During the past quarter of a century there has been considerable investigation into the effects of fluorides on living organisms. It has been well established, as a result of these studies, that both small and elevated amounts of fluorides present in the environment may have a marked toxic effect upon gaining entry into the organism. Much of the research involving fluorides and the living organism has been confined to experimentation with animals, although considerable evidence indicates that plants are also subject to injury if fluorides are present in the atmosphere or the soil. The great majority of the research dealing with effects of fluorides on animals has been confined to higher vertebrates, principally domestic farm species. The concentration of fluoride research in this area has been prompted by economic pressures arising from natural, industrial, or accidental fluoridation of livestock. For the most part, these investigations have been confined to determination of toxicity levels to various domestic species, while the mode of fluoride action upon living organisms has often been neglected. Some investigators, however, have postulated "defense mechanisms" within the organism whereby active fluoride ion is removed from systemic circulation and is either deposited in less active tissues of the body, or, is excreted in some manner. Such mechanisms would offer a degree of temporary protection of the organism from harmful effects of the fluoride ion.

This study examined historic change of riparian plant communities and fluvial geomorphic response of gravel-bedded streams and their floodplains to over 50 years of hydrologic disturbance. Four tributary basins of the Arkansas River were analyzed. Lake Creek, Clear Creek, and Cottonwood Creek are drainages similar in area, physiography, and vegetation composition. However, Lake Creek may receive an instantaneous discharge of approximately 28 m3sec-1 from the Twin Lakes tunnel, over three times the normal flow of the stream during spring runoff. By contrast, Clear Creek and Cottonwood Creek, nonaugmented streams, were used as controls to compare the historic and present condition of natural flowing streams with Lake Creek. Lake Fork was also examined, another augmented stream that carries transmountain water stored in a reservoir to the Upper Arkansas River. Hydrologic data collected from U.S.G.S. gaging stations were used in an attempt to identify relations between specific flow events and corresponding changes in fluvial landforms, riparian vegetation patterns, and channel morphology. Topographic cross sections of the channel and floodplain were surveyed and hydraulic geometry at each field site was examined. Aerial photographs from 1938-39, 1956-57 , and 1988 were incorporated into a Geographic Information System (GIS) to prepare a series of land cover maps of the river corridor at eight field sites on augmented and nonaugmented streams. Results indicate channel morphology and riparian vegetation cover on the active floodplains of Lake Creek and Lake Fork have experienced substantial change from natural physical and biologic conditions as a result of historic and present flow augmentation practices. The increase in water discharge without a natural sediment load in Lake Creek and Lake Fork appears to have caused accelerated rates of channel bank erosion, incision, and bank retreat below transbasin diversion releases. In some downstream reaches characterized by gentler slopes and wider valley bottoms, the width-depth ratio of the channel has increased and sinuosity has decreased. Sites carrying transmountain water were characterized by higher shear stress and specific stream power values and larger bed material compared to control sites. Consequently, the Lake Creek and Lake Fork drainages show temporal and spatial loss of riparian vegetation adjacent to the stream channel in response to historic and present flow augmentation practices. Control watersheds, Clear Creek and Cottonwood Creek, where natural flow regimes exist, did not experience similar magnitudes of change in channel morphology or spatial distribution of riparian vegetation.

The objectives of this study were (a) to apply sediment and associated plot data from various infiltrometer studies to the parameters in the Universal Soil Loss Equation, a modified version of the original Musgrave Equation, and a modified version of the original Universal Soil Loss Equation, and compare the computed results with the measured soil loss, (b) to suggest reasons for any differences between computed and measured soil loss, and (c) to suggest improvements for each equation so that it will give results near the measured soil loss. The data used consisted of 2805 infiltrometer plots collected by previous researchers in a variety of rangeland conditions, both in the western United States and Australia, and included the necessary information needed to compute the factors in each of the above equations. Simple and multiple linear regression techniques were used to make the evaluations by computing the coefficient of determination (R2), correlation coefficients (r), and to optimize each factor in the equations by placing an exponent on it. The results showed that the three soil loss prediction equations are not universal, but, for the most part, explain sediment yield with varying degrees of accuracy in different situations with no apparent trends or patterns. However, most individual mine sites and other sites with loosely consolidated soil resembling fallow conditions showed high R2 values when the computed sediment yield was regressed against measured sediment yield. Little improvement was made in reducing the variability of the equations by placing exponents on each factor indicating that the factors, as determined in each equation, do not explain sediment yield under western rangeland conditions. In summary, the prediction equations are not recommended as "universal" predictors of sheet erosion in western rangelands, but, may be applied in specific situations.

