Ecology and Evolutionary Biology Commons^™

Untangling The Biological Contributions To Soil Stability In Semiarid Shrublands, V. Bala Chaudhary, Matthew A. Bowker, Thomas E. O'Dell, James B. Grace, Andrea E. Redman, Mathias C. Rillig, Nancy C. Johnson

School of Environmental Sustainability: Faculty Publications and Other Works

Communities of plants, biological soil crusts (BSCs), and arbuscular mycorrhizal (AM) fungi are known to influence soil stability individually, but their relative contributions, interactions, and combined effects are not well understood, particularly in arid and semiarid ecosystems. In a landscape-scale field study we quantified plant, BSC, and AM fungal communities at 216 locations along a gradient of soil stability levels in southern Utah, USA. We used multivariate modeling to examine the relative influences of plants, BSCs, and AM fungi on surface and subsurface stability in a semiarid shrubland landscape. Models were found to be congruent with the data and explained …

Soil Nutrient Changes Following A Typha X Glauca Invasion In A Great Lakes Coastal Wetland, Lane Marie Vail

Master's Theses

Invasive species are one of the major threats to the integrity and health of Great Lakes coastal wetlands. Plant invaders, such as the hybrid cattail Typha x glauca, threaten wetlands, as they can cause shifts in ecosystem structure and function and modify biogeochemical cycles and nutrient availability. Cheboygan Marsh on the coast of Lake Huron is currently undergoing invasion by T. x glauca, and soils in T. x glauca-dominated areas of the marsh have greater soil carbon and nitrogen concentrations than in areas dominated by native vegetation. This study investigated whether T. x glauca is affecting the accumulation of carbon …

Horseshoe Crab Spawning Survey Protocol, Jennifer Mattei

Biology Faculty Publications

The protocol lists supplies and clothing needed for the survey, as well as which data is to be collected and when and how it should be entered for the census of horseshoe crabs on the Recapture Data Sheet for 2009. Adopted from Cape Cod and Delaware Bay survey protocols.

The Game Of Conservation: International Treaties To Protect The World’S Migratory Animals, Mark Cioc

Ohio University Press Open Access Books

The Game of Conservation is a brilliantly crafted and highly readable examination of nature protection around the world.

Twentieth-century nature conservation treaties often originated as attempts to regulate the pace of killing rather than as attempts to protect animal habitat. Some were prompted by major breakthroughs in firearm techniques, such as the invention of the elephant gun and grenade harpoons, but agricultural development was at least as important as hunting regulations in determining the fate of migratory species. The treaties had many defects, yet they also served the goal of conservation to good effect, often saving key species from complete …

Toward A More Wholly Communion: Cultivating Ecological Enlightenment And Sustainable Action In Christians, Cary Hauptman Gaunt

Antioch University Dissertations & Theses

Increasingly, environmental, scientific, and religious organizations and leaders are calling for people of faith to wake up to the global climate and other environmental crises and step up their ecological responsibility by leading more sustainable lives. Yet only a few seem to hear the calls and even fewer are responding in substantive ways. Many have commented on the gap between the religious theory for environmental care and the actual practice of living ecologically sustainable lives. Exploring how to bridge this gap is increasingly important as environmental regulatory, policy, and technology efforts fall short of goals and environmental professionals, including regulators, …

Seeing Shifts: Ecologists' Lived Experiences Of Climate Change In Mountains Of The American West, Kimberly Ford Langmaid

Antioch University Dissertations & Theses

This study explores the lived experiences of field ecologists who research the effects of global climate change on mountain species and ecosystems in the American West. The purpose is to generate narrative descriptions of ecologists’ experiences in order to communicate about both the scientific ecology and human ecology of climate change. Twenty prominent field ecologists participated in this study. Interviews with ecologists were transcribed and analyzed using a hermeneutic phenomenological methodology. Eight experiential themes emerged through the process of data analysis, and these themes provide the structure for presenting narratives of ecologists’ experiences. The eight themes are: thinking ecologically, the …

Dispersion Of Large-Seeded Tree Species By Two Forest Primates: Primate Seed Handling, Microhabitat Variability, And Post-Dispersal Seed Fate, Nicole D. Gross-Camp

Antioch University Dissertations & Theses

I describe the relative effectiveness of two primates in dispersing large-seeded tree seeds (> 0.5 cm) in the Nyungwe National Park (NNP), Rwanda. My objectives are three-fold: (1) to describe the relative effectiveness of primates in dispersing the seeds of five large-seeded tree species, (2) to evaluate the influence of primate seed-handling method on seed fate, and (3) to determine the influence of deposition site on seed fate. I employed focal tree observations, day-follows of habituated primate groups, in situ monitoring of primate-dispersed seeds, and experimental plots to achieve these objectives. Data were collected over the course of one year …

Peptide Hydrolysis And The Uptake Of Dipeptides By Phytoplankton, Margaret R. Mulholland, Cindy Lee

