Ecology and Evolutionary Biology Commons^™

Economic Analysis Of Long-Term Management Strategies For Two Sizes Of Utah Cattle Ranches, Roger E. Banner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah cattle ranchers realize relatively little profit from ranch ownership and management. This study represents an attempt to identify ranch management strategies that produce more profit over time than do conventional strategies.

To identify optimum management strategies for the long term, analyses of ranches under both normal and adverse ranch operation conditions using the COPLAN linear programming model were made for strategy comparison. To depict these ranch business environmental conditions, production levels were estimated from available biological data and price levels were estimated by indexing 1977 ranch product prices (the most current budget data available for Utah). The variability of …

Effect Of Mild Water Stress And Enhanced Ultraviolet-B Irradiation On Leaf Growth Of Rumex Obtusifolius L. And Rumex Patientia L. (Polygonaceae)., Steve R. Holman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Leaves of Rumex obtusifolius L. and R. patientia L.were exposed to combinations of mild water stress and enhanced ultraviolet-B irradiation during their ontogeny. Two UV-B treatments (enhanced UV-B and control) and three water stress treatments (-0.0 MPa, -0.2 MPa and -0.4 MPa rooting medium matric potentials) were employed. The impact of the stress interaction was assessed on the basis of changes in leaf area, average adaxial epidermal cell size, and total number of adaxial epidermal cells per leaf. Although the level of UV-B irradiation applied was insufficient to significantly alter leaf growth at any given water stress, UV-B did interact …

The Energy Expenditure Of Heifers Grazing Crested Wheatgrass Rangeland In West-Central Utah, Kris M. Havstad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The free-roaming ruminant requires energy for the demands of vii grazing, traveling and thermoregulation that are not required by its confined counterpart. Literature estimates of these additional costs range from 10 to 170 percent above maintenance. The uncertain magnitude of this increased demand and the factors that contribute to it impede the ability of the rangeland ruminant nutritionist to establish guidelines for the energy requirements of the free-roaming herbivore. This study was designed to estimate the energy expenditure of yearling Angus heifers while grazing a declining supply of available crested wheatgrass forage (Agropyron cristatum) on rangeland in west-central …

Effects Of Host Plant Patch Size And Surrounding Plant Type On Insect Population Dynamics, Lynn A. Maguire

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of the present study was to investigate how plant spatial patterns and insect behavior interact to influence the population dynamics of insects using the plants. The study included three phases: l) field experiments using collards (Brassica oleracea) and the crucifer insect fauna; 2) simulation models representing the population dynamics of an insect herbivore as functions of insect dispersal behavior and host plant patch size; and 3) model-field syntheses integrating model predictions and field variability estimates to choose an appropriate spatial scale for future field experiments or applications.

In field experiments on surrounding plant type, collards were …

The Effect Of Exploitation On Some Parameters Of Coyote Populations, Robert P. Davison

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The study was conducted to examine the effect of exploitation on population parameters of coyotes (Canis latrans). Hypotheses tested were: (1) Substantial levels of exploitation do not change spring and fall coyote densities significantly; (2) Coyote recruitment (reproduction and immigration) rates are unaffected by substantial levels of exploitation; (3) Annual coyote survival rates are not related to intensity of harvest rates; (4) Coyote emigration rates remain unchanged by substantial levels of exploitation. Coyote demographic parameters were measured from 1975 to 1978 for a treatment population subject to substantial exploitation (Curlew Valley, Utah and Idaho), and for an unexploited …

An Analysis Of A Measure Of Productivity In Mule Deer Populations, Ronald J. Ryel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to investigate the relationship between the fall proportion of fawns among fawns and does in a mule deer population and two measures of productivity, the spring recruitment rate and the reproductive performance as measured in the fall. The spring recruitment rate was defined to be the number of fawns per doe which were recruited into the population at 1 year of age. The reproductive performance was defined to be the number of fawns produced per doe 2 years or older which survive to a specified time. The relationships between these quantities were measured by …

