This study integrated remotely sensed data, geographic information system (GIS), and classification tree-based modeling to delineate ecological units for the Ashley National Forest. Data points , provided by the Ashley National Forest, with a known location and dominant vegetation type, were related to data layers that were determined to be helpful in a landtype classification. These layers included elevation, slope, aspect, potential solar irradiation, precipitation, geology, basins, Landsat thematic mapper (TM) bands 3, 4, 5, and 6, and basic land cover. These points, with their related information, were then used to train the tree-based model for landtype classification. This resulted in a set of rules, in the form of a binary decision tree, that could be applied to the entire study area. After the landtype classification was obtained, it was cross-classified with geology to produce a landtype association layer. This resulting data layer was compared to an existing landtype association map and it was determined, by cross-tabulation, that the two classifications identified many of the same patterns.

Natural disturbance events influence the patterns and processes in many forest ecosystems. Ecosystem management of coniferous forests in western North America requires the recognition of the importance that natural disturbance regimes have in achieving sustainable resource production and maintaining biological diversity . Mountain pine beetle epidemics have played an historic role in the succession and structure of lodgepole pine forests in this region. Their effects on wildlife habitat and communities are undocumented, but are presumed to be substantial. I sought to quantify these effects in forty 1-ha stands of monotypic, even-aged, mature lodgepole pine forest in northern Utah approximately 3-8 years following an extensive epidemic. I selected 5 stands that were unaffected by the epidemic and 35 that had tree mortalities ranging from 14 to 95 %. Mean understory biomass in 50 1-m2 plots demonstrated an exponential increase from 4g m-2 in unaffected stands, 40 g m-2 in stands with moderate (51-75% dead) tree mortalities, and up to 110 g m-2 in severely (76-100 % dead) affected stands. Plant species diversity and heterogeneity were highest in stands with moderate tree mortality. Horizontal visual obscurity (from 0- 2.5 m high) was highest in stands with> 40% tree mortality. Canopy cover and volume decreased linearly and curvilinearly, respectively, with increasing tree mortality. Foliage height diversity was higher in stands with moderate tree mortality than in stands with high, low, or no mortality. Abundance and diversity of avian species were highest in stands with moderate tree mortality. Small and medium-sized mammal species were more abundant and diverse in stands with moderate and severe tree mortality than in stands with no or low (26-50 % dead) tree mortality, but the pattern is less clear than for avian species. Fecal pellet groups of large ungulates increased linearly with increasing tree mortality, but the pattern of occurrence of snowshoe hare fecal pellets to increasing tree mortality was less clear. Insect abundance and species diversity increased linearly with tree mortality. Canonical correspondence analysis of insect, avian, and mammalian communities revealed that understory vegetation biomass, diversity, and heterogeneity, as well as foliage height diversity, were the habitat factors that consistently explained the distribution of these species in stands affected by beetle-caused tree mortality.

Wildlife managers have fed elk in North America for nearly 100 years. Giving winter feed to elk can compensate for a shortage of natural winter range and may boost elk populations while also helping prevent commingling with livestock and depredation of winter feed intended for livestock. In contrast to these benefits of supplemental feeding, there are economic and environmental costs associated with feeding, and elk herds that winter on feeding grounds have a higher risk of contracting and transmitting disease. Brucellosis is of primary concern now, and Chronic Wasting Disease may be in the future. Many see the discontinuation of winter-feeding programs as a necessary step for decreasing the risk of disease spread due to high animal densities associated with feeding during winter. My research evaluated the use of behavioral training to reduce reliance on supplemental winter feeding of elk, while minimizing population reductions and human-wildlife conflicts. My study was conducted at Deseret Land & Livestock (DLL) in Rich County, UT, where managers at DLL have over 20 years of data on elk feeding during winters of varying intensities. I tested the effectiveness of range improvements, strategic cattle grazing, dispersed supplemental feeding, hunting, and herding to distribute and hold elk in desired areas during winter. I compared elk numbers on the feed ground during this study with historic data on DLL, and also contrasted elk responses with other comparable feed sites in Wyoming that served as controls. In 2 mild winters we completely eliminated elk feeding without incident and were able to reduce the quantity and duration of feeding during 1 severe winter. Since the conclusion of my study, DLL has further reduced quantity and duration of feeding during severe winters, and has completely eliminated feeding in light winters. Based on a Before After Control Impact (BACI) analysis, the reduction in the proportion of the elk population fed at the study site was significantly less than the proportion of the elk populations fed at the control sites in Wyoming (P = 0.057). Based on these results, I anticipate wildlife managers can decrease dependence on costly supplemental winter feeding and reduce the risks of disease while keeping human-wildlife conflicts at a minimum. This research illustrates an adaptive method that can enable wildlife managers to keep elk populations in northern Utah at or near their current size, while constraining disease outbreak and transmission risks within "acceptable" levels.

