : an ecological history of fire and grazing on eastern Oregon rangelands

  Ecological and historical information are combined in examining the environmental influence of fire and grazing on rangelands in eastern Oregon through time. Competitive relationships between herbaceous ...

  Citation × Citation Citation Abstract Copy Title: Man and the land : an ecological history of fire and grazing on eastern Oregon rangelands Author: Shinn, Dean Allison Ecological and historical information are combined in examining the environmental influence of fire and grazing on rangelands in eastern Oregon through time. Competitive relationships between herbaceous and woody flora in the northern Great Basin are discussed, focusing broadly on the shrubsteppe regions 'of Franklin and Dyrness (1973) but with special reference to the Artemisia/Agropyron association. Impacts of native and domestic grazing animals and of cultural burning are traced from the distant past into recent history. During the Pleistocene Epoch North America supported a wide diversity of large mammals. Toward the end of the Pleistocene, many of these fauna became extinct, perhaps as a result of post-glacial climatic change, perhaps also under the influence of incoming primitive hunting cultures and their broadcast burning practices. Some question exists about the intensity of native grazing in the northern Great Basin during the last few thousand years. Actual levels of bison populations and the duration of their residence in the study area have not been determined. The character of indigenous vegetations, however, indicates that native grazing was relatively light for an extended period primevally. Twenty-four references to native cultural burning at the time of European contact were found in historical journals. Though the antiquity of these customs is uncertain, an analysis of Native American fire myths demonstrates the depth of native cultural perceptions of the relationship between man and fire, and supports the likelihood that fire was used primevally in the northern Great Basin as it was used by aboriginal peoples elsewhere in North America. With the influx of European culture during the 19th century, misapprehensions about fire among whites distorted the influence of native cultural burning. Exotic flora and fauna were introduced, and ecosystems began to change. Large herds of livestock depleted native herbaceous populations. Early irresponsible burning by whites became associated with declining rangeland resources, and efforts toward total fire suppression became incorporated in developing conservation policies. Native woody flora and exotics began to invade open rangeland communities. Climatic flux during the period of European settlement in the northern Great Basin may have exacerbated the impacts of intensified grazing and elimination of burning. Early photographs of rangelands in east-central Oregon were gathered; their dates range from 1880 to the early 1930's. Sites represented in these pictures were re-photographed in 1976. Photo-set comparisons show expansion of western juniper (Juniperus occidentalis) populations into rangeland ecosystems, demonstrating the consequences of cultural disturbances during the last 150 to 200 years. Title: Man and the land : an ecological history of fire and grazing on eastern Oregon rangelands Author: Shinn, Dean Allison Ecological and historical information are combined in examining the environmental influence of fire and grazing on rangelands in eastern Oregon through time. Competitive relationships between herbaceous and woody flora in the northern Great Basin are discussed, focusing broadly on the shrubsteppe regions 'of Franklin and Dyrness (1973) but with special reference to the Artemisia/Agropyron association. Impacts of native and domestic grazing animals and of cultural burning are traced from the distant past into recent history. During the Pleistocene Epoch North America supported a wide diversity of large mammals. Toward the end of the Pleistocene, many of these fauna became extinct, perhaps as a result of post-glacial climatic change, perhaps also under the influence of incoming primitive hunting cultures and their broadcast burning practices. Some question exists about the intensity of native grazing in the northern Great Basin during the last few thousand years. Actual levels of bison populations and the duration of their residence in the study area have not been determined. The character of indigenous vegetations, however, indicates that native grazing was relatively light for an extended period primevally. Twenty-four references to native cultural burning at the time of European contact were found in historical journals. Though the antiquity of these customs is uncertain, an analysis of Native American fire myths demonstrates the depth of native cultural perceptions of the relationship between man and fire, and supports the likelihood that fire was used primevally in the northern Great Basin as it was used by aboriginal peoples elsewhere in North America. With the influx of European culture during the 19th century, misapprehensions about fire among whites distorted the influence of native cultural burning. Exotic flora and fauna were introduced, and ecosystems began to change. Large herds of livestock depleted native herbaceous populations. Early irresponsible burning by whites became associated with declining rangeland resources, and efforts toward total fire suppression became incorporated in developing conservation policies. Native woody flora and exotics began to invade open rangeland communities. Climatic flux during the period of European settlement in the northern Great Basin may have exacerbated the impacts of intensified grazing and elimination of burning. Early photographs of rangelands in east-central Oregon were gathered; their dates range from 1880 to the early 1930's. Sites represented in these pictures were re-photographed in 1976. Photo-set comparisons show expansion of western juniper (Juniperus occidentalis) populations into rangeland ecosystems, demonstrating the consequences of cultural disturbances during the last 150 to 200 years. Close

