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Full-Text Articles in Ecology and Evolutionary Biology

Ultraviolet-B Radiation: Effects On Pollen Of 34 Taxa, And Inheritance Patterns And Carryover Of Radiation Response In Arabidopsis, Javad Torabinejad May 1999

Ultraviolet-B Radiation: Effects On Pollen Of 34 Taxa, And Inheritance Patterns And Carryover Of Radiation Response In Arabidopsis, Javad Torabinejad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although considerable research has addressed effects of elevated ultraviolet-B (UV-8) radiation on vegetative plant structures and processes, the reproductive biology and patterns of inheritance of UV-B tolerance have received much less attention. I examined the effects of UV-B radiation on pollen of 34 taxa. I also addressed questions concerning the patterns of inheritance of UV-B tolerance in Arabidopsis thaliana and examined potential cumulative carryover effects of UV-B exposure through multiple generations of this species.

In the first study, a significant reduction in pollen germination occurred in only five species, but pollen tube growth in more than half of the species …


Efficacy Of Guard Llamas (Lama Glama) In Reducing Canid Predation On Domestic Sheep, Laurie E. Meadows May 1999

Efficacy Of Guard Llamas (Lama Glama) In Reducing Canid Predation On Domestic Sheep, Laurie E. Meadows

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Predation, especially by canid predators, is a significant cause of sheep loss for many producers. In recent years, the use of llamas to protect sheep from predators has gained recognition as a depredation control method. I conducted a field experiment to test the effectiveness of llamas in reducing canid predation on domestic sheep. Twenty-one llamas were placed with Utah sheep producers. Data collected from these flocks over 20 months were compared to similar data collected from flocks without llamas. Comparisons between treatment and control flocks included (1) proportion of flocks with losses to predators, (2) mean predation rates on ewes …


The Reproductive Biology And Edaphic Characteristics Of A Rare, Gynodioecious Saxifage: Saxifraga Bryophora Var. Tobiasiae (Saxifragaceae), Kimberly Pierson May 1999

The Reproductive Biology And Edaphic Characteristics Of A Rare, Gynodioecious Saxifage: Saxifraga Bryophora Var. Tobiasiae (Saxifragaceae), Kimberly Pierson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I examined the reproductive biology and general ecology of Saxifraga bryophora var. tobiasiae, a rare saxifrage endemic to the West Salmon River Mountains of central Idaho. Saxifraga bryophora var. tobiasiae combines asexual reproduction via bulbils with a sexual mixed-mating system. Flower production occurred in 1996 only, whereas bulbil production occurred in 1995, 1996, and 1997. Bulbil production precedes floral bud formation and is the dominant form of reproduction. When flowering occurs, outcrossing is promoted by protandry and the gynodioecious mating system found in all populations. No autogamous or agamospermous seed set was observed in either female or hermaphrodite flowers, …


Utilization Of Spatially Distributed Soil Resources By Several Species Common To The Great Basin, Sarah Duke May 1998

Utilization Of Spatially Distributed Soil Resources By Several Species Common To The Great Basin, Sarah Duke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heterogeneous spatial and temporal distributions of soil resources important to plant growth have been documented in the sagebrush steppe ecosystem. There can exist as much variability in soil resources within the root zone of individual plants as exists across an entire field. The objective of this dissertation research was to evaluate how plants respond to, utilize and influence the spatial heterogeneity of soil resources. The three specific sets of questions addressed are outlined in the three main chapters of this dissertation.

My first study addressed how the number and concentration of phosphorus (P) patches in the root zone of an …


Perceived Fairness And Effectiveness Of Rangeland Collaborative Processes, Kimberly J. Richardson May 1998

Perceived Fairness And Effectiveness Of Rangeland Collaborative Processes, Kimberly J. Richardson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Involvement in collaborative partnerships in natural resource management has become a popular method for natural resource management agencies to collect public input, cope with conflicts, and develop ecosystem management plans. This thesis evaluates various collaborative processes, emphasizing multiple-owner partnerships. Qualitative interviews of 46 landowners in Utah were conducted to reveal concerns and suggestions regarding multiple-owner landscape-level collaborative partnerships. Landowners were concerned about private property rights infringement and losing control of their private land. Landowners were primarily concerned about the fairness and effectiveness of any partnership in which they were involved.

