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• 1. [Article] Twentieth-Century Trends in Runoff, Evapotranspiration, and Soil Moisture in the Western United States

  A physically based hydrology model is used to produce time series for the period 1916–2003 of evapotranspiration (ET), runoff, and soil moisture (SM) over the western United States from which long-term ...

  Citation × Citation Citation Abstract Copy Title: Twentieth-Century Trends in Runoff, Evapotranspiration, and Soil Moisture in the Western United States Author: Clark, Martyn P., Lettenmaier, Dennis P., Mote, Philip W., Hamlet, Alan F. A physically based hydrology model is used to produce time series for the period 1916–2003 of evapotranspiration (ET), runoff, and soil moisture (SM) over the western United States from which long-term trends are evaluated. The results show that trends in ET in spring and summer are determined primarily by trends in precipitation and snowmelt that determine water availability. From April to June, ET trends are mostly positive due primarily to earlier snowmelt and earlier emergence of snow-free ground, and secondarily to increasing trends in spring precipitation. From July to September trends in ET are more strongly influenced by precipitation trends, with the exception of areas (most notably California) that receive little summer precipitation and have experienced large changes in snowmelt timing. Trends in the seasonal timing of ET are modest, but during the period 1947–2003 when temperature trends are large, they reflect a shift of ET from midsummer to early summer and late spring. As in other studies, it is found that runoff is occurring earlier in spring, a trend that is related primarily to increasing temperature, and is most apparent during 1947–2003. Trends in the annual runoff ratio, a variable critical to western water management, are determined primarily by trends in cool season precipitation, rather than changes in the timing of runoff or ET. It was found that the signature of temperature-related trends in runoff and SM is strongly keyed to mean midwinter [December–February (DJF)] temperatures. Areas with warmer winter temperatures show increasing trends in the runoff fraction as early as February, and colder areas as late as June. Trends toward earlier spring SM recharge are apparent and increasing trends in SM on 1 April are evident over much of the region. The 1 July SM trends are less affected by snowmelt changes and are controlled more by precipitation trends. Title: Twentieth-Century Trends in Runoff, Evapotranspiration, and Soil Moisture in the Western United States Author: Clark, Martyn P., Lettenmaier, Dennis P., Mote, Philip W., Hamlet, Alan F. A physically based hydrology model is used to produce time series for the period 1916–2003 of evapotranspiration (ET), runoff, and soil moisture (SM) over the western United States from which long-term trends are evaluated. The results show that trends in ET in spring and summer are determined primarily by trends in precipitation and snowmelt that determine water availability. From April to June, ET trends are mostly positive due primarily to earlier snowmelt and earlier emergence of snow-free ground, and secondarily to increasing trends in spring precipitation. From July to September trends in ET are more strongly influenced by precipitation trends, with the exception of areas (most notably California) that receive little summer precipitation and have experienced large changes in snowmelt timing. Trends in the seasonal timing of ET are modest, but during the period 1947–2003 when temperature trends are large, they reflect a shift of ET from midsummer to early summer and late spring. As in other studies, it is found that runoff is occurring earlier in spring, a trend that is related primarily to increasing temperature, and is most apparent during 1947–2003. Trends in the annual runoff ratio, a variable critical to western water management, are determined primarily by trends in cool season precipitation, rather than changes in the timing of runoff or ET. It was found that the signature of temperature-related trends in runoff and SM is strongly keyed to mean midwinter [December–February (DJF)] temperatures. Areas with warmer winter temperatures show increasing trends in the runoff fraction as early as February, and colder areas as late as June. Trends toward earlier spring SM recharge are apparent and increasing trends in SM on 1 April are evident over much of the region. The 1 July SM trends are less affected by snowmelt changes and are controlled more by precipitation trends. Close

• 2. [Article] Teachers' beliefs and willingness to be involved with certain aspects of Oregon home economics education curriculum

  The purpose of this study was designed to answer 1. What are the beliefs and attitudes that Oregon home economics teachers hold about various new trends? 2. Are Oregon home economics teachers willing to ...

