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• 8081. [Article] Soil compaction and disturbance following a thinning of second-growth Douglas-fir with a cut-to-length and a skyline system in the Oregon Cascades

  Graduation date: 1998

  Citation × Citation Citation Abstract Copy Title: Soil compaction and disturbance following a thinning of second-growth Douglas-fir with a cut-to-length and a skyline system in the Oregon Cascades Author: Allen, Marganne Mary Graduation date: 1998 Title: Soil compaction and disturbance following a thinning of second-growth Douglas-fir with a cut-to-length and a skyline system in the Oregon Cascades Author: Allen, Marganne Mary Graduation date: 1998 Close

• 8082. [Article] Science and efficacy of mild sodium hydroxide treatments in enzyme-based wheat straw-to-glucose processing

  The work described in this dissertation focused on chemistry related to the use of aqueous sodium hydroxide as a treatment in the processing of wheat straw. A major emphasis was the comprehensive evaluation ...

  Citation × Citation Citation Abstract Copy Title: Science and efficacy of mild sodium hydroxide treatments in enzyme-based wheat straw-to-glucose processing Author: Sophonputtanaphoca, Supaporn The work described in this dissertation focused on chemistry related to the use of aqueous sodium hydroxide as a treatment in the processing of wheat straw. A major emphasis was the comprehensive evaluation of straw component partitioning due to sodium hydroxide (NaOH) processing. This was evaluated over a range of NaOH concentrations (0­‐10%, w/v), all at 50°C, 5 h treatment period, and 3% solid loading. Solid and liquid phases resulting from NaOH treatments were evaluated. Total solids recovered in the NaOH­‐treated solid phase ranged from 47.4­‐88.0%. Overall carbohydrate recovery in the combined solid and liquid phases was negatively correlated with the alkali concentration of the treatment liquor. The glucan content of the NaOH‐treated solid phase ranged from 37.2­‐67.4%. Glucan recovery in the solid phase was relatively high in all cases, the minimum value being ~98%. Increasing amounts of xylan partitioned into the liquid phase as sodium hydroxide concentrations increased – it ranged from 31­‐83% of the xylan being recovered in the soluble phase. Carbohydrate analyses of the pretreated liquor revealed that the majority of carbohydrate loss from the solid fraction could be recovered in the liquid phase in form of oligomers and monomers due to alkaline degradation. The interconversion of glucose, fructose, and mannose under the alkaline condition played an important role in the presence of those sugars. Increase in NaOH concentration contributed to increase in amount of cellulose­‐derived and hemicellulose‐derived oligomers in the pretreated liquor. All oligomers except fructooligomers in NaOH pretreated liquor were higher than those found in water extraction at 50°C, 5 h. Total carbohydrate recovery from the solid and liquid fractions was as high as 99% for glucose and glucan in 5% NaOH treatment and 80‐95% for xylose and xylan in 1-­10% NaOH treatment. The presence of NaOH as extraction reagent dramatically induced lignin and ash removal from the pretreated solid with up to 63% acid insoluble lignin (AIL) and 87% ash extraction. Solid fractions resulting from NaOH pretreatments (up to 5% NaOH) were tested for their susceptibility to enzymatic saccharification using cellulase and cellulase/xylanase enzyme preparations. The cellulase/xylanase enzyme preparation was found to be more effective at cellulose saccharification than the cellulase enzyme preparation alone. Maximum glucose yield, which corresponded to the 5% NaOH treatment, was 82% over the standard 48 h saccharification period. Extended saccharifications times to 120 h showed that the conversion yield approached 90%. Sequential treatments of the straw (i.e. initial alkali treatment – first enzyme saccharification – second alkali treatment ‐ second enzyme treatment) revealed the NaOH treatment has the potential to render essentially all (~99%) of the straw glucan susceptible to enzyme saccharification. This suggests that the layered molecular arrangement of cellulose, hemicellulose, and lignin in the cell wall impacts biomass recalcitrance and glucan conversion yield. The other major focus of this dissertation research was the characterization of alkali neutralization, which occurs during the aqueous alkali processing of wheat straw. The approach taken was to evaluate the time course of alkali uptake and to determine the underlying nature of alkali uptake. The knowledge generated from this study is useful for understanding the nature of the alkali‐induced chemistry that is at the heart of alkali processing of agricultural byproducts, foods, and forest products. Alkali uptake/acid generation measurements were monitored for wheat straw suspensions at pH 11 and 30°C. The first phase of alkali uptake corresponded to the 30‐second time period over which the pH of the wheat straw suspension was adjusted from its original pH (~6.6) to pH 11. Alkali neutralization during this period was attributed to the instantaneous ionization of solvent accessible Bronstad acids. Following pH adjustment to 11.0, the time course of subsequent alkali uptake was recorded. The time course appeared biphasic. The early phase, which corresponded to the relatively rapid uptake of alkali, was evident during the first 24 hours. The later phase, which was characterized by the relatively slow uptake of alkali, was maintained for the length of the study (up to 96 hours). Alkali uptake during the early phase of the time course appears to be determined by the rate of hydrolysis of readily accessible esters – primarily acetic acid esters (acetyl groups). Alkali uptake during the later phase of the time course appears to be impacted by the rate of alkali penetration into the straw and the rate of production of alkali‐induced acid degradation products. The uptake of alkali in the pH adjustment phase was ~ 120 μEq per gram wheat straw, the uptake of alkali in the early phase of time course was ~ 1,064 μEq per gram wheat straw, and the rate of uptake in the later phase of the time course 6.10 μEq per gram wheat straw per hour. Amount of acetyl groups, ferulic acid, and p-­coumaric acid generated during 96-­h pretreatment revealed that they are major esters being hydrolyzed under the studied condition. Combined, these ester-­derived acids contributed up to ~ 28% of overall alkali uptake. In addition, alkaline degradation products quantified in this study showed additional ~ 28% contribution to the overall alkali uptake. Title: Science and efficacy of mild sodium hydroxide treatments in enzyme-based wheat straw-to-glucose processing Author: Sophonputtanaphoca, Supaporn The work described in this dissertation focused on chemistry related to the use of aqueous sodium hydroxide as a treatment in the processing of wheat straw. A major emphasis was the comprehensive evaluation of straw component partitioning due to sodium hydroxide (NaOH) processing. This was evaluated over a range of NaOH concentrations (0­‐10%, w/v), all at 50°C, 5 h treatment period, and 3% solid loading. Solid and liquid phases resulting from NaOH treatments were evaluated. Total solids recovered in the NaOH­‐treated solid phase ranged from 47.4­‐88.0%. Overall carbohydrate recovery in the combined solid and liquid phases was negatively correlated with the alkali concentration of the treatment liquor. The glucan content of the NaOH‐treated solid phase ranged from 37.2­‐67.4%. Glucan recovery in the solid phase was relatively high in all cases, the minimum value being ~98%. Increasing amounts of xylan partitioned into the liquid phase as sodium hydroxide concentrations increased – it ranged from 31­‐83% of the xylan being recovered in the soluble phase. Carbohydrate analyses of the pretreated liquor revealed that the majority of carbohydrate loss from the solid fraction could be recovered in the liquid phase in form of oligomers and monomers due to alkaline degradation. The interconversion of glucose, fructose, and mannose under the alkaline condition played an important role in the presence of those sugars. Increase in NaOH concentration contributed to increase in amount of cellulose­‐derived and hemicellulose‐derived oligomers in the pretreated liquor. All oligomers except fructooligomers in NaOH pretreated liquor were higher than those found in water extraction at 50°C, 5 h. Total carbohydrate recovery from the solid and liquid fractions was as high as 99% for glucose and glucan in 5% NaOH treatment and 80‐95% for xylose and xylan in 1-­10% NaOH treatment. The presence of NaOH as extraction reagent dramatically induced lignin and ash removal from the pretreated solid with up to 63% acid insoluble lignin (AIL) and 87% ash extraction. Solid fractions resulting from NaOH pretreatments (up to 5% NaOH) were tested for their susceptibility to enzymatic saccharification using cellulase and cellulase/xylanase enzyme preparations. The cellulase/xylanase enzyme preparation was found to be more effective at cellulose saccharification than the cellulase enzyme preparation alone. Maximum glucose yield, which corresponded to the 5% NaOH treatment, was 82% over the standard 48 h saccharification period. Extended saccharifications times to 120 h showed that the conversion yield approached 90%. Sequential treatments of the straw (i.e. initial alkali treatment – first enzyme saccharification – second alkali treatment ‐ second enzyme treatment) revealed the NaOH treatment has the potential to render essentially all (~99%) of the straw glucan susceptible to enzyme saccharification. This suggests that the layered molecular arrangement of cellulose, hemicellulose, and lignin in the cell wall impacts biomass recalcitrance and glucan conversion yield. The other major focus of this dissertation research was the characterization of alkali neutralization, which occurs during the aqueous alkali processing of wheat straw. The approach taken was to evaluate the time course of alkali uptake and to determine the underlying nature of alkali uptake. The knowledge generated from this study is useful for understanding the nature of the alkali‐induced chemistry that is at the heart of alkali processing of agricultural byproducts, foods, and forest products. Alkali uptake/acid generation measurements were monitored for wheat straw suspensions at pH 11 and 30°C. The first phase of alkali uptake corresponded to the 30‐second time period over which the pH of the wheat straw suspension was adjusted from its original pH (~6.6) to pH 11. Alkali neutralization during this period was attributed to the instantaneous ionization of solvent accessible Bronstad acids. Following pH adjustment to 11.0, the time course of subsequent alkali uptake was recorded. The time course appeared biphasic. The early phase, which corresponded to the relatively rapid uptake of alkali, was evident during the first 24 hours. The later phase, which was characterized by the relatively slow uptake of alkali, was maintained for the length of the study (up to 96 hours). Alkali uptake during the early phase of the time course appears to be determined by the rate of hydrolysis of readily accessible esters – primarily acetic acid esters (acetyl groups). Alkali uptake during the later phase of the time course appears to be impacted by the rate of alkali penetration into the straw and the rate of production of alkali‐induced acid degradation products. The uptake of alkali in the pH adjustment phase was ~ 120 μEq per gram wheat straw, the uptake of alkali in the early phase of time course was ~ 1,064 μEq per gram wheat straw, and the rate of uptake in the later phase of the time course 6.10 μEq per gram wheat straw per hour. Amount of acetyl groups, ferulic acid, and p-­coumaric acid generated during 96-­h pretreatment revealed that they are major esters being hydrolyzed under the studied condition. Combined, these ester-­derived acids contributed up to ~ 28% of overall alkali uptake. In addition, alkaline degradation products quantified in this study showed additional ~ 28% contribution to the overall alkali uptake. Close

• 8083. [Article] Population Genetics of American Pika (Ochotona princeps) : Investigating Gene Flow and Genetic Diversity Across Multiple, Complex Landscapes

  American pikas (Ochotona princeps) are considered an indicator species of climate change. Adaptations for cold climates and active winters make pikas particularly sensitive to increasing temperatures. ...

