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• 21. [Article] Some factors controlling the establishment and distribution of Quercus agrifolia Nee and Q. engelmannii Greene in certain southern California oak woodlands

  The structure of two oak woodland types in the Santa Rosa region of the Santa Ana Mountains of southern California has been described by Zuill (1967). One type called the grass oak woodland (GOW) is composed ...

  Citation × Citation Citation Abstract Copy Title: Some factors controlling the establishment and distribution of Quercus agrifolia Nee and Q. engelmannii Greene in certain southern California oak woodlands Author: Snow, Gerald Eldon The structure of two oak woodland types in the Santa Rosa region of the Santa Ana Mountains of southern California has been described by Zuill (1967). One type called the grass oak woodland (GOW) is composed mainly of Q. engelmannii on hills and slopes. The other type called the dense oak woodland (DOW) is composed equally of Q. engelmannii and Q. agrifolia with twice the density of the GOW and is located in valleys with granite rock outcrops. An apparent lack of seedlings and saplings was noted in the area. The present study focuses on an explanation for the distribution patterns of the two oak species in the field and the factors which might be most important in influencing seedling establishment. Quercus agrifolia is restricted to cool moist protected locations on the north side and in fractures of rock outcrops because its acorns are sensitive to moisture loss on air drying, require constantly moist conditions for one to five weeks for water uptake to effect germination and have very rapid shoot development after germination. Seedlings may be intolerant of high temperatures in open grass litter, and seedlings and saplings appear less tolerant of fire than Q. engelmannii, which would also tend to restrict Q. agrifolia to protected locations around rock outcrops. The distribution of Q. engelmannii trees with respect to rock outcrops does not differ from a random distribution and the few that are associated with outcrops show a random distribution with respect to position around outcrops. The occurrence of Q. engelmannii in more open exposed habitats may be due to its acorns' tolerance to moisture loss on air drying, their ability to germinate with little or n6 additional water uptake, its self-planting mechanism and delayed shoot development, and the drought deciduous habit of seedlings and their tolerance to fire. In the laboratory the drought capable of killing 50% of the seedlings is about 100 bars soil moisture tension for Q. engelmannii and about 250 bars for Q. agrifolia. The survival of Q. agrifolia under a greater degree of soil drought is mainly attributable to its higher root: shoot ratio under these particular conditions. Seedlings of both species would be expected to survive any drought recorded in the field between 1968 and 1970 at their expected rooting depth. After a very wet rainy season none of the mature trees experienced any moisture stress by the end of the dry season even though the near surface soils were quite dry. After a quite dry year trees in the DOW showed significantly greater moisture stress than those on a hilltop in the GOW. The moisture stress measurements of trees and soil moisture determinations down to 86 cm indicate that all the mature trees are rooted mainly below 86 cm. At least one large tree is apparently rooted down to 6 m. A planting of Q. agrifolia acorns that were buried to simulate squirrel caches survived to establish many more seedlings than surface planted acorns due mainly to protection from predation and drying and to conditions affording good radicle penetration. In an open planting cattle destroyed all the seedlings that were established while most of the seedlings remained in a planting closed to cattle. The complete lack of oak reproduction in open habitats and the restriction of reproduction for both species to rock outcrops since 1910 is attributable to cattle grazing, which has been continuous since about 1910. The last reproduction of Q. engelmannii in the GOW's without outcrops and the peak reproduction of Q. agrifolia in the DOW occurred between 1890 and 1910. This may be explained partly by the fact that for at least 10 years during this time livestock were excluded due to a dry land farming operation in the area. More than half of the living Q. engelmannii were established before any known influence of European men and their livestock (1820) and there has been a general decline in establishment since then. This might be expected since they usually occur in open and exposed habitats which would be most subject to grazing pressure. There was a simultaneous establishment and rapid buildup of the Q. agrifolia population around rock outcrops in the DOW with the entrance of European man and his livestock which may be due to ground squirrels depositing acorns around their burrows which are often associated with rock outcrops. These squirrels are known to come into new areas after disturbance by man. Also about this time filaree, a new preferred food source for squirrels (in addition to acorns), was being established on California range lands which probably resulted in an increase in the squirrel population. An effective squirrel poisoning program was begun in the 1920's and this may also account for the decreased