Resource Partitioning In Breeding Populations Of Marsh Hawks And Short-Eared Owls, Susan C. Linner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During the 1979 breeding season four pairs of northern harriers, or marsh hawks (Circus cyaneus) and four pairs of short-eared owls (Asio flammeus) were studied in Cache Valley, Utah. The study was concerned solely with diurnal resource utilization, and did not examine the owls' nocturnal activities. The home range of each harrier pair overlapped substantially with that of an owl pair. Percent habitat overlap for hawk-owl pairs varied from 39 percent to 72 percent. Observations were made to determine if differences existed in their utilization of habitat and food resources, or in their daily and seasonal …

Production Of Mountain Whitefish (Prosopium Williamsoni) In Altered And Unaltered Reaches Of Two Intermountain Streams In Their Alluvial Flood Plains, Michael J. Ottenbacher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimates of production and related parameters (growth rate, density, standing crop) were made for populations of mountain whitefish in altered and "unaltered" areas of the Blacksmith Fork and Logan River, Utah from spring 1975 through summer 1976. Capture records of marked whitefish were also analyzed to describe fish movement and check on assumptions implicit in the population estimator.

Mean weights and instantaneous growth rates of whitefish were similar at all sites for comparable size/age groups. Among sites, differences in production per sampling interval and annual production were due mainly to differences in standing crop and/or age structure.

Estimates of mountain …

Effects Of Forage Availability On Voluntary Intake And Feeding Behavior Of Grazing Heifers, Anastasios S. Nastis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forage intake by animals is an important factor in determining production of livestock products from rangelands. However, relatively little is known of effects of such forage variables as availability and distribution in space upon intake. Even less is known about how the grazing animal modifies its feeding tactics when confronted with diminishing or limited supplies of available forage and how such altered behavior may affect the animal's energetic cost for existence. Forage intake, body weight gain, grazing time and biting rate of Angus heifers was related to forage availability and plant height on semiarid crested wheatgrass rangeland during the late …

Spectral Signature Studies For Application In Deer Census Using Remote Sensing Techniques, Maran C. Pate

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was performed to determine the spectral signatures of deer and their natural background elements for censusing purposes. Consideration was given to atmospheric transmittance, acceptable flying weather, and terrain. Possible spectral bands between 0.3 and 14.0 μm were obtained (over a pathlength of 1500 feet at an altitude of 5000 feet) based upon atmospheric transmittance using the LOWTRAN 3B computer program. They are: 0.30 - 1.33, 1.49 - 1.79, 2.00 - 2.50, 3.00 - 3.16, 3.38 - 4.10, 4.59 - 5.05, and 8.00 - 13.33 μm, for transmittance greater than 75%. Weather conditions are favorable for flying and taking …

Growth Of Phytophthora Infestans Race 1.2.4 And Synthesis Of Steroid Glycoalkaloids By The Fungus In Synthetic Media, Melanie R. Maas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A chemically defined synthetic medium was developed in which Phytophthora infestans (Mont.) de Bary race 1.2.4 grew extensively. This medium consisted of: 90.0 grams maltose, 20.0 grams DL-alanine, 20.0 grams L-proline, 1.0 gram KNO₃, 0.5 gram KH₂PO₄, 0.25 gram MgSO_4. 7H₂O, 1.0 milligram thiamin per liter of distilled water. The average level of growth in this medium was 0.5864 gram dry weight mycelium per 50 milliliters medium.