  Citation × Citation Citation Abstract Copy Title: Population Genetics of American Pika (Ochotona princeps) : Investigating Gene Flow and Genetic Diversity Across Multiple, Complex Landscapes Author: Castillo, Jessica A. American pikas (Ochotona princeps) are considered an indicator species of climate change. Adaptations for cold climates and active winters make pikas particularly sensitive to increasing temperatures. This, combined with evidence that multiple historically occupied populations have been extirpated within the past century, contributed to American pikas becoming a focal species for climate change research. This dissertation is primarily the product of a collaboration among the National Parks Service and multiple academic institutions whose principal goal was to assess the vulnerability of the American pika within eight national parks representing a variety of habitat types and environmental conditions. While much of the previous climate change-related research on American pikas has focused on how climate affects occupancy, this work sought to establish how landscape characteristics and climate may interact and influence dispersal, population connectivity, and ultimately population vulnerability or resilience. I addressed these questions using population and landscape genetics approaches within nine national parks, two national wildlife refuges, and a national forest. American pikas represent one of the best described mammalian metapopulation systems. They are restricted to rocky habitats, such as talus and lava, which are frequently patchily distributed on the landscape, both at the local and regional scales. Functional connectivity, the combination of habitat configuration and an organism’s ability to move through the landscape, is essential for maintaining robust genetic populations. This is particularly true within metapopulations which, by definition, rely on dispersal of individuals among habitat patches for overall long-term stability. In Chapters 1 and 2, I used a landscape genetics approach to identify features that either promote or inhibit dispersal of American pikas. There has been significant debate over the past few years about the best statistical approaches within landscape genetics and the appropriateness of certain methods in particular. In Chapter 1, I used Crater Lake National Park as a test case to evaluate the effectiveness of Mantel and partial Mantel tests in a causal modeling framework to correctly identify underlying landscape variables (e.g., topography, aspect, water barriers) and their effect on gene flow. I demonstrated, through simulations, that this approach was able to correctly identify the landscape variables, but not precisely the magnitude of their effect on gene flow. I concluded that while results need to be interpreted with caution, this method was effective for identifying which variables are important in shaping functional connectivity. In Chapter 2, I applied the causal modeling approach from Chapter 1 to seven additional study sites. I identified a general trend that south-west facing aspects pose greater resistance to dispersal than north and east-facing aspects, suggesting that exposure to high temperatures may limit dispersal in American pikas. I also found that amount and configuration of habitat (i.e., rocky substrate) influenced the degree to which other landscape variables impact dispersal. I then applied the models of landscape resistance to investigate habitat patch connectivity within each site using a graph theoretic approach. This allowed me to assess overall patch connectivity, as well as identify specific patches and areas within study sites that are particularly important for maintaining functional connectivity, or in contrast, at risk of becoming isolated. Functional connectivity is an important component when assessing population vulnerability because it describes the ability of genetic material to flow through the landscape. A loss of gene flow can lead to isolation of population segments, reduction of effective population size, loss of genetic diversity and subsequent erosion of evolutionary potential, and ultimately metapopulation collapse. However, other factors including habitat area and quality, affect effective population size and population stability. Genetic diversity is the material upon which evolution acts. In the face of rapid environmental change, species must either shift their range in order to track their ecological niche, or adapt in situ to the new environment. The former strategy requires sufficient available habitat as well as dispersal ability, which is unlikely for American pikas. Genetic diversity, therefore, is an important indicator of long-term population viability. In Chapter 3, I quantified genetic diversity within thirteen study sites and investigated the relationship between genetic diversity and environmental variables related to climate as well as habitat configuration and quality. As expected, habitat area was important at both the local and regional scales. Temperature was also a significant predictor of genetic diversity, with hotter sites having lower genetic diversity. However, and somewhat surprisingly, precipitation was a better predictor of genetic diversity than temperature, with sites receiving moderate levels of precipitation having higher genetic diversity. I also compared population differentiation among study sites and identified sites that are particularly distinct. In the process of the above analyses, I also identified a previously undescribed contact zone between the northern and southern Rocky Mountain genetic lineages, recognized as separate subspecies, within Rocky Mountain National Park. Climate change is predicted to affect habitat quality and landscape permeability, both of which have detectable genetic consequences. In Chapter 4, I quantified genetic diversity and structure within two study sites, Yosemite and Lassen Volcanic National Parks, from two sampling periods separated by approximately a century in time. I extracted DNA from historic study skins housed in the University of California Berkeley Museum of Vertebrate Zoology (MVZ) and compared multilocus microsatellite genotypes to those generated from modern fecal and tissue samples. Additionally, the historic survey data, including specimens, field journals, and other artifacts, were used in a series of systematic resurveys and subsequent species distribution modelling by other researchers. The nature of national parks as protected areas affords the opportunity to isolate the effects of climate change to a greater degree than other areas that have also experienced significant land use changes. I found no evidence for a change in genetic diversity within these two sites, consistent with observations from other studies that occupancy has remained relatively stable. I did find some evidence suggesting increasing population differentiation, potentially as a result of eroding landscape permeability. These results provide an important baseline for comparison with other sites, as well as reference points for future genetic monitoring of these populations. In Chapter 5, I provide general synthesis and conclusions, as well as considerations for future research. Title: Population Genetics of American Pika (Ochotona princeps) : Investigating Gene Flow and Genetic Diversity Across Multiple, Complex Landscapes Author: Castillo, Jessica A. American pikas (Ochotona princeps) are considered an indicator species of climate change. Adaptations for cold climates and active winters make pikas particularly sensitive to increasing temperatures. This, combined with evidence that multiple historically occupied populations have been extirpated within the past century, contributed to American pikas becoming a focal species for climate change research. This dissertation is primarily the product of a collaboration among the National Parks Service and multiple academic institutions whose principal goal was to assess the vulnerability of the American pika within eight national parks representing a variety of habitat types and environmental conditions. While much of the previous climate change-related research on American pikas has focused on how climate affects occupancy, this work sought to establish how landscape characteristics and climate may interact and influence dispersal, population connectivity, and ultimately population vulnerability or resilience. I addressed these questions using population and landscape genetics approaches within nine national parks, two national wildlife refuges, and a national forest. American pikas represent one of the best described mammalian metapopulation systems. They are restricted to rocky habitats, such as talus and lava, which are frequently patchily distributed on the landscape, both at the local and regional scales. Functional connectivity, the combination of habitat configuration and an organism’s ability to move through the landscape, is essential for maintaining robust genetic populations. This is particularly true within metapopulations which, by definition, rely on dispersal of individuals among habitat patches for overall long-term stability. In Chapters 1 and 2, I used a landscape genetics approach to identify features that either promote or inhibit dispersal of American pikas. There has been significant debate over the past few years about the best statistical approaches within landscape genetics and the appropriateness of certain methods in particular. In Chapter 1, I used Crater Lake National Park as a test case to evaluate the effectiveness of Mantel and partial Mantel tests in a causal modeling framework to correctly identify underlying landscape variables (e.g., topography, aspect, water barriers) and their effect on gene flow. I demonstrated, through simulations, that this approach was able to correctly identify the landscape variables, but not precisely the magnitude of their effect on gene flow. I concluded that while results need to be interpreted with caution, this method was effective for identifying which variables are important in shaping functional connectivity. In Chapter 2, I applied the causal modeling approach from Chapter 1 to seven additional study sites. I identified a general trend that south-west facing aspects pose greater resistance to dispersal than north and east-facing aspects, suggesting that exposure to high temperatures may limit dispersal in American pikas. I also found that amount and configuration of habitat (i.e., rocky substrate) influenced the degree to which other landscape variables impact dispersal. I then applied the models of landscape resistance to investigate habitat patch connectivity within each site using a graph theoretic approach. This allowed me to assess overall patch connectivity, as well as identify specific patches and areas within study sites that are particularly important for maintaining functional connectivity, or in contrast, at risk of becoming isolated. Functional connectivity is an important component when assessing population vulnerability because it describes the ability of genetic material to flow through the landscape. A loss of gene flow can lead to isolation of population segments, reduction of effective population size, loss of genetic diversity and subsequent erosion of evolutionary potential, and ultimately metapopulation collapse. However, other factors including habitat area and quality, affect effective population size and population stability. Genetic diversity is the material upon which evolution acts. In the face of rapid environmental change, species must either shift their range in order to track their ecological niche, or adapt in situ to the new environment. The former strategy requires sufficient available habitat as well as dispersal ability, which is unlikely for American pikas. Genetic diversity, therefore, is an important indicator of long-term population viability. In Chapter 3, I quantified genetic diversity within thirteen study sites and investigated the relationship between genetic diversity and environmental variables related to climate as well as habitat configuration and quality. As expected, habitat area was important at both the local and regional scales. Temperature was also a significant predictor of genetic diversity, with hotter sites having lower genetic diversity. However, and somewhat surprisingly, precipitation was a better predictor of genetic diversity than temperature, with sites receiving moderate levels of precipitation having higher genetic diversity. I also compared population differentiation among study sites and identified sites that are particularly distinct. In the process of the above analyses, I also identified a previously undescribed contact zone between the northern and southern Rocky Mountain genetic lineages, recognized as separate subspecies, within Rocky Mountain National Park. Climate change is predicted to affect habitat quality and landscape permeability, both of which have detectable genetic consequences. In Chapter 4, I quantified genetic diversity and structure within two study sites, Yosemite and Lassen Volcanic National Parks, from two sampling periods separated by approximately a century in time. I extracted DNA from historic study skins housed in the University of California Berkeley Museum of Vertebrate Zoology (MVZ) and compared multilocus microsatellite genotypes to those generated from modern fecal and tissue samples. Additionally, the historic survey data, including specimens, field journals, and other artifacts, were used in a series of systematic resurveys and subsequent species distribution modelling by other researchers. The nature of national parks as protected areas affords the opportunity to isolate the effects of climate change to a greater degree than other areas that have also experienced significant land use changes. I found no evidence for a change in genetic diversity within these two sites, consistent with observations from other studies that occupancy has remained relatively stable. I did find some evidence suggesting increasing population differentiation, potentially as a result of eroding landscape permeability. These results provide an important baseline for comparison with other sites, as well as reference points for future genetic monitoring of these populations. In Chapter 5, I provide general synthesis and conclusions, as well as considerations for future research. Close

• 8084. [Article] Urban natural parks in Portland : nature, networks, and community health

  Three trends are occurring today in the United States which inspired this research. First, America is growing increasingly urbanized. Today, more Americans are living in cities than in rural environments, ...

