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Leaf Epidermal Transmittance Of Ultraviolet Radiation And Its Implication For Plant Sensitivity To Ultraviolet-Radiation Injury, Ronald Robberecht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Leaf epidermal transmittance of ultraviolet radiation (280-400 nm) was examined in several plant species to determine the capability of the epidermis to attenuate solar ultraviolet radiation. Epidermal samples were mechanically isolated and examined with a spectroradiometer/integrating sphere for transmittance. A survey of 25 species exposed to natural insolation was conducted. Although the species differed in life form, habitat type, and epidermal characteristics, epidermal transmittance was generally less than 10%. Ultraviolet radiation was attenuated 95 to 99% in more than half of the species. In 16 species, flavonoid and related pigments in the epidermis accounted for 20 to 57% of the …

Feeding Behavior Of Pen Reared Mule Deer Under Winter Range Conditions, Michael A. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the feeding responses of mule deer to a system of spring livestock grazing. The specific purposes were 1) to determine botanical composition of diets selected by mule deer on a winter range subjected to previous spring grazing by sheep compared to one with no sheep grazing and 2) to develop a basis for predicting selection of individual plants by deer, based on physical characteristics of the plants and the species and physical proximity of associated plants.

The study was conducted within the framework of a completely randomized experimental design with two treatments. Variables controlled for each unit …

Photosynthesis, Dark Respiration, And Growth Of Rumex Patientia L. Exposed To Uv-B (280-315 Nm) Irradiance Corresponding To Reduced Atmospheric Ozone Concentrations, William B. Sisson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Net photosynthesis, dark respiration, chlorophyll concentrations and growth were determined for Rumex patientia L. exposed to UV-B radiation corresponding to reduced atmospheric ozone concentrations. The hypothesis of whether reciprocity is maintained in the response of R. patientia to polychromatic UV-B radiation was tested. On the basis of the relationships derived from these studies, a simulation model was developed for the prediction of photosynthesis and growth of R. patientia exposed to UV-B radiation corresponding to any atmospheric ozone reduction.

Photosynthetic rates were found to be depressed after two hours exposure to UV-B irradiance simulating a 0.18 atm·cm ozone column when the …

Socioecology Of The Vicuna, William L. Franklin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The social organization of the vicuna (Vicugna vicugna) and its relationship to the environment were studied at the Pampa Galeras National Vicuna Reserve in southern Peru from May 1968 to April 1971. Behavioral data were collected on groups within a grid of 12.4 km² during 3,800 hours of observation. The vicuna's alpine grassland environment was characterized by greatly fluctuating and freezing temperatures, light precipitation, high evaporation, wind, short growing seasons, shallow and infertile soils and low plant production. Vicuna habitat quality was dependent upon high producing, preferred vegetation types and close access to permanent water and a …

Food-Searching Behavior Of Free-Living Ferruginous Hawks: Factors Affecting The Use Of Hunting Methods And Hunting Sites, James Stuart Wakeley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Food-searching behavior of two adult male Ferruginous Hawks (Buteo regalis) was studied by direct observation in Curlew Valley, Utah-Idaho, during the nesting seasons of 1974 and 1975. This paper analyzes the effects of vegetation type, prey distribution, cover density, previous experience, and time and energy budgets upon the predators' choice of hunting methods and hunting sites.

Both hawks hunted actively throughout the day (0600 to 2100 hours MDT). Male 1 (1974) and Male 2 (1975) captured an average of 8.7 ± 2.0 and 9.0 ± 1.5 prey items per day, respectively, during the 4-wk observation period in each …

Forage Selection And Nutrition Of Sheep And Goats Grazing In The Tunisian Pre-Sahara, Rudolfo Ricardo Griego

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nomadic pastoralism has been the traditional method of utilizing grazing resources in arid and semi-arid regions of Africa. However, increased sedentarization accompanied by growing human and animal populations during the past two decades is thought to be accelerating the desertification process, or desert expansion. The specific interactions of the grazing animal with this process has been speculated upon but not studied in detail. A comparative study was initiated during the spring grazing season of 1974 to determine sheep and goat nutritional and production responses, as well as patterns of vegetative selection and utilization under the pastoral system currently employed in …

