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• 1781. [Article] The Factors Affecting the Diets of Groundfish in the Gulf of Alaska : Ecological and Modeling Considerations

  Marine systems undergo changes in community composition over time as a result of a variety of environmental and anthropogenic factors. Understanding these community changes and the factors that drive them ...

  Citation × Citation Citation Abstract Copy Title: The Factors Affecting the Diets of Groundfish in the Gulf of Alaska : Ecological and Modeling Considerations Author: Thompson, Kevin A. Marine systems undergo changes in community composition over time as a result of a variety of environmental and anthropogenic factors. Understanding these community changes and the factors that drive them is critical for ecosystem management of marine resources. The Gulf of Alaska (GOA) is a large marine ecosystem that includes a variety of species that support large scale fisheries. This is also a system in which large scale community shifts, or regime shifts, have occurred due to the Pacific Decadal Oscillation (PDO) and fishing pressure. Given the economic and conservation importance of this marine system, the GOA has been modeled using a variety of multispecies, or ecosystem, models. While this work has been critical in understanding the ecosystem dynamics of the GOA and helped generate management recommendations for commercial species, these models often make assumptions regarding trophic-dynamics, particularly that predator-prey relationships follow a standard functional response and do not change through time in response to environmental variables. However, empirical evidence suggests that a predator's diet can be influenced by a variety of factors, abiotic and biotic, at large and small spatial scales. Our overall objective was to investigate the potential impact environmental variables may have in structuring this ecosystem by using statistical analyses of diets and an ecosystem modeling framework. We focused on three commercially and ecologically important groundfish predators: Pacific Cod (Gadus macrocephalus), Pacific Halibut (Hippoglossus stenolepis), and Sablefish (Anoplopoma fimbria). We also focused on a key prey species, Walleye Pollock (Gadus chalcogrammus), and used environmental data collected during trawl surveys and PDO data generated for the entire North Pacific region. The first study completed was focused solely on the consumption of Walleye Pollock, a critical fishery species and ecosystem link. We used data from trawl surveys to determine the potential influence of local environmental variables on the predation rate of Walleye Pollock in the system by these groundfish. Using an information-theoretic approach, we found that predator length was positively related to Walleye Pollock presence and proportion of total diet weight in all predators. Increased temperatures positively affected consumption of Walleye Pollock by Pacific Halibut, but not the other predators. We found evidence for a number of inter-predator effects of co-occurring predators, both positive (facultative) and negative (competitive). Observed prey density was not statistically significant with respect to consumption for these predators, suggesting that trawls sample the environment differently than Walleye Pollock predators or species interactions are more complex than those used in previous multispecies models. In our second study, we considered the entire diet of these predators, rather than one key prey. Furthermore, because PDO had been described as leading to community changes in the system previously, we hypothesized that it could also be driving shifts in diets in the three groundfish predators we studied. We used a multivariate statistical approach to compare the diets of these predators by PDO state (warm or cold years) and also included local environmental covariates. Overall, we found that diets observed in PDO cold years were significantly different than diets in fish in warm years. In general, predators were found to be consuming more Walleye Pollock and euphausiids in warm years, and more benthic invertebrates and other forage fish in cold years. Local environmental covariates contributed to the diets observed in these predators, however no general pattern was observed. Our results also show the benefit of using diet data from large scale monitoring efforts as indicators of community shifts in a large marine ecosystem through time. Ultimately, we used our statistical analyses regarding diet and PDO state to drive a modeling exercise using alternate representations of the diets of the predators in the GOA. We investigated the potential impact of shifting diets in groundfish in an ecosystem-modeling framework, using Ecopath trophic-mass balance models. We changed the diets of key groundfish predators in the model based on our previous results for three alternative model parametrizations; 1) average conditions over the time period, 2) cold PDO state, and 3) warm PDO state. We noted a number of differences in model estimated ecosystem indices. Biomass accumulation estimates indicated that some ecologically and commercially important species groups would be expected to greatly diverge in population size if models were based on data from warm vs. cold PDO years compared to the averaged climatic state. In general, predator overlap was at its lowest in the cold year model, as predators had more diverse diets and therefore predation was more diffuse in the system in general. These results indicate the potential importance of environmental context when collecting diet data to be used in ecosystem models designed to provide fishery management recommendations. As ecosystem models are used more commonly, taking the time to investigate the factors that structure diets and how predation changes due to environment can yield more representative, and potentially more accurate biomass projections and recommendations for the GOA and likely many other managed marine ecosystems. Title: The Factors Affecting the Diets of Groundfish in the Gulf of Alaska : Ecological and Modeling Considerations Author: Thompson, Kevin A. Marine systems undergo changes in community composition over time as a result of a variety of environmental and anthropogenic factors. Understanding these community changes and the factors that drive them is critical for ecosystem management of marine resources. The Gulf of Alaska (GOA) is a large marine ecosystem that includes a variety of species that support large scale fisheries. This is also a system in which large scale community shifts, or regime shifts, have occurred due to the Pacific Decadal Oscillation (PDO) and fishing pressure. Given the economic and conservation importance of this marine system, the GOA has been modeled using a variety of multispecies, or ecosystem, models. While this work has been critical in understanding the ecosystem dynamics of the GOA and helped generate management recommendations for commercial species, these models often make assumptions regarding trophic-dynamics, particularly that predator-prey relationships follow a standard functional response and do not change through time in response to environmental variables. However, empirical evidence suggests that a predator's diet can be influenced by a variety of factors, abiotic and biotic, at large and small spatial scales. Our overall objective was to investigate the potential impact environmental variables may have in structuring this ecosystem by using statistical analyses of diets and an ecosystem modeling framework. We focused on three commercially and ecologically important groundfish predators: Pacific Cod (Gadus macrocephalus), Pacific Halibut (Hippoglossus stenolepis), and Sablefish (Anoplopoma fimbria). We also focused on a key prey species, Walleye Pollock (Gadus chalcogrammus), and used environmental data collected during trawl surveys and PDO data generated for the entire North Pacific region. The first study completed was focused solely on the consumption of Walleye Pollock, a critical fishery species and ecosystem link. We used data from trawl surveys to determine the potential influence of local environmental variables on the predation rate of Walleye Pollock in the system by these groundfish. Using an information-theoretic approach, we found that predator length was positively related to Walleye Pollock presence and proportion of total diet weight in all predators. Increased temperatures positively affected consumption of Walleye Pollock by Pacific Halibut, but not the other predators. We found evidence for a number of inter-predator effects of co-occurring predators, both positive (facultative) and negative (competitive). Observed prey density was not statistically significant with respect to consumption for these predators, suggesting that trawls sample the environment differently than Walleye Pollock predators or species interactions are more complex than those used in previous multispecies models. In our second study, we considered the entire diet of these predators, rather than one key prey. Furthermore, because PDO had been described as leading to community changes in the system previously, we hypothesized that it could also be driving shifts in diets in the three groundfish predators we studied. We used a multivariate statistical approach to compare the diets of these predators by PDO state (warm or cold years) and also included local environmental covariates. Overall, we found that diets observed in PDO cold years were significantly different than diets in fish in warm years. In general, predators were found to be consuming more Walleye Pollock and euphausiids in warm years, and more benthic invertebrates and other forage fish in cold years. Local environmental covariates contributed to the diets observed in these predators, however no general pattern was observed. Our results also show the benefit of using diet data from large scale monitoring efforts as indicators of community shifts in a large marine ecosystem through time. Ultimately, we used our statistical analyses regarding diet and PDO state to drive a modeling exercise using alternate representations of the diets of the predators in the GOA. We investigated the potential impact of shifting diets in groundfish in an ecosystem-modeling framework, using Ecopath trophic-mass balance models. We changed the diets of key groundfish predators in the model based on our previous results for three alternative model parametrizations; 1) average conditions over the time period, 2) cold PDO state, and 3) warm PDO state. We noted a number of differences in model estimated ecosystem indices. Biomass accumulation estimates indicated that some ecologically and commercially important species groups would be expected to greatly diverge in population size if models were based on data from warm vs. cold PDO years compared to the averaged climatic state. In general, predator overlap was at its lowest in the cold year model, as predators had more diverse diets and therefore predation was more diffuse in the system in general. These results indicate the potential importance of environmental context when collecting diet data to be used in ecosystem models designed to provide fishery management recommendations. As ecosystem models are used more commonly, taking the time to investigate the factors that structure diets and how predation changes due to environment can yield more representative, and potentially more accurate biomass projections and recommendations for the GOA and likely many other managed marine ecosystems. Close

• 1782. [Article] Lake level regulation, shoreline erosion and shore protection : Flathead Lake, Montana

  Concern regarding increased coastal erosion has heightened amid growing acceptance of global warming and associated sea-level rise. This study examines shoreline erosion in Flathead Lake, Montana due to ...