  Citation × Citation Citation Abstract Copy Title: Teachers' beliefs and willingness to be involved with certain aspects of Oregon home economics education curriculum Author: Alexander, Capi Forsgren The purpose of this study was designed to answer 1. What are the beliefs and attitudes that Oregon home economics teachers hold about various new trends? 2. Are Oregon home economics teachers willing to support the various new trends? 3. Are Oregon home economics teachers willing to further prepare themselves to work with the trends? 4. Are Oregon home economics teachers willing to accept teaching responsibilities for the trends? 5. Are Oregon home economics teachers willing to assume leadership responsibilities for the trends? The six trends included in the study were related to programs for 1. The handicapped 2. The socio-economically disadvantaged 3. Occupational education 4. Coeducational classes 5. Specialized semester courses 6. Family life courses A questionnaire was constructed, validated, and sent to 394 home economics teachers in the State of Oregon to gain answers to the five questions as they related to the six trends. Of the questionnaires mailed out, 241 were returned and 160 (41 percent) were usable. Nearly one half of the respondents were 40 years of age or older. Approximately two thirds were married. Nearly 70 percent received their bachelor's degrees since 1940. Fewer than 15 percent of the respondents had master's degrees and over 80 percent of these were received since 1960. About one half of the teachers had taken from 1-42 quarter hours beyond their last degree. At least one half of the respondents had had six or fewer years teaching experience and some experience in teaching other subject matter areas. Most (two thirds) taught in senior high schools where enrollments of more than one half of the schools were less than 1,000. Nearly one half of the respondents did not indicate that boys were a part of their program. Analysis of data showed that the respondents held quite positive beliefs concerning each of the six trends. For every trend, except programs for the handicapped, at least 70 percent felt that the home economics education programs were very important or moderately important. Fewer than five percent had negative feelings about any of the trends excepting programs for the handicapped and occupational education where 30 percent and 12 percent of the replies were negative and most often showed the feeling that respondents felt other groups were better qualified. The respondents showed a general willingness to support the trends with at least three fourths giving positive replies for every trend except programs for the handicapped and coeducational classes. The majority of the positive responses showed that the respondents were most interested in indirect types of support rather than active support. Negative replies most often showed that respondents believed other programs were more important, that they did not have time to support the trend, or that there was no need for the program in their community. Over one half of the respondents were willing to further prepare themselves for involvement in the six trends and were most interested in family life courses, occupational education and programs for the socio-economically disadvantaged. Special workshops was most often indicated as the preferred method of preparation. Negative replies showed that respondents were more interested in other areas or were already prepared. At least 80 percent of the respondents were willing to assume teaching responsibilities for every trend except occupational education and programs for the handicapped. Respondents often said they would teach in these trends only if they were given special preparation or if they were given time to prepare. Replies in the negative category most often indicated that the respondents were already involved or were more interested in other areas. Although nearly 70 percent of the respondents would assume leadership roles for family life, specialized semester, and coeducational classes, fewer than one half would take on this responsibility for occupational education and programs for the socio- economically disadvantaged and fewer than one fourth would lead programs for the handicapped. Respondents who replied negatively felt that they did not have the background or did not have the time or interest. The following conclusions were reached. 1. The majority of the respondents held favorable attitudes about the six trends. 2. Programs for the handicapped, the socio- economically disadvantaged, and occupational education followed similar patterns of acceptance and of respondents' willingness to be involved, while coeducational classes, specialized semester courses, family life courses were more accepted than the first three trends. Title: Teachers' beliefs and willingness to be involved with certain aspects of Oregon home economics education curriculum Author: Alexander, Capi Forsgren The purpose of this study was designed to answer 1. What are the beliefs and attitudes that Oregon home economics teachers hold about various new trends? 2. Are Oregon home economics teachers willing to support the various new trends? 3. Are Oregon home economics teachers willing to further prepare themselves to work with the trends? 4. Are Oregon home economics teachers willing to accept teaching responsibilities for the trends? 5. Are Oregon home economics teachers willing to assume leadership responsibilities for the trends? The six trends included in the study were related to programs for 1. The handicapped 2. The socio-economically disadvantaged 3. Occupational education 4. Coeducational classes 5. Specialized semester courses 6. Family life courses A questionnaire was constructed, validated, and sent to 394 home economics teachers in the State of Oregon to gain answers to the five questions as they related to the six trends. Of the questionnaires mailed out, 241 were returned and 160 (41 percent) were usable. Nearly one half of the respondents were 40 years of age or older. Approximately two thirds were married. Nearly 70 percent received their bachelor's degrees since 1940. Fewer than 15 percent of the respondents had master's degrees and over 80 percent of these were received since 1960. About one half of the teachers had taken from 1-42 quarter hours beyond their last degree. At least one half of the respondents had had six or fewer years teaching experience and some experience in teaching other subject matter areas. Most (two thirds) taught in senior high schools where enrollments of more than one half of the schools were less than 1,000. Nearly one half of the respondents did not indicate that boys were a part of their program. Analysis of data showed that the respondents held quite positive beliefs concerning each of the six trends. For every trend, except programs for the handicapped, at least 70 percent felt that the home economics education programs were very important or moderately important. Fewer than five percent had negative feelings about any of the trends excepting programs for the handicapped and occupational education where 30 percent and 12 percent of the replies were negative and most often showed the feeling that respondents felt other groups were better qualified. The respondents showed a general willingness to support the trends with at least three fourths giving positive replies for every trend except programs for the handicapped and coeducational classes. The majority of the positive responses showed that the respondents were most interested in indirect types of support rather than active support. Negative replies most often showed that respondents believed other programs were more important, that they did not have time to support the trend, or that there was no need for the program in their community. Over one half of the respondents were willing to further prepare themselves for involvement in the six trends and were most interested in family life courses, occupational education and programs for the socio-economically disadvantaged. Special workshops was most often indicated as the preferred method of preparation. Negative replies showed that respondents were more interested in other areas or were already prepared. At least 80 percent of the respondents were willing to assume teaching responsibilities for every trend except occupational education and programs for the handicapped. Respondents often said they would teach in these trends only if they were given special preparation or if they were given time to prepare. Replies in the negative category most often indicated that the respondents were already involved or were more interested in other areas. Although nearly 70 percent of the respondents would assume leadership roles for family life, specialized semester, and coeducational classes, fewer than one half would take on this responsibility for occupational education and programs for the socio- economically disadvantaged and fewer than one fourth would lead programs for the handicapped. Respondents who replied negatively felt that they did not have the background or did not have the time or interest. The following conclusions were reached. 1. The majority of the respondents held favorable attitudes about the six trends. 2. Programs for the handicapped, the socio- economically disadvantaged, and occupational education followed similar patterns of acceptance and of respondents' willingness to be involved, while coeducational classes, specialized semester courses, family life courses were more accepted than the first three trends. Close

• 3. [Article] An identification of and a comparison between trends in clothing and textiles in a selected group of colleges and universities

  The purpose of this study was to identify the most recent trends in Clothing and Textiles, to find whether any relationship existed between them, and whether there was difference of emphasis between large ...

