Greenstrips were established at two sites in Utah to determine if seeded, grazed cool-season, perennial grasses would change fire behavior characteristics in areas currently dominated by Bromus tectorum. Frequency data were collected for both grazed and ungrazed seeded species and resident weed species. Moderate spring grazing did not negatively impact the establishment of seeded species at Camp Williams. Grazing at Promontory Point decreased Agropyron desertorum frequency and increased the frequency of Pascopyrum smithii. Biomass data collected for grazed and ungrazed treatments in both years indicated that moderate spring or winter grazing the first two years of establishment did not negatively impact seeded species. Modeled fire behavior in grazed plots indicated that fires occurring under most fire weather conditions could be managed with hand crews at Camp Williams. Simulated fire behavior at both sites indicated that management (i.e., grazing) was necessary to realize the desired fire behavior from the established greenstrips.

Interest in the restoration of landscapes native to the Intermountain West is growing as the value of these arid ecosystems is increasingly recognized. Many landscapes within the Intermountain region have been impacted by grazing, development, recreation, and other human-caused disturbances. The complex relationships within the native plant communities of these arid landscapes need to be well-understood biologically, while considering their aesthetic contribution, if restoration efforts are to succeed. Although the use of ecologically appropriate native species is increasing in popularity, there is discontinuity between aesthetics and meaningful ecological contributions. A series of studies was designed to aid in the restoration of a site located at the Utah Botanical Center in Kaysville, Utah. The restoration site is situated along the I- 15 corridor which interfaces urban development. The high visibility and educational purpose of the site requires that aesthetic as well as ecological concerns are addressed in the restoration of the native plant community. Specifically, the establishment of Intermountain grassland species was assessed using a variety of methods to test establishment rates as well as the potential value to the system of biologically fixed nitrogen provided by native legumes early within the establishment period.

Two field experiments determined an effective intertrap distance (ITD) for early detection and delimitation sparse gypsy moth (Lepidoptera: Lymantriidae, Lymantria dispar L.) populations in mountainous terrain. This study found that current Animal and Plant Health Inspection Service trapping guidelines are not sufficient for early detection of small gypsy moth populations in mountainous terrain. Detection trapping in mountainous terrain should have an ITD of not more than 804 m. Delimiting trapping should use a grid design with an ITD of 152 m. A related study determined natural adult male mortality in the climate of the intermountain West, which includes Utah, Nevada, western Wyoming, and southern Idaho. An interaction was found between mortality, temperature, and humidity. During high temperatures, most mortality occurred on the second day. When lower temperatures prevailed, the largest percent mortality occurred on the third or fourth day.

Hydroclimatic variability in the western United States (the West) is characterized by a north-south dipole pattern of precipitation and streamflow variance, with centers of opposite association in the Pacific Northwest and the Desert Southwest. These dipole centers tend to react in opposite fashion to tropical Pacific Ocean conditions, and the resulting contrast in precipitation variability is an important component of Western climate. Teleconnection impacts are not as well understood in the transition zone separating the centers of opposite association, located primarily within the semi-arid Intermountain West. This leads to low hydroclimatic predictive capacity in the transition zone region, an area that is extremely important for water supply in the West. In this dissertation, I examine paleohydroclimatic variability in this region using dendrochronology, investigate recent variability through a synoptic climatology approach, and assess future conditions based on climate change projections.Overall, this dissertation's findings confirm that the transition zone region is highly vulnerable to extremes in hydroclimatic variability and underscore the need for improved predictive capacity in the region. In the Snake River headwaters, low- to mid-elevation Pseudotsuga menziesii trees are the strongest recorders of winter precipitation, a vital component of water supply, and the season of precipitation impacting growth is a major component of the overall variability between tree-ring sites in the region. The 415-year reconstruction of Snake River streamflow indicates that extended droughts, more severe than those recorded in the instrumental period, have occurred in the pre-instrumental past. Streamflow in the upper Snake River is strongly linked to Pacific Ocean conditions and sensitive to storm track position. The West's precipitation dipole has a surprisingly narrow transition zone that has shifted in its location over time in some areas but has remained remarkably stationary across Nevada and Utah. Projected climate changes - including warmer temperatures, changing seasonality, reduced snowpack, and changes in the storm track position - highlight the importance of understanding climate-water linkages for future water resource management.

