Life Sciences Commons^™

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Graduate Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment zones’ (PICZ) and …

Eucalyptus In Kenya; Impacts On Environment And Society, Brandy M. Garrett Kluthe

Graduate Theses and Dissertations

Eucalyptus trees were introduced to Kenya a little over a century ago. European colonization along with the development of a railway system increased the demand for a fast growing wood source. The expansion of the tree across the fertile lands in Kenya raises concerns about the environmental impact on ecosystems where it has been introduced. These concerns include degraded soils, loss of water resources, co-introduction of ectomycorrhizal species, and allelopathy. Economic benefits to local landowners were also explored as well as the potential for large Eucalyptus woodlots to maximize the sequestration of CO₂ from the atmosphere. This was examined through …

Emergence Phenology And Nematode Associates Of The Woodwasp, Sirex Nigricornis F. (Hymenoptera: Siricidae), In Arkansas And Mississippi Forests, Jessica Ann Hartshorn

Graduate Theses and Dissertations

Sirex nigricornis F. (Hymenoptera: Siricidae) is a native woodwasp in eastern North America that inhabits dead and dying pine trees during its univoltine development. Sirex noctilio is native to Eurasia and North Africa and was discovered in the northeastern United States in 2004 after a century of accidental introductions across the Southern Hemisphere. Since then, it has spread to seven states and southern Ontario. There is concern about its potential to negatively affect the multi-billion dollar pine timber industry of the southeastern United States. Effective monitoring tools are necessary to track the spread and establishment of S. noctilio. Deladenus siricidicola …

Dietary Effects On The Stoichiometry Of Growth, Regulation, And Wastes Of Ozark Stream Insect Detritivores, Halvor Matthew Halvorson

Graduate Theses and Dissertations

A widespread stressor, anthropogenic nitrogen (N) and phosphorus (P) pollution can increase resource nutrient content and alter animal community composition in freshwater ecosystems. In this dissertation, I used ecological stoichiometry theory to examine effects of diet nutrient content and leaf litter type on growth, regulation, and wastes of aquatic invertebrate detritivores. I tested effects of leaf litter diet carbon:phosphorus (C:P) on growth and stoichiometric regulation of the detritivorous caddisfly Pycnopsyche lepida and used results to determine a threshold elemental ratio of oak litter C:P=1620 that confers peak growth of this species. This empirical, growth-based approach provided a more accurate estimate …

The Role Of Hydrologic Regimes In Driving Morphologic Divergence And The Trait Compositions Of Fish Assemblages, Lindsey A. Bruckerhoff

Graduate Theses and Dissertations

The hydrologic regime is an important determinant of the ecological integrity of a stream. Hydrologic regimes are defined by the magnitude, timing, frequency, rate of change, and duration of high and low flow events and capture long term patterns of variability and predictability of water movement in a stream. Flow regimes influence many aspects of the biophysical environment in lotic systems; therefore organisms have adapted to natural flow patterns. We investigated how fish have adapted to flow regimes at both a population and community level. In the first study presented in this thesis, we hypothesized fish exhibit phenotypic divergence to …

Responses Of Semi-Aquatic Snakes To Drought, Philip Nicholas Vogrinc

Graduate Theses and Dissertations

Aquatic ecosystems and their associated wildlife are threatened by alteration in the frequency and intensity of precipitation events predicted to affect many regions as a consequence of global climate change. Semi-aquatic snakes serve important roles as predators and prey within aquatic ecosystems, yet little is known about the effects of drought on these species due to their secretive behavior. Long-term studies at an isolated wetland in South Carolina found that drought caused populations of banded watersnakes (Nerodia fasciata) and Florida green watersnakes (Nerodia floridana) to crash. Alternatively, black swamp snakes (Seminatrix pygaea) fared well, exhibiting a resistance strategy by aestivating …

The Abundance And Distribution Of Mallards In The Lower Mississippi Alluvial Valley Of Arkansas, John Andrew Herbert

Graduate Theses and Dissertations

The management of wintering waterfowl in North America requires flexibility because of constantly changing landscapes and conditions. Many mallards use the lower Mississippi Alluvial Valley (MAV) for wintering habitat, making this an area of emphasis for improving management strategies. In this study, I used mallard observation data from 2009-2014 aerial surveys collected in the Arkansas portion of the lower MAV to explain the abundance and distribution and of mallards. Using spatial hierarchical models and breaking covariate data to 2x2 km grid cells, I analyzed how covariates relate to the changes of abundance and distributions within and among surveys. Mallard abundance …