Due to loss of habitat, Gunnison sage-grouse (Centrocercus minimus) currently occupy 8.5% of their presumed historical range. One population survives in Utah, occurring in San Juan County. The Gunnison Sage-grouse Rangewide Conservation Plan and the San Juan County Gunnison Sage-grouse Conservation Plan recommended management strategies to address identified conservation threats to the Utah population. I addressed three conservation strategies identified in the plans: 1) creation and enhancement of brood-rearing areas; 2) assessment of habitat conditions within the Gunnison Sage-grouse Conservation Area; and 3) prevention or reduction of perching events by avian predators on distribution line power poles. From 2007-2009, I addressed the conservation strategy of creating mesic brood-rearing areas in Conservation Reserve Program fields and native sagebrush areas by evaluating the role of irrigation and dormant season cattle grazing on habitat. Vegetation and arthropod diversity in irrigated versus non-irrigated plots did not differ (p>0.01). Conservation Reserve Program plots exhibited greater arthropod abundance and cover of perennial grass than the native sagebrush plots, but lower diversity of perennial grasses and abundance and diversity of forbs (p<0.01). The second conservation strategy I addressed was the completion of an assessment of habitat conditions within the Gunnison Sage-grouse Conservation Area. I measured vegetation conditions within habitat occupied and unoccupied by Gunnison sage-grouse. Cover and height of grasses exceeded guidelines for occupied and unoccupied habitats. Forb cover was below recommended guidelines in occupied habitat. Sagebrush cover was below guidelines for winter habitat. Habitat restoration efforts should focus on retaining existing sagebrush cover and establishment of sagebrush, forb, and grass cover within Conservation Reserve Program fields. The third conservation strategy I evaluated was the retrofitting of distribution line power poles with perch deterrents to discourage avian predators from perching. I evaluated the efficacy of five perch deterrents. The perch deterrents did not mitigate potential avian predators from perching. A deterrent designed for insulators, in combination with physical deterrents we tested, has potential to prevent perching. These studies provided a sound first step that can be built upon by the Monticello/Dove Creek Local Working Group to improve habitat conditions, reduce the threat of avian predation, and plan future conservation activities within the Conservation Area.

While range-wide population declines have prompted extensive research on greater sage-grouse (Centrocercus urophasianus), basic information about southern periphery populations, such as the Bald Hills population in southern Utah, has not been documented. The objective of this research was to determine habitat preferences and space use patterns of the Bald Hills sage-grouse population which occurs in an area of high potential for renewable energy development. I tracked 66 birds via VHF telemetry in 2011 and 2012 and surveyed vegetation plots throughout the study area. I found that the population was primarily one-stage migratory with seasonal distributions that did not correspond well with previously developed suitable habitat maps (based on local biologist knowledge and lek data) for all seasons; I also found that mean home range sizes ranged from 82 km2 to 157 km2. Nesting hens did not select for any measured vegetation characteristics within the study area, while brood-rearing hens selected for high forb cover. Birds at summer sites (non-reproductive bird locations during the summer season) selected for greater grass and forb cover and lower shrub cover compared with random sites. Overall, Bald Hills sage-grouse used areas with greater shrub canopy cover and lower grass and forb cover than recommended in habitat guidelines. Ten predictor variables were used to model suitable seasonal habitat using Maximum Entropy (maxent). All models were created for the Bald Hills population and projected to the Bureau of Land Management Cedar City Field Office management area and produced excellent model fit (AUC > 0.900). The Bald Hills population had similar nesting and winter habitat preferences as other populations but different brood-rearing and summer habitat preferences. I found local management techniques to be an important driver of seasonal habitat selection; birds selected for areas that had undergone habitat treatments (such as broadcast burn and crushing) within the previous 10 years. My results indicated the Bald Hills periphery population occupies marginal habitat and has adapted unique seasonal habitat preferences. Managers of isolated, fringe, and low-density populations should develop locally specific management guidelines to address the unique adaptations and ensure the persistence of these populations.