The glycoalkaloids, solanidine and solanine, were synthesized by Phytophthora infestans in the above medium with 62.5 percent of the samples positive and an overall …

Population Limitation Of Jackrabbits: An Examination Of The Food Hypothesis, William R. Clark

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The study was conducted to examine the importance of forage resources in limiting peak population density of black-tailed jackrabbits (Lepus californicus). The research design combined field studies of jackrabbit diet and vegetation impact with computer simulation of herbivore nutrition and population dynamics. The relationships between available forage, dietary intake, energy and protein balance and population changes were compared for high and low population density. Hypotheses tested were : (1) Dietary composition is unaffected by availability above 10 kg/ha; (2) Jackrabbits do not require more forage than is available at high population densities; (3) Dietary composition is not significantly …

Interrelationships Between Benthic Macroinvertebrates And Habitat In A Mountain Stream, John M. Payne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study to determine habitat differences of benthic macroinvertebrates was conducted on the upper Strawberry River, Utah. The investigation was part of a large scale project to determine minimum stream flow requirements for trout. The effects of time, habitat, depth and velocity on the distribution of benthic fauna were evaluated.

Samples of benthic invertebrates (146 total) were collected every 2 months at 8 stations on the river from November, 1975 through August, 1976. Representatives of 59 taxa were collected. Eight taxa comprised 90 percent of the mean annual community standing crop in numbers. Biomass was not dominated by any group …

Biology, Reproductive Potential And The Impact Of Fishing Pressure On The Bluegill Fishery Of Pelican Lake, Uintah County, Utah, Bob D. Burdick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain aspects of the biology of two species of fish, bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides), and the assessment of fishing pressure upon the sport fishery of Pelican Lake, Uintah County, Utah, a 680 ha warmwater lake, were studied between April 1, 1976 and June 30, 1978. The growth rate of bluegills (sexes combined) was fairly rapid; the mean back-calculated total lengths from ages one through nine were 55, 112, 166, 194, 211, 229, 245, 256 and 259 mm. The growth of largemouth bass was 104, 194, 271, 316, 350, 405 and 416 mm …

Development And Validation Test Of A Mule Deer Habitat Rule, Glenn Gephart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mathematical description of Rocky Mountain mule deer (Odocoileus hemionus hemionus) habitat was developed and subjected to validation testing using correlation and multiple regression statistical techniques. Data were collected on a central Utah study area, which was divided into mountain and desert regions.

Data on deer utilization and several habitat components from 86 study plots visited in 1976 were used to develop a habitat rule. Data from 46 study plots visited in 1977 were used to test the accuracy of the rule. Deer utilization was determined from pellet group counts on 20 0.001 ha pellet plots at each …

Information Transfer And Regulation In A Model Ecosystem With Environmental Stochasticity, M. Mckee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The concept of regulation in ecosystems has been given considerable attention in the ecological literature, but no formal treatment has been offered. This study proposes a rigorous definition of regulation which is derived from the mathematics of information and communication theory. A theoretical, mathematical equivalent of the definition is also offered which implies serious limitations as to the value of most traditional laboratory population studies and deterministic population models in understanding regulation in ecosystems. The empirical validity of this theoretical equivalence is tested through use of a competition model of two diatoms. Other observations concerning the relationship between environmental variability …

Some Effects Of A Grazer, Hyalella Azteca On Ecosystem Level Properties In Aquatic Microcosms, Martin D. Werner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study to determine some ecosystem level effects of an aquatic invertebrate grazer, Hyalella azteca, was performed in aquatic ix microcosms. Impact of the grazer was assessed in three general areas: 1) inorganic nutrient levels of the microcosm water column, 2) productivity and respiration of the biotic community, and 3) plant community composition in the microcosms.

The grazing amphipod caused inorganic phosphorus and nitrogen (except ammonia) levels to be elevated in the microcosms. The increase was due, at least partially, to excretion of nutrients into the water by the amphipod. The presence of H. azteca did not significantly …

Two Basic Methodological Choices In Wildland Vegetation Inventories: Their Consequences And Implications, Donald Alan Shute

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In designing inventories of wildland vegetation, two of the many basic methodological choices are: 1) whether data are collected, reduced, and stored in discrete classes or as continuous variables, and 2) whether data are gathered as general purpose variables to bear upon many questions, or as specific purpose variables optimized for only one type of prediction. The effects of these two choices on accuracy of vegetation inventories to predict plant community production were examined by comparing regression models built upon differing sets of independent variables "inventoried" from a common data base. Contrary to expectations, discrete variables of classified community types …

Changes In Spider Community Attributes Along A Subalpine Successional Gradient, Gerald Norman Waagen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The spider communities of four stages of a successional sere leading to and including spruce forests were studied in northern Utah. Four seral stages were recognized. These include: meadows, aspen (Populus tremuloides) stands, subalpine fir (Abies lasiocarpa) forest, and the climax Engelmann spruce (Pica engelmanii) forests.