  Citation × Citation Citation Abstract Copy Title: Lake level regulation, shoreline erosion and shore protection : Flathead Lake, Montana Author: Lorang, Mark Concern regarding increased coastal erosion has heightened amid growing acceptance of global warming and associated sea-level rise. This study examines shoreline erosion in Flathead Lake, Montana due to five decades of artificially elevated lake levels. It provides a model to investigate coastal erosion associated with sea-level rise. The natural water level fluctuation in Flathead Lake is regulated witha dam, which has elevated the entire annual fluctuation approximately 0.7 m on average. The annual rise in lake level is held for an extended duration at a regulated "full pool" level which is approximately 3 m above its natural base elevation, and the total transgression time for a complete cycle of lake level change has been increased from 100 days to over 300 days. Nearshore environments in Flathead Lake, are described as dissipative or reflective on the basis of a surf similarity parameter, grain size, morphology, number of breaking waves and angle of wave incidence. The relative resistance to foreshore and backshore erosion caused by anthropogenic lake level regulation is compared between the two nearshore configurations. Reflective systems are characterized by dynamic gravel beach faces and steep inshore shelves armored by wave-washed cobble. In contrast dissipative systems are characterized by sand-sized substratum, broad flat inshore shelves, and the presence of multiple linear bars approximately 350 m offshore. Five decades of regulated lake levels have resulted in extensive shoreline erosion (970 ha on the north shore of the lake) and a general reshaping of both types of nearshore environments, although dissipative shorelines have eroded faster. The presence of docks and other man-made structures on reflective beaches have accelerated erosion by intercepting longshore gravel transport. Shoreline erosion has ceased on the west side of the north shore as the varial zone, (that area between the maximum and minimum regulated lake levels), has reached an equilibrium slope. In contrast erosion and shoreline retreat continues on the east side, although the rate has slowed over the years in response to the development of a near equilibrium varial zone profile similar to that of the west side. However shoreline retreat is quite variable even along short stretches of shoreline. Variability in shoreline retreat results from three erosive processes, undercutting, endstripping and overwash. Undercutting and endstripping occur when waves scour an exposed bank, while overwash results when water is forced over the top of the shoreline bank or berm. Therefore shoreline elevation and morphology determine the type of erosion process, and the rate of shoreline retreat. Localized accretion also occurred due to sediment entrapment by drift logs bordering the shoreline. Drift logs naturally protect the shoreline from direct wave attack and once buried, provide new recruitment area for riparian vegetation. Alteration of lake level fluctuation has resulted in a transfer of annual wave energy from base elevations corresponding to the pre-dam nearshore shelf, to those corresponding with the limnetic foreshore environment, thereby inducing lake-wide erosion. The most extensive retreat has occurred along the low-lying dissipative north shore of the lake. Measured shoreline retreat along the north shore is compared to the retreat predicted by the Bruun Rule. The Bruun Rule under-predicted the actual measured shoreline retreat by as much as an order of magnitude. The redistribution of annual wave energy due to regulated lake level fluctuation is the main factor contributing to erosion, a factor that is not accounted for with the Bruun Rule. Therefore the redistribution of annual incident wave energy is examined in terms of an increased transgression time, a reduced range in lake level fluctuation, and an elevated lake level. Both transgression time and range in water level fluctuation affect the distribution of incident wave energy and were found to be more important to shoreline erosion than an elevated water level. An alternative regulation scheme incorporating both concerns for hydropower production and lake regulation is proposed and examined in terms of reducing erosion. Altering the transgression time of lake level fluctuation by changing the timing and increasing the rate of lake level drawdown, results in a significant reduction in the amount of annual wave energy that reaches the eroding full pool shoreline, thereby reducing the potential for shoreline erosion lake-wide. A lowered regulated full pooi lake level would decrease the intensity of overwash further reducing shoreline retreat related to that process of erosion. Natural gravel beaches can provide the backshore of coastal environments with a protective buffer from wave erosion. A case study is presented of the conceptual design and utility of an artificial perched gravel beach used to stabilize an eroding backshore on the reflective east shore of the lake. Boulders and cobbles were used as a stable platform to perch beach gravels above the previously eroding profile. A longshore exchange of gravel within the beach compartment was incorporated into the conceptual design. The structure has performed successfully during the three year monitoring period as exemplified by the lack of backshore erosion and the maintenance of the perched profile. Title: Lake level regulation, shoreline erosion and shore protection : Flathead Lake, Montana Author: Lorang, Mark Concern regarding increased coastal erosion has heightened amid growing acceptance of global warming and associated sea-level rise. This study examines shoreline erosion in Flathead Lake, Montana due to five decades of artificially elevated lake levels. It provides a model to investigate coastal erosion associated with sea-level rise. The natural water level fluctuation in Flathead Lake is regulated witha dam, which has elevated the entire annual fluctuation approximately 0.7 m on average. The annual rise in lake level is held for an extended duration at a regulated "full pool" level which is approximately 3 m above its natural base elevation, and the total transgression time for a complete cycle of lake level change has been increased from 100 days to over 300 days. Nearshore environments in Flathead Lake, are described as dissipative or reflective on the basis of a surf similarity parameter, grain size, morphology, number of breaking waves and angle of wave incidence. The relative resistance to foreshore and backshore erosion caused by anthropogenic lake level regulation is compared between the two nearshore configurations. Reflective systems are characterized by dynamic gravel beach faces and steep inshore shelves armored by wave-washed cobble. In contrast dissipative systems are characterized by sand-sized substratum, broad flat inshore shelves, and the presence of multiple linear bars approximately 350 m offshore. Five decades of regulated lake levels have resulted in extensive shoreline erosion (970 ha on the north shore of the lake) and a general reshaping of both types of nearshore environments, although dissipative shorelines have eroded faster. The presence of docks and other man-made structures on reflective beaches have accelerated erosion by intercepting longshore gravel transport. Shoreline erosion has ceased on the west side of the north shore as the varial zone, (that area between the maximum and minimum regulated lake levels), has reached an equilibrium slope. In contrast erosion and shoreline retreat continues on the east side, although the rate has slowed over the years in response to the development of a near equilibrium varial zone profile similar to that of the west side. However shoreline retreat is quite variable even along short stretches of shoreline. Variability in shoreline retreat results from three erosive processes, undercutting, endstripping and overwash. Undercutting and endstripping occur when waves scour an exposed bank, while overwash results when water is forced over the top of the shoreline bank or berm. Therefore shoreline elevation and morphology determine the type of erosion process, and the rate of shoreline retreat. Localized accretion also occurred due to sediment entrapment by drift logs bordering the shoreline. Drift logs naturally protect the shoreline from direct wave attack and once buried, provide new recruitment area for riparian vegetation. Alteration of lake level fluctuation has resulted in a transfer of annual wave energy from base elevations corresponding to the pre-dam nearshore shelf, to those corresponding with the limnetic foreshore environment, thereby inducing lake-wide erosion. The most extensive retreat has occurred along the low-lying dissipative north shore of the lake. Measured shoreline retreat along the north shore is compared to the retreat predicted by the Bruun Rule. The Bruun Rule under-predicted the actual measured shoreline retreat by as much as an order of magnitude. The redistribution of annual wave energy due to regulated lake level fluctuation is the main factor contributing to erosion, a factor that is not accounted for with the Bruun Rule. Therefore the redistribution of annual incident wave energy is examined in terms of an increased transgression time, a reduced range in lake level fluctuation, and an elevated lake level. Both transgression time and range in water level fluctuation affect the distribution of incident wave energy and were found to be more important to shoreline erosion than an elevated water level. An alternative regulation scheme incorporating both concerns for hydropower production and lake regulation is proposed and examined in terms of reducing erosion. Altering the transgression time of lake level fluctuation by changing the timing and increasing the rate of lake level drawdown, results in a significant reduction in the amount of annual wave energy that reaches the eroding full pool shoreline, thereby reducing the potential for shoreline erosion lake-wide. A lowered regulated full pooi lake level would decrease the intensity of overwash further reducing shoreline retreat related to that process of erosion. Natural gravel beaches can provide the backshore of coastal environments with a protective buffer from wave erosion. A case study is presented of the conceptual design and utility of an artificial perched gravel beach used to stabilize an eroding backshore on the reflective east shore of the lake. Boulders and cobbles were used as a stable platform to perch beach gravels above the previously eroding profile. A longshore exchange of gravel within the beach compartment was incorporated into the conceptual design. The structure has performed successfully during the three year monitoring period as exemplified by the lack of backshore erosion and the maintenance of the perched profile. Close

