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• 3171. [Article] Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion

  The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity ...

  Citation × Citation Citation Abstract Copy Title: Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion Author: Thompson, Jonathan R. The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity of conditions through which it burned provided an opportunity to analyze the correlates of burn severity across vegetation types and disturbance histories and to describe the weather, topographical, and fuel conditions that gave rise to the mosaic of crown damage. In chapter two, I focused on a region that had burned previously by the 1987 Silver Fire then was subject, in part, to salvage-logging and conifer planting before being reburned by the Biscuit Fire. I used the Landsat-based differenced normalized burn ratio (dNBR) to quantify severity in both fires and took a hypothesis-testing approach to answering two questions: First, was severity in the Biscuit Fire associated with severity in the Silver Fire in unmanaged areas? And second, did areas that were salvaged-logged and planted with conifers after the Silver Fire burn more or less severely in the Biscuit Fire than comparable unmanaged areas? I found that areas that burned severely in 1987 tended to re-burn at high severity in 2002, after controlling for the influence of several topographical and biophysical covariates. Areas unaffected by the initial fire tended to burn at the lowest severities in 2002. In addition, areas that were salvage-logged and planted after the initial fire burned more severely than comparable unmanaged areas, suggesting that post-fire logging and planting did not reduce future fire severity as had been suggested by some. In chapter three, I again focused on the twice-burned landscape, but this time I used a temporal sequence of digital aerial photography plots (6.25 ha) to measure changes in shrub-stratum, hardwood, and conifer cover. I estimated the strength and nature of relationships between crown damage and several fuel, topographical, weather, and management variables. Median crown damage, including damage to the shrub-stratum, on unmanaged plots was 63% after the Biscuit Fire and was most strongly related to damage in the Silver Fire. Plots that burned severely in the Silver Fire and had succeeded to a mix of shrubs and tree regeneration experienced high levels of Biscuit Fire damage. Plots dominated by large conifer cover after the Silver Fire had the lowest levels of Biscuit Fire canopy damage. Median crown damage was 39% for conifer cover and 85% for hardwood cover, and was most strongly related to daily average temperature and "burn period," an index of fire weather and fire suppression effort. Damage in the tree-stratum was largely independent of Silver Fire severity. Plots that had experienced stand replacing fire in 1987 and then were logged and planted with conifers had median crown damage of 100%. Plots that experienced a stand replacing fire but were unmanaged had median crown damage of 95%. The managed areas were at higher topographical positions and had greater total pre-fire cover, which may explain the small difference. These results suggest that in productive, fire-prone landscapes, the patch mosaic of young regenerating forest created by mixed-severity fire can structure the severity pattern of future wildfires occurring at short intervals and support the previous studies findings that post-fire logging and planting did not reduce fire severity. In Chapter four, I expanded my focus to include the entire region burned by the Biscuit Fire and again used digital aerial photos taken before and after the fire to interpret patterns of crown damage and relate them to several fuel, topographical, weather, and management variables. Ninety-eight percent of plots experienced some level of crown damage, but only 10% experienced complete crown damage. The median level of crown damage on unmanaged plots was 74%. Median conifer damage was 52%. The most important predictors of total crown damage were the percentage of pre-fire shrub-stratum vegetation cover and average daily temperature. The most important predictors of conifer damage were average daily temperature and burn period. Increasing levels of shrub-stratum cover were associated with increasing levels of conifer damage and hardwood damage. Large conifers had 32% median crown damage while small conifers had 62% median crown damage. Owing largely to widespread shrub-stratum cover, low-productivity ultramafic soils had 92% median crown damage compared to 59% on non-ultramafic sites. Patterns of damage were similar within the area that burned previously in the 1987 Silver Fire and edaphically comparable areas without a recently history of fire. Median crown damage in conifer plantations was 89% and plantation age was, by far, the most important predictor of the level of damage. Plantations under 20 years old experienced the highest rates of damage. I conclude that weather and vegetation conditions--not topography--were the primary determinants of Biscuit Fire crown damage. These findings suggest that in productive fire-prone ecosystems, fuel treatments that open tree canopies and stimulate shrub-stratum development may be counterproductive. Title: Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion Author: Thompson, Jonathan R. The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity of conditions through which it burned provided an opportunity to analyze the correlates of burn severity across vegetation types and disturbance histories and to describe the weather, topographical, and fuel conditions that gave rise to the mosaic of crown damage. In chapter two, I focused on a region that had burned previously by the 1987 Silver Fire then was subject, in part, to salvage-logging and conifer planting before being reburned by the Biscuit Fire. I used the Landsat-based differenced normalized burn ratio (dNBR) to quantify severity in both fires and took a hypothesis-testing approach to answering two questions: First, was severity in the Biscuit Fire associated with severity in the Silver Fire in unmanaged areas? And second, did areas that were salvaged-logged and planted with conifers after the Silver Fire burn more or less severely in the Biscuit Fire than comparable unmanaged areas? I found that areas that burned severely in 1987 tended to re-burn at high severity in 2002, after controlling for the influence of several topographical and biophysical covariates. Areas unaffected by the initial fire tended to burn at the lowest severities in 2002. In addition, areas that were salvage-logged and planted after the initial fire burned more severely than comparable unmanaged areas, suggesting that post-fire logging and planting did not reduce future fire severity as had been suggested by some. In chapter three, I again focused on the twice-burned landscape, but this time I used a temporal sequence of digital aerial photography plots (6.25 ha) to measure changes in shrub-stratum, hardwood, and conifer cover. I estimated the strength and nature of relationships between crown damage and several fuel, topographical, weather, and management variables. Median crown damage, including damage to the shrub-stratum, on unmanaged plots was 63% after the Biscuit Fire and was most strongly related to damage in the Silver Fire. Plots that burned severely in the Silver Fire and had succeeded to a mix of shrubs and tree regeneration experienced high levels of Biscuit Fire damage. Plots dominated by large conifer cover after the Silver Fire had the lowest levels of Biscuit Fire canopy damage. Median crown damage was 39% for conifer cover and 85% for hardwood cover, and was most strongly related to daily average temperature and "burn period," an index of fire weather and fire suppression effort. Damage in the tree-stratum was largely independent of Silver Fire severity. Plots that had experienced stand replacing fire in 1987 and then were logged and planted with conifers had median crown damage of 100%. Plots that experienced a stand replacing fire but were unmanaged had median crown damage of 95%. The managed areas were at higher topographical positions and had greater total pre-fire cover, which may explain the small difference. These results suggest that in productive, fire-prone landscapes, the patch mosaic of young regenerating forest created by mixed-severity fire can structure the severity pattern of future wildfires occurring at short intervals and support the previous studies findings that post-fire logging and planting did not reduce fire severity. In Chapter four, I expanded my focus to include the entire region burned by the Biscuit Fire and again used digital aerial photos taken before and after the fire to interpret patterns of crown damage and relate them to several fuel, topographical, weather, and management variables. Ninety-eight percent of plots experienced some level of crown damage, but only 10% experienced complete crown damage. The median level of crown damage on unmanaged plots was 74%. Median conifer damage was 52%. The most important predictors of total crown damage were the percentage of pre-fire shrub-stratum vegetation cover and average daily temperature. The most important predictors of conifer damage were average daily temperature and burn period. Increasing levels of shrub-stratum cover were associated with increasing levels of conifer damage and hardwood damage. Large conifers had 32% median crown damage while small conifers had 62% median crown damage. Owing largely to widespread shrub-stratum cover, low-productivity ultramafic soils had 92% median crown damage compared to 59% on non-ultramafic sites. Patterns of damage were similar within the area that burned previously in the 1987 Silver Fire and edaphically comparable areas without a recently history of fire. Median crown damage in conifer plantations was 89% and plantation age was, by far, the most important predictor of the level of damage. Plantations under 20 years old experienced the highest rates of damage. I conclude that weather and vegetation conditions--not topography--were the primary determinants of Biscuit Fire crown damage. These findings suggest that in productive fire-prone ecosystems, fuel treatments that open tree canopies and stimulate shrub-stratum development may be counterproductive. Close

• 3172. [Article] The oligocene and miocene geology of the Tillamook embayment Tillamook County, northwest Oregon

  Eleven sedimentary and volcanic rock units are mapped and described in the thesis area, and chronicle the dynamic geologic history of the Tillamook embayment from the Oligocene through the middle Mlocene. ...