However, they were willing to consider participating if certain procedural …


Limitations On Canada Goose Production At Fish Springs National Wildlife Refuge, Utah, Dorie S. Stolley May 1998

Limitations On Canada Goose Production At Fish Springs National Wildlife Refuge, Utah, Dorie S. Stolley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Canada geese (Branta canadensis) recently have become management problems in some areas due to overpopulation. At Fish Springs National Wildlife Refuge (NWR), managers are concerned with the opposite situation. Despite attempts to boost production, only 18 to 34 goslings of the western Canada goose (B. c. moffitti) were produced per year, from 1989 to 1993. I studied the breeding population from March to July in 1996 and 1997. Results suggest that production is limited in 3 ways: low gosling survival, low nesting success for ground nests, and low number of breeding pairs.

Gosling survival to fledging …


Merits Of Using Tranquilizer Trap Devices On Leg-Hold Traps Used To Capture Gray Wolves (Canis Lupus), Duane P. Sahr May 1997

Merits Of Using Tranquilizer Trap Devices On Leg-Hold Traps Used To Capture Gray Wolves (Canis Lupus), Duane P. Sahr

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gray wolves (Canis lupus) are frequently captured with leg-hold traps for reintroduction, relocation to reduce depredations on livestock, or as subjects for research projects. Wolves captured with leg-hold traps often sustain injuries to their feet, legs, and teeth during struggles to escape. Other studies have shown that the use of tranquilizer devices on leg-hold traps reduces such injuries to coyotes. This study (1) assessed whether use of tranquilizer trap devices (TTDs) on leg-hold traps reduced the severity of injuries sustained by captured wolves, and (2) examined the effects TTDs have on nontarget species caught during wolf capture operations. Data were …


Evaluation Of Physical And Behavioral Traits Of Llamas (Lama Glama) Associated With Aggressiveness Toward Sheep-Threatening Canids, Sandra M. C. Cavalcanti May 1997

Evaluation Of Physical And Behavioral Traits Of Llamas (Lama Glama) Associated With Aggressiveness Toward Sheep-Threatening Canids, Sandra M. C. Cavalcanti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Canid predation poses a serious threat to the sheep industry in the United States. Llamas are becoming popular among livestock producers as part of their predation management programs but there is little information on the factors associated with llama guarding behavior. This study examined several physical and behavioral attributes of individual llamas to assess whether they might predict the aggressiveness llamas display coward canids. The study was conducted in three phases. The first involved determining some physical and behavioral traits of individual llamas. Twenty individuals were randomly assigned to one of four groups (n = 5/group) and frequencies with which …


Identification Of Belowground Woody Structures Using Molecular Biomarkers, Benny R. Bobowski May 1997

Identification Of Belowground Woody Structures Using Molecular Biomarkers, Benny R. Bobowski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Within the last two decades substantial progress has been made in understanding seed bank dynamics and the contribution of the soil seed bank to a post-disturbance plant community. There has been relatively little progress, however, in understanding perennial bud bank dynamics and the contribution of the soil bud bank to secondary succession. This lack of information is due primarily to the inability to reliably identify roots, rhizomes, and lignotubers that lie dormant beneath the soil surface. This scientific investigation, therefore, addressed the issue of identification of belowground woody structures.

The first objective was to develop a methodology that utilizes molecular …


Wetland Delineation Of Camp Ripley In Minnesota, Richard A. Spencer May 1997

Wetland Delineation Of Camp Ripley In Minnesota, Richard A. Spencer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Department of Defense (DoD) maintains approximately 25 million acres of land that is used for military training in the continental United States. Currently, federal and state laws and regulations require that the DoD land be managed so that any activity, including training, will have a minimal effect on the natural environment.


