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• 21. [Article] Klamath River Canyon vegetation and road treatments environmental assessment and finding of no significant impact

  43 pp. Tables, appendices, maps, references, illus. The project analysis area is located within and adjacent to the Klamath River Canyon in southern Oregon (see map 1). Captured July 2, 2008.

  Citation × Citation Citation Abstract Copy Title: Klamath River Canyon vegetation and road treatments environmental assessment and finding of no significant impact Author: United States. Bureau of Land Management. Lakeview District Year: 2008 43 pp. Tables, appendices, maps, references, illus. The project analysis area is located within and adjacent to the Klamath River Canyon in southern Oregon (see map 1). Captured July 2, 2008. Title: Klamath River Canyon vegetation and road treatments environmental assessment and finding of no significant impact Author: United States. Bureau of Land Management. Lakeview District Year: 2008 43 pp. Tables, appendices, maps, references, illus. The project analysis area is located within and adjacent to the Klamath River Canyon in southern Oregon (see map 1). Captured July 2, 2008. Close

• 22. [Article] Oregon Natural Areas Plan

  The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, ...

  Citation × Citation Citation Abstract Copy Title: Oregon Natural Areas Plan Author: Oregon Natural Heritage Advisory Council Year: 2010 The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, deserts, marshes, estuaries, dunes, rocky headlands, lakes and streams. There are a number of reasons it is so diverse. First are the extremes of climate, with rainfall ranging from over 200 inches a year along Oregon’s north coast, to less than 7 inches a year in the Alvord Desert, and temperatures from the very mild banana belt along the coast near the California border to the extremes of the high alpine areas of the Wallowa Mountains. Secondly, Oregon is diverse geographically and geologically, having ancient serpentine landscapes in the Siskiyou Mountains and recent volcanics in the Cascades and the deepest gorge in North America at Hells Canyon. Lastly, Oregon is a floristic crossroads, with arctic boreal species finding their southern limit, Rocky Mountain species common in northeastern Oregon, Great Basin species in southeastern Oregon, and California coastal and Sierra species in the southwest, all mixing with native northwestern taxa to create a wide array of habitats. Title: Oregon Natural Areas Plan Author: Oregon Natural Heritage Advisory Council Year: 2010 The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, deserts, marshes, estuaries, dunes, rocky headlands, lakes and streams. There are a number of reasons it is so diverse. First are the extremes of climate, with rainfall ranging from over 200 inches a year along Oregon’s north coast, to less than 7 inches a year in the Alvord Desert, and temperatures from the very mild banana belt along the coast near the California border to the extremes of the high alpine areas of the Wallowa Mountains. Secondly, Oregon is diverse geographically and geologically, having ancient serpentine landscapes in the Siskiyou Mountains and recent volcanics in the Cascades and the deepest gorge in North America at Hells Canyon. Lastly, Oregon is a floristic crossroads, with arctic boreal species finding their southern limit, Rocky Mountain species common in northeastern Oregon, Great Basin species in southeastern Oregon, and California coastal and Sierra species in the southwest, all mixing with native northwestern taxa to create a wide array of habitats. Close

• 23. [Article] Klamath River Canyon vegetation and road treatments decision record #1

  6 pp. Maps. The project analysis area is located within and adjacent to the Klamath River Canyon in southern Oregon (see map 1). Captured July 2, 2008.

  Citation × Citation Citation Abstract Copy Title: Klamath River Canyon vegetation and road treatments decision record #1 Author: United States. Bureau of Land Management. Lakeview District Year: 2008 6 pp. Maps. The project analysis area is located within and adjacent to the Klamath River Canyon in southern Oregon (see map 1). Captured July 2, 2008. Title: Klamath River Canyon vegetation and road treatments decision record #1 Author: United States. Bureau of Land Management. Lakeview District Year: 2008 6 pp. Maps. The project analysis area is located within and adjacent to the Klamath River Canyon in southern Oregon (see map 1). Captured July 2, 2008. Close

• 24. [Article] Movements, habitat associations, and survival of Columbian white-tailed deer in western Oregon

  Columbian white-tailed deer (Odocoileus virginianus leucurus, CWTD) are a geographically isolated and federally endangered sub-species for which there is a paucity of recent ecological information. I described ...