Hydrology-Biology Response Relationships In The Ozark Highlands, Dustin Thomas Lynch

Graduate Theses and Dissertations

I examined flow-ecology relationships among stream communities in the Ozark Highlands, USA. I sampled fish, crayfish, and benthic macroinvertebrates during two consecutive summers, including a drought year (2012) and a flood year (2013). Biological response variables related to community structure were assessed via two different statistical methods: an Information Theoretic approach relating response variables to a priori selected predictor variables incorporating hydrology, habitat, geomorphology, and water quality, and canonical ordination using forward selection to relate these same response variables to a large assortment of hydrologic metrics. In addition to assessing metrics related to predicted natural flow, flow alteration at gaged …

An Inventory Of Endemic Leaf Litter Arthropods Of Arkansas With Emphasis On Certain Insect Groups And Diplopoda, Derek Alan Hennen

Graduate Theses and Dissertations

Endemic arthropods of Arkansas were sampled and their nomenclature and distributions were updated. The Arkansas endemic species list is updated to 121 species, including 16 species of millipedes. A study of the millipedes of Arkansas was undertaken, and resulted in the first checklist and key to all millipede species in the state. 68 species are known from Arkansas, including the genera Cylindroiulus and Polydesmus. The first state records for Ophyiulus pilosus, Cylindroiulus sp., and Ptyoiulus coveanus are reported, and new county records are reported for 16 species. This represents the first key to a state's species since 1980, and the …

Spring Migration Ecology Of American Woodcock (Scolopax Minor) In The Central Management Region Of The United States, Cari Elizabeth Sebright

Graduate Theses and Dissertations

American woodcock (Scolopax minor) is a migratory game bird in population decline since the start of monitoring in 1968. Researchers are interested in gaining knowledge of spring migration ecology to improve migration habitat and mitigate population decline. I captured six woodcock with mist and hand nets on nocturnal habitat and marked them with VHF (very high frequency) transmitters in northern Arkansas. I documented the distance they traveled between nocturnal and diurnal habitats (n=27), and documented diurnal vegetation characteristics at sites used (n=25). I found that woodcock moved an average of 370 m (SE 25.31 m) with the longest movement being …

The Functional And Distributional Ecology Of Mycetozoans Under Changing Edaphic And Climatic Dynamics, Geoffrey Lloyd Zahn

Graduate Theses and Dissertations

Investigations into the distribution and ecosystem functions of fruiting amoebae revealed that local-scale environmental conditions can largely explain broad biogeographical patterns in species assemblage, the way in which amoeboid predators shape bacterial communities and how this top-down influence may affect global biogeochemical processes in a changing climate. The distribution and assemblage of protosteloid amoebae on the islands of New Zealand and Hawaii did not yield any expected patterns of island biogeography, and conformed to other global regions studied. The strongest predictor of species richness in a given region was sampling effort and these species do not appear to have any …

Population Structure Of Central Stoneroller (Campostoma Anomalum) On The Ozark Plateau In Arkansas And Missouri, Mallory Jane Jeffers

Graduate Theses and Dissertations

Stream fishes on the Ozark Plateau have been influenced both by historic events (i.e. vicariance versus dispersal) and ecological forces (i.e. flow regime). To examine the role of these processes, genetic structure of Central Stoneroller (Campostoma anomalum), an ecologically important omnivorous minnow with a broad distribution and elevated abundance, was evaluated across populations in the White River drainage of the Ozark Plateau in Arkansas and Missouri. Fin clips of five to eight individuals were taken at each of 20 sites (N=138 individuals; average=6.9), selected so as to represent two different flow regimes: intermittently flashy (N=10 sites; N=73 individuals; average=7.3/ site) …

Alliaria Petiolata (M.Bieb.) Cavara & Grande [Brassicaceae], An Invasive Herb In The Southern Ozark Plateaus: A Comparison Of Species Composition And Richness, Soil Properties, And Earthworm Composition And Biomass In Invaded Versus Non-Invaded Sites, Jennifer D. Ogle