• 28755. [Article] A photoactivable microfluidic device for heavy metal ion extraction

  The development of microfluidic devices for heavy metal extraction is presented in this dissertation. Various research areas, covering subjects from photochromic compound syntheses to microchip fabrication ...

  Citation × Citation Citation Abstract Copy Title: A photoactivable microfluidic device for heavy metal ion extraction Author: Nammoonnoy, Jintana The development of microfluidic devices for heavy metal extraction is presented in this dissertation. Various research areas, covering subjects from photochromic compound syntheses to microchip fabrication techniques are explored to develop microfluidic devices capable of extracting heavy metal ions from drinking water. Through integration of the beneficial characteristics of both microfluidic devices and photochromic dyes, a simple and innovative microchip configured as a photoactivable extraction system for metal ion accumulation and release can be realized. The initial research focused on the utilization of photochromic compounds namely spiropyrans, as chelators for heavy metal extraction. Spiropyrans are organic photochromic compounds that have been widely studied. Upon irradiation with UV or visible light, spiropyrans isomerize between the closed and open forms, in which the open form is comparatively more polar. Metal ions can influence this isomerization process by associating with the open form through the electron-rich oxygen atom. In contrast, visible light produces a high concentration of the closed form, and thus hinders metal-binding. Spiropyrans, therefore, show great potential as photo-reversible metal-complexation agents. The spiropyran derivatives were synthesized and immobilized on solid supports including polymeric resins and poly(methylmethacrylate) (PMMA) microchips. Metal ion uptake can be triggered using UV light and subsequently reversed on demand by shining green light on the colored complex, which regenerates the inactive spiropyran form resulting in the release of metal ions. The use of light to trigger the chelator offers unique opportunities. The work continued with the development of microfluidic fabrication for creating versatile, solvent-compatible microfluidic devices through surface modification. There are challenges associated with the use of polymeric based microfluidic devices, particularly in surface modification steps, as solvents can embrittle thermoplastics that resulting in microcracking. To overcome this limitation, we explored the possibility of fabricating extremely robust microfluidic devices entirely from fluorocarbon and glass materials. The work demonstrated a new fabrication technique based on a chemically activated poly(tetrafluoro ethylene) (PTFE) sheet sandwiched between chemically activated glass substrates. The PTFE microchannels can be fabricated in minutes using a cutting plotter to create microchannels. The possibility of glass to PTFE makes this method applicable in a wide range of applications. Title: A photoactivable microfluidic device for heavy metal ion extraction Author: Nammoonnoy, Jintana The development of microfluidic devices for heavy metal extraction is presented in this dissertation. Various research areas, covering subjects from photochromic compound syntheses to microchip fabrication techniques are explored to develop microfluidic devices capable of extracting heavy metal ions from drinking water. Through integration of the beneficial characteristics of both microfluidic devices and photochromic dyes, a simple and innovative microchip configured as a photoactivable extraction system for metal ion accumulation and release can be realized. The initial research focused on the utilization of photochromic compounds namely spiropyrans, as chelators for heavy metal extraction. Spiropyrans are organic photochromic compounds that have been widely studied. Upon irradiation with UV or visible light, spiropyrans isomerize between the closed and open forms, in which the open form is comparatively more polar. Metal ions can influence this isomerization process by associating with the open form through the electron-rich oxygen atom. In contrast, visible light produces a high concentration of the closed form, and thus hinders metal-binding. Spiropyrans, therefore, show great potential as photo-reversible metal-complexation agents. The spiropyran derivatives were synthesized and immobilized on solid supports including polymeric resins and poly(methylmethacrylate) (PMMA) microchips. Metal ion uptake can be triggered using UV light and subsequently reversed on demand by shining green light on the colored complex, which regenerates the inactive spiropyran form resulting in the release of metal ions. The use of light to trigger the chelator offers unique opportunities. The work continued with the development of microfluidic fabrication for creating versatile, solvent-compatible microfluidic devices through surface modification. There are challenges associated with the use of polymeric based microfluidic devices, particularly in surface modification steps, as solvents can embrittle thermoplastics that resulting in microcracking. To overcome this limitation, we explored the possibility of fabricating extremely robust microfluidic devices entirely from fluorocarbon and glass materials. The work demonstrated a new fabrication technique based on a chemically activated poly(tetrafluoro ethylene) (PTFE) sheet sandwiched between chemically activated glass substrates. The PTFE microchannels can be fabricated in minutes using a cutting plotter to create microchannels. The possibility of glass to PTFE makes this method applicable in a wide range of applications. Close

