Search

Search Results

• 201. [Article] Nesting and foraging ecology of band-tailed pigeons in western Oregon

  Pacific Coast band-tailed pigeons (Columba fasciata) have declined markedly during the past several decades. Despite implementation of increasingly restrictive hunting regulations, populations have shown ...

  Citation × Citation Citation Abstract Copy Title: Nesting and foraging ecology of band-tailed pigeons in western Oregon Author: Leonard, Jerome Patrick Pacific Coast band-tailed pigeons (Columba fasciata) have declined markedly during the past several decades. Despite implementation of increasingly restrictive hunting regulations, populations have shown minimal signs of recovery. I radio-marked 127 adult band-tailed pigeons in the central Oregon Coast Range in April-May of 1993-95 to document nesting chronology and productivity, and characterize nesting and feeding habitats. One-hundred and thirty-seven nests initiated by 65 different birds were monitored. Multiple brooding was predominant; 45 birds initiated 2-3 nests each with 7 birds producing 3 successful nests each in one nesting season. All nests had a clutch size of 1. The reproductive period started in late-April and went through mid- to late-October. Nesting attempts peaked mid- to late-June, and 21% of all young fledged after September 15. Nest re-use was rare, but 78% of the consecutive nests I observed by individual birds eliminated nesting intervals by overlapping nesting cycles. Nesting overlap averaged 7 days. Nest survival probabilities were consistent between years with a pooled estimate of 0.689 (95% C.I = 0.613-0.775). Band-tails nested in a variety of tree and shrub species, with 70% of the nests observed in Douglas-fir (Pseudotsuga menzesii). Only 17% of all nests were in deciduous trees or shrubs. Nest height was highly variable and averaged 10.3 m. They also used a variety of stand conditions (open and closed) and seral/community types (sapling-pole to old-growth in deciduous and conifer communities). However, the majority of nests (77%) were in stands classified as conifer community with 55% in the closed-canopy, sapling-pole seral condition. Feed areas were diverse in their physical and vegetative characteristics and were located in both riparian and upland zones. The principal food component within most of these sites was either Pacific red elder (Sambucas racemosa) or cascara buckthorn (Rhamnus purshianus). Band-tailed pigeons were highly mobile throughout their nesting season. They traveled an average of 5.02 km to feed areas and had a mean home range size of 11,121 ha. Due to their mobility, and diverse habitat use, band-tailed pigeons would be an important species for consideration in large watershed management designs. Title: Nesting and foraging ecology of band-tailed pigeons in western Oregon Author: Leonard, Jerome Patrick Pacific Coast band-tailed pigeons (Columba fasciata) have declined markedly during the past several decades. Despite implementation of increasingly restrictive hunting regulations, populations have shown minimal signs of recovery. I radio-marked 127 adult band-tailed pigeons in the central Oregon Coast Range in April-May of 1993-95 to document nesting chronology and productivity, and characterize nesting and feeding habitats. One-hundred and thirty-seven nests initiated by 65 different birds were monitored. Multiple brooding was predominant; 45 birds initiated 2-3 nests each with 7 birds producing 3 successful nests each in one nesting season. All nests had a clutch size of 1. The reproductive period started in late-April and went through mid- to late-October. Nesting attempts peaked mid- to late-June, and 21% of all young fledged after September 15. Nest re-use was rare, but 78% of the consecutive nests I observed by individual birds eliminated nesting intervals by overlapping nesting cycles. Nesting overlap averaged 7 days. Nest survival probabilities were consistent between years with a pooled estimate of 0.689 (95% C.I = 0.613-0.775). Band-tails nested in a variety of tree and shrub species, with 70% of the nests observed in Douglas-fir (Pseudotsuga menzesii). Only 17% of all nests were in deciduous trees or shrubs. Nest height was highly variable and averaged 10.3 m. They also used a variety of stand conditions (open and closed) and seral/community types (sapling-pole to old-growth in deciduous and conifer communities). However, the majority of nests (77%) were in stands classified as conifer community with 55% in the closed-canopy, sapling-pole seral condition. Feed areas were diverse in their physical and vegetative characteristics and were located in both riparian and upland zones. The principal food component within most of these sites was either Pacific red elder (Sambucas racemosa) or cascara buckthorn (Rhamnus purshianus). Band-tailed pigeons were highly mobile throughout their nesting season. They traveled an average of 5.02 km to feed areas and had a mean home range size of 11,121 ha. Due to their mobility, and diverse habitat use, band-tailed pigeons would be an important species for consideration in large watershed management designs. Close

• 202. [Article] Mapping conservation opportunity areas for the Intertwine's Regional Conservation Strategy