establishment of Q. agrifolia since this time even around rock outcrops. Title: Some factors controlling the establishment and distribution of Quercus agrifolia Nee and Q. engelmannii Greene in certain southern California oak woodlands Author: Snow, Gerald Eldon The structure of two oak woodland types in the Santa Rosa region of the Santa Ana Mountains of southern California has been described by Zuill (1967). One type called the grass oak woodland (GOW) is composed mainly of Q. engelmannii on hills and slopes. The other type called the dense oak woodland (DOW) is composed equally of Q. engelmannii and Q. agrifolia with twice the density of the GOW and is located in valleys with granite rock outcrops. An apparent lack of seedlings and saplings was noted in the area. The present study focuses on an explanation for the distribution patterns of the two oak species in the field and the factors which might be most important in influencing seedling establishment. Quercus agrifolia is restricted to cool moist protected locations on the north side and in fractures of rock outcrops because its acorns are sensitive to moisture loss on air drying, require constantly moist conditions for one to five weeks for water uptake to effect germination and have very rapid shoot development after germination. Seedlings may be intolerant of high temperatures in open grass litter, and seedlings and saplings appear less tolerant of fire than Q. engelmannii, which would also tend to restrict Q. agrifolia to protected locations around rock outcrops. The distribution of Q. engelmannii trees with respect to rock outcrops does not differ from a random distribution and the few that are associated with outcrops show a random distribution with respect to position around outcrops. The occurrence of Q. engelmannii in more open exposed habitats may be due to its acorns' tolerance to moisture loss on air drying, their ability to germinate with little or n6 additional water uptake, its self-planting mechanism and delayed shoot development, and the drought deciduous habit of seedlings and their tolerance to fire. In the laboratory the drought capable of killing 50% of the seedlings is about 100 bars soil moisture tension for Q. engelmannii and about 250 bars for Q. agrifolia. The survival of Q. agrifolia under a greater degree of soil drought is mainly attributable to its higher root: shoot ratio under these particular conditions. Seedlings of both species would be expected to survive any drought recorded in the field between 1968 and 1970 at their expected rooting depth. After a very wet rainy season none of the mature trees experienced any moisture stress by the end of the dry season even though the near surface soils were quite dry. After a quite dry year trees in the DOW showed significantly greater moisture stress than those on a hilltop in the GOW. The moisture stress measurements of trees and soil moisture determinations down to 86 cm indicate that all the mature trees are rooted mainly below 86 cm. At least one large tree is apparently rooted down to 6 m. A planting of Q. agrifolia acorns that were buried to simulate squirrel caches survived to establish many more seedlings than surface planted acorns due mainly to protection from predation and drying and to conditions affording good radicle penetration. In an open planting cattle destroyed all the seedlings that were established while most of the seedlings remained in a planting closed to cattle. The complete lack of oak reproduction in open habitats and the restriction of reproduction for both species to rock outcrops since 1910 is attributable to cattle grazing, which has been continuous since about 1910. The last reproduction of Q. engelmannii in the GOW's without outcrops and the peak reproduction of Q. agrifolia in the DOW occurred between 1890 and 1910. This may be explained partly by the fact that for at least 10 years during this time livestock were excluded due to a dry land farming operation in the area. More than half of the living Q. engelmannii were established before any known influence of European men and their livestock (1820) and there has been a general decline in establishment since then. This might be expected since they usually occur in open and exposed habitats which would be most subject to grazing pressure. There was a simultaneous establishment and rapid buildup of the Q. agrifolia population around rock outcrops in the DOW with the entrance of European man and his livestock which may be due to ground squirrels depositing acorns around their burrows which are often associated with rock outcrops. These squirrels are known to come into new areas after disturbance by man. Also about this time filaree, a new preferred food source for squirrels (in addition to acorns), was being established on California range lands which probably resulted in an increase in the squirrel population. An effective squirrel poisoning program was begun in the 1920's and this may also account for the decreased establishment of Q. agrifolia since this time even around rock outcrops. Close

• 22. [Article] Relative abundance and habitat associations of small mammals in two forest types in southern Oregon

  I studied small-mammal communities and their response to grazing in mixed-conifer forests and oak woodlands in the Cascade-Siskiyou National Monument in southern Oregon. My objectives were to (1) compare ...

