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Recreation Resource Impacts In The Bear Lake Road Corridor Of Rocky Mountain National Park, Colorado, Usa: An Assessment Of Resource Conditions And Visitor Perceptions, Ashley L. D'Antonio

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Visitor use in parks and protected areas inevitably leads to resource impacts. In order to effectively manage for resource impacts, it is important for managers to not only understand ecological aspects of their system but sociological aspects as well. The two papers presented in this thesis used integrated approaches to better understand the current level of resource impacts within the Bear Lake Road Corridor of Rocky Mountain National Park and to explore visitor perceptions of these impacts. The first paper used traditional monitoring and assessment techniques, as well as recently developed methodologies, to determine the current level of resource impacts …

Plastic And Genetic Determination Of Population, Community, And Ecosystem Properties In Freshwater Environments, Leigh C. Latta Iv

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The hierarchy of biological organization, from molecules to ecosystems, describes the relationships among various biological systems. Of particular interest is assessing how the factors that primarily determine the nature of one hierarchical level also have transcendent qualities that affect the ecology and evolution of higher hierarchical levels. The goal of this dissertation was to use a bottom-up approach to examine the transcendent effects of two factors that strongly determine the nature of their associated level of biological organization. The first, phenotypic plasticity, is a primary factor that determines the phenotype of an individual. The second factor, genetic diversity, largely determines …

Evaluating Native Wheatgrasses For Restoration Of Sagebrush Steppes, Jayanti Ray Mukherjee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pseudoroegneria spicata and Elymus wawawaiensis are two native perennial bunchgrasses of North America's Intermountain West. Frequent drought, past overgrazing practices, subsequent weed invasions, and increased wildfire frequency have combined to severely degrade natural landscapes in the region, leading to a decline in the abundance of native vegetation. Being formerly widespread throughout the region, P. spicata is a favorite for restoration purposes in the Intermountain West. Elymus wawawaiensis, which occupies a more restricted distribution in the Intermountain West, is often used as a restoration surrogate for P. spicata. However, since most restoration sites are outside the native range of …

Terrestrial Ecosystem Classification In The Rocky Mountains, Northern Utah, Antonin Kusbach

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Currently, there is no comprehensive terrestrial ecosystem classification for the central Rocky Mountains of the United States. A comprehensive classification of terrestrial ecosystems in a mountainous study area in northern Utah was developed incorporating direct gradient analysis, spatial hierarchy theory, the zonal concept, and concepts of diagnostic species and fidelity, together with the biogeoclimatic ecosystem classification approach used in British Columbia, Canada.

This classification was derived from vegetation and environmental sampling of both forest and non-forest ecosystems. The SNOwpack TELemetry (SNOTEL) and The National Weather Service (NWS) Cooperative Observer Program (COOP) weather station network were used to approximate climate of …

The Effect Of In-Line Lakes On Dissolved Organic Matter Dynamics In Mountain Streams, Keli J. Goodman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research combines observation, experimentation, and modeling to evaluate the influence of lakes on dissolved organic matter (DOM) quantity, quality and export in subalpine watersheds of the Sawtooth Mountain Lake District, central Idaho.

First, I conducted an empirical study of the hydrologic and biogeochemical controls on DOM dynamics in stream-lake fluvial networks. I hypothesized that lakes would decrease temporal variability (i.e., buffer) and alter the characteristics of DOM from inflow to outflow. I tested these hypotheses by evaluating DOM temporal patterns and measuring annual export in seven-paired lake inflows and outflows. I then evaluated how ultraviolet (UV) exposure affected DOM …

Greater Sage-Grouse Seasonal Ecology And Responses To Habitat Manipulations In Northern, Utah, Eric T. Thacker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Declining greater sage-grouse populations (Centrocercus urophasianus; hereafter sage-grouse) have led to increased concern regarding the long-term stability of the species. Previous research has identified factors contributing to the observed population declines. Habitat degradation and loss have been implicated as major factors in population declines. Although much is known about sage-grouse biology, more information is needed about population responses to specific management actions. This research was conducted to document sage-grouse responses to site-specific management actions. Additionally, I evaluated sage-grouse temporal and seasonal habitat-use and the comparability of techniques used by range and wildlife managers to measure vegetation responses of …

