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Factors Influencing Epiphytic Lichen Communities In Aspen-Associated Forests Of The Bear River Range, Idaho And Utah, Paul C. Rogers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing habitat, thereby threatening their long-term local and regional viability. Though lichens have a rich history as air pollution indicators, I believe that they may also be useful as a metric of community diversity associated with habitat change. To date, few studies have specifically examined the status of aspen's epiphytic lichen …

The Spatial Distribution Of The Nests Of The Black-Crowned Night Heron (Nycticorax Nycticorax) And The Snowy Egret (Leucophoyx Thula) In Central Utah, Randall S. Isham

Theses and Dissertations

Nests of the Black-crowned Night Heron and the Snowy Egret were examined in five central Utah colonies in 1973 to determine the spatial distribution within the colony. Nest locations of the 1085 nests of the two species were plotted to the nearest foot with an alidade and plane table. Tests of randomness, clump size, association, segregation, and T distribution were utilized. No differences between species were noted for the distance to the nearest and the next nearest nest. The Night Heron nested closer to other Night Herons and more often than did the Snowy Egret which non-significantly selected either species …

Comparisons Of Phytoseiid Predator Populations In Sprayed And Unsprayed Apple Orchards In Cache Valley, Utah, Yeboa A. Dodoo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A comparative study of phytoseiid populations was made of two well-cultivated and regularly sprayed apple orchards with two unsprayed orchards in Cache Valley, northern Utah.

Two phytoseiid species, Typhlodromus mcgregori Chant and T. occidentalis Nesbitt were observed on the apple leaves, under the bark, and occasionally in the litter and soil. Amblyseius cucumeris (Oudemans) occurred in the soil and litter and occasionally under bark. T. mcgregori was dominant in the unsprayed orchards, and T. occidentalis in the sprayed.

Of the phytophagous mites, which served as food for the phytoseiids, the two-spotted mite, Tetranychus urticae Koch was dominant. Other phytophagous mites …

Mammals Of The Lynndyl, Utah, Sand Dune Area : A Population Problem, Hugh J. Phillips

Theses and Dissertations

The purpose of this study was to determine the kinds, population, distribution, and general habits of the mammals of the Lynndyl sand dune area. Only one article concerning the dunes was found, but several have been written on other dunes; however, none was found concerning mammals. Two quantitative studies, plot and transect trappings, were made and general observations were taken within the study area. Three types of plots; Russian thistle, juniper, and baren moving dunes; were trapped and revealed the following species: Dipodomys ordii, Peromyscus maniculatus, Reithrodontomys megalotis, Onychomys leucogaster, and Neotoma lepida. The most numerous animal in all plots …

Ecology Of Passerine Birds Wintering At Utah Lake, Joseph R. Murphy

Theses and Dissertations

During the period of October to April of the winter of 1950-51, an ecological study was undertaken of a population or passerine birds wintering in a segment of the Utah Lake Shore. Available winter weather data indicated that although such factors as precipitation, temperature, and wind may often be severe, they are not critical enough to prevent a fairly large population of passerine birds from spending the winter months in the study locale. Five fairly distinct plant communities can be recognized in the area. There is evidence which indicates that certain passerine bird species are especially dependent on a particular …