  Citation × Citation Citation Abstract Copy Title: Relative abundance and habitat associations of small mammals in two forest types in southern Oregon Author: Johnston, Aaron N. I studied small-mammal communities and their response to grazing in mixed-conifer forests and oak woodlands in the Cascade-Siskiyou National Monument in southern Oregon. My objectives were to (1) compare small-mammal communities among forest types and grazing intensities, (2) identify riparian affiliated species, and (3) describe microhabitat associations. Over two years, I trapped 1,617 individual small mammals representing 20 species. Mixed-conifer forests had more species and greater abundances of small mammals than oak woodlands, but there were no significant differences between the forest types in species richness or diversity at the stand level, as most sites had 3 to 5 species at any given time. Evenness was higher in oak woodlands compared to mixed-conifer forests because of lower dominance by Peromyscus maniculatus and fewer rare species. P. maniculatus dominated both forest types. Neurotrichus gibbsii, Tamias amoenus, Tamias siskiyou, Neotoma cinerea, Clethrionomys californicus, Microtus californicus, Microtus longicaudus, and Microtus montanus were found only in mixed-conifer forests, whereas Peromyscus boylii were trapped exclusively in oak woodlands. Although the two forest types shared 10 species, Sorex trowbridgii and Peromyscus maniculatus were significantly (P < 0.05) more abundant in mixed-conifer forests, whereas Sorex vagrans, Reithrodontomys megalotis, Peromyscus truei, and Neotoma fuscipes were significantly more abundant in oak woodlands. Microtus townsendii was the only species that was equally abundant in both forest types, but was found exclusively within meadow sites in mixed-conifer forests. I found no significant differences in species richness, diversity, and evenness between heavy and lightly grazed sites. However, mean mammalian biomass was 138 g/ha lower in heavily grazed sites, and abundances were 89.3% of those in lightly grazed sites. Cumulative biomass and abundance across heavily grazed sites were 65% and 80%, respectively, of that in lightly grazed sites. Several relatively large species (e.g. Neotoma spp. and Microtus spp.) were less abundant or absent in heavily grazed sites. My results support previous studies that found lower abundances of small mammals associated with herbaceous cover (e.g. Microtus spp.) in heavily grazed sites and little or no effect for species associated with open habitats (e.g. Tamias spp.). I found significantly (P < 0.05) lower abundances of S. trowbridgii (conifer), Peromyscus spp. (oak), N. cinerea (conifer), N. fuscipes (oak), M. longicaudus (conifer), and M. californicus (conifer) in heavy versus lightly grazed sites. There were also fewer T. siskiyou, R. megalotis, and M. townsendii captured in heavy versus lightly grazed sites, but the differences were not significant (P > 0.05). S. vagrans and T. amoenus were significantly more abundant in heavily grazed sites. Sample sizes for the remaining species were too small for comparison (n < 6). N. gibbsii, C. californicus, and M. californicus were captured exclusively in lightly grazed sites; only T. amoenus was captured exclusively in a heavily grazed site. There was a significant (P < 0.05) decrease in the odds of catching R. megalotis, N. cinerea, N. fuscipes, and M. longicaudus on heavy versus lightly grazed sites after accounting for microhabitat associations and potential confounding factors. Odds of capture were significantly (P < 0.05) lower for P. maniculatus in heavy versus lightly grazed sites in oak woodlands, but there was less difference in abundance between grazing intensities in mixed-conifer forests. There was some evidence to suggest that grazing decreased the odds of capturing M. townsendii in riparian areas. Although I found significantly (P < 0.05) fewer S. trowbridgii in heavily grazed sites, my analysis indicated that microhabitat associations rather than grazing explained the difference. Grazing appeared to increase the use of riparian areas by Tamias spp. by removing herbaceous cover and increasing bare ground. I described microhabitat associations for 10 species and found a suite of species (S. trowbridgii, T. amoenus, T. siskiyou, N. cinerea) that were positively associated with coarse woody debris and/or snags. R. megalotis, M. longicaudus, and M. townsendii were affiliated with, but not obligated, to riparian areas. P. maniculatus were ubiquitous, but abundances were also higher in riparian areas compared with uplands. T. siskiyou and P. truei appeared to be associated with uplands rather than riparian areas. Although I captured few S. vagrans, N. gibbsii, M. californicus, and M. montanus, they were found in either riparian areas or around spring seeps, which support previous studies. My results supported the importance of riparian areas to small mammals as suggested by