Search

Search Results

• 31. [Article] Synecology of the white-oak (Quercus garryana Douglas) woodlands of the Willamette Valley, Oregon

  Quercus garryana dominated plant communities are found in the interior coastal valleys and on foothills from southeastern Vancouver Island, British Columbia, south to San Francisco, California. They occur ...

  Citation × Citation Citation Abstract Copy Title: Synecology of the white-oak (Quercus garryana Douglas) woodlands of the Willamette Valley, Oregon Author: Thilenius, John F., 1931- Quercus garryana dominated plant communities are found in the interior coastal valleys and on foothills from southeastern Vancouver Island, British Columbia, south to San Francisco, California. They occur as savannas, intermixed with a variety of conifers, and in almost pure stands. The diversity of habitats occupied by the species and the variety of vegetation associated with it provide an opportunity for a basic synecological investigation of plant communities having a common, important member. The study was designed to describe the floristic composition and structure of the Quercus garryana communities, to determine their ecological relation to the physical environment, and clarify successional status. It provides a framework for future autecological investigations of the component species and is directed at furnishing a fuller understanding of the synecology of an important segment of the vegetation of western Oregon. Two levels of sampling were used during the study. The first was a rapidly applied, qualitative method. This reconnaissance technique was designed to provide an assessment of dominance, size-class distribution, and composition of the species comprising the vegetation. Information on influential habitat factors was also obtained. Sampling at this level enabled the examination of many stands, provided a record of each stand, and served as the basis for the selection of stands for more quantitative sampling. One hundred forty stands were examined during the reconnaissance phase of the study. Subjective evaluation of these stands supported by an analysis using marginal punch cards determined that only a few species were dominating the tall shrub and low shrub-herbaceous layers of the understory and that certain combinations of these dominant species were being repeated geographically through the study area. The second sampling phase was based on the reconnaissance information and was designed to provide a quantitative record of the species complexes or plant communities delineated during reconnaissance. This method was applicable by a single investigator and measured the dominance, frequency, size distribution, and density of tree species; and the percent coverage and percent frequency of shrubs, herbs, and grasses. Soil profile descriptions were made in each stand where the vegetation was quantitatively sampled. Salient features of the physical environment were also recorded as were indications of past and present land uses. Forty seven stands were sampled. Quercus garryana was the cverstory tree dominant in all of these stands. The understory pecies were found to fall into four major communities. From mesic to xeric these were: the Corylus cornuta/Polystichum munitum community, the Prunus avium/Symphoricarpos albus community, the Amelanchier alnifolia/Symphoricarpos albus community, and the Rhus diversiloba community. These communities were named for the species usually dominating the tall shrub and low shrub layers. Seven soil series served as the substrate of these communities; Steiwer, Carlton, Peavine, Dixonville, Nekia, Olympic, and Amity. The understory plant communities of the Quercus forest show considerable variation and intergradation. Changes are a matter of shifts in species dominance rather than alterations in species composition. The absence of environmental extremes in the Willamette Valley and heavy present and historical land use have increased this intergradation. The presence of large, open-form Quercus garryana trees surrounded by smaller forest-form trees indicates that the present Quercus forests have developed from a savanna. The cause of this change in gross physiognomy is probably the control of the repeated ground fires which swept the pre-settlement savanna. Mature Quercus trees are not harmed by ground fires, but such fires would tend to keep dense reproduction from occurring. The present abundance of Rhus diversiloba in the under story may be directly related to heavy livestock grazing. The interconnected root system of ground cover and liana-form Rhus provides the species with a grazing resistance mechanism. The liana Rhus is out of reach of grazing animals. Photosynthate transferred from the liana to the ground cover plants would aid the latter in retaining vigor even under heavy grazing pressure. Thus it would have an advantage over other plants that were also being grazed, eventually becoming the ground layer dominant. Both Pseudotsuga menziesii and Acer macrophyllum appear to be successional to Quercus garryana. Acer is better adapted to mesic sites than Quercus. Pseudotsuga will succeed Quercus on less mesic sites. The successional trends are promoted by livestock grazing which opens up the ground layer and facilitates seedling establishment especially for Pseudotsuga. On some sites Prunus avium, an introduced species, is becoming part of the overstory canopy. It reproduces vigorously in its own shade and will become an important member of the Quercus forest in the future. Quercus garryana reproduction was more abundant on drier, exposed sites and the species