Terrestrial and Aquatic Ecology Commons^™

Dynamics Of Baseline Stable Isotopes Within A Temperate Coastal Ecosystem: Relationships And Projections Using Physical And Biogeochemical Factors, Andrew Mackey

Theses: Doctorates and Masters

Measurements of carbon (13C/12C; δ13C) and nitrogen (15N/14N; δ15N) stable isotope ratios have become important tools for: estimating energy flow and trophic positions in aquatic foodwebs; comparing food webs; and aiding in the tracking of wide-ranging consumers. However, each of these applications requires accurate measurements of isotopic signatures in organisms at or near the base of the food web (e.g. autotrophs and their consumers), which act as basal reference points from which to calibrate inferences. Therefore, understanding variations in isotopic baselines, and the mechanisms leading to their variability, is crucial for food web ecology.

Using the shallow temperate reefs along …

An Economic Analysis Of High-Intensity, Short-Duration Grazing Systems In South Dakota And Nebraska, Bronc Mcmurtry

Electronic Theses and Dissertations

Four different grazing systems: two rotational, a continuous, and a high-intensity, short-duration (mob) system, replicated twice, were evaluated from an economic perspective. Mob grazing is defined as a system having very high stocking rates for a small amount of time. Livestock are forced to eat or trample the vegetation. Stocking rates and average daily gains (ADG) were collected from the UNL Barta Brothers ranch near Rose, Nebraska. The study started in 2011 and lasted until 2014. Using the performance data and other cost data relevant to South Dakota and Nebraska, budgets were set up for each system and extrapolated to …

Abundance, Density, And Opinions About Columbian Black-Tailed Deer, Whidbey Island, Washington, Robert P. Wingard

Graduate Student Theses, Dissertations, & Professional Papers

Obtaining reliable knowledge is the first step towards properly managing wildlife species. Columbian black-tailed deer (Odocoileus hemionus columbianus) on Whidbey Island, Washington have not been the subject of study, and little is known about the population, or the opinion of resident’s of Whidbey Island towards the deer population. However, wildlife managers suggest deer on the island may be overabundant or over social carrying capacity. Given the lack of empirical knowledge about the deer population or human opinions towards deer on Whidbey Island, I designed research to determine the abundance and density of Columbian black-tailed deer on Whidbey Island, …

Decadal Scale Responses Of Soil And Ecosystem Processes To Forest Restoration In Rocky Mountain Conifer Forests, Peter Ganzlin

Graduate Student Theses, Dissertations, & Professional Papers

Decades of fire suppression have left much of the forest in the intermountain western United States exceedingly dense, and forest restoration techniques – including thinning and prescribed fire – are increasingly being used in an attempt to mitigate the potentially disastrous effects of severe wildfire, to enhance tree growth and regeneration, and to stimulate soil nutrient cycling. While many of the short-term effects of forest restoration have been established, the long-term effects on soil biogeochemical and ecosystem processes are largely unknown. In this thesis I present two manuscripts documenting and synthesizing these long-term impacts. The first chapter focuses on the …

School Gardens: Cultivating A Child’S Nutritional Habits, Environmental Knowledge, And Sustainability Practices, Jeffrey Meltzer

Honors Theses

School gardens have existed since the late nineteenth century and today are becoming increasingly popular in many parts of the world, including where I studied in Maine and Australia (AUS). Multiple organizations support school gardens in Maine, including the Maine School Garden Network, which has over 125 registered school gardens. In AUS, the Stephanie Alexander Kitchen Garden Foundation primarily supports the school garden movement and has over 800 registered school gardens. While many researchers have studied school gardens, few have compared two countries, focused on environmental sustainability, or investigated Maine in particular. This thesis combines information from literature reviews, and …

Coarse Woody Debris And The Carbon Balance Of A Moderately Disturbed Forest, Amy V. Schmid

Theses and Dissertations

Landscapes are comprised of multiple ecosystems shaped by disturbances varying in severity and source. Moderate disturbance from weather, pathogens, insects, and age-related senescence, in contrast to severe disturbances that fell trees, may increase standing woody debris and alter the contribution of coarse woody debris (CWD) to total ecosystem respiration (R_E). However, woody debris dynamics are rarely examined following moderate disturbances that substantially increase standing dead wood stocks. We used an experimental manipulation of moderate disturbance in an upper Great Lakes forest to: 1) examine decadal changes in CWD stocks through a moderate disturbance; 2) quantify in situ CWD …

Evolution, Systematics & Geographic Parthenogenesis Of Ilyodromus (Crustacea, Ostracoda), Rylan James Shearn

Theses

Most multicellular organisms reproduce sexually at some point in their life cycle. This is paradoxical because being asexual is theoretically far more advantageous. Asexual organisms do not need to find and court new mates, they reproduce at a faster rate, and with no males, all members of the population contribute toward population growth rate. With over 20, often mutually exclusive hypotheses, this paradox resists a synthesised explanation, and continues to represent one of the largest gaps in our understanding of fundamental evolutionary theory. Clearly, more real world studies are required that document the selective mechanisms underlying differences in evolutionary fitness …

Plant Functional Traits Of Dominant Native And Invasive Species In Mediterranean-Climate Ecosystems, Jennifer L. Funk, Rachel J. Standish, William D. Stock, Fernando Valladares