  Citation × Citation Citation Abstract Copy Title: Urban natural parks in Portland : nature, networks, and community health Author: Baur, Joshua W. R. Three trends are occurring today in the United States which inspired this research. First, America is growing increasingly urbanized. Today, more Americans are living in cities than in rural environments, and this pattern is predicted to continue for the foreseeable future. Urban living has benefits, but there are also challenges for city residents including pollution, traffic, and crime. As social scientists, we need to improve our understanding of urban dwellers' relationship with their natural environment just as biophysical scientists are focusing more and more on the impacts of urban development on the natural world. Second, Americans are spending less time recreating outdoors. There has been a documented decline of participation in nature-based recreation, likely being replaced by an increase in use of electronic media during people's leisure time. Less contact with nature has consequences for people, perhaps especially for city dwellers who spend the majority of their time surrounded by the built environment of concrete and asphalt. It is likely that reliance on electronic entertainment has played a substantial role in decreasing amounts of physical activity. Lastly, Americans are becoming more sedentary. Today, the number of Americans who report getting no physical activity is about equal to the number who report getting regular physical exercise during their free time. Rising rates of obesity for adults and children in the U.S. have raised considerable concerns among medical and public policy professionals. The purpose of this research was to examine how small-scale urban nature parks are affecting city residents in Portland, OR. I looked at three elements of Portland residents' relationship with urban nature parks. First, I looked at whether there was an association between individual physical and psychological health and park use. Prior research has revealed that people who spend time recreating outdoors tend to be more physically active than people who do not. These observed higher levels of physical activity are associated with improved physical health. Time in nature settings has also demonstrated a positive effect on psychological well-being, such as reduced anxiety and improved ability to concentrate. Second, I examined whether having a nature park in their community had an effect on Portland residents' sense of neighborhood health. Previous research suggests that having natural areas in urbanized areas directly contributes to city residents' sense of a stronger, healthier community. Green space in cities has been associated with not only higher levels of reported satisfaction with the neighborhood, but also with higher property values, and with higher levels of retail spending. Third, I employed a social psychological model of attitude formation to evaluate Portland residents' attitudes about their nature parks. Attitudes are particularly important for natural resource managers to understand and account for in policy decisions since management of natural resources often engages the public's sense of personal freedoms and concerns over government regulations. Furthermore, because people in cities are so closely in contact with urban green space on a regular basis, inclusive and responsive policy requires that managers take account of public attitudes. I collected the data relating to these three elements of the relationship between urban residents and their nature parks in Portland because it is the largest city in Oregon. I obtained the data through a general population survey, randomly distributed to residents in the Portland metropolitan area during the fall of 2010. I conducted customary social science statistical analysis, including linear regression, to assess the relationship between Portland nature parks and personal and community health. To evaluate my sample's attitudes, I used the tripartite model of attitude formation originally developed in social psychology research. Because I was working with latent factors of attitude formation, I used structural equation modeling to assess the relationship of the observed variables to their latent factors, and the relationship among the latent factors. My results largely agree with those of other researchers, though I approached the question of physical health and nature recreation slightly differently. For my work on physical health, rather than ask about physical activity and infer health outcomes, I asked directly about physical health. I tested two hypotheses. One hypothesis was that there would be a positive association between self-reported physical health and park use, and the other tested for a positive association between park use and psychological health. My hypothesis for the physical health-parks relationship was partially supported. I tested two physical health variables, and found that one, which described overall health, did reveal a statistically significant relationship to park use. The other, relating to role limitations due to physical health problems, did not have a significant relationship to park use. My second hypothesis asserted that there would be a positive relationship between psychological health and park user status. This hypothesis was not supported, but I did find indications of an association between psychological health and park use. The second element of the relationship between city residents and urban nature parks related to neighborhood health. My results from this analysis were consistent with prior research findings which tend to support a positive association. I tested whether parks close by respondents homes (a fifteen to twenty minute walk), and parks farther away (no more than a ten minute drive away from home) were positively associated with self-reported neighborhood health. I found that both levels of proximity were positively associated with perceptions of neighborhood health. Because prior research suggests that one of the ways that neighborhood green spaces promote stronger communities is through the social interactions that occur in parks among neighbors, I also tested whether park-related social interaction was positively associated with community health ratings. In testing for a mediating effect of social interaction on the relationship between parks and neighborhood health, I found that park-related social interaction had a partial mediating effect on neighborhood health ratings for both parks within walking distance and within driving distance. In testing for moderation, I found that the moderation effect of social interaction was present only for parks within walking distance. The third and final element of the relationship between urban nature parks and city dwellers was attitudes about urban nature parks. I employed a model of attitude formation originally proposed in the social psychology literature. The tripartite model argues that an attitude is formed through three precursors: the cognitive, the affective, and the behavioral components. I also included an additional variable for social networks which I proposed would act as a moderating variable on the relationship between the other components and park attitude. My results for the entire, combined sample of both park users and nonusers indicated that both the cognitive factor and the affective factor have a significant association with attitude formation, while the behavioral component did not. The model for the combined sample also showed that social networks had a statistically significant, inverse relationship with attitudes. I conducted a test for attitude differences between groups (users and nonusers), and found a statistically significant difference. I also tested for a moderating effect of social networks on the other attitude formation components, but that relationship was not supported. Finally, I conducted comparisons between the two groups to assess any differences in the attitude components between users and nonusers. Side-by-side comparisons revealed that both users' and nonusers' attitudes were significantly influenced by the affective component. Perceived outcomes of park use was not predictive of attitude for either group. The values component (on an anthropocentric-biocentric scale) was significant for users, but not nonusers. Nonusers attitudes were also significantly impacted by the behavioral component (i.e., behaviors related to parks), and by social networks. Social networks were not predictive of users' park attitudes. The research I have presented herein provides support for the hypotheses that time spent in natural settings is associated with better physical and psychological health and that community green spaces contribute to satisfaction with one's neighborhood. I also found that attitudes about parks differed between users and nonusers, yet both groups valued them as benefits in the urban environment. Since my sample size was insufficient to make generalizable statements about Portland's population, my results are suggestive, but are consistent with prior research. My research results can help urban natural resource managers and city decision-makers make more inclusive decisions by incorporating an understanding of city residents' relationships to urban nature parks. The results of my research on personal and community health support the position that urban green space fulfills an important function by providing valuable public health benefits, and promoting healthier, more "livable" communities. My results indicate that, for my sample, social interaction at parks was positively related to neighborhood health. Such a positive association suggests that parks could be leveraged to build community cohesion which ultimately leads to benefits like increased sense of safety and happier residents. My results pertaining to park attitudes can help managers develop more targeted public outreach campaigns. For instance, I found that for park nonusers, social networks were a statistically significant predictor of park attitudes. This result implies that park staff and managers could benefit by identifying community organizations and business associations that might be conduits to reach nonusers. Through such information pathways, park managers could disseminate information about urban nature parks that could attract current nonusers. Urban nature parks are not the sole answer to building healthier communities and people. They cannot alone reverse social ills that many urban neighborhoods contend with routinely. However, the scientific data do support the idea that urban natural spaces like nature parks are positively associated with personal and community health. With careful participatory planning that includes a substantial public input component, urban natural resource managers could develop urban nature parks as part of a city's green infrastructure that not only provides valuable ecosystem services like cleaner water and reduced energy consumption, but also provides for nature-based recreation experiences that promote healthier, happier city residents. Title: Urban natural parks in Portland : nature, networks, and community health Author: Baur, Joshua W. R. Three trends are occurring today in the United States which inspired this research. First, America is growing increasingly urbanized. Today, more Americans are living in cities than in rural environments, and this pattern is predicted to continue for the foreseeable future. Urban living has benefits, but there are also challenges for city residents including pollution, traffic, and crime. As social scientists, we need to improve our understanding of urban dwellers' relationship with their natural environment just as biophysical scientists are focusing more and more on the impacts of urban development on the natural world. Second, Americans are spending less time recreating outdoors. There has been a documented decline of participation in nature-based recreation, likely being replaced by an increase in use of electronic media during people's leisure time. Less contact with nature has consequences for people, perhaps especially for city dwellers who spend the majority of their time surrounded by the built environment of concrete and asphalt. It is likely that reliance on electronic entertainment has played a substantial role in decreasing amounts of physical activity. Lastly, Americans are becoming more sedentary. Today, the number of Americans who report getting no physical activity is about equal to the number who report getting regular physical exercise during their free time. Rising rates of obesity for adults and children in the U.S. have raised considerable concerns among medical and public policy professionals. The purpose of this research was to examine how small-scale urban nature parks are affecting city residents in Portland, OR. I looked at three elements of Portland residents' relationship with urban nature parks. First, I looked at whether there was an association between individual physical and psychological health and park use. Prior research has revealed that people who spend time recreating outdoors tend to be more physically active than people who do not. These observed higher levels of physical activity are associated with improved physical health. Time in nature settings has also demonstrated a positive effect on psychological well-being, such as reduced anxiety and improved ability to concentrate. Second, I examined whether having a nature park in their community had an effect on Portland residents' sense of neighborhood health. Previous research suggests that having natural areas in urbanized areas directly contributes to city residents' sense of a stronger, healthier community. Green space in cities has been associated with not only higher levels of reported satisfaction with the neighborhood, but also with higher property values, and with higher levels of retail spending. Third, I employed a social psychological model of attitude formation to evaluate Portland residents' attitudes about their nature parks. Attitudes are particularly important for natural resource managers to understand and account for in policy decisions since management of natural resources often engages the public's sense of personal freedoms and concerns over government regulations. Furthermore, because people in cities are so closely in contact with urban green space on a regular basis, inclusive and responsive policy requires that managers take account of public attitudes. I collected the data relating to these three elements of the relationship between urban residents and their nature parks in Portland because it is the largest city in Oregon. I obtained the data through a general population survey, randomly distributed to residents in the Portland metropolitan area during the fall of 2010. I conducted customary social science statistical analysis, including linear regression, to assess the relationship between Portland nature parks and personal and community health. To evaluate my sample's attitudes, I used the tripartite model of attitude formation originally developed in social psychology research. Because I was working with latent factors of attitude formation, I used structural equation modeling to assess the relationship of the observed variables to their latent factors, and the relationship among the latent factors. My results largely agree with those of other researchers, though I approached the question of physical health and nature recreation slightly differently. For my work on physical health, rather than ask about physical activity and infer health outcomes, I asked directly about physical health. I tested two hypotheses. One hypothesis was that there would be a positive association between self-reported physical health and park use, and the other tested for a positive association between park use and psychological health. My hypothesis for the physical health-parks relationship was partially supported. I tested two physical health variables, and found that one, which described overall health, did reveal a statistically significant relationship to park use. The other, relating to role limitations due to physical health problems, did not have a significant relationship to park use. My second hypothesis asserted that there would be a positive relationship between psychological health and park user status. This hypothesis was not supported, but I did find indications of an association between psychological health and park use. The second element of the relationship between city residents and urban nature parks related to neighborhood health. My results from this analysis were consistent with prior research findings which tend to support a positive association. I tested whether parks close by respondents homes (a fifteen to twenty minute walk), and parks farther away (no more than a ten minute drive away from home) were positively associated with self-reported neighborhood health. I found that both levels of proximity were positively associated with perceptions of neighborhood health. Because prior research suggests that one of the ways that neighborhood green spaces promote stronger communities is through the social interactions that occur in parks among neighbors, I also tested whether park-related social interaction was positively associated with community health ratings. In testing for a mediating effect of social interaction on the relationship between parks and neighborhood health, I found that park-related social interaction had a partial mediating effect on neighborhood health ratings for both parks within walking distance and within driving distance. In testing for moderation, I found that the moderation effect of social interaction was present only for parks within walking distance. The third and final element of the relationship between urban nature parks and city dwellers was attitudes about urban nature parks. I employed a model of attitude formation originally proposed in the social psychology literature. The tripartite model argues that an attitude is formed through three precursors: the cognitive, the affective, and the behavioral components. I also included an additional variable for social networks which I proposed would act as a moderating variable on the relationship between the other components and park attitude. My results for the entire, combined sample of both park users and nonusers indicated that both the cognitive factor and the affective factor have a significant association with attitude formation, while the behavioral component did not. The model for the combined sample also showed that social networks had a statistically significant, inverse relationship with attitudes. I conducted a test for attitude differences between groups (users and nonusers), and found a statistically significant difference. I also tested for a moderating effect of social networks on the other attitude formation components, but that relationship was not supported. Finally, I conducted comparisons between the two groups to assess any differences in the attitude components between users and nonusers. Side-by-side comparisons revealed that both users' and nonusers' attitudes were significantly influenced by the affective component. Perceived outcomes of park use was not predictive of attitude for either group. The values component (on an anthropocentric-biocentric scale) was significant for users, but not nonusers. Nonusers attitudes were also significantly impacted by the behavioral component (i.e., behaviors related to parks), and by social networks. Social networks were not predictive of users' park attitudes. The research I have presented herein provides support for the hypotheses that time spent in natural settings is associated with better physical and psychological health and that community green spaces contribute to satisfaction with one's neighborhood. I also found that attitudes about parks differed between users and nonusers, yet both groups valued them as benefits in the urban environment. Since my sample size was insufficient to make generalizable statements about Portland's population, my results are suggestive, but are consistent with prior research. My research results can help urban natural resource managers and city decision-makers make more inclusive decisions by incorporating an understanding of city residents' relationships to urban nature parks. The results of my research on personal and community health support the position that urban green space fulfills an important function by providing valuable public health benefits, and promoting healthier, more "livable" communities. My results indicate that, for my sample, social interaction at parks was positively related to neighborhood health. Such a positive association suggests that parks could be leveraged to build community cohesion which ultimately leads to benefits like increased sense of safety and happier residents. My results pertaining to park attitudes can help managers develop more targeted public outreach campaigns. For instance, I found that for park nonusers, social networks were a statistically significant predictor of park attitudes. This result implies that park staff and managers could benefit by identifying community organizations and business associations that might be conduits to reach nonusers. Through such information pathways, park managers could disseminate information about urban nature parks that could attract current nonusers. Urban nature parks are not the sole answer to building healthier communities and people. They cannot alone reverse social ills that many urban neighborhoods contend with routinely. However, the scientific data do support the idea that urban natural spaces like nature parks are positively associated with personal and community health. With careful participatory planning that includes a substantial public input component, urban natural resource managers could develop urban nature parks as part of a city's green infrastructure that not only provides valuable ecosystem services like cleaner water and reduced energy consumption, but also provides for nature-based recreation experiences that promote healthier, happier city residents. Close

