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• 151. [Article] Life history variables of Dicamptodon salamanders

  It is good practice to fully understand components of an ecosystem if we hope to preserve its biodiversity. A problem is that we know very little about some organisms and nothing of others. Studies that ...

  Citation × Citation Citation Abstract Copy Title: Life history variables of Dicamptodon salamanders Author: Wagner, Lisa A. It is good practice to fully understand components of an ecosystem if we hope to preserve its biodiversity. A problem is that we know very little about some organisms and nothing of others. Studies that investigate an organism’s basic biological, ecological and physiological life history variables advance our knowledge of the species of interest and also offer insight about community structure and function. In this thesis I explore courtship behaviors, metamorphic tendencies and hematological parameters in two species of Dicamptodon salamanders (D. copei and D. tenebrosus). Ecologists examine blood to assess hematological responses to a plethora of factors including hormonal changes, parasites, reproductive status and environmental stressors. While hematologic principles are fairly conserved in vertebrates, blood tissue has evolved to match the organism with its environment and there is considerable diversity in hematological parameters across taxa. Therefore, it is necessary to collect species specific baseline data for comparison. In Chapter 2, I quantified relative white blood cells and erythrocyte dry volume measurements of both D. tenebrosus and D. copei in the wild and in captivity. No prior studies have evaluated the hematological parameters of Dicamptodon salamanders. My investigation revealed similar leukocyte ratios between species and between wild and captive D. tenebrosus, while leukocyte ratios of wild and captive D. copei were significantly different. Dicamptodon species and populations vary in metamorphic tendencies though the reasons for this variation are not known. In Chapter 3 I investigated the difference in metamorphic tendencies of D. copei and D. tenebrosus. First, I tested the hypotheses that high water inhibits and thermal stress induces metamorphosis. Neither lowered water, nor increased aquatic temperatures induced metamorphosis. Secondly, I compared thermal preferences of both species and found differences in the selection tendencies between species and between sizes of both species. Lastly, I stress responses of both species to 1.66º C, 21.11 º C and 25º C water using a hematological approach. This study revealed significant differences in hematological stress indices between the two species. In Chapter 4, I explored the courtship behaviors of D. copei and D. tenebrosus and characterized each behavior and temporal pattern, using a phyloethological approach. I then compared these courtship behaviors between species and to that of the nearest salamander family, Ambystomatidae. The courtship patterns and behaviors were similar in both species, but they did not resemble the courtship patterns or behaviors of their sister taxon, Ambystoma. Title: Life history variables of Dicamptodon salamanders Author: Wagner, Lisa A. It is good practice to fully understand components of an ecosystem if we hope to preserve its biodiversity. A problem is that we know very little about some organisms and nothing of others. Studies that investigate an organism’s basic biological, ecological and physiological life history variables advance our knowledge of the species of interest and also offer insight about community structure and function. In this thesis I explore courtship behaviors, metamorphic tendencies and hematological parameters in two species of Dicamptodon salamanders (D. copei and D. tenebrosus). Ecologists examine blood to assess hematological responses to a plethora of factors including hormonal changes, parasites, reproductive status and environmental stressors. While hematologic principles are fairly conserved in vertebrates, blood tissue has evolved to match the organism with its environment and there is considerable diversity in hematological parameters across taxa. Therefore, it is necessary to collect species specific baseline data for comparison. In Chapter 2, I quantified relative white blood cells and erythrocyte dry volume measurements of both D. tenebrosus and D. copei in the wild and in captivity. No prior studies have evaluated the hematological parameters of Dicamptodon salamanders. My investigation revealed similar leukocyte ratios between species and between wild and captive D. tenebrosus, while leukocyte ratios of wild and captive D. copei were significantly different. Dicamptodon species and populations vary in metamorphic tendencies though the reasons for this variation are not known. In Chapter 3 I investigated the difference in metamorphic tendencies of D. copei and D. tenebrosus. First, I tested the hypotheses that high water inhibits and thermal stress induces metamorphosis. Neither lowered water, nor increased aquatic temperatures induced metamorphosis. Secondly, I compared thermal preferences of both species and found differences in the selection tendencies between species and between sizes of both species. Lastly, I stress responses of both species to 1.66º C, 21.11 º C and 25º C water using a hematological approach. This study revealed significant differences in hematological stress indices between the two species. In Chapter 4, I explored the courtship behaviors of D. copei and D. tenebrosus and characterized each behavior and temporal pattern, using a phyloethological approach. I then compared these courtship behaviors between species and to that of the nearest salamander family, Ambystomatidae. The courtship patterns and behaviors were similar in both species, but they did not resemble the courtship patterns or behaviors of their sister taxon, Ambystoma. Close

• 152. [Article] Interspecific competition among four species of grain beetles at three temperature and moisture levels

  This study was conducted to test the performance of four species of stored grain beetles in competition at three levels of moisture and temperature. The insects used in these tests were the granary weevil, ...