OES Faculty Publications

Rates of peptide hydrolysis (using the fluorescent substrate, lucifer yellow anhydride-labeled tetra-alanine) and dipeptide uptake (using dually labeled, ¹⁵N and ¹³C, dialanine) were measured in phytoplankton cultures and in natural populations during algal blooms dominated by one or two taxa. During most sampling events, both peptide hydrolysis and dipeptide uptake were greatest in the size fraction containing the dominant phytoplankter, suggesting that phytoplankton contribute substantially to or may even dominate observed extracellular peptide hydrolysis and dipeptide uptake in the environment. These are the first data suggesting that dipeptides may be taken up directly by phytoplankton and this may …

Ecology And Molecular Phylogenetics Of Hydnora (Hydnoraceae) In Southern Africa, Jay Francis Bolin

Biological Sciences Theses & Dissertations

The Hydnoraceae are a clade of root holoparasitic angiosperms that contain two small genera, Hydnora and Prosopanche. This study, focused on Hydnora, presents novel data regarding the pollination biology, germination ecology, parasite-host nutritional relationships, and the molecular systematics of this group. Experimental addition of the primary pollinator, Dermestes maculatus to Hydnora africana chamber flowers demonstrated beetle imprisonment during the carpellate stage. Changes in the inner surfaces of the androecial chamber allowed beetle escape after pollen release. Most beetles escaped, dusted with viable pollen, three days after pollen release. To investigate germination ecology, aqueous root extracts of host and …

Tidal Influences On Bacterial And Phytoplankton Abundances And The Resulting Effects On Patterns Of Dissolved Oxygen In The Skidaway River Estuary, Casey Colleen Brazell

College of Graduate Studies: Theses & Dissertations

Two studies were conducted to investigate the physical and biological processes contributing to the dissolved oxygen (DO) availability in the Skidaway River Estuary (SRE), Savannah, GA during the summer of 2005. A temporal study looked at changes in DO concentrations, Chlorophyll a concentrations, bacterial abundance, water depth, and salinity, every hour, for 26 hours, over both a neap and a spring tide. A spatial study looked at changes in the above variables at 5 sites along the SRE while following the tide inland during a neap high and low tide, and a spring high and low tide. DO concentrations varied …

Effects Of Habitat Quality On Reproduction In Two Georgia Populations Of Gopherus Polyphemus, Jaqueline W. Entz

College of Graduate Studies: Theses & Dissertations

Author's Abstract: The purpose of this study was to examine differences in maternal investment by examining variation in the habitat structure and reproductive parameters for two populations of Gopherus polyphemus in Southeast GA. Both habitat structure and reproductive parameters for these populations are known from a previous study, thus this study expands upon the previous one and addresses four main questions. (1) Has habitat quality changed in the past ten years within and between population sites? (2) Could a change of habitat have affected female morphology or female reproductive parameters within or between populations? (3) Is female body size shaping …

Ecology Of Neotropical Arboreal Snakes And Behavior Of New World Mollusk-Eating Snakes, Julie M. Ray

Biological Sciences Theses & Dissertations

The Neotropics is a biologically diverse region that provides man opportunities for ecological and behavioral studies. I utilized the speciose ophidian fauna of central Panama to explore the general ecology of arboreal snakes, the defensive behaviors of the snake community, and the diet of mollusk-eating snakes. I studied arboreal species to understand interspecilic relationships in several morphometric characters and to examine preferences in habitat. There were significant morphometric differences in relative length of jaw, mass, tail length, and size at midbody. The arboreal realm was partitioned among species by distance to ground, distance to water, and diameter of the perch. …

What's Up With Fiddler Crabs: Does Larval Dispersal Render Genetic Similarity In The Disjunct Distribution Of Uca Minax (Uca: Ocypodidae)?, Alexa Warwick

Honors Program Theses

The red-jointed fiddler crab, Uca minax, has a disjunct distribution along the Atlantic and Gulf coasts in North America. Previous studies have not found any significant discrepancies in morphology, physiology, or allozymes between the two groups of U.minax. The primary objective of this study was to use DNA sequence data to test whether genetic variation is consistent with patterns of morphological, physiological, and allozyme variation of the disjunct populations. We collected mitochondrial cytochrome oxidase subunit I and nuclear internal transcribed spacer sequences from approximately 100 individuals distributed across the range. Phylogenetic analyses of the haplotypes revealed no genetic differentiation …

Effects Of Plant Uptake And Micro-Topography On Chloride Transport In Arid Soils, Wenming Nie

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chloride concentration profiles to depths of 1 m were evaluated on a young alluvial fan in Eldorado Valley, NV. It was found that chloride beneath plant canopies were 11 to 222 times higher than adjacent (1 - 2 m away) bare soil locations. Two-dimensional numerical simulations using HYDRUS 2D/3D model were used to further explore the impact of plants on chloride transport. The simulation results indicated that lateral flow driven by root uptake concentrated chloride toward root zones, leading to the accumulation of chloride under plant canopies. Results also suggest that locally micro-topography can have a substantial impact on chloride …