The highly endemic native fish fauna has experienced dramatic reductions in abundance and range because of anthropogenic activity. In addition to a highly altered flow, temperature, and physical habitat template, many non-native fish species have established populations throughout the basin. The San Rafael River, a tributary of the Green River in southeastern Utah, is home to populations of flannelmouth sucker (Catostomus latipinnis), bluehead sucker (C. discobolus), and roundtail chub (Gila robusta), and has experienced degradations representative of many rivers throughout the Colorado River Basin. Using the San Rafael River as a template, I examined (1) the effect of the non-native fishes on the food web structure of a Colorado River tributary and (2) whether any changes to the food web structure by non-native fishes impact fitness-related vital rates of native fishes in the river. Stable isotope analysis revealed that the non-native fishes present novel predator archetypes to the “three species,” but size-at-age and body condition analyses did not reveal any reduction in fitness between native fishes captured in the presence of the non-native fishes. Additionally, I used site-specific biotic and abiotic measurements to develop a model predicting “three species” relative abundance. Non-native fish abundance and spatially auto-correlated measures of physical habitat were found to be particularly important predictors of “three species” relative abundance. The model was used in combination with a longitudinal habitat survey to predict the current continuous distribution along the length of the lower San Rafael River, as well as to simulate population-level effects of relevant restoration actions. The eradication of non-native fishes resulted in significant population increases for each of the ‘three species,’ and physical habitat restoration resulted in significant population increases when executed in certain reaches, but significant population reductions if executed in other reaches. These results suggest that the restoration of physical habitat without addressing populations of non-native fishes will likely result in a limited response by the “three species,” and that the choice of restoration location is critical to its success.

Large fires (400 ha +) occur about every seven to ten years in the vegetation types located at US Army Garrison Camp Williams (AGCW) practice range located near South Jordan, Utah. In 2010 and 2012, wildfires burned beyond the Camp’s boundaries into the wildland-urban interface. The political and public reaction to these fire escapes was intense. Researchers at Utah State University were asked to organize a system of fuel treatments that could be developed to prevent future escapes. The first step of evaluation was to spatially predict fuel model types derived from a random forests classification approach. Fuel types were mapped according to fire behavior fuel models with an overall validation of 72.3% at 0.5 m resolution. Next, using a combination of empirical and semi-empirical based methods, potential fire behavior was analyzed for the dominant vegetation types at AGCW on a climatological basis. Results suggest the need for removal of woody vegetation within 20 m of firebreaks and a minimum firebreak width of 8 m in grassland fuels. In Utah juniper (Juniperus osteosperma (Torr.) Little), results suggest canopy coverage of 25% or less while in Gambel oak (Quercus gambelii Nutt.) stands along the northern boundary of the installation, a fuelbreak width of 60 m for secondary breaks and 90 m for primary breaks is recommended.