• 28756. [Article] Riparian cover changes associated with flow regulation and bank stabilization along the Upper Willamette River in Oregon between 1939 and 1996

  This study investigates riparian cover change between 1939 and 1996 utilizing aerial photography, bank conditions and stream gauge data. Three sites under 1.0 km2, along a 10- km reach north of Harrisburg, ...

  Citation × Citation Citation Abstract Copy Title: Riparian cover changes associated with flow regulation and bank stabilization along the Upper Willamette River in Oregon between 1939 and 1996 Author: Gutowsky, Sharon L. This study investigates riparian cover change between 1939 and 1996 utilizing aerial photography, bank conditions and stream gauge data. Three sites under 1.0 km2, along a 10- km reach north of Harrisburg, Oregon, were evaluated. The cover classification scheme included 18 classes composed of 3 canopy densities and 8 structural categories: water, bare gravel bars, herbaceous, shrub, small trees, medium trees, closed trees, and agricultural fields. Net cover changes and shifts between classes were analyzed for each site as a whole and as terrestrial vs. fluvial changes. Terrestrial changes (i.e. areas unaffected by channel movement) were discriminated from fluvial changes (i.e. areas where a channel migrated out, in or both) by inspection of 14 air photo coverages between 1939 and 1996. Over 75% of each site experienced net cover change between categories of water, bare, cleared land, low vegetation, open-canopy trees, and closed-canopy trees. Water cover composed over half the area that remained the same. Net progressive structural change (i.e. an increase in cover maturity, e.g. bare changing to trees) exceeded or equaled net regressive structural change at each site. Progressive structural change was only slightly favored in fluvial areas, while terrestrial areas favored progression 4 to 1 at each site. Bare ground decreased by 35%, 65% and 90%, while forest cover increased by 10%, 50% and 150% at the three study sites. The only areas of non-forest cover remaining in 1996 existed on land disturbed by the channel since 1939. The maturation of structural cover was associated with decreases in channel dynamics and fluvial disturbance between 1939 and 1996. Channel migration affected 50% to 70% of each study area during this period, but most shifts occurred before 1956. Sixtyeight percent of the revetments present in 1996 were established by 1956. These revetments hardened portions of all outer bends along the study reach, limiting lateral channel migration. Upstream dams held 42% of the 1996 storage by 1956, which reduced peak flows. Title: Riparian cover changes associated with flow regulation and bank stabilization along the Upper Willamette River in Oregon between 1939 and 1996 Author: Gutowsky, Sharon L. This study investigates riparian cover change between 1939 and 1996 utilizing aerial photography, bank conditions and stream gauge data. Three sites under 1.0 km2, along a 10- km reach north of Harrisburg, Oregon, were evaluated. The cover classification scheme included 18 classes composed of 3 canopy densities and 8 structural categories: water, bare gravel bars, herbaceous, shrub, small trees, medium trees, closed trees, and agricultural fields. Net cover changes and shifts between classes were analyzed for each site as a whole and as terrestrial vs. fluvial changes. Terrestrial changes (i.e. areas unaffected by channel movement) were discriminated from fluvial changes (i.e. areas where a channel migrated out, in or both) by inspection of 14 air photo coverages between 1939 and 1996. Over 75% of each site experienced net cover change between categories of water, bare, cleared land, low vegetation, open-canopy trees, and closed-canopy trees. Water cover composed over half the area that remained the same. Net progressive structural change (i.e. an increase in cover maturity, e.g. bare changing to trees) exceeded or equaled net regressive structural change at each site. Progressive structural change was only slightly favored in fluvial areas, while terrestrial areas favored progression 4 to 1 at each site. Bare ground decreased by 35%, 65% and 90%, while forest cover increased by 10%, 50% and 150% at the three study sites. The only areas of non-forest cover remaining in 1996 existed on land disturbed by the channel since 1939. The maturation of structural cover was associated with decreases in channel dynamics and fluvial disturbance between 1939 and 1996. Channel migration affected 50% to 70% of each study area during this period, but most shifts occurred before 1956. Sixtyeight percent of the revetments present in 1996 were established by 1956. These revetments hardened portions of all outer bends along the study reach, limiting lateral channel migration. Upstream dams held 42% of the 1996 storage by 1956, which reduced peak flows. Close