seems to be able to perpetuate itself on these locations. Title: Synecology of the white-oak (Quercus garryana Douglas) woodlands of the Willamette Valley, Oregon Author: Thilenius, John F., 1931- Quercus garryana dominated plant communities are found in the interior coastal valleys and on foothills from southeastern Vancouver Island, British Columbia, south to San Francisco, California. They occur as savannas, intermixed with a variety of conifers, and in almost pure stands. The diversity of habitats occupied by the species and the variety of vegetation associated with it provide an opportunity for a basic synecological investigation of plant communities having a common, important member. The study was designed to describe the floristic composition and structure of the Quercus garryana communities, to determine their ecological relation to the physical environment, and clarify successional status. It provides a framework for future autecological investigations of the component species and is directed at furnishing a fuller understanding of the synecology of an important segment of the vegetation of western Oregon. Two levels of sampling were used during the study. The first was a rapidly applied, qualitative method. This reconnaissance technique was designed to provide an assessment of dominance, size-class distribution, and composition of the species comprising the vegetation. Information on influential habitat factors was also obtained. Sampling at this level enabled the examination of many stands, provided a record of each stand, and served as the basis for the selection of stands for more quantitative sampling. One hundred forty stands were examined during the reconnaissance phase of the study. Subjective evaluation of these stands supported by an analysis using marginal punch cards determined that only a few species were dominating the tall shrub and low shrub-herbaceous layers of the understory and that certain combinations of these dominant species were being repeated geographically through the study area. The second sampling phase was based on the reconnaissance information and was designed to provide a quantitative record of the species complexes or plant communities delineated during reconnaissance. This method was applicable by a single investigator and measured the dominance, frequency, size distribution, and density of tree species; and the percent coverage and percent frequency of shrubs, herbs, and grasses. Soil profile descriptions were made in each stand where the vegetation was quantitatively sampled. Salient features of the physical environment were also recorded as were indications of past and present land uses. Forty seven stands were sampled. Quercus garryana was the cverstory tree dominant in all of these stands. The understory pecies were found to fall into four major communities. From mesic to xeric these were: the Corylus cornuta/Polystichum munitum community, the Prunus avium/Symphoricarpos albus community, the Amelanchier alnifolia/Symphoricarpos albus community, and the Rhus diversiloba community. These communities were named for the species usually dominating the tall shrub and low shrub layers. Seven soil series served as the substrate of these communities; Steiwer, Carlton, Peavine, Dixonville, Nekia, Olympic, and Amity. The understory plant communities of the Quercus forest show considerable variation and intergradation. Changes are a matter of shifts in species dominance rather than alterations in species composition. The absence of environmental extremes in the Willamette Valley and heavy present and historical land use have increased this intergradation. The presence of large, open-form Quercus garryana trees surrounded by smaller forest-form trees indicates that the present Quercus forests have developed from a savanna. The cause of this change in gross physiognomy is probably the control of the repeated ground fires which swept the pre-settlement savanna. Mature Quercus trees are not harmed by ground fires, but such fires would tend to keep dense reproduction from occurring. The present abundance of Rhus diversiloba in the under story may be directly related to heavy livestock grazing. The interconnected root system of ground cover and liana-form Rhus provides the species with a grazing resistance mechanism. The liana Rhus is out of reach of grazing animals. Photosynthate transferred from the liana to the ground cover plants would aid the latter in retaining vigor even under heavy grazing pressure. Thus it would have an advantage over other plants that were also being grazed, eventually becoming the ground layer dominant. Both Pseudotsuga menziesii and Acer macrophyllum appear to be successional to Quercus garryana. Acer is better adapted to mesic sites than Quercus. Pseudotsuga will succeed Quercus on less mesic sites. The successional trends are promoted by livestock grazing which opens up the ground layer and facilitates seedling establishment especially for Pseudotsuga. On some sites Prunus avium, an introduced species, is becoming part of the overstory canopy. It reproduces vigorously in its own shade and will become an important member of the Quercus forest in the future. Quercus garryana reproduction was more abundant on drier, exposed sites and the species seems to be able to perpetuate itself on these locations. Close

• 32. [Article] The logistics of working with poison oak

  This appendix to my dissertation documents how I worked with poison oak plants as a subject of study for three years. It contains practical suggestions for people who have my level of sensitivity (low ...