  Citation × Citation Citation Abstract Copy Title: The oligocene and miocene geology of the Tillamook embayment Tillamook County, northwest Oregon Author: Parker, Michael J. (Michael John), 1958- Eleven sedimentary and volcanic rock units are mapped and described in the thesis area, and chronicle the dynamic geologic history of the Tillamook embayment from the Oligocene through the middle Mlocene. The oldest unit is the Zemorrian to early Saucesian Smuggler Cove formation, a bathyal tuffaceous mudstone with some thin- to thick-bedded tuff layers deposited on the middle to upper continental slope during a period of explosive silicic volcanism in the Western Cascade arc. Uppermost Smuggler Cove strata are coarser grained, grading upward to arkosic turbidite sandstone and mudstone and thick bloturbated silty sandstone deposited on the outer shelf during marine regression. This regression heralded the progradation of the overlying shallow-marine Bewley Creek formation (informal) depositional system. The Bewley Creek formation (informal) is proposed in this study for a sequence of pumiceous, volcaniclastic-rich lower Miocene feldspathic litharenites and lithic arkoses deposited during the Pillarlan-stage near the mouth of an ancestral Columbia River. The unit grades from bioturbated silty sandstone to fine-grained hummocky cross-stratified and coarser grained channelized sandstones deposited within, or peripheral to a wave-dominated delta or ebb tidal-delta channel complex. Progradatlon of the Bewley Creek formation may have been caused, in part, by increased volcaniclastic sedimentation attending a pulse of explosive volcanism in the adjacent Western Cascade arc. Reduced volcanic activity, possibly coupled with basin subsidence or eustatic sea level rise, resulted in deposition of mudstones of the Sutton Creek member (informal; proposed) of the Nye Mudstone. The Saucesian Sutton Creek member consists of bathyal, laminated, carbonaceous, and moderately tuffaceous mudstone deposited in an upper continental slope basin. The upper part of the unit contains common lithic to arkosic turbidite sandstone interbeds within nested channel-fill deposits. These strata represent a channelized shelf-slope break environment adjacent to the shallow-marine Angora Peak member of the Astoria Formation depositlonal system. Subsequent marine regression resulted in progradation of the Pillarian- to Newportian-stage arkosic-micaceous sandstone-rich Angora Peak member into the Tillamook embayment. Grainsize analysis, sandstone petrography, scanning electron microscopy, and heavy mineral analyses suggest these lower to middle Miocene mollusk-bearing, fine- to medium-grained sandstones were predominantly deposited near the mouth of an ancestral Columbia River. They accumulated on a high-energy Inner shelf within or down drift of a wave-dominated delta or ebb-tidal delta complex, evidenced by paleocurrent analyses, hummocky cross-stratification and trough cross-stratified submarine channel-fill sequences. The Angora Peak member disconformably overlies Zemorrian mudstones of the Smuggler Cove formation at Cape Kiwanda suggesting local uplift and erosion in that area, followed by Newportian stage transgression in the Tillamook embayment. Exotic cobbles and boulders of two mica granite and sedimentary quartzite at Cape Kiwanda were probably derived from the Idaho Batholith and Precambrian sandstone terrains in Montana, transported via an ancestral Columbia River and longshore current to the shelf possibly bound within tree root bundles. The Netarts Bay member (informal) of the Astoria Formation Is proposed In this study for a late Sauceslan package of fine-grained to pebbly amalgamated and interbedded turbidite, grainflow, and fluldized flow friable thick-bedded lithic arkoses. These massive sandstones contain large penecontemporaneously emplaced channel wall-blocks and naller slltstone rip-ups. These lower to middle Miocene strata were deposited in a submarine canyon head and channel complex offshore of the shallow-marine Angora Peak member depositlonal system. Netarts Bay strata cut Into the underlying Angora Peak shelf strata, and cut and Interfinger with bathyal slope mudstones of the Cannon Beach member of the Astoria Formation. The overlying lower Cannon Beach member Is composed of laminated bathyal mudstones with rare turbidite sandstone interbeds deposited in a coarse clastic-starved slope environment. Upper Cannon Beach member strata In the Tillamook area are characterized by micaceous arkosic and lithic arkosic turbidite sandstones that underlie and occur within nested channel-fill sequences. Bloturbated carbonaceous cross-bedded sandstone In the upper Cannon Beach member records shallowing of the Tillamook embayment to a channelized upper slope to shelf environment. The Tillamook embayment was uplifted and dissected prior to the arrival of six to ten Intracanyon subaerial and submarine lava flows of the Columbia River Basalt Group. These middle Miocene flows, delineatedon the basis of geochemical composition and magnetic polarity, Include (in stratigraphic order) the Grouse Creek (R2 low MgO-low T102), Winterwater (N2 low MgO-low Ti02), and Sentinel Bluffs (high MgO) units of the Grande Ronde Basalt, and the Ginkgo unit of the Frenchman Springs member of the Wanapum Basalt. Orientation of Grande Ponde Basalt foreset-bedded pillow palagonite complexes and lava delta sequences indicate that these Columbia River Basalt units flowed westward into the Tillainook embayment, possibly through a saddle in the ancestral Oregon Coast Range. Marine transgression and deposition of hummocky cross-stratified arkosic marine strata of the Sandstone of Whale Cove followed emplacement of the last Grande Ronde flows. This was succeeded by a regression, as Indicated by the overlying subaerial plagioclase-phyric Ginkgo Unit flow of the Frenchman Springs Basalt. Locally, Winterwater and Sentinel Bluffs unit basalt occur as brecciated peperitic sills and dikes. These were emplaced through the process of "auto-invasion" when dense lava injected downward Into semi-lithifled Tertiary strata under the influence of both a pressure head augmented by flashing steam, and steam blasting. The thesis area is crossed by a complex network of high-angle northwest- and northeast-tending normal and reverse faults, and both low and high-angle east-trending reverse and thrust faults. These faults may have developed through a north-south compressional tectonic regime, a dextral shear couple, or a combination of these two tectonic regimes. Many faults cut Columbia River Basalt units and are thus middle Miocene or younger in age. Tertiary strata including the Columbia River Basalts are also folded within a broad westward-plunging syncline which suggests a middle Miocene or younger compressional event. Source rock analyses indicate that the mudstones of the Cannon Beach member, Sutton Creek member, and Smuggler Cove formation contain type III kerogen capable of generating natural gas only. Although these rocks have thermally innature vitrinite reflectance values, they contain sufficiently high total organic carbon content to be considered potential lean source rocks. Arkosic sandstones of the Angora Peak and Netarts Bay members have fair to good reservoir rock characteristics, and may represent reservoirs offshore for matured hydrocarbons generated from deeply buried source rocks. Title: The oligocene and miocene geology of the Tillamook embayment Tillamook County, northwest Oregon Author: Parker, Michael J. (Michael John), 1958- Eleven sedimentary and volcanic rock units are mapped and described in the thesis area, and chronicle the dynamic geologic history of the Tillamook embayment from the Oligocene through the middle Mlocene. The oldest unit is the Zemorrian to early Saucesian Smuggler Cove formation, a bathyal tuffaceous mudstone with some thin- to thick-bedded tuff layers deposited on the middle to upper continental slope during a period of explosive silicic volcanism in the Western Cascade arc. Uppermost Smuggler Cove strata are coarser grained, grading upward to arkosic turbidite sandstone and mudstone and thick bloturbated silty sandstone deposited on the outer shelf during marine regression. This regression heralded the progradation of the overlying shallow-marine Bewley Creek formation (informal) depositional system. The Bewley Creek formation (informal) is proposed in this study for a sequence of pumiceous, volcaniclastic-rich lower Miocene feldspathic litharenites and lithic arkoses deposited during the Pillarlan-stage near the mouth of an ancestral Columbia River. The unit grades from bioturbated silty sandstone to fine-grained hummocky cross-stratified and coarser grained channelized sandstones deposited within, or peripheral to a wave-dominated delta or ebb tidal-delta channel complex. Progradatlon of the Bewley Creek formation may have been caused, in part, by increased volcaniclastic sedimentation attending a pulse of explosive volcanism in the adjacent Western Cascade arc. Reduced volcanic activity, possibly coupled with basin subsidence or eustatic sea level rise, resulted in deposition of mudstones of the Sutton Creek member (informal; proposed) of the Nye Mudstone. The Saucesian Sutton Creek member consists of bathyal, laminated, carbonaceous, and moderately tuffaceous mudstone deposited in an upper continental slope basin. The upper part of the unit contains common lithic to arkosic turbidite sandstone interbeds within nested channel-fill deposits. These strata represent a channelized shelf-slope break environment adjacent to the shallow-marine Angora Peak member of the Astoria Formation depositlonal system. Subsequent marine regression resulted in progradation of the Pillarian- to Newportian-stage arkosic-micaceous sandstone-rich Angora Peak member into the Tillamook embayment. Grainsize analysis, sandstone petrography, scanning electron microscopy, and heavy mineral analyses suggest these lower to middle Miocene mollusk-bearing, fine- to medium-grained sandstones were predominantly deposited near the mouth of an ancestral Columbia River. They accumulated on a high-energy Inner shelf within or down drift of a wave-dominated delta or ebb-tidal delta complex, evidenced by paleocurrent analyses, hummocky cross-stratification and trough cross-stratified submarine channel-fill sequences. The Angora Peak member disconformably overlies Zemorrian mudstones of the Smuggler Cove formation at Cape Kiwanda suggesting local uplift and erosion in that area, followed by Newportian stage transgression in the Tillamook embayment. Exotic cobbles and boulders of two mica granite and sedimentary quartzite at Cape Kiwanda were probably derived from the Idaho Batholith and Precambrian sandstone terrains in Montana, transported via an ancestral Columbia River and longshore current to the shelf possibly bound within tree root bundles. The Netarts Bay member (informal) of the Astoria Formation Is proposed In this study for a late Sauceslan package of fine-grained to pebbly amalgamated and interbedded turbidite, grainflow, and fluldized flow friable thick-bedded lithic arkoses. These massive sandstones contain large penecontemporaneously emplaced channel wall-blocks and naller slltstone rip-ups. These lower to middle Miocene strata were deposited in a submarine canyon head and channel complex offshore of the shallow-marine Angora Peak member depositlonal system. Netarts Bay strata cut Into the underlying Angora Peak shelf strata, and cut and Interfinger with bathyal slope mudstones of the Cannon Beach member of the Astoria Formation. The overlying lower Cannon Beach member Is composed of laminated bathyal mudstones with rare turbidite sandstone interbeds deposited in a coarse clastic-starved slope environment. Upper Cannon Beach member strata In the Tillamook area are characterized by micaceous arkosic and lithic arkosic turbidite sandstones that underlie and occur within nested channel-fill sequences. Bloturbated carbonaceous cross-bedded sandstone In the upper Cannon Beach member records shallowing of the Tillamook embayment to a channelized upper slope to shelf environment. The Tillamook embayment was uplifted and dissected prior to the arrival of six to ten Intracanyon subaerial and submarine lava flows of the Columbia River Basalt Group. These middle Miocene flows, delineatedon the basis of geochemical composition and magnetic polarity, Include (in stratigraphic order) the Grouse Creek (R2 low MgO-low T102), Winterwater (N2 low MgO-low Ti02), and Sentinel Bluffs (high MgO) units of the Grande Ronde Basalt, and the Ginkgo unit of the Frenchman Springs member of the Wanapum Basalt. Orientation of Grande Ponde Basalt foreset-bedded pillow palagonite complexes and lava delta sequences indicate that these Columbia River Basalt units flowed westward into the Tillainook embayment, possibly through a saddle in the ancestral Oregon Coast Range. Marine transgression and deposition of hummocky cross-stratified arkosic marine strata of the Sandstone of Whale Cove followed emplacement of the last Grande Ronde flows. This was succeeded by a regression, as Indicated by the overlying subaerial plagioclase-phyric Ginkgo Unit flow of the Frenchman Springs Basalt. Locally, Winterwater and Sentinel Bluffs unit basalt occur as brecciated peperitic sills and dikes. These were emplaced through the process of "auto-invasion" when dense lava injected downward Into semi-lithifled Tertiary strata under the influence of both a pressure head augmented by flashing steam, and steam blasting. The thesis area is crossed by a complex network of high-angle northwest- and northeast-tending normal and reverse faults, and both low and high-angle east-trending reverse and thrust faults. These faults may have developed through a north-south compressional tectonic regime, a dextral shear couple, or a combination of these two tectonic regimes. Many faults cut Columbia River Basalt units and are thus middle Miocene or younger in age. Tertiary strata including the Columbia River Basalts are also folded within a broad westward-plunging syncline which suggests a middle Miocene or younger compressional event. Source rock analyses indicate that the mudstones of the Cannon Beach member, Sutton Creek member, and Smuggler Cove formation contain type III kerogen capable of generating natural gas only. Although these rocks have thermally innature vitrinite reflectance values, they contain sufficiently high total organic carbon content to be considered potential lean source rocks. Arkosic sandstones of the Angora Peak and Netarts Bay members have fair to good reservoir rock characteristics, and may represent reservoirs offshore for matured hydrocarbons generated from deeply buried source rocks. Close

• 3173. [Article] Structure of the southern Mormon Mountains, Clark County, Nevada and regional structural synthesis : fold-thrust and basin-range structure in southern Nevada, southwest Utah, and northwest Arizona

  Detailed geologic mapping in the Mormon Mountains and new geophysical data provide significant insight into contractional and extensional tectonics in southern Nevada, southwest Utah, and northwest Arizona. ...