• 8085. [Article] Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles ; August 1984

  Improved Fumigants After 14 years, chloropicrin, Vapam and Vorlex continue to effectively control internal decay of pressure-treated Douglas-fir transmission poles, but 6 years after application of methylisothiocyanate (MIT) ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles ; August 1984 Author: Oregon State University, Oregon State University. Dept. of Forest Products Improved Fumigants After 14 years, chloropicrin, Vapam and Vorlex continue to effectively control internal decay of pressure-treated Douglas-fir transmission poles, but 6 years after application of methylisothiocyanate (MIT) some poles are becoming reinfested by decay fungi although NIT residues remain high in these poles. The closed-tube bioassay, developed through our research, is an effective method for detecting fumigant persistance, and future studies will aim at determining the actual fumigant concentrations detected in wood by this bioassay. A study of MIT movement through Douglas-fir pole sections following treatment with gelatin encapsulated MIT was completed and results indicate that addition of small quantities of water along with the capsules will give excellent fumigant release and movement into the wood. Decay fungi were virtually eliminated from in service transmission poles 21 months after treatment with gelatin encapsulated MIT near the groundline. In poles treated up to 12 feet above the groundline with encapsulated MIT and chloropicrin, no decay fungi could be isolated 1 year after treatment. Both fumigants were well distributed through the poles and appear to have moved laterally from the treatment holes. One of the goals of our research has been eventual fumigant application to poles at the treatment plant shortly after conventional preservative treatments. This would provide predrilled holes for later fumigant retreatment and would effectively protect the entire i iipole cross section. While the most economical application method would involve incorporating the fumigant treatment holes into the conventional predrilling process, it would also result in preservative treated fumigant holes. Consequently we have initiated studies to determine the influence of creosote and pentachlorophenol on fumigant movement into treated wood. Preliminary results indicate that creosote and P-9 penta base oil slow movement of MIT into wood but do not prevent the build up of fungitoxic concentrations in the wood. The new, pelletized MIT formulation has been evaluated in our laboratory assay for wood fumigants. The results indicate that pelletized MIT is as effective as pure MIT on an active ingredient basis. Since pelletized MIT has many similar application and safety advantages as encapsulated MIT, we intend to further evaluate pellets in poles in service. Cedar Sapwood Decay Control The effectiveness of seventeen chemicals (3 oil-borne, 14 water-borne) for controlling above-ground decay of cedar sapwood was evaluated using a modified soil block test and an Aspergillus bioassay. Pentachlorophenol (10%) in diesel oil, currently used for protecting cedar poles, was markedly superior to all other chemicals evaluated probably because of the increased penetrability of the oil, since penta in water at the same strength did not perform as well. Three other formulations, copper-8-quinolinolate (oil), pentachlorophenol (2% in water), and 3-iodo propynyl butyl carbamate (2% in water), exhibited some residual effectiveness; however, more time is necessary to determine if these chemicals will remain effective. An additional five chemicals will be evaluated this coming spring. iii The persistence of chloropicrin 5 years after treatment in western redcedar was also evaluated using open tube bioassays, closetube bioassays and gas chromatographic determinations. The open tube bioassay indicated that chioropicrin still effectively limited growth of the assay fungus, P. placenta. Similarly, closed tube bioassays indicated strong inhibition in the pole interior and lower inhibitions near the surface. Extraction/gas chromatographic procedures detected chloropicrin in all cores examined with the highest concentrations towards the pole interior. Chioropicrin concentration did not correlate with closed tube results, suggesting that these tests are measuring different fumigant properties. The results indicate that chloropicrin should be an effective treatment for preventing cedarbutt rot and may provide some protection to pole sapwood. Bolt Holes Control poles for the bolt hole protection study were again sampled and insufficient decay was found in these poles to warrant evaluation of the various decay prevention treatments. We will reevaluate the control poles this summer. Detecting decay and estimating residual strength in poles An infrared spectrophotometric method of analyzing warm water extracts of decayed and non-decay wood was evaluated with a number of brown and white rot fungi. Brown rot was highly correlated with absorption peaks produced at wavelength 17201cm. Work is now underway to identify this peak to determine if less involved detection methods might be employed. iv Fluorescent labeled lectins, which have high specificity for selected carbohydrates, were also evaluated as potential fungal indicators. Of the lectins tested, wheat germ agglutinin appears the most promising since it strongly reacted with chitin in the fungal cell wall, making decay hyphae visible at very early stages of decay. Evaluation of Douglas-fir beams air-seasoned for 1 or 2 years using Pilodyn pin penetration, longitudinal compression, radial compression, bending and culturing indicated that, while there is a well established fungal flora in the wood, this flora has not yet affected strength. These tests will be performed on the 3 year airseasoned beams this coming year. Of the strength tests employed, longitudinal compression appears promising for estimating pole bending strength and we intend to further evaluate this method. As a second phase of this evaluation, the effect of moisture content on Pilodyn pin penetration was examined. This information is necessary since pin penetration varies with moisture content and must be corrected to compare values from different poles. Pin penetration increased with increasing moisture content up to fiber saturation and stabilized above this point. The moisture content at 0.5 inches was highly correlated with pin penetration, and this depth might be a convenient standard measuring point. En a new phase of the project, preliminary acoustic testing was begun using small beams from poles at varying stages of decay. These beams were sonically evaluated and then loaded to failure in three point bending tests. Sonic evaluation was highly correlated with NOR; however, much more testing will be necessary before such an apparatus can be applied to posts or poles. V Initiation of decay in Douglas-fir poles prior to pressure treatment The ability of basidiomycetes isolated from air-seasoning poles to reduce wood strength was evaluated in rapid tests for toughness by impact bending and changes in the breaking radius of Douglas-fir test wafers. Although some fungi behaved differently in the two tests, the test correlations were relatively high (r2 = O.78S). Of 26 basidiomycetous species evaluated, Poria placenta, P. carbonica, P. xantha and Crustoderma dryinum most rapidly decayed Douglas-fir heartwood, but at least one isolate of most of the other species tested significantly reduced toughness. While the wood decaying ability of each fungus is important, the frequency of isolation also must be considered when determining the overall importance of a species. To determine the influence of wood temperature and moisture content on establishment of P. carbonica in Douglas-fir heartwood, a method was developed for direct observation of germinating spores on wood. In this test, chiamydospores and basidiospores failed to germinate or colonize wood at moisture content below fiber saturation suggesting that free water is necessary for infection. Chiamydospores germinated most readily and colonized wood at 22°C, while germination was significantly lower and the fungus failed to become established in wood at 5 or 35°C. Similar temperature responses were obtained with basidiospores although these spores failed to germinate at 5 and 35°C. Nevertheless, basidiospores may remain viable and retain the potential to establish colonies once conditions become more favorable. vi Exposure of sterilized pole sections at four Pacific Northwest air-seasoning sites for successive 3-month periods showed a significant increase in basidiomycete isolation frequency for the period Nov. '81-Jan.'82. Furthermore, the frequency increased from the northern to the southern most site. Detailed study of the site weather patterns strongly suggests that increased basidiomycetous infection can be related to number of days with measurable rain fall and temperatures conducive to fungal growth. During the other periods studied, temperature or precipitation conditions were unfavorable for infection and pole section moisture contents fell below fiber saturation. This in turn limited spore germination and fungal colonization of the wood. About 30 different basidiomycetous species have been identified from isolates cultured from sterilized pole sections exposed at the four sites. In general, the species were the same as those isolated form air-seasoning poles although there were some significant differences between the species obtained from the different sites. The frequency of P. placenta mono- and dikaryons was particularly high with monokaryons more abundant at three of the four locations. Individual species exhibited distinct colonization patterns from different pole zones. For example, P. placenta was isolated most frequently from heartwood exposed at the pole ends while Peniophora spp. and llaemotostereum sanguinolentum were recovered most frequently from the upper surfaces of the pole sections. vii Preventing infection of poles by decay fungi during air-seasoning Pole sections treated with ammonium bifluoride (NH4HF2) or gelatin encapsulated MIT and chioropicrin were extensively sampled after air seasoning to determine the influence of these chemicals on wood colonization by decay fungi. Preliminary results indicate that after 2 years NH4HF2 and the fumigants significantly reduced basidiomycetous colonization of sterile wood. Surface Decay Poles treated with Vapam 14 years ago were extensively cored, the cores were cultured and the resulting fungi were identified to evaluate the fungal flora of fumigant treated wood. A well developed fungal flora was identified