  Citation × Citation Citation Abstract Copy Title: An identification of and a comparison between trends in clothing and textiles in a selected group of colleges and universities Author: Jacobsz, Maretha Stephanie The purpose of this study was to identify the most recent trends in Clothing and Textiles, to find whether any relationship existed between them, and whether there was difference of emphasis between large and small schools. The information about existing trends in Clothing and Textiles was collected from literature published in Clothing and Textiles Teachers Conference Reports and in Home Economics journals In addition, twenty catalogs from schools offering majors in Clothing and Textiles were analyzed for course content and educational objectives. The schools were divided in large and small categories according to the number of students enrolled as majors in Home Economics. From the literature it was concluded that the following four pairs of opposing trends existed: development of creative abilities, the development of skills; breadth in subject matter, depth in subject matter; family centeredness, subject matter orientation; general education, and professional education. A questionnaire was devised which tested the opposing trends in the four areas of Clothing and Textiles (clothing construction, clothing selection, textiles, and consumer economics). The face-validity was checked by nine faculty members experienced in the area of Clothing and Textiles, and rechecked by three Home Economics department heads and one textiles advisor, before it was finally sent out. The questions in the first part were indirect forced-choice type and referred only to the beginning courses. In Part II, the eight trends were independently listed and each department head was asked to rate her department as to the amount of emphasis given on the issues. The questionnaires were sent to 112 colleges and universities in the United States which offered Clothing and Textiles as a major in their Home Economics program. The chairmen of the departments were asked to participate and to return the completed questionnaires, of which 54 percent were returned, The returned questionnaires were statistically analyzed in the following way: means were determined for the trends for the indirect questions in Part I and for the ranking of trends in Part II in order to determine whether the trends existed and which were considered most important; Pearson r correlations were used to find the relationships between any of the trends in Part I, in Part II, and between Part I and Part II; t-test of mean differences between large and small schools were computed for each trend to find whether the difference was significant; and an analysis of variance was performed to find the significance of variance within the four areas of Clothing and Textiles in each of the trends. Data collected revealed that the mean scores of trends differed and that breadth in subject matter scored highest in both parts of the device. Significant correlations existed between all trends in the indirect questions, and between a few trends in the direct rating scale. The relations of creativity in the latter with breadth, depth, family centeredness and subject matter were the most significant. Correlations existed between some of the trends in both parts of the questionnaire, namely: breadth, family centeredness, between general and family centeredness, and between professional and depth. The opposing trends were in the negative direction. The significant relations of all trends in the beginning courses might be due to the tendency to teach the mastery of skills, breadth in subject matter with subject matter emphasis in the professional curricula. There were no significant differences in the mean scores between large and small schools but significant F ratios were found within the four areas of Clothing and Textiles for each pair of variables for the small schools and between one pair of variables for the large schools. An analysis of the course offerings, course content, and educational objectives were made from the catalog material. This revealed differences between small and large schools in general requirements for graduation and course offerings in Clothing and Textiles. Based on this information it was concluded that the small schools were more concerned with individual development of the students through a wide variety of general education courses, while the larger schools offered more courses within Clothing and Textiles and were more concerned with preparation for a professional career. Title: An identification of and a comparison between trends in clothing and textiles in a selected group of colleges and universities Author: Jacobsz, Maretha Stephanie The purpose of this study was to identify the most recent trends in Clothing and Textiles, to find whether any relationship existed between them, and whether there was difference of emphasis between large and small schools. The information about existing trends in Clothing and Textiles was collected from literature published in Clothing and Textiles Teachers Conference Reports and in Home Economics journals In addition, twenty catalogs from schools offering majors in Clothing and Textiles were analyzed for course content and educational objectives. The schools were divided in large and small categories according to the number of students enrolled as majors in Home Economics. From the literature it was concluded that the following four pairs of opposing trends existed: development of creative abilities, the development of skills; breadth in subject matter, depth in subject matter; family centeredness, subject matter orientation; general education, and professional education. A questionnaire was devised which tested the opposing trends in the four areas of Clothing and Textiles (clothing construction, clothing selection, textiles, and consumer economics). The face-validity was checked by nine faculty members experienced in the area of Clothing and Textiles, and rechecked by three Home Economics department heads and one textiles advisor, before it was finally sent out. The questions in the first part were indirect forced-choice type and referred only to the beginning courses. In Part II, the eight trends were independently listed and each department head was asked to rate her department as to the amount of emphasis given on the issues. The questionnaires were sent to 112 colleges and universities in the United States which offered Clothing and Textiles as a major in their Home Economics program. The chairmen of the departments were asked to participate and to return the completed questionnaires, of which 54 percent were returned, The returned questionnaires were statistically analyzed in the following way: means were determined for the trends for the indirect questions in Part I and for the ranking of trends in Part II in order to determine whether the trends existed and which were considered most important; Pearson r correlations were used to find the relationships between any of the trends in Part I, in Part II, and between Part I and Part II; t-test of mean differences between large and small schools were computed for each trend to find whether the difference was significant; and an analysis of variance was performed to find the significance of variance within the four areas of Clothing and Textiles in each of the trends. Data collected revealed that the mean scores of trends differed and that breadth in subject matter scored highest in both parts of the device. Significant correlations existed between all trends in the indirect questions, and between a few trends in the direct rating scale. The relations of creativity in the latter with breadth, depth, family centeredness and subject matter were the most significant. Correlations existed between some of the trends in both parts of the questionnaire, namely: breadth, family centeredness, between general and family centeredness, and between professional and depth. The opposing trends were in the negative direction. The significant relations of all trends in the beginning courses might be due to the tendency to teach the mastery of skills, breadth in subject matter with subject matter emphasis in the professional curricula. There were no significant differences in the mean scores between large and small schools but significant F ratios were found within the four areas of Clothing and Textiles for each pair of variables for the small schools and between one pair of variables for the large schools. An analysis of the course offerings, course content, and educational objectives were made from the catalog material. This revealed differences between small and large schools in general requirements for graduation and course offerings in Clothing and Textiles. Based on this information it was concluded that the small schools were more concerned with individual development of the students through a wide variety of general education courses, while the larger schools offered more courses within Clothing and Textiles and were more concerned with preparation for a professional career. Close

• 4. [Article] Height-related trends in structure and function of Douglas-fir foliage

  This dissertation investigated the impacts of tree height upon a range of physiological and structural characteristics of Douglas-fir foliage; relationships between structural and functional trends with ...

