Terrestrial and Aquatic Ecology Commons^™

Patterns In Winter Stonefly Distribution Along A River Continuum And Land-Use Gradient In Northwest Arkansas Streams, Zachary Tipton

Graduate Theses and Dissertations

Freshwater ecosystems are facing a crisis with extinction rates of aquatic species exceeding those of their terrestrial counterparts by up to fivefold. This decline is predominantly attributed to evolving land use patterns within watersheds, leading to chemical and physical transformations in freshwater habitats. Northwest Arkansas (NWA) represents one of the fastest-growing regions in the United States, undergoing substantial shifts in land use. Consequently, the status of aquatic life in this region remains uncertain. Addressing this concern, the latest Arkansas Wildlife Action Plan emphasizes the necessity of distribution and population data to guide conservation efforts for Species of Greatest Conservation Need …

Factors That Affect Home Range Of Timber Rattlesnakes (Crotalus Horridus) In Northwest Arkansas, Bannon Gallaher

Graduate Theses and Dissertations

Conservation of animal populations requires knowledge of their habitat and spatial needs. Quantifying spatial requirements involves the analysis of home range. We examined the effects of sex, body size (SVL), body condition (log mass/log SVL), and year on home range in Timber Rattlesnakes (Crotalus horridus) in Northwest Arkansas. Individual locality data from an ongoing, 22+ year radio-telemetry study in Madison Co., Arkansas were analyzed using both minimum convex polygon (MCP) and Kernel Density Estimates (KDE). Plots of the number of sequential observations versus home range (MCP and KDE) determined that a minimum of 25 locations per individual per active season …

Effects Of Landscape And Yard Features On Mammals In Residential Yards In Northwest Arkansas, Emily Johansson

Graduate Theses and Dissertations

The human footprint is rapidly expanding, and wildlife habitat is continuously being converted to human residential properties. Most wildlife residing in developing areas are displaced to nearby undeveloped areas. However, some animals can coexist with humans and acquire the necessary resources (food, water, shelter) within the human environment. This may be particularly true when development is low intensity, as in suburban yards. Due to the wide variety in how homeowners utilize their yards, they can be considered individually managed “greenspaces.” These yards can provide a range of food (e.g., bird feeders, compost, gardens), water (bird baths and garden ponds), and …

Seasonal Patterns In Activity And Occupancy Dynamics Of The Imperiled Spotted Turtle (Clemmys Guttata), Ellery Vaughn Lassiter

Graduate Theses and Dissertations

Wetland ecosystems are often spatially patchy across a landscape and exhibit seasonal patterns in water levels, resulting in the need for aquatic wildlife to use several different wetland patches across a season. The ecology of semi-aquatic freshwater turtles is especially complex because individuals often move among a variety of habitats to meet life history needs and these habitat requirements often differ across a season. Understanding the temporal and spatial scale in which turtles move and distribute across the landscape is vital for effective management, especially in the face of continued habitat fragmentation and climate change. Thus, we sought to understand …

Conservation Of Open-Canopy-Associated Wildlife: Multi-Scale Management Impacts On Imperiled Herpetofauna, Ethan Joseph Royal

Graduate Theses and Dissertations

The loss of open-canopy ecosystems throughout North America has precipitated declines in reptile and amphibian species associated with these habitat types. Current efforts to restore open-canopy ecosystems are underway in many areas, but the local distributions of, habitat characteristics required by and the effects of management actions on many herpetofauna species are poorly understood or entirely unknown. Research examining relationships among herpetofauna and their environments is often complicated by the extremely low detectability seen in many studies. We used landscape-scale, assemblage-level surveys to investigate the occupancy patterns and habitat associations of open-canopy-associated herpetofauna in two regions, as well as gain …

Allelopathic Effect Of Cereal Straw Extracts On Growth Of Raphidocelis Subcapitata And Microcystis Aeruginosa, Holly Wren

Graduate Theses and Dissertations

Harmful algal blooms are increasing in size, duration, and intensity around the globe. For several decades, cereal straws have been recognized as a viable algal control method, though the mechanisms by which cereal straws inhibit algae remain a topic of research. The objectives of this study were to evaluate the effectiveness of decomposing cereal straw extract, particularly rice (Oryza sativa) and barley (Hordeum vulgare) straw extract, to inhibit the green alga Raphidocelis subcapitata or cyanobacteria Microcystis aeruginosa in bioassays and to determine if the effectiveness of decomposing rice straw extract is altered by the presence of natural organic matter or …