that differed from that found in nonfumigant treated wood. These fungi will be further evaluated to determine their role in fumigant effectiveness. Title: Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles ; August 1984 Author: Oregon State University, Oregon State University. Dept. of Forest Products Improved Fumigants After 14 years, chloropicrin, Vapam and Vorlex continue to effectively control internal decay of pressure-treated Douglas-fir transmission poles, but 6 years after application of methylisothiocyanate (MIT) some poles are becoming reinfested by decay fungi although NIT residues remain high in these poles. The closed-tube bioassay, developed through our research, is an effective method for detecting fumigant persistance, and future studies will aim at determining the actual fumigant concentrations detected in wood by this bioassay. A study of MIT movement through Douglas-fir pole sections following treatment with gelatin encapsulated MIT was completed and results indicate that addition of small quantities of water along with the capsules will give excellent fumigant release and movement into the wood. Decay fungi were virtually eliminated from in service transmission poles 21 months after treatment with gelatin encapsulated MIT near the groundline. In poles treated up to 12 feet above the groundline with encapsulated MIT and chloropicrin, no decay fungi could be isolated 1 year after treatment. Both fumigants were well distributed through the poles and appear to have moved laterally from the treatment holes. One of the goals of our research has been eventual fumigant application to poles at the treatment plant shortly after conventional preservative treatments. This would provide predrilled holes for later fumigant retreatment and would effectively protect the entire i iipole cross section. While the most economical application method would involve incorporating the fumigant treatment holes into the conventional predrilling process, it would also result in preservative treated fumigant holes. Consequently we have initiated studies to determine the influence of creosote and pentachlorophenol on fumigant movement into treated wood. Preliminary results indicate that creosote and P-9 penta base oil slow movement of MIT into wood but do not prevent the build up of fungitoxic concentrations in the wood. The new, pelletized MIT formulation has been evaluated in our laboratory assay for wood fumigants. The results indicate that pelletized MIT is as effective as pure MIT on an active ingredient basis. Since pelletized MIT has many similar application and safety advantages as encapsulated MIT, we intend to further evaluate pellets in poles in service. Cedar Sapwood Decay Control The effectiveness of seventeen chemicals (3 oil-borne, 14 water-borne) for controlling above-ground decay of cedar sapwood was evaluated using a modified soil block test and an Aspergillus bioassay. Pentachlorophenol (10%) in diesel oil, currently used for protecting cedar poles, was markedly superior to all other chemicals evaluated probably because of the increased penetrability of the oil, since penta in water at the same strength did not perform as well. Three other formulations, copper-8-quinolinolate (oil), pentachlorophenol (2% in water), and 3-iodo propynyl butyl carbamate (2% in water), exhibited some residual effectiveness; however, more time is necessary to determine if these chemicals will remain effective. An additional five chemicals will be evaluated this coming spring. iii The persistence of chloropicrin 5 years after treatment in western redcedar was also evaluated using open tube bioassays, closetube bioassays and gas chromatographic determinations. The open tube bioassay indicated that chioropicrin still effectively limited growth of the assay fungus, P. placenta. Similarly, closed tube bioassays indicated strong inhibition in the pole interior and lower inhibitions near the surface. Extraction/gas chromatographic procedures detected chloropicrin in all cores examined with the highest concentrations towards the pole interior. Chioropicrin concentration did not correlate with closed tube results, suggesting that these tests are measuring different fumigant properties. The results indicate that chloropicrin should be an effective treatment for preventing cedarbutt rot and may provide some protection to pole sapwood. Bolt Holes Control poles for the bolt hole protection study were again sampled and insufficient decay was found in these poles to warrant evaluation of the various decay prevention treatments. We will reevaluate the control poles this summer. Detecting decay and estimating residual strength in poles An infrared spectrophotometric method of analyzing warm water extracts of decayed and non-decay wood was evaluated with a number of brown and white rot fungi. Brown rot was highly correlated with absorption peaks produced at wavelength 17201cm. Work is now underway to identify this peak to determine if less involved detection methods might be employed. iv Fluorescent labeled lectins, which have high specificity for selected carbohydrates, were also evaluated as potential fungal indicators. Of the lectins tested, wheat germ agglutinin appears the most promising since it strongly reacted with chitin in the fungal cell wall, making decay hyphae visible at very early stages of decay. Evaluation of Douglas-fir beams air-seasoned for 1 or 2 years using Pilodyn pin penetration, longitudinal compression, radial compression, bending and culturing indicated that, while there is a well established fungal flora in the wood, this flora has not yet affected strength. These tests will be performed on the 3 year airseasoned beams this coming year. Of the strength tests employed, longitudinal compression appears promising for estimating pole bending strength and we intend to further evaluate this method. As a second phase of this evaluation, the effect of moisture content on Pilodyn pin penetration was examined. This information is necessary since pin penetration varies with moisture content and must be corrected to compare values from different poles. Pin penetration increased with increasing moisture content up to fiber saturation and stabilized above this point. The moisture content at 0.5 inches was highly correlated with pin penetration, and this depth might be a convenient standard measuring point. En a new phase of the project, preliminary acoustic testing was begun using small beams from poles at varying stages of decay. These beams were sonically evaluated and then loaded to failure in three point bending tests. Sonic evaluation was highly correlated with NOR; however, much more testing will be necessary before such an apparatus can be applied to posts or poles. V Initiation of decay in Douglas-fir poles prior to pressure treatment The ability of basidiomycetes isolated from air-seasoning poles to reduce wood strength was evaluated in rapid tests for toughness by impact bending and changes in the breaking radius of Douglas-fir test wafers. Although some fungi behaved differently in the two tests, the test correlations were relatively high (r2 = O.78S). Of 26 basidiomycetous species evaluated, Poria placenta, P. carbonica, P. xantha and Crustoderma dryinum most rapidly decayed Douglas-fir heartwood, but at least one isolate of most of the other species tested significantly reduced toughness. While the wood decaying ability of each fungus is important, the frequency of isolation also must be considered when determining the overall importance of a species. To determine the influence of wood temperature and moisture content on establishment of P. carbonica in Douglas-fir heartwood, a method was developed for direct observation of germinating spores on wood. In this test, chiamydospores and basidiospores failed to germinate or colonize wood at moisture content below fiber saturation suggesting that free water is necessary for infection. Chiamydospores germinated most readily and colonized wood at 22°C, while germination was significantly lower and the fungus failed to become established in wood at 5 or 35°C. Similar temperature responses were obtained with basidiospores although these spores failed to germinate at 5 and 35°C. Nevertheless, basidiospores may remain viable and retain the potential to establish colonies once conditions become more favorable. vi Exposure of sterilized pole sections at four Pacific Northwest air-seasoning sites for successive 3-month periods showed a significant increase in basidiomycete isolation frequency for the period Nov. '81-Jan.'82. Furthermore, the frequency increased from the northern to the southern most site. Detailed study of the site weather patterns strongly suggests that increased basidiomycetous infection can be related to number of days with measurable rain fall and temperatures conducive to fungal growth. During the other periods studied, temperature or precipitation conditions were unfavorable for infection and pole section moisture contents fell below fiber saturation. This in turn limited spore germination and fungal colonization of the wood. About 30 different basidiomycetous species have been identified from isolates cultured from sterilized pole sections exposed at the four sites. In general, the species were the same as those isolated form air-seasoning poles although there were some significant differences between the species obtained from the different sites. The frequency of P. placenta mono- and dikaryons was particularly high with monokaryons more abundant at three of the four locations. Individual species exhibited distinct colonization patterns from different pole zones. For example, P. placenta was isolated most frequently from heartwood exposed at the pole ends while Peniophora spp. and llaemotostereum sanguinolentum were recovered most frequently from the upper surfaces of the pole sections. vii Preventing infection of poles by decay fungi during air-seasoning Pole sections treated with ammonium bifluoride (NH4HF2) or gelatin encapsulated MIT and chioropicrin were extensively sampled after air seasoning to determine the influence of these chemicals on wood colonization by decay fungi. Preliminary results indicate that after 2 years NH4HF2 and the fumigants significantly reduced basidiomycetous colonization of sterile wood. Surface Decay Poles treated with Vapam 14 years ago were extensively cored, the cores were cultured and the resulting fungi were identified to evaluate the fungal flora of fumigant treated wood. A well developed fungal flora was identified that differed from that found in nonfumigant treated wood. These fungi will be further evaluated to determine their role in fumigant effectiveness. Close