  Citation × Citation Citation Abstract Copy Title: Movements, habitat associations, and survival of Columbian white-tailed deer in western Oregon Author: Ricca, Mark A. Columbian white-tailed deer (Odocoileus virginianus leucurus, CWTD) are a geographically isolated and federally endangered sub-species for which there is a paucity of recent ecological information. I described and examined sources of variation in spatial use patterns (i.e. home range, areas of concentrated use, and movements), habitat associations, and survival for adult and fawn CWTD in Douglas County, Oregon. I radio-collared and monitored 64 adult CWTD and 36 newborn fawn CWTD from ca. December 1995 - September 1998. Locations for adults were obtained from September 1996 - December 1998. Locations for fawns were obtained from June - September, 1997 - 1998. Spatial use estimates for adults tended to be variable among deer. Mean 95% fixed kernel home range size was 74.5 ha (CV = 83%), while areas of concentrated use averaged 8.5 ha (CV = 93%). The sexes appeared to be partitioning space because males had larger home ranges, areas of concentrated use (which are analogous to core areas), and movements than females. Deer inhabiting human-influenced areas (suburban deer) consistently exhibited smaller movements and used less space than those away from human influence (wild deer). Mean home range size, area of concentrated use size, and distance between successive locations was generally greatest in fall and lowest in winter. Site fidelity to seasonal home ranges and areas of concentrated use was lowest between fall-winter and summer-fall. Unexpectedly, size of home ranges and areas of concentrated use were positively correlated with cover type heterogeneity. Annual adult survival rates averaged 0.73. Neither annual survival rates nor functions differed by sex or type. Survival over the entire 3 year study was low (0.39). Most deer died in winter from a combination of emaciation and disease and generally were in poor body condition. Oak-hardwood woodland, riparian, and oak-hardwood savanna shrub were the most frequently used cover types. On an annual basis, the majority of deer (31%) selected riparian areas. The frequency of selection of all non-riparian cover types was < 13%, as most deer either exhibited avoidance or 'neutral selection-avoidance' of these cover types. The probability of use for a particular patch was positively associated with proximity to a stream for 56% of all deer. However, the relative amount of edge within a particular patch had little effect on the odds of use. Patterns of use and selection tended to be similar between the sexes, but suburban deer used conifer and yard cover types more frequently than wild deer. Use and selection of cover types by deer did not significantly differ among seasons. CWTD also demonstrated higher use for more open cover types during crepuscular and nocturnal periods. Areas of concentrated use were random with respect to cover type composition, but were significantly associated with proximity ([less than or equal to] 200 m) to streams. Home ranges, areas of concentrated use, and movements of fawns were variable but tended to reflect their sedentary nature. Home range and area of concentrated use size were not correlated with percent coverage of oak-hardwood woodland, riparian, or shrub dominated cover types. Habitat use patterns were characterized by frequent use of oak-hardwood woodland and riparian cover types, and areas within 200 m of streams. These habitat use patterns may represent some degree of rigidity in habitat composition within fawning areas. However, there was no apparent selection of cover types or distance to stream classes within areas of concentrated use. Fawn survival to 6 months was low (0.15, 95% CI = 0.009 - 0.308) and was most similar to estimates from previous CWTD studies and unhunted white-tailed deer populations. Mortality was highest during approximately the first 1 - 1.5 months of life. There were no differences in survival to 6 months by sex, but females had significantly higher survival during the neonatal period than males. Survival time was unrelated to both movements and use of oak-hardwood woodland and riparian cover types. Predation was the most frequent (n = 8) cause of death, followed by abandonment (n = 5). Overall, adult CWTD were sedentary, dispersal movements were not readily apparent, and survival rates were within the range of rates reported for other white-tailed deer populations. Adult CWTD also exhibited a degree of specialization for riparian areas, and generalized use patterns for other cover types. CWTD fawns tended to use small areas, exhibited frequent use of oak-hardwood woodlands and areas near streams. Survival rates of adults and fawns may be suggestive of density dependent