The demand for recreation on public lands has been growing steadily, resulting in undesirable impacts on certain resources as well as recreation experiences. The problem addressed by this research is the uneven distribution of recreational use that causes a concentration of impacts. This thesis describes the development and testing of a method to reduce the uneven/concentrated recreation use occurring on the public lands. The basic objectives of the study were to determine the effectiveness of redistributing recreationists by the use of photographs and a decisional process using photographic information and to identify its potential as a tool in meeting management objectives. The experimental treatment device was the Visual Decision Making Process consisting of color photographs, a map and a selection matrix used in the decision-tree to match people to places that would best suit their needs. Recreationists were surveyed on three different weekends during the spring season of 1980 in the San Rafael Swell of southeastern Utah. People who had been contacted during that time were randomly assigned to treatment or no-treatment control groups. A home interview was conducted prior to the 1981 spring recreation season. After the season, both the treatment and no-treatment control groups were contacted for posttest questioning. Data were collected from the contact questioning, observation, and posttest questionnaires. The results indicated that recreation use was influenced by the Visual Decision Making Process, but only a small percentage of people who went through the process went to an area they chose. While the major influence of the process was not significantly proven, there seemed to be a trend in change behavior. This small percentage of change may be an adequate amount to meet management objectives of lessening impacts. It was also found that persons driving four-wheel drive vehicles and larger groups were significantly more influenced to redistribute than car/pickup drivers and smaller groups. Recommendations are made for management practices to reduce uneven/ concentrated recreation use and suggestions for further research are offered.

The relationship between rainfall and runoff was examined for twelve selected Arizona watersheds. Expedient runoff volume model coefficients and runoff curve number model parameters were examined using standardized structure, with modifications to adjust the model for small initial abstractions and large watershed storage capacity. Forest-land management practices were examined for their effects on curve number coefficients. The effects of rainfall characteristics were also evaluated with respect to changes they induce in curve number populations. Evaluations included a runoff fraction, a simple multiplier of storm volume to produce runoff volume. The accuracy of this model is promising for more permeable watersheds.

Biochar has been shown to act as an effective sorbent for many organic and inorganic contaminants (including phosphate) and can help to improve the quality of our fresh water resources by preventing eutrophication. Most of the high efficiency biochar phosphate-adsorbent feedstocks are modified with chemical pretreatment, phytoremediation or anaerobic digestion to accumulate desired elements. The main objectives of this project were to first engineer magnesium (Mg) and calcium (Ca) altered biochar by chemical pretreatment followed by pyrolysis at either 350 or 550°C and evaluate their phosphate adsorption rate and potential as compared to their unaltered counterparts. Determination of surface physiochemical characteristics of the unaltered (U350 and U550), Mg-altered (Mg350 and Mg550), and Ca-altered (Ca350 and Ca550) hardwood biochars was also completed. The unaltered biochars did not adsorb any phosphate which was likely due to a lack of Mg or Ca and crystalline structures as confirmed by ICP-AES and XRD. Adsorption kinetics revealed that both the Ca-altered and Mg-altered biochars took about 10 days to reach equilibrium. The Langmuir isotherm model was the best fitting model for all altered biochars and Mg550 adsorbed the most phosphate with a Langmuir maximum capacity (Q) of 135.8 mg/g at pH 9. XRD spectra confirmed crystallinity for both the Ca-altered and Mg-altered biochars for calcite (CaCO3) on the Ca-altered biochar and both periclase (MgO) and brucite (Mg(OH)2)on the Mg-altered biochars. SEM images of Mg550 followed by EDS confirmed the presence of nano-sized flakes on the biochar surface and identified them as the primary phosphate adsorption sites. SEM images of Ca550 identified globular, rather than flakey structures on the biochar surface and EDS offered further confirmation that these were calcite minerals. Although Ca350 and Ca550 adsorbed phosphate from solution, Mg350 and Mg550 exhibited a much greater phosphate sorption potential with Q at 18.91, 16.34, 39.59 and 135.8 mg/g (pH 9), respectively. This may be attributed to the morphological differences between the highly crystalline flake-like structures of the Mg altered biochars and the globular structures on the surface of the Ca altered biochars. The mechanisms revealed for phosphate sorption include electrostatic interactions, precipitation, and ligand exchange.