  Citation × Citation Citation Abstract Copy Title: Structure of the southern Mormon Mountains, Clark County, Nevada and regional structural synthesis : fold-thrust and basin-range structure in southern Nevada, southwest Utah, and northwest Arizona Author: Carpenter, James Anthony Detailed geologic mapping in the Mormon Mountains and new geophysical data provide significant insight into contractional and extensional tectonics in southern Nevada, southwest Utah, and northwest Arizona. The rocks in the region were complexly deformed during two distinct tectonic episodes. Numerous interrelated events occurred within each episode. The first tectonic episode, related to the Sevier orogeny, was characterized by east-west crustal shortening which culminated in thin-skinned decollement style folding and thrusting during the Cretaceous. The Virgin-Beaver Dam Mountains anticline, a Laramide-type basement-involved uplift, represents the only thick-skinned contractional structure in the region. The second tectonic episode, related to basin-range rifting, was characterized by east-west crustal extension which was accommodated by high-angle normal faults, with dips averaging 60 degrees, in the brittle upper crust. In this area, basin-range rifting initiated in the Oligocene and continued to Recent time. Relations in the North Muddy Mountains in southern Nevada suggest that the Muddy Mountain thrust sheet advanced and overrode the Weiser syncline during the Cenomanian and may have continued to advance in Turonian time. In the southern Mormon Mountains, the Cambrian Bonanza King Formation lies in the hanging wall flat position in thrust contact with the overturned Petrified Forest Member of the Triassic Chinle Formation at the footwall ramp. The thrust sheet advanced eastward more than 30 km from the place of origin. Thrust imbrication, and probably the formation of hanging wall horses, likely occurred as the Muddy Mountain thrust sheet encountered and ascended up the footwall ramp zone (composed largely of competent carbonate rocks) where slices of the thrust sheet (hanging wall horses) splayed of f and accreted to the footwall ramp zone. A detailed retrodeformable (balanced) regional structure section suggests that fold-thrust shortening at the latitude of the Mormon Mountains is a minimum of about 26%. Extension-related structures overprint older fold-thrust structures in the Mormon Mountains. The west-plunging east-trending Candy Peak syncline is one of a family of fold structures related to basin-range rifting. The syncline formed in pre-Miocene time in association with the northeast-striking Reber Mountain normal fault directly north and the northeast-striking Dry Canyon right-lateral strike-slip fault directly south. The Tortoise Flat synform, which lies southeast of the Dry Canyon fault, developed in Miocene and possibly Pliocene time by right-lateral flexure of early Miocene Horse Spring beds as a result of drag associated with the Dry Canyon fault. The Dry Canyon fault and the Tortoise Flat synform are interpreted to be part of the right-lateral Moapa Peak-Reber Mountain shear zone system in the southern Mormon Mountains. Therefore, the time of formation of the Moapa Peak-Reber Mountain shear zone system is pre-Miocene to possibly Pliocene. The shear zone system formed in response to different amounts of west-directed extension-related movement of the hanging wall block of the high-angle Virgin Beaver Dam Mountains fault, which initiated in the Oligocene. From this, the timing of the Moapa Peak-Reber Mountain shear zone, system is interpreted as Oligocene to Miocene, and possibly Pliocene. The interpretation of 261 km of seismic reflection sections suggests that large-displacement high-angle normal faults, typically with 60 degrees of dip, control horst and graben structure and accommodate extension by simple shear in the upper brittle crust. Such faults likely extend to depths of 15 to 18 km. Below this depth extension is thought to be accommodated by penetrative ductile deformation. A detailed retrodeformable (balanced) regional structure section suggests that basin-range extension at the latitude of the Mormon Mountains is about 17%. The Virgin-Beaver Dam Mountains high-angle normal fault is a large-displacement master fault in the area, having more than 8,000 in of normal vertical separation at the latitude of the Virgin Valley basin depocenter. Miocene doming and uplift of the Mormon Mountains occurred in response to displacement on the Virgin-Beaver Dam Mountains fault. The Virgin Valley basin formed as the hanging wall block downdropped, and the Mormon Mountains dome formed by relative uplift at the opposite end of the hanging wall block. Half-grabens, and tilted, folded, and faulted range blocks characterize basin-range crustal structure. Depositional growth relations are interpreted in basins from fanning-upward reflector geometry, and the wedge-shape of Oligocene to Recent syntectonic basin-fill sediments. Non-overlapping opposing east- and west-tilted half-grabens compose the Meadow Valley-California Wash basin. Seismic sections, gravity data, well data, and geologic mapping demonstrate that the Mormon Peak, Tule Springs Hills, and Beaver Dam/Castle Cliff "detachments," which were thought to be rooted low-angle normal faults, do not exist. The Mormon Peak and Beaver Dam/Castle Cliff low-angle normal faults are denudational fault planes below gravity slid masses. The widely distributed translocated Paleozoic blocks, which were thought to be remnant pieces of large hanging wall sheets ("extensional allochthons"), are disjunct rootless gravity slide blocks of minor tectonic significance. A large number of these rootless slide blocks lie on Pliocene and Quaternary basin-fill deposits. The Muddy Mountain-Tule Springs thrust, of Sevier age, was not reactivated as a crustal penetrating Tule Springs Hills low-angle normal fault, but is affected by small-scale gravity slide features. Rootless gravity slide blocks, secondary features to high-angle normal faults, commonly occur from instability as a result of the loss of lateral support induced by block faulting and the associated erosion of range blocks. Title: Structure of the southern Mormon Mountains, Clark County, Nevada and regional structural synthesis : fold-thrust and basin-range structure in southern Nevada, southwest Utah, and northwest Arizona Author: Carpenter, James Anthony Detailed geologic mapping in the Mormon Mountains and new geophysical data provide significant insight into contractional and extensional tectonics in southern Nevada, southwest Utah, and northwest Arizona. The rocks in the region were complexly deformed during two distinct tectonic episodes. Numerous interrelated events occurred within each episode. The first tectonic episode, related to the Sevier orogeny, was characterized by east-west crustal shortening which culminated in thin-skinned decollement style folding and thrusting during the Cretaceous. The Virgin-Beaver Dam Mountains anticline, a Laramide-type basement-involved uplift, represents the only thick-skinned contractional structure in the region. The second tectonic episode, related to basin-range rifting, was characterized by east-west crustal extension which was accommodated by high-angle normal faults, with dips averaging 60 degrees, in the brittle upper crust. In this area, basin-range rifting initiated in the Oligocene and continued to Recent time. Relations in the North Muddy Mountains in southern Nevada suggest that the Muddy Mountain thrust sheet advanced and overrode the Weiser syncline during the Cenomanian and may have continued to advance in Turonian time. In the southern Mormon Mountains, the Cambrian Bonanza King Formation lies in the hanging wall flat position in thrust contact with the overturned Petrified Forest Member of the Triassic Chinle Formation at the footwall ramp. The thrust sheet advanced eastward more than 30 km from the place of origin. Thrust imbrication, and probably the formation of hanging wall horses, likely occurred as the Muddy Mountain thrust sheet encountered and ascended up the footwall ramp zone (composed largely of competent carbonate rocks) where slices of the thrust sheet (hanging wall horses) splayed of f and accreted to the footwall ramp zone. A detailed retrodeformable (balanced) regional structure section suggests that fold-thrust shortening at the latitude of the Mormon Mountains is a minimum of about 26%. Extension-related structures overprint older fold-thrust structures in the Mormon Mountains. The west-plunging east-trending Candy Peak syncline is one of a family of fold structures related to basin-range rifting. The syncline formed in pre-Miocene time in association with the northeast-striking Reber Mountain normal fault directly north and the northeast-striking Dry Canyon right-lateral strike-slip fault directly south. The Tortoise Flat synform, which lies southeast of the Dry Canyon fault, developed in Miocene and possibly Pliocene time by right-lateral flexure of early Miocene Horse Spring beds as a result of drag associated with the Dry Canyon fault. The Dry Canyon fault and the Tortoise Flat synform are interpreted to be part of the right-lateral Moapa Peak-Reber Mountain shear zone system in the southern Mormon Mountains. Therefore, the time of formation of the Moapa Peak-Reber Mountain shear zone system is pre-Miocene to possibly Pliocene. The shear zone system formed in response to different amounts of west-directed extension-related movement of the hanging wall block of the high-angle Virgin Beaver Dam Mountains fault, which initiated in the Oligocene. From this, the timing of the Moapa Peak-Reber Mountain shear zone, system is interpreted as Oligocene to Miocene, and possibly Pliocene. The interpretation of 261 km of seismic reflection sections suggests that large-displacement high-angle normal faults, typically with 60 degrees of dip, control horst and graben structure and accommodate extension by simple shear in the upper brittle crust. Such faults likely extend to depths of 15 to 18 km. Below this depth extension is thought to be accommodated by penetrative ductile deformation. A detailed retrodeformable (balanced) regional structure section suggests that basin-range extension at the latitude of the Mormon Mountains is about 17%. The Virgin-Beaver Dam Mountains high-angle normal fault is a large-displacement master fault in the area, having more than 8,000 in of normal vertical separation at the latitude of the Virgin Valley basin depocenter. Miocene doming and uplift of the Mormon Mountains occurred in response to displacement on the Virgin-Beaver Dam Mountains fault. The Virgin Valley basin formed as the hanging wall block downdropped, and the Mormon Mountains dome formed by relative uplift at the opposite end of the hanging wall block. Half-grabens, and tilted, folded, and faulted range blocks characterize basin-range crustal structure. Depositional growth relations are interpreted in basins from fanning-upward reflector geometry, and the wedge-shape of Oligocene to Recent syntectonic basin-fill sediments. Non-overlapping opposing east- and west-tilted half-grabens compose the Meadow Valley-California Wash basin. Seismic sections, gravity data, well data, and geologic mapping demonstrate that the Mormon Peak, Tule Springs Hills, and Beaver Dam/Castle Cliff "detachments," which were thought to be rooted low-angle normal faults, do not exist. The Mormon Peak and Beaver Dam/Castle Cliff low-angle normal faults are denudational fault planes below gravity slid masses. The widely distributed translocated Paleozoic blocks, which were thought to be remnant pieces of large hanging wall sheets ("extensional allochthons"), are disjunct rootless gravity slide blocks of minor tectonic significance. A large number of these rootless slide blocks lie on Pliocene and Quaternary basin-fill deposits. The Muddy Mountain-Tule Springs thrust, of Sevier age, was not reactivated as a crustal penetrating Tule Springs Hills low-angle normal fault, but is affected by small-scale gravity slide features. Rootless gravity slide blocks, secondary features to high-angle normal faults, commonly occur from instability as a result of the loss of lateral support induced by block faulting and the associated erosion of range blocks. Close

• 3174. [Article] Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs

  Flaxseed is a rich source of alpha-linolenic acid (ALA). Feeding laying hens flax seed can increase n-3 fatty acids content (FA) in eggs, thus increasing human intake of n-3 FA. However, non-starch polysaccharides ...

  Citation × Citation Citation Abstract Copy Title: Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs Author: Westbrook, Lindsay A. Flaxseed is a rich source of alpha-linolenic acid (ALA). Feeding laying hens flax seed can increase n-3 fatty acids content (FA) in eggs, thus increasing human intake of n-3 FA. However, non-starch polysaccharides (NSP), which decreases digestibility of dietary lipids and proteins. Addition of carbohydrase enzymes to flax-based layer diets can alter the anti-nutritive effects of NSP. Three experiments were conducted to investigate the effect of dietary supplementation of flaxseed and carbohydrase enzyme on hen production performance, egg quality, egg and hen liver tissue FA composition, and foregut morphology in layer hens. A total of seventy-two brown layer hens were assigned to one of four dietary treatments: corn-soybean based diet (Control), Control plus 10% flax (Diet 1), Diet 1 +0.05% carbohydrase enzyme (Diet 2), and Diet 1 + 0.1% carbohydrase enzyme (Diet 3). All diets were isocaloric and isonitrogenous. Hens received the dietary treatments for a total of 4 months. Hens fed Diet 1 exhibited a trend for highest egg hen day production among the four dietary treatments (P=0.09). Hen age led to a reduction in egg production in all four dietary treatments during the four month feeding trial (P<0.0001). Both egg weight and yolk weight were significantly higher in hens fed Diet 2 (P=0.008). During the six week storage period, egg weight and yolk weight were significantly higher in hens fed Diet 2 and Diet 3 (P=0.005, P=0.044) as compared to the Control. Hens receiving Diet 3 showed a trend for a high yolk pH (P=0.083), while Diet 3 displayed a significantly higher albumen pH (P<0.0001). Egg fatty acids were influenced by diet composition. Linoleic acid (LA) and arachidonic acid (AA) were highest in Control eggs (P<0.0001). ALA was highest in eggs from hens fed Diet 3 (P=0.009). DHA was significantly increased in eggs from hens fed Diet 1, Diet 2, and Diet 3 (P<0.0001) relative to the Control. Total n-3 FA was highest in hens consuming Diet 3 (P<0.0001) (>1.7 fold-increase compared to Control). Total long chain (>20 carbons) n-3 FA concentrations were highest among eggs from hens fed Diets 1, 2, and 3 (P<.0001). Egg total lipids showed no significant difference among the four dietary treatments. A significant increase in ALA content was observed in the liver of hens fed Diets 1 and 3 (P<.0001) relative to the Control diet. There was a significant increase in LA and AA in liver of hens fed the Control as compared to Diets 1, 2, and 3 (P<0.0001). Furthermore, total n-6 FA were also significantly higher in the Control and Diet 1, while there was a significant increase in total n-3 FA seen in fed receiving Diet 1, 2, and 3. Liver DHA (22:6 n-3) content in hens fed Diets 1, 2, and 3 increased by an average of 2.27% relative to the Control. As for long chain n-3, there was a significant increase in the liver of hens receiving Diets 1, 2, and 3 as compared to the Control. Hen liver total lipids were significantly higher in hens fed Diets 1, 2, and 3 (P=0.0009). There was a significant increase in thiobarbituric acid-reactive substances (TBARS) eggs from in hens fed Diet 3 (P<.0001). In the duodenum, flaxseed and enzyme supplementation led to a significant increase in villi height (P<0.0001). Villi width was also significantly greater in hens fed Diets 1, 2, and 3 (P<0.0001). However, the addition of flaxseed and enzyme led to a trend with Diet 3 having the lowest crypt depth (P= 0.066) in the duodenum. Hens fed Diet 1 and Diet 3 had significantly increased villi height:crypt depth ratio (P<0.0001). In the jejunum, hens fed flaxseed and enzyme supplementation also had significantly increased villi height (P<0.0001). In addition, hens fed Diets 2 and Diet 3 displayed a significant increase in villi width (P<0.0001). Both crypt depth and villi height:crypt depth ratio showed no significant difference among the four dietary treatments. In conclusion, the combination of whole flaxseed plus carbohydrase enzymes leads to degradation of NSP in flaxseed and increases the availability of ALA and other nutrients. Egg and liver from hens fed Diet 2 and 3 experienced over a 50% increase in total n-3 FA. There is evidence that feeding hens an enzyme supplement along with high levels of ALA produces significant changes in gut morphology, increasing jejunum villi surface area. These studies confirm that the use of carbohydrase enzymes can result in degradation of NSP in whole flaxseed and increase availability of ALA and other nutrients to layer hens without hindering production performance. Title: Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs Author: Westbrook, Lindsay A. Flaxseed is a rich source of alpha-linolenic acid (ALA). Feeding laying hens flax seed can increase n-3 fatty acids content (FA) in eggs, thus increasing human intake of n-3 FA. However, non-starch polysaccharides (NSP), which decreases digestibility of dietary lipids and proteins. Addition of carbohydrase enzymes to flax-based layer diets can alter the anti-nutritive effects of NSP. Three experiments were conducted to investigate the effect of dietary supplementation of flaxseed and carbohydrase enzyme on hen production performance, egg quality, egg and hen liver tissue FA composition, and foregut morphology in layer hens. A total of seventy-two brown layer hens were assigned to one of four dietary treatments: corn-soybean based diet (Control), Control plus 10% flax (Diet 1), Diet 1 +0.05% carbohydrase enzyme (Diet 2), and Diet 1 + 0.1% carbohydrase enzyme (Diet 3). All diets were isocaloric and isonitrogenous. Hens received the dietary treatments for a total of 4 months. Hens fed Diet 1 exhibited a trend for highest egg hen day production among the four dietary treatments (P=0.09). Hen age led to a reduction in egg production in all four dietary treatments during the four month feeding trial (P<0.0001). Both egg weight and yolk weight were significantly higher in hens fed Diet 2 (P=0.008). During the six week storage period, egg weight and yolk weight were significantly higher in hens fed Diet 2 and Diet 3 (P=0.005, P=0.044) as compared to the Control. Hens receiving Diet 3 showed a trend for a high yolk pH (P=0.083), while Diet 3 displayed a significantly higher albumen pH (P<0.0001). Egg fatty acids were influenced by diet composition. Linoleic acid (LA) and arachidonic acid (AA) were highest in Control eggs (P<0.0001). ALA was highest in eggs from hens fed Diet 3 (P=0.009). DHA was significantly increased in eggs from hens fed Diet 1, Diet 2, and Diet 3 (P<0.0001) relative to the Control. Total n-3 FA was highest in hens consuming Diet 3 (P<0.0001) (>1.7 fold-increase compared to Control). Total long chain (>20 carbons) n-3 FA concentrations were highest among eggs from hens fed Diets 1, 2, and 3 (P<.0001). Egg total lipids showed no significant difference among the four dietary treatments. A significant increase in ALA content was observed in the liver of hens fed Diets 1 and 3 (P<.0001) relative to the Control diet. There was a significant increase in LA and AA in liver of hens fed the Control as compared to Diets 1, 2, and 3 (P<0.0001). Furthermore, total n-6 FA were also significantly higher in the Control and Diet 1, while there was a significant increase in total n-3 FA seen in fed receiving Diet 1, 2, and 3. Liver DHA (22:6 n-3) content in hens fed Diets 1, 2, and 3 increased by an average of 2.27% relative to the Control. As for long chain n-3, there was a significant increase in the liver of hens receiving Diets 1, 2, and 3 as compared to the Control. Hen liver total lipids were significantly higher in hens fed Diets 1, 2, and 3 (P=0.0009). There was a significant increase in thiobarbituric acid-reactive substances (TBARS) eggs from in hens fed Diet 3 (P<.0001). In the duodenum, flaxseed and enzyme supplementation led to a significant increase in villi height (P<0.0001). Villi width was also significantly greater in hens fed Diets 1, 2, and 3 (P<0.0001). However, the addition of flaxseed and enzyme led to a trend with Diet 3 having the lowest crypt depth (P= 0.066) in the duodenum. Hens fed Diet 1 and Diet 3 had significantly increased villi height:crypt depth ratio (P<0.0001). In the jejunum, hens fed flaxseed and enzyme supplementation also had significantly increased villi height (P<0.0001). In addition, hens fed Diets 2 and Diet 3 displayed a significant increase in villi width (P<0.0001). Both crypt depth and villi height:crypt depth ratio showed no significant difference among the four dietary treatments. In conclusion, the combination of whole flaxseed plus carbohydrase enzymes leads to degradation of NSP in flaxseed and increases the availability of ALA and other nutrients. Egg and liver from hens fed Diet 2 and 3 experienced over a 50% increase in total n-3 FA. There is evidence that feeding hens an enzyme supplement along with high levels of ALA produces significant changes in gut morphology, increasing jejunum villi surface area. These studies confirm that the use of carbohydrase enzymes can result in degradation of NSP in whole flaxseed and increase availability of ALA and other nutrients to layer hens without hindering production performance. Close