  Citation × Citation Citation Abstract Copy Title: Height-related trends in structure and function of Douglas-fir foliage Author: Woodruff, David R. This dissertation investigated the impacts of tree height upon a range of physiological and structural characteristics of Douglas-fir foliage; relationships between structural and functional trends with height; and compensatory mechanisms that mitigate height-related growth constraints. Height-related trends in foliar physiological and anatomical characteristics were examined both within trees as well as between trees of different heights. Emphasis was placed on discovering the mechanistic nature of the observed growth constraints and adaptive strategies. This research was conducted in the interest of enhancing our knowledge of the causes of age- and size-related decline in forest productivity. The research conducted for this dissertation explored several previously uninvestigated mechanisms for size-related reductions in forest productivity that are associated with tree foliar structure and function. Height-related trends in foliar turgor associated with the gravitational hydrostatic pressure gradient were identified as well as subsequent impacts on leaf and shoot morphology. Osmotic potential declined with height providing evidence of osmotic adjustment to offset the height-related decline in leaf turgor. This osmotic adjustment occurred only seasonally, and not during the spring when turgor maintenance is most important for leaf expansion. Gradients in leaf turgor were reflected in height-related trends in leaf and shoot morphology. Previous work has documented height-related trends in foliar morphological characteristics and earlier studies have examined osmotic adjustment as an adaptation to drought and salinity stress. Height-related trends in foliar morphological characteristics have typically been attributed to light gradients along vertical profiles. The work in this dissertation is the first to evaluate the effects of the gravitational component of water potential on the osmotic, morphological and growth characteristics of foliage along a height gradient in tall trees. Trends in leaf hydraulic efficiency and safety along a height gradient were examined, and correlations between changes in leaf hydraulic conductance (Kleaf) and changes in stomatal conductance (gs) were identified that provided evidence of a control mechanism for gs. A consistent relationship was discovered between changes in Kleaf and gs providing evidence that leaf tracheid embolism is associated with stomatal closure during periods of declining water availability. Hydraulic vulnerability curves of foliage collected at different heights indicated that increased height is correlated with reduced hydraulic efficiency and increased hydraulic safety. These opposing trends suggest the existence of a compensatory mechanism in foliage that functions to reduce hydraulic vulnerability at the expense of transport capacity. The research in this dissertation is the first to examine the dynamic relationships between leaf hydraulics and stomatal behavior in temperate conifers, and the first to examine how these characteristics are affected by tree height. Height-related trends in leaf xylem anatomical characteristics were examined and strong correlations were identified between these anatomical characteristics and the patterns of leaf hydraulic efficiency and safety that were observed in previous work for this dissertation. Theoretical estimates of leaf hydraulic efficiency (Kleaf-theoretical) based upon the Hagen-Pouseille equation and measured leaf tracheid anatomical characteristics were strongly correlated with laboratory measurements of Kleaf, providing further evidence of a causal relationship between height-related trends in both leaf tracheid anatomical properties and leaf hydraulic function. Earlier studies have documented connections between leaf anatomical characteristics and leaf physiological characteristics such as correlations between leaf architecture and gas exchange and leaf architecture and transport efficiency. The research in this dissertation however, is the first to examine the impact of tree height on leaf anatomical characteristics and associated shoot physiological properties. Trends in gas-exchange along a height gradient were identified, independent of the immediate effects of path length and gravitational resistance. Photosynthesis under ambient [CO2] declined with height in a manner that was consistent with height-related trends in mesophyll anatomy and independent of leaf nitrogen content. Analyses of mesophyll resistance from assimilation versus internal CO2 concentration (A-Ci) curves indicated that height-related trends in mesophyll resistance were correlated with trends in both photosynthesis and mesophyll anatomy along a height gradient. Analyses of integrated and instantaneous water use efficiency indicated that height-related trends in integrated water use efficiency are attributable to the effects of path length and gravity on stomatal behavior as opposed to a height-related trend in intrinsic foliar properties. The research in this dissertation is the first to isolate the influence of height-related trends in foliar structure on different gas exchange properties such as assimilation and mesophyll conductance, independent of the direct effects of vertical gradients in xylem tension on stomatal and photosynthetic physiology. Title: Height-related trends in structure and function of Douglas-fir foliage Author: Woodruff, David R. This dissertation investigated the impacts of tree height upon a range of physiological and structural characteristics of Douglas-fir foliage; relationships between structural and functional trends with height; and compensatory mechanisms that mitigate height-related growth constraints. Height-related trends in foliar physiological and anatomical characteristics were examined both within trees as well as between trees of different heights. Emphasis was placed on discovering the mechanistic nature of the observed growth constraints and adaptive strategies. This research was conducted in the interest of enhancing our knowledge of the causes of age- and size-related decline in forest productivity. The research conducted for this dissertation explored several previously uninvestigated mechanisms for size-related reductions in forest productivity that are associated with tree foliar structure and function. Height-related trends in foliar turgor associated with the gravitational hydrostatic pressure gradient were identified as well as subsequent impacts on leaf and shoot morphology. Osmotic potential declined with height providing evidence of osmotic adjustment to offset the height-related decline in leaf turgor. This osmotic adjustment occurred only seasonally, and not during the spring when turgor maintenance is most important for leaf expansion. Gradients in leaf turgor were reflected in height-related trends in leaf and shoot morphology. Previous work has documented height-related trends in foliar morphological characteristics and earlier studies have examined osmotic adjustment as an adaptation to drought and salinity stress. Height-related trends in foliar morphological characteristics have typically been attributed to light gradients along vertical profiles. The work in this dissertation is the first to evaluate the effects of the gravitational component of water potential on the osmotic, morphological and growth characteristics of foliage along a height gradient in tall trees. Trends in leaf hydraulic efficiency and safety along a height gradient were examined, and correlations between changes in leaf hydraulic conductance (Kleaf) and changes in stomatal conductance (gs) were identified that provided evidence of a control mechanism for gs. A consistent relationship was discovered between changes in Kleaf and gs providing evidence that leaf tracheid embolism is associated with stomatal closure during periods of declining water availability. Hydraulic vulnerability curves of foliage collected at different heights indicated that increased height is correlated with reduced hydraulic efficiency and increased hydraulic safety. These opposing trends suggest the existence of a compensatory mechanism in foliage that functions to reduce hydraulic vulnerability at the expense of transport capacity. The research in this dissertation is the first to examine the dynamic relationships between leaf hydraulics and stomatal behavior in temperate conifers, and the first to examine how these characteristics are affected by tree height. Height-related trends in leaf xylem anatomical characteristics were examined and strong correlations were identified between these anatomical characteristics and the patterns of leaf hydraulic efficiency and safety that were observed in previous work for this dissertation. Theoretical estimates of leaf hydraulic efficiency (Kleaf-theoretical) based upon the Hagen-Pouseille equation and measured leaf tracheid anatomical characteristics were strongly correlated with laboratory measurements of Kleaf, providing further evidence of a causal relationship between height-related trends in both leaf tracheid anatomical properties and leaf hydraulic function. Earlier studies have documented connections between leaf anatomical characteristics and leaf physiological characteristics such as correlations between leaf architecture and gas exchange and leaf architecture and transport efficiency. The research in this dissertation however, is the first to examine the impact of tree height on leaf anatomical characteristics and associated shoot physiological properties. Trends in gas-exchange along a height gradient were identified, independent of the immediate effects of path length and gravitational resistance. Photosynthesis under ambient [CO2] declined with height in a manner that was consistent with height-related trends in mesophyll anatomy and independent of leaf nitrogen content. Analyses of mesophyll resistance from assimilation versus internal CO2 concentration (A-Ci) curves indicated that height-related trends in mesophyll resistance were correlated with trends in both photosynthesis and mesophyll anatomy along a height gradient. Analyses of integrated and instantaneous water use efficiency indicated that height-related trends in integrated water use efficiency are attributable to the effects of path length and gravity on stomatal behavior as opposed to a height-related trend in intrinsic foliar properties. The research in this dissertation is the first to isolate the influence of height-related trends in foliar structure on different gas exchange properties such as assimilation and mesophyll conductance, independent of the direct effects of vertical gradients in xylem tension on stomatal and photosynthetic physiology. Close