  Citation × Citation Citation Abstract Copy Title: Interspecific competition among four species of grain beetles at three temperature and moisture levels Author: O'Brien, Joseph Francis This study was conducted to test the performance of four species of stored grain beetles in competition at three levels of moisture and temperature. The insects used in these tests were the granary weevil, the rice weevil, the saw-toothed grain beetle and the red flour beetle. The experiments were conducted at temperatures of 90, 80, and 70 degrees Fahrenheit and at moisture levels of 15, 12, and 9 percent moisture content in two varieties of commercial wheat. Redmond variety commercial feed wheat was used for the majority of these tests. Several of the tests were duplicated using Idaed variety seed wheat. The competition studies were designed to test the performance of one species of grain beetle when reared in the presence of one or two other species. The procedure used was to obtain 50 adult insects of each species from stock cultures. These insects were picked at random and introduced into 250 gram samples of wheat in one pint containers and allowed to remain for one week. The initial adult population was then removed and the adult progeny were counted periodically to determine the size and time of appearance of the first generation. The following combinations of insects were tested: 1. Granary weevil and saw-toothed grain beetle 2. Granary weevil and red flour beetle 3. Saw-toothed grain beetle and red flour beetle 4. Granary weevil, saw-toothed grain beetle and red flour beetle 5. Rice weevil and saw-toothed grain beetle 6. Rice weevil and red flour beetle In addition to these combinations, all species of insects were reared alone in each test in order to compare the performance of the insects when in pure culture and when in competitive situations with the other species. The rice weevil was the best competitor of the four species and was less influenced by the presence of other species of beetles. The rice weevil has a wide range of temperature and moisture tolerance and, though considered a tropical species, it is a common and successful pest of stored grain in the Pacific Northwest. The granary weevil was a good competitor because of its capacity to attack whole grains but did riot do as well as the rice weevil, probably because of its lower reproductive rate and longer life cycle. The granary weevil and the rice weevil were well adjusted to the conditions of these tests because of their ability as primary feeders in whole grain. Competition between weevils and bran bugs (the sawtoothed grain beetle and the red flour beetle) usually favored the bran bugs since the weevils chewed up the grain and made food material available to the bran bugs. In competition with weevils, the bran bugs usually appeared earlier than the former but ordinarily had smaller populations. In competition between bran bugs, the red flour beetle was almost always the dominant species. This was because of the ability of the red flour beetle to attack whole wheat grains and because of its extensive predation of the eggs and pupae of the saw-toothed grain beetle. The saw-toothed grain beetle and the red flour beetle usually produced larger populations in the presence of the rice weevil than when with the granary weevil. Where conditions of high temperature and moisture were present in the grain, mold often formed. The presence of the mold may have been favorable to the two species of bran bugs. It has been observed that when the granary weevil or the rice weevil is reared alone under high moisture conditions, there is considerable mold growth. When, however, the weevils are reared in the presence of one or two species of bran bugs, little or no mold is found. It is not known if the bran buns actually feed ori the mold but the results of these tests indicate that both species of bran bugs either feed on the mold or in some way inhibit its formation in grain at high moisture and. temperature levels. This work was performed as part of regional project WM-16 (maintaining marketability of stored wheat through the control of insects) and was conducted under an assistantship granted by Oregon State College, Department of Entomology, Corvallis, Oregon. Title: Interspecific competition among four species of grain beetles at three temperature and moisture levels Author: O'Brien, Joseph Francis This study was conducted to test the performance of four species of stored grain beetles in competition at three levels of moisture and temperature. The insects used in these tests were the granary weevil, the rice weevil, the saw-toothed grain beetle and the red flour beetle. The experiments were conducted at temperatures of 90, 80, and 70 degrees Fahrenheit and at moisture levels of 15, 12, and 9 percent moisture content in two varieties of commercial wheat. Redmond variety commercial feed wheat was used for the majority of these tests. Several of the tests were duplicated using Idaed variety seed wheat. The competition studies were designed to test the performance of one species of grain beetle when reared in the presence of one or two other species. The procedure used was to obtain 50 adult insects of each species from stock cultures. These insects were picked at random and introduced into 250 gram samples of wheat in one pint containers and allowed to remain for one week. The initial adult population was then removed and the adult progeny were counted periodically to determine the size and time of appearance of the first generation. The following combinations of insects were tested: 1. Granary weevil and saw-toothed grain beetle 2. Granary weevil and red flour beetle 3. Saw-toothed grain beetle and red flour beetle 4. Granary weevil, saw-toothed grain beetle and red flour beetle 5. Rice weevil and saw-toothed grain beetle 6. Rice weevil and red flour beetle In addition to these combinations, all species of insects were reared alone in each test in order to compare the performance of the insects when in pure culture and when in competitive situations with the other species. The rice weevil was the best competitor of the four species and was less influenced by the presence of other species of beetles. The rice weevil has a wide range of temperature and moisture tolerance and, though considered a tropical species, it is a common and successful pest of stored grain in the Pacific Northwest. The granary weevil was a good competitor because of its capacity to attack whole grains but did riot do as well as the rice weevil, probably because of its lower reproductive rate and longer life cycle. The granary weevil and the rice weevil were well adjusted to the conditions of these tests because of their ability as primary feeders in whole grain. Competition between weevils and bran bugs (the sawtoothed grain beetle and the red flour beetle) usually favored the bran bugs since the weevils chewed up the grain and made food material available to the bran bugs. In competition with weevils, the bran bugs usually appeared earlier than the former but ordinarily had smaller populations. In competition between bran bugs, the red flour beetle was almost always the dominant species. This was because of the ability of the red flour beetle to attack whole wheat grains and because of its extensive predation of the eggs and pupae of the saw-toothed grain beetle. The saw-toothed grain beetle and the red flour beetle usually produced larger populations in the presence of the rice weevil than when with the granary weevil. Where conditions of high temperature and moisture were present in the grain, mold often formed. The presence of the mold may have been favorable to the two species of bran bugs. It has been observed that when the granary weevil or the rice weevil is reared alone under high moisture conditions, there is considerable mold growth. When, however, the weevils are reared in the presence of one or two species of bran bugs, little or no mold is found. It is not known if the bran buns actually feed ori the mold but the results of these tests indicate that both species of bran bugs either feed on the mold or in some way inhibit its formation in grain at high moisture and. temperature levels. This work was performed as part of regional project WM-16 (maintaining marketability of stored wheat through the control of insects) and was conducted under an assistantship granted by Oregon State College, Department of Entomology, Corvallis, Oregon. Close

• 153. [Article] Ecology of forest floor bryophytes in Pseudotsuga menziesii-Tsuga heterophylla stands of western Oregon : implications for forest management

  Species richness and abundance of forest floor bryophytes, including epiphytes from incorporated litterfall, were assessed at two sites in western Oregon. Bryophyte diversity, abundance, and community ...