• 8086. [Article] Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1985

  This fifth annual Cooperative Pole Research Program report outlines our progress in the six project objectives. Improved Fumigants Sampling of previously established field tests revealed that Vorlex and ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1985 Author: Oregon State University, Oregon State University. Dept. of Forest Products This fifth annual Cooperative Pole Research Program report outlines our progress in the six project objectives. Improved Fumigants Sampling of previously established field tests revealed that Vorlex and Chloropicrin continued to perform well after 15 years, while Vapam was slightly less effective. Solid methylisothiocyanate (MIT) also performed well in the field after 7 years. In additional tests, gelatin encapsulated MIT migrated through Douglas-fir heartwood with addition of moderate quantities of water to degrade the gelatin. However, in the presence of higher quantities of water or no additional water, MIT migration into the wood was slowed. In a previously established test, gelatin encapsulated MIT continues to inhibit reinfestation of poles 3 years after treatment. Pelletized MIT is a new formulation (65% active ingredient) that appears to have some promise. Preliminary tests indicate that up to 95% of the MIT is release in 24 hours, but a small quantity of MIT remains in the pellets after 63 days aeration and may pose a disposal hazard. The solid MIT formulations will permit aboveground applications, increasing the risk that MIT will come in contact with pole hardware. Preliminary tests indicate that MIT had little effect on corrosion of hot dipped, galvanized bolts attached to wood. This suggests that treatment in the crossarm zone with MIT or fumigants that produce MIT should not affect the integrity of attached hardware. i-i In addition to fumigant evaluations, we recently examined an earlier test of groundline treatments with Osmoplastic® and Hollowheart®. After 10 years, these treatments are performing reasonably well, with only a slight rise in the incidence of decay fungi in the past 4 years. We also reevaluated the effectiveness of kerfing for preventing decay and found that this process reduced the depth and width of checks, resulting in a decreased incidence of decay fungi. Kerfing appears to be a valuable method for preventing internal decay at the groundline. Cedar Sapwood Decay Control This past year, the second set of five chemicals applied to control sapwood decay were evaluated after 2 years of exposure. As in earlier evaluations using the Aspergillus bioassay, none of the chemicals approach pentachlorophenol in oil for ability to inhibit sporulation of Aspergillus niger; however, several samples from zones deep in the wood produced a slight zone of effect. This may indicate the presence of a reservoir for long-term protection against decay. Several of the chemicals including Fluor Chrome Arsenic Phenol and Ammoniacal Copper Arsenate (ACA) appear to bind to the wood and may be difficult to detect by the bioassay method. We expect to assess the effectiveness of these treatments using a soil block test. Investigations of the reliability of the Aspergillus bioassay under a variety of conditions indicated that quantity of spores, use of glass or plastic petri dishes, long-term cold storage, and the use of spray inoculum instead of flooding spores had little influence on the bioassay results with pentachiorophenol, Tributyl-tinoxide, or 3 iodo propynyl butylcarbamate; however, incubation temperature did influence assay results. The Aspergillus bioassay is a simple, effective means for estimating residual preservative levels. Bolt Holes Again this year, wood around the unprotected, control bolt holes in pole sections contained such low levels of decay fungi that evaluation of the treated poles will be delayed another year. In addition to the initial bolt hole treatments, we have begun a test to determine if gelatin encapsulated or pelletized MIT can prevent decay development in field-drilled bolt holes. The pole sections used in these tests had already begun to develop decay prior to treatment and will provide an ideal test material. Detecting Decay and Estimatin& Residual Strength of Poles Fluorescent labeled lectins used in our earlier studies detected decay fungi at low weight losses under laboratory conditions. We are currently evaluating this method for detecting fungi in increment cores removed from poles to reduce the need for culturing. Last year we identified a peak that was unique to infrared (IR) spectra of warm water extracts from decayed wood. This past year we attempted to identify the chemical responsible for this peak and found that carbonyl compounds, probably from oxidative lignin degradation, were responsible for the peak. Since brown rot fungi apparently do iv not completely metabolize lignin breakdown products, they accumulate in the decaying wood and can be readily detected by their IR spectra. Strength properties of beams cut front Douglas-fir pole sections, air-seasoned for 3 years significantly decreased although decay fungi could not be uniformly isolated from the beams. In addition, there were gradual declines in work to maximum load and modulus of elasticity, as well as increased Pilodyn pin penetration. These results suggest that some strength losses occurred during air-seasoning; however, the losses were not large and should not endanger pole users. We compared several test methods including the Pilodyn, radial compression tests, longitudinal compression tests, and the pick test for evaluating residual pole strength of the wood surface of Douglas-fir treated with combinations of funtigants or groundline wraps. The results indicate that only the pick test could accurately detect surface damage and illustrate the difficulty of detecting surface damage. This past year we evaluated several sections cut from ACA treated poles stored for a number of years to determine if they were worth salvaging. Static bending tests of beams cut from the ACA treated zone, the treated/untreated boundary, and the inner heartwood revealed ACA treated sapwood had lower MOR and longitudinal compression strength than the other zones. These results represent only a small sample, but they suggest that some strength loss occurs during ACA V treatments. More importantly, the results suggest that we could have reliably predicted beam MOR by testing small plugs removed from the poles. Small beams cut from decaying, pentachlorophenol treated Douglas-fir poles were acoustically tested for residual wood strength, then evaluated to failure in static bending. The acoustic test consisted of sending a pulsed sonic wave into the wood and recording this wave after it passed through the beam. As it moved, the wave was altered by the presence of any wood defects or decay, and these alterations create a "fingerprint" specific for that defect. Preliminary results indicated that signal analysis was highly 2 2 correlated with work to maximum load (r =.82) and MOR (r .88), suggesting that this approach to decay detection may prove more reliable than measuring of sound velocity. Initiation of Decay in Air-Seasoning Douglas-fir The results of the initial survey to determine the incidence of decay fungi in poles from widely scattered Pacific Northwest seasoning yards indicated that a variety of fungi were colonizing the wood. While most of these fungi do not pose a serious decay problem, two species, Poria carbonica and Poria placenta, became increasingly abundant with length of air-seasoning. These fungi are also the most conunon decayers of Douglas-fir poles in service. As expected, the number of fungi and the wood volume they occupied increased with seasoning time; however, this incidence varied considerably between yards, especially in poles air-seasoned for vi shorter time periods. In addition to the variation between sites, many of the decay fungi colonizing the wood appear to be monokaryons, indicating that spores landing on the wood are initiating the infestation. The distribution of fungi within the poles indicated that several of the more abundant decay fungi were present in the outer sapwood where they would be eliminated by conventional pressure treatment. The remaining fungi were most abundant in the heartwood but were more concentrated near the pole end. This suggests that exposed end grain was more readily invaded than lateral grain exposed in checks. In addition to identifying the fungi colonizing Douglas-fir, we examined the effects these fungi had on wood strength. Toughness tests indicated the presence of wide variation in decay capability of the isolates. Although there was no consistent pattern, most of the isolates did not cause substantial decay and, of those that did, only . carbonica and P. placenta were sufficiently abundant to have a large influence on wood strength. Due to the prevalence of P. carbonica and P. placenta in the inner heartwood, where they might not be eliminated in a short heating cycle, we evaluated the temperature tolerance of these two fungi in Douglas-fir heartwood blocks. These tests indicated that both fungi were eliminated by exposure to temperatures above 71°C for over 1 hour or 60°C for 2 hours. The results suggest that careful control of temperature during treatment should eliminate decay fungi and that wood treated at ambient temperatures should be heated to kill fungi that become established during air-seasoning. vii This past year was the third and final year of the decay development study. In this study, sterile pole sections have been exposed for 1, 2, or 3 years at widely scattered Pacific Northwest sites, then returned to the laboratory and extensively sampled. We are now in the process of identifying the fungi from the third year poles. In addition to examining poles prior to preservative treatment, we are also evaluating poles treated with waterborne chemicals (ACA or CCA) for the incidence of surface decay. This past year we examined twenty ACA-treated poles from a line installed in 1946. While a variety of fungi were cultured from the wood, none of the poles had evidence of substantial surface deterioration. A study was initiated on the fungal flora of fumigant treated wood because of the potential for fungi developing resistance to low levels of fumigant or the ability to actively degrade the chemical. Both of these developments could shorten fumigant retreatment cycles and increase maintenance costs. We have evaluated poles treated 7 and 15 years ago with fumigants and find markedly reduced fungal