• 5. [Article] Climate-Driven Variability and Trends in Mountain Snowpack in Western North America

  Records of 1 April snow water equivalent (SWE) are examined here using multiple linear regression against reference time series of temperature and precipitation. This method permits 1) an examination of ...

  Citation × Citation Citation Abstract Copy Title: Climate-Driven Variability and Trends in Mountain Snowpack in Western North America Author: Mote, Philip W. Records of 1 April snow water equivalent (SWE) are examined here using multiple linear regression against reference time series of temperature and precipitation. This method permits 1) an examination of the separate roles of temperature and precipitation in determining the trends in SWE; 2) an estimation of the sensitivity of SWE to warming trends, and its distribution across western North America and as a function of elevation; and 3) inferences about responses of SWE to future warming. These results emphasize the sensitivity to warming of the mountains of northern California and the Cascades of Oregon and Washington. In addition, the contribution of modes of Pacific climate variability is examined and found to be responsible for about 10%–60% of the trends in SWE, depending on the period of record and climate index. Title: Climate-Driven Variability and Trends in Mountain Snowpack in Western North America Author: Mote, Philip W. Records of 1 April snow water equivalent (SWE) are examined here using multiple linear regression against reference time series of temperature and precipitation. This method permits 1) an examination of the separate roles of temperature and precipitation in determining the trends in SWE; 2) an estimation of the sensitivity of SWE to warming trends, and its distribution across western North America and as a function of elevation; and 3) inferences about responses of SWE to future warming. These results emphasize the sensitivity to warming of the mountains of northern California and the Cascades of Oregon and Washington. In addition, the contribution of modes of Pacific climate variability is examined and found to be responsible for about 10%–60% of the trends in SWE, depending on the period of record and climate index. Close

• 6. [Article] Retail Seafood: A New Paradigm

  The presenter discusses supply trends, consumer trends, retail trends and new product opportunities.

  Citation × Citation Citation Abstract Copy Title: Retail Seafood: A New Paradigm Author: Johnson, Howard M. Year: 2001 The presenter discusses supply trends, consumer trends, retail trends and new product opportunities. Title: Retail Seafood: A New Paradigm Author: Johnson, Howard M. Year: 2001 The presenter discusses supply trends, consumer trends, retail trends and new product opportunities. Close

• 7. [Article] Long-Term Sea Surface Temperature Variability along the U.S. East Coast

  Sea surface temperature variations along the entire U.S. East Coast from 1875 to 2007 are characterized using a collection of historical observations from lighthouses and lightships combined with recent ...

  Citation × Citation Citation Abstract Copy Title: Long-Term Sea Surface Temperature Variability along the U.S. East Coast Author: Shearman, R. Kipp, Lentz, Steven J. Sea surface temperature variations along the entire U.S. East Coast from 1875 to 2007 are characterized using a collection of historical observations from lighthouses and lightships combined with recent buoy and shore-based measurements. Long-term coastal temperature trends are warming in the Gulf of Maine [1.0° ± 0.3°C (100 yr)⁻¹] and Middle Atlantic Bight [0.7° ± 0.3°C (100 yr)⁻¹], whereas trends are weakly cooling or not significant in the South Atlantic Bight [−0.1° ± 0.3°C (100 yr)⁻¹] and off Florida [−0.3° ± 0.2°C (100 yr)⁻¹]. Over the last century, temperatures along the northeastern U.S. coast have warmed at a rate 1.8–2.5 times the regional atmospheric temperature trend but are comparable to warming rates for the Arctic and Labrador, the source of coastal ocean waters north of Cape Hatteras (36°N). South of Cape Hatteras, coastal ocean temperature trends match the regional atmospheric temperature trend. The observations and a simple model show that along-shelf transport, associated with the mean coastal current system running from Labrador to Cape Hatteras, is the mechanism controlling long-term temperature changes for this region and not the local air–sea exchange of heat. Title: Long-Term Sea Surface Temperature Variability along the U.S. East Coast Author: Shearman, R. Kipp, Lentz, Steven J. Sea surface temperature variations along the entire U.S. East Coast from 1875 to 2007 are characterized using a collection of historical observations from lighthouses and lightships combined with recent buoy and shore-based measurements. Long-term coastal temperature trends are warming in the Gulf of Maine [1.0° ± 0.3°C (100 yr)⁻¹] and Middle Atlantic Bight [0.7° ± 0.3°C (100 yr)⁻¹], whereas trends are weakly cooling or not significant in the South Atlantic Bight [−0.1° ± 0.3°C (100 yr)⁻¹] and off Florida [−0.3° ± 0.2°C (100 yr)⁻¹]. Over the last century, temperatures along the northeastern U.S. coast have warmed at a rate 1.8–2.5 times the regional atmospheric temperature trend but are comparable to warming rates for the Arctic and Labrador, the source of coastal ocean waters north of Cape Hatteras (36°N). South of Cape Hatteras, coastal ocean temperature trends match the regional atmospheric temperature trend. The observations and a simple model show that along-shelf transport, associated with the mean coastal current system running from Labrador to Cape Hatteras, is the mechanism controlling long-term temperature changes for this region and not the local air–sea exchange of heat. Close

