Life Sciences Commons^™

Alpine Vegetation Of Steens Mountain, Paul Collins

Dissertations and Theses

A determination was made that the summit of Steens Mountain is an alpine tundra. The assessment was based on floristics, vegetation and community structure, environmental parameters, and geomorphological criteria. Microhabitats of Oxyria digyna at low elevations were found to approximate alpine conditions.

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 …

Leaf Development Of Rumex Patientia L. Exposed To Uv Irradiation (280-320 Nm), Judith G. Dickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two factors which affect leaf ontogeny and ultimate leaf size: (1) the rate and duration of cell expansion, and (2) the rate and duration of cell division, were examined for their role in the slowed early growth rate and smaller ultimate leaf size when plants are exposed to ultraviolet-B (UV-B) radiation. Rumex patientia L. was grown in controlled environment chambers under enhanced UV-B radiation (equivalent to daily solar UV-B irradiation at 40°N latitude in mid-May with an atmospheric ozone concentration of 0.20 atm-cm) and control treatments. The pattern of growth as expressed in changes of mean cell size of two …

The Development Of A Curriculum Guide For The Teaching Of Photoreactions On Plant Growth Under Artificial Light, Martha Norris

Morehead State Theses and Dissertations

An applied project submitted in partial fulfillment of the requirements for the degree of Education Specialist at Morehead State University by Martha Norris on March 28, 1978.

The Columnar Junipers Of Western North Dakota (An Investigation Into The Cause Of Their Columnarity), James M. Murphy

Electronic Theses and Dissertations

The objective of this report is to focus on the evaluation of the presence and amount of ethylene in the burning lignite fumes and to search for morphogenetic factors in the lignite at the Slope County site. The former was considered to be more important and was investigated more thoroughly.

Methods Of Analysis Of Yield From Antecedent Winter Water, Charles Gregg Carlson

Electronic Theses and Dissertations

This investigation is an evaluation of methods of analysis of water conserved during off-season periods and evaluation of the effect on the subsequent crop. Energy and water shortages during the midsummer peak irrigation season have forced farmers to consider the possibility of irrigation at times other than peak growth stages as an alternative practice. Dryland farmers are interested in the benefit of water conserving cultural practices such as summer fallow and snow trapping. To evaluate the benefit of these off-season practices, a yield function based upon water availability is necessary. In order to better understand the effects of off-season irrigation …

Plant Availability Of Aqueous Phosphates Removed By Fly Ash, Paul D. Weeldreyer

Electronic Theses and Dissertations

Recycling non-renewable resources has become increasingly. important as man has continuously expected more and more from his environment. As stated by Spendlove (1976): "Recycling certainly is not new. It appears, in fact, to be one of the most obvious laws of nature, much like the seasons, the tides, and the life and death processes. It is not surprising, therefore, that the greatest motivating force behind present recycling efforts is the worldwide concern for the deteriorating natural environment." This ever-increasing demand for more production has created the need for more stringent pollution controls to maintain an acceptable quality of life. Pollution …

The Transfer Of Resistance To Wheat Streak Mosaic Virus (Wsmv) From Wheatgrass (Agropyron Intermedium (Host.) Beauv.) To Common Wheat (Triticum Aestivum L. Em. Thell.) By Irradiation, Harnek S. Sandhu

Electronic Theses and Dissertations

A virus disease, wheat streak mosaic, has been an important, unsolved problem of winter wheat which is a major crop in South Dakota. F₁BC₃ monosomic alien addition seeds having three doses of Centurk were irradiated with fast neutrons to translocate a segment of the alien chromosome accounting for immunity from wheat streak mosaic virus to a Centurk chromosome. Immune plants from the irradiated seeds were used as male parents onto Centurk and about 2,000 F₁BC₄ seeds obtained. Cytological examination of pollen mother cells of 151 resistant F₁BC₄ plants indicated that the …

In Vitro Propagation And Tissue Culture Of Selected Monocots, Reid Harvey Graves

Dissertations, Theses, and Masters Projects

No abstract provided.

A Comparative Scanning Electron Microscope Study Of Leaf Surface Morphology And Anatomy For Four Species Of Abronia Found Within California, Elliott Helm

Theses Digitization Project

No abstract provided.

Water And Nitrogen Husbandry For Irrigated Corn In Central South Dakota, Stanley Eugene Papendick

Electronic Theses and Dissertations

The purpose of this study was to evaluate the effects of supplemental water and nitrogen on corn yields. Central South Dakota was chosen as the location for this study because of its existing irrigation and the limited research data available from that part of the state. The objectives were: (1) to determine corn yield response to various water regimes, (2) to determine corn yield response to nitrogen applications, and (3) to determine corn yield response to nitrogen application methods.