  Draft report from the Institute for Natural Resources, Portland State University

  Citation × Citation Citation Abstract Copy Title: Mapping conservation opportunity areas for the Intertwine's Regional Conservation Strategy Author: Kagan, James S., Burcsu, Theresa Draft report from the Institute for Natural Resources, Portland State University Title: Mapping conservation opportunity areas for the Intertwine's Regional Conservation Strategy Author: Kagan, James S., Burcsu, Theresa Draft report from the Institute for Natural Resources, Portland State University Close

• 203. [Article] Summertime stream temperatures in the North and South Forks of the Sprague River, south central Oregon

  The Upper Sprague River Watershed (North and South Forks of the Sprague River) in south central Oregon provides important habitat for salmonid species, including native bull trout (Salvelinus confluentus) ...

  Citation × Citation Citation Abstract Copy Title: Summertime stream temperatures in the North and South Forks of the Sprague River, south central Oregon Author: Friedrichsen, Paul T. The Upper Sprague River Watershed (North and South Forks of the Sprague River) in south central Oregon provides important habitat for salmonid species, including native bull trout (Salvelinus confluentus) and redband trout (Oncorhynchus mykiss ssp.). Concern over the loss of viable habitat for these species has increased due to reductions in channel and habitat complexity, and modification of riparian vegetation. Many of the factors affecting habitat quality also influence water temperature, which is an important habitat component of salmonids during the summer months. Maximum stream temperatures and diel fluctuations in the Upper Sprague River System generally reflected local reach characteristics, position in the drainage, and large scale changes in valley shape. Stream temperatures in the North Fork Sprague River (NFSR), at a distance of 35 km from the drainage divide, equalled or exceeded 15°C, the 'upper preferred temperature' for salmonids, 16% and 36% of the time during the seven-consecutive warmest days of 1993 and 1994, respectively. Upstream of Lee Thomas Meadow (LTM), 6.5 km from the drainage divide, 15°C was equalled or exceeded only 1% and 13% of the time during the same period, while below LTM (18.3 km from the drainage divide), 15°C was exceeded 66% and 85% of the time during this sante period. Diel fluctuations in the NFSR were greatest immediately below LTM (>11.8°C), decreasing to <6.0°C below the canyon section at the mouth of the watershed during both 1993 and 1994. In the South Fork Sprague River (SFSR), 15°C was equalled or exceeded 79% and 99% of the time during the seven-consecutive warmest days of 1993 and 1994, respectively, 28.4 km from the divide. At this same distance, the upper lethal limit of 25°C was equalled or exceeded 16% of the time in 1994, representing very stressful or potentially life-threatening conditions for salmonids. Diel fluctuations for the SFSR were >6.5°C both years, the highest values being 9.5°C or greater at 28.4 kin from the divide. Seven-day maximum stream temperatures and diel fluctuations in tributaries of the Upper Sprague River System varied widely during the study period. Maximum stream temperatures varied from 13.8°C to 23.1°C while diel fluctuations varied from 4.8°C to 11.0°C; the highest values corresponding with relatively open, unshaded reaches and the lower values corresponding with shaded, forested reaches. Relationships between stream temperatures, stream cover and channel morphology characteristics were evaluated for eight reaches within the study area. Only stream cover was found to be significantly (p <0.05) related to seven-day maximum stream temperatures, change in stream temperatures, and diurnal fluctuations in stream temperatures based on simple linear regression. When multiple linear regression analysis was used, several combinations of independent variables were found to be significantly (p <0.05) related to seven-day maximum stream temperatures, and/or change in stream temperatures, and/or diurnal fluctuations in stream temperatures. The variables that were consistently part of significant (p <0.05) regressions included: stream cover, wetted width, thalweg depth, width/depth ratio, and reach length. A stream temperature model, SHADOW, was found to be a relatively good predictor of maximum stream temperatures for short (1130 m) reaches and generally a poor predictor for longer (1340-4130 m) reaches. For the three short reaches (1130 m), the average difference between observed