• 1783. [Article] Competitive interactions and resource partitioning between northern spotted owls and barred owls in western Oregon

  The federally threatened northern spotted owl (Strix occidentalis caurina) is the focus of intensive conservation efforts that have led to much forested land being reserved as habitat for the owl and associated ...

  Citation × Citation Citation Abstract Copy Title: Competitive interactions and resource partitioning between northern spotted owls and barred owls in western Oregon Author: Wiens, J. David The federally threatened northern spotted owl (Strix occidentalis caurina) is the focus of intensive conservation efforts that have led to much forested land being reserved as habitat for the owl and associated wildlife species throughout the Pacific Northwest of the United States. Recently, however, a relatively new threat to spotted owls has emerged in the form of an invasive competitor: the congeneric barred owl (Strix varia). As barred owls have rapidly expanded their populations into the entire range of the northern spotted owl, mounting evidence indicates that they are displacing, hybridizing with, and even killing spotted owls. The barred owl invasion into western North America has made an already complex conservation issue even more contentious, and a lack of information on the ecological relationships between the 2 species has hampered conservation efforts. During 2007–2009 I investigated spatial relationships, habitat selection, diets, survival, and reproduction of sympatric spotted owls and barred owls in western Oregon, USA. My overall objective was to determine the potential for and possible consequences of competition for space, habitat, and food between the 2 species. My study included 29 spotted owls and 28 barred owls that were radio-marked in 36 neighboring territories and monitored over a 24-month tracking period. Based on repeated surveys of both species, the number of territories occupied by pairs of barred owls in the 745 km² study area (82) greatly outnumbered those occupied by pairs of spotted owls (15). Estimates of mean size of home-ranges and core-use areas of spotted owls (1,843 ha and 305 ha, respectively) were 2–4 times larger than those of barred owls (581 ha and 188 ha, respectively). Individual spotted and barred owls in adjacent territories often had overlapping home ranges, but inter-specific space sharing was largely restricted to broader foraging areas in the home range with minimal spatial overlap among core-use areas. I used an information-theoretic approach to rank discrete choice models representing alternative hypotheses about the influence of forest conditions and interspecific interactions on species-specific patterns of nighttime habitat selection. Spotted owls spent a disproportionate amount of time foraging on steep slopes in ravines dominated by old (>120 yrs old) conifer trees. Barred owls used available forest types more evenly than spotted owls, and were most strongly associated with patches of large hardwood and conifer trees that occupied relatively flat areas along streams. Spotted and barred owls differed in the relative use of old conifer forest (higher for spotted owls) and slope conditions (steeper slopes for spotted owls). I found no evidence that the 2 species differed in their use of young, mature, and riparian-hardwood forest types, and both species avoided forest-nonforest edges. The best resource selection function for spotted owls indicated that the relative probability of a location being selected was reduced if the location was within or in close proximity to a core-use area of a barred owl. I used pellet analysis and measures of food niche overlap to examine the potential for dietary competition between spatially associated pairs of spotted owls and barred owls. I identified 1,223 prey items from 15 territories occupied by pairs of spotted owls and 4,299 prey items from 24 territories occupied by pairs of barred owls. Diets of both species were dominated by nocturnal mammals, but diets of barred owls included many terrestrial, aquatic, and diurnal prey species that were rare or absent in diets of spotted owls. Northern flying squirrels (Glaucomys sabrinus), woodrats (Neotoma fuscipes, N. cinerea), and lagomorphs (Lepus americanus, Sylvilagus bachmani) were particularly important prey for both owl species, accounting for 81% and 49% of total dietary biomass for spotted owls and barred owls, respectively. Dietary overlap between pairs of spotted and barred owls in adjacent territories ranged from 28–70% (mean = 42%) In addition to overlap in resource use, I also identified strong associations between the presence of barred owls and the behavior of spotted owls, as shown by changes in space-use, habitat selection, and reproductive output of spotted owls exposed to different levels of spatial overlap with barred owls in adjacent territories. Barred owls in my study area displayed both numeric and demographic superiority over spotted owls; the annual survival probability of radio-marked spotted owls from known-fate analyses (0.81, SE = 0.05) was lower than that of barred owls (0.92, SE = 0.04), and barred owls produced over 6 times as many young over a 3-year period as spotted owls. Survival of both species was positively associated with an increasing proportion of old (>120 yrs old) conifer forest within the home range, which suggested that availability of old forest was a potential limiting factor in the competitive relationship between the 2 species. When viewed collectively, my results support the hypothesis that interference competition with a high density of barred owls for territorial space can act to constrain the availability of critical resources required for successful recruitment and reproduction of spotted owls. My findings have broad implications for the conservation of spotted owls, as they suggest that spatial heterogeneity in survival and reproduction may arise not only because of differences among territories in the quality of forest habitat, but also because of the spatial distribution of an invasive competitor. Title: Competitive interactions and resource partitioning between northern spotted owls and barred owls in western Oregon Author: Wiens, J. David The federally threatened northern spotted owl (Strix occidentalis caurina) is the focus of intensive conservation efforts that have led to much forested land being reserved as habitat for the owl and associated wildlife species throughout the Pacific Northwest of the United States. Recently, however, a relatively new threat to spotted owls has emerged in the form of an invasive competitor: the congeneric barred owl (Strix varia). As barred owls have rapidly expanded their populations into the entire range of the northern spotted owl, mounting evidence indicates that they are displacing, hybridizing with, and even killing spotted owls. The barred owl invasion into western North America has made an already complex conservation issue even more contentious, and a lack of information on the ecological relationships between the 2 species has hampered conservation efforts. During 2007–2009 I investigated spatial relationships, habitat selection, diets, survival, and reproduction of sympatric spotted owls and barred owls in western Oregon, USA. My overall objective was to determine the potential for and possible consequences of competition for space, habitat, and food between the 2 species. My study included 29 spotted owls and 28 barred owls that were radio-marked in 36 neighboring territories and monitored over a 24-month tracking period. Based on repeated surveys of both species, the number of territories occupied by pairs of barred owls in the 745 km² study area (82) greatly outnumbered those occupied by pairs of spotted owls (15). Estimates of mean size of home-ranges and core-use areas of spotted owls (1,843 ha and 305 ha, respectively) were 2–4 times larger than those of barred owls (581 ha and 188 ha, respectively). Individual spotted and barred owls in adjacent territories often had overlapping home ranges, but inter-specific space sharing was largely restricted to broader foraging areas in the home range with minimal spatial overlap among core-use areas. I used an information-theoretic approach to rank discrete choice models representing alternative hypotheses about the influence of forest conditions and interspecific interactions on species-specific patterns of nighttime habitat selection. Spotted owls spent a disproportionate amount of time foraging on steep slopes in ravines dominated by old (>120 yrs old) conifer trees. Barred owls used available forest types more evenly than spotted owls, and were most strongly associated with patches of large hardwood and conifer trees that occupied relatively flat areas along streams. Spotted and barred owls differed in the relative use of old conifer forest (higher for spotted owls) and slope conditions (steeper slopes for spotted owls). I found no evidence that the 2 species differed in their use of young, mature, and riparian-hardwood forest types, and both species avoided forest-nonforest edges. The best resource selection function for spotted owls indicated that the relative probability of a location being selected was reduced if the location was within or in close proximity to a core-use area of a barred owl. I used pellet analysis and measures of food niche overlap to examine the potential for dietary competition between spatially associated pairs of spotted owls and barred owls. I identified 1,223 prey items from 15 territories occupied by pairs of spotted owls and 4,299 prey items from 24 territories occupied by pairs of barred owls. Diets of both species were dominated by nocturnal mammals, but diets of barred owls included many terrestrial, aquatic, and diurnal prey species that were rare or absent in diets of spotted owls. Northern flying squirrels (Glaucomys sabrinus), woodrats (Neotoma fuscipes, N. cinerea), and lagomorphs (Lepus americanus, Sylvilagus bachmani) were particularly important prey for both owl species, accounting for 81% and 49% of total dietary biomass for spotted owls and barred owls, respectively. Dietary overlap between pairs of spotted and barred owls in adjacent territories ranged from 28–70% (mean = 42%) In addition to overlap in resource use, I also identified strong associations between the presence of barred owls and the behavior of spotted owls, as shown by changes in space-use, habitat selection, and reproductive output of spotted owls exposed to different levels of spatial overlap with barred owls in adjacent territories. Barred owls in my study area displayed both numeric and demographic superiority over spotted owls; the annual survival probability of radio-marked spotted owls from known-fate analyses (0.81, SE = 0.05) was lower than that of barred owls (0.92, SE = 0.04), and barred owls produced over 6 times as many young over a 3-year period as spotted owls. Survival of both species was positively associated with an increasing proportion of old (>120 yrs old) conifer forest within the home range, which suggested that availability of old forest was a potential limiting factor in the competitive relationship between the 2 species. When viewed collectively, my results support the hypothesis that interference competition with a high density of barred owls for territorial space can act to constrain the availability of critical resources required for successful recruitment and reproduction of spotted owls. My findings have broad implications for the conservation of spotted owls, as they suggest that spatial heterogeneity in survival and reproduction may arise not only because of differences among territories in the quality of forest habitat, but also because of the spatial distribution of an invasive competitor. Close

