Life Sciences Commons^™

The Population Biology And Demography Of Cimicifuga Rubifolia Kearney And The Genetic Relationships Among North American Cimicifuga Species, Rebecca Ann Cook

Doctoral Dissertations

In this beginning study of the population biology of Cimicifuga species, the life history and demography of the long-lived herbaceous perennial, Cimicifuga rubifolia Kearney, were investigated, the genetic structure of some of its populations was studied, and an investigation of the genetic relationships among the North American species was begun.

The life history and demography were monitored in two populations, one of approximately 1400 individuals (1987-1990) and the second of about 400 individuals (1988-1990). A model of leaf area was used to determine the leaf area (photosynthetic size) of individuals and this was followed during the study. Relationships between the …

Effects Of Elevated Co2 On Crop Growth Rates, Radiation Absorption, Canopy Quantum Yield, Canopy Carbon Use Efficiency, And Root Respiration Of Wheat, Oscar A. Monje

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wheat canopies were grown at either 330 or 1200 μmol mol^-1 CO₂ in sealed controlled environments, where carbon fluxes and radiation interception were continuously and nondestructively measured during their life cycles. The effects of elevated CO₂ on daily growth rates, canopy quantum yield, canopy and root carbon use efficiencies, and final dry mass were calculated from carbon flux measurements in an open gas exchange system. Dry biomass at harvest was predicted from the gas exchange data to within ± 8%. The greatest effect of elevated CO₂ occurred in the first 15d after emergence; however, several physiological …

Effect Of Salinity (Nacl) On Germination, Growth, Ion Accumulation, And Protein Synthesis In Alfalfa (Medicago Sativa L.), Thamir S. Al-Niemi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To study the effect of NaCl stress on gene expression in alfalfa (Medicago sativa L.), greenhouse and laboratory experiments were conducted with 22 cultivars during germination and post-germination growth. The ability of alfalfa cultivars to germinate at the different NaCl concentrations was not related to their postgermination performance (salt tolerance) under those conditions.

Genetic effects were evident for Na and Cl ion uptake and accumulation in alfalfa shoots and roots. The strategies of alfalfa cultivars to cope with NaCl stress includes exclusion of Na from shoots and Cl from roots or from the whole plant depending on cultivar and …

Influence Of Microphytic Crusts On Selected Soil Physical And Hydrologic Properties In The Hartnet Draw, Capitol Reef National Park, Utah., John Dana Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microphytic crust influences on selected physical and hydrologic soil properties were examined at one location in Capitol Reef National Park, Utah. Designed experiments were conducted in a sandy loam soil where microphytic crusts were present without the concomitant development of confounding physical or chemical soil conditions. Three treatments were used for all experiments: control, chemically killed (microphytes killed but left in place), and scalped (microphytic crusts mechanically removed).

A portable wind tunnel was used to deter-nine if microphytic crusts contribute to soil stability and reduce the erosive effect of wind. Significantly lower threshold friction velocity and greater wind-entrained material were …

Competitive Interaction Between Crested Wheatgrasses And Cheatgrass, Mark G. Francis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current revegetation practices in the lntermountain West include the use of Nordan (Agropyron desertorum) and Hycrest (A. cristatum x desertorum) crested wheatgrass on rangeland susceptible to cheatgrass (Bromus tectorum) invasion, although little quantitative data exists that compares their competitive abilities. We evaluated both the competitive ability of Hycrest and Nordan in two-species mixtures with cheatgrass, and evaluated seedling establishment characteristics for all three species in a greenhouse study. Linear and nonlinear models were developed for a range of densities for each species to predict median above-ground biomass and tiller numbers. In both experiments, increasing …

Effects Of Water Stress Preconditioning On Plant Water Relations And Transplant Survival Of Artemisia Cana And Agropyron Intermedium, Jerriann Ernstsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Typically, dormant seedlings are transplanted when revegetating nonirrigated disturbed lands in order to prevent transplant shock triggered by water stress. Since dormant seedlings have to be used, this limits the duration of the transplant season. It may be possible to increase this limited season by inducing acclimation responses that would increase drought tolerance. Preconditioning actively growing seedlings to water stress prior to transplanting could induce acclimation responses such as solute accumulation and/or stomatal modulation.