Food Interactions Between Utah Prairie Dogs And Cattle, Dennis Crocker-Bedford

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the food interactions between Utah prairie dogs (Cynomys parvidens, Allen) and cattle (Bos taurus). During 1974 and 1975, three prairie dog colonies near Panguitch, Utah, were studied intensely: "Oldfield" was chosen to represent colonies near fields of alfalfa (Medicago sativa); "Lowercrested" was chosen to represent colonies below 2,200 meters above sea level (a.s.l.) which were not near alfalfa, and "Uppercrested" was chosen to represent colonies above 2,200 meters a.s.l. which have been planted with crested wheatgrass.

Visual observations were made of Utah prairie dogs to determine their diets. Livetrapping of prairie …

Model Studies For Molybdenum Enzymes. The Reduction Of Cytochrome C By Molybdenum(V)-Cysteine Complexes, Glen D. Lawrence

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The reduction of ferricytochrome c ( cyt c^III), as well as some iron ligand complexes and chemically modified derivatives of cyt c^III, by two molybdenum(V)-cysteine complexes has been investigated as a model for electron transfer in molybdenum enzymes. The reduction of cyt c^III by di-μ-oxo-bis [oxo(L-cysteinato)molybdate(V)] (I) is first order in cyt c^III and zero order in I over a wide range in concentration of I at neutral pH. The reduction of cyt c^III by μ-oxo-bisfoxodihydroxo(L-cysteinato) molybdate(V)] (II) is first order in both reactants and has a rate several orders of magnitude greater …

Ecological Management Of The Alfalfa Leafcutter Bee, Megachile Pacifica (Panzer), With Emphasis On Diapause Induction, Ron M. Bitner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of photoperiod and temperature on diapause induction in the alfalfa leafcutter bee, Megachile pacifica (Panzer) (=M. rotundata Auct.), were studied during the summers of 1972, 1973 and 1974, The influence of photoperiod and temperature on mortality, rate of development and incidence of diapause was measured during the developmental stages of this insect. The aim of this research was to assess the potential for manipulation of the number of generations of this bee per season so as to develop a practical and ecologically-sound method of management,

Eggs, larvae, pupae and adults of M. pacifica were subjected to regimens …

Studies Of Evaporational Cooling In An Apple Orchard, Stephen W. Zsiray Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the spring, apple orchards are susceptible to freeze damage. Various approaches to orchard protection have been used in the past. Overhead sprinkling for bloom delay has been effective in extending to a later period in the spring the freeze hardiness of apple buds. Thus, protection against a late spring freeze is obtained. Previous research has not been conducted to determine optimum sprinkling times in the spring, the most effective threshold temperature, the amount of water needed to provide adequate bud protection, and the daily length of sprinkling time.

A 2-year investigation was conducted with the objective of obtaining basic …

Corn Yields As Influenced By Irrigation Levels During Different Growth Stages, G. Dennis Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Corn dry matter and grain yields were evaluated for 40 unique limited irrigation treatments and compared to a standard nonlimited treatment. The various treatments were imposed by an interaction of time (i.e., growth stage) and water level . Irrigation was so scheduled that each treatment received water at evaporative demand rates during either the vegetative or the pollination stage . The total irrigation water applied for the growing season ranged from 11 em to 43 em.

Dry matter and grain yields were essentially the same for all treatments. Limited irrigation in the vegetative stage did not reduce growth if there …

Riparian Environmental – Vegetation Interrelationships Along The Lower Escalante River Glen Canyon National Recreation Area, Utah, James R. Irvine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies of environmental and riparian vegetation interrelationships along the lower Escalante River were conducted during 1974 and 1975. The study area included the Escalante River flood terrace between Harris Wash and Coyote Gulch.

Methods were developed compatible for wilderness use. Sixty-nine 1 x 10 meter macro-plots were taken at 23 locations. Measurements were taken of major environmental parameters thought to influence riparian vegetation: stratigraphy, soil texture and moisture, river bank angle and aspect, and height and width of flood terraces.