• 1784. [Article] Forestry

  Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2009. All rights reserved.

  Citation × Citation Citation Abstract Copy Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2009. All rights reserved. Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2009. All rights reserved. Close

• 1785. [Article] Forestry

  Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2007. All rights reserved.

  Citation × Citation Citation Abstract Copy Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2007. All rights reserved. Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2007. All rights reserved. Close

• 1786. [Article] Forestry

  Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2011. All rights reserved.

  Citation × Citation Citation Abstract Copy Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2011. All rights reserved. Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2011. All rights reserved. Close

• 1787. [Article] Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire

  Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as ...

  Citation × Citation Citation Abstract Copy Title: Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire Author: Foster, Lee (Lee Jacob) Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern in western North America. The distribution of the species has been reduced by approximately half since European settlement, with concurrent and continuing population declines across its occupied range. The primary threats to the species are habitat alteration and loss, caused by multiple factors. In the western portion of its distribution, increasing wildfire activity is a primary cause of habitat loss and degradation. Single wildfires in this area may now reach extremely large sizes (>100,000 ha), and wildfires have been linked to local population declines. However, no published studies, to date, have examined the immediate effects of large-scale wildfire on sage-grouse habitat selection and demographic rates, using modern telemetry methods. I studied the habitat selection patterns, nest success, and survival of adult, and yearling female sage-grouse, captured within or near the Holloway fire, using state-of-the-art GPS-PTT telemetry methods. The Holloway fire burned ~187,000 ha of highly productive sage-grouse habitat in August, 2012. My study began during the first spring post-fire (March, 2013), and continued through February, 2015. I monitored seasonal habitat use patterns, and site-fidelity of sage-grouse, and modeled third-order seasonal resource selection, using mixed effects resource selection functions, in relation to characteristics of the post-fire habitat mosaic, terrain, mesic habitat availability, and herbaceous vegetation regeneration. I described sage-grouse nesting habitat use, nesting effort, and modeled daily nest survival in relation to temporal patterns, patch scale vegetation, biological factors, and landscape-scale habitat composition. I modeled adult and yearling female sage-grouse survival in relation to temporal patterns, biological factors, and landscape-scale habitat composition. Female sage-grouse primarily exhibited a three range seasonal movement pattern, with differentiation between breeding-nesting-early brood-rearing habitat (mean use dates: 8 Mar - 12 Jun), late brood-rearing-summer habitat (13 Jun - 20 Oct), and winter habitat (21 Oct - 7 Mar). However there was variation in seasonal range behavior among individuals. Sage-grouse exhibited considerable fidelity to all seasonal ranges, for individuals which survived >1 yr, mean distance between seasonal range centroids of the same type were 1.80 km, 1.65 km, and 3.96 km, for breeding ranges, summer ranges, and winter ranges, respectively. Within seasonal ranges, sage-grouse exhibited third-order resource selection patterns similar to those observed for populations in undisturbed habitats. Sage-grouse, at the population level, selected for level terrain throughout the year. During the breeding season sage-grouse selected for areas with increased amounts of intact sagebrush land-cover within a 1-km² area around used locations, areas of increased NDVI values within a 6.25-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and mid-level elevations. During summer, sage-grouse, at the population level, selected for an areas with an intermediate density of burned-intact habitat edge within a 1 km² area, areas of increased NDVI values within a 6.25-km² area, intermediate distances to mesic habitat, and high elevations. During winter, sage-grouse, at the population level, selected for increased amounts of intact sagebrush land-cover within a 0.089-km² area, areas with decreased variation in NDVI within a 0.089-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and intermediate elevations. There was considerable variation in third-order resource selection patterns among individuals during all seasons. Sage-grouse nest success was consistently low during the study (2013: 19.3%, 2014: 30.1%), and nest initiation rates were average to high (2013: 1st nest initiation = 90.5%, 2nd nest initiation = 23.1%; 2014: 1st nest initiation = 100%, 2nd nest initiation = 57.1%). Daily nest survival rates were influenced by an interaction between year and nesting attempt, and by forb cover within 5 m of the nest. Nest survival over the incubation period was consistently low for 1st and 2nd nests during 2013, and for 1st nests during 2014 (range: 0.131 - 0.212), but increased to 0.744 for 2nd nests during 2014. Forb cover within 5 m of the nest had a positive effect on daily nest survival rates, with a 1% increase in forb cover increasing the probability of a nest surviving a given day by 1.02 times. We did not detect strong direct effects of habitat or biological characteristics on survival of adult and yearling female sage-grouse. Rather, survival varied by month with lowest survival occurring in April and August of each year, and highest survival occurring during the winter. While patterns of monthly survival were similar between years, there was a strong, negative additive effect on survival which extended from the beginning of the study (March, 2013), through the end of the first post fire growing season (July, 2013). Although monthly survival increased following the end of the 1st post-fire growing season, yearly survival over both the 1st and 2nd biological years post-fire was low (March 2013 - February 2014: 24.0%; March 2014 - February 2015: 37.9%). These results indicate that female greater-sage grouse do not respond to wildfire related habitat disturbance through emigration, and rather continue to attempt to exist and reproduce in habitats disturbed by wildfire during the immediate years following a fire. While, due to site-fidelity, sage-grouse are not able to leave wildfire affected seasonal ranges, within those seasonal ranges they still attempt to utilize habitat components which most closely match their life-history