and modelled temperatures was 0°C (±0.3°C); for the five longer reaches (1340-4130 m), the average difference was 2.9°C (±0.6°C) indicating that the SHADOW Model over-predicted stream temperatures for these longer reaches. The shortest forested reach was under-predicted by 0.4°C. Temperature simulations for five meadow reaches using SHADOW and multiple regression models suggest that lower maximum stream temperatures would be observed if stream cover were increased. Title: Summertime stream temperatures in the North and South Forks of the Sprague River, south central Oregon Author: Friedrichsen, Paul T. The Upper Sprague River Watershed (North and South Forks of the Sprague River) in south central Oregon provides important habitat for salmonid species, including native bull trout (Salvelinus confluentus) and redband trout (Oncorhynchus mykiss ssp.). Concern over the loss of viable habitat for these species has increased due to reductions in channel and habitat complexity, and modification of riparian vegetation. Many of the factors affecting habitat quality also influence water temperature, which is an important habitat component of salmonids during the summer months. Maximum stream temperatures and diel fluctuations in the Upper Sprague River System generally reflected local reach characteristics, position in the drainage, and large scale changes in valley shape. Stream temperatures in the North Fork Sprague River (NFSR), at a distance of 35 km from the drainage divide, equalled or exceeded 15°C, the 'upper preferred temperature' for salmonids, 16% and 36% of the time during the seven-consecutive warmest days of 1993 and 1994, respectively. Upstream of Lee Thomas Meadow (LTM), 6.5 km from the drainage divide, 15°C was equalled or exceeded only 1% and 13% of the time during the same period, while below LTM (18.3 km from the drainage divide), 15°C was exceeded 66% and 85% of the time during this sante period. Diel fluctuations in the NFSR were greatest immediately below LTM (>11.8°C), decreasing to <6.0°C below the canyon section at the mouth of the watershed during both 1993 and 1994. In the South Fork Sprague River (SFSR), 15°C was equalled or exceeded 79% and 99% of the time during the seven-consecutive warmest days of 1993 and 1994, respectively, 28.4 km from the divide. At this same distance, the upper lethal limit of 25°C was equalled or exceeded 16% of the time in 1994, representing very stressful or potentially life-threatening conditions for salmonids. Diel fluctuations for the SFSR were >6.5°C both years, the highest values being 9.5°C or greater at 28.4 kin from the divide. Seven-day maximum stream temperatures and diel fluctuations in tributaries of the Upper Sprague River System varied widely during the study period. Maximum stream temperatures varied from 13.8°C to 23.1°C while diel fluctuations varied from 4.8°C to 11.0°C; the highest values corresponding with relatively open, unshaded reaches and the lower values corresponding with shaded, forested reaches. Relationships between stream temperatures, stream cover and channel morphology characteristics were evaluated for eight reaches within the study area. Only stream cover was found to be significantly (p <0.05) related to seven-day maximum stream temperatures, change in stream temperatures, and diurnal fluctuations in stream temperatures based on simple linear regression. When multiple linear regression analysis was used, several combinations of independent variables were found to be significantly (p <0.05) related to seven-day maximum stream temperatures, and/or change in stream temperatures, and/or diurnal fluctuations in stream temperatures. The variables that were consistently part of significant (p <0.05) regressions included: stream cover, wetted width, thalweg depth, width/depth ratio, and reach length. A stream temperature model, SHADOW, was found to be a relatively good predictor of maximum stream temperatures for short (1130 m) reaches and generally a poor predictor for longer (1340-4130 m) reaches. For the three short reaches (1130 m), the average difference between observed and modelled temperatures was 0°C (±0.3°C); for the five longer reaches (1340-4130 m), the average difference was 2.9°C (±0.6°C) indicating that the SHADOW Model over-predicted stream temperatures for these longer reaches. The shortest forested reach was under-predicted by 0.4°C. Temperature simulations for five meadow reaches using SHADOW and multiple regression models suggest that lower maximum stream temperatures would be observed if stream cover were increased. Close

