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521. [Article] Dietary behavior and body composition parameters among self-reported exercising and non-exercising elderly women
The percentage of the American population who are 65 years old or older is rapidly increasing, especially the proportion of women. It is becoming crucial to encourage lifestyle behaviors that will enable ...Citation Citation
- Title:
- Dietary behavior and body composition parameters among self-reported exercising and non-exercising elderly women
- Author:
- Bell, Kathleen A.
The percentage of the American population who are 65 years old or older is rapidly increasing, especially the proportion of women. It is becoming crucial to encourage lifestyle behaviors that will enable senior women to remain in optimal health. Following the 1990 Dietary Guidelines' recommendations to limit fat intake and consume adequate amounts of dietary fiber has been shown to positively impact longevity and health status in the elderly by decreasing risk factors for chronic diseases. An expected outcome of engaging in regular exercise is a reduction in body fat, which is also associated with a lowered incidence of several chronic illnesses. However, the literature clearly indicates that nutritional quality of the diet and involvement in regular exercise decrease with increasing age. There is evidence that, with the adoption of one health enhancing behavior, there is a greater tendency to engage in other health promoting behaviors, but little data exist on the healthseeking behaviors of older adults. The purpose of this study was to ascertain if there were identifiable differences between self-defined exercising and self-defined non-exercising elderly women with respect to their nutrient intake, food sources of dietary fat and fiber, dietary change behavior, and body composition parameters, considering their age and education and income levels. The objective was to determine whether those women who had consciously undertaken a regular exercise program would also have higher micronutrient intakes, make lower fat and higher fiber food choices, report having made more dietary changes in the direction of the 1990 Dietary Guidelines, and have leaner body compositions than those who had not undertaken such a program. Thirty-three elderly women self-reported exercisers (mean age 74.1 years) and 30 self-reported non-exercisers (mean age 71.3 years) were enrolled in a 14 week study. Exercisers were defined as those who reported having engaged in a regular program of planned exercise a minimum of 15 minutes per session, 2 times per week, for at least the last year, and non-exercisers were those who had not. They kept three, 7-day food records at 5 week intervals. Nutrient intake was estimated from 9 days of food records, 3 predetermined days from each recording period, using the Food Processor n software. Dietary intakes were analyzed for energy, macronutrients, dietary fiber, and selected micronutrients. Food sources of dietary fat and fiber were determined using a food categorization adapted from Popkin and coworkers (1989). Information concerning dietary change behavior, obtained from questionnaire responses, was compared between groups using chisquare tests. Body composition, assessed through repeat measurements during each dietary recording period, included determination of percent body fat through skinfolds, waist-to-hip-ratio and body mass index. Average 9-day nutrient intakes and anthropometric measures were compared between groups using t-tests or Mann- Whitney U tests. Both elderly women exercisers and non-exercisers had similar energy, macronutrient, and dietary fiber intakes based on 9-day means. Their total fat intakes, expressed in grams and as percentages of energy, were not significantly different. Both groups consumed a lower percentage of their daily kcalories as total fat (32%) compared with national surveys of women over 65 (36%). Exercisers consumed more total vitamin A (p=.03) and carotene (p=.00) than the non-exercising women. A great proportion of both groups did not meet 75 % of the Recommended Dietary Allowances for calcium and zinc. A larger proportion of the exercisers than the non-exercisers reported using lower fat cheese (p=.02) and green and yellow vegetables (p=.03), which partially explained their higher total vitamin A and carotene intakes. Exercisers obtained less of their total fat intake from lower fat milk (p=.02) and more of their fat intake from lower fat lunch meats (p=.04) than the non-exercisers. The categories of legumes (p=.02) and lower fiber vegetables (p=.05) supplied greater amounts of dietary fiber for the exercisers compared with the non-exercisers. When asked about dietary changes made over the past decade, a greater percentage of the exercisers than non-exercisers reported having decreased red meat intake (p=.05) and increased consumption of cereals (p=.05) and legumes (p=.00). Actual intake data showed that the legume food category contributed more dietary fiber to the diets of the exercisers than the non-exercisers (p=.02). No differences were found in body fat measures between the exercisers and non-exercisers. The lack of observed differences between the two groups reinforces what other researchers have found, that a large number of factors influence body composition, of which exercise is only one. More research is needed to distinguish the interactions of age, energy intake, and physical activity on the body fatness of elderly women, as well as the most accurate instruments for assessing body composition for this age group. Exercise participation among elderly women in this study appeared to be associated with several positive dietary behaviors. Elderly women exercisers compared to non-exercisers made food choices leading to higher total vitamin A and carotene intakes, and also reported making more changes in food consumption behaviors in the direction of current dietary recommendations. These observed outcomes provide support for designing health-promotion programs for elderly women which include both nutrition education and exercise components.