requirements. However, this behavior appears to have an acute fitness cost to individuals, with reduced nesting success and survival of individuals utilizing fire-affected habitats during the first two years post-fire. This reduction in demographic rates likely explains observed sage-grouse population declines following wildfire, and indicates that these population declines are not the result of sage-grouse emigration away from fire-affected leks, but rather a true decline in the number of individual sage-grouse on the landscape following large-scale wildfire. Title: Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire Author: Foster, Lee (Lee Jacob) Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern in western North America. The distribution of the species has been reduced by approximately half since European settlement, with concurrent and continuing population declines across its occupied range. The primary threats to the species are habitat alteration and loss, caused by multiple factors. In the western portion of its distribution, increasing wildfire activity is a primary cause of habitat loss and degradation. Single wildfires in this area may now reach extremely large sizes (>100,000 ha), and wildfires have been linked to local population declines. However, no published studies, to date, have examined the immediate effects of large-scale wildfire on sage-grouse habitat selection and demographic rates, using modern telemetry methods. I studied the habitat selection patterns, nest success, and survival of adult, and yearling female sage-grouse, captured within or near the Holloway fire, using state-of-the-art GPS-PTT telemetry methods. The Holloway fire burned ~187,000 ha of highly productive sage-grouse habitat in August, 2012. My study began during the first spring post-fire (March, 2013), and continued through February, 2015. I monitored seasonal habitat use patterns, and site-fidelity of sage-grouse, and modeled third-order seasonal resource selection, using mixed effects resource selection functions, in relation to characteristics of the post-fire habitat mosaic, terrain, mesic habitat availability, and herbaceous vegetation regeneration. I described sage-grouse nesting habitat use, nesting effort, and modeled daily nest survival in relation to temporal patterns, patch scale vegetation, biological factors, and landscape-scale habitat composition. I modeled adult and yearling female sage-grouse survival in relation to temporal patterns, biological factors, and landscape-scale habitat composition. Female sage-grouse primarily exhibited a three range seasonal movement pattern, with differentiation between breeding-nesting-early brood-rearing habitat (mean use dates: 8 Mar - 12 Jun), late brood-rearing-summer habitat (13 Jun - 20 Oct), and winter habitat (21 Oct - 7 Mar). However there was variation in seasonal range behavior among individuals. Sage-grouse exhibited considerable fidelity to all seasonal ranges, for individuals which survived >1 yr, mean distance between seasonal range centroids of the same type were 1.80 km, 1.65 km, and 3.96 km, for breeding ranges, summer ranges, and winter ranges, respectively. Within seasonal ranges, sage-grouse exhibited third-order resource selection patterns similar to those observed for populations in undisturbed habitats. Sage-grouse, at the population level, selected for level terrain throughout the year. During the breeding season sage-grouse selected for areas with increased amounts of intact sagebrush land-cover within a 1-km² area around used locations, areas of increased NDVI values within a 6.25-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and mid-level elevations. During summer, sage-grouse, at the population level, selected for an areas with an intermediate density of burned-intact habitat edge within a 1 km² area, areas of increased NDVI values within a 6.25-km² area, intermediate distances to mesic habitat, and high elevations. During winter, sage-grouse, at the population level, selected for increased amounts of intact sagebrush land-cover within a 0.089-km² area, areas with decreased variation in NDVI within a 0.089-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and intermediate elevations. There was considerable variation in third-order resource selection patterns among individuals during all seasons. Sage-grouse nest success was consistently low during the study (2013: 19.3%, 2014: 30.1%), and nest initiation rates were average to high (2013: 1st nest initiation = 90.5%, 2nd nest initiation = 23.1%; 2014: 1st nest initiation = 100%, 2nd nest initiation = 57.1%). Daily nest survival rates were influenced by an interaction between year and nesting attempt, and by forb cover within 5 m of the nest. Nest survival over the incubation period was consistently low for 1st and 2nd nests during 2013, and for 1st nests during 2014 (range: 0.131 - 0.212), but increased to 0.744 for 2nd nests during 2014. Forb cover within 5 m of the nest had a positive effect on daily nest survival rates, with a 1% increase in forb cover increasing the probability of a nest surviving a given day by 1.02 times. We did not detect strong direct effects of habitat or biological characteristics on survival of adult and yearling female sage-grouse. Rather, survival varied by month with lowest survival occurring in April and August of each year, and highest survival occurring during the winter. While patterns of monthly survival were similar between years, there was a strong, negative additive effect on survival which extended from the beginning of the study (March, 2013), through the end of the first post fire growing season (July, 2013). Although monthly survival increased following the end of the 1st post-fire growing season, yearly survival over both the 1st and 2nd biological years post-fire was low (March 2013 - February 2014: 24.0%; March 2014 - February 2015: 37.9%). These results indicate that female greater-sage grouse do not respond to wildfire related habitat disturbance through emigration, and rather continue to attempt to exist and reproduce in habitats disturbed by wildfire during the immediate years following a fire. While, due to site-fidelity, sage-grouse are not able to leave wildfire affected seasonal ranges, within those seasonal ranges they still attempt to utilize habitat components which most closely match their life-history requirements. However, this behavior appears to have an acute fitness cost to individuals, with reduced nesting success and survival of individuals utilizing fire-affected habitats during the first two years post-fire. This reduction in demographic rates likely explains observed sage-grouse population declines following wildfire, and indicates that these population declines are not the result of sage-grouse emigration away from fire-affected leks, but rather a true decline in the number of individual sage-grouse on the landscape following large-scale wildfire. Close