  Citation × Citation Citation Abstract Copy Title: Ecology of forest floor bryophytes in Pseudotsuga menziesii-Tsuga heterophylla stands of western Oregon : implications for forest management Author: Rambo, Thomas Roy Species richness and abundance of forest floor bryophytes, including epiphytes from incorporated litterfall, were assessed at two sites in western Oregon. Bryophyte diversity, abundance, and community composition were compared between sites, and between young forest stands ([approximately] 55 yrs.) and old-growth stands (400+ yrs.) within each site. Relationships of stand structural features to diversity and community composition were assessed by stratifying sampling between "diversity" plots placed in areas of greater structural diversity, such as hardwood openings and remnant old-growth trees, and "matrix" plots situated within the remaining more homogeneous conifer-dominated forest matrix. Bryophyte relationships to substrate and stand age were quantified using the method of Dufrene and Legendre, which combines a species' relative abundance and relative frequency to calculate that species' importance in relation to environmental variables. The resulting "indicator value" describes a species' reliability for indicating the given environmental parameter. Ninety-three bryophyte species were found. Thirty-nine were indicative of either humus, a decay class of coarse woody debris, or stand age. A suite of bryophytes indicated old-growth forest. These were mainly either epiphytes associated with older conifers or liverworts associated with coarse woody debris. Hardwood-associated epiphytes mainly indicated young stands. Richness, particularly for liverworts, was significantly higher in old-growth than young stands, and the two ages differed significantly in community composition Substrate (ground versus coarse woody debris) and overstory (conifers versus hardwoods) were most strongly correlated with variation in bryophyte community composition. Composition changed along the continuum of coarse woody debris decomposition from recently fallen trees with intact bark to forest floor humus. Relatively open hardwood-dominated diversity plots differed in composition from matrix plots. Bryophyte abundance was lower in denser stands and plots, and positively correlated with canopy gaps, percentage of hardwoods, and incident solar radiation. The generality of inferences derived from results is limited by the number of stands studied. Landscape level factors such as topography and prevailing slope and aspect may influence results between sites and ages. However, results suggest that 1) availability of light may limit bryophyte productivity in these stands, 2) bryophyte richness increases with stand continuity, 3) older conifers, hardwoods, and coarse woody debris foster habitat complexity and diversity of bryophytes, and 4) diversity of forest floor bryophytes will be enhanced when a full range of coarse woody debris decay classes is present. Implementation of strategies to protect these biological legacies when thinning managed stands is consistent with an ecosystem approach to forest management. Title: Ecology of forest floor bryophytes in Pseudotsuga menziesii-Tsuga heterophylla stands of western Oregon : implications for forest management Author: Rambo, Thomas Roy Species richness and abundance of forest floor bryophytes, including epiphytes from incorporated litterfall, were assessed at two sites in western Oregon. Bryophyte diversity, abundance, and community composition were compared between sites, and between young forest stands ([approximately] 55 yrs.) and old-growth stands (400+ yrs.) within each site. Relationships of stand structural features to diversity and community composition were assessed by stratifying sampling between "diversity" plots placed in areas of greater structural diversity, such as hardwood openings and remnant old-growth trees, and "matrix" plots situated within the remaining more homogeneous conifer-dominated forest matrix. Bryophyte relationships to substrate and stand age were quantified using the method of Dufrene and Legendre, which combines a species' relative abundance and relative frequency to calculate that species' importance in relation to environmental variables. The resulting "indicator value" describes a species' reliability for indicating the given environmental parameter. Ninety-three bryophyte species were found. Thirty-nine were indicative of either humus, a decay class of coarse woody debris, or stand age. A suite of bryophytes indicated old-growth forest. These were mainly either epiphytes associated with older conifers or liverworts associated with coarse woody debris. Hardwood-associated epiphytes mainly indicated young stands. Richness, particularly for liverworts, was significantly higher in old-growth than young stands, and the two ages differed significantly in community composition Substrate (ground versus coarse woody debris) and overstory (conifers versus hardwoods) were most strongly correlated with variation in bryophyte community composition. Composition changed along the continuum of coarse woody debris decomposition from recently fallen trees with intact bark to forest floor humus. Relatively open hardwood-dominated diversity plots differed in composition from matrix plots. Bryophyte abundance was lower in denser stands and plots, and positively correlated with canopy gaps, percentage of hardwoods, and incident solar radiation. The generality of inferences derived from results is limited by the number of stands studied. Landscape level factors such as topography and prevailing slope and aspect may influence results between sites and ages. However, results suggest that 1) availability of light may limit bryophyte productivity in these stands, 2) bryophyte richness increases with stand continuity, 3) older conifers, hardwoods, and coarse woody debris foster habitat complexity and diversity of bryophytes, and 4) diversity of forest floor bryophytes will be enhanced when a full range of coarse woody debris decay classes is present. Implementation of strategies to protect these biological legacies when thinning managed stands is consistent with an ecosystem approach to forest management. Close

• 154. [Article] Lichen traits and species as indicators of vegetation and environment

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

  Citation × Citation Citation Abstract Copy Title: Lichen traits and species as indicators of vegetation and environment Author: Swanson, David K., McCune, Bruce, Nelson, Peter R. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by American Bryological and Lichenological Society and can be found at: http://www.bioone.org/loi/bryo Title: Lichen traits and species as indicators of vegetation and environment Author: Swanson, David K., McCune, Bruce, Nelson, Peter R. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by American Bryological and Lichenological Society and can be found at: http://www.bioone.org/loi/bryo Close

• 155. [Article] Studies to facilitate reintroduction of golden paintbrush (Castilleja levisecta) to the Willamette Valley, Oregon

  Golden paintbrush (Castilleja levisecta Greenman) historically inhabited the prairies of the Willamette Valley, Oregon. However, this Pacific Northwest endemic is currently restricted to eleven sites in ...