previous studies. Title: Relative abundance and habitat associations of small mammals in two forest types in southern Oregon Author: Johnston, Aaron N. I studied small-mammal communities and their response to grazing in mixed-conifer forests and oak woodlands in the Cascade-Siskiyou National Monument in southern Oregon. My objectives were to (1) compare small-mammal communities among forest types and grazing intensities, (2) identify riparian affiliated species, and (3) describe microhabitat associations. Over two years, I trapped 1,617 individual small mammals representing 20 species. Mixed-conifer forests had more species and greater abundances of small mammals than oak woodlands, but there were no significant differences between the forest types in species richness or diversity at the stand level, as most sites had 3 to 5 species at any given time. Evenness was higher in oak woodlands compared to mixed-conifer forests because of lower dominance by Peromyscus maniculatus and fewer rare species. P. maniculatus dominated both forest types. Neurotrichus gibbsii, Tamias amoenus, Tamias siskiyou, Neotoma cinerea, Clethrionomys californicus, Microtus californicus, Microtus longicaudus, and Microtus montanus were found only in mixed-conifer forests, whereas Peromyscus boylii were trapped exclusively in oak woodlands. Although the two forest types shared 10 species, Sorex trowbridgii and Peromyscus maniculatus were significantly (P < 0.05) more abundant in mixed-conifer forests, whereas Sorex vagrans, Reithrodontomys megalotis, Peromyscus truei, and Neotoma fuscipes were significantly more abundant in oak woodlands. Microtus townsendii was the only species that was equally abundant in both forest types, but was found exclusively within meadow sites in mixed-conifer forests. I found no significant differences in species richness, diversity, and evenness between heavy and lightly grazed sites. However, mean mammalian biomass was 138 g/ha lower in heavily grazed sites, and abundances were 89.3% of those in lightly grazed sites. Cumulative biomass and abundance across heavily grazed sites were 65% and 80%, respectively, of that in lightly grazed sites. Several relatively large species (e.g. Neotoma spp. and Microtus spp.) were less abundant or absent in heavily grazed sites. My results support previous studies that found lower abundances of small mammals associated with herbaceous cover (e.g. Microtus spp.) in heavily grazed sites and little or no effect for species associated with open habitats (e.g. Tamias spp.). I found significantly (P < 0.05) lower abundances of S. trowbridgii (conifer), Peromyscus spp. (oak), N. cinerea (conifer), N. fuscipes (oak), M. longicaudus (conifer), and M. californicus (conifer) in heavy versus lightly grazed sites. There were also fewer T. siskiyou, R. megalotis, and M. townsendii captured in heavy versus lightly grazed sites, but the differences were not significant (P > 0.05). S. vagrans and T. amoenus were significantly more abundant in heavily grazed sites. Sample sizes for the remaining species were too small for comparison (n < 6). N. gibbsii, C. californicus, and M. californicus were captured exclusively in lightly grazed sites; only T. amoenus was captured exclusively in a heavily grazed site. There was a significant (P < 0.05) decrease in the odds of catching R. megalotis, N. cinerea, N. fuscipes, and M. longicaudus on heavy versus lightly grazed sites after accounting for microhabitat associations and potential confounding factors. Odds of capture were significantly (P < 0.05) lower for P. maniculatus in heavy versus lightly grazed sites in oak woodlands, but there was less difference in abundance between grazing intensities in mixed-conifer forests. There was some evidence to suggest that grazing decreased the odds of capturing M. townsendii in riparian areas. Although I found significantly (P < 0.05) fewer S. trowbridgii in heavily grazed sites, my analysis indicated that microhabitat associations rather than grazing explained the difference. Grazing appeared to increase the use of riparian areas by Tamias spp. by removing herbaceous cover and increasing bare ground. I described microhabitat associations for 10 species and found a suite of species (S. trowbridgii, T. amoenus, T. siskiyou, N. cinerea) that were positively associated with coarse woody debris and/or snags. R. megalotis, M. longicaudus, and M. townsendii were affiliated with, but not obligated, to riparian areas. P. maniculatus were ubiquitous, but abundances were also higher in riparian areas compared with uplands. T. siskiyou and P. truei appeared to be associated with uplands rather than riparian areas. Although I captured few S. vagrans, N. gibbsii, M. californicus, and M. montanus, they were found in either riparian areas or around spring seeps, which support previous studies. My results supported the importance of riparian areas to small mammals as suggested by previous studies. Close