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To date, the use of oceanographic data in fisheries management has been limited by the scarcity and the difficulty of accessing complete oceanographic datasets. Consequently, fish stocks are managed with ...
Citation Citation
- Title:
- Integration of oceanographic information off the Washington and Oregon coasts into west coast groundfish ecology and fisheries management
- Author:
- Juan Jorda, Maria Jose
To date, the use of oceanographic data in fisheries management has been limited by the scarcity and the difficulty of accessing complete oceanographic datasets. Consequently, fish stocks are managed with limited knowledge about the habitat where fish live and incomplete understanding of what oceanographic conditions affect their populations. With the long-term goal to improve science for ecosystem-based management of the West Coast groundfish fishery, this study had three objectives. First, the assembling and merging of disperse oceanographic datasets for temperature, salinity, chlorophyll-a and current velocity from the 1930s to the year 2004 off the Washington and Oregon coasts. Second, the generation of oceanographic data products relevant for fisheries research, consisting of the computation and the plotting of climatological monthly means, standard deviations and coefficients of variation for a variety of ocean variables at several depths. Third, the development of an exploratory example of how oceanographic information collected in this study can be of use to improve the science and management of groundfish. Thus, a study was developed to investigate if groundfish distribution and abundances are associated with any ocean habitat or individual oceanographic variables, using a combination of univariate, classification and ordination techniques. The fish data were derived from a routine bottom trawl survey conducted by the National Oceanic and Atmospheric Administration Northwest Fisheries Science Center (NOAA-NWFSC). Five ocean habitats with distinct physical and biological characteristics were identified off the Washington and Oregon coast: Offshore Habitat, Upwelling Habitat, Highly Variable Upwelling Habitat, River Plume Habitat, and Highly Variable Habitat. These ocean habitats were characteristic of cold-regime summer upwelling conditions. Overall, the analyses suggested that the species composition differ among the five ocean habitats. Some species were highly indicative of some habitats; however, overall the associations were weak due to the high degree of overlap of ocean habitats in terms of species composition. All the analyses were consistent in associating shallower species with the shallowest habitats (the Highly Variable, River Plume and Upwelling habitats) and the deeper species with the deeper habitats (the Offshore and the Highly Variable Upwelling habitats), suggesting that groundfish are adapted to wide environmental ranges. In addition, the overall abundance and diversity of groundfish was higher in the shallower habitats. In contrast, groundfish species showed strong associations with individual environmental factors, primarily depth, surface chlorophyll-a, and salinity and temperature at the bottom of the seafloor, indicating that groundfish distributions are mainly organized along depth gradients. Latitudinal variations in upwelling intensity, river discharge and productivity along the coast were also important factors influencing shallow species distributions and abundances. For example, three regions with high chlorophyll-a concentrations were associated with large abundances of specific groundfish species. These regions were found over Heceta Bank, over the Juan de Fuca canyon and in the Columbia River Plume. This study began with the assembly of several ocean variables and the development of some preliminary ocean data products relevant to fisheries studies. However, the addition of other ocean variables, such as dissolved oxygen, and the computation of new ocean products, such as mixed-layer depth, and thermocline depth and strength, would be valuable. Future work should involve more interdisplinary studies between fisheries and oceanography, the integration of oceanographic information off the west coast of the U.S., and the collection of concurrent ocean data at each fish trawl location.