  Citation × Citation Citation Abstract Copy Title: Studies to facilitate reintroduction of golden paintbrush (Castilleja levisecta) to the Willamette Valley, Oregon Author: Lawrence, Beth A. Golden paintbrush (Castilleja levisecta Greenman) historically inhabited the prairies of the Willamette Valley, Oregon. However, this Pacific Northwest endemic is currently restricted to eleven sites in the Puget Trough of Washington and British Columbia. Recovery criteria call for the establishment of new populations throughout the species historic range, including the Willamette Valley. In order to facilitate reintroduction to this region, we examined: (1) habitat characteristics of potential C. levisecta recovery sites in the Willamette Valley and compared them to remaining populations in the Puget Trough, (2) a suite of ecological and genetic factors likely to contribute to reintroduction success using common garden experiments, and (3) how the performance of this rare hemiparasite was affected by the availability of different host combinations in the greenhouse and in the field. Potential C. levisecta reintroduction sites in the Willamette Valley had distinct vegetation communities and soil characteristics compared with remaining populations in the Puget Trough. This disparity was likely related to regional differences in geology, climate, ocean proximity, and land-use history. Many of the species indicative of remaining populations in the Puget Trough were native pereimials, while those of potential reintroduction sites in the Willamette Valley were introduced annuals. Soil characteristics of C. levisecta sites were also distinct among the two ecoregions. Puget Trough sites were located on sandy soils with generally high levels of magnesium and sulfur, while Willamette Valley sites were found on silty-clay soils with high concentrations of potassium and phosphorous. Differences in soil texture, and magnesium and potassium concentrations were associated with plant community divergence among the two regions. Decisions regarding seed source and recovery site selection are especially difficult in portions of a species range that are uninhabited, as no reference populations exist with which to compare ecological information. Using common garden experiments, we tested hypotheses about how C. levisecta transplants would perform in relation to the ecological similarity between seed source and introduction site, the effective population size and genetic diversity of seed sources, and the habitat quality of the recovery site. We observed significant variation in performance measures among source populations and common garden sites. Plant community characteristics, including the abundance of nonnative species and the similarity in community structure between source populations and common garden sites, helped explain the variation in these performance measures. Exotic species cover at common garden sites was associated with a reduction in performance of first year C. levisecta transplants. Survival of second year transplants increased with increasing similarity in plant functional groups between source and common garden sites, supporting the idea of a "home-habitat advantage." These results indicate that high quality prairies, dominated by native perennial species with low nonnative abundance, should be targeted for recovery sites. We recommend using plant material from Whidbey Island, WA, whose three populations represented in our study consistently performed well. Rare, parasitic plants pose an interesting challenge to restoration practitioners. We examined how the performance of C. levisecta was affected by the availability of different host combinations in the greenhouse and in the field. Castilleja levisecta individuals were grown with two grass individuals (Festuca roemeri; Poaceae), two non-grass hosts (Eriophyllum lanatum; Asteraceae), one individual of each of these species, or without a host. Our greenhouse results provide little support for the complimentary diet hypothesis, which states that parasites grown with multiple host species perform better than individuals grown alone or with a single host. Castilleja levisecta individuals grown with two different species performed better than those co-planted only with F. roemeri, but did not differ from E. lanatum or no-host treatments. In the field, vole activity had indirect effects on C. levisecta survival mediated through host species. Vole tunneling and C. levisecta mortality were strongly associated with host treatments including E. lanatum. Field survival was significantly higher among no-host C. levisecta individuals than those grown with E. lanatum or mixed host treatments. We do not suggest coplanting C. levisecta with E. lanatum in the field. Although no-host C. levisecta individuals had the greatest first year field survival, we suspect that perennial host plants will be beneficial to future survival. Therefore, we recommend planting C. levisecta in the Willamette Valley, OR with F. roemeri. Title: Studies to facilitate reintroduction of golden paintbrush (Castilleja levisecta) to the Willamette Valley, Oregon Author: Lawrence, Beth A. Golden paintbrush (Castilleja levisecta Greenman) historically inhabited the prairies of the Willamette Valley, Oregon. However, this Pacific Northwest endemic is currently restricted to eleven sites in the Puget Trough of Washington and British Columbia. Recovery criteria call for the establishment of new populations throughout the species historic range, including the Willamette Valley. In order to facilitate reintroduction to this region, we examined: (1) habitat characteristics of potential C. levisecta recovery sites in the Willamette Valley and compared them to remaining populations in the Puget Trough, (2) a suite of ecological and genetic factors likely to contribute to reintroduction success using common garden experiments, and (3) how the performance of this rare hemiparasite was affected by the availability of different host combinations in the greenhouse and in the field. Potential C. levisecta reintroduction sites in the Willamette Valley had distinct vegetation communities and soil characteristics compared with remaining populations in the Puget Trough. This disparity was likely related to regional differences in geology, climate, ocean proximity, and land-use history. Many of the species indicative of remaining populations in the Puget Trough were native pereimials, while those of potential reintroduction sites in the Willamette Valley were introduced annuals. Soil characteristics of C. levisecta sites were also distinct among the two ecoregions. Puget Trough sites were located on sandy soils with generally high levels of magnesium and sulfur, while Willamette Valley sites were found on silty-clay soils with high concentrations of potassium and phosphorous. Differences in soil texture, and magnesium and potassium concentrations were associated with plant community divergence among the two regions. Decisions regarding seed source and recovery site selection are especially difficult in portions of a species range that are uninhabited, as no reference populations exist with which to compare ecological information. Using common garden experiments, we tested hypotheses about how C. levisecta transplants would perform in relation to the ecological similarity between seed source and introduction site, the effective population size and genetic diversity of seed sources, and the habitat quality of the recovery site. We observed significant variation in performance measures among source populations and common garden sites. Plant community characteristics, including the abundance of nonnative species and the similarity in community structure between source populations and common garden sites, helped explain the variation in these performance measures. Exotic species cover at common garden sites was associated with a reduction in performance of first year C. levisecta transplants. Survival of second year transplants increased with increasing similarity in plant functional groups between source and common garden sites, supporting the idea of a "home-habitat advantage." These results indicate that high quality prairies, dominated by native perennial species with low nonnative abundance, should be targeted for recovery sites. We recommend using plant material from Whidbey Island, WA, whose three populations represented in our study consistently performed well. Rare, parasitic plants pose an interesting challenge to restoration practitioners. We examined how the performance of C. levisecta was affected by the availability of different host combinations in the greenhouse and in the field. Castilleja levisecta individuals were grown with two grass individuals (Festuca roemeri; Poaceae), two non-grass hosts (Eriophyllum lanatum; Asteraceae), one individual of each of these species, or without a host. Our greenhouse results provide little support for the complimentary diet hypothesis, which states that parasites grown with multiple host species perform better than individuals grown alone or with a single host. Castilleja levisecta individuals grown with two different species performed better than those co-planted only with F. roemeri, but did not differ from E. lanatum or no-host treatments. In the field, vole activity had indirect effects on C. levisecta survival mediated through host species. Vole tunneling and C. levisecta mortality were strongly associated with host treatments including E. lanatum. Field survival was significantly higher among no-host C. levisecta individuals than those grown with E. lanatum or mixed host treatments. We do not suggest coplanting C. levisecta with E. lanatum in the field. Although no-host C. levisecta individuals had the greatest first year field survival, we suspect that perennial host plants will be beneficial to future survival. Therefore, we recommend planting C. levisecta in the Willamette Valley, OR with F. roemeri. Close