• 23. [Article] Mental and biophysical terrains of biodiversity : conservation of oak woodland on family forest

  This research analyzes how family forest owners conceptualize biodiversity in one high-conservation value area of oak woodland in the Willamette Valley of Western Oregon. Oregon white oak (Quercus garyanna) ...

  Citation × Citation Citation Abstract Copy Title: Mental and biophysical terrains of biodiversity : conservation of oak woodland on family forest Author: Fischer, Alexandra Paige This research analyzes how family forest owners conceptualize biodiversity in one high-conservation value area of oak woodland in the Willamette Valley of Western Oregon. Oregon white oak (Quercus garyanna) woodland, one of the most biologically diverse ecotypes in the state of Oregon, is in decline. Much of the oak ecotype occurs on the lands of family forest owners. Understanding owners' conceptions of biodiversity is important for the conservation of this important resource. Theories from sociology, social psychology, and policy analysis argue that information about people's knowledge and beliefs is important for understanding and influencing their behavior. This research explores the mental and biophysical terrains of owners' relationships with biodiversity. Through interdisciplinary methods - including concept mapping, in-depth interviews, property mapping and field reconnaissance - it explores the meanings that people give to biodiversity on their family properties. Findings indicate that 1) owners are knowledgeable about the key elements of biodiversity, and 2) their use of this knowledge in management reflects their beliefs about human relationships with nature and external market constraints. Title: Mental and biophysical terrains of biodiversity : conservation of oak woodland on family forest Author: Fischer, Alexandra Paige This research analyzes how family forest owners conceptualize biodiversity in one high-conservation value area of oak woodland in the Willamette Valley of Western Oregon. Oregon white oak (Quercus garyanna) woodland, one of the most biologically diverse ecotypes in the state of Oregon, is in decline. Much of the oak ecotype occurs on the lands of family forest owners. Understanding owners' conceptions of biodiversity is important for the conservation of this important resource. Theories from sociology, social psychology, and policy analysis argue that information about people's knowledge and beliefs is important for understanding and influencing their behavior. This research explores the mental and biophysical terrains of owners' relationships with biodiversity. Through interdisciplinary methods - including concept mapping, in-depth interviews, property mapping and field reconnaissance - it explores the meanings that people give to biodiversity on their family properties. Findings indicate that 1) owners are knowledgeable about the key elements of biodiversity, and 2) their use of this knowledge in management reflects their beliefs about human relationships with nature and external market constraints. Close

• 24. [Article] Stand structures of Oregon white oak (Quercus garryana) woodlands and their relationships to the environment in southwestern Oregon

  Large areas of non-coniferous communities in southwestern Oregon are thinned to reduce fire hazard and accomplish ecosystem restoration, under the assumption that current fuel loads are unnaturally high. ...

