Physical Sciences and Mathematics Commons^™

Mat Movement In Coastal Louisiana Marshes: Effect Of Salinity And Inundation On Vegetation And Nutrient Levels, Christopher Martin Swarzenski

Biological Sciences Theses & Dissertations

The present research compared and contrasted the physical structure of floating and rooted marshes, their differing responses to open-water salinities and inundation, as well as the nutrient distribution in the porewaters and sediment. The effects of the physical differences in the two marsh types on the ocurrence of the dominant emergent vegetation was discussed.

The main difference in physical structure of the two marsh types was the presence of a mineral, non-buoyant layer at 25-45 cm depth in the rooted marsh, which could serve as an anchor for the overlying highly organic mat layer found in both marsh types. Porewater …

Dynamic Multi-Species Animal Habitat Modeling With Forest Succession Models, Stephen A. Compton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research determines and demonstrates the ability to simulate dynamic multi-species animal habitat suitability with forest succession models. A literature review of dynamic animal habitat models is presented. The structure of an existing forest simulation model (MASS10) was modified from a basal area-based model to a volume-based model (DYNAM10). The forest model was calibrated using data from permanent-plot growth and vegetation samples collected by USDA Forest Service Forest Survey procedures. The theoretical growth parameters used to simulate stand development were validated. Predictions of DBH and height growth, as well as stand-level behavior, were verified. A subroutine, VEGDYN, was added to …

Effects Of Polyacrylamide On Rangeland Soils And Plants, Saud Leily R. Al-Rowaily

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives of this study were to determine the effects of two forms of polyacrylamide (PAM) conditioners (Cross-linked and Non-cross-linked PAM) on evaporation, saturated hydraulic conductivity, water retention, crust and crack formation of soils, seed germination, and seedling and tubeling growth.

The two PAM conditioners, 0.2% concentration by weight, were mixed with seven soils of different textures (sandy loam, silt, silty clay loam, silt loam, fine sand, medium sand, and coarse sand) to investigate the effects on evaporation, saturated hydraulic conductivity, and water retention. Soil samples of different textures were brought to field capacity and placed in a growth chamber …

Factors Affecting The Kinetics Of Light Intensity Adaptation In Marine Phytoplankton, Chunzhi Guo

OES Theses and Dissertations

It has been suggested that the recent light history of phytoplankton and the kinetics of photoadaptation can be used to provide information about the vertical mixing processes in the upper mixed layer. To be useful as a parameter in a model of photoadaptation and vertical mixing, the response of a photoadaptive variable to changes in growth irradiance must be monotonic, significant, and comparable in time rate scale to mixing processes. Previous studies of photoadaptation kinetics have focused on the response of phytoplankton to changes in light intensity under continuous illumination. This dissertation attempts to elucidate the effects of light:dark cycle, …

Survival Of Juvenile Queen Conch, Strombus Gigas, In Natural Habitats: Impact Of Prey, Predator And Habitat Features, Livingston Sinclair Marshall Jr

Dissertations, Theses, and Masters Projects

In this dissertation, I experimentally examine predation-induced mortality upon juvenile queen conch, Strombus gigas, and assess the importance of select habitat predator and conch characteristics affecting predation intensity. Experiments were conducted during the summer and early fall of 1987, 1988, 1990 and 1991 in seagrass beds and adjacent sand flats near Lee Stocking Island, Exuma Cays, Bahamas. These experiments indicate that various factors act interactively to produce habitat-specific mortality rates in queen conch due to predation. These include (1) habitat type, whereby seagrass beds offer some protection; (2) local population dynamics, such that populated seagrass beds appear to enhance conch …

Shoreline Habitat Selection By Bald Eagles (Haliaeetus Leucocephalus) In A Non-Breeding Eagle Concentration-Area On The James River, Virginia, Kennedy H. Clark

Dissertations, Theses, and Masters Projects

No abstract provided.

Distribution, Abundance, And Behavior Of The Cownose Ray, Rhinoptera Bonasus (Mitchill 1815), In Lower Chesapeake Bay, Robert A. Blaylock

Dissertations, Theses, and Masters Projects

Aspects of the ecology of the cownose ray, Rhinoptera bonasus, in the lower Chesapeake Bay and its tributaries were studied using aerial surveys, biotelemetry, and examination of stomach contents. The Chesapeake Bay was surveyed by airplane during 1986-1989, to examine the distribution of cownose rays and estimate their abundance using line transect methods. Cownose rays resided in Chesapeake Bay throughout the summer months, entering in early June and emigrating in late September. They were usually absent, or nearly so, by late October. Mean monthly abundance ranged from none present in May and November, to a September average of 9.3 &\cdot& …

The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin

Masters Theses

Dam construction by beavers creates wetlands which have the potential to improve water quality, especially in areas near urban centers. However, beaver dams may also cause flooding problems which can result in the removal of the beaver(s) and the destruction of their dam. A further understanding of how beaver-created wetlands affect water quality will provide additional data which can be utilized in beaver management decisions.

In this study, 41 chemical parameters were examined from water taken above and below beaver-created wetlands that existed in DuPage County, Illinois between May and September 1991. This study was designed to examine the effects …

Modelling Of Zinc Accumulation In The American Oyster, Crassostrea Virginica (Gmelin), Cheol Mo

Dissertations, Theses, and Masters Projects

A model of zinc accumulation by the American oyster, Crassostrea virginica, is developed by relating in-situ zinc body burden to time-integration of uptake. Short-term uptake rates are estimated in laboratory by introducing &\sp{lcub}65{rcub}&Zn to oysters of various weights in aquaria with salinities of 18&\perthous& and 12&\perthous&. Uptake of &\sp{lcub}65{rcub}&Zn by an oyster: (1) varies as a power function of the body weight (soft tissue dry weight) of the oyster (&dy\over{lcub}dt{rcub}& = kW&\sp{lcub}\beta{rcub}&), (2) is inversely related to the salinity of ambient water, and (3) increases linearly with ambient concentration. Zinc body burdens of oysters of various weights from oyster beds …