Digital Commons Network^™

Presence And Function Of Tetrodotoxin In Terrestrial Vertebrates And Invertebrates, Amber N. Stokes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tetrodotoxin (TTX) is a potent neurotoxin found in a variety of species. This toxin has long been of concern to human health as it is found in puffer fish, which are a delicacy in Japan. Since the distribution of this toxin is so great, there are many questions regarding the evolution and ecology of organisms that have TTX. My research has focused on further investigating three topics with this research: production, predation, and identification of novel TTX bearing taxa. In order to perform this research I first refined a Competitive Inhibition Enzymatic Immunoassay methodology to quantify levels of TTX in …

The Distribution Of Fruit And Seed Toxicity During Development For Eleven Neotropical Trees And Vines, Noelle G. Beckman

Biology Faculty Publications

Secondary compounds in fruit mediate interactions with natural enemies and seed dispersers, influencing plant survival and species distributions. The functions of secondary metabolites in plant defenses have been well-studied in green tissues, but not in reproductive structures of plants. In this study, the distribution of toxicity within plants was quantified and its influence on seed survival was determined in Central Panama. To investigate patterns of allocation to chemical defenses and shifts in allocation with fruit development, I quantified variation in toxicity between immature and mature fruit and between the seed and pericarp for eleven species. Toxicity of seed and pericarp …

Using Qual2kw As A Decision Support Tool: Considerations For Data Collection, Calibration, And Numeric Nutrient Criteria, Andrew J. Hobson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Surface water quality in the United States is managed by the U.S. Environmental Protection Agency (EPA) under direction of the Clean Water Act. Designated uses are required for all state waters. Numeric or narrative water quality standards provide measures to determine if each waterbody meets the intended use. Narrative standards typically include vague terminology that is difficult to interpret and this has led EPA to encourage states to develop numeric criteria for nutrients in all its streams, rivers, and lakes. These numeric nutrient criteria are intended to stave off the harmful effects of over-growth of aquatic plants which can result …

Forest Recovery, Nutrient Cycling And Carbon Sequestration In A Southern Appalachian Spruce-Fir Forest, Patrick T. Moore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Our forests provide us with a variety of services from clean water, forest products and wildlife habitat to the lesser known functions of nutrient cycling and carbon
sequestration. This research helps to demonstrate the extent of some of these services in a heavily disturbed southern Appalachian spruce-fir forest within Great Smoky Mountain National Park, the most heavily visited National Park in the United States. Following a catastrophic infestation of the non-native balsam wooly adelgid, the future of this forest was unknown, causing some to speculate about the future of this sensitive forest type. Though predictions about this forest’s future varied …

A Data-Intensive Assessment Of The Species Abundance Distribution, Elita Baldridge

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One of the most commonly observed patterns in ecology is the fact that at most locations there are a large number of relatively rare species, composed of only a few individuals per species, and a small number of relatively common species. This pattern of commonness and rarity is quantified by the species abundance distribution. As one of the most commonly observed patterns in ecology, it has been studied intensively for over 100 years.

A major emphasis of this research has been developing models to try to understand the forces that generate such a general pattern. As a result, there are …

Integrated Management Of Downy Brome (Bromus Tectorum L.) Infested Rangeland, Heather Elwood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasive weed species are a threat to the health and functionality of many rangeland systems. Downy brome (Bromus tectorum) is an invasive annual grass that affects the productivity of rangelands by decreasing the grazing capacity for livestock as well as altering the wildfire cycle and competing against more desirable vegetation for limited resources.

In 2006, an Invasive Plant Management Plan and Environmental Assessment was approved for Dinosaur National Monument, calling for prioritization of invasive species management on high value wildlife habitat, vector areas, and for species with a high ecological impact. The Cub Creek Watershed was identified as a priority …

An Environmental History Of The Bear River Range, 1860-1910, Bradley Paul Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The study of environmental history suggests that nature and culture change all the time, but that the rate and scale of such change can vary enormously. During the late 19th and early 20th centuries, Anglo settlement in the American West transformed landscapes and ecologies, creating new and complex environmental problems. This transformation was particularly impressive in Cache Valley, Utah's Bear River Range. From 1860 to 1910, Mormon settlers overused or misused the Bear River Range's lumber, grazing forage, wild game, and water resources and introduced invasive plant and animal species throughout the area.

By the turn of the 20th century, …

The Need To Address Black-Backed Jackal And Caracal Predation In South Africa, David L. Bergman, Ho De Waal, Nico L. Avenant, Michael J. Bodenchuk, Michael C. Marlow, Dale L. Nolte

Wildlife Damage Management Conference

Prior to 1990, the four provincial governments of South Africa had a variety of programs in place to manage predation by black-backed jackals and caracals through lethal and nonlethal management in close cooperation with livestock farmers. During the 1990s the official programmes were phased out due to a multitude of factors including lower predation rates. Today, thousands of livestock (primarily sheep and goats, but also cattle and wildlife) are lost each day in South Africa due to black-backed jackal and caracal predation. The actual numbers are not known because not all losses are accounted or reported. It also does not …

Enhancing Theutility Of Visitor Impact Assessment In Parks And Protected Areas: A Combined Social-‐‐ Ecological Approach, A. D'Antonio, Christopher Monz, P. Newman, S. Lawson, D. Taff

Christopher Monz

No abstract provided.

Influence Of Removal Sampling Of Small Mammals On Abundance And Diversity Attributes: Scientific Implications, Thomas P. Sullivan, Druscilla S. Sullivan

Human–Wildlife Interactions

Terrestrial small mammals occupy a variety of temperate and boreal forests in North America and Eurasia and contribute to biodiversity within these ecosystems. Researchers commonly use a variation of removal trapping to sample small-mammal populations and communities in these systems. However, it is not known if recurrent removal sampling might bias abundance estimates or alter the very populations under study. We addressed 2 questions: (1) are estimates of population size and species richness and diversity gained from removal trapping different from those based on live-trapping? and (2) what residual impact does removal trapping have on small-mammal populations and communities, as …

Continental-Scale Assessment Of Genetic Diversity And Population Structure In Quaking Aspen (Populus Tremuloides), Colin M. Callahan, Carol A. Rowe, Ronald J. Ryel, John D. Shaw, Michael D. Madritch, Karen E. Mock

Wildland Resources Faculty Publications

Aim: Quaking aspen (Populus tremuloides) has the largest natural distribution of any tree native to North America. The primary objectives of this study were to characterize range-wide genetic diversity and genetic structuring in quaking aspen, and to assess the influence of glacial history and rear-edge dynamics.

Location: North America.

Methods: Using a sample set representing the full longitudinal and latitudinal extent of the species’ distribution, we examined geographical patterns of genetic diversity and structuring using 8 nuclear microsatellite loci in 794 individuals from 30 sampling sites.

Results: Two major genetic clusters were identified across the range: a southwestern cluster and …