Canyon profile was found to be strongly influenced by geologic strata. Resistance to erosion by these strata determines canyon fluctuations …

Plant Demographic Studies Of Tall Threetip Sagebrush-Grass Vegetation On The Eastern Snake River Plains, Idaho, Kenneth Harold Rea

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It has commonly been assumed that grazing decreases the longevity of plants, however, very few studies address this question. Knowledge of mean age, longevity and other aspects of population dynamics would help improve estimates of productivity and nutrient cycling and aid understanding of range condition and trend. These data would also aid in developing a theory of community organization and control.

As a step toward these ends, pantograph records from twelve 1 m² plots established at the U. S. Sheep Station on the Snake River Plains of southeastern Idaho between 1923 and 1935 were examined. The plots were mapped …

Plant Demographic Studies Of A Desert Annuals Community In Northern Utah Dominated By Nonnative Weedy Species, David R. Duba

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Field and laboratory investigations were conducted relating to factors controlling distribution and abundance of annual species growing in a disturbed portion of the salt desert shrub zone on fine-textured soils. Dominant species on the site in the two study years were the nonnative, Halophytic, late-summer maturing, Halogeton glomeratus (Bieb.) C.A. Mey., and Bassia hyssopifolia (Pall.) Kuntze. Contrasting amounts of precipitation were received in the two years; in 1974, spring conditions were so dry that two early-maturing, sub-dominant annuals, Descurainia pinnata (walt.) Britton, and Lepidium perfoliatum L. were essentially absent. They successfully reproduced under more favorable 1975 conditions.

Studies on species …

The Effects Of Chemical And Cultural Treatments On Gibberellin Levels In Strawberry Leaves And On The Induction Of Secondary Flowering, Richard N. Arteca

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gibberellins 3, 4 and 7 were isolated from "Shasta" Strawberry (Fragaria X ananassa Duch.) leaves and identified by gas and thin layer chromatography. In young expanding leaves GA₃ occurred at 5 times the concentration of either GA₄ or GA₇.

CCC (2-chloroethyl-trimethylammonium chloride), SADH (Succinamic acid-2,2-dimethyl hydrazide), ethephon (2-chloroethylphosphonic acid), and UBI-P293 (2,3-dihydro-5-6-diphenyl-1,4-oxathiin) were applied to established plantings of three June-bearing strawberry (Fragaria X ananassa Ouch.) cultivars: 11 Shasta, 11 "Fresno" and "Tioga." Treatments were applied on alternate days for three weeks following anthesis of the king blossom. Levels of GA₃ and GA_{4 …}

Aerial Photography In Estimating Waterfowl Populations In Northern Utah, Timothy H. Provan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this project was to evaluate effectiveness of aerial photography as a waterfowl census technique. An aerial photographic pattern was formulated and tested during the spring and fall months of 1971 and 1972 at Ogden Bay Waterfowl Management Area, Weber County, Utah. The reliability and feasibility of the technique for censusing waterfowl proved effective and practical.

Eight flights per season, 4 routes per flight, and 30 photos per route taken over unit 1 of the Ogden Bay Waterfowl Management Area was the experimental design or pattern for the study. The level of accuracy and the cost involved with …

The Horse Population Of Utah And Its Impact, Scott Stewart Mckendrick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

PART I

The horse numbers of Utah had not been accurately counted since the early 1960's. It was estimated that horse and pony numbers were reaching heights as recorded before the age of tractors and automobiles. Horsemen in Utah were asking for financial assistance for public horse facilities from the Utah legislature. The first part of this study was to survey the horse population to determine an accurate count of Utah horses.

PART II

In order to be satisfied that the horse industry deserved the spending of public funds, it was necessary to know the economic contribution of the horse …

A Computer Approach To Performing Mppa Testing, James W. Shaw

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

In the highly competitive cattle market of today a scientific method, by which a rancher can base a judgement, moderated by experience as to which animals are to be kept, as proven by superior performance, can be a valuable asset.

