Physical Sciences and Mathematics Commons^™

Identities And Motives Of Naturalist Development Program Attendees And Their Relation To Professional Careers, Jennifer A. Mraz

Dissertations

In recent years, there has been much concern over the decline of biologists who actually identify themselves to be naturalists, which negatively impacts the field of conservation and the study of biology as a whole. This could result in a decrease in individuals who participate in naturalist-like activities, such as informal environmental education and environmental volunteerism. The purpose of my study was to determine what discourse identities were held by naturalist development program participants, how these discourse identities related to their volunteer motives in environmental settings, and how discourse identity related to professional careers. I defined identity through the lens …

Human Impacts On Fire In De Soto National Forest, Mississippi, U.S.A., Charles Raymond White

Master's Theses

Fire is a common occurrence in the longleaf pine (Pinus palustris) forests of the Southeast United States. Prescribed fire is used to manage these threatened ecosystems, but information regarding historical fire activity is unknown. My goals were to determine the historical fire regimes in De Soto National Forest (DSNF), southern Mississippi, and determine the influence of climate and land use history on fire activity at two study sites: Fern Gulley Ridge (FGR) and Death Scar Valley (DSV). The composite mean fire interval during the prescribed burning period (1980–2013) was 3.4 years. During settlements periods, fire intervals at FGR …

Biogeochemical Alteration Of Particulate Pyrogenic Organic Carbon (Pyc), Jason Matthew Stuart

Master's Theses

The resistance of plant derived pyrogenic organic carbon (pyC) to abiotic and biotic means of degradation has led to increased interest in the role of pyC as a potential carbon sink, as well as a strategy for sequestering atmospheric CO2 to mitigate excess carbon emissions. Though much research pertaining to the fundamental properties of pyC degradation have been performed in a controlled lab setting, there has been very little work regarding pyC degradation in a field setting where factors such as precipitation and temperature fluctuate seasonally. This work focuses on various degradation characteristics of two …

Application Of A New Tree-Ring Based Drought Reconstruction Method At Multiple Forest Sites Across Indiana, U.S.A., Kayla Mechelle Pendergrass

Master's Theses

This thesis research used techniques of dendrochronology to investigate the efficacy of using multiple co-occurring species (MCOS) in a climate reconstruction model compared to a single species (SS) in four old-growth forests in Indiana: Pioneer Mothers Memorial Forest (PM), Donaldson Woods (DW), Hoot Woods (HW), and Lilly Dickey Woods (LD). The objectives of this study were to [1] evaluate the climate response of all chronologies (n = 19; 7 species) to determine the most appropriate climate variable for reconstruction and [2] determine if the MCOS model outperforms the SS model at each individual study site. Model comparison was conducted …

A Comparison Of Habitat And Geomorphic Changes On East Ship Versus Sand Islands Mississippi, 2007-2014, Carlton Peter Anderson

Master's Theses

ABSTRACT

A COMPARISON OF HABITAT AND GEOMORPHIC CHANGES ON EAST SHIP VERSUS SAND ISLANDS MISSISSIPPI, 2007-2014

by Carlton Peter Anderson

May 2015

The islands of the Mississippi-Alabama (MS-AL) barrier island chain along the micro-tidal northern Gulf of Mexico are highly dynamic coastal features subject to rapid changes in habitat, geomorphology, and elevation by natural and anthropogenic disturbances, such as hurricanes, subsidence, sea-level rise, and dredging activities. The purpose of this study was to compare elevation, total volume, habitat-type coverage, and short-term change between “naturally” formed East Ship Island and “man-made” Sand Island (Disposal-Area 10). This study used a combination of …

A Study On Photodegradation And The Fate Of Pyrogenic Carbon, John Thomas Howell

Master's Theses

Accounting for all possible sources of atmospheric CO₂ is a pressing issue today due to the increasing effects of climate change. Estimates suggested that on the order of 1.3 million tons of dissolved pyrogenic carbon (pyDOC) could be entering the northern Gulf of Mexico annually. Assessing the fate of pyDOC in aquatic systems is crucial to understanding ecosystem impacts and potential feedback to climate change. Current research indicates that despite a generally lower susceptibility to biodegradation than their unpyrolyzed equivalents, pyrogenic carbon is not environmentally inert. While the role of microorganisms on the fate and transformation …