  Citation × Citation Citation Abstract Copy Title: Stand structures of Oregon white oak (Quercus garryana) woodlands and their relationships to the environment in southwestern Oregon Author: Gilligan, Laurie A. Large areas of non-coniferous communities in southwestern Oregon are thinned to reduce fire hazard and accomplish ecosystem restoration, under the assumption that current fuel loads are unnaturally high. Although Oregon white oak (Quercus garryana) woodlands are a characteristic landscape component in this region, little is known about their current or historical stand structures. Managers lack information on which to base restoration-focused fuel reduction prescriptions. I inventoried 40 Oregon white oak dominated woodlands across 2 study areas in southwestern Oregon, and describe here their stand characteristics and age structures. I assessed whether these varied systematically with site conditions or recorded fire history. Stands included various proportions of single- and multiple-stemmed trees and a range of tree densities and diameter- and age-class distributions. Variables that may indicate site moisture status were weakly associated with multivariate gradients in stand structure, and fire history also appeared related to several stand structures. Peak establishment of living Oregon white oaks generally occurred during 1850-1890, sometimes occurred in the early 1900’s, and recruitment rates were low post-fire suppression. Recruitment of sapling-sized oak trees (< 10 cm dbh, 1.3 m tall) was generally low and their ages ranged from 5 to 164 yr; they were not necessarily recent recruits. The range of stand and age structures, and the variation in their apparent relations to site factors and history, suggests that site-by-site management prescriptions may more effectively accomplish restoration goals than do current treatments. Prescriptions should include follow-up monitoring with attention to effects on oak recruitment. Title: Stand structures of Oregon white oak (Quercus garryana) woodlands and their relationships to the environment in southwestern Oregon Author: Gilligan, Laurie A. Large areas of non-coniferous communities in southwestern Oregon are thinned to reduce fire hazard and accomplish ecosystem restoration, under the assumption that current fuel loads are unnaturally high. Although Oregon white oak (Quercus garryana) woodlands are a characteristic landscape component in this region, little is known about their current or historical stand structures. Managers lack information on which to base restoration-focused fuel reduction prescriptions. I inventoried 40 Oregon white oak dominated woodlands across 2 study areas in southwestern Oregon, and describe here their stand characteristics and age structures. I assessed whether these varied systematically with site conditions or recorded fire history. Stands included various proportions of single- and multiple-stemmed trees and a range of tree densities and diameter- and age-class distributions. Variables that may indicate site moisture status were weakly associated with multivariate gradients in stand structure, and fire history also appeared related to several stand structures. Peak establishment of living Oregon white oaks generally occurred during 1850-1890, sometimes occurred in the early 1900’s, and recruitment rates were low post-fire suppression. Recruitment of sapling-sized oak trees (< 10 cm dbh, 1.3 m tall) was generally low and their ages ranged from 5 to 164 yr; they were not necessarily recent recruits. The range of stand and age structures, and the variation in their apparent relations to site factors and history, suggests that site-by-site management prescriptions may more effectively accomplish restoration goals than do current treatments. Prescriptions should include follow-up monitoring with attention to effects on oak recruitment. Close

• 25. [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

• 26. [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

• 27. [Article] White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon

  Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) ...

