In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing habitat, thereby threatening their long-term local and regional viability. Though lichens have a rich history as air pollution indicators, I believe that they may also be useful as a metric of community diversity associated with habitat change. To date, few studies have specifically examined the status of aspen's epiphytic lichen community in the Rocky Mountains. A preliminary study was conducted using 10 transect-based plots to assess lichen species substrate preferences between aspen and various conifer species and to gain basic knowledge of species diversity. Following this work, I established 47 plots in the Bear River Range of northern Utah and southern Idaho to evaluate the effects of forest succession on epiphytic macrolichen communities. Plots were located in a narrow elevational belt (2,134-2,438 m) to minimize the known covariant effects of elevation and moisture on lichen communities. Results show increasing lichen diversity and a decrease in aspen-dependent species as aspen forests succeed to conifer cover types. The interactive roles of stand aspect, basal area and cover of dominant trees, stand age, aspen bark scars, and recent tree damage were examined in relation to these trends. An aspen index score was developed based on lichens showing an affinity for aspen habitat. I present a landscape-level multivariate analysis of short and long-term factors influencing epiphytic lichen communities in aspen forests. Nonrnetric multidimensional scaling (NMS) ordination stressed the importance of succession and local air pollution sources in shaping lichen communities. I also investigated the role of historic human intrusions and climate on aspen forests and aspen dependent epiphytic lichens at the landscape-level. Implications of this work include 1) realization of nitrogen impacts on ecosystems, 2) the potential for using lichens as bioindicators for monitoring aspen stand health, and 3) suggestions for working with natural disturbance regimes to minimize human impacts on aspen and associated species.

Providing adequate outdoor recreational opportunities to the public is now a national problem. Of the many influences affecting the demand for recreation, increased income, population increase, sociological changes, and rapidly increasing technological developments are the more important. In the face of these factors, we must plan better to insure sufficient future needs. This will require evaluation and development of many recreation opportunities. The Bear Lake are of northeastern Utah and southeastern Idaho is situated along U.S. 89 and within close driving distance of much of Utah's population. Up to the present there has been little orderly or planned development of Bear Lake. Nevertheless use of the area has been increasing, particularly for water-oriented sports. Many parties traveling through the area are on their way to the Northern parks, i.e., Yellowstone, Grand Teton, and Glacier, or from these parks to Salt Lake City and points south or west. Thus, if the Bear Lake area were developed to provide services to the tourist, economic benefit to the area may be increased. To date, lakeside development by farmers has resulted in a "shanty" appearance, with old barns, sheds, and various log structures. No zoning regulations have been initiated for the lake shore areas. A local service group, the Bear Lake Improvement Association, is considering various ideas to improve the existing facilities as well as ideas for developing new facilities. The group's primary purpose at the present is to improve the lake's appearance by clean-up efforts and to advertise the area through the use of pamphlets and signs. This attempt may acquaint more people with the recreational opportunities and facilities offered in Bear Lake Valley. Currently, the economy of the Bear Lake area is primarily agricultural. However, the limited amount of tillable soil and the short growing season greatly restrict the agricultural potential of the area. Additional income-producing endeavors of a recreational nature could be explored. The Bear Lake area has many undeveloped attractions which could be developed to draw tourists. Because of these opportunities, research has been undertaken to examine the possibility of expanded recreational development by private operation in the Bear Lake area.

A study of the spring and summer habitat preferences of blue grouse was conducted on the Bear River Range in northern Utah. The main objective was to determine the important factors associated with habitat selection by blue grouse during the breeding season. One hundred and two sampling areas, delimited by similarities in vegetation and topography, were thoroughly searched with a dog for blue grouse. Fifty-four bio logical and physical variables were measured for each sampling area. Chi-square tests performed on all variables showed 11 of the 54 variables to be significant at an alpha of 0.20. These 11 variables (li sted below) were considered to be the important factors influencing habitat selection by blue grouse. (1) search area type (2) area exposure (3) elevation (4) percent forested (5) understory density (6) primary cover species (7) secondary cover species (8) percent cover maples (Acer grandidentatum) (9) percent cover mixed brush (10) percent cover sagebrush (Artemisia tridentata) (11) total acres The chi-square test only determined if a variable significantly effected habitat selection by blue grouse. To determine whether this effect was positive or negative, the percent occurrence of areas on which blue grouse were present, or absent, was determined. Results indicated that the most favorable blue grouse habitat was draws at 5,500 -6.499 feet elevation. This favorable habitat contained 1-10 percent cover by maples, or a higher percent of maple which provided a large amount of edge effect; the presence of mixed brush or sagebrush, a medium understory, and an area incline of 5-19 percent.