population responses. Title: Movements, habitat associations, and survival of Columbian white-tailed deer in western Oregon Author: Ricca, Mark A. Columbian white-tailed deer (Odocoileus virginianus leucurus, CWTD) are a geographically isolated and federally endangered sub-species for which there is a paucity of recent ecological information. I described and examined sources of variation in spatial use patterns (i.e. home range, areas of concentrated use, and movements), habitat associations, and survival for adult and fawn CWTD in Douglas County, Oregon. I radio-collared and monitored 64 adult CWTD and 36 newborn fawn CWTD from ca. December 1995 - September 1998. Locations for adults were obtained from September 1996 - December 1998. Locations for fawns were obtained from June - September, 1997 - 1998. Spatial use estimates for adults tended to be variable among deer. Mean 95% fixed kernel home range size was 74.5 ha (CV = 83%), while areas of concentrated use averaged 8.5 ha (CV = 93%). The sexes appeared to be partitioning space because males had larger home ranges, areas of concentrated use (which are analogous to core areas), and movements than females. Deer inhabiting human-influenced areas (suburban deer) consistently exhibited smaller movements and used less space than those away from human influence (wild deer). Mean home range size, area of concentrated use size, and distance between successive locations was generally greatest in fall and lowest in winter. Site fidelity to seasonal home ranges and areas of concentrated use was lowest between fall-winter and summer-fall. Unexpectedly, size of home ranges and areas of concentrated use were positively correlated with cover type heterogeneity. Annual adult survival rates averaged 0.73. Neither annual survival rates nor functions differed by sex or type. Survival over the entire 3 year study was low (0.39). Most deer died in winter from a combination of emaciation and disease and generally were in poor body condition. Oak-hardwood woodland, riparian, and oak-hardwood savanna shrub were the most frequently used cover types. On an annual basis, the majority of deer (31%) selected riparian areas. The frequency of selection of all non-riparian cover types was < 13%, as most deer either exhibited avoidance or 'neutral selection-avoidance' of these cover types. The probability of use for a particular patch was positively associated with proximity to a stream for 56% of all deer. However, the relative amount of edge within a particular patch had little effect on the odds of use. Patterns of use and selection tended to be similar between the sexes, but suburban deer used conifer and yard cover types more frequently than wild deer. Use and selection of cover types by deer did not significantly differ among seasons. CWTD also demonstrated higher use for more open cover types during crepuscular and nocturnal periods. Areas of concentrated use were random with respect to cover type composition, but were significantly associated with proximity ([less than or equal to] 200 m) to streams. Home ranges, areas of concentrated use, and movements of fawns were variable but tended to reflect their sedentary nature. Home range and area of concentrated use size were not correlated with percent coverage of oak-hardwood woodland, riparian, or shrub dominated cover types. Habitat use patterns were characterized by frequent use of oak-hardwood woodland and riparian cover types, and areas within 200 m of streams. These habitat use patterns may represent some degree of rigidity in habitat composition within fawning areas. However, there was no apparent selection of cover types or distance to stream classes within areas of concentrated use. Fawn survival to 6 months was low (0.15, 95% CI = 0.009 - 0.308) and was most similar to estimates from previous CWTD studies and unhunted white-tailed deer populations. Mortality was highest during approximately the first 1 - 1.5 months of life. There were no differences in survival to 6 months by sex, but females had significantly higher survival during the neonatal period than males. Survival time was unrelated to both movements and use of oak-hardwood woodland and riparian cover types. Predation was the most frequent (n = 8) cause of death, followed by abandonment (n = 5). Overall, adult CWTD were sedentary, dispersal movements were not readily apparent, and survival rates were within the range of rates reported for other white-tailed deer populations. Adult CWTD also exhibited a degree of specialization for riparian areas, and generalized use patterns for other cover types. CWTD fawns tended to use small areas, exhibited frequent use of oak-hardwood woodlands and areas near streams. Survival rates of adults and fawns may be suggestive of density dependent population responses. Close