The Effects Of Temperature Regime And Food Availability On Growth Rates Of Young-Of-The-Year Colorado Squawfish (Ptychocheilus Lucius) In The Green River, Utah, Craig J. Schaugaard May 1997

The Effects Of Temperature Regime And Food Availability On Growth Rates Of Young-Of-The-Year Colorado Squawfish (Ptychocheilus Lucius) In The Green River, Utah, Craig J. Schaugaard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of different daily temperature regimes and food availability on growth rates of Colorado squawfish (Ptychocheilus lucius) were determined using field and laboratory experiments. Daily temperature and food gradients were observed in river backwaters (important nursery habitat for juvenile Colorado squawfish). High fluctuating temperatures (± 5-8° C) were observed daily in the shallow, terminal ends of backwaters. Where backwaters were in contact with the river (mouth), daily temperature fluctuations decreased (± 2° C). Food availability also varied spatially between the mouth and end of each backwater. To test whether Colorado squawfish growth rates varied in different areas …


Ecological Amplitude And Invasion Of Diffuse Knapweed At Yakima Training Center, Washington, Donna Denise Wilcox May 1996

Ecological Amplitude And Invasion Of Diffuse Knapweed At Yakima Training Center, Washington, Donna Denise Wilcox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Diffuse knapweed (Centaurea diffusa) is an introduced annual or short-lived perennial from Eurasia that has become a threat to native rangelands in the Pacific Northwest. Military training activities on the Yakima Training Center (YTC) increase the likelihood that knapweed will expand its range at YTC. This study, conducted in a major watershed at YTC, focused on: 1) how a variety of environmental variables influences knapweed distribution, 2) the use of Landsat Thematic Mapper (TM) imagery to map existing knapweed populations, and 3) the use of a logistic regression model and geographical information systems (GIS) to create a potential …


Second Growth Forest As Potential Marten Habitat In Western Newfoundland: An Examination Of Forest Habitat Structure And Microtine Abundance, Brian R. Sturtevant May 1996

Second Growth Forest As Potential Marten Habitat In Western Newfoundland: An Examination Of Forest Habitat Structure And Microtine Abundance, Brian R. Sturtevant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The American marten (Martes americana) is associated with large tracts of relatively undisturbed, mature coniferous forests. I examined coarse woody debris (CWD) structure and small mammal abundance with respect to forest age and stem structure within second-growth forests, in comparison with old-growth stands in western Newfoundland. Results suggest that a critical change in marten habitat quality may occur at stand senescence, due to decreased tree competition, more complex subcanopy structure, and increased meadow vole (Microtus pennsylvanicus) abundance.

Analysis of stem structure within a chronosequence of 19 second-growth stands indicated high intertree competition, with dense canopy closure …


A Survey Of Employees Of The United States Department Of Agriculture's Animal Damage Control Program, Susan A. Schroeder May 1996

A Survey Of Employees Of The United States Department Of Agriculture's Animal Damage Control Program, Susan A. Schroeder

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the attitudes of employees of the United States Department of Agriculture's Animal Damage Control (ADC) Program. This research examined ADC employees' attitudes about wildlife, the ADC program and ADC employment, wildlife damage management methods, euthanasia and the killing process, and the role of various public and private groups on ADC policy. This study also applied the theory of organizational capture to the ADC program to test its utility in explaining the attitudes and behaviors of employees. Results were based on a survey of ADC employees conducted in January 1995.

Survey responses were analyzed to explore associations between …


Mule Deer Highway Mortality In Northeastern Utah: An Analysis Of Population-Level Impacts And A New Mitigative System, Mark E. Lehnert May 1996

Mule Deer Highway Mortality In Northeastern Utah: An Analysis Of Population-Level Impacts And A New Mitigative System, Mark E. Lehnert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rerouting highways to accommodate construction of the Jordanelle Reservoir in northeastern Utah caused a dramatic increase in vehicle collisions with mule deer (Odocoileus hemionus). I evaluated the effectiveness of a new system of highway crosswalk structures installed to reduce deer losses and preserve seasonal migrations. In addition, I constructed computer simulation models to investigate how highway mortality has impacted the Jordanelle deer population.