  Citation × Citation Citation Abstract Copy Title: The logistics of working with poison oak Author: Gartner, Barbara Lachenbruch This appendix to my dissertation documents how I worked with poison oak plants as a subject of study for three years. It contains practical suggestions for people who have my level of sensitivity (low to moderate). I expect it may be useful for hikers, mountain bikers, woodland owners, people in roads departments, and researchers who are out in areas that have a lot of poison oak. The contact dermatitis from poison ivy is very very similar, so I expect this will be of use for people who deal with poison ivy, as well. Title: The logistics of working with poison oak Author: Gartner, Barbara Lachenbruch This appendix to my dissertation documents how I worked with poison oak plants as a subject of study for three years. It contains practical suggestions for people who have my level of sensitivity (low to moderate). I expect it may be useful for hikers, mountain bikers, woodland owners, people in roads departments, and researchers who are out in areas that have a lot of poison oak. The contact dermatitis from poison ivy is very very similar, so I expect this will be of use for people who deal with poison ivy, as well. Close

• 33. [Article] Status and habitat use of Columbian white-tailed deer in Douglas County, Oregon

  A study conducted May 1978-December 1980 determined that the present geographic range of Columbian white-tailed deer, Odocoileus virginianus leucurus, (CWTD) in Douglas County, Oregon encompassed 1199km2. ...