  Citation × Citation Citation Abstract Copy Title: White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon Author: Viste-Sparkman, Karen Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) are experiencing long-term population declines in the Willamette Valley of Oregon, where they are historically associated with oak woodlands. As secondary cavity-nesters, white-breasted nuthatches may be limited by the availability of existing cavities for nesting and roosting. Oak vegetation in the Willamette Valley has changed since European-American settlement times from vast areas of open oak savanna to isolated closed-canopy stands separated by agricultural fields. We examined nuthatch density, nest cavity selection, and nest success in relation to oak woodland structure and landscape context. We conducted point transect surveys in 3 strata: woodland interiors, large woodland edges, and small woodlands. We located and monitored nuthatch nests and sampled vegetation at nest locations and matching random locations around each nest. Woodland structure and edge density were measured at a 178-m radius (home range) scale, and landscape context was measured using vegetation cover within a 1-km radius around point transects and nests. We used program DISTANCE to fit detection functions and calculate nuthatch densities. We used conditional logistic regression to compare nest locations with random locations, and analyzed nest success with Mayfield logistic regression. White-breasted nuthatch density was significantly higher in small woodlands than in edges of large woodlands, which had higher nuthatch density than woodland interiors. Density of nuthatches increased with a combination of oak cover within a 1-km radius of the point, edge density within a 178-m radius, and number of oak trees >50 cm diameter at breast height (dbh) within a 100-m radius. Nest cavities were situated in oak trees containing more cavities than random oak trees that had cavities, and oak trees used as nest trees had a larger dbh than oak trees within random plots. Local woodland structure at nest locations was characterized by larger trees, measured by greater mean dbh, canopy cover, and basal area of oaks than random locations within the home range. Nest success in natural cavities was 71% and was not predicted by attributes of nest cavities, nest trees, local woodland structure at nests, woodland structure at the home range scale, or landscape context. These results suggest that the most suitable habitat for white-breasted nuthatches in the Willamette Valley includes oak woodlands in close proximity to one another with a high proportion of edge and mature oak trees. Managers should preserve trees containing cavities and large oak trees whenever possible. Thinning of small oaks and removal of conifers in oak woodlands to create more open, savanna-like conditions may also promote the development of larger oaks with more spreading branches, providing more opportunities for cavities to form and more foraging surface area for nuthatches. Title: White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon Author: Viste-Sparkman, Karen Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) are experiencing long-term population declines in the Willamette Valley of Oregon, where they are historically associated with oak woodlands. As secondary cavity-nesters, white-breasted nuthatches may be limited by the availability of existing cavities for nesting and roosting. Oak vegetation in the Willamette Valley has changed since European-American settlement times from vast areas of open oak savanna to isolated closed-canopy stands separated by agricultural fields. We examined nuthatch density, nest cavity selection, and nest success in relation to oak woodland structure and landscape context. We conducted point transect surveys in 3 strata: woodland interiors, large woodland edges, and small woodlands. We located and monitored nuthatch nests and sampled vegetation at nest locations and matching random locations around each nest. Woodland structure and edge density were measured at a 178-m radius (home range) scale, and landscape context was measured using vegetation cover within a 1-km radius around point transects and nests. We used program DISTANCE to fit detection functions and calculate nuthatch densities. We used conditional logistic regression to compare nest locations with random locations, and analyzed nest success with Mayfield logistic regression. White-breasted nuthatch density was significantly higher in small woodlands than in edges of large woodlands, which had higher nuthatch density than woodland interiors. Density of nuthatches increased with a combination of oak cover within a 1-km radius of the point, edge density within a 178-m radius, and number of oak trees >50 cm diameter at breast height (dbh) within a 100-m radius. Nest cavities were situated in oak trees containing more cavities than random oak trees that had cavities, and oak trees used as nest trees had a larger dbh than oak trees within random plots. Local woodland structure at nest locations was characterized by larger trees, measured by greater mean dbh, canopy cover, and basal area of oaks than random locations within the home range. Nest success in natural cavities was 71% and was not predicted by attributes of nest cavities, nest trees, local woodland structure at nests, woodland structure at the home range scale, or landscape context. These results suggest that the most suitable habitat for white-breasted nuthatches in the Willamette Valley includes oak woodlands in close proximity to one another with a high proportion of edge and mature oak trees. Managers should preserve trees containing cavities and large oak trees whenever possible. Thinning of small oaks and removal of conifers in oak woodlands to create more open, savanna-like conditions may also promote the development of larger oaks with more spreading branches, providing more opportunities for cavities to form and more foraging surface area for nuthatches. Close

• 28. [Article] Stand Structures of Oregon White Oak Woodlands, Regeneration, and Their Relationships to the Environment in Southwestern Oregon

  This is the publisher’s final pdf. The published article is copyrighted by Northwest Scientific Association and can be found at: http://www.northwestscience.org/.

  Citation × Citation Citation Abstract Copy Title: Stand Structures of Oregon White Oak Woodlands, Regeneration, and Their Relationships to the Environment in Southwestern Oregon Author: Gilligan, Laurie A., Muir, Patricia S. This is the publisher’s final pdf. The published article is copyrighted by Northwest Scientific Association and can be found at: http://www.northwestscience.org/. Title: Stand Structures of Oregon White Oak Woodlands, Regeneration, and Their Relationships to the Environment in Southwestern Oregon Author: Gilligan, Laurie A., Muir, Patricia S. This is the publisher’s final pdf. The published article is copyrighted by Northwest Scientific Association and can be found at: http://www.northwestscience.org/. Close

• 29. [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

• 30. [Article] Food web studies in an oak woodland eco-system

  Citation × Citation Citation Abstract Copy Title: Food web studies in an oak woodland eco-system Author: Hamilton, Grace Anne Title: Food web studies in an oak woodland eco-system Author: Hamilton, Grace Anne Close