Ecological Effects Of Genotypic Diversity On Community And Ecosystem Function, Megan K. Kanaga

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Genotypic diversity within populations can have important evolutionary consequences, but the ecological effects of intraspecific genetic variation on community and ecosystem function have only been studied in a few systems. I present the results of a three-year study designed to address the ecological impacts of genotypic diversity in quaking aspen (Populus tremuloides Michx.), using aspen genotypes planted across genotypic diversity levels (monoculture and mixture) and watering treatment levels (well-watered and water-limited). First, I demonstrated that significant variation exists among genotypes for a wide range of growth, morphological and physiological traits, and quantified high heritability and coefficient of genetic variation …

Vegetation Characteristics Of Wyoming Big Sagebrush Communities Historically Seeded With Crested Wheatgrass In Northeastern Great Basin, Usa, Justin Rodney Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass (Agropyron cristatum [L.] Gaertn.) is one of the most commonly seeded grass species in the western United States and dominates thousands of hectares in the Great Basin. Although many degraded Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) plant communities have been seeded with crested wheatgrass, successional pathways, influence of soil attributes, and cultivation history on the vegetation of these communities have not been fully characterized. I sought to identify community phases, vegetative differences, and soil attributes that explain variation among 35 Wyoming big sagebrush communities historically seeded with crested wheatgrass. All communities were more than …

Seed Banks Of Sagebrush Communities Seeded With Crested Wheatgrass, Kevin L. Gunnell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass (Agropyron cristatum [L.] Gaertn.) is one of the most commonly seeded exotic species in the western United States. Although many degraded Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) plant communities have been seeded with crested wheatgrass during rehabilitation efforts, seed banks of these communities have not been characterized. I sought to characterize and explain the variation among 33 seeded communities in the northeastern Great Basin. Hierarchical clustering and principal components analysis identified four possible seed bank categories in these communities. Seed bank categories varied from high to low crested wheatgrass dominance. The crested wheatgrass-dominated category …

Effects Of Targeted Grazing And Prescribed Burning On Fire Behavior And Community Dynamics Of A Cheatgrass (Bromus Tectorum)-Dominated Landscape, Joel M. Diamond

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies were conducted to determine the effectiveness of using targeted grazing and prescribed burning as tools to reduce fire hazards and cheatgrass (Bromus tectorum) dominance on rangelands in the northern Great Basin. A field study, with four grazing-burning treatments (graze and no-burn, graze and burn, no-graze and burn, and no-graze and no-burn), was conducted on a B. tectorum-dominated site near McDermitt, Nevada from 2005-2007. Cattle removed 80-90% of standing biomass in grazed plots in May 2005 and 2006 when B. tectorum was in the boot (phenological) stage. Grazed and ungrazed plots were burned in October 2005 and …

Consequences Of Vegetation Change On The Dynamics Of Labile Organic Matter And Soil Nitrogen Cycling In A Semiarid Ecosystem, Toby D. Hooker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush-dominated ecosystems are being transformed by wildfire, rangeland improvement techniques, and exotic plant invasions. These disturbances have substantial effects on the composition and structure of native vegetation, but the effects on ecosystem C and N dynamics are poorly understood. To examine whether differences in dominant vegetation affect the quantity and quality of plant organic matter inputs to soil, ecosystem C and N pools and rates of plant turnover were compared among historically grazed Wyoming big sagebrush, introduced perennial crested wheatgrass, and invasive annual cheatgrass communities. Since low soil moisture during the summer may inhibit the microbial colonization of plant detrital …

Application Of Electrified Fladry To Decrease Risk Of Livestock Depredation By Wolves (Canis Lupus), Nathan J. Lance