• 28757. [Article] Large woody debris and channel morphology of undisturbed streams in southeast Alaska

  The characteristics and interactions of the riparian stand, large woody debris (LWD), and channel morphology were examined on five undisturbed, low gradient streams in southeast Alaska. One first-, two ...

  Citation × Citation Citation Abstract Copy Title: Large woody debris and channel morphology of undisturbed streams in southeast Alaska Author: Robison, E. George The characteristics and interactions of the riparian stand, large woody debris (LWD), and channel morphology were examined on five undisturbed, low gradient streams in southeast Alaska. One first-, two second-, one third-, and one fourth-order streams were studied. Stream morphology variables were measured systematically at fixed intervals of three to ten feet depending on stream size: 50-foot intervals were used for riparian forest measurements. The percentage of alder comprising the riparian forest increased with stream size. The first- and second-order streams had alder comprising approximately 8% of the total basal area whereas, the fourth-order stream had 25 Likewise, the percentage of LWD pieces consisting of alder increased from 129 in the two smallest first and second-order streams to 319 in the fourth-order stream. These findings, along with inspection of air photos indicate a alternating 1'one sided" alder corridor exists along the largest stream. The proportion of large woody debris pieces with rootwads in the channel increased from 2 and 6% in the two smallest first- and second-order streams to 32° in the fourth-order stream indicating the largest stream has recruited LWD from bank cutting and/or lateral channel migration. LWD oriented perpendicular (900) to general stream flow was relatively frequent for all streams. No significant (alpha=0.05) linear relationship was found (r2<O.05) between piece length and orientation to flow. Channel morphology changed with stream size. For example, the length of stream with side channels and/or braided reaches increased from 1% in the first-order stream to 416 of stream length in the fourth-order stream. The overall percentage of pools averaged 579 and showed no changes with changes in stream size. However, the relative proportions of individual pool "morphological types" and "causal elements" did change with stream size. "Underf low pools" comprised less than 10% of the morphological types in the first-, second-, and third-order streams but increased to 17% in the fourth-order stream. Autocorrelations of the spatial distributions of stream morphological variables (i.e., depth and width) indicated that the streams are influenced by a wide variety of interacting factors and processes. Thus channel dimensions are characterized by high variability and an absence of "memory" or repeatable" components. A positive linear relationship (alpha<O.O1, r2=O.23) was found between LWD volume and the standard deviation of bankfull width. No such relationships were found for other stream morphological variables including thalweg depth, low-flow width, cross-sectional area, and width depth ratio, indicating other variables besides wood volume present are influencing variability in stream morphology, or that the effects of large woody debris upon channel morphology is not easily expressed by linear regression techniques. Autocorrelations and frequency histograms of an upstream forested section, with instream LWD, and a downstream meadow section with no LWD, noncohesive soils and tidal effects, show that the meadow section had greater "memory" and less diversity in "morphological types" and "pool causal elements." These results provide a quantitative assessment of several stream morphology variables for first- through fourth-order streams in southeast Alaska. Further research is needed to compare these results for undisturbed streams with streams influenced by management activities. Title: Large woody debris and channel morphology of undisturbed streams in southeast Alaska Author: Robison, E. George The characteristics and interactions of the riparian stand, large woody debris (LWD), and channel morphology were examined on five undisturbed, low gradient streams in southeast Alaska. One first-, two second-, one third-, and one fourth-order streams were studied. Stream morphology variables were measured systematically at fixed intervals of three to ten feet depending on stream size: 50-foot intervals were used for riparian forest measurements. The percentage of alder comprising the riparian forest increased with stream size. The first- and second-order streams had alder comprising approximately 8% of the total basal area whereas, the fourth-order stream had 25 Likewise, the percentage of LWD pieces consisting of alder increased from 129 in the two smallest first and second-order streams to 319 in the fourth-order stream. These findings, along with inspection of air photos indicate a alternating 1'one sided" alder corridor exists along the largest stream. The proportion of large woody debris pieces with rootwads in the channel increased from 2 and 6% in the two smallest first- and second-order streams to 32° in the fourth-order stream indicating the largest stream has recruited LWD from bank cutting and/or lateral channel migration. LWD oriented perpendicular (900) to general stream flow was relatively frequent for all streams. No significant (alpha=0.05) linear relationship was found (r2<O.05) between piece length and orientation to flow. Channel morphology changed with stream size. For example, the length of stream with side channels and/or braided reaches increased from 1% in the first-order stream to 416 of stream length in the fourth-order stream. The overall percentage of pools averaged 579 and showed no changes with changes in stream size. However, the relative proportions of individual pool "morphological types" and "causal elements" did change with stream size. "Underf low pools" comprised less than 10% of the morphological types in the first-, second-, and third-order streams but increased to 17% in the fourth-order stream. Autocorrelations of the spatial distributions of stream morphological variables (i.e., depth and width) indicated that the streams are influenced by a wide variety of interacting factors and processes. Thus channel dimensions are characterized by high variability and an absence of "memory" or repeatable" components. A positive linear relationship (alpha<O.O1, r2=O.23) was found between LWD volume and the standard deviation of bankfull width. No such relationships were found for other stream morphological variables including thalweg depth, low-flow width, cross-sectional area, and width depth ratio, indicating other variables besides wood volume present are influencing variability in stream morphology, or that the effects of large woody debris upon channel morphology is not easily expressed by linear regression techniques. Autocorrelations and frequency histograms of an upstream forested section, with instream LWD, and a downstream meadow section with no LWD, noncohesive soils and tidal effects, show that the meadow section had greater "memory" and less diversity in "morphological types" and "pool causal elements." These results provide a quantitative assessment of several stream morphology variables for first- through fourth-order streams in southeast Alaska. Further research is needed to compare these results for undisturbed streams with streams influenced by management activities. Close