• 156. [Article] Effects of fire on seedling establishment in upland prairies in the Willamette Valley, Oregon

  Prior to European settlement, native prairie dominated the landscape of the Willamette Valley. Today, due to urbanization, agriculture, and the cessation of burning, only isolated remnants of these grasslands ...

  Citation × Citation Citation Abstract Copy Title: Effects of fire on seedling establishment in upland prairies in the Willamette Valley, Oregon Author: Maret, Mary P. Prior to European settlement, native prairie dominated the landscape of the Willamette Valley. Today, due to urbanization, agriculture, and the cessation of burning, only isolated remnants of these grasslands still exist. In response to conservation concerns, there has been a move to restore the remaining prairies in the Willamette Valley, and prescribed burning and sowing native seed are often top candidates for grassland restoration. However, the effects of burning on native seedling establishment and the spread of weedy exotics are largely unknown. In this study, I investigated how prescribed burning affects native and exotic species seedling establishment on three upland prairie vegetation types in the Willamette Valley. The general approach was to sow a known number of seeds from several native and exotic grassland species into experimentally manipulated plots, designed to separate the effects of litter removal from the other effects of burning, and to monitor seedling densities. Germinability and dormancy characteristics of the sowed seeds were also addressed. An additional study focused on the fire temperatures at soil surface in three grassland vegetation types and two burn sizes. Burning increased the establishment of most or all of the sown native species in the two low quality, exotic grass sites. Exotic seedling establishment also tended to increase, but did not differ significantly from unburned plots for most species tested. On the higher quality, native bunchgrass site, burning did not significantly improve native species establishment, but did significantly increase the establishment of short-lived exotic species over those in unburned plots. The germination and dormancy characteristics of the native and exotic species tested indicate that grasses, both native and exotic, are more likely than forbs to be non-dormant in the autumn following dispersal. Forbs, especially native forbs tend to require cold-stratification for maximum germinability. During grassland fire, temperatures at soil surface were relatively cool. Fire temperature intensity was highest in the higher quality native bunchgrass vegetation. These burns reached higher temperatures significantly closer to the soil surface than the plot burns in lower quality sites dominated by annual or perennial exotic grasses. Average temperatures in a two hectare broadcast burn and in replicated 2m x 2.5m plot bums in an annual exotic grassland were very similar. Prescribed burning can be an excellent tool for the restoration of low-quality upland prairies when combined with sowing native seeds in the fall. However, on high-quality prairie, prescribed burning may be a poor restoration choice for promoting native seedlings, as burning promoted weedy species without enhancing native seedling establishment. Title: Effects of fire on seedling establishment in upland prairies in the Willamette Valley, Oregon Author: Maret, Mary P. Prior to European settlement, native prairie dominated the landscape of the Willamette Valley. Today, due to urbanization, agriculture, and the cessation of burning, only isolated remnants of these grasslands still exist. In response to conservation concerns, there has been a move to restore the remaining prairies in the Willamette Valley, and prescribed burning and sowing native seed are often top candidates for grassland restoration. However, the effects of burning on native seedling establishment and the spread of weedy exotics are largely unknown. In this study, I investigated how prescribed burning affects native and exotic species seedling establishment on three upland prairie vegetation types in the Willamette Valley. The general approach was to sow a known number of seeds from several native and exotic grassland species into experimentally manipulated plots, designed to separate the effects of litter removal from the other effects of burning, and to monitor seedling densities. Germinability and dormancy characteristics of the sowed seeds were also addressed. An additional study focused on the fire temperatures at soil surface in three grassland vegetation types and two burn sizes. Burning increased the establishment of most or all of the sown native species in the two low quality, exotic grass sites. Exotic seedling establishment also tended to increase, but did not differ significantly from unburned plots for most species tested. On the higher quality, native bunchgrass site, burning did not significantly improve native species establishment, but did significantly increase the establishment of short-lived exotic species over those in unburned plots. The germination and dormancy characteristics of the native and exotic species tested indicate that grasses, both native and exotic, are more likely than forbs to be non-dormant in the autumn following dispersal. Forbs, especially native forbs tend to require cold-stratification for maximum germinability. During grassland fire, temperatures at soil surface were relatively cool. Fire temperature intensity was highest in the higher quality native bunchgrass vegetation. These burns reached higher temperatures significantly closer to the soil surface than the plot burns in lower quality sites dominated by annual or perennial exotic grasses. Average temperatures in a two hectare broadcast burn and in replicated 2m x 2.5m plot bums in an annual exotic grassland were very similar. Prescribed burning can be an excellent tool for the restoration of low-quality upland prairies when combined with sowing native seeds in the fall. However, on high-quality prairie, prescribed burning may be a poor restoration choice for promoting native seedlings, as burning promoted weedy species without enhancing native seedling establishment. Close

• 157. [Article] Riparian and adjacent upslope beetle communities along a third order stream in the western Cascade Mountain Range, Oregon

  Monitoring wildlife habitats has become important to forest ecosystem management because it provides valuable information about the response of forests and their species to harvest practices, impacts from ...

