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Waterfowl Ecology And Utilization Of Uinta Mountain Water Areas, Steven Roger Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Waterfowl utilization was recorded by observing study units at different elevations from the time water areas were thawed in the spring until they were frozen in the fall.

Sixteen species of waterfowl were observed in the Uinta Mountain; mallards, green-winged teal, pintails, and ring-necked ducks were breeders.

Ninety-eight percent of all waterfowl observed were below 10,000 feet.

Waterfowl numbers were highest during migratory periods and lowest in the breeding season.

Adult waterfowl were observed most often on natural water areas and beaver ponds greater than one acre.

Water areas at lower elevations had high indices of aquatic invertebrates and contained …

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 …

An Experimental Study Of Variation Within And Between Populations Of Petrophytum Caespitosum (Nutt.) Rydb. With Emphasis On Numerical Techniques, Frank R. Drysdale

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nine populations of sixty-eight individuals representing the distribution of Petrophytum caespitosum (Nutt.) Rydb. (Rosaceae) in the Intermountain Region were investigated for taxonomically significant variation using numerical techniques. On the basis of 19 morphological characters 3 subspecific taxa are recognized. Two taxa are existing subspecies: P. caespitosum (Nutt.) Rydb. var. caespitosum and P. caespitosum (Nutt.) Rydb. var. elatius (S. Wats.) Tides. One new subspecies is described: P. caespitosum (Nutt.) Rydb. var. latifolium. The ecology of the species is discussed. The floral and vegetative anatomy are described. Chromosome counts of 3 populations have given n = 9. A list of herbarium …