The Effect Of Foliar Fertilization On Soybean Yield And Leaf Necrosis, Robert Jay Goos

Electronic Theses and Dissertations

The soybean (Glycine max (L.) Merrill) is a very important world crop. The seed is rich in both protein and oil, making it a valuable human food resource. Many scientists believe that there are physiological barriers preventing increased soybean yields. Any agronomic discovery that would consistently increase soybean yields would be important to world food production. One possible yield barrier in soybeans concerns the mineral nutrition of the plant during the seed-filling stages of growth. During this period of growth, translocation of N, P, K, and S from the plant foliage to the developing seed occurs, accompanied by a virtual …

Antimicrobial Activity Of Plant Extracts, Melinda J. Seid

University of the Pacific Theses and Dissertations

The purpose of this study was to investigate a possible antimicrobial activity in the following plants: Brunfelsia hopeana, Anemopsis californica, and Heimia salicifolia against Staphylococcus aureus, a Gram-positive coccus, Escherichia coli, a Gram-negative fermenter, Pseudomonas aeruginosa, a Gram-negative non-fermenter, and the yeast Candida albicans.

Small Mammal Dissemination Of Dwarf Mistletoe Seeds, Daniel Eugene Lemons

Dissertations and Theses

No study has been done in the western United States concerning dispersal of dwarf mistletoe by mammals. At the outset of the study it was determined that the red squirrel, the yellow pine chipmunk (Eutamias amoenus), the northern flying squirrel, and the bushy-tailed wood rat (Neotaoma cinerea), were all potential vectors of seeds. The red squirrel was chosen as the main object of study because it is diurnal and is closely associated with ponderosa pine (Pinus ponderosa), a heavily infected species. The study was undertaken to determine whether small mammals play a significant role in transporting mistletoe seeds to uninfected …

The Ultrastructure Of Cell Division In Male Reproductive Branches Of Polysiphonia Denudata, Cynthia Louise Bosco

Dissertations, Theses, and Masters Projects

No abstract provided.

Investigations Of Possible Allelopathic Effects Of Lycopodium Flabelliforme (Fern.) Blanch., Joan Macuszek

Masters Theses

Lycopodium flabelliforme (Fern.) Blanch. sporophytes were collected from a colony west of Flat Rock in Crawford County, Illinois. The material was either ground to a coarse grade using a Wiley Mill (grindate), left whole and untreated (fresh) or water extracted with a Waring blender (extract). The effect of the sporophyte material was tested on the germination of seeds and on the growth of seedlings of Raphnus sativa L. Sporophytes subjected to the grindate treatment showed the most inhibitory effects. It was shown that the alledged inhibitory substance was heat stable and able to be concentrated. Using column chromatography, at 37.7°C, …

The Effects Of Sulphur Dioxide On Selected Hepatics, Steven L. Gatchel

Masters Theses

Extensive studies have been reported on the air pollutant sulphur dioxide (SO₂), and its effects on vascular and nonvascular plants. It has been shown to interrupt normal physiology, metabolism, reproduction, and alter the plant’s morphology.

Of the cryptogams, lichens have been extensively used as biological indicators of air pollution. More recently, bryophytes have been shown to be as sensitive to contaminates as lichens, and may exhibit responses to the pollutant similar to those of vascular and nonvascular plants. The threshold sensitivity of these cryptogams is about 0.5 ppm over a 12 hour period. However no study to date …

Germination, Respiration And Photosynthesis In Seeds Of Dwarf Mistletoe (Arceuthobium), Steven Wayne Gustafson

Dissertations and Theses

Germination, respiration, and photosynthesis in seeds of dwarf mistletoe (Arcenthobium) were studied. The effects of 1 hour soakings of seeds in aqueous solutions of 1, 2, or 3% H₂O₂ or 1, 2, 3, 4, or 5% Chlorox on germination of seeds were tested. Germination rates for seeds from three consecutive years (1975-1977) were obtained. Germination rates varied widely. This variance transcended subtle changes in treatment. Pretreatment of seeds with Chlorox resulted in significantly lower germination rates than those of the control. Chlorophyll concentrations were determined for seeds and aerial shoot tissue of four species. Seeds of A. …

The Cirsium Altissimum - Discolor Complex In Illinois, Dennis R. Bischoff

Masters Theses

Cirsium altissimum, C. discolor and suspected hybrids used in this study were collected during September 1977 from three locations in east central Illinois. All were combined for subsequent taking of data because the study dealt with incidence of hybridization and morphological discriminators rather than degrees and directions of introgression. Ten possible discriminators were chosen by examination of herbarium specimens of parental plants: I, Involucre width; II, Involucre height; III, Pubescence of upper leaf surface; IV, Angle of departure of main veins from the midrib; V, Number of spines per cm along the margin; VI, Length of indurate portion of …