Herbivory is one major force accelerating aspen decline in North America, but it is unclear why herbivores prefer certain aspen stands over others, or over other plant species in the understory. In this dissertation, I determined the influence of nutrients and plant secondary compounds (PSC), physiological state, chemical composition, and prior experience on aspen preference by sheep in controlled pen experiments. In addition, I explored the relationship between herbivory, regeneration, recruitment, and other landscape elements for specific aspen stands within Wolf Creek Ranch in northern Utah using biomass and chemical composition of the understory and chemical defenses of juvenile aspen trees (i.e., the foodscape). Aspen intake was enhanced when lamb diets contained a high crude protein to energy ratio or when the basal diet contained a low density of energy. Intake was depressed as concentrations of PG (phenolic glycosides) increased in aspen leaves or when lambs were fed a high energy to protein ratio. The effects of nutrients on aspen intake were greater when phenolic glycosides in aspen were present at low concentrations. However, when given a choice between aspen leaves of high or low PG content, lamb preference depended more on aspen nutrient and mineral availability, or on prior diet, than on defense chemistry. On the landscape, I found that stands at low elevations with low abundance of nutrients in the understory are more likely to experience less regeneration and recruitment than those growing within nutrient-rich sites. Aspen browsing was negatively correlated with PG content in aspen stands, and elk presence (measured via fecal pellets) was negatively correlated with abundance of understory protein. In conclusion, aspen herbivory appears to be controlled by the interplay between types and amounts of nutrients offered by the landscape and the chemical composition of aspen stands. A clear assessment of these variables on the landscape, i.e., the foodscape, will aid in the development of novel management strategies aimed at providing nutrients (e.g., through supplements, introduced forages) at strategic locations in order to reduce aspen herbivory within at-risk aspen stands.

The causes of conflict among users of outdoor recreation resources have received little attention from recreation researchers. Knowledge of factors responsible for conflict might assist recreation planners' attempts to reduce future instances of conflict and help management focus its conflict resolution efforts. A theory of conflict is offered as the first step in systematically procuring such knowledge. A definition and characteristics of outdoor recreation conflicts are presented; four comprehensive causes of user conflicts are proposed. Ten propositions are used to link these factors to conflict and suggest future research hypotheses. The social psychological dynamics of conflict, as described here, have implications for understanding the sources of user dissatisfaction. In part two, 120 interviews, taken from two conflict situations involving mechanized and nonmechanized forms of recreation, were used to examine the heuristic value of the theory's concepts. A case study format was used for the analysis. The interviews demonstrated a need to distinguish between potential and felt, or experienced, conflict, due to the latter's dependence on a chance social interaction. Nonmechanized users displayed a high conflict potential, indicated by conflict avoidance behavior, which reduced reports of felt conflict. Fewer mechanized users expressed felt conflict. Stereotyping of the opposite group's lifestyle was found in both cases, as was a lack of intergroup communication. A negative evaluation of the other group's lifestyle seems inherent in such stereotypes. Opposing groups sought different outcomes from interacting with a natural environment though backcountry vehicle users showed a more diverse set of interactions than the literature or stereotypes suggest. Users demonstrated possessiveness for a particular recreation place--this orientation may also exist for categories of places such as National Parks. The findings support the contention that differences in lifestyle, modes of experiencing natural environments, and resource specificity are factors responsible for conflict and worthy of future research.

The Oak Ridge Reservation established under The Atomic Energy Commission was the site for uranium enrichment and the construction of the atomic bomb during the early 1950’s and 60’s. Unfortunately, large quantities of “heavy metals” such as mercury, uranium, technetium, plutonium and fission products that were produced were dumped into unlined landfills, settling ponds and surface streams. One such creek affected was East Fork Poplar Creek, whose head water begins at the Y-12 Facilities located on the Oak Ridge Reservation, and was once used as an industrial drainage ditch for runoff, which included mercury and other heavy metals. The release of mercury, in particular, into East Fork Poplar Creek was probably lethal to established seed banks, vegetation, and soil microbial and fungal communities. The soil microbial communities play an important role in ecological processes, and the fungal communities are important, in particular, due to the mutualistic associations shared with more than 85% of plant species. This study evaluating the long term effects of mercury on plant and fungal presence and abundance indicated that soil mercury concentration was not significantly correlated with these factors. In order to better understand the effects of mercury compounds on plant and fungal interaction, a greenhouse study was conducted. Survival of seedlings in mercury-contaminated media was more dependent on mercury compound applied than on the presence of fungal inoculates tested. The ability of four tree species to germinate in different mercury compounds was also investigated. The germination of seedlings in mercury solution was dependent on tree species, mercury compound and concentration. The detection of mercury in environmental samples was based on conventional methods such as cold vapor atomic absorption spectroscopy (CVAAS), and inductively coupled plasma emission mass spectrometer (ICP-MS). Analysis of mercury and other metals by non-destructive techniques such as infrared spectroscopy, specifically near-infrared (NIR) and mid-infrared (MIR) spectroscopy was investigated. Quantitative analysis of plant foliar tissue exposed to mercury was investigated by NIR, and mercury- contaminated soil was investigated by MIR. Due to mercury’s volatility, the ability to differentiate NIR spectra of control versus treated seedlings could not be confirmed through statistical analysis, however MIR spectra obtained from mercury-contaminated soil was used to develop significant calibration models for mercury and several other metals correlated to mercury.