  Citation × Citation Citation Abstract Copy Title: Riparian and adjacent upslope beetle communities along a third order stream in the western Cascade Mountain Range, Oregon Author: Brenner, Gregory John Monitoring wildlife habitats has become important to forest ecosystem management because it provides valuable information about the response of forests and their species to harvest practices, impacts from recreational use, conservation efforts, and natural and human-caused disturbances. Monitoring is a complex task that requires a variety of abiotic and biotic measurements and decisions about what should be measured, and when and where measurements should be taken. Riparian habitats contain unusually high diversity and are important to land managers. Wildlife assessments of riparian areas have focused on vertebrate species such as amphibians, birds, and mammals, but have largely ignored the arthropod components of the habitats. Arthropods constitute over 85% of all species and posses characteristics that make them valuable for tracking environmental changes. The purpose of this study was to gather site-specific data about epigaeic, riparian beetle community composition of the H.J. Andrews Experimental Forest (HJA). The patterns of beetle distribution, abundance, and diversity were analyzed and the results were used to characterize and compare the riparian and adjacent upslope beetle communities. Almost 8,000 beetle specimens representing about 250 species were collected from 141 pitfall traps placed along 10 transects in 3 different channel morphologies along Lookout Creek in the HJA. Traps were opened during six 30-day sampling periods over 2 years. Riparian and adjacent upslope beetle communities had high diversity measurements. The average difference of the calculated Simpson's Diversity Index between the two communities was 0.0116 and represented about 1% of the average riparian diversity. Analysis of species-curves indicated that the riparian habitats contained a higher total number of species. Multivariate Principal Coordinate Analysis indicated that the two habitats had distinctly different beetle communities. Multigroup Discriminant Analysis correctly classified 89.7% of the sampling units as the habitat group into which they were assigned a priori. Detailed recommendations for monitoring riparian habitats were discussed. Title: Riparian and adjacent upslope beetle communities along a third order stream in the western Cascade Mountain Range, Oregon Author: Brenner, Gregory John Monitoring wildlife habitats has become important to forest ecosystem management because it provides valuable information about the response of forests and their species to harvest practices, impacts from recreational use, conservation efforts, and natural and human-caused disturbances. Monitoring is a complex task that requires a variety of abiotic and biotic measurements and decisions about what should be measured, and when and where measurements should be taken. Riparian habitats contain unusually high diversity and are important to land managers. Wildlife assessments of riparian areas have focused on vertebrate species such as amphibians, birds, and mammals, but have largely ignored the arthropod components of the habitats. Arthropods constitute over 85% of all species and posses characteristics that make them valuable for tracking environmental changes. The purpose of this study was to gather site-specific data about epigaeic, riparian beetle community composition of the H.J. Andrews Experimental Forest (HJA). The patterns of beetle distribution, abundance, and diversity were analyzed and the results were used to characterize and compare the riparian and adjacent upslope beetle communities. Almost 8,000 beetle specimens representing about 250 species were collected from 141 pitfall traps placed along 10 transects in 3 different channel morphologies along Lookout Creek in the HJA. Traps were opened during six 30-day sampling periods over 2 years. Riparian and adjacent upslope beetle communities had high diversity measurements. The average difference of the calculated Simpson's Diversity Index between the two communities was 0.0116 and represented about 1% of the average riparian diversity. Analysis of species-curves indicated that the riparian habitats contained a higher total number of species. Multivariate Principal Coordinate Analysis indicated that the two habitats had distinctly different beetle communities. Multigroup Discriminant Analysis correctly classified 89.7% of the sampling units as the habitat group into which they were assigned a priori. Detailed recommendations for monitoring riparian habitats were discussed. Close

• 158. [Article] Biotic soil crusts of Oregon's shrub steppe

  This research examines the community composition of biotic soil crusts at nine sites in central and eastern Oregon, U.S.A. At each site, data were collected in one pair of livestock-grazed and excluded ...