• 25. [Article] Private forests, public policy : oak conservation on family forests in Oregon’s Willamette Valley

  In the United States, many of the thorniest natural resource conflicts occur on private lands. This is especially true in the Willamette Valley of Western Oregon where the hallmark habitat type, Oregon ...

  Citation × Citation Citation Abstract Copy Title: Private forests, public policy : oak conservation on family forests in Oregon’s Willamette Valley Author: Fischer, Alexandra Paige In the United States, many of the thorniest natural resource conflicts occur on private lands. This is especially true in the Willamette Valley of Western Oregon where the hallmark habitat type, Oregon white oak woodland and savanna, is imperiled. Almost exclusively found on private land, Oregon white oak is threatened by urban development, vineyards, tree plantations, and the elimination of the periodic fires to which it is adapted. While regional and local planners, conservationists and natural resource agencies are attempting to conserve oak, little effort has been made to understand the social group in whose hands the fate of much of the resource rests: family forest owners. This paper presents a case study of oak conservation on family forestlands in Oregon. Through individual and group interviews and building upon social constructionism and interpretive policy analysis, this research investigates how two stakeholder groups—family forest owners and natural resource professionals—frame the problem of oak’s decline and opportunities and constraints for its conservation. It also analyzes some of the conservation policies that informants suggested for oak. By illuminating owners’ needs, capacities and constraints, and identifying areas of common ground and conflict in informants’ interpretive frames, this research identifies ways to reach out to a target group with empathy, facilitate cooperation between stakeholders, and avert potential conflicts that arise from conservation strategies. Title: Private forests, public policy : oak conservation on family forests in Oregon’s Willamette Valley Author: Fischer, Alexandra Paige In the United States, many of the thorniest natural resource conflicts occur on private lands. This is especially true in the Willamette Valley of Western Oregon where the hallmark habitat type, Oregon white oak woodland and savanna, is imperiled. Almost exclusively found on private land, Oregon white oak is threatened by urban development, vineyards, tree plantations, and the elimination of the periodic fires to which it is adapted. While regional and local planners, conservationists and natural resource agencies are attempting to conserve oak, little effort has been made to understand the social group in whose hands the fate of much of the resource rests: family forest owners. This paper presents a case study of oak conservation on family forestlands in Oregon. Through individual and group interviews and building upon social constructionism and interpretive policy analysis, this research investigates how two stakeholder groups—family forest owners and natural resource professionals—frame the problem of oak’s decline and opportunities and constraints for its conservation. It also analyzes some of the conservation policies that informants suggested for oak. By illuminating owners’ needs, capacities and constraints, and identifying areas of common ground and conflict in informants’ interpretive frames, this research identifies ways to reach out to a target group with empathy, facilitate cooperation between stakeholders, and avert potential conflicts that arise from conservation strategies. Close

• 26. [Article] Oak Habitat Mapping and Monitoring in the Southern Eugene Ridgeline

  Submitted to the Undergraduate Library Research Award scholarship competition: 2010-2011. 63 p.

  Citation × Citation Citation Abstract Copy Title: Oak Habitat Mapping and Monitoring in the Southern Eugene Ridgeline Author: Bigalke, Brittany, Kimmy, Ertel, Liston, Matthew, Park, Alex, Russell, Alexandria, Silva, Matt Year: 2011 Submitted to the Undergraduate Library Research Award scholarship competition: 2010-2011. 63 p. Title: Oak Habitat Mapping and Monitoring in the Southern Eugene Ridgeline Author: Bigalke, Brittany, Kimmy, Ertel, Liston, Matthew, Park, Alex, Russell, Alexandria, Silva, Matt Year: 2011 Submitted to the Undergraduate Library Research Award scholarship competition: 2010-2011. 63 p. Close

• 27. [Article] Granary-site selection by acorn woodpeckers in Benton County, Oregon

  The acorn woodpecker (Melanerpes formicivorus) is among the most common primary cavity nesters of the Oregon white oak (Quercus garryana) woodlands. Understanding their selection of granary sites is important ...