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523. [Article] Landscape-Level Approaches to Desert Bighorn Sheep (Ovis canadensis nelsoni) Conservation in a Changing Environment
Landscape characteristics can strongly influence demographic and genetic processes in wildlife populations. Climate change and human land use are causing many landscapes to change rapidly, and the effects ...Citation Citation
- Title:
- Landscape-Level Approaches to Desert Bighorn Sheep (Ovis canadensis nelsoni) Conservation in a Changing Environment
- Author:
- Creech, Tyler Graydon
Landscape characteristics can strongly influence demographic and genetic processes in wildlife populations. Climate change and human land use are causing many landscapes to change rapidly, and the effects on wildlife populations must be understood to properly manage these threats and design effective conservation strategies. In this dissertation, I explored the implications of landscape heterogeneity for desert bighorn sheep (Ovis canadensis nelsoni), an ecologically and culturally important ungulate species in the southwestern United States, and demonstrated new approaches that can be applied to landscape-level conservation of many wildlife species in changing landscapes. This research focused on populations within and surrounding U.S. national parks, comprising a large portion of the desert bighorn sheep's geographic range, and utilized a genetic dataset including > 1,600 individuals that was developed during this and previous projects. Landscape resistance models have been used extensively to predict potential linkages among fragmented wildlife populations, including desert bighorn sheep, but have rarely been used to guide systematic decision-making such as prioritizing conservation actions to maximize regional connectivity. In Chapter 1, I combined network theory and landscape resistance modeling to prioritize management for connectivity, including protection and restoration of dispersal corridors and habitat patches, in a desert bighorn sheep metapopulation in the Mojave Desert. I constructed network models of genetic connectivity (potential for gene flow) and demographicconnectivity (potential for colonization of empty habitat patches). I found that the type of connectivity and the network metric used to quantify had substantial effects on prioritization results; however, I was able to identify high-priority habitat patches and corridors that were highly ranked across all combinations of the above factors. Potential diet quality varies across landscapes and through time for desert bighorn sheep and other ungulates, but is difficult to measure at fine spatial and temporal resolution using traditional field-based methods. The remotely sensed vegetation index NDVI can potentially overcome these limitations, but its relationship to diet quality has never been empirically validated for desert herbivores. In Chapter 2, I examined how strongly NDVI was associated with diet quality of desert bighorn sheep in the Mojave Desert using fecal nitrogen data from multiple years and populations, and considered the effects of temporal resolution, geographic variability, and NDVI spatial summary statistic. I found that NDVI was more reliably associated with diet quality over the entire growing season than with instantaneous diet quality for a population, and was positively associated with population genetic diversity (a proxy for long-term diet quality). Although NDVI was a useful diet quality indicator for Mojave Desert bighorn sheep, my analysis suggested that it may be unreliable if satellite data are too spatially coarse to detect microhabitats providing high-quality forage, or if diet is strongly influenced by forage items that are weakly correlated with landscape greenness. Landscape genetic studies typically rely on neutral genetic markers to explore gene flow and genetic variation, but the potential for species to adapt to changing landscapes depends on how natural selection influences adaptive genetic variation. In Chapter 3, I optimized landscape resistance models for desert bighorn sheep in three regions with different landscape characteristics, and then used genetic simulations incorporating natural selection to determine how the spread of adaptive variation is influenced by differences among landscapes. Optimized landscape resistance models differed between regions but slope, presence of water barriers, and major roads had the greatest impacts on gene flow. Differences among landscapes strongly influenced the spread of adaptive genetic variation, with faster spread in landscapes with more continuously distributed habitat and when a pre-existing allele (i.e., standing genetic variation) rather than a novel allele (i.e., mutation) served as the source of adaptive genetic variation. Climate change presents a substantial threat to desert bighorn sheep and wildlife worldwide, and adaptation may be required to persist in novel environmental conditions. Knowledge of how adaptive capacity - the potential to cope with climate change by persisting in situ or moving to more suitable ranges or microhabitats - varies across populations is needed to establish conservation priorities for minimizing climate change impacts to individual species. In Chapter 4, I explored variation in the evolutionary component of adaptive capacity for 62 desert bighorn sheep populations on and near U.S. national parks. I measured adaptive capacity of populations as a function of two factors that are strongly associated with the potential for evolutionary adaptation, genetic diversity and connectivity (estimated using a landscape resistance model from Chapter 3). Genetic diversity and connectivity were highly variable across regions and populations. I identified populations with high adaptive capacity that could serve as genetic refugia from climate change impacts (e.g., those in Death Valley and Grand Canyon National Parks), but also populations with low adaptive capacity that may require conservation actions to improve their potential for adaptation (e.g., those in eastern Utah and the southern Mojave Desert). Genetic structure analyses suggested that populations in eastern Utah were genetically distinct from the rest of the study area, likely resulting from restricted gene flow following regional population extinctions. This dissertation highlighted the effects of landscape heterogeneity on genetic and demographic processes in desert bighorn sheep populations. Collectively, the information in these chapters should help guide management of desert bighorn sheep in the face of climate change and human land use. The landscape-level approaches demonstrated here may be useful for managing many other wildlife species.