  Citation × Citation Citation Abstract Copy Title: Status and habitat use of Columbian white-tailed deer in Douglas County, Oregon Author: Smith, Winston Paul A study conducted May 1978-December 1980 determined that the present geographic range of Columbian white-tailed deer, Odocoileus virginianus leucurus, (CWTD) in Douglas County, Oregon encompassed 1199km2. The area was predominately a Quercus woodland community, typical of the Interior Valley Zone of western Oregon. The CWTD distribution was not contiguous throughout its range; the highest densities occurred along the North Umpqua River between Glide and Wilbur. Ten habitats were described: grassland, grass-shrub, oak-savanna, open oak, closed oak, oak-conifer, oak-madrone, madrone, riparian and conifer. CWTD exhibited a preference (P<0.05) for grass-shrub, oak-savanna, open oak, closed oak, riparian and conifer habitats while selecting the remaining habitats less frequently (P<0.05) than was expected from corresponding availabilities. Grassland use increased proportionally with biomass production of grasses and forbs during the spring and with mean monthly precipitation in the fall; CWTD utilized grasslands more frequently (P<0.05) during the fall than in the spring. Fawns utilized. woodland and brushland habitats more frequently (P<0.05) than yearlings and adults; yearlings utilized grasslands more often (P<0.05) and grassshrub habitats less frequently (P<0.05) than adults. Adult males occurred less frequently (P<0.05) in grass-shrub and more often (P<0.05) in conifer habitats than adult females, particularly in the summer. The population estimates for the 2745 ha study area were 628 and 740 CWTD representing an average density of 22.9 and 27.0 CWTD per km2, respectively. There existed a positive association (P<0.05) between distribution and abundance of CWTD and the juxtaposition of suitable habitat to the North Umpqua River. A positive curvilinear relationship between CWTD density and percent woodland cover was observed; maximum densities occurred in areas supporting approximately 50% woodland cover. Fall herd composition estimates were 52 fawns and 30 bucks per 100 does. Secondary sex ratios departed from unity (P<0.05) favoring males when summer rainfall was abnormally low. Malnutrition and vehicle-inflicted injuries accounted for the largest proportion of known mortality. The ultimate cause of mortality among yearling and adult males and females was apparently associated with reproduction; these activities were more demanding (P<0.05) on males. The median age at death for males (1.65) was less (P<0.05) than that observed for females (2.15). Fawn survival and recruitment varied inversely with existing population densities and winter severity. Parasite loads were light and corresponded with observed seasonal differences in the physical condition of CWTD. Convex polygon estimates of home range size for CWTD females and males averaged 21.1 ha and 32.8 ha, respectively. Elliptical home range estimates were invariably larger than corresponding convex polygon estimates and averaged 44.5 ha and 47.1 ha for females and males, respectively. Home ranges were stable between years; however, males and females demonstrated significant shifts in center of activity among the seasons, behaviors observed to be associated with rutting and fawning activities, respectively. CWTD and black-tailed deer demonstrated a local geographic and ecological segregation; there was a significant inverse correlation in the relative densities of the two species, and sympatric populations of black-tailed deer and CWTD differed (P<0.05) in their frequency of occurrence among the ten habitats. Local geographic distributions and habitat-use patterns indicated that within preferred habitats, CWTD competitively excluded black-tailed deer. Lowland riparian systems played a major role in CWTD ecology, representing an important environmental component in the life history of the species and serving as corridors of dispersal and recent geographic expansion. Title: Status and habitat use of Columbian white-tailed deer in Douglas County, Oregon Author: Smith, Winston Paul A study conducted May 1978-December 1980 determined that the present geographic range of Columbian white-tailed deer, Odocoileus virginianus leucurus, (CWTD) in Douglas County, Oregon encompassed 1199km2. The area was predominately a Quercus woodland community, typical of the Interior Valley Zone of western Oregon. The CWTD distribution was not contiguous throughout its range; the highest densities occurred along the North Umpqua River between Glide and Wilbur. Ten habitats were described: grassland, grass-shrub, oak-savanna, open oak, closed oak, oak-conifer, oak-madrone, madrone, riparian and conifer. CWTD exhibited a preference (P<0.05) for grass-shrub, oak-savanna, open oak, closed oak, riparian and conifer habitats while selecting the remaining habitats less frequently (P<0.05) than was expected from corresponding availabilities. Grassland use increased proportionally with biomass production of grasses and forbs during the spring and with mean monthly precipitation in the fall; CWTD utilized grasslands more frequently (P<0.05) during the fall than in the spring. Fawns utilized. woodland and brushland habitats more frequently (P<0.05) than yearlings and adults; yearlings utilized grasslands more often (P<0.05) and grassshrub habitats less frequently (P<0.05) than adults. Adult males occurred less frequently (P<0.05) in grass-shrub and more often (P<0.05) in conifer habitats than adult females, particularly in the summer. The population estimates for the 2745 ha study area were 628 and 740 CWTD representing an average density of 22.9 and 27.0 CWTD per km2, respectively. There existed a positive association (P<0.05) between distribution and abundance of CWTD and the juxtaposition of suitable habitat to the North Umpqua River. A positive curvilinear relationship between CWTD density and percent woodland cover was observed; maximum densities occurred in areas supporting approximately 50% woodland cover. Fall herd composition estimates were 52 fawns and 30 bucks per 100 does. Secondary sex ratios departed from unity (P<0.05) favoring males when summer rainfall was abnormally low. Malnutrition and vehicle-inflicted injuries accounted for the largest proportion of known mortality. The ultimate cause of mortality among yearling and adult males and females was apparently associated with reproduction; these activities were more demanding (P<0.05) on males. The median age at death for males (1.65) was less (P<0.05) than that observed for females (2.15). Fawn survival and recruitment varied inversely with existing population densities and winter severity. Parasite loads were light and corresponded with observed seasonal differences in the physical condition of CWTD. Convex polygon estimates of home range size for CWTD females and males averaged 21.1 ha and 32.8 ha, respectively. Elliptical home range estimates were invariably larger than corresponding convex polygon estimates and averaged 44.5 ha and 47.1 ha for females and males, respectively. Home ranges were stable between years; however, males and females demonstrated significant shifts in center of activity among the seasons, behaviors observed to be associated with rutting and fawning activities, respectively. CWTD and black-tailed deer demonstrated a local geographic and ecological segregation; there was a significant inverse correlation in the relative densities of the two species, and sympatric populations of black-tailed deer and CWTD differed (P<0.05) in their frequency of occurrence among the ten habitats. Local geographic distributions and habitat-use patterns indicated that within preferred habitats, CWTD competitively excluded black-tailed deer. Lowland riparian systems played a major role in CWTD ecology, representing an important environmental component in the life history of the species and serving as corridors of dispersal and recent geographic expansion. Close

• 34. [Article] Classification of oak vegetation in the Willamette Valley

  A plant community classification was developed describing the comprehensive variation of oak vegetation currently occupying the Willamette Valley Ecoregion of western Oregon. Multivariate statistical analyses ...