  Citation × Citation Citation Abstract Copy Title: Granary-site selection by acorn woodpeckers in Benton County, Oregon Author: Johnson, Eric M. The acorn woodpecker (Melanerpes formicivorus) is among the most common primary cavity nesters of the Oregon white oak (Quercus garryana) woodlands. Understanding their selection of granary sites is important in evaluating habitat quality and management actions. I hypothesized that granary locations would be consistent with the optimal foraging theory. Site characters were selected that were hypothesized to affect granary profitability. I compared site characteristics of granaries and non-granaries within the home ranges of 20 colonies in Benton County, Oregon during the winter of 2001. Granaries had greater oak basal area (x*=104 ± 16 dm2), shorter brush height (x*=-26 ± 7 cm), larger diameter at breast height (dbh) (x*=l1 ± 4 cm). Of 14 a priori models considered, I determined that the Forage Model was the best predictor of granary presence. This model is based solely on the oak basal area variable, a measure of potential acorn production. Increased acorn production in the vicinity of granaries is likely beneficial to the birds because minimal effort is expended in caching maximum forage. Title: Granary-site selection by acorn woodpeckers in Benton County, Oregon Author: Johnson, Eric M. The acorn woodpecker (Melanerpes formicivorus) is among the most common primary cavity nesters of the Oregon white oak (Quercus garryana) woodlands. Understanding their selection of granary sites is important in evaluating habitat quality and management actions. I hypothesized that granary locations would be consistent with the optimal foraging theory. Site characters were selected that were hypothesized to affect granary profitability. I compared site characteristics of granaries and non-granaries within the home ranges of 20 colonies in Benton County, Oregon during the winter of 2001. Granaries had greater oak basal area (x*=104 ± 16 dm2), shorter brush height (x*=-26 ± 7 cm), larger diameter at breast height (dbh) (x*=l1 ± 4 cm). Of 14 a priori models considered, I determined that the Forage Model was the best predictor of granary presence. This model is based solely on the oak basal area variable, a measure of potential acorn production. Increased acorn production in the vicinity of granaries is likely beneficial to the birds because minimal effort is expended in caching maximum forage. Close

• 28. [Article] Historical Vegetation of Central Southwest Oregon, Based on GLO Survey Notes : Final Report to USDI Bureau of Land Management, Medford District

  Historical vegetation at the time of European settlement is of great interest to both the public and land managers, but is poorly documented. One source of data are the earliest land survey records of ...