• 1788. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; September 1995

  Previously established field trials of MTTC-Fume continue to show that this chemical remains in Douglas-fir and southern pine poles at fungitoxic levels 5 years after treatment. In general, increasing ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; September 1995 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Previously established field trials of MTTC-Fume continue to show that this chemical remains in Douglas-fir and southern pine poles at fungitoxic levels 5 years after treatment. In general, increasing dosages resulted in higher chemical levels in the poles. All of the MITC-Fume treatments resulted in higher residual M1TC levels than comparable metham sodium treatments. Field trials with solid basaniid with and without copper sulfate continue to show the promise of this chemical. Basamid treated poles continue to contain MITC at levels which exceed those for comparable metham sodium treatments. These results, which are currently being confirmed in poles in service, indicate that this formulation can deliver fiingitoxic MITC levels to wood in service, without the risk of spills associated with metham sodium. We have completed trials with gelled and pelletized metham sodium formulations. Both of these formulations offered improved safety during application. Initial laboratory trials also suggested that the gelled formulation was more effective than comparable liquid metham sodium. Field trials, however, indicate that the formulations provided protection comparable to the liquid formulation in poles over the test period. The gelled formulation still offers the advantage of reduced risks of spills during application. Trials are also continuing with various solid, water diffusible treatments for arresting internal decay. Trials of fused borate rods continue to show that these treatments require more moisture for effective movement in Douglas-fir poles. Field trials have also been established with borate rods with glycol as an additive to determine if glycols can accelerate diffusion in drier wood. The poles in these trials have also been sensored to monitor internal moisture changes over time in order to better correlate boron diffusion with wood moisture content. Trials underway with a boronlfluoride rod indicate that the boron is diffusing well from these rods, while the fluoride is moving somewhat slower. Neither chemical has approached a fiungal threshold one year after treatment, but the combination of chemicals may lead to more effective fungal control. Trials with pelletized metham sodium/basamid mixtures suggests that using ratios of these two chemicals can produce an initial rapid burst ofMITC release followed by a slower MITC release with time. This combination allows for rapid control of existing fungal infestations followed by long term protection against reinvasion. These laboratory trials will be further confirmed with field trials. The trials to evaluate the effects of voids on fumigant movement initially suggested that voids have little influence on subsequent fumigant levels on either side of the void. Sampling 8 years after treatment, however, indicates that chioropicrin levels were generally higher in poles without voids. We plan further trials of actual field poles containing voids to confirm these effects. Trials to identify treatments for protecting the sapwood of western redcedar poles as well as wood exposed in field drilled bolt holes are continuing. Trials in western redcedar sapwood have identified a number of chemicals which can be remedially applied to protect this wood against fungal attack. At present, however, commercial pole spraying has largely ceased making further field trials difficult. Field trials to identify treatments for protecting untreated wood exposed during drilling for various pole attachments continue to show that diffusible boron and fluoride compounds provide excellent long term protection against flingal attack. The protective effects of one diffusible treatment, Boracol, however, has begun to decline. Further sampling will be undertaken to identify the long term effectiveness of the remaining treatments. Trials to identify enhanced patterns for through boring of Douglas-fir poles are complete. The results indicate that patterns as widely spaced as 400 mm apart longitudinally still produce a nearly completely treated pole i n the through bored zone. Pentachlorophenol levels in the through bored zone were generally above the threshold for ftrngal growth. Prior sampling of Douglas-fir poles in service suggest that even poles with small skips in the through bored zone contained no evidence of internal decay. These results suggest that the through boring pattern can be extended without adversely risking pole service life. A reduced through boring pattern would decrease treatment costs while minimizing impacts on pole strength. Trials to evaluate the application of boron to freshly peeled Douglas-fir poles as a means of preventing fungal colonization using a thermal process suggest that thermal treatment failed to produce a boron loading sufilcient to permit subsequent diffusion across the pole section after a 3 month diffusion period. Evaluations of various external groundline preservative formulations continue to indicate that replacement formulations based upon copper naphthenate, boron or fluoride perform comparably to earlier formulations employing pentachlorophenol and creosote. Pentachlorophenol levels in some treatments have fallen below the threshold for fungal growth, while those in all of the replacement treatments remain above a U protective level. These results suggest that the newer groundline preservative systems should provide a reasonable level of protection against external decay. Laboratory trials to better understand the levels of combinations of chemicals required for protection in the groundline zone are continuing. Fungal cellar evaluations of copper naphthenate treated western redcedar continue to show excellent performance at levels specified in the American Wood Preservers' Association Standards. Performance is generally better for wood which was freshly sawn prior to treatment, while wood cuts from weathered poles in service has provided slightly lower levels of protection. The weather wood apparently has higher permeability, making it more likely to lose chemical in soil contact. Further evaluations are planned. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; September 1995 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Previously established field trials of MTTC-Fume continue to show that this chemical remains in Douglas-fir and southern pine poles at fungitoxic levels 5 years after treatment. In general, increasing dosages resulted in higher chemical levels in the poles. All of the MITC-Fume treatments resulted in higher residual M1TC levels than comparable metham sodium treatments. Field trials with solid basaniid with and without copper sulfate continue to show the promise of this chemical. Basamid treated poles continue to contain MITC at levels which exceed those for comparable metham sodium treatments. These results, which are currently being confirmed in poles in service, indicate that this formulation can deliver fiingitoxic MITC levels to wood in service, without the risk of spills associated with metham sodium. We have completed trials with gelled and pelletized metham sodium formulations. Both of these formulations offered improved safety during application. Initial laboratory trials also suggested that the gelled formulation was more effective than comparable liquid metham sodium. Field trials, however, indicate that the formulations provided protection comparable to the liquid formulation in poles over the test period. The gelled formulation still offers the advantage of reduced risks of spills during application. Trials are also continuing with various solid, water diffusible treatments for arresting internal decay. Trials of fused borate rods continue to show that these treatments require more moisture for effective movement in Douglas-fir poles. Field trials have also been established with borate rods with glycol as an additive to determine if glycols can accelerate diffusion in drier wood. The poles in these trials have also been sensored to monitor internal moisture changes over time in order to better correlate boron diffusion with wood moisture content. Trials underway with a boronlfluoride rod indicate that the boron is diffusing well from these rods, while the fluoride is moving somewhat slower. Neither chemical has approached a fiungal threshold one year after treatment, but the combination of chemicals may lead to more effective fungal control. Trials with pelletized metham sodium/basamid mixtures suggests that using ratios of these two chemicals can produce an initial rapid burst ofMITC release followed by a slower MITC release with time. This combination allows for rapid control of existing fungal infestations followed by long term protection against reinvasion. These laboratory trials will be further confirmed with field trials. The trials to evaluate the effects of voids on fumigant movement initially suggested that voids have little influence on subsequent fumigant levels on either side of the void. Sampling 8 years after treatment, however, indicates that chioropicrin levels were generally higher in poles without voids. We plan further trials of actual field poles containing voids to confirm these effects. Trials to identify treatments for protecting the sapwood of western redcedar poles as well as wood exposed in field drilled bolt holes are continuing. Trials in western redcedar sapwood have identified a number of chemicals which can be remedially applied to protect this wood against fungal attack. At present, however, commercial pole spraying has largely ceased making further field trials difficult. Field trials to identify treatments for protecting untreated wood exposed during drilling for various pole attachments continue to show that diffusible boron and fluoride compounds provide excellent long term protection against flingal attack. The protective effects of one diffusible treatment, Boracol, however, has begun to decline. Further sampling will be undertaken to identify the long term effectiveness of the remaining treatments. Trials to identify enhanced patterns for through boring of Douglas-fir poles are complete. The results indicate that patterns as widely spaced as 400 mm apart longitudinally still produce a nearly completely treated pole i n the through bored zone. Pentachlorophenol levels in the through bored zone were generally above the threshold for ftrngal growth. Prior sampling of Douglas-fir poles in service suggest that even poles with small skips in the through bored zone contained no evidence of internal decay. These results suggest that the through boring pattern can be extended without adversely risking pole service life. A reduced through boring pattern would decrease treatment costs while minimizing impacts on pole strength. Trials to evaluate the application of boron to freshly peeled Douglas-fir poles as a means of preventing fungal colonization using a thermal process suggest that thermal treatment failed to produce a boron loading sufilcient to permit subsequent diffusion across the pole section after a 3 month diffusion period. Evaluations of various external groundline preservative formulations continue to indicate that replacement formulations based upon copper naphthenate, boron or fluoride perform comparably to earlier formulations employing pentachlorophenol and creosote. Pentachlorophenol levels in some treatments have fallen below the threshold for fungal growth, while those in all of the replacement treatments remain above a U protective level. These results suggest that the newer groundline preservative systems should provide a reasonable level of protection against external decay. Laboratory trials to better understand the levels of combinations of chemicals required for protection in the groundline zone are continuing. Fungal cellar evaluations of copper naphthenate treated western redcedar continue to show excellent performance at levels specified in the American Wood Preservers' Association Standards. Performance is generally better for wood which was freshly sawn prior to treatment, while wood cuts from weathered poles in service has provided slightly lower levels of protection. The weather wood apparently has higher permeability, making it more likely to lose chemical in soil contact. Further evaluations are planned. Close