Graduate Theses and Dissertations

Invasive species are widely recognized as organisms that severely alter ecosystem processes in the habitats to which they are introduced. Alliaria petiolata is one of the most important invasive plants in forests of the northern United States. This study examined the geographic distribution of the plant in the southern Ozarks, as well as the effect that it may be having on natural processes within forests of the region by comparing plant species richness, plant cover, and soil properties in invaded and non-invaded plots. It was found that A. petiolata is not significantly altering species richness, cover, or soil properties in …

Monochamus Titillator Oviposition And Intraspecific Competition In Shortleaf Pine Bolts, Ryan Patrick Rastok

Graduate Theses and Dissertations

Monochamus titillator (Coleoptera: Cerambycidae) feed on trees in the family Pinaceae as adults and larvae. Adults feed on healthy twigs and branches and oviposit on stressed, dead, or dying trees. Prior to oviposition, females construct pits on the bark surface using their mandibles. The number of eggs laid beneath bark, where oviposition pits have been constructed, varies greatly. Developmental time and adult body size also vary greatly. I investigated oviposition and intraspecific competition with the goal of determining the degree to which various insect densities and oviposition times impact the following: 1) oviposition pit construction; 2) egg deposition; 3) emergence, …

Effects Of Water Column P-Availability And Litter Microbial Mediated Processes And Stoichiometry In Aquatic Systems, Ayla Smartt

Graduate Theses and Dissertations

Anthropogenic nutrient enrichment of aquatic ecosystems is prevalent and can have detrimental effects on biological condition. Many of these effects have been attributed directly or indirectly to changes in autotrophic processes. However, in detrital-based streams changes in course detrital stoichiometry and decomposition have been related to changes community structure and production at higher trophic levels highlighting the importance of considering the heterotrophic microbial responses to enrichment. Leaf litter stoichiometry, which is determined in part by the tree species source and the microbial communities that comprise the associated biofilm, is likely related to decomposition rates, but few studies examine these variables …

Applications Of A New Geodata Crawler For Landscape Ecology: From Mapping Natural Stream Hydrology To Monitoring Endangered Beetles, Douglas Ryan Leasure

Graduate Theses and Dissertations

An investigation of endangered American burying beetle (Nicrophorus americanus) ecology led to development of a Geodata Crawler with applications in eco-hydrology. Geodata Crawler includes a national GIS (geospatial information systems) database with layers that quantify climate, land cover, soils, human development, and other attributes of the biosphere. For user-locations in the continental United States, Geodata Crawler can rapidly tabulate site-specific statistics within automatically delineated sample areas: points, site radii, watersheds, and riparian zones, among others. Geodata Crawler supported a multi-scale analysis of N. americanus habitat at a military installation in western Arkansas to produce a Landsat-based monitoring tool. Royle's N-mixture …

Effects Of Large Scale Growing Season Prescribed Burns On Movement, Habitat Use, Productivity, And Survival Of Female Wild Turkey On The White Rock Ecosystem Restoration Project Of The Ozark-St. Francis National Forest, Henry Tyler Pittman

Graduate Theses and Dissertations

Restoration of woodland and savanna ecosystems has become a common management strategy in the Central Hardwoods region. Over the past two decades forest managers have implemented woodland and savanna restoration at the landscape level (≥10,000 ha), especially using early growing season prescribed fire. The implementation of the restoration strategy has coincided with declines of Eastern Wild Turkey (Meleagris gallopavo silvestris) in many treated areas causing concern that early growing season prescribed fire was impacting wild turkey. We initiated our study to examine the effect of woodland and savanna restoration on the ecology and habitat of wild turkey in the Ozark …

Habitat Assessment Of Two Narrowly Endemic Plant Species, Ozark Spiderwort (Tradescantia Ozarkana) E. S. Anderson And Woods. And Newton's Larkspur (Delphinium Newtonianum) D. M. Moore, Autumn Lynn Coffey Olsen

Graduate Theses and Dissertations

The threat of biodiversity loss is upon us with the onset of climate change and our ever-demanding needs of the Earth's resources for a rapidly growing human population. Species highly vulnerable to loss are those limited in abundance and distribution, or those with reduced genetic diversity. Efforts to actively conserve a sensitive species require effectual data on the probable causes of their vulnerability. Two species of concern, Delphinium newtonianum and Tradescantia ozarkana, are globally rare endemic vascular plant species found only in the Interior Highlands of North America. In an attempt to understand the causes for their endemism, habitat …

Small Mammal Community Associations And Habitat Use At Pea Ridge National Military Park, Benton County, Arkansas, Christopher Reddin