  Citation × Citation Citation Abstract Copy Title: Classification of oak vegetation in the Willamette Valley Author: Fitzpatrick, Greg, Kertis, Jane, Alverson, Ed, Buechling, Arne A plant community classification was developed describing the comprehensive variation of oak vegetation currently occupying the Willamette Valley Ecoregion of western Oregon. Multivariate statistical analyses were used to classify field collected floristic and habitat data. Field sampling targeted minimally managed, homogenous vegetation stands with a significant oak component occupying at least 0.5 ha. Potential habitat locations were identified from local expert knowledge, data from The Nature Conservancy’s previous conservation planning efforts, and an interpretation of high resolution NAIP imagery. Potential oak habitats were digitized in a GIS and a random selection of sites stratifying significant environmental gradients was generated in order capture the range of oak habitat variability. Precise sample plot locations were predetermined and established at digitized stand centroids. Field sampling was based on relevé plot data collection methods and included ocular estimates of species cover. A total of 350 stands of oak vegetation were sampled over two field seasons. Two-way indicator species analysis (TWINSPAN) was used as an exploratory tool to identify potential patterns in species cover data and Detrended Correspondence Analysis (DCA) was used to delimit final plant community types. Nine vegetation classes were described from ordinations including seven forest / woodland types and two savannas Title: Classification of oak vegetation in the Willamette Valley Author: Fitzpatrick, Greg, Kertis, Jane, Alverson, Ed, Buechling, Arne A plant community classification was developed describing the comprehensive variation of oak vegetation currently occupying the Willamette Valley Ecoregion of western Oregon. Multivariate statistical analyses were used to classify field collected floristic and habitat data. Field sampling targeted minimally managed, homogenous vegetation stands with a significant oak component occupying at least 0.5 ha. Potential habitat locations were identified from local expert knowledge, data from The Nature Conservancy’s previous conservation planning efforts, and an interpretation of high resolution NAIP imagery. Potential oak habitats were digitized in a GIS and a random selection of sites stratifying significant environmental gradients was generated in order capture the range of oak habitat variability. Precise sample plot locations were predetermined and established at digitized stand centroids. Field sampling was based on relevé plot data collection methods and included ocular estimates of species cover. A total of 350 stands of oak vegetation were sampled over two field seasons. Two-way indicator species analysis (TWINSPAN) was used as an exploratory tool to identify potential patterns in species cover data and Detrended Correspondence Analysis (DCA) was used to delimit final plant community types. Nine vegetation classes were described from ordinations including seven forest / woodland types and two savannas Close

• 35. [Article] Edaphic Controls Over Succession In Former Oak Savanna, Willamette Valley, Oregon

  xii, 87 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.

  Citation × Citation Citation Abstract Copy Title: Edaphic Controls Over Succession In Former Oak Savanna, Willamette Valley, Oregon Author: Murphy, Meghan Suzanne, 1979- Year: 2008 xii, 87 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. Title: Edaphic Controls Over Succession In Former Oak Savanna, Willamette Valley, Oregon Author: Murphy, Meghan Suzanne, 1979- Year: 2008 xii, 87 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. Close

• 36. [Article] Maxfield Creek density management upland habitat restoration final decision and decision rationale

  19 pp. Tables, maps. Township 10 South, Range 5 West, Sections 19 and 29, Township 10 South, Range 6 West, Section 22. Captured July 18, 2007.

  Citation × Citation Citation Abstract Copy Title: Maxfield Creek density management upland habitat restoration final decision and decision rationale Author: United States. Bureau of Land Management. Salem District Year: 2009, 2007 19 pp. Tables, maps. Township 10 South, Range 5 West, Sections 19 and 29, Township 10 South, Range 6 West, Section 22. Captured July 18, 2007. Title: Maxfield Creek density management upland habitat restoration final decision and decision rationale Author: United States. Bureau of Land Management. Salem District Year: 2009, 2007 19 pp. Tables, maps. Township 10 South, Range 5 West, Sections 19 and 29, Township 10 South, Range 6 West, Section 22. Captured July 18, 2007. Close

• 37. [Article] The great fires : Indian burning and catastrophic forest fire patterns of the Oregon Coast Range, 1491-1951

  The purpose of this study is to examine the relationship between land management practices of Indian communities prior to contact with Europeans and the nature or character of subsequent catastrophic forest fires ...