• 3175. [Article] Selection on larval and adult body size in a marine fish: potential evolutionary responses and effects on population dynamics

  Many species have complex life cycles in which a dispersive larval stage is followed by a relatively sedentary adult stage. For such species, reproductive output is often high and large variation in survivorship ...

  Citation × Citation Citation Abstract Copy Title: Selection on larval and adult body size in a marine fish: potential evolutionary responses and effects on population dynamics Author: Johnson, Darren W. Many species have complex life cycles in which a dispersive larval stage is followed by a relatively sedentary adult stage. For such species, reproductive output is often high and large variation in survivorship throughout early life-history phases (eggs and larvae) can lead to dramatic fluctuations in recruitment which may in turn drive variation in the abundance of juveniles and adults. Early in the life cycle may therefore be a critical period for both natural selection and population dynamics. On one hand, variability in survival during early stages may provide ample opportunity for selection on early life-history traits. On the other hand, phenotypic variation in early life-history traits and selective mortality may be an important source of variability in population dynamics. Variation in survival of marine fish larvae may be a major driver of variability in benthic population size. However, little is known about how variation in larval phenotype may affect larval survival, and less in known about the evolutionary potential of marine fish larvae. I quantified both environmental and genetic sources of variation in larval traits for a field population of a common Atlantic and Caribbean coral-reef fish, the bicolor damselfish (Pomacentridae: Stegastes partitus). I combined field demographic studies and manipulative experiments in the Bahamas to estimate heritability and quantitative genetic parameters for both larval size and swimming performance – two traits that are associated with early survival. I also compiled published estimates of viability selection on larval size from eight species of fish to estimate the average magnitude of selection on this trait. The initial results of these analyses were somewhat paradoxical. Despite ample heritability (h2 = 0.29 for larval size), and strong selection on larval size (mean selection differential = 0.484), the observed mean larval size is quite far from the estimated phenotypic optimum (0.481 standard deviations greater than current mean size), suggesting that marine fish larvae are on average, maladapted with respect to survival during the larval and juvenile phases. Further analyses focused on potential evolutionary constraints on larval size. First, I estimated trade-offs in individual reproductive output between larval quality and quantity. Mothers that produced larger larvae with greater swimming abilities tended to produce fewer larvae, and these effects explained a large component of the mismatch between mean larval size and the phenotypic optimum for survival. Fluctuation in direct selection on larvae may also partially explain why mean larval size is less than optimal. Evolution of larval size may also be strongly influenced by genetic correlations with body size expressed at later ages. I demonstrated substantial additive genetic covariance between adult asymptotic size and both larval size-at-hatching and swimming performance (0.212 and 0.241 on variancestandardized traits, respectively). Adult asymptotic size was also linked to larval traits via size-dependent maternal effects, in which larger mothers provisioned offspring with more yolk resources. Selection on adult body size may therefore cause a substantial correlated genetic response in larval size that may strongly affect the overall evolutionary trajectory of larval traits. I also examined natural selection on body size and growth form in S. partitus. Using data on size, growth and longevity of individual fish studied at 4 sites over a 7-year period, I analyzed both ontogenetic and spatial variation in the magnitude and direction of viability selection on body size. Selection on asymptotic (adult) size was strong and positive at some sites, but weak and negative at other sites. Moreover, fish that were small as juveniles generally experienced greater survival, even if large adult size conferred survival benefits later in life. Both spatial and ontogenetic reversals in selection on body size would be expected to produce similar reversals in the direction of correlated responses of larvae, thereby altering the evolutionary response of larvae and potentially preventing larval size from evolving toward its optimum value. Although this research identified several potential constraints on the evolution of larval traits, there is still considerable scope for an evolutionary response to selection, especially if selection is consistent and strong. Many marine fishes are subject to size-selective fishing where larger, fast-growing individuals are selectively removed from the population. Such effects are usually strong because fishing mortality rates can greatly exceed natural mortality rates and fishing selectivity and intensity are often constant. Although correlated responses to selection have been hypothesized as potentially important consequences of fishery selection, estimates of quantitative genetic parameters required to predict correlated responses to such selection have been lacking. To my knowledge, my research provides the first estimates of quantitative genetic parameters for larval traits and their links to adult size in a wild population of fish. I used these data to predict how larval size would respond to selection on adults and how evolutionary shifts in larval size would in turn affect population replenishment. My results predict that observed rates of fishery selection on adult marine fishes may decrease average larval size by approximately 0.11 standard deviations after a single generation of selection. Such a reduction in larval size is predicted to reduce survivorship through the larval and early juvenile phases by about 16%. Because the dynamics of many fish populations are highly sensitive to changes in survival of early life stages, the evolution of a higher incidence of low-quality larvae in response to fishery selection may have substantial consequences for the viability of fished populations. Overall, this research indicates that a complex interplay among trait variation, phenotypic selection, and demographic rates may have strong effects on both evolutionary responses and population dynamics. Our understanding of such interactions will be substantially advanced by applying evolutionary quantitative genetics to traditional studies of demography and population dynamics. A combination of these two approaches can yield significant insight into basic evolutionary questions (e.g., why larvae are smaller than expected), as well as applied conservation problems (e.g., predicting correlated responses to fishery selection). Title: Selection on larval and adult body size in a marine fish: potential evolutionary responses and effects on population dynamics Author: Johnson, Darren W. Many species have complex life cycles in which a dispersive larval stage is followed by a relatively sedentary adult stage. For such species, reproductive output is often high and large variation in survivorship throughout early life-history phases (eggs and larvae) can lead to dramatic fluctuations in recruitment which may in turn drive variation in the abundance of juveniles and adults. Early in the life cycle may therefore be a critical period for both natural selection and population dynamics. On one hand, variability in survival during early stages may provide ample opportunity for selection on early life-history traits. On the other hand, phenotypic variation in early life-history traits and selective mortality may be an important source of variability in population dynamics. Variation in survival of marine fish larvae may be a major driver of variability in benthic population size. However, little is known about how variation in larval phenotype may affect larval survival, and less in known about the evolutionary potential of marine fish larvae. I quantified both environmental and genetic sources of variation in larval traits for a field population of a common Atlantic and Caribbean coral-reef fish, the bicolor damselfish (Pomacentridae: Stegastes partitus). I combined field demographic studies and manipulative experiments in the Bahamas to estimate heritability and quantitative genetic parameters for both larval size and swimming performance – two traits that are associated with early survival. I also compiled published estimates of viability selection on larval size from eight species of fish to estimate the average magnitude of selection on this trait. The initial results of these analyses were somewhat paradoxical. Despite ample heritability (h2 = 0.29 for larval size), and strong selection on larval size (mean selection differential = 0.484), the observed mean larval size is quite far from the estimated phenotypic optimum (0.481 standard deviations greater than current mean size), suggesting that marine fish larvae are on average, maladapted with respect to survival during the larval and juvenile phases. Further analyses focused on potential evolutionary constraints on larval size. First, I estimated trade-offs in individual reproductive output between larval quality and quantity. Mothers that produced larger larvae with greater swimming abilities tended to produce fewer larvae, and these effects explained a large component of the mismatch between mean larval size and the phenotypic optimum for survival. Fluctuation in direct selection on larvae may also partially explain why mean larval size is less than optimal. Evolution of larval size may also be strongly influenced by genetic correlations with body size expressed at later ages. I demonstrated substantial additive genetic covariance between adult asymptotic size and both larval size-at-hatching and swimming performance (0.212 and 0.241 on variancestandardized traits, respectively). Adult asymptotic size was also linked to larval traits via size-dependent maternal effects, in which larger mothers provisioned offspring with more yolk resources. Selection on adult body size may therefore cause a substantial correlated genetic response in larval size that may strongly affect the overall evolutionary trajectory of larval traits. I also examined natural selection on body size and growth form in S. partitus. Using data on size, growth and longevity of individual fish studied at 4 sites over a 7-year period, I analyzed both ontogenetic and spatial variation in the magnitude and direction of viability selection on body size. Selection on asymptotic (adult) size was strong and positive at some sites, but weak and negative at other sites. Moreover, fish that were small as juveniles generally experienced greater survival, even if large adult size conferred survival benefits later in life. Both spatial and ontogenetic reversals in selection on body size would be expected to produce similar reversals in the direction of correlated responses of larvae, thereby altering the evolutionary response of larvae and potentially preventing larval size from evolving toward its optimum value. Although this research identified several potential constraints on the evolution of larval traits, there is still considerable scope for an evolutionary response to selection, especially if selection is consistent and strong. Many marine fishes are subject to size-selective fishing where larger, fast-growing individuals are selectively removed from the population. Such effects are usually strong because fishing mortality rates can greatly exceed natural mortality rates and fishing selectivity and intensity are often constant. Although correlated responses to selection have been hypothesized as potentially important consequences of fishery selection, estimates of quantitative genetic parameters required to predict correlated responses to such selection have been lacking. To my knowledge, my research provides the first estimates of quantitative genetic parameters for larval traits and their links to adult size in a wild population of fish. I used these data to predict how larval size would respond to selection on adults and how evolutionary shifts in larval size would in turn affect population replenishment. My results predict that observed rates of fishery selection on adult marine fishes may decrease average larval size by approximately 0.11 standard deviations after a single generation of selection. Such a reduction in larval size is predicted to reduce survivorship through the larval and early juvenile phases by about 16%. Because the dynamics of many fish populations are highly sensitive to changes in survival of early life stages, the evolution of a higher incidence of low-quality larvae in response to fishery selection may have substantial consequences for the viability of fished populations. Overall, this research indicates that a complex interplay among trait variation, phenotypic selection, and demographic rates may have strong effects on both evolutionary responses and population dynamics. Our understanding of such interactions will be substantially advanced by applying evolutionary quantitative genetics to traditional studies of demography and population dynamics. A combination of these two approaches can yield significant insight into basic evolutionary questions (e.g., why larvae are smaller than expected), as well as applied conservation problems (e.g., predicting correlated responses to fishery selection). Close

• 3176. [Article] Geology of the Green Mountain-Young's River area, Clatsop County, northwest Oregon

  The upper Eocene to lower Oligocene Oswald West mudstone is the oldest formation (informal) in the Green Mountain-Young's River area. This 1,663 meter thick hemipelagic sequence was deposited in a low-energy ...