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524. [Article] Succession functions of forest pathogens and insects : ecosections M332a and M333d in northern Idaho and western Montana ; summary
We analyzed the effects of pathogens and insects on forest succession in the absence of fire or management, addressing a number of related questions: 1. What is the rate of change in such forests? 2. How ...Citation Citation
- Title:
- Succession functions of forest pathogens and insects : ecosections M332a and M333d in northern Idaho and western Montana ; summary
- Author:
- United States. Forest Service. Northern Region. State & Private Forestry, Hagle, Susan K., Byler, James W., United States. Forest Health Protection
We analyzed the effects of pathogens and insects on forest succession in the absence of fire or management, addressing a number of related questions: 1. What is the rate of change in such forests? 2. How significant are the roles of pathogens and insects in the forest change? 3. How do pathogens and insects influence forest succession? Vegetation change was measured using a geographic information system (GIS) analysis method that overlaid 1935-era and 1975-era maps of sample subcompartments on national forest land in two ecoregions in northern Idaho and western Montana. This 40-year period was, coincidentally, the time in which white pine blister rust became epidemic and in which fire suppression policies were implemented. Stand hazard ratings were used to classify stand susceptibility to insects and most pathogens; root disease severity was rated from aerial photographs. We considered an insect or pathogen to be a cause of successional change when the following conditions were met: the insect or disease hazard or severity rating for a cover type/structure stage class was high or moderate; a transition from one class to another was consistent with the expected function of the agent; and the change was not explained by advancing succession in the absence of pathogen or insect influence. We found high rates of change from pathogens and insects in forests that had no evidence of recent active management or fire. More than 90 percent of the sample stands changed to a different cover type, structure stage, or both during the 40-year period. Insects and pathogens were associated with 75 percent or more of that change. Root pathogens, white pine blister rust, and bark beetles were the cause of most of the observed changes. The most significant pathogen and insect influences on cover type were to accelerate succession of western white pine, ponderosa pine, and lodgepole pine to later successional, more shade-tolerant species. The effects on structure were to reduce stand density or prevent canopy closure. Grand fir, Douglasfir, and subalpine fir were the predominant cover types at the end of the period, and were highly susceptible to root diseases, bark beetles, fire, and drought. The trend toward mature, dense, climax forest is projected to decrease substantially during the next 40 years, with greater accumulations occurring in low-density mature and younger pole-sized stands that result from root disease- and bark beetle-caused mortality. Our results underscore the relevance of pathogens and insects to forest planning and forest management. The introduction of white pine blister rust has drastically and perhaps permanently altered succession in this once-significant type. In the absence of fire or management, native pathogens, and insects continue to bring about change in forest composition and structure. This change is different from that produced by fire, as early seral species are usually not regenerated as a result of pathogen or insect activity. The ecological outcomes of pathogen and insect activities are sometimes desirable and sometimes not desirable. We should consider whether or not their effects create desired conditions for the landscape in deciding whether or not to alter their influence through management. This information on long-term effects of pathogens and insects on succession can be used to address forest health in forest plans, to analyze alternative actions, and to more accurately communicate outcomes of those alternatives to various stakeholders. We found that pathogens and insects can have large effects on forest succession. The economic impacts of pathogens and insects have been well documented; with this analysis, we have begun to understand and quantify their successional effects.
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525. [Article] Baseline stream chemistry and soil resources for the Hinkle Creek Research and Demonstration Area Project
This research addressed the opportunity to obtain baseline data for both stream chemistry and soil resources for an intensively managed forest watershed, encompassed by the North and South Forks of Hinkle ...Citation Citation
- Title:
- Baseline stream chemistry and soil resources for the Hinkle Creek Research and Demonstration Area Project
- Author:
- George, Robert Lance
This research addressed the opportunity to obtain baseline data for both stream chemistry and soil resources for an intensively managed forest watershed, encompassed by the North and South Forks of Hinkle Creek Watershed Research and Demonstration Area Project near Sutherlin, Oregon. A solid representative database for both stream and soil nutrients in these forest watersheds will provide a model upon which to help gauge the effects of current and expected intensive forest management practices on industrial forest land. Eight original sampling points were described for water chemistry. In addition, samples were collected from three other locations directly below two clearcuts completed in 2001 that had subsequent intensive vegetation control measures in place. The total nutrient output in kg month [superscript -1] and kg ha [superscript -1] month [superscript -1] among the Hinkle Creek streams differed greatly due to discharge and watershed area, but their nutrient concentrations, with few exceptions, were closely related. All stream water N concentrations were low, except for some higher NO3-N concentrations for two partially treated watersheds, Clay and Beeby Creeks. DeMearsman Creek, a control, had an NO3-N + NO2-N concentration of 0.01mg L [superscript -1] in December, 2003. In contrast, a Beeby Creek tributary below a clearcut had a 1.75 mg L [superscript -1] concentration. The NO3-N concentrations increased substantially after urea fertilization of most of the Hinkle Creek basin in late October, 2004. Samples in January, 2005 showed a reversal of NO3-N + NO2-N concentrations between treatment vs. control watersheds (P < 0.02, T = 4.24). Partial clearcuts or completely forested basins both had similar nutrient concentration data, with the exception of N, especially NO3-N + NO2-N. Beeby Creek was significantly higher in NO3-N + NO2-N, with a two-sided inference (P < 0.0001, T = 6.2-6.5), than all of the other headwater streams. Clay Creek sampled above and below a clearcut showed no significant change (P = 0.272, T = 1.15). Hinkle Creek South Fork showed that the downstream effects of clearcutting, especially NO3-N + NO2-N output from smaller upstream tributaries, may transmit their effects to larger confluences downstream (P = 0.0001, T = 4.47). Newly published soil surveys from the National Resource Conservation Service and Douglas County SCS were used to set up a methodology for sampling the representative Hinkle Creek soil resources. Eight main soil types were mapped, 27 representative soil pits were dug in accordance with the location of the mapped soils, and standard soil survey descriptions were created. Soil cores were taken from different depths (0-15, 15-30 and 30-60 cm). These data were used to estimate total soil C, N, P, and S resources, soil cation exchange capacity, and available base cations (Ca, Mg, K, and Na). Soil N was low, with the most prevalent soil series, (Orford Gravelly Loam) having 1010 kg ha [superscript -1] (S.E. 143) in the top 15 cm. Low stream N concentration may be correlated with the low soil N content, which may limit Hinkle Creek tree production.