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wolf (Canis lupus) predation on livestock can cause economic and emotional hardships for livestock producers, complicating the balance of wolf conservation with other human interests. New management tools that decrease risk of predation may offer additional flexibility or efficiency for both livestock producers and management agencies. I examined 1) the efficacy of electrified fladry compared to fladry at protecting a food source from wolves in captivity, 2) the efficacy of electrified fladry for reducing wolf use of pastures and preventing depredations, and 3) the applicability of electrified-fladry. In captivity I tested the reaction from 15 groups (46 wolves) …

Evaluation Of Macroinvertebrates As A Food Resource In The Assessment Of Lotic Salmonid Habitat, Nicholas P. Weber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Criteria used to characterize lotic salmonid habitat are often based on observed correlations between physical habitat characteristics and salmonid abundances. A focus on physical habitat features ignores other habitat components, such as an adequate supply of food that set the physiological limitations on salmonid growth and survival. This study outlines the development of a habitat assessment approach that focuses on how invertebrate food availability interacts with stream temperatures to determine salmonid growth potentials. Abundances of benthic and drifting invertebrate communities, stream temperatures, and juvenile steelhead trout (Onchorhynchus mykiss gairdneri) summer growth rates and abundances were measured within 10 …

Measurement Of Fine Spatial Scale Ecohydrologic Gradients In A Pinyon-Juniper Ecosystem, Matthew David Madsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, …

Sex-Biased Predation On Taricha By A Novel Predator In Annadel State Park, Amber Noelle Brouillette

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Newts of the genus Taricha have long been studied due to the powerful neurotoxin found in their skin. Tetrodotoxin (TTX) acts by blocking receptors in sodium channels, ultimately resulting in death via asphyxiation. The only documented predators of species in this genus have been snakes of the genus Thamnophis. Recently, predation on Taricha in Ledson Marsh in Annadel State Park, Santa Rosa, CA was discovered. Predation was in the form of laceration or evisceration, and tracking of predation from 1998-2008 showed that it was male-biased. Two species of Taricha were found living sympatrically at this location, the California newt …

The Genetics Of Colonization In Two Amphibian Species After The 1980 Eruption Of Mount St. Helens, Kristin Ann Bakkegard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The genetics of colonization is understudied in salamanders but has large conservation implications as new habitats are formed or restored to their previous condition. The 1980 eruption of Mount St. Helens provided a natural experiment to study the genetic effects of a large infrequent environmental disturbance on two species of salamander, Taricha granulosa (Rough-skinned newt) and Ambystoma gracile (Northwestern salamander). Both these species breed in ponds, and are thought to exhibit high breeding site fidelity and low vagility. I designated three treatments based on the effects of the eruption: new ponds (created by the eruption, immigrants only), recovery lakes (in …

A Conceptual Framework For Understanding Effects Of Wildlife Water Developments In The Western United States, Randy T. Larsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Free water can be a limiting factor to wildlife in arid regions of the world. In the western United States, management agencies have installed numerous, expensive wildlife water developments (e.g. catchments, guzzlers, wells) to: 1) increase the distribution or density of target species, 2) influence animal movements, and 3) mitigate for the loss of available free water. Despite over 50 years as an active management practice, water developments have become controversial for several species. We lack an integrated understanding of the ways free water influences animal populations. In particular, we have not meshed understanding of evolutionary adaptations that reduce the …

Garter Snake (Thamnophis) Natural History: Food Habits And Interspecific Aggression, Michael J. Edgehouse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Communication and recognition are closely intertwined and have been well documented in closely related species over the past several decades. These two types of behaviors often will aid in fostering or disrupting coexistence of similar species. Frequently, it is through different diet patterns that similar species will be able to coexist. This study uses data from 1972 through 2006 to demonstrate the diet of Thamnophis sirtalis, T. atratus, T. elegans, and T. couchii throughout their California range of sympatry with Taricha torosa. Additionally, an in depth examination of the diet of T. sirtalis, T. elegans, …

Breeding Behavior And Space Use Of Male And Female Mule Deer: An Examination Of Potential Risk Differences For Chronic Wasting Disease Infection, Leslie R. Mcfarlane