Factors Associated With Duck Use Of Impounded And Natural Wetlands In Western South Dakota, Jane E. Austin, Deborah A. Buhl

The Prairie Naturalist

Many wetlands in the northern Great Plains west of the Missouri River are stock ponds, created by impoundment of natural drainages or excavation of existing wetlands to provide water for livestock or improve habitat for waterfowl. We evaluated factors influencing use of wetlands by breeding duck pairs and broods relative to modification, water regime, size, and hydrological location on United States Forest Service lands within the Grand River National Grassland in northern South Dakota (2003 and 2004). Responses for both indicated pairs and broods were related positively to wet area, total wetland area within 4 km, emergent edge cover, and …

Wolf, Canis Lupus, Visits To White-Tailed Deer, Odocoileus Virginianus, Summer Ranges: Optimal Foraging?, Dominic J. Demma, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

We tested whether Wolf (Canis lupus) visits to individual female White-tailed Deer (Odocoileus virginianus) summer ranges during 2003 and 2004 in northeastern Minnesota were in accord with optimal-foraging theory. Using GPS collars with 10- to 30-minute location attempts on four Wolves and five female deer, plus eleven VHF-collared female deer in the Wolves’ territory, provided new insights into the frequency of Wolf visits to summer ranges of female deer. Wolves made a mean 0.055 visits/day to summer ranges of deer three years and older, significantly more than their 0.032 mean visits/day to ranges of two-year-old deer, …

Predatory Senescence In Ageing Wolves, Daniel R. Macnulty, Douglas W. Smith, John A. Vucetich, L. David Mech, Craig Packer

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of …

Problems With The Claim Of Ecotype And Taxon Status Of The Wolf In The Great Lakes Region, Matthew A. Cronin, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Koblmuller et al. (2009) analyzed molecular genetic data of the wolf in the Great Lakes (GL) region of the USA and concluded that the animal was a unique ecotype of grey wolf and that genetic data supported the population as a discrete wolf taxon. However, some of the literature that the researchers used to support their position actually did not, and additional confusion arises from indefinite use of terminology. Herein, we discuss the problems with designation of a wolf population as a taxon or ecotype without proper definition and assessment of criteria.

Koblmuller et al. (2009) wrote ‘The GL …

Integrated Responses Of Crustaceans Inhabiting Estuaries To The Challenges Of Feeding And Digestion In Low Salinity, Daniel Luke Curtis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Estuaries are highly productive and serve as vital habitats for numerous decapod crustacean species. However, the environmental conditions within estuaries are often highly dynamic and subject to large changes in salinity and temperature that occur on seasonal and tidal scales. Not all of the species occupying these habitats are adept in coping with changes in these environmental conditions. This dissertation describes the influence of low salinity conditions on the 1) habitat preference, 2) feeding behaviour and 3) digestive physiology of crustaceans inhabiting estuaries. I have primarily focussed on a weak osmoregulator, the Dungeness crab, Cancer magister , but have also …

Molecular Systematics And Phylogeography Of The Genus Richardsonius, Derek Dee Houston

UNLV Theses, Dissertations, Professional Papers, and Capstones

The complex geological and climatic events that significantly altered the landscape throughout the Cenozoic Era impacted the diversification of many North American taxa, including freshwater fishes. Here, I employ an array of phylogenetic analyses using a multiple gene tree approach to address several questions regarding the phylogenetic relationships of the North American cyprinid genus Richardsonius and two other closely related genera, Clinostomus and Iotichthys. I also use divergence time estimates generated using fossil calibrations to qualitatively assess the phylogeographic implications of evolution within and among these three genera. Mitochondrial and nuclear DNA sequences show a sister relationship between Iotichthys and …

The Distribution Of Unpaired During Drosophila Oogenesis, Travis Sexton

University of Kentucky Doctoral Dissertations

Janus Kinase (JAK) activity specifies the cell fates of the follicular epithelium during Drosophila oogenesis by establishing a gradient of JAK activity with highest levels at the A/P poles. Unpaired (Upd), a ligand for the pathway, is expressed and secreted exclusively from the polar cells potentially establishing the JAK activity gradient. This project proposed that Upd acts as a morphogen to directly establish the JAK activity gradient, specifying the fates of the follicular epithelium. The aims of this work were to investigate the extracellular distribution of Upd and, in addition, factors that may be involved. Furthermore, upd3, a gene …

Vegetation Response To Restoration Treatments In A Former Pine Plantation In North Florida, Ryan C. Meyer

UNF Graduate Theses and Dissertations

As the human population in Florida continues to expand, development follows, and tree farms give way to homes and businesses. As parks are established, restoration of these semi-natural plantations may provide critical habitat for species conservation. This study evaluates vegetation response to restoration treatments at two study sites, formerly tree farms, now preserves in NE Florida. Treatments included thinning, clearing, or control (no treatment) within 10m^2 plots. Thinning reduced tree canopy to 20% (2-3 pines/plot) and removed all other vegetation; clearing treatments removed all biomass to bare soil; no herbicides were used. Within these plots richness and abundance was assessed …