Historically, coyotes were associated with the western United States. During their expansion eastward, coyotes have become more tolerant of humans and have been able to live in varying degrees of urbanization. One main question ecologists around the country are asking is how coyotes are surviving in anthropogenic environments. To aid in answering this question, I have compared coyote land use preference generally and specifically during coyote breeding season, winter and summer, human tourist seasons, and day and night. I also compared coyote land cover preference for deciduous and evergreen cover types during natural seasons. I found that, in general, there was a high variation of preference between and within land use categories. More broadly however, they prefer natural areas over non-natural areas. They used natural and non-natural land use types equally in winter and summer, and during tourist and off-tourist seasons with increased variation in preference during seasons with higher human activity. They had a higher preference for non-natural land use types at night. There is no difference in coyote preference for deciduous or evergreen cover types during the seasons.

Following catastrophic exploitation throughout the North Atlantic, breeding seabird populations have begun to recover thanks to regulatory protection and restoration and management efforts. As bird populations increase, new challenges emerge, including overgrowth of vegetation that limits the open nesting habitat favored by most tern species. Though managers have used a variety of measures to reduce vegetation cover, these techniques have rarely been quantified or compared experimentally. During the summers of 2009 and 2010, I applied two different techniques, controlled burning and artificial weed barriers (muslin fabric and artificial turf) to experimental plots on Eastern Egg Rock and Outer Green Island, near-shore seabird nesting islands in mid-coastal Maine. I then monitored vegetation regrowth and use by nesting terns to assess the effectiveness of these techniques for opening and maintaining Common Tern nesting habitat during a full breeding season, comparing treated plots to vegetated control plots and existing tern nesting habitat. Burned areas did not remain open for the full nesting season, but regrew shortly after laying, leading to near-complete nest failure in these plots. Tern nest and fledging success was similar in weed barrier (1.37 chicks/pair) and untreated tern nesting habitat (1.38 chicks/pair) plots. Replacement of existing vegetation, tested at a limited scale on Outer Green Island, did not succeed. These three techniques represent only a small fraction of vegetation management techniques used throughout the North Atlantic region. Through literature review and consultation with North Atlantic colony managers, I collected information on vegetation management on 34 tern nesting islands between 33 and 55° N latitude and developed a summary of different vegetation control techniques used. I identified 14 technique types suitable for use in nesting colonies: i.e., that can be applied before and after (but not during) the nesting period of May-July, that do not cause destructive impacts to the surrounding ecosystem, and that involve materials and labor that can be transported to inaccessible offshore islands. Of these techniques, 8 created usable tern nesting habitat for a full breeding season, and the most successful techniques required constructing habitat over existing vegetation. The success of different methods depended heavily on the plant communities and soil types involved. In general, vegetation management options were more limited and less successful for elevated, rocky islands than for low, sandy islands. Often, techniques that successfully removed one species or group of species (i.e., perennial grasses) failed due to rapid colonization by other species (i.e., herbaceous annuals). This review of past and ongoing vegetation management techniques used on seabird nesting islands, including their costs, methods for application, and effectiveness, provides seabird managers a reference when evaluating current and future vegetation management programs.