Under greenhouse conditions, A. cana and A. intermedium seedlings were subjected to three water stress preconditioning treatments: a well watered control, one dry-down cycle, and three …

Population Dynamics In Response To Fire In Quercus Laevis - Pinus Palustris Barrens And Related Communities In Southeast Virginia, Allen E. Plocher

Biological Sciences Theses & Dissertations

Permanent plots in the Zuni Pine Barrens (Isle of Wight Co., Virginia) were sampled in order to: quantify plant population dynamics in response to fire, compare these dynamics among different moisture regimes, compare the effect of mechanical understory removal to that of fire on tree seedling and herbaceous dynamics, and determine the effect of dense lichen (Cladonia spp.) coverage on pine seedling establishment and survival. Fire resulted in 40% aboveground mortality in the overstory, 80% in the sapling/large shrub layer, and nearly 100% in the understory, followed by a 3.3 to 10.6 fold increase in understory density. Regeneration …

Vascular Flora Of Three Watersheds In The Fernow Experimental Forest And Factors Influencing Species Composition Of The Herbaceous Layer, Staci Dudash Smith Aulick

Theses, Dissertations and Capstones

Herbaceous layer communities respond to a number of environmental variables in forests: thus, study of the herb layer is essential for a more complete understanding of the forest ecosystem. The objectives of this study were to (1) describe the flora of the watersheds. (2) describe the species richness and diversity of watersheds 3, 4 , and 7 of the Fernow Experimental Forest, Parsons, West Virginia, and (3) examine stand and soil variables and their influence on the herbaceous communities or the forest. Watersheds were selected on the basis of stand age/history (WS3 "20yr, clearcut; WS7 "20 yr. clearcut and herbicide: …

Growth Response Of Eelgrass (Zostera Marina L) To Root-Rhizome And Whole Plant Exposure To Atrazine, Arthur C. Schwarzschild

Dissertations, Theses, and Masters Projects

No abstract provided.

Lichen Communities On White Oaks In East-Central Illinois, Michael R. Thon

Masters Theses

This study was conducted as a survey of epiphytic lichen communities occurring on white oak trees at Walnut Point State Park (Douglas Co.) and Fox Ridge State Park (Coles Co.). Using a system of cover classes to estimate lichen cover, quantitative data on the distribution and abundance of epiphytic lichens was obtained. These data were used to calculate summary statistics of each community including total cover, species richness, and Shannon diversity. A total of ten taxa representing six genera were found. The foliose lichen Physcia millegrana had the highest cover in the open canopy habitats while all other taxa had …

The Effects Of Turf Compression On Plants Growth Regulator Efficacy, William Lyle Petersen

Masters Theses

A 150kg lawn roller was used in combination with various Plant Growth Regulators (PGR) (Embark & Event, Event & Oust, Embark & Oust, Escort & Oust, Telar & Oust, Event & Balan, Oust & Balan, and Balan) to evaluate its affects on the growth rate of rough turf at the Coles County Airport. The rolled plots were evaluated for height, reduction of seedheads, phytotoxicity, and weed control. Rolling was of no significance to treated or untreated turf. PGR combinations containing Oust were significantly better at reducing turf height than combinations lacking Oust. PGR combinations lacking Oust discolored turf significantly less …

The Use Of Tissue Culture For The Improvement Of Salt Tolerance In Atriplex Spp, Danielle L. Eyre

Theses : Honours

Soil salinity is widespread throughout the world, and human activity is responsible for increases in the area of land affected by salt. Replanting saline areas using salt-tolerant, or halophytic, species is one method of reclaiming this land. This project investigated the possibility of using in vitro methods to select for increased salt tolerance in halophytic plants. By establishing clonal lines of halophytes in culture and screening those clones for cells exhibiting variation in their capacity to tolerate salt, it may be possible to regenerate plants with elevated salt tolerance. Clonal lines of six species of A triplex (saltbushes) were obtained. …

Breeding Systems In Spiranthes Magnicamporum Sheviak, Christopher D. Loyet

Masters Theses

A study of the ecology, breeding systems, and pollinators of Spiranthes magnicamporum Sheviak was undertaken in fall 1992. An initial survey of three glacial drift hill prairies revealed sexual activity in this species via removed pollinia. Two hill prairie populations were used for pollination study. In each population, five individuals were randomly selected and crossed using autogamic, geitonogamic, and xenogamic methods. In addition, ten individuals were fitted with pollinator-exclusion bags. After capsule formation, all plants were harvested. They were examined in the lab for general morphology, the presence or absence of embryo formation, and the prescence of sexual or asexual …

Corticolous Bryophytes Of East-Central Illinois, R. Korkut Canayakin

Masters Theses

Among the numerous factors that influence epiphytic corticolous bryophytes, inclination, "raintracks", aspect, and phorophyte seem to play important role.

In order to determine the effects of these factors, 203 forest trees located in five sites has been examined. The results were arranged in tables and charted.

Vegetation And Tree Survival In A Savanna Restoration Project, Vermilion County, Illinois, Mary Claire Hruska

Masters Theses

This study involved pre-burn and post-burn inventories of herbaceous and woody vegetation, a post-burn tree survival survey, the development and implementation of a management plan for the savanna restoration site and the development of general guidelines for savanna restoration. An herbarium collection was made, 242 species representing 64 families were found on the site.

There were several significant changes in the density and frequency of vegetation after the burn. The following herbaceous species increased significantly in frequency: Agalinis tenuifolia (Vahl.) Raf, Ambrosia artemisiifolia L., Carex spp., Cassia fasciculata Michx., Desmodium glabellum (Michx.) DC., Dichanthelium acuminatum (Sw.) Gould & Clark var. …