  Citation × Citation Citation Abstract Copy Title: Historical Vegetation of Central Southwest Oregon, Based on GLO Survey Notes : Final Report to USDI Bureau of Land Management, Medford District Author: Hickman, O. Eugene, Christy, John A. Year: 2011 Historical vegetation at the time of European settlement is of great interest to both the public and land managers, but is poorly documented. One source of data are the earliest land survey records of the General Land Office (GLO). Rectangular township surveys in Southwest Oregon were initiated in the mid 1850’s as settlers began to claim homesteads in the Bear Creek Valley surrounding what is now Medford. We examined GLO land survey field notes and plats (maps) accompanying the surveys, transcribed GLO landscape data into an Access database, and classified the data set into very general vegetation types for mapping. About 89 vegetation types (subclasses) were described for mapping historic vegetation, distinguished by major differences in plant composition and topographic features. Tree density was estimated from section line descriptions and witness tree spacing at corners, and was used to classify stands into tree classes. These types then were combined into broad “Vegetation Classes” for mapping (i.e. savanna, shrubland, forest, prairie). Classifying and mapping historical vegetation occurred on about 418,500 acres in an earlier OSU study, and about 720,700 acres in this BLM study, located in Jackson and Josephine Counties. The authors merged results from these adjacent GLO studies, expanding the coverage to approximately 1.14 million acres (49 townships). Modern soil surveys of the study area helped the authors interpret GLO data and draw vegetation boundaries. About 44% of the landscape was closed upland forest, 41% woodland, 1.4% riparian forest, 2% oak or conifer savanna, 1% shrublands, and 11% bottomland meadow or upland prairie. Forest types ranged from moist, mixed conifer uplands to dry valley ponderosa pine-hardwood grassland. Large areas of prairie and mixed oak-conifer woodland dominated many low elevation locations on plains, foothills, and especially clayey terraces or southern slopes near what is now Medford. Nearly 115 plant species or plant groups were identified by the surveyors, mostly trees and shrubs. Some were misidentified and not easily interpreted by the authors when archaic names were used by the surveyors. Grazing quality was frequently noted as surveyors attempted to describe land productivity for livestock. Historic baseline plant data is presented for broad landscape transects and sometimes by topographic positions, but is limited by the sketchy nature of the original surveyor notes. Nearly 350 homestead parcels of various sizes were claimed in the study, as identified in GLO survey notes and on Donation Land Claim maps, showing how quickly settlement occurred in the study area after gold was discovered in 1851. Most early homesteads included prairie or oak savanna, which was open and more easily converted to farmland or pasture. Early saw mills, grist mills, fields, roads, water diversions and major Indian trails were also identified and transcribed from the GLO records. Title: Historical Vegetation of Central Southwest Oregon, Based on GLO Survey Notes : Final Report to USDI Bureau of Land Management, Medford District Author: Hickman, O. Eugene, Christy, John A. Year: 2011 Historical vegetation at the time of European settlement is of great interest to both the public and land managers, but is poorly documented. One source of data are the earliest land survey records of the General Land Office (GLO). Rectangular township surveys in Southwest Oregon were initiated in the mid 1850’s as settlers began to claim homesteads in the Bear Creek Valley surrounding what is now Medford. We examined GLO land survey field notes and plats (maps) accompanying the surveys, transcribed GLO landscape data into an Access database, and classified the data set into very general vegetation types for mapping. About 89 vegetation types (subclasses) were described for mapping historic vegetation, distinguished by major differences in plant composition and topographic features. Tree density was estimated from section line descriptions and witness tree spacing at corners, and was used to classify stands into tree classes. These types then were combined into broad “Vegetation Classes” for mapping (i.e. savanna, shrubland, forest, prairie). Classifying and mapping historical vegetation occurred on about 418,500 acres in an earlier OSU study, and about 720,700 acres in this BLM study, located in Jackson and Josephine Counties. The authors merged results from these adjacent GLO studies, expanding the coverage to approximately 1.14 million acres (49 townships). Modern soil surveys of the study area helped the authors interpret GLO data and draw vegetation boundaries. About 44% of the landscape was closed upland forest, 41% woodland, 1.4% riparian forest, 2% oak or conifer savanna, 1% shrublands, and 11% bottomland meadow or upland prairie. Forest types ranged from moist, mixed conifer uplands to dry valley ponderosa pine-hardwood grassland. Large areas of prairie and mixed oak-conifer woodland dominated many low elevation locations on plains, foothills, and especially clayey terraces or southern slopes near what is now Medford. Nearly 115 plant species or plant groups were identified by the surveyors, mostly trees and shrubs. Some were misidentified and not easily interpreted by the authors when archaic names were used by the surveyors. Grazing quality was frequently noted as surveyors attempted to describe land productivity for livestock. Historic baseline plant data is presented for broad landscape transects and sometimes by topographic positions, but is limited by the sketchy nature of the original surveyor notes. Nearly 350 homestead parcels of various sizes were claimed in the study, as identified in GLO survey notes and on Donation Land Claim maps, showing how quickly settlement occurred in the study area after gold was discovered in 1851. Most early homesteads included prairie or oak savanna, which was open and more easily converted to farmland or pasture. Early saw mills, grist mills, fields, roads, water diversions and major Indian trails were also identified and transcribed from the GLO records. Close

• 29. [Article] Historical vegetation of central southwest Oregon, based on GLO survey notes : final report to USDI Bureau of Land Management, Medford District

  Final report to USDI Bureau of Land Management. Medford District, Oregon

  Citation × Citation Citation Abstract Copy Title: Historical vegetation of central southwest Oregon, based on GLO survey notes : final report to USDI Bureau of Land Management, Medford District Author: Hickman, O. Eugene, Christy, John A., The Institute for Natural Resources Final report to USDI Bureau of Land Management. Medford District, Oregon Title: Historical vegetation of central southwest Oregon, based on GLO survey notes : final report to USDI Bureau of Land Management, Medford District Author: Hickman, O. Eugene, Christy, John A., The Institute for Natural Resources Final report to USDI Bureau of Land Management. Medford District, Oregon Close

• 30. [Article] The seasonal occurrence and distribution of stoneflies (Plecoptera) of a western Oregon stream

  Plecoptera were collected from four sampling stations selected to represent a range of conditions on Oak Creek, a small woodland stream originating in the foothills of the Oregon Coast Range. The elevation ...