During the snow-free periods of 1976, 1977 and 1978, 15,987 spiders were collected by three methods including: pitfall traps, by beating vegetation, and with sweep-net samples. Additionally, 1600 15-second intervals of behavioral observations, and measurements of 182 web locations were made.

Of 99 species collected, 44 were considered …

An Investigation Of Salinity Fluctuations In Soils Of A Northern Utah Marshland, Gary Roy Newman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ogden Bay Waterfowl Management Area is one of many marshlands bordering the Great Salt Lake that are extremely important as breeding habitats for North American waterfowl. Salinity, both of surface and interstitial waters, is an important factor in maintaining a suitable habitat within the marsh. For this reason, a study was undertaken to determine the factors affecting the salinity of surface and interstitial waters. A small (approx. 100 acre) subunit was studied extensively to determine; 1) variations in surface water salinity with flowrate and water level; and 2) variation in interstitial water salinity with depth and location within the subunit. …

A Discriminant Function Model Of Gray-Headed Junco Habitat, Andrew R. Grainger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents a description of gray-headed junco habitat in the form of a model based on discriminant function analysis. Junco nests were found by searching randomly located grids on a 7.8 km² study area in central Utah. Vegetation data was gathered on 500 m² circular plots surrounding nests and contrasted with similar data from searched grids where nests were not found. The model explains 28 percent of the between-groups variance and correctly classifies 68 percent of the plots.

Plant cover types are good predictors of areas where gray-headed juncos nest, while plant community type descriptions do not …

Plant Succession Studies On Subalpine Acid Mine Spoils In The Beartooth Mountains, Patricia Lea Howard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Large areas within alpine and subalpine tundra have been by disturbed by mining during this century. The most promising method for retarding deterioration of these areas is revegetation with native species through both seeding and transplants. One natural process of revegetation which occurs on portions of many existing disturbances seems to be the establishment of a few species that expand with time to form matts of plants.

At the McLaren Mine, located at 3000 m elevation in the Beartooth Mountains, Montana, active succession is occurring and is dominated by Carex species. Seed viability and successional patterns studies were conducted on …

Influence Of Spring Sheep Grazing On The Forage Intake And Quality Of Diets Consumed By Pen-Reared Mule Deer Under Winter-Range Conditions, Kenneth Owen Fulgham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the nutritional responses of mule deer during winter on range subjected to a system of spring livestock grazing. The specific purposes were 1) to determine the quality (crude protein, digestible energy, and digestibility) of diets consumed by mule deer in winter on ranges grazed and ungrazed by sheep in spring, 2) to determine the level of forage intake, as determined by the external indicator chromic oxide, for deer under the same grazing regimes, 3) to compare forage intake estimates determined by the external indicator (chromic oxide) with results obtained by ocular estimation, and 4) to determine the …

The Social Behavior Of Brown Bears At Mcneil River, Alaska, Allan L. Egbert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The social behavior of brown bears (Ursus arctos) was studied during the summers of 1972 and 1973 as bears fished for salmon at McNeil River, Alaska. Study objectives were to determine behavioral characteristics of bears in relation to sex and age, changes in social behavior over a 40-day long fishing season, social and environmental parameters correlated with the occurrence of behavior, and to test the hypothesis that brown bears modify social behavior in a feeding aggregation to exploit a resource limited in time and space.