The crosswalk system restricted deer crossings to specific, well-marked areas along highways where motorists could anticipate them. Subsequent to installation, mortality declined 42.3% and 36.8% along a four-lane and two-lane highway, respectively. I was unable …


An Ecological History Of Tintic Valley, Juab County, Utah, Jeffrey A. Creque May 1996

An Ecological History Of Tintic Valley, Juab County, Utah, Jeffrey A. Creque

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work was a case study of historical ecological change in Tintic Valley, Juab County, Utah, an area historically impacted by mining and ranching activities common to much of the American West. The temporal framework for the study was approximately 120 years, the period of direct Euroamerican influence. In recognition of the ecological implications of cultural change, however, the impacts of prehistoric and protohistoric human activity on study area landscape patterns and processes were also explicitly addressed.

The study included a narrative description of historic land uses and ecological change in Tintic Valley, and examined the changes in landscape patterns …


Livestock As Seed Disseminators For Reseeding Degraded Rangelands: The Role Of Dung In Gap Formation And Plant Establishment, Brian S. Auman May 1996

Livestock As Seed Disseminators For Reseeding Degraded Rangelands: The Role Of Dung In Gap Formation And Plant Establishment, Brian S. Auman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Livestock (cattle and sheep) were examined as seed disseminators for reseeding degraded Intermountain rangelands. "Hycrest" crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult. X A. cristatum (L.) Gaert.] seed was fed to yearling Holstein steers and Suffolk ewes. Dung was collected from each animal type and deposited on plots of high and low densities of an annual [cheatgrass (Bromus tectorum L.)] and perennial [squirreltail (Sitanion hystrix Nutt.)] grass species. The experiment evaluated the ability of the dung to suppress the resident vegetation, and the recruitment and establishment of Hycrest seedlings emerging from the dung.

Sheep dung had …


The Influence Of Forest Fragmentation And Landscape Pattern On American Martens And Their Prey, Christina D. Hargis May 1996

The Influence Of Forest Fragmentation And Landscape Pattern On American Martens And Their Prey, Christina D. Hargis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Habitat fragmentation occurs when large tracts of an orginal habitat are replaced by smaller patches of two or more habitat types, largely through human activities. I studied the behavior of six measures of landscape pattern that seemed appropriate for quantifying fragmentation, and used these measures to investigate the effects of forest fragmentation on American martens (Martes americana) and their prey. The measures I selected were edge density, contagion, mean nearest neighbor distance between patches, mean proximity index, perimeter-area fractal dimension, and mass fractal dimension. To test the behavior of these measures with a variety of landscape patterns, I …


Assessment Of Kokanee Salmon, Oncorhynchus Nerka, Genetic Stocks In Flaming Gorge Reservoir, Utah-Wyoming, Michael F. Canning May 1996

Assessment Of Kokanee Salmon, Oncorhynchus Nerka, Genetic Stocks In Flaming Gorge Reservoir, Utah-Wyoming, Michael F. Canning

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I investigated the relative abundance, spatial distributions, return to the creel, and growth rates of two genetic stocks of kokanee salmon, Oncorhynchus nerka, in Flaming Gorge Reservoir, Utah-Wyoming. The two genetic stocks consist of fish from the two major spawning populations of kokanee in the reservoir. One population, Shore Spawners, spawns along the eastern shoreline of the Open Hills area of the reservoir. The other population, Sheep Creek, spawns in Sheep Creek, a tributary located in the Canyon area of the reservoir.

Mitochondrial DNA of kokanee from each population was analyzed to determine haplotype differences between stocks. These haplotype …


The Effect Of Salinity Level Upon The Yield, Root Growth, And Water Extraction Of Contrasting Rooting Subpopulations Of Alfalfa (Medicago Sativa) Under Conditions Of Zero Leaching, Laura A. Vincent May 1996

The Effect Of Salinity Level Upon The Yield, Root Growth, And Water Extraction Of Contrasting Rooting Subpopulations Of Alfalfa (Medicago Sativa) Under Conditions Of Zero Leaching, Laura A. Vincent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A major problem in irrigated agriculture in the Western U.S. is the gradual accumulation of salinity in the plant root zone. These nonuniformly saline soils contain increasing amounts of salinity with depth, and salt accumulation is accelerated in situations where leaching is minimized. Root growth and thus plant yield is limited in these soils due to decreased water uptake. We studied the root growth of two subpopulations of alfalfa differing in their ability to produce fibrous roots to determine if altering root morphology would increase plant yield and water extraction, in an irrigated saline soil.