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526. [Article] Biological soil crusts in forested ecosystems of southern Oregon : presence, abundance and distribution across climate gradients
In arid and semi-arid deserts, soils are commonly covered with biological soil crusts. The study of arid biocrusts and their ecological function has become increasingly common in the literature over the ...Citation Citation
- Title:
- Biological soil crusts in forested ecosystems of southern Oregon : presence, abundance and distribution across climate gradients
- Author:
- Olarra, Jennifer A.
In arid and semi-arid deserts, soils are commonly covered with biological soil crusts. The study of arid biocrusts and their ecological function has become increasingly common in the literature over the last several decades. Interestingly, no mention is made of biological soil crusts in forested ecosystems, raising the question as to whether they exist in these areas and if they do, why they have yet to be recognized as such? Through the use a parallel logic, this study finds that biocrusts do indeed exist in forests, a novel relationship in forest ecology and seeks to determine if there exist ecophysical explanations for the abundance and distribution throughout the forest landscape. This study examined the effects of climate variables and substrate types on the abundance, distribution and overall cover of forest soil biocrust at fifty-two sites in southern Oregon, U.S.A. Sites were randomly selected within established buffer zones in the Siuslaw, Rogue-Sisikyou, Umpqua, and Fremont-Winema National Forests. The methods of Belnap et al 2001 were tested and then modified for application in forested ecosystems. Data were collected on the relative abundance and distribution of biocrust morphological groups across available substrates, community biocrust morphology, aspect, elevation and soil texture, pH and organic matter content. Site-specific data on average annual precipitation and minimum/maximum temperatures was collected using the PRISM Climate Model. This study found substrate colonization by specific morphological groups mixed across the study; though dominant communities were observed for each substrate present, substrate availability appears to be confounded by a number of variables (climate, stand age and structure and litter layer) not controlled for in this study. Biocrust community morphologies varied across sites, primarily influenced by the surface texture of the substrate and morphology of the individual. Relatively smooth surfaces (rock, bare soil) often resulted in smooth biocrust morphologies, whereas rough surfaces (dead wood, bare soil) tended to result in a rolling morphology. Litter layer directly influenced the relative proportion of substrates colonized, notably affecting dead wood and mineral soil biocrusts. Total biocrust cover increased as precipitation increased as did biocrust preference for dead wood substrates while mineral soil remained unchanged and rock surfaces were negatively represented. Aspect generally followed the anticipated distribution of total biocrust cover with the highest cover on N and NW aspects and lowest on the W aspect. Increases in elevation were negatively related to overall biocrust cover. Soil texture was not found to be directly related to overall biocrust cover, attributed in part to the highly adaptive nature of the biocrust community. Soil organic matter (SOM) influenced total biocrust cover with positive correlations between total cover and increasing SOM content. Soil pH increased as expected across the precipitation range (17 to 159 in/yr) of the transect. Total biocrust cover was found to trend with soil pH, but is believed to be attributed to the parallel relationship between precipitation and pH, rather than pH alone given the relative moderate pH range (4.39 to 6.54) of the study. The distribution and abundance of forest soil biocrusts is strongly influenced by precipitation. The confounding influence of precipitation to litter layer depth and organic matter content (through gradients of vegetative productivity) and soil pH further are concluded to influence substrate preference by morphological groups. Across the variables examined, similarities between the two communities (arid and forest) in response to climate and soil chemistry show parallel relations, justifying the formal establishment of biological soil crust community in forested regions. The differences between communities related to the presence of trees validate the establishment of forest soil biocrusts as distinct community in both form and ecological function with the forests.