  Citation × Citation Citation Abstract Copy Title: Biotic soil crusts of Oregon's shrub steppe Author: Ponzetti, Jeanne M. This research examines the community composition of biotic soil crusts at nine sites in central and eastern Oregon, U.S.A. At each site, data were collected in one pair of livestock-grazed and excluded transects. Variables recorded included: cover of biotic soil crusts and vascular plant species, soil surface pH, electrical conductivity, soil surface roughness, surface rock, gravel, bare ground, organic litter, and cowpies. Using Non-metric Multidimensional Scaling, we extracted the primary environmental gradients controlling biotic crust community composition among sites. The strongest gradient was related to soil chemistry. Total crust cover, lichen cover, and bryophyte cover were inversely related to soil pH, electrical conductivity, and CIV (Calcareous Index Value; site scores on a scale representing relative soil calcium carbonate content). Total crust cover was also positively associated with temperature, and inversely related to elevation. Biotic crust composition was related to moisture and aspect; cooler, north-facing slopes with greater precipitation and Festuca idahoensis cover were compositionally distinct from flat sites with greater heat exposure. The weakest pattern in these data appears to represent a disturbance gradient, with bare ground inversely related to exclosure age. Transect scores on this gradient were different between currently grazed and exclosure transects ( p = 0.01, blocked MRPP). On average, bare ground was greater in the grazed transects, while total crust cover, cover of nitrogen-fixing lichens, biotic soil surface roughness, and species richness were greater within the exclosures (p 5 0.02 for all, two-tailed paired t-tests). Differences in vascular plant cover, richness, and composition were not detected. CIV was one of the strongest variables related to biotic crust composition. CIV is based on a calcareous index that uses the presence of certain lichen species as indicators of calcareous soils. Using weighted averaging and the abundances of these indicators in our data, we revised this index, incorporating new indicators and removing poor ones. We conclude that 1) biotic soil crusts are sensitive indicators of disturbance, 2) there are strong compositional differences in shrub steppe crust communities of Oregon, which are related to regional soil and climate differences, and 3) lichens can be used as sensitive indicators of soil chemistry. Title: Biotic soil crusts of Oregon's shrub steppe Author: Ponzetti, Jeanne M. This research examines the community composition of biotic soil crusts at nine sites in central and eastern Oregon, U.S.A. At each site, data were collected in one pair of livestock-grazed and excluded transects. Variables recorded included: cover of biotic soil crusts and vascular plant species, soil surface pH, electrical conductivity, soil surface roughness, surface rock, gravel, bare ground, organic litter, and cowpies. Using Non-metric Multidimensional Scaling, we extracted the primary environmental gradients controlling biotic crust community composition among sites. The strongest gradient was related to soil chemistry. Total crust cover, lichen cover, and bryophyte cover were inversely related to soil pH, electrical conductivity, and CIV (Calcareous Index Value; site scores on a scale representing relative soil calcium carbonate content). Total crust cover was also positively associated with temperature, and inversely related to elevation. Biotic crust composition was related to moisture and aspect; cooler, north-facing slopes with greater precipitation and Festuca idahoensis cover were compositionally distinct from flat sites with greater heat exposure. The weakest pattern in these data appears to represent a disturbance gradient, with bare ground inversely related to exclosure age. Transect scores on this gradient were different between currently grazed and exclosure transects ( p = 0.01, blocked MRPP). On average, bare ground was greater in the grazed transects, while total crust cover, cover of nitrogen-fixing lichens, biotic soil surface roughness, and species richness were greater within the exclosures (p 5 0.02 for all, two-tailed paired t-tests). Differences in vascular plant cover, richness, and composition were not detected. CIV was one of the strongest variables related to biotic crust composition. CIV is based on a calcareous index that uses the presence of certain lichen species as indicators of calcareous soils. Using weighted averaging and the abundances of these indicators in our data, we revised this index, incorporating new indicators and removing poor ones. We conclude that 1) biotic soil crusts are sensitive indicators of disturbance, 2) there are strong compositional differences in shrub steppe crust communities of Oregon, which are related to regional soil and climate differences, and 3) lichens can be used as sensitive indicators of soil chemistry. Close

• 159. [Article] Ecological effects of spring and fall prescribed burning on basin big sagebrush : Idaho fescue--bluebunch wheatgrass communities

  The vegetation response of spring and fall prescribed fires in basin big sagebrush (Artemisia tridentata subsp. tridentata Nutt.)/Idaho fescue (Festuca idahoensis Elmer)--bluebunch wheatgrass (Agropyron ...