This record performance testing system was designed to demonstrate the value of adequately kept records. Its purpose is to help ranchers develop records of herd performance, inventory, and improve management practices by more informed decisions. The system, through its representative, provides a means by which ranchers can obtain information on new ideas in animal production, health, sanitation, nutrition, management practices, …

An Economic Analysis Of Sprinkling For Bloom Delay And Freeze Protection Of Apples In Farmington, Utah, Jay Val Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The major purpose of this study is to analyze the economic feasibility of bloom delay by sprinkling as a means of protecting delicious apples from frost. The framework of this study is based on decision making theory under uncertainty. It demonstrates the usefulness of the Bayesian approach to determine optimum action to take in face of uncertain climatic conditions. The economic analysis was conducted for Farmington, Utah, where significant relationships were found between the end of winter rest (end of chill-unit accumulation) and time of full bloom of red delicious apples.

A posteriori probabilities for the state of nature were …

Relationships Between Terrestrial Vertebrate Fauna And Selected Coniferous Forest Habitat Types On The North Slope Of The Uinta Mountains, David S. Winn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives were (1) to relate terrestrial vertebrate responses to the management practices used for lodgepole pine forests within the Barometer Watershed, Mountain View Ranger District, Wasatch National Forest, Utah. (2) To correlate terrestrial vertebrate densities or frequencies with community types, edge, major forest stand structures, and (3) to propose management plans to manipulate densities of major vertebrate species in a predetermined manner.

The study was conducted between 1973-1975 and provides a detailed description of forest vegetation for 53 lodgepole pine (Pinus contorta) stands. For each of these stands, a complete summary is provided of tree populations, coverage, …

Demographic Analysis Of A Utah-Idaho Coyote Population, Jeffrey J. Knudsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I estimated various demographic parameters of the coyote population in Curlew Valley, northern Utah and southern Idaho, during the period August 1972 through September 1974. Field work provided estimates of relative and absolute coyote densities and established causes of coyote mortality. Laboratory analyses of 866 coyote carcasses supplied information on sex and age ratios, ovulation frequencies, pregnancy rates, and litter sizes.

Annual ovulation frequencies and pregnancy rates for the entire population varied from 70 to 92 percent and 57 to 88 percent respectively. Age-specific ovulation frequencies varied from 63 to 91 percent, respectively, for pups and adults. Similarly, age-specific pregnancy …

Reproduction By Adfluvial Salmonids In Spawn Creek, Cache County, Utah, David R. Bernard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The migration and production of indigenous populations of brown, brook, and cutthroat trouts in Spawn Creek, Cache County, Utah, were studied in 1973 and 1974 to elucidate the role of this stream vis-a-vis the rest of the watershed. Spawn Creek and its watershed were described climatically, hydrologically, geologically, vegetatively, recreationally, and chemically. The prevalent, aquatic taxa of fauna and flora were also listed. The equipment and techniques used in the study to collect data, including a two-way fish trap and electro-fishing gear, were delineated. The collected data consisted of periodic estimates of mean weight and density stratified by year classes. …

Insect Consumption Of Seeded Rangeland Herbage In A Selected Area Of Diamond Fork Canyon, Utah County, Utah, Diane M. Bowers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study compares insect and cattle consumption of crested wheatgrass (Agropycon spp.) on a site in Sterling Ranch, Utah County, Utah. The hypothesis tested is that insect consumption in general, and specifically consumption by Labops hesperius Uhler, significantly reduces total available cattle forage.

Labops and grasshoppers were probably the major cause of secondary damage at the study site, while the impact of thrips is unknown. A detrimental impact on range was suggested by the data, as insects consumed forage equivalent to 2.8 animal units per month, while cattle consumed forage equivalent to 2.1 animal units per month at the …

Seasonal Patterns Of Photosynthesis And Respiration In Atriplex Confertifolia And Ceratoides Lanata, Richard S. White

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Net photosynthesis and dark respiration studies were conducted on Atriplex confertifolia (Torr. and Frem.) S. Wats and Ceratoides lanata (Pursh) J.T. Howell under field and laboratory conditions. These woody species are commonly found in salt desert shrub communities of the Intermountain West. During these investigations, the effects of air temperature, plant moisture stress, soil water potential, irradiation, and plant phenological status were examined with respect to their influence on carbon dioxide (CO₂) exchange.

