Historically, kit foxes (Vulpes macrotis) once occupied the desert and semi-arid regions of southwestern North America, ranging from Idaho to central Mexico. Their range-wide decline has warranted the kit fox to be listed as endangered in Colorado, threatened in California and Oregon, and designated as a state sensitive species in Idaho and Utah. Once considered the most abundant carnivore in western Utah, the kit fox has been in steep decline over the past decade, creating a demand to determine kit fox presence. Currently there is little consensus on which survey methodology is best to detect kit fox presence. We tested 4 survey methods (scat deposition, scent station, spotlight, trapping) along 15 5-km transects within a minimum known population of radio collar kit fox. Home range sizes for kit foxes on the study site were extremely large, averaging 20.5 km2. Scat deposition surveys had both the highest detection probabilities (= 0.88) and were the most closely related to known fox abundance (r2 =0.50, P = 0.001). For detecting kit foxes in a low density population we suggest using scat deposition transects during the breeding season. This method had low costs, was resilient to weather, had low labor requirements, and entailed no risk to the study animals.Next in determining kit fox presence is estimating kit fox distribution. We developed resource selection functions (RSF) using presence data from the noninvasive scat surveys to model kit fox distribution. We evaluated the predictive performance of RSFs built using three popular techniques (Maxent, fixed-effects and mixed-effects general linear models) combined with common environmental parameters (slope, aspect, elevation, soil type). Both the Maxent and fixed-effects models performed to an acceptable level with relatively high area under the curve (AUC) scores of 0.83 and 0.75, respectively. The mixed-effects model over valued higher elevations and had poor model fit. This study demonstrated that it was possible to create valid and informative predictive maps of a species distribution using a noninvasive survey method for detecting a carnivore existing at low density. By demonstrating the application of noninvasive surveying to model habitat quality for a small mesocarnivore, wildlife management agencies will be able to develop predictive maps for species of interest and provide more knowledge to help guide future management decisions.

Restoration of Great Basin sagebrush communities is often attempted without understanding the potential impacts of either restoration treatments on the seed pool or the seed pool on restoration efforts. In addition, few studies have examined seed pools of the Great Basin and the role of vegetation in structuring seed pool communities. I evaluated soil seed pool dynamics of a Great Basin sagebrush community in a restoration context. In Chapter 1, I determined the relationship between the compositions of the seed pool and aboveground vegetation and the effect of shrubs (microhabitat effects) and perennial bunchgrass cover (community phase effects) on the seed pool community composition, seed density, and seed pool species richness. To evaluate the relationship between the two communities and the effects of microhabitat and community phase, the aboveground vegetation and the soil seed pools of different community phases and microhabitats were sampled prior to restoration. Similarity and distance metrics and non-metric multidimensional scaling (NMDS) were used to asses the relationship between the two communities. NMDS and analysis of variance (ANOVA) were used to determine the effects of aboveground community phase and microhabitat on the seed pool community. Results suggest that the relationship between the aboveground vegetation and seed pool community compositions varied according to the organizational level used for vegetation. In addition, microhabitat and community phase did influence seed density but not species richness. I sought to evaluate the effects of restoration treatments on the seed pool community in Chapter 3. To assess the impacts of restoration treatments, the seed pool community before and after treatments was censused. NMDS of the seed pool community and ANOVA on dominant species of the seed pool were performed to determine treatment effects. Results from this research suggest seed pool community composition and seed density varied temporally and spatially. Tebuthiuron and Plateau may have altered community composition whereas prescribed burn affected seed density. This research is applicable for land managers by helping determine the most effective restoration treatment, which will include effects on the seed pool.

Environmental factors at Neponset and Woodruff Narrows reservoirs were evaluated to determine their effects on molting Canada geese. More geese utilized Woodruff Narrows. Geese apparently favored the larger expanse of open water and adequate food supply. Most of the molting geese were from the Bear River drainage. Some geese came from scattered areas in Utah, Idaho, Wyoming, and Montana. After molting, the geese flew to migration staging areas in southeastern Idaho before migrating to wintering areas in southern California and Arizona. Females outnumbered males by 6 percent. The mean annual mortality rate for adult geese was 42 percent. Recovery rates between the sexes were not significantly different (P≤0.01). Juvenile geese were 1.4 times more vulnerable than adults to hunting mortality. Hunting pressure on the geese at the reservoirs was not great enough to be detrimental to the flock. Of 89 nests, 53 percent were successful . Mean clutch size was 4.85 eggs per nest with a range of 1-7. Mammalian and avian predators destroyed 25 percent of the eggs. Forty-seven broods were observed with an average brood size of 4.77 young. Other water fowl populations did not affect the goose population.