• 8. [Article] Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes

  Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that ...

  Citation × Citation Citation Abstract Copy Title: Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes Author: Frey, Sarah Jean Kiuama Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that models of both distribution dynamics and population trends accurately reflect reality. However, identification of the appropriate temporal and spatial scales of animal response, and then obtaining data at these scales present two major challenges to developing predictive models. In heterogeneous forested mountain landscapes I examined: A) the relative drivers of climatic variability at fine spatial scales under the forest canopy ('microclimate'), B) the influence of microclimate on local-scale occupancy dynamics of bird communities, and C) the effects of spatial scale and imperfect bird detection on long-term avian population trends. Climate change has been predicted to cause widespread biodiversity declines. However, the capacity of climate envelope models for predicting the future of biodiversity has been questioned due to the mismatch between the scale of available data (i.e., global climate models) and the scales at which organisms experience their environment. Local-scale variation in microclimate is hypothesized to provide potential ‘microrefugia’ for biodiversity, but the relative role of elevation, microtopography, and vegetation structure in driving microclimate is not well known. If the microrefugia hypothesis is true, I expected to see areas on the landscape that remained relatively cooler (i.e., buffered sites). To test this, I collected temperature data at 183 sites across elevation and forest structure gradients in complex terrain of the H. J. Andrews Experimental Forest in the Cascade Mountains of Oregon, USA (Chapter 2). I used boosted regression trees, a novel machine learning approach, to determine the relative influence of vegetation structure, microtopography, and elevation as drivers of microclimate and mapped fine-scale distributions of temperature across the landscape. Models performed extremely well on independent data - cross-validation correlations between testing and training data were 0.69 - 0.98 for ten selected climate variables. Elevation was the dominant driver in fine-scale microclimate patterns, although vegetation and microtopography also showed substantial relative influences. For instance, during the spring-summer transition, maximum monthly temperatures observed in old-growth sites were 2.6°C (95% CI: 1.8 - 3.3°C) cooler than plantation sites and minimum temperatures during winter months were 0.6°C (95% CI: 0.4 - 0.8°C) warmer. This suggests that older forest stands mediate changes in temperature by buffering against warming during summer months and moderating cold temperatures during the winter. Climate is generally considered most influential on species distributions at large spatial scales; however much microclimate variability exists within regional patterns. I tested whether this high degree of microclimate variability has relevance for predicting species distributions and occupancy dynamics of the Andrews Forest bird community. I collected bird occurrence data in 2012 and 2013 at all 183 sites with fine-scale temperature measurements. I used dynamic occupancy models to test the effects of temperature on occupancy and apparent within-season bird movement while statistically accounting for vegetation effects and imperfect bird detection (Chapter 3). Most species (87%) exhibited within-season shifts in response to local-scale temperature metrics. Effects of temperature on within-season occupancy dynamics were as large or larger (1 to 1.7 times) than vegetation. However, individual species were almost as likely to shift toward warmer sites as toward cooler sites, suggesting that microclimate preferences are species-specific. My results emphasize that high-resolution temperature data provide valuable insight into avian distribution dynamics in montane forest environments and that microclimate is an important variable in breeding season habitat selection by forest birds. I hypothesize that microclimate-associated distribution shifts may reflect species' potential for behavioral buffering from climate change in complex terrain. Factors influencing population trends often differ depending on the spatial scale under consideration. Further, accurate estimation of trends requires accounting for biases caused by imperfect detection. To test the degree to which population trends are consistent across scales, I estimated landscape-scale bird population trends from 1999-2012 for 38 species at the Hubbard Brook Experimental Forest (HBEF) in the White Mountains of New Hampshire, USA and compared them to regional and local trends (Chapter 4). I used a new method - open-population binomial mixture models - to test the hypothesis that imperfect detection in bird sampling has the potential to bias trend estimates. I also tested for generalities in species responses by predicting population trends as a function of life history and ecological traits. Landscape-scale trends were correlated with regional and local trends, but generally these correlations were weak (r = 0.12 - 0.4). Further, more species were declining at the regional scale compared to within the relatively undisturbed HBEF. Life history and ecological traits did not explain any of the variability in the HBEF trends. However, at the regional scale, species that occurred at higher elevations were more likely to be declining and species associated with older forests have increased. I hypothesize that these differences could be attributed to both elevated rates of land-use change in the broader region and the fact that the structure of regional data did not permit modeling of imperfect detection. Indeed, accounting for imperfect detection resulted in more accurate population trend estimates at the landscape scale; without accounting for detection we would have both missed trends and falsely identified trends where none existed. These results highlight two important cautions for trend analysis: 1) population trends estimated at fine spatial scales may not be extrapolated to broader scales and 2) accurate trends require accounting for imperfect detection. Title: Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes Author: Frey, Sarah Jean Kiuama Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that models of both distribution dynamics and population trends accurately reflect reality. However, identification of the appropriate temporal and spatial scales of animal response, and then obtaining data at these scales present two major challenges to developing predictive models. In heterogeneous forested mountain landscapes I examined: A) the relative drivers of climatic variability at fine spatial scales under the forest canopy ('microclimate'), B) the influence of microclimate on local-scale occupancy dynamics of bird