• 28758. [Article] The effects of ultraviolet irradiation on the photosynthetic apparatus

  The effects of ultraviolet (UV) irradiation on photosynthesis and various partial reactions involving the individual photoreactions of photosynthesis were examined. These reactions included photo-reduction ...

  Citation × Citation Citation Abstract Copy Title: The effects of ultraviolet irradiation on the photosynthetic apparatus Author: Mantai, Kenneth Edward The effects of ultraviolet (UV) irradiation on photosynthesis and various partial reactions involving the individual photoreactions of photosynthesis were examined. These reactions included photo-reduction in adapted green algae, Hill reaction, cyclic photophosphorylation, the 520 nm absorbance change and variable-yield fluorescence. The reactions were measured in spinach chloroplasts and isolated chloroplasts or whole cells of green and blue-green algae. Experiments showing that all system II requiring reactions, as well as photoreduction and cyclic photophosphorylation (which require only system I) were equally inhibited suggested that the site of the UV inhibition was at some point in the electron transport chain near system II. Ascorbate-DCIP mediated reduction of NADP was not affected. A peak in the action spectrum for UV inhibition at 250 nm and an apparent decrease in the plastoquinone (PQ) content of chloroplasts after irradiation suggested that PQ was the locus of the inhibition. However, experiments in which pure, unirradiated PQ was added to irradiated chloroplasts did not restore photochemical activity. In addition, examination of whole cell systems, using various algae, revealed that when photosynthetic activity had been totally abolished, only about 40% of the endogenous PQ had been destroyed. Experiments comparing the effects of petroleum ether extraction of the PQ from lyophilized chloroplasts versus UV irradiation of chloroplasts revealed striking differences. From this type of data it was concluded that destruction of PQ was not the major cause of the UV inhibition. The effects of UV irradiation on the 520 nm absorbance change were also examined. It was found that the system II (DCMU sensitive) portion of the absorbance change was inhibited at a rate parallel to the inhibition of photosynthesis. The system I (DCMU insensitive) portion was also inhibited, but required two to three times the amount of irradiation. Experiments to compare the rate of inhibition of the system I portion of the 520 nm absorbance change with PQ destruction did not reveal any apparent positive correlation. Periods of irradiation sufficient to abolish totally the system I portion of the absorbance change had no effect on the ability of chloroplasts isolated from this material to reduce NADP with the ascorbate-DCIP couple. Extraction of the PQ from chloroplasts abolished both portions of the 520 nm absorbance change, indicating that PQ is required for the change but is not the site of the UV inhibition. Carotenoid, lipid and protein content and complement in irradiated and unirradiated chloroplasts and cells were also compared. In no case was any major alteration noted. Measurements were made of the effects of UV irradiation on the variable-yield fluorescence of isolated chloroplasts and whole cells. It was expected that as photosynthetic activity decreased the variable-yield fluorescence would increase until the maximum attainable yield was reached when photosynthetic activity had been totally abolished. Surprisingly, it was found that the variable-yield fluorescence decreased after UV irradiation and, more important, the maximum attainable yield also decreased. This was interpreted as indicating that the fluorescence emitter, the system II trapping center, was destroyed. Considering all of the results discussed above, it seems likely that UV irradiation disrupts a physical entity consisting of the system II trapping center, the initial electron acceptor from system II, and at least one component beyond the site of DCMU inhibition. This interpretation further suggests that system II consists of a physical unit containing several