• 204. [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

• 205. [Article] Influences of clearcut logging on macroinvertebrates in perennial and intermittent headwaters of the Central Oregon Coast Range

  This research was designed to broaden the understanding of how timber-harvest affects aquatic macroinvertebrates in perennial and intermittent headwater streams. This study compared emergent and benthic ...

  Citation × Citation Citation Abstract Copy Title: Influences of clearcut logging on macroinvertebrates in perennial and intermittent headwaters of the Central Oregon Coast Range Author: Banks, Janel This research was designed to broaden the understanding of how timber-harvest affects aquatic macroinvertebrates in perennial and intermittent headwater streams. This study compared emergent and benthic macroinvertebrate assemblages from 20 headwater streams in the central Oregon Coast Range that varied by harvest condition and flow duration. Through comparison of the community and functional characteristics of the macroinvertebrates in similar streams under different harvest conditions, logging impacts on adult and immature aquatic macroinvertebrates in perennial and intermittent streams were assessed. Adult insects emerging from the 20 study streams were collected using emergence traps set for four weeks in a 40-meter reach during three sampling periods: August-September 2003, October-November 2003, and April-May 2004. Adult aquatic insects were identified to genus and family taxonomic levels and results were expressed as number of individuals emerging per m2 per day. Benthic samples were taken from each reach in May 2004, insects and non-insects were identified to various taxonomic levels, and results were expressed as number of individuals per m2. Ten streams were located in catchments that were clearcut to the stream bank no more than a year before sampling began; three of these streams were intermittent and seven were perennial. Intermittent streams were summer-dry and retained surface-water for a minimum of eight months during the year, while perennial streams had surface flow year-round. The other ten streams (four intermittent and six perennial) were located in forested catchments that have not been logged for at least 34 years. The physical habitat of each stream reach was assessed in August 2003. Regardless of flow-duration or season, more aquatic insects emerged from streams in logged catchments. The emergence rate of Diptera, predominantly Chironomidae, was especially high from clearcut sites. More Trichoptera also emerged from clearcut sites. Ephemeroptera and Plecoptera did not emerge at rates that varied by logging condition. Plecoptera had higher emergence from intermittent than perennial sites in spring. Taxa richness was higher at clearcut sites, driven primarily by rare taxa encountered in less than 5 of the 10 clearcut sites. Emergent insect functional feeding group composition was affected by harvest condition with collector-filterers emerging at higher rates from clearcut sites. Examination of community patterns through nonmetric multidimensional scaling (NMS) ordination analyses indicated that emergent aquatic macroinvertebrate assemblages differ by season and by harvest condition. The duration of stream flow did not strongly influence adult assemblages. Channel dimensions (active channel and bankfull width) and catchment area were correlated with ordination-axes, but were not different between logged and forested sites. The amount of riparian cover (canopy, understory, and groundcover), stand age, slash, and stream cover were all considerably different between logged and forested sites and were highly influential on emergent assemblages. Substrate size was also influential on adult assemblages. Mean water temperature in summer, fall, and spring was highly correlated with seasonal variation in assemblages. Regardless of harvest-condition, intermittent streams had higher overall benthic macroinvertebrate density. Trichoptera had higher densities at intermittent sites than perennial sites, while Diptera, Plecoptera, and non-insects had similar densities between categories of flow duration and harvest condition. Benthic macroinvertebrate functional composition was also affected by flow-duration, with collector-filterers, collector-gatherers, and predators occurring at higher densities at intermittent sites than perennial sites. The densities of scrapers and shredders did not differ between classes of flow duration or harvest condition. The majority of taxa (72%) were common to both perennial and intermittent sites; however, taxa richness was lower at intermittent sites. NMS-ordination analyses of the benthic macroinvertebrates showed that community patterns differed by harvest condition within the perennial flow-duration class. Benthic communities of intermittent streams did not differ between harvest conditions. Channel dimensions (active channel and bankfull width), mean substrate diameter, percent stream-cover, mean water temperature, elevation, and percent small riparian trees influenced benthic community assemblages. The majority of perennial-clearcut sites had macroinvertebrate community patterns more similar to intermittent-forested and intermittent-clearcut streams than to perennial-forested sites. The two perennial-clearcut sites that did not have benthic assemblages similar to the other five perennial-clearcut sites had larger diameter substrate, higher elevation, larger catchment area, and cooler mean water temperature than other perennial-clearcut sites. This study provides evidence that Oregon’s current timber harvesting practices impact macroinvertebrate assemblages of perennial and intermittent headwaters in the Central Oregon Coast Range within a year following harvest. When the studied streams were clearcut to the streambank, there was increased emergence of adult macroinvertebrates, principally midges, at clearcut sites. Benthic assemblages differed primarily between intermittent and perennial flow-duration. However, within flow-classes, assemblages of benthic aquatic macroinvertebrates in perennial streams were impacted by clearcut logging to a higher degree than intermittent streams. Perennial-clearcut streams had different benthic assemblages from perennial-mature streams and perennial-clearcut streams with coarser substrate and cooler temperatures. Intermittent streams, which generally experience fewer flushing events and accumulate finer substrates than perennial streams, may be affected to a lesser degree by any sedimentation caused