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The dynamics of pathogen and host relationships relative to disease transmission in wildlife populations are important ecological processes to understand, particularly since spatial dynamics of disease can be driven by movement, behavior, and dispersal of animals. Chronic Wasting Disease (CWD) is an example of this important interface, where little is known regarding origin of the disease or routes of transmission. Surveillance data for CWD in free-ranging mule deer indicates that breeding-age male deer have 2-4 times higher prevalence rates than females or younger age males. In an effort to understand differences that might increase risk for exposure to CWD infective …

Factors Influencing Epiphytic Lichen Communities In Aspen-Associated Forests Of The Bear River Range, Idaho And Utah, Paul C. Rogers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing habitat, thereby threatening their long-term local and regional viability. Though lichens have a rich history as air pollution indicators, I believe that they may also be useful as a metric of community diversity associated with habitat change. To date, few studies have specifically examined the status of aspen's epiphytic lichen …

Examination Of The Ecological Differences Between Two Closely Related Endemic Whitefish In Relation To Growth Conditions And Predation Risk, Benjamen M. Kennedy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Benthic Bear Lake whitefish (Prosopium abyssicola) and Bonneville whitefish (P. spilontus) are closely related, yet the extent of ecological separation remains poorly understood. We described their spring and summer distribution and diet in Bear Lake and examined how these were related to environmental growth conditions, and predation risk. In spring and summer, Bonneville whitefish dominated shallower depths (5-30 m), whereas Bear Lake whitefish dominated deeper depths (45-55 m). At intermediate depths (35-40 m), low numbers of both species occurred. Bonneville whitefish ate mostly Chironomidae, whereas Bear Lake whitefish ate mostly Ostracoda. Habitats occupied by Bonneville whitefish …

Effects Of Fire Disturbance On Terrestrial Salamanders In Mixed-Coniferous Forests Of The Klamath/Siskiyou Region Of The Pacific Northwest, Donald J. Major

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An effective examination of fire disturbance on floral and faunal components requires research that integrates knowledge from multiple disciplines to understand the pattern and process controls affecting organisms in a complex system. However, current fire effects research typically focuses on the pattern response of organisms or their habitats with little integration of the dynamic fire process that created the pattern. This dissertation integrates an analysis of the processes of fire disturbance with terrestrial salamander ecology in a fire-dependent forest ecosystem, Klamath Province, California, USA.

In Chapter 1, I begin with a comprehensive review of disturbance ecology, focusing primarily on fire …

Cattle As Grazing Management And Seed Dispersal Tools For Increasing Native Species Diversity On Great Basin Rangelands, Marina K. Whitacre

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A series of experiments evaluated: 1) the influence of seed intake and gut retention time on seed passage, recovery, and germinability; 2) fecal seeding and broadcast /trampling as techniques to incorporate seeds into a well-established Agropyron desertorum (Fisch.) Schult. stand in Skull Valley , Utah; 3) intensive grazing as a means to reduce Agropyron biomass and increase establishment and survival of seeded species; and 4) the recovery and germinability of seed extracted from dung collected from the field. Two shrubs (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young and Atriplex confertifolia Torr. & Frem.), a grass (Elymus elymoides (Raf.) …

A Longitudinal Analysis Of Socioeconomic Differences In Obesity And Weight Change During The Early Adult Years, Young-Taek Kim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Obesity has reached epidemic proportions in American society. However, not enough attention has been given to weight change by temporal and dynamic detailed social characteristics, controlled for unobserved heterogeneities nested in county and state. Using the National Longitudinal Survey Youth (NLSY79), this study examined weight change and its development into unhealthy conditions like being overweight or obese, in relation to change in social characteristics including life course events. This study also examined the social characteristics of remaining at a normal weight through all time intervals over a 19-year period. Using hierarchical linear multilevel analysis, this study found that changes in …