Riverscape Community Genomics Of Ozark Fishes: A Comparative Framework To Infer Ecological And Evolutionary Determinants Of Genetic Diversity, Zachery D. Zbinden

Graduate Theses and Dissertations

Genetic variation is a crucial component of biodiversity and represents the variability and spatial structure of alleles within and among organisms. Evolution modulates this variability over time through mutation, selection, gene flow, and genetic drift. However, our capacity to test foundational theories of population genetics has always been at the mercy of molecular approaches available to quantify patterns of genetic diversity. Initially, techniques for empirical DNA studies were in their infancy and limited by technologies and the price per unit of genetic information. Because of these constraints, our pursuits have generally been limited to investigations of one or a few …

Competing Behaviors Of Thermoregulation And Ambush Foraging In The Timber Rattlesnake (Crotalus Horridus Horridus): A Mechanistic Assessment Of Thermal Conduction, Larry K. Kamees

Graduate Theses and Dissertations

The interaction between the biophysical environment and ectotherm morphology elicits behaviors designed to maintain internal body temperature (Tb) within a range that promotes physiological functions. The short-term requirements of mass (energy requirements) and heat balance are subject to tradeoffs imposed by the organisms current physiological (heat and mass budgets) and environmental (biophysical, demographic, social, and predation) constraints and available resources. In temperate forests, extreme temperatures are common in summer even with intermittent sun exposure due to dense canopy cover. In Spring and Fall, temperatures can range from below freezing to 35 ℃ in 24 hrs. An ambush predator like the …

Bacterial Chondronecrosis With Osteomyelitis In Broilers: Genomics, Phylogenomics, And Methods To Detect Specific Pathogens During Outbreaks., Abdulkarim Abdulaziz A. Shwani

Graduate Theses and Dissertations

Lameness is a major issue in animal welfare and the broiler industry. Bacterial chondronecrosis with osteomyelitis (BCO) is one of the main causes of lameness. Many staphylococcal species, including Staphylococcus agnetis isolate 908, have been isolated from the bones and blood of lame broilers at the University of Arkansas. Staphylococcus agnetis is a coagulase-variable, Gram-positive bacterial species that has been previously associated with subclinical or mild clinical cases of mastitis in dairy cattle. The annotated complete genome of hypervirulent strain 908 was published at NCBI. In this study, it has been compared to nine genomes we assembled for hypervirulent isolates …

Reconstructing Bison And Mammoth Migration During The Late Pleistocene And Early Holocene Of Central Texas Using Strontium Isotopes, Joshua John Porter

Graduate Theses and Dissertations

During the Late Pleistocene (LP; past 130,000 years), over two-thirds of large mammal (>45kg) species went extinct globally. While the role of humans is hotly debated, the effect of these extinctions is growing clearer; the extinctions resulted in widespread and lasting faunal community reorganization. However, the impact of these extinctions on dietary and migratory behavior within faunal communities is unknown. Our study examines the impact of the megafaunal extinctions on the dietary and migratory behavior of surviving Bison individuals in Texas using carbon, oxygen, and strontium isotopes. Strontium isotopes are incorporated into mammalian enamel during their tooth development and …

The Effects Of Commercial Harvest On The Density And Demography Of Aquatic Turtles In Arkansas, Andrhea Darleen Massey

Graduate Theses and Dissertations

The United States is home to the second highest concentration of turtle species in the world, after Asia. As of 2018, there are 57 turtle species recognized within the US, 40% of which are listed as threatened or endangered, with the primary threats to population persistence identified as over-consumption and/or habitat loss. Within the US, the Mississippi Alluvial Valley (MAV) region represents the second highest turtle species richness, after the Mobile River Basin. The MAV region of Arkansas is one of the least regulated in terms of commercial aquatic turtle harvest and has undergone large-scale habitat conversion from bottomland hardwood …

Body Mass And Body Condition Variation Of Mallards (Anas Platyrhynchos) Within And Among Winters Within The Lower Mississippi Alluvial Valley, John Thompson Veon

Graduate Theses and Dissertations

Most North American waterfowl overwinter in southern North America before migrating back to breeding grounds in the northern US and Canada. These species face the challenge of needing to maintain or increase their body mass during an environmentally difficult winter period. Successful body mass maintenance during the winter period has major ramifications not only for their winter survival but for their fitness across the entire year. Recent research in Europe and the western United States suggests that the body mass of mallards (Anas platyrhynchos) has increased from the late 1960s to early 2000s. However, the factors responsible for increases in …