Soil profiles for a control …


Habitat Selection And Movement Of A Stream-Resident Salmonid In A Regulated River And Tests Of Four Bioenergetic Optimization Models, Mark D. Bowen May 1996

Habitat Selection And Movement Of A Stream-Resident Salmonid In A Regulated River And Tests Of Four Bioenergetic Optimization Models, Mark D. Bowen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A bioenergetics model was constructed for stream-resident drift-feeding salmonids. Model predictions of surplus power (energy available per unit time for growth and reproduction) were not statistically distinguishable from observations of surplus power in three laboratory studies. Of 40 experimental trials in these three studies, the model correctly predicted surplus power in 39 cases (p < 0.05).

I collected observations of rainbow trout (Oncorhynchus mykiss) focal velocity and physical habitat availability in the Green River of northeastern Utah, USA (1988-1990). In the winter of 1988, Flaming Gorge Dam generated hydropower and delivered an lJDStable discharge regime with a higher mean discharge …


Behavioral Characteristics Affect Habitat Selection Of Domestic Ruminants, Cody B. Scott May 1995

Behavioral Characteristics Affect Habitat Selection Of Domestic Ruminants, Cody B. Scott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I evaluated some of the factors affecting livestock distribution by conducting experimental (Chapters II and III) and observational (Chapter IV) studies. In Chapter II, I described the effect of locations of familiar foods and social interactions on choice of feeding location by lambs. Lambs were exposed to a pasture as subgroups of strangers and companions with different dietary habits (i.e., three lambs that preferred milo with three lambs that preferred wheat). Milo was placed on one end and wheat on the other, about 100 m apart. Strangers typically fed in different locations, reflecting dietary preferences. Conversely, companions fed in both …


Disease And Habitat Change As Factors Associated With Mourning Dove Population Decline, William D. Ostrand May 1995

Disease And Habitat Change As Factors Associated With Mourning Dove Population Decline, William D. Ostrand

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The western mourning dove (Zenaida macroura) population has been declining since 1966. Data collected in 1951-52, in Fillmore, Utah, provided us a baseline for comparison with our study in the same area. Our approach was to determine whether a local population decline had occurred since the original data were collected, assess if trichomoniasis has impacted the local population, determine if changes in habitat structure affect foraging site selection, quantify changes in habitat, identify which habitats doves preferred, ascertain whether doves had responded to habitat change by changing food habits, and assess if changes in habitat were responsible in …


Winter Habitat Selection By American Marten (Martes Americana) In Newfoundland: Why Old Growth?, Gary S. Drew May 1995

Winter Habitat Selection By American Marten (Martes Americana) In Newfoundland: Why Old Growth?, Gary S. Drew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although the American marten (Martes americana) generally is recognized as an obligate late-seral species, the factors dictating this association are poorly understood. Martens were studied in Newfoundland, Yellowstone National Park, and in a captive setting. As expected, use of habitat types was not proportional to availability P < 0.001). Defoliated and late-seral conifer stands were used more than expected, while all other types indicated expected or less than expected use. Habitat selection by martens was detectable at spatial scales greater than 80 m (P < 0.001).