Over one-half of the agonistic interactions consisted of passive deferrals. Encounters that included …

The Role Of Vegetation Architecture In Determining Spider Community Organization, Cynthia L. Hatley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The relationships between vegetation architecture and spider community attributes were examined in a big sage (Artemisia tridentata) community. Spiders were separated into guilds using similarities of species' hunting behavior. Shrub architecture was experimentally manipulated in the field by either clipping 50% of a shrub's foliage to decrease foliage density or tying together a shrub's branches to increase foliage density.

Temporal patterns of spider species density, diversity (H') and evenness (J') showed midsummer peaks in both 1974 and 1975. Seasonal spider guild trends reflected the temporal prominence of a member species or genus. These temporally abundant species appeared to …

Analysis Of Ecosystem Models, Walter Dewey Valentine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent attempts to apply frequency response analysis to compartmental models of ecosystems are flawed by the failure to define terms in an unambiguous and ecologically meaningful way, and by the failure to distinguish between information feedback and closed material loops. Analysis of the sensitivity of linear models to changes in the A matrix has shortcomings too: elements of the A matrix are often derived from more fundamental parameters and thus do not have a direct relationship to the parent model; only sensitivities to the fundamental parameters will be unconfounded and readily interpretable. A more serious problem with these techniques is …

Comparison Of Microbial Activity In Desert Soils Of The Western United States, Patricia Ann Trujillo Y Fulgham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soils from four regional deserts, Great Basin, Sonoran, Chihuahuan, and Mojave, were collected at times throughout the year which would best exhibit microbial response to moisture or vegetation. The soils were analyzed for several chemical and physical properties. Biological and biochemical characteristics, namely respiration, dehydrogenase activity, adenosine triphosphate concentration, proteolytic activity, nitrification potential, and microbial numbers, were measured.

The soils exhibited fluctuations in microbial activity as measured by respiration, dehydrogenase activity, adenosine triphosphate concentration, proteolytic activity, and nitrification potential during different moisture seasons.

Increase in soil moisture as modified by precipitation did not cause a significant difference in respiration or …

Conflict In Outdoor Recreation, Gerald R. Jacob

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The causes of conflict among users of outdoor recreation resources have received little attention from recreation researchers. Knowledge of factors responsible for conflict might assist recreation planners' attempts to reduce future instances of conflict and help management focus its conflict resolution efforts. A theory of conflict is offered as the first step in systematically procuring such knowledge. A definition and characteristics of outdoor recreation conflicts are presented; four comprehensive causes of user conflicts are proposed. Ten propositions are used to link these factors to conflict and suggest future research hypotheses. The social psychological dynamics of conflict, as described here, have …

Adaptive Significance Of Lactate Dehydrogenase B2 Isozymes In Rainbow Trout, Salmo Gairdneri And A Biochemical Genetic Comparison Of Cutthroat Trout (Salmo Clarki) Populations, Gerald Thomas Klar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rainbow trout lactate dehydrogenase (LDH) B²' B²' , B²' B²" and B²" B²" phenotypes were tested under a variety of conditions for swimming endurance, oxygen consumption rates, and blood pH, pO₂, and lactate. The B²" B²" phenotype exhibited a lower swimming endurance, under a limited oxygen supply, than the B²' B²' and B²' B²" phenotypes. Blood pH at fatigue did not differ among the LOH phenotypes that swam under low oxygen conditions (2 mg/1). …

Population Dynamics And Net Production Of Brown Trout (Salmo Trutta) In Two Areas Of A High Gradient Mountain Stream, Jeffrey C. Gosse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimates of the brown trout (Salmo trutta) population were made in two areas of the Blacksmith Fork River, Cache County, Utah, from June 1972 to June 1973. Additional data were obtained on movement, growth, mortality, biomass, production, and yield.

Population density was highly variable in the area where habitat alterations had occurred, but was relatively uniform where the habitat was undisturbed. The brown trout exhibited little movement except during spawning season. Instantaneous growth and mortality rates are provided for each age group.

Mean annual biomass in the two areas was 12.0 and 10.2 grams per square meter and …