  Citation × Citation Citation Abstract Copy Title: Geology of the Green Mountain-Young's River area, Clatsop County, northwest Oregon Author: Peterson, Carolyn Pugh The upper Eocene to lower Oligocene Oswald West mudstone is the oldest formation (informal) in the Green Mountain-Young's River area. This 1,663 meter thick hemipelagic sequence was deposited in a low-energy lower to upper slope environment in the Coast Range forearc basin. The formation ranges from the late Narizian to the early Zemorrian(?) in age and consists of thick-bedded bioturbated foraminiferal claystone and tuffaceous siltstone. Rare glauconitic sandstone beds also occur. In the eastern part of the study area, the upper part of the Oswald West mudstone is interbedded with the upper Refugian Klaskanine siltstone tongue. This informal unit consists of thick bioturbated sandy siltstone and silty sandstone that is a lateral deep-marine correlative of the deltaic to shallow-marine Pittsburg Bluff Formation in the northeastern Coast Range. Discontinuous underthrusting of the Juan de Fuca oceanic plate at the base of the continental slope of the North American plate caused extensive uplift and subsidence along the Oregon continental margin throughout the Cenozoic (Snavely et al., 1980). Initiation of Oregon Coast Range uplift and accompanying erosion in the early Miocene, coupled with a global low stand of sea level (Vail and Mitchum, 1979), stripped most of the Oligocene (Zemorrian) Oswald West strata and in places much of the uppermost Eocene (upper Refugian) Oswald West strata in the field area, creating an unconformity. Deformation accompanying uplift included a system of east-west-trending, oblique-slip faults. The Pillarian-to-Newportian Astoria Formation unconformably overlies the Oswald West mudstone and reflects deposition offshore from an open, storm-dominated coast during an early-to-middle Miocene transgression. Deposition of the Big Creek sandstone and Silver Point mudstone members of the Astoria Formation was controlled in part by submarine paleotopography that developed as a result of early Miocene deformation of the Oswald West strata. The up to 200 meter thick Big Creek member varies from storm-deposited laminated sandstone to bioturbated mollusk-bearing silty sandstone that accumulated during fair weather conditions on the inner to middle shelf. Overlying and perhaps in part laterally equivalent to the Big Creek member is the up to 200 meter thick, deeper marine Silver Point member which consists of two lithologies: 1) interbedded, micaceous, turbidite sandstones and laminated mudstone; and 2) laminated bathyal mudstone that intertongues with and caps the turbidite sequences. The turbidite lithology is composed of two facies: 1) an underlying sand-rich facies, transitional between the shallow-marine Big Creek member and bathyal Silver Point strata, that was deposited on the outer shelf by storm-induced turbidity currents; and 2) an overlying sand-poor facies that was deposited at bathyal depths. The turbidite facies channelized, and at some places removed the underlying Big Creek member and were deposited directly over Oswald West mudstone. The Astoria depositional sequence ranges, from inner to outer neritic to bathyal facies and reflects continued deepening and anoxic depositional conditions of the Astoria basin through the middle Miocene. Big Creek and Silver Point sandstone petrology reflects volcanic sources from an ancestral western Cascades volcanic arc and metamorphic and granitic basement rocks farther east via an ancestral Columbia River drainage system. Diagenetic effects include: (a) formation of local calcite concretionary cements; and (b) formation of pore-filling smectite from alteration of volcanic rock fragments. At least six middle Miocene Columbia River Basalt intrusive episodes affected the Green Mountain-Young's River area soon after deposition of the Astoria Formation. These basalt sills and dikes include normally polarized and reversely polarized low Mg0 high TiO₂, low Mg0 low TiO₂, and high Mg0 Grande Ronde basalt chemical subtypes and two porphyritic Frenchman Springs Member basalts (Ginkgo and Kelly Hollow(?) petrologic types). These basalt intrusions are virtually indistinguishable, based on chemistry, from subaerial flows of the plateau-derived Columbia River Basalt Group subtypes at nearby Nicolai Mountain and Porter Ridge. This correlation supports the Beeson et al. (1979) hypothesis that the intrusions are not of local origin but formed by the invasion of the flows into the Miocene shoreline sediments to form "invasive" sills and dikes. Many dikes were emplaced along northeast- and northwest-trending faults, and some (i.e., Ginkgo) cut older sills (Grande Ronde). A laterally extensive Frenchman Springs sill occurs under an older widespread Grande Ronde sill. From this older over younger intrusive relationship, a mechanism of "invasion" of sediment from overlying lava flows is difficult to envision. A pulse of rapid subduction starting in the middle Miocene (Snavely et al., 1980) was accompanied by renewed uplift, intensive block faulting, and continued development of the earlier formed Coast Range uplift. Left-oblique northeast-trending faults and conjugate northwest-trending right-oblique faults offset Grande Ronde and Frenchman Springs dikes and sills. This conjugate fault pattern may reflect oblique east-west convergence between the North American and Juan de Fuca plates. The Silver Point mudstones and Oswald West mudstones have high total organic carbon contents, up to 5.5%, but are thermally immature and may act only as a source for biogenic gas(?) in the subsurface. Suitable reservoir rocks, such as the gas-producing upper Eocene Cowlitz Formation C & W sandstone, may pinch out before reaching the Green Mountain-Young's River area and are yet to be penetrated by exploration drilling. Post-middle Miocene fault traps abound in the area, although these faults might also breach subsurface natural gas reservoirs in the Green Mountain-Young's River area. Title: Geology of the Green Mountain-Young's River area, Clatsop County, northwest Oregon Author: Peterson, Carolyn Pugh The upper Eocene to lower Oligocene Oswald West mudstone is the oldest formation (informal) in the Green Mountain-Young's River area. This 1,663 meter thick hemipelagic sequence was deposited in a low-energy lower to upper slope environment in the Coast Range forearc basin. The formation ranges from the late Narizian to the early Zemorrian(?) in age and consists of thick-bedded bioturbated foraminiferal claystone and tuffaceous siltstone. Rare glauconitic sandstone beds also occur. In the eastern part of the study area, the upper part of the Oswald West mudstone is interbedded with the upper Refugian Klaskanine siltstone tongue. This informal unit consists of thick bioturbated sandy siltstone and silty sandstone that is a lateral deep-marine correlative of the deltaic to shallow-marine Pittsburg Bluff Formation in the northeastern Coast Range. Discontinuous underthrusting of the Juan de Fuca oceanic plate at the base of the continental slope of the North American plate caused extensive uplift and subsidence along the Oregon continental margin throughout the Cenozoic (Snavely et al., 1980). Initiation of Oregon Coast Range uplift and accompanying erosion in the early Miocene, coupled with a global low stand of sea level (Vail and Mitchum, 1979), stripped most of the Oligocene (Zemorrian) Oswald West strata and in places much of the uppermost Eocene (upper Refugian) Oswald West strata in the field area, creating an unconformity. Deformation accompanying uplift included a system of east-west-trending, oblique-slip faults. The Pillarian-to-Newportian Astoria Formation unconformably overlies the Oswald West mudstone and reflects deposition offshore from an open, storm-dominated coast during an early-to-middle Miocene transgression. Deposition of the Big Creek sandstone and Silver Point mudstone members of the Astoria Formation was controlled in part by submarine paleotopography that developed as a result of early Miocene deformation of the Oswald West strata. The up to 200 meter thick Big Creek member varies from storm-deposited laminated sandstone to bioturbated mollusk-bearing silty sandstone that accumulated during fair weather conditions on the inner to middle shelf. Overlying and perhaps in part laterally equivalent to the Big Creek member is the up to 200 meter thick, deeper marine Silver Point member which consists of two lithologies: 1) interbedded, micaceous, turbidite sandstones and laminated mudstone; and 2) laminated bathyal mudstone that intertongues with and caps the turbidite sequences. The turbidite lithology is composed of two facies: 1) an underlying sand-rich facies, transitional between the shallow-marine Big Creek member and bathyal Silver Point strata, that was deposited on the outer shelf by storm-induced turbidity currents; and 2) an overlying sand-poor facies that was deposited at bathyal depths. The turbidite facies channelized, and at some places removed the underlying Big Creek member and were deposited directly over Oswald West mudstone. The Astoria depositional sequence ranges, from inner to outer neritic to bathyal facies and reflects continued deepening and anoxic depositional conditions of the Astoria basin through the middle Miocene. Big Creek and Silver Point sandstone petrology reflects volcanic sources from an ancestral western Cascades volcanic arc and metamorphic and granitic basement rocks farther east via an ancestral Columbia River drainage system. Diagenetic effects include: (a) formation of local calcite concretionary cements; and (b) formation of pore-filling smectite from alteration of volcanic rock fragments. At least six middle Miocene Columbia River Basalt intrusive episodes affected the Green Mountain-Young's River area soon after deposition of the Astoria Formation. These basalt sills and dikes include normally polarized and reversely polarized low Mg0 high TiO₂, low Mg0 low TiO₂, and high Mg0 Grande Ronde basalt chemical subtypes and two porphyritic Frenchman Springs Member basalts (Ginkgo and Kelly Hollow(?) petrologic types). These basalt intrusions are virtually indistinguishable, based on chemistry, from subaerial flows of the plateau-derived Columbia River Basalt Group subtypes at nearby Nicolai Mountain and Porter Ridge. This correlation supports the Beeson et al. (1979) hypothesis that the intrusions are not of local origin but formed by the invasion of the flows into the Miocene shoreline sediments to form "invasive" sills and dikes. Many dikes were emplaced along northeast- and northwest-trending faults, and some (i.e., Ginkgo) cut older sills (Grande Ronde). A laterally extensive Frenchman Springs sill occurs under an older widespread Grande Ronde sill. From this older over younger intrusive relationship, a mechanism of "invasion" of sediment from overlying lava flows is difficult to envision. A pulse of rapid subduction starting in the middle Miocene (Snavely et al., 1980) was accompanied by renewed uplift, intensive block faulting, and continued development of the earlier formed Coast Range uplift. Left-oblique northeast-trending faults and conjugate northwest-trending right-oblique faults offset Grande Ronde and Frenchman Springs dikes and sills. This conjugate fault pattern may reflect oblique east-west convergence between the North American and Juan de Fuca plates. The Silver Point mudstones and Oswald West mudstones have high total organic carbon contents, up to 5.5%, but are thermally immature and may act only as a source for biogenic gas(?) in the subsurface. Suitable reservoir rocks, such as the gas-producing upper Eocene Cowlitz Formation C & W sandstone, may pinch out before reaching the Green Mountain-Young's River area and are yet to be penetrated by exploration drilling. Post-middle Miocene fault traps abound in the area, although these faults might also breach subsurface natural gas reservoirs in the Green Mountain-Young's River area. Close

• 3177. [Article] The design, meaning, and use of the Turkish salon

  This exploratory study was focused on the design, meaning and use of the Turkish salon (the sitting room for guests). The findings provided an understanding of the different aspects of people's experiences ...