Newfoundland martens were radio-collared and monitored for diet activity during the winters of 1990 and 1991. A regression of the percent active fixes on temperature had a negative slope (b = -4.45, P = 0.084, n = 12), indicating that martens did not minimize their exposure to low temperatures. A log-linear model suggested …


The Impact Of A Mountain Pine Beetle Epidemic On Wildlife Habitat And Communities In Post-Epidemic Stands Of A Lodgepole Pine Forest In Northern Utah, William E. Stone May 1995

The Impact Of A Mountain Pine Beetle Epidemic On Wildlife Habitat And Communities In Post-Epidemic Stands Of A Lodgepole Pine Forest In Northern Utah, William E. Stone

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 …


The Effect Of Climate And Spittlebug (Aeneolamia Albofasciata) On Buffelgrass (Cenchrus Ciliaris L.) Productivity In The Sonoran Desert, Martha H. Martin-Rivera May 1994

The Effect Of Climate And Spittlebug (Aeneolamia Albofasciata) On Buffelgrass (Cenchrus Ciliaris L.) Productivity In The Sonoran Desert, Martha H. Martin-Rivera

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I conducted field studies during 1984-1988 to determine how (1) precipitation amount and distribution affect buffelgrass [Cenchrus ciliaris L. (Link) l productivity, (2) summer rainfall amount and distribution and temperature influenced the spittlebug (Aeneolamia albofasciata Lalleman) life cycle, and (3) summer burning affects spittlebug densities and buffelgrass productivity.

Experiment I was conducted from 1985 through 1988. Forage samples collected at 15-day intervals were separated into live, recent-dead standing, old-dead standing, and litter. There was a positive relationship between the summer precipitation and the live biomass. Recent-dead standing and old-dead standing decomposed during the summer, fall, or spring.

Experiment …


Influence Of The Ruminant Digestive Process On The Germinability Of Range Forage Species, Mohammed S. Al-Mashikhi May 1993

Influence Of The Ruminant Digestive Process On The Germinability Of Range Forage Species, Mohammed S. Al-Mashikhi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ingestion and dispersal of seeds of desirable species by domestic livestock is potentially important as a range improvement practice, but the passage of seed by livestock has only been studied in a fragmented way, particularly for species adapted to rangelands of western North America. The objectives of this research were to examine the effects of different periods of exposure to in vitro and in vivo digestion processes in cattle on the germinability of several grass species, and determine if the in vitro incubation technique is a good predictor of seed fate following passage through the ruminant digestive tract.

Seeds of …


Relationships Among Birds, Willows, And Native Ungulates In And Around Northern Yellowstone National Park, Sally Graves Jackson May 1992

Relationships Among Birds, Willows, And Native Ungulates In And Around Northern Yellowstone National Park, Sally Graves Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although the impacts of livestock and human activities on riparian zones and associated wildlife have been well documented, little is known about the impacts that browsing by large native ungulates such as elk and moose may have. In the northern Yellowstone area, some willow stands experience intense browsing by elk and moose whereas others experience medium or very low amounts of browsing. The objectives of this study were (1) to compare the species and densities of birds among willow stands that have experienced different intensities of browsing by native ungulates, (2) to measure the relationship between five species of birds …


Optimization Of Ranch Management Alternatives In Utah, Scott G. Evans May 1992

Optimization Of Ranch Management Alternatives In Utah, Scott G. Evans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to determine the optimum combination of various cattle production, range forage, and crop harvesting alternatives available to ranch owners and managers in Utah. While many promising alternatives are available, determining which alternatives to implement is difficult because the total ranch operation must be considered.

Linear programming (LP) is a tool available to ranch managers which allows the profit maximizing combination of improvements to be easily determined. LP allows ranchers to examine the entire ranch operation and to reduce the amount of risk and uncertainty involved in the decision making process.

The typical Utah ranch …


Dynamic Multi-Species Animal Habitat Modeling With Forest Succession Models, Stephen A. Compton May 1992

Dynamic Multi-Species Animal Habitat Modeling With Forest Succession Models, Stephen A. Compton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research determines and demonstrates the ability to simulate dynamic multi-species animal habitat suitability with forest succession models. A literature review of dynamic animal habitat models is presented. The structure of an existing forest simulation model (MASS10) was modified from a basal area-based model to a volume-based model (DYNAM10). The forest model was calibrated using data from permanent-plot growth and vegetation samples collected by USDA Forest Service Forest Survey procedures. The theoretical growth parameters used to simulate stand development were validated. Predictions of DBH and height growth, as well as stand-level behavior, were verified. A subroutine, VEGDYN, was added to …