During 1993- 1994, I investigated wildlife depredation at Intermountain West fish hatcheries to quantify losses, determined the reliability of bioenergetics models and hatchery manager perceptions to predict losses, and investigated the effectiveness of simple control measures. I observed predators and surveyed managers to quantify the extent of depredation losses and to identify the species responsible. Great blue herons (Ardea herodias), black-crowned night herons (Nycticorax nycticorax), ospreys (Pandion haliaetus), and California gulls (Larus californicus) were the most significant predators of hatchery fish in the field study, and were perceived as such by hatchery managers. Losses to avian predators at two hatcheries were 7.0% and 0.6% of annual production based on my observational data, but hatchery managers believed depredation losses were 15% at each hatchery. I estimated the consumption of rainbow trout (Oncorhynchus mykiss) by great blue herons using bioenergetics models of existence metabolism, existence metabolism plus reproductive costs, and field metabolic rate. compared the model-based predictions to observed consumption rates of free-ranging herons foraging at a fish hatchery. The fish consumption predicted by the existence metabolism model and observed consumption were similar from October- June. During the breeding season, observed consumption was higher than consumption predicted by the existence metabolism model but lower than that expected from the energy requirements for breeding individuals. This result was expected given that only a portion of the bird population was breeding. Although consumption predicted by the field metabolic rate differed significantly from observed consumption for more months than the existence metabolism models, predicted annual consumption from field metabolic rate and observed annual consumption were not signliJcantly different (.E < 0.05). Peak observed consumption occurred during August and September and was predicted by the model. Performance of the three models may be improved with estimates of population structure and more reliable population estimates. I evaluated the effectiveness of perimeter fencing in reducing heron depredation on fish raised in concrete raceways at a trout hatchery in Midway, Utah. Fences were constructed of single-strand monofilament line placed 20 cm above raceway walls. Fences had no impact on the number of birds foraging or their fish consumption rate.

Low-water landscaping is an essential tool for water conservation in the arid Intermountain West (IMW) for managing limited supplies and population-driven increased demand. The IMW harbors a large number of drought-tolerant native species that have potential for use in the low-water use landscape (LWL). However, many species are not available in the nursery trade due to their morphological confusion and establishment difficulty in the managed landscapes. The overall goal of this study is to elucidate morphological, ecophysiological, and genetic distinctions within two IMW native plant genera containing species with high urban low-water landscape potential.

Pastures in the Intermountain Western United States mainly consist of cool-season grasses which lack production without supplemental nitrogen. Legumes provide nitrogen at reduced cost compared to nitrogen fertilizer. There is a need for proven methods of inter-seeding legumes into existing cool-season grass pastures as well as knowledge of how animals prefer legumes to grasses and how the nutritive value of forages change throughout the growing season. This research provides a resource for effective integration of legumes into pastures of the Intermountain West. Alfalfa, birdsfoot trefoil, and cicer milkvetch were inter-seeded into existing cool-season grass pastures following pretreatments of light tillage, mowing and glyphosate. Early spring and fall inter-seeding was unsuccessful, while late spring was moderately successful with overall alfalfa frequency of 30% after a year. Summer inter-seeding was the most successful with birdsfoot trefoil, alfalfa, and cicer milkvetch frequency of 42, 32, and 22%, respectively. In the animal preference study, when compared to tall fescue, birdsfoot trefoil was always utilized more.In most observations birdsfoot trefoil utilization was higher than orchard grass. While in all comparisons with meadow bromegrass there was no difference in utilization. During early growth, perennial ryegrass utilization was higher than birdsfoot trefoil utilization, but no difference in utilization was detected in later observations. Overall, birdsfoot trefoil was utilized 73% overall while grass utilization was 74, 67, 64, and 53% for perennial ryegrass, meadow bromegrass, orchardgrass and tall fescue, respectively. The interaction of growth stage and time of season on the nutritive value of alfalfa, birdsfoot trefoil, cicer milkvetch, orchardgrass, perennial ryegrass and tall fescue was determined. In the spring to early summer, legume nutritive value decreased rapidly with maturity, in midsummer the nutritive value decreased slowly with maturity, while in late summer the nutritive value remained stable. In the spring, grass nutritive value decreased rapidly, while in mid to late summer all grass regrowth was vegetative and the nutritive value remained stable. By inter-seeding in the summer, effectively managing mixed pastures, and utilizing forage at its highest nutritive value, legumes can benefit the pastures of the Intermountain West.