Habitat Assessment Of Ozark Glades Using Selected Epigeal Predatory Arthropods, Austin Key Jones

Graduate Theses and Dissertations

Epigeal predatory arthropods were collected with pitfall-style traps in nine sandstone glades of varying ecological stages, and management histories, in the Ozarks of Northern Arkansas over three years. These sites were categorized into three Site Types; Intact, high quality glades; Degraded, forest-encroached glades, and Restored glades which had received woody vegetation removal and burning. Collections of ground spiders (Gnaphosidae), predatory ground beetles (Carabidae), and the sole species of scorpion present in the Ozarks, Centruroides vittatus, were reported on as well as the applicability of arthropod collection methods for glade habitat assessment. Habitat characteristics were recorded for each site and analyzed …

Establishment Of Pollinator Habitat Within A Livestock Pasture Ecosystem, Roshani Sharma Acharya

Graduate Theses and Dissertations

Pollinators are important for fertilization, setting fruits, and seed development of more than 78% of the flowering plants that provide food for human beings and other species. Use of pollinators to maximize crop production is a proven agricultural practice; however, it has been less explored in livestock forage production systems. This study investigated pollinator abundance and diversity in pastures using different sampling methods and determined the impact of different pasture management practices on insect pollinators in a livestock pasture ecosystem. In Chapter 2, utility of four different colors of pan trap (blue, green, yellow, and purple) for sampling bees in …

Host-Parasite Interactions Within Food Webs, Adam Zvanut Hasik

Graduate Theses and Dissertations

Parasitism is one of the most common life history strategies employed in nature, yet the effects of parasites are often thought to be minimal, and the vast majority of studies fail to consider parasites and their effects on host organisms. This is likely a problem, as the magnitude of parasite-mediated effects on their hosts can be quite large. Additionally, the effects of parasites are known to extend beyond the host to affect other species interactions. I used a series of approaches to gain a more integral understanding of host-parasite interactions by studying (1) the effects of parasites on biotic interactions …

Influence Of Local- And Landscape-Scale Factors On Avian Assemblage In Fragmented Tallgrass Prairie Landscape, Pooja Panwar

Graduate Theses and Dissertations

Agricultural expansion and increasing urbanization are driving rapid landscape modification in the Tallgrass prairies ecosystem and are affecting biodiversity at multiple spatial scales. Thus, the conservation of fragmented grassland and steeply declining grassland avifauna is dependent on the relationship between local- and landscape-scale factors and avian assemblage. We also need to understand how these factors, operating at different spatial scales, drive the occupancy of different guilds in the assemblage. We conducted repeated point count surveys during the breeding season of 2019 at 66 grassland sites across Arkansas and Missouri, USA. We developed a multi-species occupancy model to estimate species richness, …

Population Connectivity Of The Eastern Collared Lizard Crotaphytus Collaris In Arkansas, Whitney Allison Murchison-Kastner

Graduate Theses and Dissertations

Habitat reduction and fragmentation can isolate populations and decrease genetic diversity, making them susceptible to local extirpation. Additionally, geographic barriers can further impede dispersal among populations thus reducing gene flow. Field studies suggest these factors may be responsible for the decline in Eastern Collared Lizard (Crotaphytus collaris) populations in Arkansas. To address the impacts of habitat loss and fragmentation on the Eastern Collared Lizard (C. collaris) in Arkansas, I used DNA fragment analysis to examine genetic diversity, population structure and connectivity among C. collaris populations. I do so herein by employing microsatellite data from 138 adults across 11 loci to …

Role Of Reptile-Invertebrate Interactions In Enigmatic Reptile Declines, Meredith Swartwout

Graduate Theses and Dissertations

Reptile populations are declining world-wide and the mechanisms behind many of these declines remain enigmatic. Food web interactions (i.e., reduced prey availability or increased predation) have been implicated behind some reptile declines. However, relatively little is known about predation on lizard and snake eggs, despite egg survival being important for population dynamics of some species. Ants are important predators of squamate reptile eggs in tropical and temperate systems. In Costa Rica, long-term declines in terrestrial anole lizards were linked with reduced leaf litter depth, a factor that could influence egg vulnerability to ant predation. Fire ants (genus Solenopsis) are aggressive …