flora. Tests are continuing on the fungi isolated, and we hope to assess the effects of these isolates on long-term fumigant effectiveness. Title: Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1985 Author: Oregon State University, Oregon State University. Dept. of Forest Products This fifth annual Cooperative Pole Research Program report outlines our progress in the six project objectives. Improved Fumigants Sampling of previously established field tests revealed that Vorlex and Chloropicrin continued to perform well after 15 years, while Vapam was slightly less effective. Solid methylisothiocyanate (MIT) also performed well in the field after 7 years. In additional tests, gelatin encapsulated MIT migrated through Douglas-fir heartwood with addition of moderate quantities of water to degrade the gelatin. However, in the presence of higher quantities of water or no additional water, MIT migration into the wood was slowed. In a previously established test, gelatin encapsulated MIT continues to inhibit reinfestation of poles 3 years after treatment. Pelletized MIT is a new formulation (65% active ingredient) that appears to have some promise. Preliminary tests indicate that up to 95% of the MIT is release in 24 hours, but a small quantity of MIT remains in the pellets after 63 days aeration and may pose a disposal hazard. The solid MIT formulations will permit aboveground applications, increasing the risk that MIT will come in contact with pole hardware. Preliminary tests indicate that MIT had little effect on corrosion of hot dipped, galvanized bolts attached to wood. This suggests that treatment in the crossarm zone with MIT or fumigants that produce MIT should not affect the integrity of attached hardware. i-i In addition to fumigant evaluations, we recently examined an earlier test of groundline treatments with Osmoplastic® and Hollowheart®. After 10 years, these treatments are performing reasonably well, with only a slight rise in the incidence of decay fungi in the past 4 years. We also reevaluated the effectiveness of kerfing for preventing decay and found that this process reduced the depth and width of checks, resulting in a decreased incidence of decay fungi. Kerfing appears to be a valuable method for preventing internal decay at the groundline. Cedar Sapwood Decay Control This past year, the second set of five chemicals applied to control sapwood decay were evaluated after 2 years of exposure. As in earlier evaluations using the Aspergillus bioassay, none of the chemicals approach pentachlorophenol in oil for ability to inhibit sporulation of Aspergillus niger; however, several samples from zones deep in the wood produced a slight zone of effect. This may indicate the presence of a reservoir for long-term protection against decay. Several of the chemicals including Fluor Chrome Arsenic Phenol and Ammoniacal Copper Arsenate (ACA) appear to bind to the wood and may be difficult to detect by the bioassay method. We expect to assess the effectiveness of these treatments using a soil block test. Investigations of the reliability of the Aspergillus bioassay under a variety of conditions indicated that quantity of spores, use of glass or plastic petri dishes, long-term cold storage, and the use of spray inoculum instead of flooding spores had little influence on the bioassay results with pentachiorophenol, Tributyl-tinoxide, or 3 iodo propynyl butylcarbamate; however, incubation temperature did influence assay results. The Aspergillus bioassay is a simple, effective means for estimating residual preservative levels. Bolt Holes Again this year, wood around the unprotected, control bolt holes in pole sections contained such low levels of decay fungi that evaluation of the treated poles will be delayed another year. In addition to the initial bolt hole treatments, we have begun a test to determine if gelatin encapsulated or pelletized MIT can prevent decay development in field-drilled bolt holes. The pole sections used in these tests had already begun to develop decay prior to treatment and will provide an ideal test material. Detecting Decay and Estimatin& Residual Strength of Poles Fluorescent labeled lectins used in our earlier studies detected decay fungi at low weight losses under laboratory conditions. We are currently evaluating this method for detecting fungi in increment cores removed from poles to reduce the need for culturing. Last year we identified a peak that was unique to infrared (IR) spectra of warm water extracts from decayed wood. This past year we attempted to identify the chemical responsible for this peak and found that carbonyl compounds, probably from oxidative lignin degradation, were responsible for the peak. Since brown rot fungi apparently do iv not completely metabolize lignin breakdown products, they accumulate in the decaying wood and can be readily detected by their IR spectra. Strength properties of beams cut front Douglas-fir pole sections, air-seasoned for 3 years significantly decreased although decay fungi could not be uniformly isolated from the beams. In addition, there were gradual declines in work to maximum load and modulus of elasticity, as well as increased Pilodyn pin penetration. These results suggest that some strength losses occurred during air-seasoning; however, the losses were not large and should not endanger pole users. We compared several test methods including the Pilodyn, radial compression tests, longitudinal compression tests, and the pick test for evaluating residual pole strength of the wood surface of Douglas-fir treated with combinations of funtigants or groundline wraps. The results indicate that only the pick test could accurately detect surface damage and illustrate the difficulty of detecting surface damage. This past year we evaluated several sections cut from ACA treated poles stored for a number of years to determine if they were worth salvaging. Static bending tests of beams cut from the ACA treated zone, the treated/untreated boundary, and the inner heartwood revealed ACA treated sapwood had lower MOR and longitudinal compression strength than the other zones. These results represent only a small sample, but they suggest that some strength loss occurs during ACA V treatments. More importantly, the results suggest that we could have reliably predicted beam MOR by testing small plugs removed from the poles. Small beams cut from decaying, pentachlorophenol treated Douglas-fir poles were acoustically tested for residual wood strength, then evaluated to failure in static bending. The acoustic test consisted of sending a pulsed sonic wave into the wood and recording this wave after it passed through the beam. As it moved, the wave was altered by the presence of any wood defects or decay, and these alterations create a "fingerprint" specific for that defect. Preliminary results indicated that signal analysis was highly 2 2 correlated with work to maximum load (r =.82) and MOR (r .88), suggesting that this approach to decay detection may prove more reliable than measuring of sound velocity. Initiation of Decay in Air-Seasoning Douglas-fir The results of the initial survey to determine the incidence of decay fungi in poles from widely scattered Pacific Northwest seasoning yards indicated that a variety of fungi were colonizing the wood. While most of these fungi do not pose a serious decay problem, two species, Poria carbonica and Poria placenta, became increasingly abundant with length of air-seasoning. These fungi are also the most conunon decayers of Douglas-fir poles in service. As expected, the number of fungi and the wood volume they occupied increased with seasoning time; however, this incidence varied considerably between yards, especially in poles air-seasoned for vi shorter time periods. In addition to the variation between sites, many of the decay fungi colonizing the wood appear to be monokaryons, indicating that spores landing on the wood are initiating the infestation. The distribution of fungi within the poles indicated that several of the more abundant decay fungi were present in the outer sapwood where they would be eliminated by conventional pressure treatment. The remaining fungi were most abundant in the heartwood but were more concentrated near the pole end. This suggests that exposed end grain was more readily invaded than lateral grain exposed in checks. In addition to identifying the fungi colonizing Douglas-fir, we examined the effects these fungi had on wood strength. Toughness tests indicated the presence of wide variation in decay capability of the isolates. Although there was no consistent pattern, most of the isolates did not cause substantial decay and, of those that did, only . carbonica and P. placenta were sufficiently abundant to have a large influence on wood strength. Due to the prevalence of P. carbonica and P. placenta in the inner heartwood, where they might not be eliminated in a short heating cycle, we evaluated the temperature tolerance of these two fungi in Douglas-fir heartwood blocks. These tests indicated that both fungi were eliminated by exposure to temperatures above 71°C for over 1 hour or 60°C for 2 hours. The results suggest that careful control of temperature during treatment should eliminate decay fungi and that wood treated at ambient temperatures should be heated to kill fungi that become established during air-seasoning. vii This past year was the third and final year of the decay development study. In this study, sterile pole sections have been exposed for 1, 2, or 3 years at widely scattered Pacific Northwest sites, then returned to the laboratory and extensively sampled. We are now in the process of identifying the fungi from the third year poles. In addition to examining poles prior to preservative treatment, we are also evaluating poles treated with waterborne chemicals (ACA or CCA) for the incidence of surface decay. This past year we examined twenty ACA-treated poles from a line installed in 1946. While a variety of fungi were cultured from the wood, none of the poles had evidence of substantial surface deterioration. A study was initiated on the fungal flora of fumigant treated wood because of the potential for fungi developing resistance to low levels of fumigant or the ability to actively degrade the chemical. Both of these developments could shorten fumigant retreatment cycles and increase maintenance costs. We have evaluated poles treated 7 and 15 years ago with fumigants and find markedly reduced fungal flora. Tests are continuing on the fungi isolated, and we hope to assess the effects of these isolates on long-term fumigant effectiveness. Close