The study of environmental history suggests that nature and culture change all the time, but that the rate and scale of such change can vary enormously. During the late 19th and early 20th centuries, Anglo settlement in the American West transformed landscapes and ecologies, creating new and complex environmental problems. This transformation was particularly impressive in Cache Valley, Utah's Bear River Range. From 1860 to 1910, Mormon settlers overused or misused the Bear River Range's lumber, grazing forage, wild game, and water resources and introduced invasive plant and animal species throughout the area. By the turn of the 20th century, broad overuse of natural resources caused rivers originating in the Bear River Range to decline. To address the water shortage, a small group of conservation-minded intellectuals and businessmen in Cache Valley persuaded local stockmen and farmers to support the creation of the Logan Forest Reserve in 1903. From 1903 to1910, forest managers and forest users attempted to restore the utility of the landscape (i.e., bring back forage and improve watershed conditions) however, they quickly discovered that the landscape had changed too much; nature would not cooperate with their human-imposed restoration timelines and desires for greater profit margins. Keeping in mind the impressive rate and scale of environmental decline, this thesis tells the heretofore untold environmental history of the Bear River Range from 1860 to 1910. It engages this history from an ecological and social perspective by (1) exploring how Mormon settlers altered the landscape ecology of the Bear River Range and (2) discussing the reasons why forest managers and forest users failed to quickly restore profitability to the mountain landscape from 1903-1910. As its value, a study of the Bear River Range offers an intimate case study of environmental decline and attempted restoration in the western United States, and is a reminder of how sensitive our mountain ranges really are.

The majority of interior cutthroat trout (Oncorhynchus clarki) subspecies have been extirpated from large rivers by anthropogenic activities that have fragmented habitats and introduced non-native competitors. Selective pressures against migratory behaviors and mainstream river occupation and conservation schemes that isolate genetically pure populations above barriers have restricted gene flow and prevented the expression of fluvial life history traits in many populations. Existing knowledge about the movements and home range requirements of fluvial cutthroat trout is therefore limited. We implanted a total of 55 Bonneville cutthroat trout (BCT) in the Thomas Fork River, Idaho, with radio transmitters and located them weekly or bimonthly from October to April of both 1999/2000 and 2000/2001. Half of these fish were located above a seasonal diversion barrier and half were located below. We found fish to be more mobile than previously reported. Individuals located above the diversion barrier in 2000/2001 occupied significantly larger home ranges (median 3,675 m, range 2,500-8,900 m) and moved more frequently (mean 0.89 movements/contact, range 0.57-1.0) than other fish. Fish occupied habitats in the lower Thomas Fork and Bear River during the winter that were marginal or uninhabitable during other seasons. During the spring of both years we located fish in both upstream and neighboring tributaries up to 84 km away from our study site. Our results document the existence of a fluvial component of BCT in the Bear River and its tributaries and suggest that successful efforts at conservation of these fish will focus on mainstream habitats and the maintenance of seasonal migration corridors.

The project was initiated in June of 1958 and financed by the National Science Foundation and the Wildlife Management Department of Utah State University. The broad aspects of the study were to determine if a relationship exists between certain physical and biological factors and benthic fish densities. The project vas divided into two parts: (l) to determine the time and extent of thermal stratification, zooplankton densities, conductivity changes within the lake and conductivity differences between the lake and its tributaries; (2) to determine it a relationship exist between benthic fish densities, temperatures, depths, conductivities and benthic zooplankton densities. The data were analyzed statistically and a separate regression analysis was run on each factor to determine the degree of relationship between that factor and benthic fish densities.

The primary goals of this research were to investigate 3 ecological factors influencing black bear (Ursus americanus) foraging behavior on an Alaskan salmon (Oncorhynchus spp.) stream: fish availability, social dynamics, and human activity. Over 900 observation hours were Jogged at 2 falls from July !-September I 1993-1995; the lower falls were open to public for wildlife viewing, but the upper falls were restricted to research personnel. In general, black bears responded to differences in fish accessibility on both spatial and temporal scales. All years of the study, 3 indices of bear activity (bear minutes, bear numbers, bout duration) and fish capture rates were significantly higher (all Ps <0 I 0) at the upper falls where fishing opportunities were more abundant. Furthermore, seasonal variation in black bear density was indicative of fluctuations in fish accessibility: bear numbers were highest midseason when fish appeared more abundant, but decreased towards the end of the summer. Although many bears fished within 3 to 5 m of one another, the majority of intraspecific interactions (65-75%) were benign as opposed to agonistic with a preponderance of "passive deferrals" where bears detoured around rather than confronted conspecifics. Only 5. 7% of all interactions resulted in reversals or circularity, providing some evidence for a linear dominance hierarchy. The most dominant bears fished where salmon were highly accessible for longer periods of time, therefore capturing more fish than subordinates each year. Of interspecific interactions, black bears were more likely to be displaced when encountering brown bears on the same side rather than opposite sides of the creek. Of 24 recognized bears, 71% were observed from 75-100% of the time at the upper falls; only 8% (2 females) fished solely at the lower falls. Five of 8 bears that fished exclusively at the upper falls (all large males) appeared wary of researchers upon their arrival. Based on quantile regression analyses, we found that visitor numbers acted as a ceiling on fishing duration of black bears at the lower falls in 1994 and 1995. Furthermore, 2 habituated bears seen frequently at the lower falls spent less time in view (maximum values) as visitor group size increased.