Spore Dispersal Of Slime Molds And Higher Fungi Via Animal Vectors, Courtney Trimble

Graduate Theses and Dissertations

Myxomycetes and dictyostelids are Amoebozoans that are cosmopolitan inhabitants of a variety of habitats, particularly forest environments. Both groups reproduce using spores which are primarily dispersed via wind in myxomycetes but this characteristic poses a problem for dictyostelids. The spores of dictyostelids are incased in a mucilaginous matrix that makes wind ineffective except in exceptional cases. It has been suggested that animals such as birds may play an important yet understudied role in the dispersal of these organisms. This study investigated how animals could potentially serve as vectors for spore dispersal of dictyostelids and myxomycetes with some limited data obtained …

Climate-Driven Impacts On Himalayan Aquatic Biodiversity: A Case Study Involving Snowtrout (Cyprinidae: Schizothorax), Riri Wiyanti Retnaningtyas

Graduate Theses and Dissertations

Monitoring biodiversity, to include its relative dispersal and contraction, has become a conservation task of great importance, particularly given the catastrophic and ongoing loss of habitat due to climate change. However, the timing, direction, and magnitude of these rates vary across taxa and ecosystems. Predicting specific impacts of climate change can thus be difficult and this, in turn, hampers management action. Metrics are needed to not only quantify contemporary requirements of species, but also predict potential distributions that fluctuate in lockstep with climate.

Montane ecosystems in the Himalayas are highly impacted by climate change, yet remain largely understudied due to …

Of Biodiversity, Boundaries, And Distribution: The Myxomycetes Of The Philippines And Beyond, Sittie Aisha Bustamante Macabago

Graduate Theses and Dissertations

This dissertation contains a compilation of independently performed studies primarily focusing on the myxomycetes (plasmodial slime molds) from the Philippines and integrating local and worldwide data to demonstrate regional and global trends. The major themes include the following: (I) a review of the diverse group of spore-producing amoeboid protists, including the myxomycetes; (II-IV) diversity assessments in three different groups of islands in the Philippine archipelago; (V) mapping the myxomycetes found in the Philippines for databasing and analyzing the geocoded data; (VI) a study on regional boundaries, including the Philippines, using myxomycete species composition; and, (VII) creating a global species distribution …

The Effects Of Multiple Stressors On Stream Communities: The Convergence Of Drought, Nutrient Pollution, And Invasive Species, Robert Joseph Fournier Iii

Graduate Theses and Dissertations

Freshwater systems experience multi-faceted degradation from a variety of ecological and environmental stressors. Three common stressors in these systems, drought, nutrient pollution, and invasive species, have wide-ranging effects on stream population- community- and ecosystem dynamics. We have a broad understanding of how each of these stressors works to influence stream systems independently. However, we still know relatively little about if, and how, these stressors might interact when they co-occur. Though drought is a natural part of many stream systems, all three of these stressors can be exacerbated or facilitated by anthropogenic actions. Accordingly, as human population and resource use continue …

Neogene And Quaternary Events Shaped Diversification And Speciation In Bhutanese Rheophilic Fishes Of The Family Nemacheilidae (Cypriniformes) And Sisoridae (Siluriformes), Karma Wangchuk

Graduate Theses and Dissertations

Biogeography of the Himalayan region [to include the Qinghai-Tibetan Plateau (QTP)] evolved over a ~30M year span, catalyzed by the collision of the Indian and Eurasian plates. The resulting uplift produced major ecological and climatic effects, that in turn drove the diversification of biodiversity. As a result, the QTP is designated as a global biodiversity hotspot particularly vulnerable to cumulative climatic effects, including shrinking distributions, declining numbers, and local extinctions. Understanding how the biodiversity within the Himalaya/ QTP was established and maintained is a necessary first step in prioritizing conservation efforts.