• 8087. [Article] The influence of climate change and restoration on stream temperature

  Water temperature is an essential property of a stream. Temperature regulates physical and biochemical processes in aquatic habitats. Various factors related to climatic conditions, landscape characteristics, ...

  Citation × Citation Citation Abstract Copy Title: The influence of climate change and restoration on stream temperature Author: Diabat, Mousa Water temperature is an essential property of a stream. Temperature regulates physical and biochemical processes in aquatic habitats. Various factors related to climatic conditions, landscape characteristics, and channel structure directly influence stream temperature. Numerous studies indicate that increased average air temperature during the past century has led to stream warming across the world. The trend of stream warming was also present in spring-fed watersheds, where summer flow has decreased. In addition, anthropogenic practices that alter the natural landscape and channel structure, such as forest management, agriculture, and mining contributed to stream warming. For example, deforested and unshaded stream reaches or dredged channels were warmer than shaded reaches and meandering streams. Stream temperatures in North American lotic habitats are of a specific concern due to their significant economic, cultural, and ecological value. With climate projections indicating that air temperature will only continue to rise throughout the 21st century, cold- or cool-water organisms, especially fishes, will be affected. Therefore, there is a strong need to better understand the impacts of changing climate, riparian landscape, and channel structure on a stream's heat budget. This may assist in restoring the historic thermal regime in impacted sites and mitigating the impacts of future climate change. This study looks into the relative influences of the different factors on a stream's heat budget with three manuscripts: one on stream temperature response to diel timing of air warming, one on stream temperature response to changes in air temperature, flow, and riparian vegetation, and one on stream temperature response to air warming and channel reconstruction. I used the software Heat Source version 8.05 to simulate stream temperature for all three analyses along the Middle Fork John Day River, Oregon USA. Two of the manuscripts were applied to an upper 37 km section of the Middle Fork John Day River (presented in chapter 2 and 3), where the third manuscript was applied to a 1.5-km section. The sensitivity analysis of stream temperature response to diel timing of air warming (Chapter 2: Diel Timing of Warmer Air under Climate Change Affects Magnitude, Timing, and Duration of Stream Temperature Change) was based on scenarios representing uniform air warming over the diel period, daytime warming, and nighttime warming. Uniform warming of air temperature is a simple representation of increases in the average daily or monthly temperatures generated by the 'delta method'. The delta method relies on adding a constant value to the air temperature time-series data. This constant value is the difference (delta) between base case average air temperatures and the projected one. Scenarios of daytime or nighttime warming represent conditions under which most of the warming of the air occurs during the daytime or the nighttime, respectively. I simulated the stream temperature response to warmer air conditions of +2 °C and +4 °C in daily average for all three cases of air warming conditions. The three cases of different diel distributions of air warming generated 7-day average daily maximum stream temperature (7DADM) increases of approximately +1.8 °C ± 0.1 °C at the downstream end of the study section relative to the base case. In most parts of the reach, the three distributions of air warming generated different ranges of stream temperatures, different 7DADM values, different durations of stream temperature changes, and different average daily temperatures. Changes of stream temperature were out of phase with imposed changes of air temperature. Therefore, nighttime warming of air temperatures would cause the greatest increase in maximum daily stream temperature, which typically occurs during the daytime. The sensitivity analysis of the relative influences of changes in air temperature, stream flow, and riparian vegetation on stream temperature (Chapter 3: Assessing Stream Temperature Response to Cumulative Influence of Changing Air Temperature, Flow, and Riparian Vegetation). This study summarized stream temperature simulation in 36 scenarios representing possible manifestations of 21st century climate conditions and land management strategies. In addition to existing conditions (base case) of flow, air temperature, and riparian vegetation, scenarios consisted of: two air temperature increases of 2 °C and 4 °C, two stream flow variations of +30% and -30%, three spatially uniform riparian vegetation conditions that create averages of effective shade 7%, 34%, and 79%, in addition to 14% for base case conditions. Results suggest that variation in riparian vegetation was the dominant factor influencing stream temperature because it regulates incoming shortwave radiation, the largest heat input to the stream, while variation in stream flow has a negligible influence. Results indicated that increasing the effective shade along the study section, particularly in the currently unshaded sections, could mitigate the influence of increasing air temperature, and would reduce stream temperature maxima below current values even under future climate conditions of warmer air. With the small influence it had, increasing stream flow reduced the 7DADM under low shade conditions. However, increasing stream flow showed counterintuitive results as it contributed to increasing stream temperature maxima when the stream was heavily shaded. The applied study examined the stream temperature response to restoration practices and their potential to mitigate the influence of warmer air conditions (Chapter 4: Estimating Stream Temperature Response to Restoring Channel and Riparian Vegetation and the Potential to Mitigate Warmer Air Conditions). This study focused on a 1.5 km section along the upper part of the Middle Fork John Day River that was modified due to past anthropogenic activities of mining for gold and timber harvest. Currently, the riparian vegetation of the study site is mostly shrubs and stands of short trees. Restoration designs call for the restoration of both the channel structure and replanting the riparian vegetation. Simulation results showed that the 7DADM was higher in the restored channel than the existing channel with both conditions of low and high effective shade conditions. However, a combined restoration practice of channel reconstruction and medium effective shade conditions reduced stream temperature maxima more than restoring riparian vegetation alone. In addition, results showed that restoring riparian vegetation was sufficient to mitigate the influence of warmer air on stream temperature, while restoring the channel alone is not. Heat budget analysis showed that heat accumulation during the daytime increased in the restored channel, which was longer, narrower, and deeper than the existing channel. It is important to emphasize that stream temperature is one of many goals that restoration activities aim to improve. Furthermore, differences in 7DADM among the different scenarios of restoration are negligible. Such small differences could hardly be measure. While this study examined a short section of 1.5 km, longer stream sections may increase the differences in 7DADM. Primary conclusions of this study are: 1) daily maxima of stream temperature will increase in response to increased air temperature regardless of the distribution of air warming during the diel cycle; 2) nighttime air warming caused a greater increase in stream temperature maximum than daytime warming; 3) riparian vegetation was the dominant factor on stream's heat budget, more than air temperature or stream flow; 4) restoring riparian vegetation mitigated the influence of warmer air; 5) restoring channel structure alone was not sufficient to lower temperature maxima; and 6) restoration project was most successful in improving degraded stream temperature when combined with channel reconstruction and improved riparian shade. Title: The influence of climate change and restoration on stream temperature Author: Diabat, Mousa Water temperature is an essential property of a stream. Temperature regulates physical and biochemical processes in aquatic habitats. Various factors related to climatic conditions, landscape characteristics, and channel structure directly influence stream temperature. Numerous studies indicate that increased average air temperature during the past century has led to stream warming across the world. The trend of stream warming was also present in spring-fed watersheds, where summer flow has decreased. In addition, anthropogenic practices that alter the natural landscape and channel structure, such as forest management, agriculture, and mining contributed to stream warming. For example, deforested and unshaded stream reaches or dredged channels were warmer than shaded reaches and meandering streams. Stream temperatures in North American lotic habitats are of a specific concern due to their significant economic, cultural, and ecological value. With climate projections indicating that air temperature will only continue to rise throughout the 21st century, cold- or cool-water organisms, especially fishes, will be affected. Therefore, there is a strong need to better understand the impacts of changing climate, riparian landscape, and channel structure on a stream's heat budget. This may assist in restoring the historic thermal regime in impacted sites and mitigating the impacts of future climate change. This study looks into the relative influences of the different factors on a stream's heat budget with three manuscripts: one on stream temperature response to diel timing of air warming, one on stream temperature response to changes in air temperature, flow, and riparian vegetation, and one on stream temperature response to air warming and channel reconstruction. I used the software Heat Source version 8.05 to simulate stream temperature for all three analyses along the Middle Fork John Day River, Oregon USA. Two of the manuscripts were applied to an upper 37 km section of the Middle Fork John Day River (presented in chapter 2 and 3), where the third manuscript was applied to a 1.5-km section. The sensitivity analysis of stream temperature response to diel timing of air warming (Chapter 2: Diel Timing of Warmer Air under Climate Change Affects Magnitude, Timing, and Duration of Stream Temperature Change) was based on scenarios representing uniform air warming over the diel period, daytime warming, and nighttime warming. Uniform warming of air temperature is a simple representation of increases in the average daily or monthly temperatures generated by the 'delta method'. The delta method relies on adding a constant value to the air temperature time-series data. This constant value is the difference (delta) between base case average air temperatures and the projected one. Scenarios of daytime or nighttime warming represent conditions under which most of the warming of the air occurs during the daytime or the nighttime, respectively. I simulated the stream temperature response to warmer air conditions of +2 °C and +4 °C in daily average for all three cases of air warming conditions. The three cases of different diel distributions of air warming generated 7-day average daily maximum stream temperature (7DADM) increases of approximately +1.8 °C ± 0.1 °C at the downstream end of the study section relative to the base case. In most parts of the reach, the three distributions of air warming generated different ranges of stream temperatures, different 7DADM values, different durations of stream temperature changes, and different average daily temperatures. Changes of stream temperature were out of phase with imposed changes of air temperature. Therefore, nighttime warming of air temperatures would cause the greatest increase in maximum daily stream temperature, which typically occurs during the daytime. The sensitivity analysis of the relative influences of changes in air temperature, stream flow, and riparian vegetation on stream temperature (Chapter 3: Assessing Stream Temperature Response to Cumulative Influence of Changing Air Temperature, Flow, and Riparian Vegetation). This study summarized stream temperature simulation in 36 scenarios representing possible manifestations of 21st century climate conditions and land management strategies. In addition to existing conditions (base case) of flow, air temperature, and riparian vegetation, scenarios consisted of: two air temperature increases of 2 °C and 4 °C, two stream flow variations of +30% and -30%, three spatially uniform riparian vegetation conditions that create averages of effective shade 7%, 34%, and 79%, in addition to 14% for base case conditions. Results suggest that variation in riparian vegetation was the dominant factor influencing stream temperature because it regulates incoming shortwave radiation, the largest heat input to the stream, while variation in stream flow has a negligible influence. Results indicated that increasing the effective shade along the study section, particularly in the currently unshaded sections, could mitigate the influence of increasing air temperature, and would reduce stream temperature maxima below current values even under future climate conditions of warmer air. With the small influence it had, increasing stream flow reduced the 7DADM under low shade conditions. However, increasing stream flow showed counterintuitive results as it contributed to increasing stream temperature maxima when the stream was heavily shaded. The applied study examined the stream temperature response to restoration practices and their potential to mitigate the influence of warmer air conditions (Chapter 4: Estimating Stream Temperature Response to Restoring Channel and Riparian Vegetation and the Potential to Mitigate Warmer Air Conditions). This study focused on a 1.5 km section along the upper part of the Middle Fork John Day River that was modified due to past anthropogenic activities of mining for gold and timber harvest. Currently, the riparian vegetation of the study site is mostly shrubs and stands of short trees. Restoration designs call for the restoration of both the channel structure and replanting the riparian vegetation. Simulation results showed that the 7DADM was higher in the restored channel than the existing channel with both conditions of low and high effective shade conditions. However, a combined restoration practice of channel reconstruction and medium effective shade conditions reduced stream temperature maxima more than restoring riparian vegetation alone. In addition, results showed that restoring riparian vegetation was sufficient to mitigate the influence of warmer air on stream temperature, while restoring the channel alone is not. Heat budget analysis showed that heat accumulation during the daytime increased in the restored channel, which was longer, narrower, and deeper than the existing channel. It is important to emphasize that stream temperature is one of many goals that restoration activities aim to improve. Furthermore, differences in 7DADM among the different scenarios of restoration are negligible. Such small differences could hardly be measure. While this study examined a short section of 1.5 km, longer stream sections may increase the differences in 7DADM. Primary conclusions of this study are: 1) daily maxima of stream temperature will increase in response to increased air temperature regardless of the distribution of air warming during the diel cycle; 2) nighttime air warming caused a greater increase in stream temperature maximum than daytime warming; 3) riparian vegetation was the dominant factor on stream's heat budget, more than air temperature or stream flow; 4) restoring riparian vegetation mitigated the influence of warmer air; 5) restoring channel structure alone was not sufficient to lower temperature maxima; and 6) restoration project was most successful in improving degraded stream temperature when combined with channel reconstruction and improved riparian shade. Close