components of the electron transport chain. Title: The effects of ultraviolet irradiation on the photosynthetic apparatus Author: Mantai, Kenneth Edward The effects of ultraviolet (UV) irradiation on photosynthesis and various partial reactions involving the individual photoreactions of photosynthesis were examined. These reactions included photo-reduction in adapted green algae, Hill reaction, cyclic photophosphorylation, the 520 nm absorbance change and variable-yield fluorescence. The reactions were measured in spinach chloroplasts and isolated chloroplasts or whole cells of green and blue-green algae. Experiments showing that all system II requiring reactions, as well as photoreduction and cyclic photophosphorylation (which require only system I) were equally inhibited suggested that the site of the UV inhibition was at some point in the electron transport chain near system II. Ascorbate-DCIP mediated reduction of NADP was not affected. A peak in the action spectrum for UV inhibition at 250 nm and an apparent decrease in the plastoquinone (PQ) content of chloroplasts after irradiation suggested that PQ was the locus of the inhibition. However, experiments in which pure, unirradiated PQ was added to irradiated chloroplasts did not restore photochemical activity. In addition, examination of whole cell systems, using various algae, revealed that when photosynthetic activity had been totally abolished, only about 40% of the endogenous PQ had been destroyed. Experiments comparing the effects of petroleum ether extraction of the PQ from lyophilized chloroplasts versus UV irradiation of chloroplasts revealed striking differences. From this type of data it was concluded that destruction of PQ was not the major cause of the UV inhibition. The effects of UV irradiation on the 520 nm absorbance change were also examined. It was found that the system II (DCMU sensitive) portion of the absorbance change was inhibited at a rate parallel to the inhibition of photosynthesis. The system I (DCMU insensitive) portion was also inhibited, but required two to three times the amount of irradiation. Experiments to compare the rate of inhibition of the system I portion of the 520 nm absorbance change with PQ destruction did not reveal any apparent positive correlation. Periods of irradiation sufficient to abolish totally the system I portion of the absorbance change had no effect on the ability of chloroplasts isolated from this material to reduce NADP with the ascorbate-DCIP couple. Extraction of the PQ from chloroplasts abolished both portions of the 520 nm absorbance change, indicating that PQ is required for the change but is not the site of the UV inhibition. Carotenoid, lipid and protein content and complement in irradiated and unirradiated chloroplasts and cells were also compared. In no case was any major alteration noted. Measurements were made of the effects of UV irradiation on the variable-yield fluorescence of isolated chloroplasts and whole cells. It was expected that as photosynthetic activity decreased the variable-yield fluorescence would increase until the maximum attainable yield was reached when photosynthetic activity had been totally abolished. Surprisingly, it was found that the variable-yield fluorescence decreased after UV irradiation and, more important, the maximum attainable yield also decreased. This was interpreted as indicating that the fluorescence emitter, the system II trapping center, was destroyed. Considering all of the results discussed above, it seems likely that UV irradiation disrupts a physical entity consisting of the system II trapping center, the initial electron acceptor from system II, and at least one component beyond the site of DCMU inhibition. This interpretation further suggests that system II consists of a physical unit containing several components of the electron transport chain. Close

• 28759. [Article] Spatio-Temporal Analysis and Modeling in the Marine Environment : Humpback Whale Genetic Variability and Seabird Distributions in the Northeastern Pacific Ocean

  The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas ...