Coal mining is a significant industry in Appalachia. Herbaceous groundcovers are commonly planted to reduce soil erosion and protect water quality during mine reclamation, but many groundcovers may be too competitive to be compatible with trees. The objectives of this research were to investigate the performance of trees planted within different groundcovers and to measure how different groundcovers influence resource availability, specifically soil moisture and light Two studies were performed; one in a greenhouse and the other on 3 mine sites in east Tennessee where seedlings were planted and grown in competition with different groundcovers. Growth, biomass, leaf area, and foliar transpiration of tree seedlings, percent cover of groundcovers, percent volumetric soil moisture, and photosynthetically active radiation (PAR) were measured. In the greenhouse, root-to-shoot ratios of northern red oak seedlings in the presence of competition from switchgrass and in bare treatments were found to be greater than in alfalfa and annual rye treatments. Specific leaf area of seedlings in the annual rye treatment was found to be lower than the other treatments. Seedlings in the bare and switchgrass treatments were found to have greater transpiration rates than in the annual rye and alfalfa treatments. On the mine sites, growth and transpiration of northern red oak, American chestnut, black cherry, and shagbark hickory seedlings did not differ among groundcover treatments. In both studies, percent soil moisture was found to be greatest in the bare and switchgrass treatments, and percent full PAR at 14 cm was found to be greatest in the bare treatment. In the greenhouse, percent full PAR was lowest in the switchgrass treatment and was lowest in the alfalfa treatment in the field. Many factors may explain differences in seedling growth and performance between the greenhouse study and the field study such as tremendous variability in substrates and percent groundcover in the field, micro-site influence, and other unknown factors. Results from this study suggest that of the groundcover species studied, switchgrass may be the most compatible with the hardwoods studied, but more research is warranted to definitively determine the competitive interactions between the tree and groundcover species studied.

In order to fully understand the magnitude of the benefits that forests provide, it is crucial to understand the full suite of ecosystem services that they offer. A southern Appalachian red spruce-Fraser fir forest was intensively analyzed using a variety of methodologies to determine the nature and quantity of some of these services. Many hypotheses exist regarding the future of these spruce-fir forests, which were heavily disturbed by the non-native balsam wooly adelgid during the 1980s. Direct measurements over the course of a decade assessed these hypotheses and indicate that this forest is recovering structure and function. The forest is accruing overstory biomass, with vegetation composition on a trajectory towards historic conditions. By using a total forest inventory of all vegetation from overstory trees to understory mosses, rates of productivity and nutrient cycling were determined. Productivity of this forest at low elevations has returned to pre-adelgid levels, while at high elevations productivity is approaching these levels. In the absence of an intact overstory, forest understory vegetation can compensate by disproportionately cycling and retaining nutrients such as nitrogen that would otherwise leach offsite. The understory of this forest provides an important service in nutrient cycling. Our ability to actively manage forests in order to manipulate levels and rates of carbon sequestration was assessed using stand data and the Forest Vegetation Simulator Growth and Yield Model. Silvicultural intervention proved effective at sequestering additional carbon over a no action alternative by the end of our simulation period. This forest provides a variety of ecosystem services and has retained its ability to recover their function after catastrophic disturbance.