  Citation × Citation Citation Abstract Copy Title: Ecological effects of spring and fall prescribed burning on basin big sagebrush : Idaho fescue--bluebunch wheatgrass communities Author: Sapsis, David B. The vegetation response of spring and fall prescribed fires in basin big sagebrush (Artemisia tridentata subsp. tridentata Nutt.)/Idaho fescue (Festuca idahoensis Elmer)--bluebunch wheatgrass (Agropyron spicatum Pursh. (Scribn. & Smith)) communities was measured at the John Day Fossil Beds National Monument in eastern Oregon. Objectives of the study were to quantify fuel loads, environmental conditions, fire behavior and vegetation response corresponding to these two fire treatments. Pretreatment fuel loads in the experimental units ranged from 5 to 12 Mg/ha, with the fall treatment units averaging 10.5 Mg/ha, and the spring units averaging 6.2 Mg/ha. Both treatments contained large amounts (> 3 Mg/ha) of herbaceous fuels. Moisture content of grass and herb fuels were significantly greater in the spring burned units. This is believed to be largely responsible for the less severe fire behavior observed in the spring burn treatment. Flame lengths averaged 4.2 m in fall burns, compared to a mean of 1.7 m in the spring plots. Similarly, rate of spread was significantly greater in the fall units, averaging 1.6 m/s, compared to 0.2 m/s in the spring treatment. Fireline Intensity was seven times greater, and total energy release was twice was great in the fall burns. Neither burn treatment resulted in significant mortality of bluebunch wheatgrass, but fall burning did cause significant mortality of Idaho fescue, where 20% of the population was killed. Fall burning stimulated tillering of bluebunch wheatgrass, as the average basal area increased both one and two years following burning. Average basal area per plant of Idaho fescue was reduced by 23% the first year following fall burning; however plants recovered to 90% of their preburn size by the second post-fire year. Spring burning resulted in no significant change in basal area of either species. Fall burning significantly reduced the number of flowering culms on bluebunch wheatgrass plants the first post-fire year (from 36 to 12 per plant); however, by the second post-fire year, number of flowering culms was significantly greater than either pre-burn or control levels (59/plant). Similarly, fall burning of Idaho fescue averaged 60% more flowering culms per plant as adjacent controls (11 compared to 7/plant). Spring burning reduced flowering of both species the first year following burning. Both burn treatments reduced the frequency of annual grasses, while causing no change in frequency of perennial grasses. Annual forbs increased in abundance following both burn treatments. Fire resulted in replacement of exotic annual grasses with annual forb species. Dominant perennial forbs responded variably in both burn treatments, as well as control plots. Frequency of sagebrush increased significantly in both spring and control experimental units in 1989 (one year after spring burning), while fall burns (two years posttreatment) demonstrated no such increase. Apparently, factors relating to the greater fire severity (e.g. consumption, total energy) in the fall burns reduced the rate and degree of reinvasion by sagebrush in the fall burn plots. Densities of annual grasses and woody species were significantly reduced by both burn treatments. Cheatgrass (Bromus tectorum L.) density before burning averaged 446 and 552/m2 in fall and spring units, respectively, as compared to 10 and 85/m2, respectively, the first post-fire year. Big sagebrush was completely eliminated by the fall fire, while spring burning resulted in an 84% decrease in density. Density of western juniper (Juniperus occidentalls Hook.) was reduced 100% by both burn treatments. Species diversity, as measured by the Shannon-Weaver Index (H'), was reduced by fall burning from 2.69 before treatment to 2.53 the first year following burning , but increased to 2.81 second post-fire year. Control plots behaved similarly, although changes were not as great. Changes were most evident in terms of rare species, many of which were not present prior to burning. Spring burning resulted in an no change in species diversity the first year after burning, although, species richness increased from 34 to 41. Both burn treatments appeared effective at changing stand structure to that of a dominance by native perrenial grasses and forbs. The reduced competition from woody plants has, and presumably will continue to favor surviving herbaceous plants. Overall fire effects appear to fit into land management policy of the National Park Service in regard to maintaining wildlands in a pristine state. Specifically, both spring and fall burning reduced fuel hazard, and increased the relative abundance of native species, indicating that prescribed burning may be an effective land management tool for the National Park Service and others managing similar rangelands. Title: Ecological effects of spring and fall prescribed burning on basin big sagebrush : Idaho fescue--bluebunch wheatgrass communities Author: Sapsis, David B. The vegetation response of spring and fall prescribed fires in basin big sagebrush (Artemisia tridentata subsp. tridentata Nutt.)/Idaho fescue (Festuca idahoensis Elmer)--bluebunch wheatgrass (Agropyron spicatum Pursh. (Scribn. & Smith)) communities was measured at the John Day Fossil Beds National Monument in eastern Oregon. Objectives of the study were to quantify fuel loads, environmental conditions, fire behavior and vegetation response corresponding to these two fire treatments. Pretreatment fuel loads in the experimental units ranged from 5 to 12 Mg/ha, with the fall treatment units averaging 10.5 Mg/ha, and the spring units averaging 6.2 Mg/ha. Both treatments contained large amounts (> 3 Mg/ha) of herbaceous fuels. Moisture content of grass and herb fuels were significantly greater in the spring burned units. This is believed to be largely responsible for the less severe fire behavior observed in the spring burn treatment. Flame lengths averaged 4.2 m in fall burns, compared to a mean of 1.7 m in the spring plots. Similarly, rate of spread was significantly greater in the fall units, averaging 1.6 m/s, compared to 0.2 m/s in the spring treatment. Fireline Intensity was seven times greater, and total energy release was twice was great in the fall burns. Neither burn treatment resulted in significant mortality of bluebunch wheatgrass, but fall burning did cause significant mortality of Idaho fescue, where 20% of the population was killed. Fall burning stimulated tillering of bluebunch wheatgrass, as the average basal area increased both one and two years following burning. Average basal area per plant of Idaho fescue was reduced by 23% the first year following fall burning; however plants recovered to 90% of their preburn size by the second post-fire year. Spring burning resulted in no significant change in basal area of either species. Fall burning significantly reduced the number of flowering culms on bluebunch wheatgrass plants the first post-fire year (from 36 to 12 per plant); however, by the second post-fire year, number of flowering culms was significantly greater than either pre-burn or control levels (59/plant). Similarly, fall burning of Idaho fescue averaged 60% more flowering culms per plant as adjacent controls (11 compared to 7/plant). Spring burning reduced flowering of both species the first year following burning. Both burn treatments reduced the frequency of annual grasses, while causing no change in frequency of perennial grasses. Annual forbs increased in abundance following both burn treatments. Fire resulted in replacement of exotic annual grasses with annual forb species. Dominant perennial forbs responded variably in both burn treatments, as well as control plots. Frequency of sagebrush increased significantly in both spring and control experimental units in 1989 (one year after spring burning), while fall burns (two years posttreatment) demonstrated no such increase. Apparently, factors relating to the greater fire severity (e.g. consumption, total energy) in the fall burns reduced the rate and degree of reinvasion by sagebrush in the fall burn plots. Densities of annual grasses and woody species were significantly reduced by both burn treatments. Cheatgrass (Bromus tectorum L.) density before burning averaged 446 and 552/m2 in fall and spring units, respectively, as compared to 10 and 85/m2, respectively, the first post-fire year. Big sagebrush was completely eliminated by the fall fire, while spring burning resulted in an 84% decrease in density. Density of western juniper (Juniperus occidentalls Hook.) was reduced 100% by both burn treatments. Species diversity, as measured by the Shannon-Weaver Index (H'), was reduced by fall burning from 2.69 before treatment to 2.53 the first year following burning , but increased to 2.81 second post-fire year. Control plots behaved similarly, although changes were not as great. Changes were most evident in terms of rare species, many of which were not present prior to burning. Spring burning resulted in an no change in species diversity the first year after burning, although, species richness increased from 34 to 41. Both burn treatments appeared effective at changing stand structure to that of a dominance by native perrenial grasses and forbs. The reduced competition from woody plants has, and presumably will continue to favor surviving herbaceous plants. Overall fire effects appear to fit into land management policy of the National Park Service in regard to maintaining wildlands in a pristine state. Specifically, both spring and fall burning reduced fuel hazard, and increased the relative abundance of native species, indicating that prescribed burning may be an effective land management tool for the National Park Service and others managing similar rangelands. Close

• 160. [Article] Quantifying Avian Predation on Fish Populations: Integrating Predator-Specific Deposition Probabilities in Tag Recovery Studies

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

  Citation × Citation Citation Abstract Copy Title: Quantifying Avian Predation on Fish Populations: Integrating Predator-Specific Deposition Probabilities in Tag Recovery Studies Author: Evans, Allen F., Roby, Daniel D., Cramer, Bradley M., Lyons, Donald E., Hostetter, Nathan J., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Taylor & Francis and can be found at: http://www.tandfonline.com/loi/utaf20#.VVYI7UZSVAM. Title: Quantifying Avian Predation on Fish Populations: Integrating Predator-Specific Deposition Probabilities in Tag Recovery Studies Author: Evans, Allen F., Roby, Daniel D., Cramer, Bradley M., Lyons, Donald E., Hostetter, Nathan J., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Taylor & Francis and can be found at: http://www.tandfonline.com/loi/utaf20#.VVYI7UZSVAM. Close