  Citation × Citation Citation Abstract Copy Title: Spatio-Temporal Analysis and Modeling in the Marine Environment : Humpback Whale Genetic Variability and Seabird Distributions in the Northeastern Pacific Ocean Author: Dick, Dorothy Marie The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas (MPA) to slow the loss of marine biodiversity. One approach to MPA creation advocates targeting marine megafauna (e.g., marine mammals, seabirds, sharks, etc.) and assumes protective measures for megafauna will extend safeguards to areas of ocean productivity and other species dependent on that productivity. The marine spatial planning (MSP) process requires spatially-explicit information resulting in the development of map products used in planning and decision making. The crux of map creation is georeferenced species occurrence data. This three-part study takes a multidisciplinary approach, combining geography, marine conservation, molecular ecology, and spatial ecology to explore species occurrence data and development of novel geoanalytical tools, spatial analyses, and predictive modeling to inform the MSP process and help design more effective MPA networks for North Pacific marine megafauna (humpback whales and seabirds). Chapter 2 includes the development of geneGIS, a customized Arc Marine data model and suite of computational GIS tools to explore, analyze, and visualize spatially-explicit, individual-based records from North Pacific humpback whale photo-identification and genetic data. Unlike most occurrence data, this presence-only dataset is enriched by the addition of genetic information enabling mangers to factor in population structure and genetic diversity, and thus maximize species resilience, when designing MPAs. Chapters 3 and 4 focus on using presence-absence data to develop spatially-explicit ecological models to identify multispecies seabird foraging aggregations (hotspots) and assess how these locations may shift with climate change within the California Current System. Key to both components is an improved understanding of what factors influence the presence of a species and/or its genetic variability to enable present day planning and design of MPA networks to ensure adequate protection will be in place now and as climate change progresses. This information can also be used to inform policy decisions by adapting strategies to reduce non-climate stressors such as fishery pressures and coastal development in areas predicted to be important to marine species in the future. Title: Spatio-Temporal Analysis and Modeling in the Marine Environment : Humpback Whale Genetic Variability and Seabird Distributions in the Northeastern Pacific Ocean Author: Dick, Dorothy Marie The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas (MPA) to slow the loss of marine biodiversity. One approach to MPA creation advocates targeting marine megafauna (e.g., marine mammals, seabirds, sharks, etc.) and assumes protective measures for megafauna will extend safeguards to areas of ocean productivity and other species dependent on that productivity. The marine spatial planning (MSP) process requires spatially-explicit information resulting in the development of map products used in planning and decision making. The crux of map creation is georeferenced species occurrence data. This three-part study takes a multidisciplinary approach, combining geography, marine conservation, molecular ecology, and spatial ecology to explore species occurrence data and development of novel geoanalytical tools, spatial analyses, and predictive modeling to inform the MSP process and help design more effective MPA networks for North Pacific marine megafauna (humpback whales and seabirds). Chapter 2 includes the development of geneGIS, a customized Arc Marine data model and suite of computational GIS tools to explore, analyze, and visualize spatially-explicit, individual-based records from North Pacific humpback whale photo-identification and genetic data. Unlike most occurrence data, this presence-only dataset is enriched by the addition of genetic information enabling mangers to factor in population structure and genetic diversity, and thus maximize species resilience, when designing MPAs. Chapters 3 and 4 focus on using presence-absence data to develop spatially-explicit ecological models to identify multispecies seabird foraging aggregations (hotspots) and assess how these locations may shift with climate change within the California Current System. Key to both components is an improved understanding of what factors influence the presence of a species and/or its genetic variability to enable present day planning and design of MPA networks to ensure adequate protection will be in place now and as climate change progresses. This information can also be used to inform policy decisions by adapting strategies to reduce non-climate stressors such as fishery pressures and coastal development in areas predicted to be important to marine species in the future. Close

• 28760. [Article] Culture and identity expression in interiors : an ethnography of sorority study rooms

  This ethnographic study describes the patterns of decorating in the study rooms of university sorority women. The primary method of data were collection was by means of interviews with sorority members. ...