  Citation × Citation Citation Abstract Copy Title: The seasonal occurrence and distribution of stoneflies (Plecoptera) of a western Oregon stream Author: Kerst, Cary Dean Plecoptera were collected from four sampling stations selected to represent a range of conditions on Oak Creek, a small woodland stream originating in the foothills of the Oregon Coast Range. The elevation of Site I was 700 ft. while the lowest site was located at 225 ft. Monthly benthos samples were taken for one year from a riffle and glide section at each site using a stovepipe sampler (6 in. dia. ) and a standard tropical fish net. Samples were sorted in the laboratory and Plecoptera identified and placed into 1 mm size classes. Emergence of adults was measured for 13 months using a tent-shaped trap (1 m²) at each site. Traps were checked once or twice weekly. Forty-two species of Plecoptera were found in Oak Creek. The number of species is very large when compared with other studies. The stonefly fauna is fairly similar to that reported 35 years ago. Thirty-seven of the 42 species complete emergence during the spring. Temporal separation is marked in the emergence periods of Nemoura and Leuctra. Examples of split emergence periods and early emergence of males were found. Life cycle information is given for a number of species and genera. Using the Shannon-Wiener function, diversity of emerging adults ranks by season as: Spring > Summer > Winter > Fall. The diversity of the sites on a yearly basis is: II > I > III > IV. Using a percentage of similarity index it is concluded that Sites I and II are very similar. Site III is intermediate while Site IV is quite different. A number of examples of restricted distributions are cited. These examples illustrate that differences in longitudinal distribution are important in ecological segregation. Herbivorous stoneflies (suborder Filipalpia) comprise a greater proportion of the fauna at the upper site while predaceous stoneflies (Setipalpia) predominate in the lower areas. Water depth and amounts of leaves and silt are important factors in determining the distribution of stoneflies. Most species are abundant in leaf drifts. Microhabitat selection does not appear to be rigorous. Title: The seasonal occurrence and distribution of stoneflies (Plecoptera) of a western Oregon stream Author: Kerst, Cary Dean Plecoptera were collected from four sampling stations selected to represent a range of conditions on Oak Creek, a small woodland stream originating in the foothills of the Oregon Coast Range. The elevation of Site I was 700 ft. while the lowest site was located at 225 ft. Monthly benthos samples were taken for one year from a riffle and glide section at each site using a stovepipe sampler (6 in. dia. ) and a standard tropical fish net. Samples were sorted in the laboratory and Plecoptera identified and placed into 1 mm size classes. Emergence of adults was measured for 13 months using a tent-shaped trap (1 m²) at each site. Traps were checked once or twice weekly. Forty-two species of Plecoptera were found in Oak Creek. The number of species is very large when compared with other studies. The stonefly fauna is fairly similar to that reported 35 years ago. Thirty-seven of the 42 species complete emergence during the spring. Temporal separation is marked in the emergence periods of Nemoura and Leuctra. Examples of split emergence periods and early emergence of males were found. Life cycle information is given for a number of species and genera. Using the Shannon-Wiener function, diversity of emerging adults ranks by season as: Spring > Summer > Winter > Fall. The diversity of the sites on a yearly basis is: II > I > III > IV. Using a percentage of similarity index it is concluded that Sites I and II are very similar. Site III is intermediate while Site IV is quite different. A number of examples of restricted distributions are cited. These examples illustrate that differences in longitudinal distribution are important in ecological segregation. Herbivorous stoneflies (suborder Filipalpia) comprise a greater proportion of the fauna at the upper site while predaceous stoneflies (Setipalpia) predominate in the lower areas. Water depth and amounts of leaves and silt are important factors in determining the distribution of stoneflies. Most species are abundant in leaf drifts. Microhabitat selection does not appear to be rigorous. Close