Intensive field studies were carried out between April and October. This interval corresponded to the major period of physiological activity in both species. The factors …

Water Allocation For Future Development In The Uintah Basin, David W. Mills

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The major objectives of this study are to determine whether or not future needs for water in the Uinta Basin can be satisfied by the present quantity of water produced by the hydrology of the Basin.

The specific objectives are as follows:

1. To determine the present demand for water in the Basin.

2. To determine the present annual quantity of water produced by the Basin.

3. To project the changes in the demand for water in the Uinta Basin resulting from energy, agricultural and other development.

4. To project the changes in the quantity of water available to satisfy …

Breeding Biology And Pesticide-Pcb Contamination Of Western Grebe At Bear River Migratory Bird Refuge, Mark L. Lindvall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The breeding biology of western grebe was studied at Bear River Migratory Bird Refuge, Utah in 1973 and 1974. More than 300 nests were located and data gathered on nesting habitat and success. Western grebe at Bear River selected nest sites for nearness to open water of approximately 30 em in depth. At least one young was hatching in 21 percent of the nests. Avian predation and abandonment of nests following drops in water levels caused the greatest loss of nests. Chlorinated hydrocarbons monitored in western grebes showed DDE, DDD, PCB, 1260, and PCB 1254 levels in 24 breast muscle …

A Hydrology Temperature Model For A Small Mountain Watershed, Charles Wilson Pettee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A small mountain watershed located in the Wasatch Mountains of North Central Utah is calibrated to a lumped, deterministic simulation model which is capable of predicting daily streamflow and stream temperature. The input information required is daily precipitation and maximum and minimum air temperatures.

In this study, the area of watershed modeling is reviewed in general and as it specifically applies to the study watershed.

The degree of correlation between observed data and predicted output is only mediocre. The model remains unverified for streamflow prediction and is poorly verified for stream temperature.

Productivity Of Two Utah Deer Herds As Related To Nutrition, Clarence Leon Pack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study of mule deer occupying deer management units 53 and 54 in south central Utah was conducted from August, 1971 to May, 1974 to determine food habits, caloric requirements, dietary nutritional levels, and productivity. Transects, fecal analyses, weight data, classification counts, and forage analyses were used to accomplish these objectives.

Food habits of deer on the two units were similar, except for higher use of scrub oak on unit 53 and higher use of snowberry on unit 54.

Deer on unit 54 were significantly larger than those on unit 53. Thus, their caloric requirements also were significantly higher.

Deer …

Nesting Ecology Of The Redhead Duck On Knudson Marsh, Utah, Thomas Claud Michot

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Redhead duck (Aythya americana) nesting and habitat change was studied in Knudson Marsh, Utah, in 1974 and 1975, and compared with earlier studies from 1950 and 1955 on the same marsh. Water conditions in 1975 were found to be similar to those in 1950, both years of favorable habitat, yet there was a decline in numbers of redheads from 500 pairs in 1950 to 50 pairs in 1975. The number of nests found also declined from 151 in 1950 to 49 in 1975. Water conditions were poor in 1955 and slightly more favorable in 1974, but there was …

The Anti-Thyroid Effects Of Halogenated Phenols And Pyridinols, Leland Steven Beck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research was initiated to determine the mechanism(s) of action that could explain increased weight gain and decreased milk production in dairy cattle fed corn silage containing residues of certain organophosphate pesticides. It was proposed that the mode of action involved and alteration of thyroid physiology by the metabolites of the pesticides, namely halogenated phenols. Studies were carried out to determine the effect of tri-halogenated phenols and pyridinols upon T₄-binding to bovine serum albumin (BSA) and to liver mitochondria isolated from male rats. Using the rat as a model, feeding trials were performed to determine the effect of …