  Citation × Citation Citation Abstract Copy Title: Culture and identity expression in interiors : an ethnography of sorority study rooms Author: Carter, Bev This ethnographic study describes the patterns of decorating in the study rooms of university sorority women. The primary method of data were collection was by means of interviews with sorority members. Observations and photographs of the study rooms of these members supplemented the interviews and provided validation for categorization purposes. A large body of research exists related to the effects and implications of sorority membership. Because much of this research is quantitative, it does not allow for the descriptive type data collected in the context of the culture which may be utilized in a qualitative study. The purpose of the present study was to document the decorating patterns of the informants and to identify cultural values and expressions of individual identity in the decoration of their living spaces. This study contributes to existing research on college student decorating patterns by relating the items used for decorations to cultural and individual values. In addition, it provides a detailed description of how the space in the study rooms is utilized. The data are also evaluated based on demographic information gathered. The results of this study indicated that the members of Alpha Beta sorority expressed certain cultural values by using similar items to decorate their rooms and by exhibiting common ways of using their living space. One of the values expressed by the members in their decorating was that of comfort, both physical and mental. Comfort was demonstrated in conditions such as the degree of tidiness of the room, the color scheme, the photos on display or the level of self expression available to the individual. Examples of identity expression were also evident in these study rooms. Items indicating personal accomplishments, items from personal collections and objects used for hobbies were found in many rooms. Conclusions drawn from this study were first, that the desire to decorate was nearly universal among the members of Alpha Beta sorority. Second, the desire for self expression seemed to be a significant motivation for decorating, although there was evidence of some peer pressure as well. Third, decorating generally, and decorating using a theme, appeared to be a behavior members embraced more readily over time. Interactions over time allowed for the cultural values related to decorating the study room to be acquired. This process is facilitated by the significance of the social network within the sorority culture. This study contributes to an understanding of how cultural and personal values are expressed in the study rooms of sorority women, and by extension, the values that could be expected in other interior environments. Title: Culture and identity expression in interiors : an ethnography of sorority study rooms Author: Carter, Bev This ethnographic study describes the patterns of decorating in the study rooms of university sorority women. The primary method of data were collection was by means of interviews with sorority members. Observations and photographs of the study rooms of these members supplemented the interviews and provided validation for categorization purposes. A large body of research exists related to the effects and implications of sorority membership. Because much of this research is quantitative, it does not allow for the descriptive type data collected in the context of the culture which may be utilized in a qualitative study. The purpose of the present study was to document the decorating patterns of the informants and to identify cultural values and expressions of individual identity in the decoration of their living spaces. This study contributes to existing research on college student decorating patterns by relating the items used for decorations to cultural and individual values. In addition, it provides a detailed description of how the space in the study rooms is utilized. The data are also evaluated based on demographic information gathered. The results of this study indicated that the members of Alpha Beta sorority expressed certain cultural values by using similar items to decorate their rooms and by exhibiting common ways of using their living space. One of the values expressed by the members in their decorating was that of comfort, both physical and mental. Comfort was demonstrated in conditions such as the degree of tidiness of the room, the color scheme, the photos on display or the level of self expression available to the individual. Examples of identity expression were also evident in these study rooms. Items indicating personal accomplishments, items from personal collections and objects used for hobbies were found in many rooms. Conclusions drawn from this study were first, that the desire to decorate was nearly universal among the members of Alpha Beta sorority. Second, the desire for self expression seemed to be a significant motivation for decorating, although there was evidence of some peer pressure as well. Third, decorating generally, and decorating using a theme, appeared to be a behavior members embraced more readily over time. Interactions over time allowed for the cultural values related to decorating the study room to be acquired. This process is facilitated by the significance of the social network within the sorority culture. This study contributes to an understanding of how cultural and personal values are expressed in the study rooms of sorority women, and by extension, the values that could be expected in other interior environments. Close