by logging activity. Correlations of emergent and benthic macroinvertebrate communities with the measured environmental gradients are suggestive that reduced canopy cover and substrate composition are major influential factors. Title: Influences of clearcut logging on macroinvertebrates in perennial and intermittent headwaters of the Central Oregon Coast Range Author: Banks, Janel This research was designed to broaden the understanding of how timber-harvest affects aquatic macroinvertebrates in perennial and intermittent headwater streams. This study compared emergent and benthic macroinvertebrate assemblages from 20 headwater streams in the central Oregon Coast Range that varied by harvest condition and flow duration. Through comparison of the community and functional characteristics of the macroinvertebrates in similar streams under different harvest conditions, logging impacts on adult and immature aquatic macroinvertebrates in perennial and intermittent streams were assessed. Adult insects emerging from the 20 study streams were collected using emergence traps set for four weeks in a 40-meter reach during three sampling periods: August-September 2003, October-November 2003, and April-May 2004. Adult aquatic insects were identified to genus and family taxonomic levels and results were expressed as number of individuals emerging per m2 per day. Benthic samples were taken from each reach in May 2004, insects and non-insects were identified to various taxonomic levels, and results were expressed as number of individuals per m2. Ten streams were located in catchments that were clearcut to the stream bank no more than a year before sampling began; three of these streams were intermittent and seven were perennial. Intermittent streams were summer-dry and retained surface-water for a minimum of eight months during the year, while perennial streams had surface flow year-round. The other ten streams (four intermittent and six perennial) were located in forested catchments that have not been logged for at least 34 years. The physical habitat of each stream reach was assessed in August 2003. Regardless of flow-duration or season, more aquatic insects emerged from streams in logged catchments. The emergence rate of Diptera, predominantly Chironomidae, was especially high from clearcut sites. More Trichoptera also emerged from clearcut sites. Ephemeroptera and Plecoptera did not emerge at rates that varied by logging condition. Plecoptera had higher emergence from intermittent than perennial sites in spring. Taxa richness was higher at clearcut sites, driven primarily by rare taxa encountered in less than 5 of the 10 clearcut sites. Emergent insect functional feeding group composition was affected by harvest condition with collector-filterers emerging at higher rates from clearcut sites. Examination of community patterns through nonmetric multidimensional scaling (NMS) ordination analyses indicated that emergent aquatic macroinvertebrate assemblages differ by season and by harvest condition. The duration of stream flow did not strongly influence adult assemblages. Channel dimensions (active channel and bankfull width) and catchment area were correlated with ordination-axes, but were not different between logged and forested sites. The amount of riparian cover (canopy, understory, and groundcover), stand age, slash, and stream cover were all considerably different between logged and forested sites and were highly influential on emergent assemblages. Substrate size was also influential on adult assemblages. Mean water temperature in summer, fall, and spring was highly correlated with seasonal variation in assemblages. Regardless of harvest-condition, intermittent streams had higher overall benthic macroinvertebrate density. Trichoptera had higher densities at intermittent sites than perennial sites, while Diptera, Plecoptera, and non-insects had similar densities between categories of flow duration and harvest condition. Benthic macroinvertebrate functional composition was also affected by flow-duration, with collector-filterers, collector-gatherers, and predators occurring at higher densities at intermittent sites than perennial sites. The densities of scrapers and shredders did not differ between classes of flow duration or harvest condition. The majority of taxa (72%) were common to both perennial and intermittent sites; however, taxa richness was lower at intermittent sites. NMS-ordination analyses of the benthic macroinvertebrates showed that community patterns differed by harvest condition within the perennial flow-duration class. Benthic communities of intermittent streams did not differ between harvest conditions. Channel dimensions (active channel and bankfull width), mean substrate diameter, percent stream-cover, mean water temperature, elevation, and percent small riparian trees influenced benthic community assemblages. The majority of perennial-clearcut sites had macroinvertebrate community patterns more similar to intermittent-forested and intermittent-clearcut streams than to perennial-forested sites. The two perennial-clearcut sites that did not have benthic assemblages similar to the other five perennial-clearcut sites had larger diameter substrate, higher elevation, larger catchment area, and cooler mean water temperature than other perennial-clearcut sites. This study provides evidence that Oregon’s current timber harvesting practices impact macroinvertebrate assemblages of perennial and intermittent headwaters in the Central Oregon Coast Range within a year following harvest. When the studied streams were clearcut to the streambank, there was increased emergence of adult macroinvertebrates, principally midges, at clearcut sites. Benthic assemblages differed primarily between intermittent and perennial flow-duration. However, within flow-classes, assemblages of benthic aquatic macroinvertebrates in perennial streams were impacted by clearcut logging to a higher degree than intermittent streams. Perennial-clearcut streams had different benthic assemblages from perennial-mature streams and perennial-clearcut streams with coarser substrate and cooler temperatures. Intermittent streams, which generally experience fewer flushing events and accumulate finer substrates than perennial streams, may be affected to a lesser degree by any sedimentation caused by logging activity. Correlations of emergent and benthic macroinvertebrate communities with the measured environmental gradients are suggestive that reduced canopy cover and substrate composition are major influential factors. Close