communities, and C) the effects of spatial scale and imperfect bird detection on long-term avian population trends. Climate change has been predicted to cause widespread biodiversity declines. However, the capacity of climate envelope models for predicting the future of biodiversity has been questioned due to the mismatch between the scale of available data (i.e., global climate models) and the scales at which organisms experience their environment. Local-scale variation in microclimate is hypothesized to provide potential ‘microrefugia’ for biodiversity, but the relative role of elevation, microtopography, and vegetation structure in driving microclimate is not well known. If the microrefugia hypothesis is true, I expected to see areas on the landscape that remained relatively cooler (i.e., buffered sites). To test this, I collected temperature data at 183 sites across elevation and forest structure gradients in complex terrain of the H. J. Andrews Experimental Forest in the Cascade Mountains of Oregon, USA (Chapter 2). I used boosted regression trees, a novel machine learning approach, to determine the relative influence of vegetation structure, microtopography, and elevation as drivers of microclimate and mapped fine-scale distributions of temperature across the landscape. Models performed extremely well on independent data - cross-validation correlations between testing and training data were 0.69 - 0.98 for ten selected climate variables. Elevation was the dominant driver in fine-scale microclimate patterns, although vegetation and microtopography also showed substantial relative influences. For instance, during the spring-summer transition, maximum monthly temperatures observed in old-growth sites were 2.6°C (95% CI: 1.8 - 3.3°C) cooler than plantation sites and minimum temperatures during winter months were 0.6°C (95% CI: 0.4 - 0.8°C) warmer. This suggests that older forest stands mediate changes in temperature by buffering against warming during summer months and moderating cold temperatures during the winter. Climate is generally considered most influential on species distributions at large spatial scales; however much microclimate variability exists within regional patterns. I tested whether this high degree of microclimate variability has relevance for predicting species distributions and occupancy dynamics of the Andrews Forest bird community. I collected bird occurrence data in 2012 and 2013 at all 183 sites with fine-scale temperature measurements. I used dynamic occupancy models to test the effects of temperature on occupancy and apparent within-season bird movement while statistically accounting for vegetation effects and imperfect bird detection (Chapter 3). Most species (87%) exhibited within-season shifts in response to local-scale temperature metrics. Effects of temperature on within-season occupancy dynamics were as large or larger (1 to 1.7 times) than vegetation. However, individual species were almost as likely to shift toward warmer sites as toward cooler sites, suggesting that microclimate preferences are species-specific. My results emphasize that high-resolution temperature data provide valuable insight into avian distribution dynamics in montane forest environments and that microclimate is an important variable in breeding season habitat selection by forest birds. I hypothesize that microclimate-associated distribution shifts may reflect species' potential for behavioral buffering from climate change in complex terrain. Factors influencing population trends often differ depending on the spatial scale under consideration. Further, accurate estimation of trends requires accounting for biases caused by imperfect detection. To test the degree to which population trends are consistent across scales, I estimated landscape-scale bird population trends from 1999-2012 for 38 species at the Hubbard Brook Experimental Forest (HBEF) in the White Mountains of New Hampshire, USA and compared them to regional and local trends (Chapter 4). I used a new method - open-population binomial mixture models - to test the hypothesis that imperfect detection in bird sampling has the potential to bias trend estimates. I also tested for generalities in species responses by predicting population trends as a function of life history and ecological traits. Landscape-scale trends were correlated with regional and local trends, but generally these correlations were weak (r = 0.12 - 0.4). Further, more species were declining at the regional scale compared to within the relatively undisturbed HBEF. Life history and ecological traits did not explain any of the variability in the HBEF trends. However, at the regional scale, species that occurred at higher elevations were more likely to be declining and species associated with older forests have increased. I hypothesize that these differences could be attributed to both elevated rates of land-use change in the broader region and the fact that the structure of regional data did not permit modeling of imperfect detection. Indeed, accounting for imperfect detection resulted in more accurate population trend estimates at the landscape scale; without accounting for detection we would have both missed trends and falsely identified trends where none existed. These results highlight two important cautions for trend analysis: 1) population trends estimated at fine spatial scales may not be extrapolated to broader scales and 2) accurate trends require accounting for imperfect detection. Close

• 9. [Article] The paradox of cooling streams in a warming world:Regional climate trends do not parallel variable local trends in stream temperature in the Pacific continental United States

  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 the American ...

  Citation × Citation Citation Abstract Copy Title: The paradox of cooling streams in a warming world:Regional climate trends do not parallel variable local trends in stream temperature in the Pacific continental United States Author: Haggerty, Roy, Arismendi, Ivan, Hockman-Wert, David, Johnson, Sherri L., Dunham, Jason B. 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 the American Geophysical Union and can be found at: http://www.agu.org/journals/gl/. Title: The paradox of cooling streams in a warming world:Regional climate trends do not parallel variable local trends in stream temperature in the Pacific continental United States Author: Haggerty, Roy, Arismendi, Ivan, Hockman-Wert, David, Johnson, Sherri L., Dunham, Jason B. 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 the American Geophysical Union and can be found at: http://www.agu.org/journals/gl/. Close

• 10. [Article] Changes in the scholastic background and academic ability of summer school students in the Santa Monica, California, junior high schools is from 1956 to 1962

  The purpose of this study was to investigate whether or not change has occurred in the scholastic background and academic ability of students attending the junior high school summer sessions of the Santa ...