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527. [Article] Hydrophobicity of Cindery Typic Cryorthents
The hydrophobicity of soils of the Deschutes National Forest was studied. The soils are Cindery Typic Cryorthents, formed in cinders and ash from Mt. Mazama. Ponderosa pine is the dominant overstory vegetation. ...Citation Citation
- Title:
- Hydrophobicity of Cindery Typic Cryorthents
- Author:
- Evans, Lynn B.
The hydrophobicity of soils of the Deschutes National Forest was studied. The soils are Cindery Typic Cryorthents, formed in cinders and ash from Mt. Mazama. Ponderosa pine is the dominant overstory vegetation. Of particular interest was the effect of prescribed burning on hydrophobicity. Fire has been shown to cause a normally hydrophilic soil to become hydrophobic. This non-wettability reduces water infiltration into the soil. As a result, the potential for erosion increases and less water is available for plant growth. The objectives of the study were to determine (1) whether or not prescribed burning causes the formation of a water repellent layer, (2) which variables affect the hydrophobicity of the soil following burning, (3) the horizontal and vertical extent of the hydrophobic layer, and (4) how long the hydrophobicity persists in the soil. Critical Surface Tension (CST) was measured to characterize hydrophobicity. A site burned 25 June 1982 and a site burned 15 September 1982 were sampled to meet objectives (1), (2), and (3). Objective (4) was met by sampling six additional sites where the time since burning ranged from 9 to 51 months. The presence of pre-burn hydrophobicity, believed to be caused by fungal products, complicated determining the effects of burning on the hydrophobicity of the soil. Pre-burn hydrophobicity was more extensive on the site which was sampled in September than the site sampled in June. Ninety-six % of the sampling points were hydrophobic during September and 42% during June. Two possible reasons were postulated for this difference. First, the amount of hydrophobicity due to the presence of fungal hyphae may vary seasonally; fungal products may accumulate during summer and then leach out of the profile with fall rains and spring snowmelt. Second, avoiding fungal pockets may not have been as successful when September sampling occurred as in June. Soil infected with fungal hyphae was avoided when CST was measured, because the fungal pockets did not form a continuous layer parallel to the surface. Fungal pockets were avoided by observing the light color of the dry fungal soil and the presence of hyphae. The soil had a light color because the water content was low. The soil was drier in September than in June. Distinguishing between fungal and non-fungal soil based on color differences was relatively easy in June, because the non-fungal soil was moist. However, the color difference between fungal and non-fungal soil was not as distinct during September sampling. The difference in color due to water content between fungal and non-fungal soil was small. As a result, the effort to avoid fungal caused water repellent areas was not as successful. More of the sampling points were hydrophobic in September. The June burn caused an increase in the hydrophobicity of the soil. The increase was greatest at the 2-3 cm depth. The hydrophobicity of the soil following burning in the June burn was explained by the degree of litter combustion. Hydrophobicity was produced where complete combustion occurred but not with incomplete combustion of the litter. Pre-burn hydrophobicity of the soil sampled in June occurred more often in the upper 2 cm than at the lower depths. Pre-burn hydrophobicity occurred at 42.5% of the sampling points. Post-burn hydrophobicity occurred randomly at all depths and occurred at 60.5% of the sampling points. On the site burned in September, most sampling points were hydrophobic before burning because of the presence of fungal products. Hydrophobicity decreased in the upper 2 cm of the soil. It was postulated that the hydrophobic fungal products were volatilized by the high temperatures of the prescribed burn and diffused deeper into the soil where they then condensed. The hydrophobicity of the soil following burning in the September burn was correlated with hydrophobicity of the soil be fore burning. Soil was found to be hydrophobic after burning if it was hydrophobic before burning. Measurements of litter depth, water content, and degree of combustion did not explain the variation in post-burn hydrophobicity of the soil at either site. Pre-burn hydrophobicity of the soil sampled in September occurred more near the surface than deeper in the soil. Pre-burn hydrophobicity was found at 96% of the sampling points. Post-burn hydrophobicity was not quite as extensive; 92% of the sampling points were hydrophobic. Post-burn hydrophobicity occurred deeper in the soil than pre-burn hydrophobicity in September, but the difference between depths was not significant. The percentage of hydrophobic sampling points decreased as time since burning increased. The relationship was significant at the 95% confidence level.
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Landslides are a pervasive hazard that can result in substantial damage to properties and loss of life throughout the world. To understand the nature and scope of the hazard, landslide hazard mapping has ...