Over the last two decades, mountain pine beetle (Dendroctonus ponderosae) populations reached epidemic levels across much of western North America, including high elevations where cool temperatures previously limited beetle persistence. Many high-elevation pine species are susceptible hosts and experienced high levels of mortality in recent outbreaks, but co-occurring Great Basin bristlecone pine (Pinus longaeva), the longest-living non-clonal organism, were not attacked. I assessed Great Basin bristlecone pine resistance to mountain pine beetle by evaluating mountain pine beetle host selection behavior and reproductive success in this species. To evaluate mountain pine beetle host selection preference for Great Basin bristlecone pine, I used no-choice 48-hour attack box experiments that confined pioneering female beetles onto pairs of living Great Basin bristlecone and limber pine (P. flexilis), a susceptible host tree species. To investigate the effect of induced tree defenses on host selection behavior, I repeated the tests on paired sections of Great Basin bristlecone and limber pines that had been recently cut, thereby removing their capacity for induced defensive reactions to an attack. Mountain pine beetles avoided Great Basin bristlecone pine relative to limber pine, suggesting that Great Basin bristlecone pine has a high level of resistance to mountain pine beetle due at least in part to stimuli that repel pioneering females from initiating attacks, even when induced defenses are compromised. To investigate mountain pine beetle reproductive success in Great Basin bristlecone pine, I compared the mating success, fecundity, and brood production of mountain pine beetle parents placed in cut Great Basin bristlecone pine bolts with that of mountain pine beetles placed in cut bolts of limber pine and lodgepole pine (P. contorta), two susceptible species. Initial reproductive development was similar in all three tree species, but nearly all brood in Great Basin bristlecone pine died before emerging. The extensive offspring mortality observed in Great Basin bristlecone pine may be a key evolutionary driver behind mountain pine beetle aversion to the species. These findings suggest that Great Basin bristlecone pine is a highly resistant species with low vulnerability to climate-driven increases in mountain pine beetle outbreaks at high elevations.

Great Basin bristlecone pine (GBBP) (Pinus longaevaBailey) is one of the longest-lived organisms on Earth, and is one of the most highly fragmented high elevation conifer species. Throughout the Great Basin of the Intermountain West, GBBP are being impacted by changing disturbance regimes, invasive species, and climate change. To better understand the effects of climate variability and ecological disturbances in GBBP systems, three studies were designed and implemented. The first characterized the distribution of forest fuel in stands of GBBP and predicted how fuels may change under future climate scenarios. Using the Forest Inventory Analysis (FIA) plot variables of tree species, height, diameter at breast height (DBH), canopy base height (CBH), coarse (CWD) and fine (FWD) woody debris across elevational gradients, this study examined the effects of changes to fuel loading on predicted changes in fire behavior and severity. All classes of FWD decreased with elevation, and only 1000-hr fuels remained constant across elevational transects. This, combined with lower CBH and foliar moisture and increasing temperatures due to climate change, suggested increased fire potential at the GBBP treeline. The second study examined the role of volatile organic compounds (VOCs) and tree chemistry and their response to the environment. VOCs and within needle chemistry were collected and analyzed along elevational gradients near the northern and southern limits of GBBP. Random Forest analysis distinguished elevation using VOCs, with 83% accuracy, and identified the compounds most important for classification. Ordination revealed that temperature, heat load index, and relative humidity were each significantly correlated with VOCs. Within-needle chemistry provided less predictive value in classifying elevation (68% accuracy) and was correlated only with heat load index. These findings suggest that GBBP VOCs are highly sensitive to the environment. The final study explored the role of VOCs in host selection of mountain pine beetle (MPB). Mountain pine beetles oriented toward VOCs from host limber pine (Pinus flexilis James) and away from VOCs of non-host GBBP using a Y-tube olfactometer. When presented with VOCs of both trees, females overwhelmingly chose limber pine over GBBP. While there were only a few notable differences in VOCs collected from co-occurring GBBP and limber pine, 3-carene and D-limonene were produced in greater amounts by limber pine. There was no evidence that 3-carene is important for beetles when selecting trees, however, addition of D-limonene to GBBP VOCs disrupted the ability of beetles to distinguish between tree species. Climate change will impact how forests are managed and this research could provide insight into the mechanisms underlying the incredible longevity of this iconic tree species.

No description available.