• 206. [Article] Early competitive interactions between red alder and salmonberry in the Oregon Coast Range

  General outcomes of this study show that early growth of planted red alder is often slowed in the presence of neighboring vegetation, and overwhelmingly by salmonberry, a common associate in disturbed ...

  Citation × Citation Citation Abstract Copy Title: Early competitive interactions between red alder and salmonberry in the Oregon Coast Range Author: Kelly, Linda Susan General outcomes of this study show that early growth of planted red alder is often slowed in the presence of neighboring vegetation, and overwhelmingly by salmonberry, a common associate in disturbed Oregon Coast Range habitats. Additionally, young red alder plantations located in riparian areas may be highly susceptible to frost injury or death and animal damage, particularly by beavers and mountain beavers. Growth analysis of two- and three-year old red alder planted at seventeen planting densities in a type 1a Nelder design are represented in this study. Each density is also analyzed in the presence and absence of salmonberry-dominated "weedy" vegetation native to the Oregon Coast Range. Red alder volume growth was reduced with increasing density of planted seedlings when salmonberry was not present, but intraspecific competition was eliminated in the presence of salmonberry. Red alder seedlings grew less in volume with salmonberry competition than at the highest weed-free planting densities. Although salmonberry presence played a significantly larger role in decreasing early growth of young alder than intraspecific competition among experimentally-induced planting densities, competition between individual red alder seedlings began at plantation age two, where alders were weed free and grew large enough to compete with other alders. Indications show that density competition between trees will increase as the stand develops. Drought stress did not significantly affect young red alder growth on these generally mesic sites. Among growth parameters, diameter and volume increment and height:diameter ratios were the most sensitive indicators of planting density and shrub and herbaceous competition among young red alders. Therefore, these measurements may be used to best predict early competitive stress in tree seedlings. Conversely, early height growth was too variable to be of significant predictive value for density and salmonberry competition effects. Study results imply that the successful establishment of red alder in Oregon Coast Range habitats may benefit from proper spacing of planted seedlings and minimizing the potential for salmonberry invasion, animal browsing and frost injury to trees in the initial years of stand development. Title: Early competitive interactions between red alder and salmonberry in the Oregon Coast Range Author: Kelly, Linda Susan General outcomes of this study show that early growth of planted red alder is often slowed in the presence of neighboring vegetation, and overwhelmingly by salmonberry, a common associate in disturbed Oregon Coast Range habitats. Additionally, young red alder plantations located in riparian areas may be highly susceptible to frost injury or death and animal damage, particularly by beavers and mountain beavers. Growth analysis of two- and three-year old red alder planted at seventeen planting densities in a type 1a Nelder design are represented in this study. Each density is also analyzed in the presence and absence of salmonberry-dominated "weedy" vegetation native to the Oregon Coast Range. Red alder volume growth was reduced with increasing density of planted seedlings when salmonberry was not present, but intraspecific competition was eliminated in the presence of salmonberry. Red alder seedlings grew less in volume with salmonberry competition than at the highest weed-free planting densities. Although salmonberry presence played a significantly larger role in decreasing early growth of young alder than intraspecific competition among experimentally-induced planting densities, competition between individual red alder seedlings began at plantation age two, where alders were weed free and grew large enough to compete with other alders. Indications show that density competition between trees will increase as the stand develops. Drought stress did not significantly affect young red alder growth on these generally mesic sites. Among growth parameters, diameter and volume increment and height:diameter ratios were the most sensitive indicators of planting density and shrub and herbaceous competition among young red alders. Therefore, these measurements may be used to best predict early competitive stress in tree seedlings. Conversely, early height growth was too variable to be of significant predictive value for density and salmonberry competition effects. Study results imply that the successful establishment of red alder in Oregon Coast Range habitats may benefit from proper spacing of planted seedlings and minimizing the potential for salmonberry invasion, animal browsing and frost injury to trees in the initial years of stand development. Close

• 207. [Article] A Collaborative Effort to Evaluate Water Resources in the Lower Siuslaw Watershed

  Presented at The Oregon Water Conference, May 24-25, 2011, Corvallis, OR.

  Citation × Citation Citation Abstract Copy Title: A Collaborative Effort to Evaluate Water Resources in the Lower Siuslaw Watershed Author: Livesay, Dave, Miller, Mike, Nelson, Dennis, Moellendorf, Suzanne Year: 2011 Presented at The Oregon Water Conference, May 24-25, 2011, Corvallis, OR. Title: A Collaborative Effort to Evaluate Water Resources in the Lower Siuslaw Watershed Author: Livesay, Dave, Miller, Mike, Nelson, Dennis, Moellendorf, Suzanne Year: 2011 Presented at The Oregon Water Conference, May 24-25, 2011, Corvallis, OR. Close

• 208. [Article] Competitive Interactions and Resource Partitioning Between Northern Spotted Owls and Barred Owls in Western Oregon

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Wildlife Society ...