  Citation × Citation Citation Abstract Copy Title: The great fires : Indian burning and catastrophic forest fire patterns of the Oregon Coast Range, 1491-1951 Author: Zybach, Bob The purpose of this study is to examine the relationship between land management practices of Indian communities prior to contact with Europeans and the nature or character of subsequent catastrophic forest fires in the Oregon Coast Range. The research focus is spatial and temporal patterns of Indian burning across the landscape from 1491 until 1848, and corresponding patterns of catastrophic fire events from 1849 until 1951. Archival and anthropological research methods were used to obtain early surveys, maps, drawings, photographs, interviews, Geographic Information Systems (GIS) inventories, eyewitness accounts and other sources of evidence that document fire history. Data were tabulated, mapped, and digitized as new GIS layers for purposes of comparative analysis. An abundance of historical evidence was found to exist that is useful for reconstructing precontact vegetation patterns and human burning practices in western Oregon. The data also proved useful for documenting local and regional forest fire histories. Precontact Indians used fire to produce landscape patterns of trails, patches, fields, woodlands, forests and grasslands that varied from time to time and place to place, partly due to demographic, cultural, topographic, and climatic differences that existed throughout the Coast Range. Native plants were systematically managed by local Indian families in even-aged stands, usually dominated by a single species, throughout all river basins of the study area. Oak, filberts, camas, wapato, tarweed, yampah, strawberries, huckleberries, brackenfern, nettles, and other plants were raised in select areas by all known tribes, over long periods of time. However, current scientific and policy assumptions regarding the abundance and extent of precontact western Oregon old-growth forests may be in error. This study demonstrates a high rate of coincidence between the land management practices of precontact Indian communities, and the causes, timing, boundaries, severity, and extent of subsequent catastrophic forest fires in the same areas. Information provided by this study should be of value to researchers, wildlife managers, forest landowners, and others with an interest in the history and resources of the Oregon Coast Range. Title: The great fires : Indian burning and catastrophic forest fire patterns of the Oregon Coast Range, 1491-1951 Author: Zybach, Bob The purpose of this study is to examine the relationship between land management practices of Indian communities prior to contact with Europeans and the nature or character of subsequent catastrophic forest fires in the Oregon Coast Range. The research focus is spatial and temporal patterns of Indian burning across the landscape from 1491 until 1848, and corresponding patterns of catastrophic fire events from 1849 until 1951. Archival and anthropological research methods were used to obtain early surveys, maps, drawings, photographs, interviews, Geographic Information Systems (GIS) inventories, eyewitness accounts and other sources of evidence that document fire history. Data were tabulated, mapped, and digitized as new GIS layers for purposes of comparative analysis. An abundance of historical evidence was found to exist that is useful for reconstructing precontact vegetation patterns and human burning practices in western Oregon. The data also proved useful for documenting local and regional forest fire histories. Precontact Indians used fire to produce landscape patterns of trails, patches, fields, woodlands, forests and grasslands that varied from time to time and place to place, partly due to demographic, cultural, topographic, and climatic differences that existed throughout the Coast Range. Native plants were systematically managed by local Indian families in even-aged stands, usually dominated by a single species, throughout all river basins of the study area. Oak, filberts, camas, wapato, tarweed, yampah, strawberries, huckleberries, brackenfern, nettles, and other plants were raised in select areas by all known tribes, over long periods of time. However, current scientific and policy assumptions regarding the abundance and extent of precontact western Oregon old-growth forests may be in error. This study demonstrates a high rate of coincidence between the land management practices of precontact Indian communities, and the causes, timing, boundaries, severity, and extent of subsequent catastrophic forest fires in the same areas. Information provided by this study should be of value to researchers, wildlife managers, forest landowners, and others with an interest in the history and resources of the Oregon Coast Range. Close