Graduate Theses and Dissertations

Juniperus virginiana L. (Eastern Red Cedar) is a fire-intolerant tree species that has been invading and altering grassland ecosystems throughout the American Great Plains and Midwest. To see how Eastern Red Cedar encroachment affects small mammal communities, we surveyed small mammals using mark-recapture methods in Eastern Red Cedar forest and 5 other habitats common to the Ozark region. Additionally, we compared the microhabitat use of presumed juniper obligate Peromyscus attwateri J.A. Allen (Texas Mouse) and its conspecific P. leucopus Rafinesque (White-Footed Mouse). We ran over 7000 trap-nights and found that the small mammal species composition in Eastern Red Cedar was …

Effects Of Petroleum Distillates On Amphibian Development, Kate Walker

Graduate Theses and Dissertations

Petroleum distillates are widely used as an energy source and the extraction and disposal of these chemicals are done with little consideration of their effects on aquatic environments. Amphibians are considered excellent ecological indicators but little research has examined effects of petroleum distillates on aquatic species. I evaluated the lethal and sublethal effects on larval amphibians with exposure to petroleum distillates associated with various venues of pollution including hydraulic fracturing. I selected three petroleum distillates (kerosene, oil, and unleaded gasoline) that are known to have negative effects on aquatic organisms and are similar to the common constituents of mixtures used …

Survival, Abundance, And Geographic Distribution Of Temperate-Nesting Canada Geese (Branta Canadensis) In Arkansas, Margaret Eliese Ronke

Graduate Theses and Dissertations

Temperate-nesting Canada geese in Arkansas have grown in abundance and range since reintroduction in the 1980s. The Arkansas Game and Fish Commission uses harvest and other methods to maintain the population at desired levels. However, continued management of temperate-nesting geese requires knowledge of the population's demographics and current range to help establish quantifiable management goals.

To assess the need and effect of changing hunting regulations, survival and recovery rates and abundance were estimated for this population. Annual survival rates of temperate-nesting Canada geese banded and recovered in Arkansas from 2005 to 2011 were estimated using the Burnham joint live-dead recovery …

Taxonomic And Seasonal Variation Among Extant Hyracoids Based On Dental Microwear Texture Analysis, Ann Marie Walcutt

Graduate Theses and Dissertations

A number of works have been published on habitats and diets of living hyraxes but much remains to be learned about the paleoenvironment contexts of the much larger, more dominant but now extinct forms of the order. Here, I analyze the dental microwear of modern hyraxes to assess dietary and ecological relationships among the four extant species of Procaviidae: Heterohyrax brucei, Procavia capensis, Dendrohyrax arboreus, and Dendrohyrax dorsalis. The purpose of this study was to establish an extant baseline series for the interpretation of microwear texture patterns, and inference of diets, of extinct members of the …

Relationships Between Landscape Factors And Crayfish Density And The Interacting Effects Of Grazing And Increased Sedimentation On Algal Biomass, Katheryn Haley Rose

Graduate Theses and Dissertations

In recent years in the United States there has been a rapid expansion in anthropogenic sources of sediment in streams including construction, agriculture, and drilling for natural gas. Potential effects land disturbance associated with activities from natural gas development on aquatic biota in surrounding streams have not yet been well documented. An increase in inorganic sediment in streams can be detrimental to organisms through a variety of mechanisms including alteration of dominant substrate type, higher turbidity resulting in lower visibility, and burial of food resources such as algae and detritus. Increasing sedimentation in stream environments through anthropogenic disturbance is a …

The Interactive Effects Of Multiple Stressors On Lithobates Catesbeianus And Anaxyrus Americanus, Matthew Kyle Holden

Graduate Theses and Dissertations

Amphibian populations worldwide have experienced dramatic declines, and many species have already become locally, regionally, or globally extirpated with thousands more being threatened with extinction. These declines have occurred more rapidly in amphibians than any other group of vertebrates, which is especially concerning to scientists because amphibians serve as indicator species of overall environmental health. Major causes for amphibian declines are discussed in Chapter 1 and include: habitat modification and destruction, commercial over-exploitation, introduced species, environmental contaminants, global climate change, and infectious diseases.