Advances in drilling technology and increasing resource prices contributed to a boom in oil and natural gas production in the Western U.S. in the first decade of the 2000s. Following the boom, a strain of state-level legislation emerged calling for the transfer of federal lands to the states. A justification for the proposed transfers is the claim that state management will responsibly increase oil and gas production levels currently held back by federal regulations and management. However, a substantial literature indicates that dependence on mineral wealth can be a problematic economic development strategy resulting in slower growth and other undesirable socioeconomic outcomes. Using geological variation in oil and gas abundance in the Intermountain West, this study examined the effects of resource abundance on county wage levels and growth rates over the period 1990 to 2010. Areas of oil and gas abundance were further classified by federal, state, and private surface land ownership to examine institutional ownership effects on wage levels and growth rates. Overall oil and gas abundance was shown to have a positive impact on wage levels and growth rates, while institutional ownerships were found to have significantly differing effects on county wages. State ownership was usually associated with higher wage levels and growth rates than federal ownership, likely due to a lengthy permitting process for drilling on federal lands. Private ownership had insignificant effects on local wages, likely due to absentee ownership. The results provide no evidence of a ‘curse of natural resources’ in the region and lend a modicum of support to state land transfer bills.

Due to end users irrigating with excess water, water conservation of turfgrass can make a large impact in urban water conservation by reducing water applied while still maintaining visual appearance. This study was conducted to determine if Kentucky bluegrass (Poapratensis L.) can be deficit irrigated to maintain minimum acceptable appearance while conserving water. The study investigated water stress in terms of stomatal conductance, chlorophyll index, leaf temperature and predawn leaf water potential at the point of water stress, or where visual quality no longer meets expectations during dry down conditions. Water use was measured over well established Kentucky bluegrass with an eddy covariance system that was validated with soil water measurements. Turfgrass was irrigated at 80% of reference evapotranspiration based on allowable depletion of 12 mm of soil water during growing season that was considered to be well-watered. Two dry downs were conducted over a two-year period (early and late summer). Turfgrass was allowed to dry down without irrigation until visual quality reached the minimum acceptable points (score ≤ 6). During drying periods, visual rating, chlorophyll index, predawn leaf water potential, and leaf temperature with stomatal conductance rapidly decreased once stomatal conductance fell to approximately half of well-watered levels. Both soil water content and evapotranspiration had weak correlation with stomatal conductance; however, stomatal conductance tended to have higher correlation with the change in soil moisture than with the change in crop evapotranspiration. Soil water use and eddy covariance data in terms of crop evapotranspiration had high correlation. The plant water use factor ranged from around 0.8 to 1.1 under well-watered condition corresponding to visual rating from 7 to 9. At the minimum acceptable point of visual rating, which is 5.5 to 6, the plant factor ranged from 0.65 to 0.87. This value of plant factor is quite high at this point. Even when Kentucky bluegrass went below acceptable visual quality, the grass still used significant amounts of water with the plant factor value ranging from 0.6 to 0.8. The data suggested that deficit irrigation cannot be applied with Kentucky bluegrass in the Intermountain West area.

Corn (Zea mays L.) hectarage has increased rapidly in Utah and Idaho in recent years due to expansion of the dairy industry, but little is known about corn production practices that optimize yield and quality of silage corn in semi-arid irrigated cropping systems. The objective of this study was to determine the dry matter yield and quality effects of corn hybrids grown in different plant densities and row widths in the Intermountain West. Field experiments were conducted under irrigation in 2015 and 2016 at locations near North Logan, Utah and Jerome, Idaho. The experimental design was a randomized complete block in a split-split plot arrangement with four replications. The whole plot treatment was hybrid (DKC 49-29, DKC 56-54, and DKC 61-88), the sub-plot treatment was row width (76 and 51-cm), and the sub-sub plot treatment was plant density (61,776 to 123,552 plants ha-1 at intervals of 12,355 plants ha-1). The 51-cm row width resulted in forage dry matter yield increases of 4-7% over corn in 76-cm rows. Hybrids differed in response to row width, with no difference detected for the 99-RM hybrid but a significant yield increase for the 106- and 111-RM hybrids by planting in narrow rows. Yield increased quadratically as plant population increased from 61,776 to 123,552 plants ha-1 for all hybrids. The only forage nutritive value that was influenced by row spacing was crude protein (CP), where the 76-cm row spacing showed a 4.5% advantage over the 51-cm row width. Starch increased approximately 3% from the lowest to highest plant densities tested. Net returns showed possible positive increases when comparing row width adjustments. Silage corn yield and quality in the Intermountain West appears to be optimized in 51-cm rows at a plant population between 86,487 and 98,842 plants ha-1.