• 1789. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992

  Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection afforded by these treatments has declined with time, residual fungitoxic levels remain in many tests. Field trials of gelatin encapsulated MITC indicate that gelatin had no negative effect on fumigant performance even when no water was added at the time of treatment. Closed tube bioassays, chemical analyses, and culturing of Douglas-fir and southern pine poles treated with glass encapsulated METC (MITC-Fume) indicate that this chemical is outperforming metham sodium 3 years after application. While the glass vials lost chemical very slowly, the slow release rate did not appear to adversely affect MITC performance. Trials to evaluate the performance of fused borate rods were sampled after 1 or 2 years of exposure. Chemical analysis of cores removed from the test poles revealed that none of the treatments contained boron at levels which would be considered adequate for arresting or preventing colonization by wood decay fungi. Interestingly, boron levels in poles exposed in Hilo, Hawaii were highest above the treatment hole, suggesting that some upward diffusion of this chemical is possible. The low boron levels in these poles are reason for concern, since a number of utilities are considering the using this formulation for remedial treatment at the groundline. Evaluations of new solid fumigants are progressing. Trials with Basamid indicate that the addition of copper compounds improved the rate of decomposition to produce MITC. Simultaneous addition of copper sulfate and Basamid may be useful for accelerating the decomposition of this compound, making it practical for control of internal decay fungi. Trials have been established to evaluate the performance of gelled and pelletized metham sodium and a sodium fluoride/boron rod. These trials will be evaluated in future reports. A third field trial to evaluate the performance of a copper naphthenate/boron paste for internal treatment of Douglas-fir poles is currently be evaluated to determine chemical levels 3 years after treatment. The performance of gelled metham sodium was further evaluated under laboratory conditions to better understand the performance of this chemical. Gelled metham sodium provided improved fungal control in comparison with liquid metham sodium and appeared to produce increased MITC levels under a variety of test conditions. The improved performance of this formulation may reflect the ability of the gell to retain moisture for longer periods of time than the liquid metham sodium formulation. Further studies of this formulation are underway. Laboratory studies were also performed to evaluate the effects of various additives on the performance of Basamid. Once again, the addition of copper compounds enhanced the production of MITC. A number of other compounds shifted decomposition to the production of carbon disulfide and carbonyl sulfide, two less fungitoxic compounds. Further studies are underway to identify non-sulfur products which may provide some protection against wood decay fungi. Evaluations of the effects of artificial voids on performance of fumigants in Douglas-fir poles indicate that voids had little or no effect on fumigant distribution. As a result, fumigant treatment of solid wood around voids represents a viable strategy for improving pole service life. Evaluation of timbers treated with metham sodium indicate that detectable levels of MITC were present one year after treatment. These timbers will be evaluated in subsequent years to determine the protective period provided by fumigants in sawn material. We continue development of a fumigant movement model using data previously developed on MITC. This year, we evaluated a previously developed system, ANSYS. Results of preliminary trials are similar to data previously developed on MITC-Fume treated poles and indicate that modeling MITC movement should be possible. Further trials are underway to confirm and expand this model. The effect of wood moisture content, temperature and wood species on metham sodium decomposition was investigated under laboratory conditions. The efficiency of dcomposition to MITC varied widely, but was most affected by temperature and wood moisture content. The results suggests that there is considerable potential for improving decomposition efficiency to enhance performance of this fumigant. Further studies to characterize the relationship between chemical content of the wood species and decomposition are underway. Field trials to identify safer treatments for preventing decay of cedar sapwood and protecting field drilled bolt holes are continuing. Diffusible treatments continue to provide excellent protection for field drilled bolt holes. A study to develop estimates of the extent of decay above the groundline in Douglas-fir poles in the Pacific Northwest is underway. The data from this study will be used to develop estimates of the potential for damage and provide some insight into the extent of this problem. Studies to develop guidelines for sterilization of Douglas-fir poles following air-seasoning are continuing. Evaluations of internal temperature development during kiln-drying were completed this year and indicate that internal temperatures during typical pole drying schedules were more than adequate for acheiving sterilization. Further evaluations of the data are underway to develop reliable heating curves for this process. Evaluations of groundline preservative systems have been established at Corvallis, OR and Merced, CA. The results indicate that all of the formulations are moving well through the wood in a manner similar to that found with pentachlorophenol-based systems. Chemical levels in some treatments; however, are beginning to decline 30 months after treatment. Studies are now underway to establish thresholds for combinations of the various formulations. Copper naphthenate treated western redcedar stakelets continue to perform well in fungus cellar trials. Stakes weathered prior to treatment are degrading slightly faster, while freshly sawn stakelets continue to perform well. Field trials have also been established to evaluate the performance of copper naphthenate treated Douglas-fir utility poles in California and Oregon. The chemical levels and fungal colonization will be monitored in these poles to provide a guide to performance of this chemical in western wood species. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection afforded by these treatments has declined with time, residual fungitoxic levels remain in many tests. Field trials of gelatin encapsulated MITC indicate that gelatin had no negative effect on fumigant performance even when no water was added at the time of treatment. Closed tube bioassays, chemical analyses, and culturing of Douglas-fir and southern pine poles treated with glass encapsulated METC (MITC-Fume) indicate that this chemical is outperforming metham sodium 3 years after application. While the glass vials lost chemical very slowly, the slow release rate did not appear to adversely affect MITC performance. Trials to evaluate the performance of fused borate rods were sampled after 1 or 2 years of exposure. Chemical analysis of cores removed from the test poles revealed that none of the treatments contained boron at levels which would be considered adequate for arresting or preventing colonization by wood decay fungi. Interestingly, boron levels in poles exposed in Hilo, Hawaii were highest above the treatment hole, suggesting that some upward diffusion of this chemical is possible. The low boron levels in these poles are reason for concern, since a number of utilities are considering the using this formulation for remedial treatment at the groundline. Evaluations of new solid fumigants are progressing. Trials with Basamid indicate that the addition of copper compounds improved the rate of decomposition to produce MITC. Simultaneous addition of copper sulfate and Basamid may be useful for accelerating the decomposition of this compound, making it practical for control of internal decay fungi. Trials have been established to evaluate the performance of gelled and pelletized metham sodium and a sodium fluoride/boron rod. These trials will be evaluated in future reports. A third field trial to evaluate the performance of a copper naphthenate/boron paste for internal treatment of Douglas-fir poles is currently be evaluated to determine chemical levels 3 years after treatment. The performance of gelled metham sodium was further evaluated under laboratory conditions to better understand the performance of this chemical. Gelled metham sodium provided improved fungal control in comparison with liquid metham sodium and appeared to produce increased MITC levels under a variety of test conditions. The improved performance of this formulation may reflect the ability of the gell to retain moisture for longer periods of time than the liquid metham sodium formulation. Further studies of this formulation are underway. Laboratory studies were also performed to evaluate the effects of various additives on the performance of Basamid. Once again, the addition of copper compounds enhanced the production of MITC. A number of other compounds shifted decomposition to the production of carbon disulfide and carbonyl sulfide, two less fungitoxic compounds. Further studies are underway to identify non-sulfur products which may provide some protection against wood decay fungi. Evaluations of the effects of artificial voids on performance of fumigants in Douglas-fir poles indicate that voids had little or no effect on fumigant distribution. As a result, fumigant treatment of solid wood around voids represents a viable strategy for improving pole service life. Evaluation of timbers treated with metham sodium indicate that detectable levels of MITC were present one year after treatment. These timbers will be evaluated in subsequent years to determine the protective period provided by fumigants in sawn material. We continue development of a fumigant movement model using data previously developed on MITC. This year, we evaluated a previously developed system, ANSYS. Results of preliminary trials are similar to data previously developed on MITC-Fume treated poles and indicate that modeling MITC movement should be possible. Further trials are underway to confirm and expand this model. The effect of wood moisture content, temperature and wood species on metham sodium decomposition was investigated under laboratory conditions. The efficiency of dcomposition to MITC varied widely, but was most affected by temperature and wood moisture content. The results suggests that there is considerable potential for improving decomposition efficiency to enhance performance of this fumigant. Further studies to characterize the relationship between chemical content of the wood species and decomposition are underway. Field trials to identify safer treatments for preventing decay of cedar sapwood and protecting field drilled bolt holes are continuing. Diffusible treatments continue to provide excellent protection for field drilled bolt holes. A study to develop estimates of the extent of decay above the groundline in Douglas-fir poles in the Pacific Northwest is underway. The data from this study will be used to develop estimates of the potential for damage and provide some insight into the extent of this problem. Studies to develop guidelines for sterilization of Douglas-fir poles following air-seasoning are continuing. Evaluations of internal temperature development during kiln-drying were completed this year and indicate that internal temperatures during typical pole drying schedules were more than adequate for acheiving sterilization. Further evaluations of the data are underway to develop reliable heating curves for this process. Evaluations of groundline preservative systems have been established at Corvallis, OR and Merced, CA. The results indicate that all of the formulations are moving well through the wood in a manner similar to that found with pentachlorophenol-based systems. Chemical levels in some treatments; however, are beginning to decline 30 months after treatment. Studies are now underway to establish thresholds for combinations of the various formulations. Copper naphthenate treated western redcedar stakelets continue to perform well in fungus cellar trials. Stakes weathered prior to treatment are degrading slightly faster, while freshly sawn stakelets continue to perform well. Field trials have also been established to evaluate the performance of copper naphthenate treated Douglas-fir utility poles in California and Oregon. The chemical levels and fungal colonization will be monitored in these poles to provide a guide to performance of this chemical in western wood species. Close