Chapter 2 discusses the major research aspects of the thesis by examining the interactive effects of multiple …

Ecology And Structure Of Black Bear (Ursus Americanus) Populations In The Interior Highlands Of Arkansas, Thea Vandervelde Kristensen

Graduate Theses and Dissertations

In the Interior Highlands of Arkansas, Missouri, and Oklahoma, over-harvest, extensive logging, and reductions of habitat availability by other means contributed to the decline of black bears (Ursus americanus). Bears were extirpated from the majority of the region by the 1940's Oklahoma by 1915 and from Missouri by 1931. From 1958-1968, the Arkansas Game and Fish Commission undertook a reintroduction to the Ouachita and the Ozark National Forests in Arkansas. The successful growth and expansion of the released population caused these efforts to be considered one of the most successful reintroductions of carnivores. In this dissertation, I sought to examine …

Ecology And Flock-Following Behavior Of The Wedge-Billed Woodcreeper In Eastern Ecuador, Abigail Darrah

Graduate Theses and Dissertations

The wedge-billed woodcreeper (Glyphorynchus spirurus) is a common understory suboscine passerine of lowland Neotropical rainforests. It frequently joins mixed-species understory flocks but also regularly forages alone, and thus is an excellent model species on which to conduct comparative behavioral observations to examine the hypothesized costs and benefits of flock-following. Individuals exhibit variable flocking propensities (proportion of time spent with flocks), and thus observing the correlations between flocking propensity and physical and environmental factors can provide further insight into the importance of flock-following to the ecology of this species. Despite its abundance at many sites and its wide geographic range, surprisingly …

Litter Conditioning Is Differentially Affected By Leaf Species, Phosphorus Enrichment, And Light Availability, Erin E. Scott

Graduate Theses and Dissertations

Anthropogenic enrichment of nitrogen and phosphorus is one of the most pervasive and detrimental threats to aquatic ecosystems worldwide. In streams that rely on allochthonous basal food resources, such as leaves, nutrient pollution can result in altered food quality and decreased carbon (C) standing stocks. However, the magnitude and mechanisms of this change in quality are poorly understood. Laboratory microcosm studies were conducted to 1) quantify the response of litter C:P to a gradient of phosphorus (P) enrichment (0, 0.05, and 0.5 mg SRP/L) across leaf species with variable levels of degradability (sugar maple and oak), and 2) quantify the …

Genetic Structure Of The Copperhead (Viperidae: Agkistrodon Contortrix Mokasen) At Its Most Northern Distribution, Brenna Aaren Levine

Graduate Theses and Dissertations

The focus of molecular studies in North American pitvipers has been on species that warrant conservation concern, such as Timber (Crotalus horridus) and Massasauga rattlesnakes (Sistrurus catenatus). Scant effort has been directed towards the molecular ecology of the Copperhead (Agkistrodon contortrix), other than to evaluate male reproduction in a laboratory setting and phylogenetic history. Thus, employing DNA-based molecular techniques to study the natural history of A. contortrix will broaden our knowledge of molecular ecology in North American pitvipers, and particularly in a non-threatened species that can serve as a surrogate for threatened and endangered …

Habitat Modeling Of Three Endemic Crayfish Species In The Black River Drainage Of Missouri And Arkansas: Factors Affecting Distribution And Abundance, Matthew Stephen Nolen

Graduate Theses and Dissertations

The Ozark faunal region of Missouri and Arkansas harbors a high level of aquatic biological diversity, especially in regards to endemic crayfish. Orconectes eupunctus, Orconectes marchandi, and Cambarus hubbsi are three such endemics that are threatened by a limited natural distribution and the invasions of Orconectes neglectus. I sought to determine how natural and anthropogenic factors influence these three species across multiple spatial scales. Local and landscape data were used in decision tree analyses (CART) to determine their influence effect on presence/absence and density of the three species. Predictive models were validated using k-fold cross validation. O. eupunctus presence was …

Phenotypic Plasticity Of Rattlesnake Trophic Morphology, Matthew Thomas Smith

Graduate Theses and Dissertations

The trophic morphology of gape-limited predators constrains the shape and size of prey items they can ingest. Trophic morphology consists of any morphological feature that is involved in the handling and ingestion of food. Diet has a profound effect on the morphology of many gape-limited predators. Identifying how prey type and resource level affect the morphology of different populations is an essential step in understanding the mechanisms contributing to patterns of morphological diversity. Species interactions (Chapter 1) induce plasticity in morphology that can lead to increased fitness, morphological divergence, and eventually speciation.

In Chapter 2, a laboratory study tested the …