  Citation × Citation Citation Abstract Copy Title: The design, meaning, and use of the Turkish salon Author: Dazkir, Sibel Seda This exploratory study was focused on the design, meaning and use of the Turkish salon (the sitting room for guests). The findings provided an understanding of the different aspects of people's experiences of their salons. Socially and personally constructed meanings were examined to gain a deeper understanding of the respondents' perspectives. Thirty one respondents participated in the study. They were recruited from two cities in Turkey: Erbaa and Ankara. The data were collected in the respondents' salons via in-depth interviews, audio and video recordings, sketches, and observations. The interviews lasted from one to three and a half hours. The qualitative data analysis revealed themes which were grouped under three main categories: environment, person, and setting. Those interrelated dimensions were discussed in detail to have a better understanding of people's relationship with their salons. Environment related dimensions were conformity, influence of others, influence of changing socio-economic environment and rise of consumerism. Person related dimensions were satisfaction with the setting, interest in home decoration, demographics such as age and income level, personalization and meaningful objects, and place attachment. Setting related dimensions included physical characteristics of the setting such as color, size, and comfort, and use of the room such as how often and why they use the salon. The findings of this study supported the idea that consumption behaviors influence people's relationship with places. With the changing economic conditions, people live more comfortably, afford items easier, and there is more variety of products to reflect self or create the ideal salon environment compared to the past. Many respondents believed that rise in consumerism, spending unnecessarily, being allured by market pervasiveness, and being able to own products easily make people inappreciative, unhappy, and dissatisfied with what they have, and cause "israf" (wastefulness or prodigality). The respondents' narratives confirmed that they tried to create an environment that satisfied them; they cared about their salon designs. Some respondents revealed being influenced by trends and other people's salons indicating the influence of the market and others on salon design. A greater percentage of the respondents from Erbaa reported paying attention to others' salon designs compared to the respondents from Ankara. Although some spouses influenced the selection of furniture, women were more in charge of their salon designs than men. Having children influenced how often they used their salons, their purchase decisions, or when they would replace their furniture. Frequency and profile of the guests influenced use of their salons. The majority of the respondents from both Erbaa and Ankara displayed or revealed interest in home decoration through their effort to design and personalize their salons, their knowledge about furniture styles, paying attention to others' salons, watching home design TV shows, and visiting furniture stores as leisure activity. Socio-economic status influenced some of the respondents' salon designs regarding originality and price of their salon furniture and décor. Other factors such as their approach to consumerism, their taste, and family status influenced their salon design in a greater degree revealing the individualistic nature of domestic interiors. Although the findings provide insight on the relationship between demographic characteristics and salon design and use, the sampling method and sample size make it impossible to draw conclusions regarding the relationship between demographic characteristics and salon design and meaning. The respondents from both Erbaa and Ankara personalized the settings to reflect their self. They designed the rooms to reflect their taste, values, beliefs, culture, experiences, family, occupation, hobbies, and so forth. They displayed meaningful objects such as souvenirs, gifts, and family photographs. Personalization of the rooms provided control over the settings, a sense of connection to their salons, and sense of belonging. Physical characteristics of the setting, especially aesthetic appeal and usability influenced the respondents' satisfaction with the rooms. Although it was possible to observe patterns regarding the type of decorative items that they used, the meanings and stories behind how they acquired the objects made their design process unique and individualistic. The majority of respondents expressed sense of belonging and attachment to their salons and homes. Spending time in the setting, sharing the place with loved ones, feeling comfortable, sense of belonging, being satisfied with the setting, sense of freedom, reflecting own taste, personalization, and memories influenced the respondents' attachment to their salons in Ankara. The respondents from Erbaa added more intangible aspects to this list such as sincerity, happiness, coziness, effort in creating the room, familiarity, and feeling at peace. Exploring the meaning of place and objects in this study provided an understanding of everyday human life experience. This study provided rich information about the relationship between people and their salons. The findings indicated that design, meaning, and use of salons were shaped by the dynamic relationship between many individual, psychological, social, socio-cultural, socio-economic, and setting related variables. The findings confirmed that salons were designed by both personal and social point of view. The respondents created sense of place personally and socially. Studying the Turkish salon provided an understanding of how the socio-economic and socio-cultural changes were perceived by the respondents in their domestic space. The results indicate that political, cultural, religious, and economic environments influence society's perception of buying and decorating. Findings of this study contribute to different fields such as interior design by providing information on design process and design preferences of the respondents; industrial design by providing information on the meanings of objects, respondents' interaction with objects, and preferences for furniture and accessories; environmental psychology by providing information on how the respondents' behavior and emotions were influenced by the design of the setting and vice versa; and cultural anthropology by revealing information on the meanings of everyday life surroundings, and the influence of socio-cultural environment on salon creation. Title: The design, meaning, and use of the Turkish salon Author: Dazkir, Sibel Seda This exploratory study was focused on the design, meaning and use of the Turkish salon (the sitting room for guests). The findings provided an understanding of the different aspects of people's experiences of their salons. Socially and personally constructed meanings were examined to gain a deeper understanding of the respondents' perspectives. Thirty one respondents participated in the study. They were recruited from two cities in Turkey: Erbaa and Ankara. The data were collected in the respondents' salons via in-depth interviews, audio and video recordings, sketches, and observations. The interviews lasted from one to three and a half hours. The qualitative data analysis revealed themes which were grouped under three main categories: environment, person, and setting. Those interrelated dimensions were discussed in detail to have a better understanding of people's relationship with their salons. Environment related dimensions were conformity, influence of others, influence of changing socio-economic environment and rise of consumerism. Person related dimensions were satisfaction with the setting, interest in home decoration, demographics such as age and income level, personalization and meaningful objects, and place attachment. Setting related dimensions included physical characteristics of the setting such as color, size, and comfort, and use of the room such as how often and why they use the salon. The findings of this study supported the idea that consumption behaviors influence people's relationship with places. With the changing economic conditions, people live more comfortably, afford items easier, and there is more variety of products to reflect self or create the ideal salon environment compared to the past. Many respondents believed that rise in consumerism, spending unnecessarily, being allured by market pervasiveness, and being able to own products easily make people inappreciative, unhappy, and dissatisfied with what they have, and cause "israf" (wastefulness or prodigality). The respondents' narratives confirmed that they tried to create an environment that satisfied them; they cared about their salon designs. Some respondents revealed being influenced by trends and other people's salons indicating the influence of the market and others on salon design. A greater percentage of the respondents from Erbaa reported paying attention to others' salon designs compared to the respondents from Ankara. Although some spouses influenced the selection of furniture, women were more in charge of their salon designs than men. Having children influenced how often they used their salons, their purchase decisions, or when they would replace their furniture. Frequency and profile of the guests influenced use of their salons. The majority of the respondents from both Erbaa and Ankara displayed or revealed interest in home decoration through their effort to design and personalize their salons, their knowledge about furniture styles, paying attention to others' salons, watching home design TV shows, and visiting furniture stores as leisure activity. Socio-economic status influenced some of the respondents' salon designs regarding originality and price of their salon furniture and décor. Other factors such as their approach to consumerism, their taste, and family status influenced their salon design in a greater degree revealing the individualistic nature of domestic interiors. Although the findings provide insight on the relationship between demographic characteristics and salon design and use, the sampling method and sample size make it impossible to draw conclusions regarding the relationship between demographic characteristics and salon design and meaning. The respondents from both Erbaa and Ankara personalized the settings to reflect their self. They designed the rooms to reflect their taste, values, beliefs, culture, experiences, family, occupation, hobbies, and so forth. They displayed meaningful objects such as souvenirs, gifts, and family photographs. Personalization of the rooms provided control over the settings, a sense of connection to their salons, and sense of belonging. Physical characteristics of the setting, especially aesthetic appeal and usability influenced the respondents' satisfaction with the rooms. Although it was possible to observe patterns regarding the type of decorative items that they used, the meanings and stories behind how they acquired the objects made their design process unique and individualistic. The majority of respondents expressed sense of belonging and attachment to their salons and homes. Spending time in the setting, sharing the place with loved ones, feeling comfortable, sense of belonging, being satisfied with the setting, sense of freedom, reflecting own taste, personalization, and memories influenced the respondents' attachment to their salons in Ankara. The respondents from Erbaa added more intangible aspects to this list such as sincerity, happiness, coziness, effort in creating the room, familiarity, and feeling at peace. Exploring the meaning of place and objects in this study provided an understanding of everyday human life experience. This study provided rich information about the relationship between people and their salons. The findings indicated that design, meaning, and use of salons were shaped by the dynamic relationship between many individual, psychological, social, socio-cultural, socio-economic, and setting related variables. The findings confirmed that salons were designed by both personal and social point of view. The respondents created sense of place personally and socially. Studying the Turkish salon provided an understanding of how the socio-economic and socio-cultural changes were perceived by the respondents in their domestic space. The results indicate that political, cultural, religious, and economic environments influence society's perception of buying and decorating. Findings of this study contribute to different fields such as interior design by providing information on design process and design preferences of the respondents; industrial design by providing information on the meanings of objects, respondents' interaction with objects, and preferences for furniture and accessories; environmental psychology by providing information on how the respondents' behavior and emotions were influenced by the design of the setting and vice versa; and cultural anthropology by revealing information on the meanings of everyday life surroundings, and the influence of socio-cultural environment on salon creation. Close

• 3178. [Article] What's romance got to do with it? Sexual health outcomes of relationship dynamics among urban African American adolescents

  Urban African American adolescents exhibit high levels of risk behavior, disproportionately high rates of sexually transmitted infections (STIs), and are at risk for acquiring Human Immunodefiency Virus ...