• 1790. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; October 1996

  The Cooperative continues to actively address a diverse array of issues related to the effective use of wood utility poles. The trials to evaluate the effectiveness of MITC-Fume are now in their seventh ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; October 1996 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) The Cooperative continues to actively address a diverse array of issues related to the effective use of wood utility poles. The trials to evaluate the effectiveness of MITC-Fume are now in their seventh year and continue to show that methylisothiocyanate (MITC) levels in MITC-Fume treatments remain higher than comparable metham sodium treatments. The levels of chemical are, however, declining, suggesting that this treatment may need replenishment in 3 to 5 years. Trials with the solid wood fumigant Basamid continue to show that MITC release can be enhanced by addition of small amounts of copper. Field trials suggest that these additives become less important with time. As a result, unamended Basamid may be suitable for treatment where the risk of immediate decay is not high, but the utility wishes to protect against future attack. Field trials with various water-diffusible internal treatments continue to show that these treatments move more slowly through Douglas-fir heartwood than do fumigants. Boron levels in pole sections treated with fused borate rods remain at levels that will protect against fungal attack 6 years after treatment. Similar trials with a boron/ fluoride rod indicate that neither fluoride or boron levels in the poles are adequate for wood protection 2 years after treatment. While the dosages tested were relatively low, the volumes of chemical were similar to the liquid volumes normally applied during internal remedial treatment. We will sample these poles next year to ensure that our measurements accurately reflect the chemical levels present. Trials to evaluate the effects of glycol on boron movement from fused borate rods suggest that glycol enhanced boron diffusion to only a slight extent. This effect was most pronounced at lower moisture contents. This trial was established to identify methods for improving boron movement in drier wood. In addition, moisture measurements in these poles suggest the internal wood moisture content varies widely both seasonally and positionally. While elevated moisture levels can negatively affect the movement of gaseous fumigants, excess moisture is critical for diffusion of boron or fluoride and its absence around the treatment site can markedly reduce the efficacy of rod treatments. These poles will continue to be monitored to assess both boron movement and seasonal changes in moisture content. Trials to identify safe, effective and easily used systems for protecting wood exposed during field fabrication are continuing. Boron and fluoride continue to provide excellent protection to field drilled bolt holes. These treatments are safe and easy to apply, and have provided protection in our field test for 14 years. Trials of similar formulations on simulated decking are also reported to provide additional information on the ability of boron and fluoride to protect exposed Douglas-fir heartwood. Efforts to improve the effectiveness of through boring as a method for enhancing the treatment of Douglas-fir poles are continuing. This past year, we evaluated preservative distribution around through bored holes as a means of developing optimum through boring patterns that maximized treatment while minimizing potential strength effects. These trials suggest the diamond shaped through boring zone of effect is relatively narrow. This information will be used in the coming year to construct optimum patterns for poles of various classes. The goal of this project is to develop a standard through boring pattern that would permit automation of the process. This would create the potential for cost savings on new poles. Trials to evaluate the durability of western redcedar are nearly complete. These trials were initiated because of concerns that second growth western redcedar might be less durable than poles cut from older trees. As expected, cedar varied widely in its resistance to fungal attack. This resistance, however, was not related to tree age, suggesting that there might not be a difference between so-called "old-growth" and "second growth" material. These data will be more thoroughly analyzed once the final set of trials are completed. In addition, we are evaluating more rapid methods for assessing cedar durability by measuring tropolone content. Tropolones are an important component of the extractives that make cedar heartwood so durable. Field trials of various externally applied supplemental groundline treatments are continuing at sites in Oregon, California, and New York. Trials in Corvallis, Oregon, have shown that various copper naphthenate, fluoride or boron based systems are at least as effective as the pentachlorophenol (penta) based systems that were formerly used for this purpose. Penta concentrations in one system have now declined below a protective level, while the copper based systems continue to remain at a protective level. Field trials in California are following similar trends and indicate that the alternative systems will provide comparable performance. Fungus cellar trials of copper naphthenate treated western redcedar stakes continue to show that this chemical provides excellent protection to cedar sapwood. Weathered wood that was treated with copper naphthenate continues to perform more poorly than freshly sawn wood treated to similar retention levels. Variations in permeability likely account for these differences. A new Wood Pole Maintenance Manual has been completed and is now ready for distribution. This update of the 1979 publication includes more information on initial pole procurement and closely follows the video by the same name that we produced in 1994. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; October 1996 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) The Cooperative continues to actively address a diverse array of issues related to the effective use of wood utility poles. The trials to evaluate the effectiveness of MITC-Fume are now in their seventh year and continue to show that methylisothiocyanate (MITC) levels in MITC-Fume treatments remain higher than comparable metham sodium treatments. The levels of chemical are, however, declining, suggesting that this treatment may need replenishment in 3 to 5 years. Trials with the solid wood fumigant Basamid continue to show that MITC release can be enhanced by addition of small amounts of copper. Field trials suggest that these additives become less important with time. As a result, unamended Basamid may be suitable for treatment where the risk of immediate decay is not high, but the utility wishes to protect against future attack. Field trials with various water-diffusible internal treatments continue to show that these treatments move more slowly through Douglas-fir heartwood than do fumigants. Boron levels in pole sections treated with fused borate rods remain at levels that will protect against fungal attack 6 years after treatment. Similar trials with a boron/ fluoride rod indicate that neither fluoride or boron levels in the poles are adequate for wood protection 2 years after treatment. While the dosages tested were relatively low, the volumes of chemical were similar to the liquid volumes normally applied during internal remedial treatment. We will sample these poles next year to ensure that our measurements accurately reflect the chemical levels present. Trials to evaluate the effects of glycol on boron movement from fused borate rods suggest that glycol enhanced boron diffusion to only a slight extent. This effect was most pronounced at lower moisture contents. This trial was established to identify methods for improving boron movement in drier wood. In addition, moisture measurements in these poles suggest the internal wood moisture content varies widely both seasonally and positionally. While elevated moisture levels can negatively affect the movement of gaseous fumigants, excess moisture is critical for diffusion of boron or fluoride and its absence around the treatment site can markedly reduce the efficacy of rod treatments. These poles will continue to be monitored to assess both boron movement and seasonal changes in moisture content. Trials to identify safe, effective and easily used systems for protecting wood exposed during field fabrication are continuing. Boron and fluoride continue to provide excellent protection to field drilled bolt holes. These treatments are safe and easy to apply, and have provided protection in our field test for 14 years. Trials of similar formulations on simulated decking are also reported to provide additional information on the ability of boron and fluoride to protect exposed Douglas-fir heartwood. Efforts to improve the effectiveness of through boring as a method for enhancing the treatment of Douglas-fir poles are continuing. This past year, we evaluated preservative distribution around through bored holes as a means of developing optimum through boring patterns that maximized treatment while minimizing potential strength effects. These trials suggest the diamond shaped through boring zone of effect is relatively narrow. This information will be used in the coming year to construct optimum patterns for poles of various classes. The goal of this project is to develop a standard through boring pattern that would permit automation of the process. This would create the potential for cost savings on new poles. Trials to evaluate the durability of western redcedar are nearly complete. These trials were initiated because of concerns that second growth western redcedar might be less durable than poles cut from older trees. As expected, cedar varied widely in its resistance to fungal attack. This resistance, however, was not related to tree age, suggesting that there might not be a difference between so-called "old-growth" and "second growth" material. These data will be more thoroughly analyzed once the final set of trials are completed. In addition, we are evaluating more rapid methods for assessing cedar durability by measuring tropolone content. Tropolones are an important component of the extractives that make cedar heartwood so durable. Field trials of various externally applied supplemental groundline treatments are continuing at sites in Oregon, California, and New York. Trials in Corvallis, Oregon, have shown that various copper naphthenate, fluoride or boron based systems are at least as effective as the pentachlorophenol (penta) based systems that were formerly used for this purpose. Penta concentrations in one system have now declined below a protective level, while the copper based systems continue to remain at a protective level. Field trials in California are following similar trends and indicate that the alternative systems will provide comparable performance. Fungus cellar trials of copper naphthenate treated western redcedar stakes continue to show that this chemical provides excellent protection to cedar sapwood. Weathered wood that was treated with copper naphthenate continues to perform more poorly than freshly sawn wood treated to similar retention levels. Variations in permeability likely account for these differences. A new Wood Pole Maintenance Manual has been completed and is now ready for distribution. This update of the 1979 publication includes more information on initial pole procurement and closely follows the video by the same name that we produced in 1994. Close