Citation Citation
- Title:
- Analysis of spatial data from terrain models for landslide predictive mapping
- Author:
- Santha, Rubini
Landslides are a pervasive hazard that can result in substantial damage to properties and loss of life throughout the world. To understand the nature and scope of the hazard, landslide hazard mapping has been an area of intense research by identifying areas most susceptible to landslides in order to mitigate against these potential losses. Advanced GIS and remote sensing techniques are a fundamental component to both generate landslide inventories of previous landslides and identify landslide prone regions. A Digital Elevation Model (DEM) is one of the most critical data sources used in this GIS analysis to describe the topography. A DEM can be obtained from several remote sensing techniques, including satellite data and Light Detection and Ranging (LiDAR). While a DEM is commonly used for landslide hazard analysis, insufficient research has been completed on the influence of DEM source and resolution on the quality of landslide hazard mapping, particularly for high resolution DEMs such as those obtained by LiDAR. In addition to topography, multiple conditioning factors are often employed in landslide susceptibility mapping; however, the descriptive accuracy and contribution of the data representing these factors to the overall analysis is not fully understood or quantified. In many cases, the data available for these factors may be of insufficient quality, particularly at regional scales. These factors are often integrated into a wide assortment of analysis techniques, which can result in inconsistent mapping and hazard analysis. To this end, the principal objectives of this study are to 1) evaluate the influence of DEM source and spatial resolution in landslide predictive mapping, 2) asses the predictive accuracy of landslide susceptibility mapping produced from fewer critical conditioning factors derived solely from LiDAR data, 3) compare six widely used and representative landslide susceptibility mapping techniques to evaluate their consistency, 4) create a seismically-induced landslide hazard map for landside-prone Western Oregon, and 5) develop automated tools to generate landslide susceptibility maps in a regional scale. In this study, semi-qualitative, quantitative and hybrid mapping techniques were used to produce a series of landslide susceptibility maps using 10 m, 30 m and 50 m resolution datasets obtained from ASTER (Advance Space borne Thermal Emission and Reflection Radiometer), NED (National Elevation Dataset) and LiDAR (Light Detection and Ranging). The results were validated against detailed landslide inventory maps highlighting scarps and deposits derived by geologic experts from LiDAR DEMs. The output map produced from the LiDAR 10 m DEM was identified as the optimum spatial resolution and showed higher predictive accuracy for landslide susceptibility mapping. Higher resolution DEMs from LIDAR data was also investigated; however, they were not significantly improved over the 10 m DEM. Next, a series of landslide susceptibility maps were compared from six widely used statistical techniques using slope, slope roughness, elevation, terrain roughness, stream power index and compound topographic index derived from LiDAR DEM. The output maps were validated using both confusion matrix and area of curve methods. Statistically, the six output maps produced, showed accepTable prediction rate for landslide susceptibility. However, visual effects and limitations were noted that vary based on each technique. This study also showed that a single LiDAR DEM was capable of producing a satisfactory susceptibility map without additional data sources that may be difficult to obtain for large areas. In western Oregon, landslides are widespread and account for major direct and indirect losses on a frequent basis. A variety of factors lead to these landslides, which makes them difficult to analyze at a regional scale where detailed information is not available. For this study, a seismically-induced landslide hazard map was created using a multivariate, ordinary least squares approach. Various data sources, including combinations of topography (slope, aspect), lithology, vegetation indices (NDVI), mean annual precipitation, seismic sources (e.g., PGA, PGV, distance to nearest fault), and land use were rigorously evaluated to determine the relative contributions on each parameter on landslide potential in western Oregon. Results of the analysis showed that slope, PGA, PGV and precipitation were the strongest indicators of landslide susceptibility and other factors had minimal influence on the resulting map. An automated tool kit was a byproduct of this analysis which can be used to simply the hazard mapping process and selection of parameters to include in the analysis.
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529. [Article] Effects of a Wind Energy Development on Greater Sage-Grouse Habitat Selection and Population Demographics in Southeastern Wyoming
Western EcoSystems Technology, Inc. and Wyoming Wildlife Consultants, LLC initiated a greater sage-grouse radio-telemetry study at an existing wind energy development in southeastern Wyoming in 2009. The ...Citation Citation
- Title:
- Effects of a Wind Energy Development on Greater Sage-Grouse Habitat Selection and Population Demographics in Southeastern Wyoming
- Author:
- LeBeau, Chad W.