  Citation × Citation Citation Abstract Copy Title: What's romance got to do with it? Sexual health outcomes of relationship dynamics among urban African American adolescents Author: Towner, Senna Lee Urban African American adolescents exhibit high levels of risk behavior, disproportionately high rates of sexually transmitted infections (STIs), and are at risk for acquiring Human Immunodefiency Virus (HIV). To date, interventions that address the high rates of STIs in this population demonstrate only moderate efficacy. As researchers strive to develop more effective interventions, social-ecological factors and developmental and gender issues are being considered. This study aimed to provide insight into the gendered characteristics of heterosexual urban African American adolescents' romantic relationships, and how these characteristics impact condom use. From a developmental standpoint, sexuality and romance are a normal part of adolescence. Thus, STI/HIV prevention targeted at urban African American youth can be improved if it considers romantic relationship dynamics, and how they influence sexual health behaviors including condom use. To this end, the current study examined the interconnection among interpersonal relationship factors including monogamy, commitment, trust, and respect, as well as intrapersonal relationship factors including gender and relationship history. Furthermore, this study examined how these inter- and intrapersonal factors impact youths' condom use behaviors. This research was guided by the existing literature, theoretical frameworks (i.e., the ecological perspective on health, Rusbult and Buunk's commitment theory, and Rotenberg and colleagues' trust framework), and the "directed perspective" (i.e., lens theory). A qualitative methodological approach was employed to collect data from 52 heterosexual, sexually experienced, African American adolescents (20 females; 32 males) ranging from 15-17 years in age at the time of enrollment. These youth resided in low-income neighborhoods of two large cities in the United States. Data from semi-structured interviews were analyzed using a phenomenological approach. Data analysis took place in four primary stages including: (a) development of case summaries; (b) development and refinement of codes and a codebook, and organization of data using matrices; (c) content analysis and reliability checks; and (d) reviews and critiques by, and discussions with, other research team members. Numerous themes and subthemes that provide insight into the multifaceted characteristics of urban African American adolescents' romantic relationships emerged. Findings show that study participants' romantic relationships were indeed characterized by gender-specific beliefs and behaviors, but that some beliefs and behaviors were similar across gender. For instance, males and females alike acknowledged positive feelings towards monogamy, trust, and respect, and they considered these dynamics as closely linked. That is, males and females viewed monogamy as indicative of commitment, and monogamous and committed relationships were those that were trusting and respectful. Youths' relationship experiences, however, contradicted their ideals to a great extent. For instance, despite the finding that males held positive perceptions of monogamy, they often engaged in multiple partnerships. This finding that shows young African American males’ often engage in multiple partnerships corroborates other research. Furthermore, these data provide insight into the social pressures experienced by urban African American males that encourage them to engage in multiple partnerships and remain uncommitted. According to the current findings, males' multiple partnerships set in motion a breakdown in relationship dynamics (i.e., lack of commitment, mistrust, disrespect), and thus youth experienced less-than ideal romantic relationships. Adolescents' less-than ideal experiences subsequently impacted their current and future romantic relationship beliefs and expectations. For instance, because males were frequently non-monogamous, females did not commonly express commitment to or trust in males. Despite this, only a few females talked about breaking up with a partner whom they mistrusted. Males, on the other hand, considered being monogamous and committed when they had negative experiences with being in multiple, uncommitted sexual partnerships. In addition, relationship dynamics, most noticeably trust (although trust was intricately linked to monogamy, commitment, and respect), impacted condom use. Although adolescents considered condom use important, males and females considered not using condoms when they were with a partner whom they trusted was monogamous and free from STIs. Furthermore, some male respondents talked about the need to balance the protection that condoms provided with the pleasure experienced when not using them. With casual and mistrusted partners, safety tended to take precedence; with more serious and trusted partners, pleasure tended to take precedence. Finally, these data elicited gender similarities and differences related to romantic respect perceptions. Across gender, respect was thought to be an important dynamic in romantic relationships, and one closely related to monogamy, commitment, and trust. Because beliefs about respect were interrelated with beliefs about other relationship dynamics that impacted condom use, respect may also impact condom use. The findings of this study suggest that youth have an understanding about how to develop healthy romantic relationships in adolescence and, in turn, healthy romantic relationships in adulthood. That said, respondents had little to no experience with being in healthy relationships. These study findings can help guide future research, and inform sexual health interventions. For example, investigators should explore further males' belief that monogamy is positive, as this belief frequently contradicted their related behavior (i.e., males often had multiple sexual partners). Finally, future interventions, including dyadic-level interventions, should focus on the dynamics of relationships. In doing so, the efficacy of STI/HIV prevention efforts targeted at African American youth may be enhanced. Title: What's romance got to do with it? Sexual health outcomes of relationship dynamics among urban African American adolescents Author: Towner, Senna Lee Urban African American adolescents exhibit high levels of risk behavior, disproportionately high rates of sexually transmitted infections (STIs), and are at risk for acquiring Human Immunodefiency Virus (HIV). To date, interventions that address the high rates of STIs in this population demonstrate only moderate efficacy. As researchers strive to develop more effective interventions, social-ecological factors and developmental and gender issues are being considered. This study aimed to provide insight into the gendered characteristics of heterosexual urban African American adolescents' romantic relationships, and how these characteristics impact condom use. From a developmental standpoint, sexuality and romance are a normal part of adolescence. Thus, STI/HIV prevention targeted at urban African American youth can be improved if it considers romantic relationship dynamics, and how they influence sexual health behaviors including condom use. To this end, the current study examined the interconnection among interpersonal relationship factors including monogamy, commitment, trust, and respect, as well as intrapersonal relationship factors including gender and relationship history. Furthermore, this study examined how these inter- and intrapersonal factors impact youths' condom use behaviors. This research was guided by the existing literature, theoretical frameworks (i.e., the ecological perspective on health, Rusbult and Buunk's commitment theory, and Rotenberg and colleagues' trust framework), and the "directed perspective" (i.e., lens theory). A qualitative methodological approach was employed to collect data from 52 heterosexual, sexually experienced, African American adolescents (20 females; 32 males) ranging from 15-17 years in age at the time of enrollment. These youth resided in low-income neighborhoods of two large cities in the United States. Data from semi-structured interviews were analyzed using a phenomenological approach. Data analysis took place in four primary stages including: (a) development of case summaries; (b) development and refinement of codes and a codebook, and organization of data using matrices; (c) content analysis and reliability checks; and (d) reviews and critiques by, and discussions with, other research team members. Numerous themes and subthemes that provide insight into the multifaceted characteristics of urban African American adolescents' romantic relationships emerged. Findings show that study participants' romantic relationships were indeed characterized by gender-specific beliefs and behaviors, but that some beliefs and behaviors were similar across gender. For instance, males and females alike acknowledged positive feelings towards monogamy, trust, and respect, and they considered these dynamics as closely linked. That is, males and females viewed monogamy as indicative of commitment, and monogamous and committed relationships were those that were trusting and respectful. Youths' relationship experiences, however, contradicted their ideals to a great extent. For instance, despite the finding that males held positive perceptions of monogamy, they often engaged in multiple partnerships. This finding that shows young African American males’ often engage in multiple partnerships corroborates other research. Furthermore, these data provide insight into the social pressures experienced by urban African American males that encourage them to engage in multiple partnerships and remain uncommitted. According to the current findings, males' multiple partnerships set in motion a breakdown in relationship dynamics (i.e., lack of commitment, mistrust, disrespect), and thus youth experienced less-than ideal romantic relationships. Adolescents' less-than ideal experiences subsequently impacted their current and future romantic relationship beliefs and expectations. For instance, because males were frequently non-monogamous, females did not commonly express commitment to or trust in males. Despite this, only a few females talked about breaking up with a partner whom they mistrusted. Males, on the other hand, considered being monogamous and committed when they had negative experiences with being in multiple, uncommitted sexual partnerships. In addition, relationship dynamics, most noticeably trust (although trust was intricately linked to monogamy, commitment, and respect), impacted condom use. Although adolescents considered condom use important, males and females considered not using condoms when they were with a partner whom they trusted was monogamous and free from STIs. Furthermore, some male respondents talked about the need to balance the protection that condoms provided with the pleasure experienced when not using them. With casual and mistrusted partners, safety tended to take precedence; with more serious and trusted partners, pleasure tended to take precedence. Finally, these data elicited gender similarities and differences related to romantic respect perceptions. Across gender, respect was thought to be an important dynamic in romantic relationships, and one closely related to monogamy, commitment, and trust. Because beliefs about respect were interrelated with beliefs about other relationship dynamics that impacted condom use, respect may also impact condom use. The findings of this study suggest that youth have an understanding about how to develop healthy romantic relationships in adolescence and, in turn, healthy romantic relationships in adulthood. That said, respondents had little to no experience with being in healthy relationships. These study findings can help guide future research, and inform sexual health interventions. For example, investigators should explore further males' belief that monogamy is positive, as this belief frequently contradicted their related behavior (i.e., males often had multiple sexual partners). Finally, future interventions, including dyadic-level interventions, should focus on the dynamics of relationships. In doing so, the efficacy of STI/HIV prevention efforts targeted at African American youth may be enhanced. Close

• 3179. [Article] Mixed-conifer forests of central Oregon : structure, composition, history of establishment, and growth

  The structure and composition of mixed-conifer forest (MCF) in central Oregon has been altered by fire exclusion and logging. The resulting increased density, spatial contagion, and loss of fire resistant ...

  Citation × Citation Citation Abstract Copy Title: Mixed-conifer forests of central Oregon : structure, composition, history of establishment, and growth Author: Merschel, Andrew G. The structure and composition of mixed-conifer forest (MCF) in central Oregon has been altered by fire exclusion and logging. The resulting increased density, spatial contagion, and loss of fire resistant trees decrease the resiliency of this ecosystem to fire, drought, and insects. The historical and current composition and structure of MCF are characterized by steep environmental gradients and a complex mixed-severity fire regime. This inherent variation makes it difficult to determine the magnitude of anthropogenic effects and set objectives for restoration and management. As a result, there is a lack of consensus regarding how MCF should be managed and restored across the landscape. My primary research objectives were to: (1) Characterize the current structure and composition of MCF and how these vary with environmental setting; and (2) Characterize establishment and tree growth patterns in MCF in different environmental settings. To address these objectives, I collected field data on structure and composition and increment cores across a range of environmental conditions in MCF of the eastern Cascades and Ochoco Mountains. I used cluster analysis to identify four stand types based on structure and composition in the eastern Cascades study area and four analogous types in the Ochoco Mountains study area. Variation in understory composition and the presence of large diameter shade tolerant species distinguish each type. Stand types occupied distinct environmental settings along a climatic gradient of increasing precipitation and elevation. At relatively dry PIPO sites understories were dominated by ponderosa pine. At wetter PIPO/PSME and PIPO ABGC sites understories were dominated by shade tolerant species, but ponderosa pine was dominant in the overstory. At the coolest and wettest PIPO/PSME/ABGC sites understories were dominated by grand fir and shade tolerant species were common in the overstory. In the eastern Cascades current density of all live trees and snags was 432, 461, 570, 372 trees per hectare (TPH) for the four stand types identified. Stand types in the drier Ochoco Mountains were currently less dense at 279, 304, 212, and 307 TPH. Current MCF densities in both areas are 2-3 times higher than densities estimated for the late 19th and early 20th centuries from other studies in those two areas. Reconstruction of cuts in each stand type indicates that the density of large diameter ponderosa pine has been reduced by approximately 50% in all stand types in both study regions. Age histograms demonstrate that current density and composition of MCF stand types is a product of abrupt increases in tree establishment following fire exclusion in the late 19th century. The number of trees established increased after 1900 in all stand types, but the timing and composition of changes in establishment varied with climate. At dry PIPO sites increases in establishment were delayed until the 1920s and 1930s and were composed of ponderosa pine. At PIPO/PSME and PIPO/ABGC sites with intermediate precipitation, establishment was dominated by ponderosa pine prior to 1900, but after 1900 establishment was dominated by a large pulse of Douglas-fir and grand fir. At the wettest PIPO/PSME/ABGC there was less evidence of changes in structure and composition over time. My results indicate that compared to dry pine and dry-mixed conifer sites, relatively productive moist mixed-conifer sites were characterized by large changes in structure and composition. Such sites could be considered more ecologically altered by lack of fire than drier forest types that had high fire frequencies but slower rates of stand development and less plant community change. Radial growth patterns of cored ponderosa pines differed between the eastern Cascades and Ochoco Mountains. In the eastern Cascades mean growth rates and variance decreased during favorable climatic periods after 1900. This is likely related to increased competition, and provides evidence that current stand density lacks a temporal analog in the 18th and 19th centuries. Sensitivity of growth to climate and harvest suggest competition for water in the denser forest of the eastern Cascades, and indicates thinning will increase the diameter growth rate of large old pines. In the Ochoco Mountains, ponderosa pine tree growth was less responsive to climate prior to fire exclusion in the late 1800s, and growth did not respond to fire events. This suggests competition among trees was historically low in this region. After fire exclusion growth became more responsive to wet and dry climatic cycles, which may indicate that increased density and competition made trees more responsive to climate variability. Patterns of slow and fast growth appeared to differ between study regions and likely differ at the sub-regional scale. Further analysis of the relationship between growth and climate in different environmental settings is needed to distinguish where stand development has been modified by disruption of fire regimes. Title: Mixed-conifer forests of central Oregon : structure, composition, history of establishment, and growth Author: Merschel, Andrew G. The structure and composition of mixed-conifer forest (MCF) in central Oregon has been altered by fire exclusion and logging. The resulting increased density, spatial contagion, and loss of fire resistant trees decrease the resiliency of this ecosystem to fire, drought, and insects. The historical and current composition and structure of MCF are characterized by steep environmental gradients and a complex mixed-severity fire regime. This inherent variation makes it difficult to determine the magnitude of anthropogenic effects and set objectives for restoration and management. As a result, there is a lack of consensus regarding how MCF should be managed and restored across the landscape. My primary research objectives were to: (1) Characterize the current structure and composition of MCF and how these vary with environmental setting; and (2) Characterize establishment and tree growth patterns in MCF in different environmental settings. To address these objectives, I collected field data on structure and composition and increment cores across a range of environmental conditions in MCF of the eastern Cascades and Ochoco Mountains. I used cluster analysis to identify four stand types based on structure and composition in the eastern Cascades study area and four analogous types in the Ochoco Mountains study area. Variation in understory composition and the presence of large diameter shade tolerant species distinguish each type. Stand types occupied distinct environmental settings along a climatic gradient of increasing precipitation and elevation. At relatively dry PIPO sites understories were dominated by ponderosa pine. At wetter PIPO/PSME and PIPO ABGC sites understories were dominated by shade tolerant species, but ponderosa pine was dominant in the overstory. At the coolest and wettest PIPO/PSME/ABGC sites understories were dominated by grand fir and shade tolerant species were common in the overstory. In the eastern Cascades current density of all live trees and snags was 432, 461, 570, 372 trees per hectare (TPH) for the four stand types identified. Stand types in the drier Ochoco Mountains were currently less dense at 279, 304, 212, and 307 TPH. Current MCF densities in both areas are 2-3 times higher than densities estimated for the late 19th and early 20th centuries from other studies in those two areas. Reconstruction of cuts in each stand type indicates that the density of large diameter ponderosa pine has been reduced by approximately 50% in all stand types in both study regions. Age histograms demonstrate that current density and composition of MCF stand types is a product of abrupt increases in tree establishment following fire exclusion in the late 19th century. The number of trees established increased after 1900 in all stand types, but the timing and composition of changes in establishment varied with climate. At dry PIPO sites increases in establishment were delayed until the 1920s and 1930s and were composed of ponderosa pine. At PIPO/PSME and PIPO/ABGC sites with intermediate precipitation, establishment was dominated by ponderosa pine prior to 1900, but after 1900 establishment was dominated by a large pulse of Douglas-fir and grand fir. At the wettest PIPO/PSME/ABGC there was less evidence of changes in structure and composition over time. My results indicate that compared to dry pine and dry-mixed conifer sites, relatively productive moist mixed-conifer sites were characterized by large changes in structure and composition. Such sites could be considered more ecologically altered by lack of fire than drier forest types that had high fire frequencies but slower rates of stand development and less plant community change. Radial growth patterns of cored ponderosa pines differed between the eastern Cascades and Ochoco Mountains. In the eastern Cascades mean growth rates and variance decreased during favorable climatic periods after 1900. This is likely related to increased competition, and provides evidence that current stand density lacks a temporal analog in the 18th and 19th centuries. Sensitivity of growth to climate and harvest suggest competition for water in the denser forest of the eastern Cascades, and indicates thinning will increase the diameter growth rate of large old pines. In the Ochoco Mountains, ponderosa pine tree growth was less responsive to climate prior to fire exclusion in the late 1800s, and growth did not respond to fire events. This suggests competition among trees was historically low in this region. After fire exclusion growth became more responsive to wet and dry climatic cycles, which may indicate that increased density and competition made trees more responsive to climate variability. Patterns of slow and fast growth appeared to differ between study regions and likely differ at the sub-regional scale. Further analysis of the relationship between growth and climate in different environmental settings is needed to distinguish where stand development has been modified by disruption of fire regimes. Close