  Citation × Citation Citation Abstract Copy Title: Changes in the scholastic background and academic ability of summer school students in the Santa Monica, California, junior high schools is from 1956 to 1962 Author: Verge, Arthur Charles The purpose of this study was to investigate whether or not change has occurred in the scholastic background and academic ability of students attending the junior high school summer sessions of the Santa Monica Unified School District, California, between the years 1956 and 1962. Applying a Fisher and Yates Table of Randomized Numbers to the total summer school population in each of the years between and including 1956 and 1962, a random selection of 250 students from each year was made. The 1750 students' I.Q. scores, their Iowa Percentile scores, and their Grade Point Averages in the basic yearly subject grades comprised the three variables upon which the statistical analysis was based. Preliminary computations revealed that the means of the three variables generally (15 times out of 18) increased over those of the previous year during 1956 through 1962, and the standard deviation of the various distributions generally remained similar. To determine whether there was a significant linear trend during the years under study and, if so, whether any deviations from that trend were significant, a test of linear regression was applied to the following null hypotheses: scores. (1) There is no linear trend exhibited by the mean I.Q. (2) The relationship of the mean I.Q. scores is not nonlinear. (3) There is no linear trend exhibited by the mean of the Iowa Percentile scores. (4) The relationship of the mean Iowa Percentile scores is not nonlinear. (5) There is no linear trend exhibited by the mean G.P.A. (6) The relationship of the mean G.P.A. is not nonlinear. Since the F-ratio for the linear trend of the mean scores of the I.Q. (8.99), the Iowa Percentile (5.07), and the G.P.A. (6.95) were all above the .05 level of probability (3.84), Null Hypotheses (1), (3), and (5) were rejected. With respect to significant deviations from this linear trend, the F-ratio indicated that the mean scores for the I.Q. (.13), the Iowa Percentile (.13), and the G.P.A. (.48) were all below the .05 level of probability (2.21). Therefore, Null Hypotheses (2), (4), and (6) were accepted. Among the more important findings from this study are: 1. Both demand for and availability of "enrichment" and "advanced" courses, as compared to "remedial" courses, increased during the seven-year period. 2. There was a statistically significant upward linear trend, without significant deviations, in the mean scores of the I.Q., the Iowa Percentile, and the G.P.A. during the years 1956 through 1962. Thus, since the mean scores for each of the three variables were on a linear trend with a nonzero slope over the designated years; and since there were no significant deviations from the linear trend; and further, since inspection of tabulated data revealed a steady, if unspectacular, upward trend in all variables over the seven-year period under study, it seems reasonable to conclude that the summer session student in 1962 exhibited a scholastic background and an academic ability superior to those of his counterpart in 1956. Certain implications grow from these findings: 1. To meet the changing needs of learners, the summer school should periodically re-evaluate its curriculum. 2. In view of the dynamic growth of summer school and the complexity of its course offerings, more guidance is needed in assisting students to plan for summer school. 3. Since recent summer school enrollments have increased by such large numbers, an adequate plan for financing the summer school program is urgently needed. Title: Changes in the scholastic background and academic ability of summer school students in the Santa Monica, California, junior high schools is from 1956 to 1962 Author: Verge, Arthur Charles The purpose of this study was to investigate whether or not change has occurred in the scholastic background and academic ability of students attending the junior high school summer sessions of the Santa Monica Unified School District, California, between the years 1956 and 1962. Applying a Fisher and Yates Table of Randomized Numbers to the total summer school population in each of the years between and including 1956 and 1962, a random selection of 250 students from each year was made. The 1750 students' I.Q. scores, their Iowa Percentile scores, and their Grade Point Averages in the basic yearly subject grades comprised the three variables upon which the statistical analysis was based. Preliminary computations revealed that the means of the three variables generally (15 times out of 18) increased over those of the previous year during 1956 through 1962, and the standard deviation of the various distributions generally remained similar. To determine whether there was a significant linear trend during the years under study and, if so, whether any deviations from that trend were significant, a test of linear regression was applied to the following null hypotheses: scores. (1) There is no linear trend exhibited by the mean I.Q. (2) The relationship of the mean I.Q. scores is not nonlinear. (3) There is no linear trend exhibited by the mean of the Iowa Percentile scores. (4) The relationship of the mean Iowa Percentile scores is not nonlinear. (5) There is no linear trend exhibited by the mean G.P.A. (6) The relationship of the mean G.P.A. is not nonlinear. Since the F-ratio for the linear trend of the mean scores of the I.Q. (8.99), the Iowa Percentile (5.07), and the G.P.A. (6.95) were all above the .05 level of probability (3.84), Null Hypotheses (1), (3), and (5) were rejected. With respect to significant deviations from this linear trend, the F-ratio indicated that the mean scores for the I.Q. (.13), the Iowa Percentile (.13), and the G.P.A. (.48) were all below the .05 level of probability (2.21). Therefore, Null Hypotheses (2), (4), and (6) were accepted. Among the more important findings from this study are: 1. Both demand for and availability of "enrichment" and "advanced" courses, as compared to "remedial" courses, increased during the seven-year period. 2. There was a statistically significant upward linear trend, without significant deviations, in the mean scores of the I.Q., the Iowa Percentile, and the G.P.A. during the years 1956 through 1962. Thus, since the mean scores for each of the three variables were on a linear trend with a nonzero slope over the designated years; and since there were no significant deviations from the linear trend; and further, since inspection of tabulated data revealed a steady, if unspectacular, upward trend in all variables over the seven-year period under study, it seems reasonable to conclude that the summer session student in 1962 exhibited a scholastic background and an academic ability superior to those of his counterpart in 1956. Certain implications grow from these findings: 1. To meet the changing needs of learners, the summer school should periodically re-evaluate its curriculum. 2. In view of the dynamic growth of summer school and the complexity of its course offerings, more guidance is needed in assisting students to plan for summer school. 3. Since recent summer school enrollments have increased by such large numbers, an adequate plan for financing the summer school program is urgently needed. Close