  Citation × Citation Citation Abstract Copy Title: Competitive Interactions and Resource Partitioning Between Northern Spotted Owls and Barred Owls in Western Oregon Author: Forsman, Eric D., Anthony, Robert G., Wiens, J. David To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Wildlife Society and published by John Wiley & Sons, Ltd. It can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291938-5455. Title: Competitive Interactions and Resource Partitioning Between Northern Spotted Owls and Barred Owls in Western Oregon Author: Forsman, Eric D., Anthony, Robert G., Wiens, J. David To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Wildlife Society and published by John Wiley & Sons, Ltd. It can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291938-5455. Close

• 209. [Article] A study of in stream complexity in three Oregon Coast Range watersheds

  This study investigates patterns of physical structure organization in stream networks. In particular, it seeks to describe patterns of wood, boulders, pools and slope that are evident in stream channels ...

  Citation × Citation Citation Abstract Copy Title: A study of in stream complexity in three Oregon Coast Range watersheds Author: Anderson, Paul Khalil This study investigates patterns of physical structure organization in stream networks. In particular, it seeks to describe patterns of wood, boulders, pools and slope that are evident in stream channels and to determine whether patterns of these elements are influenced by network-level controls. The four in-stream parameters were combined to produce a metric of complexity, which was used to investigate differences in patters and organization of in-stream structure within and between watersheds. Research was conducted in three Oregon Coast Range watersheds' Rogers Creek in the Northern Oregon Coast Range, and Turner and Elk Creeks in the South Central Oregon Coast Range. Rogers, Turner and Elk Creeks were 26km2, 12km2, and 17km2 respectively and fell into two distinct geologic regions, basalt geology in the north and sandstone geology in the south. Fifteen km of stream were surveyed in 60 meter segments for a total of 246 stream segments observations. There were 77, 70, and 99 study segments in Rogers, Turner and Elk Creeks respectively. The network-level controls investigated were stream junctions, channel constraint, and debris flows. It was hypothesized that these network-level controls influence in-stream complexity by encouraging uneven distribution of large material which in turn influences stream slope and pooi abundance. Network-level controls where associated with differing patterns of complexity in each watershed. The influence of the network-level control was in part dependent on factors including: geologic setting, stream slope differences and difference in disturbance regimes. Stream junctions and constrained segments were found to be associated with some of the highest values of complexity, while recent debris flows were associated with lower complexity values. Several of the hypotheses described in the Network Dynamics Hypothesis (Benda et al. 2004b) were investigated using a geographic information system (GIS) and data derived from a digital elevation model (DEM). The GIS was used to test for relationships between field measured complexity and stream network parameters that were developed using a program for DEM analysis. DEM derived data for the contributing area, junction angle and debris flow potential at sample points illustrated a weak relationship with complexity. By better understanding the influence of network level controls on complexity it may be possible to improve the understanding of how stream networks connect hillslope and riparian environments, thereby aiding watershed management and identifying locations of diverse habitat in the stream network. Title: A study of in stream complexity in three Oregon Coast Range watersheds Author: Anderson, Paul Khalil This study investigates patterns of physical structure organization in stream networks. In particular, it seeks to describe patterns of wood, boulders, pools and slope that are evident in stream channels and to determine whether patterns of these elements are influenced by network-level controls. The four in-stream parameters were combined to produce a metric of complexity, which was used to investigate differences in patters and organization of in-stream structure within and between watersheds. Research was conducted in three Oregon Coast Range watersheds' Rogers Creek in the Northern Oregon Coast Range, and Turner and Elk Creeks in the South Central Oregon Coast Range. Rogers, Turner and Elk Creeks were 26km2, 12km2, and 17km2 respectively and fell into two distinct geologic regions, basalt geology in the north and sandstone geology in the south. Fifteen km of stream were surveyed in 60 meter segments for a total of 246 stream segments observations. There were 77, 70, and 99 study segments in Rogers, Turner and Elk Creeks respectively. The network-level controls investigated were stream junctions, channel constraint, and debris flows. It was hypothesized that these network-level controls influence in-stream complexity by encouraging uneven distribution of large material which in turn influences stream slope and pooi abundance. Network-level controls where associated with differing patterns of complexity in each watershed. The influence of the network-level control was in part dependent on factors including: geologic setting, stream slope differences and difference in disturbance regimes. Stream junctions and constrained segments were found to be associated with some of the highest values of complexity, while recent debris flows were associated with lower complexity values. Several of the hypotheses described in the Network Dynamics Hypothesis (Benda et al. 2004b) were investigated using a geographic information system (GIS) and data derived from a digital elevation model (DEM). The GIS was used to test for relationships between field measured complexity and stream network parameters that were developed using a program for DEM analysis. DEM derived data for the contributing area, junction angle and debris flow potential at sample points illustrated a weak relationship with complexity. By better understanding the influence of network level controls on complexity it may be possible to improve the understanding of how stream networks connect hillslope and riparian environments, thereby aiding watershed management and identifying locations of diverse habitat in the stream network. Close