Impacts of humans on ecosystems in western United States have necessitated ecological restoration, which includes the development of native seed that can be used for revegetation efforts. Development of such seed sources are costly and time consuming. This study describes the use of non-parametric multiplicative regression analysis (NPMR) to develop a predictive model for occurrence of sulfur-flower buckwheat (Eriogonum umbellatum Torrey) population seed collection. This perennial forb species is of interest for seed source development in the western United States. Presence and absence data for E. umbellatum was taken from the Utah Division of Wildlife Resources Big Game Range Trend project as well as herbarium specimens across Utah, U.S.A. NPMR, a statistical niche modeling system that selects the best predictor variables and develops probability of occurrence estimates multiplicatively, was used to select predictor variables from spatially explicit data made available in a Geographic Information System (GIS). Two models were created using NPMR, one with a suggested default minimum average neighborhood size and the other with a less-restricted minimum average neighborhood size. GIS maps of models were created, artificially classified into low, medium, and high probability areas, and validated in the field in Tooele County, Utah. Of 68 possible physiographic, climatic, and soil variables provided for analysis, NPMR selected 4 variables for the default minimum average neighborhood model and 10 variables for the less restricted neighborhood model. The default model had a higher descriptive statistic (log β value) and mapped a larger area than the less restrictive neighborhood model. When increased minimum neighborhood sizes were selected during the development of the probability maps, the resulting areas of probability prediction decreased. The presence rates of E. umbellatum in field-validated test sites were 7.4%, 12.0%, and 28.6% for the low, medium, and high probability sites, respectively. Although presence rates of field validated data were lower than the predicted probability ranges for those same sites, presence rates increased with increased probability ranges. Using the generated model can reduce the cost and time necessary to locate plants compared to searching for species populations using an undirected approach.

Whether active or passive, dispersal accompanied by gene flow shapes the population genetics and evolutionary divergence of species. Indirect methods which use genetic markers have the ability to assess effective dispersal—that which resulted in gene flow. My objective was to see if an aquatic insect and an obligate aquatic invertebrate show similar phylogeographic patterns and genetic uniqueness. Hyalella azteca and Callibaetis americanus were collected from 4-5 springs in each of six basins in the Great Basin of western North America. No dispersal or genetic studies of C. americanus have been conducted to date. However, several studies focusing on mtDNA diversity of H. azteca have revealed a tremendous degree of cryptic diversity in the desert springs of the Great Basin. Nested clade phylogeographical analysis (NCPA), FST values, AMOVA, and Mantel tests were used to examine geographical associations. I also used traditional phylogenetic approaches including maximum parsimony (MP) and likelihood (ML) analyses using cytochrome c oxidase subunit I (COI), 28S, and 16S as genetic markers. The mitochondrial COI sequence divergences in C. americanus were higher than H. azteca COI divergences within springs but lower among springs. FST values were very high in H. azteca reaching near fixation for certain alleles. C. americanus FST values were lower suggesting greater gene flow and, consequently, greater dispersal rates. Even though Mantel tests did not detect significant isolation by distance when evaluating all haplotypes together, nested clade analysis was able to examine smaller networks of related haplotypes and detect significant isolation by distance. Whereas the genetic structure in C. americanus was dominated by restricted gene flow with isolation by distance, H. azteca was characterized more by gradual range expansion followed by fragmentation. Mayflies likely showed more gene flow than amphipods because of their flight capabilities, but movement was still restricted by long distances between isolated springs.

Following excavations in the Promontory Caves and at several open sites in the Provo River Delta region, Steward (1937) characterized the Promontory culture as large game hunters. He based this on the high number of bison bones recovered within the Caves. Excavations at additional Promontory sites along the Wasatch Front contain faunal assemblages which differ significantly from those in the caves, showing that people living at open sites relied more heavily on small game, waterfowl, and aquatic resources than large game. These differences have been mostly attributed to Steward's sampling strategy and lack of screening, but faunal material recovered during 2011 excavations at the caves support Steward's initial assessment: the people living in the caves were hunting large game and little else. Using faunal data from seven sites, I discuss how the faunal assemblages differ and the implications of hunting practices in discussions of Promontory culture.

Observations of Bromus tectorum L. (cheatgrass or downy brome) monocultures have shown that populations are susceptible to stand die-off or replacement failures. Die-offs, where the seed bank from the previous year fails to emerge, occurs in cheatgrass stands and it is unclear the trigger or cause. The fungus Fusarium has been identified in plant and seed samples from die-offs and may drive die-off activity through pathogenicity. Die-off recovery may take several years but cheatgrass populations eventually reestablish. The purpose of our study was to determine whether Fusarium is a potential player in a die-off, and understand how die-offs recover after multiple years of stand failure. Our objectives were to determine: 1- litter and water effects on die-off activity; 2- if fungal pathogens, such as Fusarium, decrease the proportion of cheatgrass emergence in a die-off; and 3- whether direct or broadcast seeding, water, and litter treatments increase establishment in recovering die-offs. Litter absent plots had significantly (P < 0.0001 and P < 0.001) more emergence at 49.2% and 41% compared to litter present plots 21.3% and 23.7%. The litter absent plots significantly (P = 0.0003 and P = 0.001) increased survival (82% and 52%) compared to litter present plots (70% and 41%). Direct planted versus broadcast seeding had significantly (P < 0.0001) more emergence, 36% to 11.9%. The addition of Fusarium inoculum to field plots did not effectively replicate anticipated disease levels. The fungicide treatment did not have a significant influence at either site. The results from the study indicate that nothing inhibits cheatgrass from establishing following a persistent die-off disturbance. A unique window may be available for land managers to revegetate natives in invasive populations as large quantities of cheatgrass seeds fail to emerge during die-off events.