Fishes in global montane regions, such as the Himalaya, …

Using Soil Geospatial Properties And Environments To Explore Microbial Diversity, Sharon Faye Smith

Graduate Theses and Dissertations

Soil microorganisms help maintain nutrient cycling, control carbon sequestration, impact plant productivity, and influence several soil chemical and physical properties; yet, the processes that control the microbial composition of soil and how environmental changes may affect the composition and activity of these organisms at different scales remains a difficult and intriguing puzzle for soil scientists, ecologists, and modelers. Wetlands are endangered and important ecosystems that provide several services, which are directly linked to soil function. However, few wetland assessments consider the soil environment and microbial ecology. Linking soil microbial community composition and distribution patterns to soil physio-chemical properties would provide …

A Macroevolutionary View On Extinction In Aves, Chiroptera, And Odonata, Peter Hasik

Graduate Theses and Dissertations

A central goal of conservation biology is to identify and understand the factors that lead to extinction. The Earth is currently undergoing a 6th mass extinction event, in large part because of human activity. In the last century, rates of extinction have increased anywhere from 8-100 times the background rate of 2 extinctions per 10,000 species every 100 years. However, there remains a debate over whether certain species are predisposed to a higher extinction risk. In particular, it is not known if the macroevolutionary history of a lineage is a major contributor to the probability of extinction, nor is it …

Environmental Influences On Tree-Driven Karst Bedrock Physical Weathering, Cole Robert Jimerson

Graduate Theses and Dissertations

The role of tree roots as stressors that contribute to physical weathering processes and thus soil generation remains an open question in critical zone science. While evidence suggests roots may be able to damage rock by accessing pre-existing fractures, where they can expand due to water uptake or generate forces on rock in response to wind gusts, these processes have not been investigated in temperate karst regions until now. I monitored forces at the root-rock interface for an American elm and Hackberry tree between September 2019 and May 2020. I used piezoelectric force sensors to determine if differences in species, …

A Comparative Ecological Study Of Limestone And Dolomite Glades In The Ozark Mountains Of Northwest Arkansas, Brittney Booth

Graduate Theses and Dissertations

Glades are one of the many habitats that exist in the Arkansas Ozarks and contribute to the overall biodiversity of the state of Arkansas. For this study, five dolomite glades and five limestone glades in the Ozarks of northwest Arkansas were studied from March to October in the years 2017 and 2018 to determine the similarities or differences that might be present. One hundred and fifteen vascular plant taxa were documented in the dolomite glades and one hundred and three vascular plant taxa were documented in the limestone glades. Forty-six vascular plant taxa were unique to the dolomite glades and …

Effects Of Light, Nutrients, And Salts On Microbial Biofilm Productivity And Detrital Processing In Aquatic Mesocosms, Bethanie Brooke Howard-Parker

Graduate Theses and Dissertations

Anthropogenic activities associated with urbanization, agriculture, and resource extraction continue to increase to support increasing needs of the growing population. These activities increase the amounts of pollutants entering freshwater streams and put aquatic ecosystems at structural and functional risk. Aquatic microbes play an important role in detrital processing in streams as a key linkage in moving carbon from detrital stocks into aquatic food webs. My research investigates the effects of light, nutrients, and salts on detrital microbes and decomposition in freshwaters using a mesocosm approach. In chapter one, I modified a current priming effect (PE) hypothesis model to include light …

A Comparative Taxonomic And Diversity Study Of Litter-Associated Fungi In Northwest Arkansas Forests, Rajaa Abdulrazzaq Abbas Al Aanbagi

Graduate Theses and Dissertations

Fungi are taxonomically the most species-rich group of organisms on the earth, ecologically occupy distinctive niches and interact with diverse other organisms throughout their biogeographic distributions and functionally play key roles through their various lifestyles. Plant litter, in particular, is a keystone component in ecosystems and provides heterogeneous microhabitats for the often overlooked litter-decomposing fungi and other organisms on the floor of temperate deciduous forests. Litter fungi involve indirect interactions with the plant, soil and whole food web network. However, the community structure and functions of litter-associated fungi as well as patterns of species richness distributed across various litter microhabitats …

Soil Microbial Diversity And Litter Decomposition Increase With Time Since Land Use Disturbance In Tropical Montane Forests Of Malaysian Borneo, Renee Sniegocki

Graduate Theses and Dissertations

Logging and forest conversion are occurring at alarming rates in the tropical forests of Southeast Asia. These disturbances alter soil chemistry, microbial diversity, and disrupt carbon cycling through shifts in litter decomposition. Direct links between microbial diversity and soil properties such as pH are well established; however, the indirect impacts of logging and forest conversion on microbial diversity and litter decomposition are poorly understood. We used surface (5 cm) soil to assess soil physicochemical properties, next-generation DNA sequencing to assess soil microbial diversity, and standardized litterbags to assess litter decomposition stabilization at five sites along a land use disturbance gradient …