Western EcoSystems Technology, Inc. and Wyoming Wildlife Consultants, LLC initiated a greater sage-grouse radio-telemetry study at an existing wind energy development in southeastern Wyoming in 2009. The University of Wyoming joined this collaborative effort in January 2010, and the National Wind Coordinating Collaborative joined the effort in March 2011. The overall goal of the research was to establish the population-level effects of wind energy development on female sage-grouse seasonal habitat selection and demography. This study represents the only situation in the US where the responses of greater sage-grouse to the infrastructure associated with a wind energy development has been investigated. Our primary objective was to discern the relationship between sage-grouse nest, brood-rearing, and summer habitat selection patterns and survival parameters and the infrastructure of an existing wind energy facility. The Seven Mile Hill (SMH) study area was located north of Interstate 80 and south of the Shirley Basin in Carbon County, Wyoming, US. A control and treatment area was included in the SMH study area, with boundaries of each of these areas determined from lek locations and radio-marked female sage-grouse distributions. The Seven Mile Hill Wind Energy Facility (SWEF; located in the treatment area) consisted of 79 General Electric 1.5-MW wind turbines and approximately 29 km of access roads. The facility became fully operational in December 2008. In addition to the SWEF, other anthropogenic features present in this portion of the study area included approximately eight km of paved roads and 26 km of overhead transmission lines. The control study area had no wind turbines and was adjacent to the SWEF and south of US Highway 30/287. There were approximately 50 km of paved roads and 17 km of overhead transmission lines in this area. The treatment area had four leks that had an average distance of 1.93 km from the nearest SWEF turbines (range = 0.53 to 4.15 km), while the control group consisted of 6 leks with an average distance of 10.99 km from the nearest SWEF turbine (range = 7.09 to 16.16 km). We captured and radio-equipped 346 (160 treatment; 186 control) female sage-grouse within an area consisting of a wind energy development and a control area absent of wind energy development in southeastern Wyoming from 2009–2014. We relocated each radio-marked female approximately twice a week during the nesting, brood rearing, and summer periods. We developed a suite of anthropogenic, vegetation, and environmental covariates to estimate habitat selection and survival for all sage-grouse during the nesting, brood rearing, and summer periods. We used a discrete choice habitat selection model to estimate the relative probability of sage-grouse nest site, brood-rearing, and summer habitat selection within both the control and treatment areas during the post-development period. We did not detect a negative impact of the wind energy facility on nest site selection during the study period. Sage-grouse rearing broods generally avoided suitable brood-rearing habitat near anthropogenic infrastructure that includes wind energy development, major paved roads and transmission lines. Although avoidance was consistent across the years of our study, avoidance of wind turbines was more pronounced in 2012-2014 compared to 2009-2011, suggesting a lag period in the ultimate population-level response to the development of a wind energy facility. Although distance to turbine was not strongly associated with summer habitat selection, the percentage of disturbance associated with wind energy infrastructure did appear to influence summer habitat selection. In addition, we estimated survival during each seasonal period to estimate the effect of the SWEF on population fitness. The SWEF did not have a negative effect on sage-grouse nest survival within the study area over the six-year period, and nest survival did not differ between nests of females captured at treatment and control area leks over the study period. The SWEF did not have a negative effect on sage-grouse brood survival within the study area over the six-year period. Survival was related to habitat features and anthropogenic features that have existed on the landscape for >10 years. Lastly, the SWEF did not have a negative effect on female sage-grouse summer survival within the study area over the six-year period. After controlling for annual and natural variability, we observed a positive effect of the SWEF on female survival when the percentage of disturbance within 0.81 km of a sage-grouse location increased from 0% to 3%. Our study is the first to estimate the impacts of wind energy development on sage-grouse habitat selection and fitness parameters. Female sage-grouse selection of seasonal habitats was variable relative to the infrastructure associated with wind energy facility, but fitness parameters did not appear to be influenced to a great degree by the infrastructure. This pattern of effect is similar to greater prairie-chicken response to a wind energy facility in Kansas but opposite of sage-grouse response to oil and gas development. Ideally, we would have preconstruction data to identify changes in the population and decipher mechanisms in sage-grouse response to infrastructure; however, we are confident that if such impacts to habitat selection and survival did occur then we would have been able to detect these changes over the 6-year study period. The lack of other studies investigating impacts from wind energy development to sage-grouse habitat selection and survival limits our ability to make inferences about the cumulative impacts of wind energy development on sage-grouse, but we were able to describe some of the impacts that wind energy developments may have on sage-grouse populations. Although we attempted to account for possible confounding factors, there is the chance that we did not detect important interactions between environmental features and habitat selection and survival patterns. Future wind energy developments should consider the potential impacts of wind energy development on sage-grouse habitat selection patterns and survival parameters. We recommend facilities similar in size that occupy similar habitats as our study be placed 1.20 km from any occupied sage-grouse nesting, brood-rearing, or summer habitats. We recommend that future research consider predator-prey mechanisms by estimating both avian and mammalian predator densities to better understand the impacts of wind energy development on sage-grouse fitness parameters and to develop appropriate mitigation measures.