• 210. [Article] Debris flow characteristics associated with forest practices in the central Oregon Coast Range

  Debris flows in the Pacific Northwest play a major role in routing wood and sediment stored on hillslopes and in first- through third-order channels to higher order channels and valley floors. Forest practices ...

  Citation × Citation Citation Abstract Copy Title: Debris flow characteristics associated with forest practices in the central Oregon Coast Range Author: May, Christine L. Debris flows in the Pacific Northwest play a major role in routing wood and sediment stored on hillslopes and in first- through third-order channels to higher order channels and valley floors. Forest practices on steep, unstable slopes and removal of riparian trees along low-order streams can affect the frequency, magnitude, and composition of debris flows. The quantity and quality of debris flow deposits provides sediment and wood fundamental to the development of the receiving channel. Field surveys document characteristics of the initiation site, runout zone, and deposit of 53 debris flows in the Siuslaw Basin of the central Oregon Coast Range, during the winter of 1996. Landslides that initiated debris flows in clearcuts had a higher frequency, larger average volume, and runout zones that affected a greater length of stream channel than landslides from forested slopes. This difference resulted in an increase in the total volume of sediment mobilized by the debris flow, and a greater proportion of this sediment came from hillslope sources. Debris flows initiated at roads had an order of magnitude greater volume of sediment compared to non-road-related failures. Debris flows of equivalent size that traveled through a forested channel delivered only a slightly greater volume of large wood, than those through clearcuts. Size-class distributions of wood in the deposit and trees on the hillslope were not well correlated. The average diameter of wood in the deposit was greater than the diameter of trees currently present on the surrounding hillslopes. This difference reflects the legacy of large woody debris stored in low-order channels and valley floors. Large trees along the edge of the runout zone is also an important component in the recovery of these low-order channels, which were transformed into a bedrock state. Large trees along the edges of forested slopes are already supplying wood to these channels, and were the only mechanism observed for trapping large volumes of sediment. This mechanism for retaining sediment in high gradient, low-roughness channels is not available in clearcuts, which now contain the greatest proportion of bedrock channels. Forest practices, by altering the frequency, magnitude, and composition of the debris flow, may alter the long-term potential for developing complex channel morphology and high-quality aquatic habitat. Title: Debris flow characteristics associated with forest practices in the central Oregon Coast Range Author: May, Christine L. Debris flows in the Pacific Northwest play a major role in routing wood and sediment stored on hillslopes and in first- through third-order channels to higher order channels and valley floors. Forest practices on steep, unstable slopes and removal of riparian trees along low-order streams can affect the frequency, magnitude, and composition of debris flows. The quantity and quality of debris flow deposits provides sediment and wood fundamental to the development of the receiving channel. Field surveys document characteristics of the initiation site, runout zone, and deposit of 53 debris flows in the Siuslaw Basin of the central Oregon Coast Range, during the winter of 1996. Landslides that initiated debris flows in clearcuts had a higher frequency, larger average volume, and runout zones that affected a greater length of stream channel than landslides from forested slopes. This difference resulted in an increase in the total volume of sediment mobilized by the debris flow, and a greater proportion of this sediment came from hillslope sources. Debris flows initiated at roads had an order of magnitude greater volume of sediment compared to non-road-related failures. Debris flows of equivalent size that traveled through a forested channel delivered only a slightly greater volume of large wood, than those through clearcuts. Size-class distributions of wood in the deposit and trees on the hillslope were not well correlated. The average diameter of wood in the deposit was greater than the diameter of trees currently present on the surrounding hillslopes. This difference reflects the legacy of large woody debris stored in low-order channels and valley floors. Large trees along the edge of the runout zone is also an important component in the recovery of these low-order channels, which were transformed into a bedrock state. Large trees along the edges of forested slopes are already supplying wood to these channels, and were the only mechanism observed for trapping large volumes of sediment. This mechanism for retaining sediment in high gradient, low-roughness channels is not available in clearcuts, which now contain the greatest proportion of bedrock channels. Forest practices, by altering the frequency, magnitude, and composition of the debris flow, may alter the long-term potential for developing complex channel morphology and high-quality aquatic habitat. Close