Conflicts between humans and black bears (Ursus americanus) jeopardize the safety of both humans and bears, especially when bears become food-conditioned to anthropogenic food sources in areas such as campgrounds. Interest in using non-lethal techniques, such as aversive conditioning, to manage such conflicts is growing. I conducted a captive experiment at The Wildlife Science Center in Minnesota and two field experiments in the La Sal Mountains, Utah, to investigate the effects of taste aversion conditioning using thiabendazole (TBZ) with a novel flavor cue and food removal on black bear food consumption and visitation to human food sources. In 2007, I conducted food trials with 6 captive black bears (3 control, 3 treatment). Controls received 1 kg baked goods scented with a peppermint-canola oil mixture and treatments received 1 kg baked goods also scented with a peppermint-canola oil mixture but mixed with 10-20 g TBZ. In the 2007 field experiment, I baited 24 field sites with 300 g of baked goods during a baseline phase for approximately 3 weeks. Half of these sites were then treated with 10 g of TBZ and camphor during a treatment phase for 4 weeks. In 2008, I baited 22 sites with 300 g of baked goods during a baseline phase for approximately 4 weeks. I then removed food and discontinued baiting at half of the sites for 4 weeks. Infrared cameras and barbed-wire hair snags were established at field sites to document bear visitation. I did not establish taste aversion in treated bears in captivity and bears fully consumed food in the majority of trials. Treating food supplies with 10 g TBZ and camphor flavor did not significantly reduce bear visitation (P = 0.615) or food consumption at field sites (P = 0.58). However, I observed a significant reduction in bear activity at sites where food was removed (P = 0.006). Potential reasons for my failure to reduce bear visitation using thiabendazole include insufficient conditioning, reluctance of bears to desist in investigating sites that previously contained untreated food, and masking of a treatment effect due to continued encounters of sites by new individuals.

Bear Lake is located in southeastern Idaho and north-central Utah. The lake has a maximum altitude of 5923 feet and an area of approximately 110 square miles. Surrounding the lake are carbonates, shales, and sandstones of lower Paleozoic through middle Mesozoic ages. The many streams and springs that originate in these rocks are probably the main contributors to the chemistry of the lake. Water from Bear River, which flows into the north end of the lake, also contributes to its chemistry. Quartz, aragonite, dolomite, calcite and clay minerals are the main minerals in the lake-bottom sediments. Quartz is generally the dominant mineral in shallow, shoreline areas, whereas aragonite is generally the dominant mineral in deep water. Dolomite occurs in patches near the shoreline along the west and south sides, whereas calcite is fairly evenly distributed throughout the lake. Grains of quartz are detrital in origin. Grains of dolomite and calcite are detrital in origin. Mud-sized aragonite is a primary precipitate that forms pseudoolites around detrital sand grains and lumps of mud-sized particles. The solubility products of aragonite, calcite, and dolomite all are exceeded in the lake water, which, therefore, is supersaturated with respect to all three. Aragonite is more soluble than calcite in water, but chemical and mineral analyses show that mud-sized aragonite is precipitating directly from solutions in Bear Lake, whereas calcite apparently is not. Other workers have attributed the preferential precipitation of aragonite to the inhibition of calcite nucleation in the presence of a high Mg++/Ca++ ratio, a condition present in Bear Lake. Mud-sized calcite and dolomite may be forming syngenetically in the lake sediments as a result of inversion of aragonite to calcite and subsequent replacement of calcite to dolomite, or may be entirely detrital in origin.

In the summer of 1932, an investigation of some biological, physical, and chemical conditions at the Bear River Migratory Waterfowl Refuge, Utah, was begun at the Utah State Agricultural College to determine some of the factors governing the biological productivity of brackish-water marshes. Unfortunately, lack of funds made it impossible to continue work beyond the first season.