Life Sciences Commons^™

The Effect Of Architectural Variation In Habitat On A Spider Community: An Experimental Field Study -- With Special Reference To Resource Partitioning, James Vincent Robinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider community acceptance of, and segregation by, architectural configuration was investigated for the spiders of Green Canyon in northern Utah. Modular habitat units consisting of 30.48 centimeter (1 foot) cubes of chicken wire supporting internal strands of macrame jute tied in different orthogonal configurations were used. Configurations including all three axes were tested at two strand densities.

The primary null hypothesis tested, that spider species use structures independent of architecture, was rejected in favor of the alternate hypothesis that spider species differentially use structures dependent upon architecture. Of the eight most abundant species, two showed preferences for horizontal substrata and …

Feeding Habits And Reproduction Of Three Sympatric Lizard Species From West-Central Utah, John B. Andre

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The feeding habits and reproduction of Uta stansburiana, Crotaphytus collaris and Cnemidophorus tigris during spring and summer 1976 are described. Feeding habits are expressed in percent total number and volume of prey items and frequency of occurrence of each prey category. Importance Values are also calculated. These values better illustrate the feeding habits of the lizard species than either percent total number and volume and frequency of prey category occurrence.

Lizards consume a variety of food items throughout the growing season. Hymenoptera, Coleoptera, Orthoptera and Arachnida are the major prey categories of U. stansburiana. The major prey categories …

A Study Of Sedge-Dominated Areas In The Uinta Mountains, George Murchie Briggs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Twenty-six sedge-dominated sites in the Uinta Mountains of northeastern Utah were studied. These sites could be placed into two categories, wetland sites (those with water-saturated soils) and alpine tundra sites.

The alpine sites had above-ground standing crops between 37 and 206 g/m². The soils were sandy and low in nutrients. Indirect gradient analysis of the alpine sites showed a relationship between soil stability and vegetation. No other factors were found to be related to overall vegetation patterns.

The wetland sites were dominated by different Carex species than the alpine sites. These wetlands were often patches of monotypic stands. …

The Combined Effects Of Air Temperature, Wind, And Radiation On The Resting Metabolism Of Avian Raptors, Steven R. Hayes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

American kestrels, Falco sparverius; red-tailed hawks, Buteo jamaicensis; and golden eagles, Aguila chrysaetos, were perched in a wind tunnel and subjected to various combinations of air temperature, wind, and radiation. Oxygen consumption was measured under the various combinations of environmental variables, and multiple regression equations were developed to predict resting metabolism as a function of body mass, air temperature, wind speed, and radiation load. Heat transfer analysis of the bird-thermal environment relationship was conducted to produce a biophysical model describing resting metabolism as a function of feather thermal conductance.

Because of differences in surface area to mass …

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 …

The Effect Of Various Environmental Factors On The Growth Of A Red Pigmented Dunaliella Species From The Great Salt Lake, Sam Oeun May

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A red, obligately halophilic Dunaliella species believed to be D. salina was isolated from the North Arm of the Great Salt Lake, Utah, and its optimum growth conditions were determined.

The red pigmented Dunaliella species required an optimum NaCl concentration of 10%, temperature 28°C, and an illuminance of 7500 lux. Ammonium carbonate was preferred over potassium nitrate and ammonium chloride. Potassium nitrate was preferred over ammonium chloride. The average division (generation) time under the above conditions was 46.5 hours.

The alga grown in ammonium carbonate showed a lower content of chlorophyll a compared to those grown in potassium nitrate and …