Species Pairwise Associations Over Nine Years Of Secondary Succession: Assessing Alternative Explanations And Successional Mechanisms, Lara R. Rozzell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The importance and mechanisms of species interactions are undetermined in most successional systems. I used correlations and null modeling to detect pairwise species associations between 33 plant species in the first nine years of secondary succession after logging and burning in a western Oregon Cascade forest. I tested for correlations between each species and soil nutrients, nonvegetative ground cover, and surrounding vegetation. More positive than negative associations were found at all sampling times. The proportion of positive associations decreased and negative associations increased through time. Up to 42% of associations at a sampling time were explicable by shared positive correlations …

Coyote Foraging Ecology, Vigilance, And Behavioral Cascades In Response To Gray Wolf Reintroduction In Yellowstone National Park, T. Adam Switalski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vigilance behavior can aid in the detection of predators and may also play a role in observation of conspecifics, in food acquisition, and in the prevention of kleptoparasitism. However, in most occasions, vigilance is most important as an antipredator function. Generally, factors that increase the risk of predation also increase the amount of vigilance. We examined whether the reintroduction of the large predator, the wolf, in Yellowstone National Park (YNP) would influence coyote vigilance and foraging ecology. From December 1997 to July 2000, we collected 1743 h of coyote activity budgets. Coyote home ranges occurred within wolf territories (termed high-use …

Statmod: A Tool For Interfacing Arcview® Gis With Statistical Software To Facilitate Predictive Ecological Modeling, Christine M. Garrard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As geographical information systems and spatial data become more accessible, predictive spatial modeling in ecology is becoming more common. Unfortunately, not all ecologists possess the necessary skills to successfully combine statistical models and geographical information systems. In response to this problem, I wrote an extension for ArcView^® GIS called StatMod. This extension interfaces ArcView GIS with SAS^® and S-PLUS^® statistical software and walks the user through creating and mapping logistic regression and classification and regression tree models.

StatMod was then used to run a series of analyses that would have been difficult without such a tool. A …

Morphometric Evaluation Of The Whitefish Complex In Bear Lake, Utah/Idaho, Alan Ward

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whitefish populations around the world have long been difficult to categorize taxonomically. The whitefish of Bear Lake, Utah/Idaho are no exception. There are three recognized species of Prosopium that are endemic to the lake. Two of these species, Prosopium spilonotus and Prosopium abyssicota, have previously been indistinguishable outside of spawning times. Previous studies have proposed additional taxa within P. spi/onotus to further complicate the identification among these taxa.

Morphological characteristics were quantified on wild whitefish from Bear Lake, as well as from progeny reared in the laboratory from the wild adult fish. The purported taxa were separated in the field …

Hydrogeomorphic Factors Influencing Clonal Recruitment Of Cottonwoods In Mountain Valleys, Michael D. Roberts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Riparian cottonwoods (populus spp.) are keystone pioneer species that contribute to critical streamside and in-stream habitats, water quality, and aesthetic and recreational value. Land use and river regulation have caused a widespread reduction in the extent and regeneration of this genus. The majority of research on Populus species' reproduction has examined seedling recruitment that dominates in wide alluvial valleys. In contrast, I evaluated reproductive strategies of Populus angustifoliain mountain valleys. Research was conducted in northern Utah on the Little Bear River, a gravel-bedded stream that flows north out of the Bear River Range onto deposits of Ancient Lake …

Modeling Habitat Attributes Of Cavity-Nesting Birds In The Uinta Mountains, Utah: A Hierarchical Approach, Joshua J. Lawler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Birds may have the ability to view their environments at a wide range of spatial scales; accordingly, they may make habitat-selection decisions at multiple spatial scales. I investigated the implications of hierarchy theory and a landscape perspective on nest-site selection in cavity-nesting birds in the Uinta Mountains in northeastern Utah. I used three different approaches to address the concept of a multi-scaled nest-site selection process. First, I conducted an exploratory study in which I investigated nest-site selection at three spatial scales for Red-naped Sapsucker (Sphyrapicus nuchalis), Northern Flicker (Colaptes auratus), Tree Swallow (Tachycineta bicolor), and …