• 3180. [Article] Genesis of some soils in the central western Cascades of Oregon

  Soils representative of several landscape units in the H. J. Andrews Experimental Forest, Western Cascade Range, were sampled, analyzed, and tentatively classified. Genetic inferences were drawn relating ...

  Citation × Citation Citation Abstract Copy Title: Genesis of some soils in the central western Cascades of Oregon Author: Brown, R. B. Soils representative of several landscape units in the H. J. Andrews Experimental Forest, Western Cascade Range, were sampled, analyzed, and tentatively classified. Genetic inferences were drawn relating soils to landscape position and other factors of soil formation. Descriptive information and nutrient capital data were provided to support ecosystem modelling efforts by the Coniferous Forest Biome study group of the U. S./International Biological Program (IBP). To meet the "nutrient capital" requirements of IBP, and to gain insight particularly into the effects of coarse fragments on soil genesis, a volumetric approach was used. Soil organic matter, total N, extractable P, exchangeable cations, free Fe oxides, and cation exchange capacity were expressed in terms of weight or equivalents per unit volume of "whole soil," defined as organic and mineral fine earth components plus pore space plus coarse fragments. The various entities, in grams or equivalents per liter of whole soil, were observed as to their variation with depth. Additional calculations showed levels of the various entities per surface meter ³ of whole soil. Soil temperature data from several sites within the Andrews Forest showed the mesic-frigid soil temperature regime boundary to fall at about the 600 m (2, 000 ft) elevation on south slopes and at about the 450 m (1, 500 ft) elevation on north slopes. The frigidcryic boundary apparently was above the 1, 500 m (4,900 ft) elevation in the Andrews Forest. A sequence of three fluvial and two colluvial soils ranging in elevation from 440 to 460 m was studied in conjunction with concurrent IBP investigations into the geomorphic history of the area The soil on a floodplain adjacent to Lookout Creek, in the sandy-skeletal, mixed, mesic family of Fluventic Hapludolls, was between 500 and 7, 000 yrs in age. The adjacent stream terrace soil, in the loamyskeletal, mixed, mesic family of Fluventic Dystrochrepts, was > 7, 000 yrs old as evidenced Mazama pumice erposi tE-; on or near the surface of the terrace. Volumetric analysis suggested that the floodplain soil had a mollic epipedon largely by virtue of its high content of coarse fragments. The coarse fragments caused a concentration of soil organic matter and recycled cations into a smaller volume of fine earth as compared with the terrace soil, which was lower in coarse fragments. An alluvial-colluvial fan emanated from an adjacent slope and lapped onto the terrace. The soil in this fan was a member of the Fluventic Eutrochrepts, loamy-skeletal, mixed, mesic. It was high in base status and moderately high in clay content, apparently because the southeast-facing source area for parent material here had experienced only shallow weathering and minimal leaching. Across Lookout Creek from these landscape units was a remnant of a high colluvial terrace emanating from a northwest-facing watershed. At the crest of this fan remnant the soil was a member of the loamy-skeletal, mixed, mesic family of Fluventic Dystrochrepts with a distinct layer of Mazama pumice at the 75 to 85 cm depth. This terrace is cut by the watershed stream, which has deposited a comparatively well sorted fan. Soils are in the coarseloamy, mixed, mesic family of Fluventic Dystrochrepts, Eight landscape units in longitudinal and transverse crosssections of upper McRae Creek valley, ranging in elevation from 800 to 1, 200 m, were chosen to study upland soil genesis. Proceeding up the valley, stage of profile development appeared to decrease, indicating a series of depositional events. Soils varied from Eutric Glossoboralfs, fine, mixed on the lowermost surface to Fluventic Dystrochrepts, fine-loamy, mixed, frigid on the next higher surface, to Fluventic Dystrochrepts, loamy-skeletal, mixed, frigid on the next higher surface, to Typic Haplumbrepts, loamy-skeletal, mixed, frigid on the backslope at the valley headwall. The two lowermost soils contrasted markedly with the two uppermost soils, being lower in content of organic matter and N, and higher in base status and clay content. The upper two soils, typical of upper valley bottom and sideslope soils in the region, were extremely low in exchangeable bases and base saturation as measured at pH 7. Compared with the two lower soils, however, these upper soils had relatively high soil: water pH values and relatively small drops in pH from soil:water to soil :KCI measurement. This may be an indication that the upper soils were higher in amorphous content. Greater pH-dependent-CEC would have caused the upper soils to exhibit unrealistically high CEO s--and thus low base saturations--when measured at pH 7. A topoclimosequence of soils on north, east (saddle), and south-facing landscape units with a single parent rock lithology was studied in the transverse valley transect. All three soils were placed tentatively in the Andic Dystrochrepts. The north-facing soil was in a medial - skeletal, frigid family, was the deepest to bedrock ( > 1 1/2 m), aria had the freshest coarse fragments of the three soils. The saddle and south-facing soils were in medial-skeletal, frigid and medial, frigid families, respectively. They were shallow ( <1 m) to saprolite bedrock, with well weathered coarse fragments in the regolith, demonstrating shallower, but apparently more intense weathering on the more exposed sites. These more exposed soils were darker in color than the north-facing soil. Soil organic matter levels were not strikingly different among the three soils. Soil N levels were significantly higher in the south-facing soil than in the east and north-facing soils. Levels of exchangeable bases, while low, were not as low in these three soils as in the upper valley bottom and backslope soils. Saprolite horizons had higher base saturations than overlying horizons. Title: Genesis of some soils in the central western Cascades of Oregon Author: Brown, R. B. Soils representative of several landscape units in the H. J. Andrews Experimental Forest, Western Cascade Range, were sampled, analyzed, and tentatively classified. Genetic inferences were drawn relating soils to landscape position and other factors of soil formation. Descriptive information and nutrient capital data were provided to support ecosystem modelling efforts by the Coniferous Forest Biome study group of the U. S./International Biological Program (IBP). To meet the "nutrient capital" requirements of IBP, and to gain insight particularly into the effects of coarse fragments on soil genesis, a volumetric approach was used. Soil organic matter, total N, extractable P, exchangeable cations, free Fe oxides, and cation exchange capacity were expressed in terms of weight or equivalents per unit volume of "whole soil," defined as organic and mineral fine earth components plus pore space plus coarse fragments. The various entities, in grams or equivalents per liter of whole soil, were observed as to their variation with depth. Additional calculations showed levels of the various entities per surface meter ³ of whole soil. Soil temperature data from several sites within the Andrews Forest showed the mesic-frigid soil temperature regime boundary to fall at about the 600 m (2, 000 ft) elevation on south slopes and at about the 450 m (1, 500 ft) elevation on north slopes. The frigidcryic boundary apparently was above the 1, 500 m (4,900 ft) elevation in the Andrews Forest. A sequence of three fluvial and two colluvial soils ranging in elevation from 440 to 460 m was studied in conjunction with concurrent IBP investigations into the geomorphic history of the area The soil on a floodplain adjacent to Lookout Creek, in the sandy-skeletal, mixed, mesic family of Fluventic Hapludolls, was between 500 and 7, 000 yrs in age. The adjacent stream terrace soil, in the loamyskeletal, mixed, mesic family of Fluventic Dystrochrepts, was > 7, 000 yrs old as evidenced Mazama pumice erposi tE-; on or near the surface of the terrace. Volumetric analysis suggested that the floodplain soil had a mollic epipedon largely by virtue of its high content of coarse fragments. The coarse fragments caused a concentration of soil organic matter and recycled cations into a smaller volume of fine earth as compared with the terrace soil, which was lower in coarse fragments. An alluvial-colluvial fan emanated from an adjacent slope and lapped onto the terrace. The soil in this fan was a member of the Fluventic Eutrochrepts, loamy-skeletal, mixed, mesic. It was high in base status and moderately high in clay content, apparently because the southeast-facing source area for parent material here had experienced only shallow weathering and minimal leaching. Across Lookout Creek from these landscape units was a remnant of a high colluvial terrace emanating from a northwest-facing watershed. At the crest of this fan remnant the soil was a member of the loamy-skeletal, mixed, mesic family of Fluventic Dystrochrepts with a distinct layer of Mazama pumice at the 75 to 85 cm depth. This terrace is cut by the watershed stream, which has deposited a comparatively well sorted fan. Soils are in the coarseloamy, mixed, mesic family of Fluventic Dystrochrepts, Eight landscape units in longitudinal and transverse crosssections of upper McRae Creek valley, ranging in elevation from 800 to 1, 200 m, were chosen to study upland soil genesis. Proceeding up the valley, stage of profile development appeared to decrease, indicating a series of depositional events. Soils varied from Eutric Glossoboralfs, fine, mixed on the lowermost surface to Fluventic Dystrochrepts, fine-loamy, mixed, frigid on the next higher surface, to Fluventic Dystrochrepts, loamy-skeletal, mixed, frigid on the next higher surface, to Typic Haplumbrepts, loamy-skeletal, mixed, frigid on the backslope at the valley headwall. The two lowermost soils contrasted markedly with the two uppermost soils, being lower in content of organic matter and N, and higher in base status and clay content. The upper two soils, typical of upper valley bottom and sideslope soils in the region, were extremely low in exchangeable bases and base saturation as measured at pH 7. Compared with the two lower soils, however, these upper soils had relatively high soil: water pH values and relatively small drops in pH from soil:water to soil :KCI measurement. This may be an indication that the upper soils were higher in amorphous content. Greater pH-dependent-CEC would have caused the upper soils to exhibit unrealistically high CEO s--and thus low base saturations--when measured at pH 7. A topoclimosequence of soils on north, east (saddle), and south-facing landscape units with a single parent rock lithology was studied in the transverse valley transect. All three soils were placed tentatively in the Andic Dystrochrepts. The north-facing soil was in a medial - skeletal, frigid family, was the deepest to bedrock ( > 1 1/2 m), aria had the freshest coarse fragments of the three soils. The saddle and south-facing soils were in medial-skeletal, frigid and medial, frigid families, respectively. They were shallow ( <1 m) to saprolite bedrock, with well weathered coarse fragments in the regolith, demonstrating shallower, but apparently more intense weathering on the more exposed sites. These more exposed soils were darker in color than the north-facing soil. Soil organic matter levels were not strikingly different among the three soils. Soil N levels were significantly higher in the south-facing soil than in the east and north-facing soils. Levels of exchangeable bases, while low, were not as low in these three soils as in the upper valley bottom and backslope soils. Saprolite horizons had higher base saturations than overlying horizons. Close