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The idea that dominant invasive plant species outperform neighboring native species through higher rates of carbon assimilation and growth is supported by several analyses of global datasets. However, theory suggests that native and invasive species occurring in low-resource environments will be functionally similar, as environmental factors restrict the range of observed physiological and morphological trait values. We measured resource-use traits in native and invasive plant species across eight diverse vegetation communities distributed throughout the five Mediterranean-climate regions, which are drought-prone and increasingly threatened by human activities including the introduction of exotic species. Traits differed strongly across the five regions. In …

Toxic Cyanobacteria Aerosols: Tests Of Filters For Cells, Sean R. Perry, Alexis Mack, James F. Haney, Amanda Murby

Honors Theses and Capstones

Aerosolization of toxic cyanobacteria released from the surface of lakes is a new area of study that could uncover a previously unknown route of exposure to toxic cyanobacteria. Since toxic cyanobacteria may be responsible for adverse human health effects, methods and equipment need to be tested and established for monitoring these airborne bacteria. The primary focus of this study was to create controlled laboratory experiments that simulate natural lake aerosol production. I set out to test for the best type of filter to collect and analyze the aerosolized cells as small as 0.2-2.0 µm, known as picoplankton. To collect these …

Re-Envisioning Community-Wildfire Relations In The U.S. West As Adaptive Governance, Jesse B. Abrams, Melanie Knapp, Travis B. Paveglio, Autumn Ellison, Cassandra Moseley, Max Nielsen-Pincus, Matthew S. Carroll

Environmental Science and Management Faculty Publications and Presentations

Prompted by a series of increasingly destructive, expensive, and highly visible wildfire crises in human communities across the globe, a robust body of scholarship has emerged to theorize, conceptualize, and measure community-level resilience to wildfires. To date, however, insufficient consideration has been given to wildfire resilience as a process of adaptive governance mediated by institutions at multiple scales. Here we explore the possibilities for addressing this gap through an analysis of wildfire resilience among wildland-urban interface communities in the western region of the United States. We re-engage important but overlooked components of social-ecological system resilience by situating rural communities within …

Ecohydraulic Investigation Of Diatoms In A Bedrock-Controlled Stream, Alex M. Rittle

Theses and Dissertations--Geography

Recent studies within the past decade or so have shown the importance of algae in geomorphic and hydrologic processes of lotic systems. However, the ecohydraulic role of algae in bedrock systems has largely been ignored. In addition, the utility of algae as indicators of channel dynamics have often been assumed by geomorphologists, but relatively few studies have examined this relationship. The purpose of this study was to determine whether algae, specifically diatoms, are useful indicators of channel geomorphological dynamics, and to examine if distinct habitats or biotopes typical in fluviokarst and bedrock systems provide unique habitat space for diatoms, and …

Striking The Balance: Challenges And Perspectives For The Protected Areas Network In Northeastern European Russia, Svetlana V. Degteva, Vasily I. Ponomarev, Sasha W. Eisenman, Vyacheslav Dushenkov

Publications and Research

Increasing anthropogenic pressure on the largest remaining tracts of old-growth boreal forest in Europe necessitates additional conservation of ecosystems and biodiversity in northeastern European Russia. In a regional network comprising 8 % of the Nenets Autonomous District and 13.5 % of the Komi Republic, 248 areas have varying protected statuses as state nature reserves (zapovedniks), national parks, reserves/sanctuaries (zakazniks), or natural monuments. Due to increased natural resource extraction in this relatively pristine area, designation of additional protected areas is critical for the protection of key ecological sites. The history of ecological preservation in these regions is herein described, and recent …

An Investigation Into The Occurrence Of Batrachochytrium Dendrobatidis Infection In Plethodontid Salamander Communities Of Robinson Forest, Sarah H. Spaulding

Theses and Dissertations--Forestry and Natural Resources

Environmental and anthropogenic stressors negatively affect amphibians in a variety of ways, often increasing their vulnerability to pathogen infection and mortality. Sampling for the pathogenic fungus Batrachochytrium dendrobatidis (Bd) was conducted in order to: 1) determine the presence of chytrid infection in stream-associated plethodontid salamanders of southeastern Kentucky, and 2) evaluate differences in infection intensity between salamanders residing in intact forest streams, timber-harvested streams, and surface-mined streams. During 14 sampling sessions occurring between March, April and May of 2013, DNA samples from 306 individual salamanders within 8 species from the family Plethodontidae were collected; additional amphibians (i.e. frogs, newts) were …

Scales Of Resilience: Community Stability, Population Dynamics, And Molecular Ecology Of Brook Trout In A Riverscape After A Large Flood, Erin V. Rodgers

Antioch University Dissertations & Theses

Climate change in the northeastern United States currently and in future decadal predictions is characterized by warmer average temperatures and more frequent and intense storm events. Many aquatic organisms that thrive below a certain temperature threshold, such as brook trout, are being pushed towards their upper thermal limits, ultimately lowering their probability of survival and resilience to disturbance. In late-August and early-September 2011, Hurricane Irene and Tropical Storm Lee created an extended flood in the Delaware Water Gap region of Pennsylvania and New Jersey, as well as much of the northeast. This dissertation examines the effects of this flood on …

Recovery Potential Of The Mussel Communities In The Lower Section Of Big Walnut Creek, Jared B. Ellenbogen

Undergraduate Honors Thesis Projects

Since the enactment of the 1977 Clean Water Act, biologists have created numerous multimetric assessment tools to evaluate the biological integrity of water resources, using biological criteria. The integrity of Big Walnut Creek, Ohio, has been in flux since the 1955 construction of Hoover Dam, and while current water quality is high, mussel communities in the creek have yet to recover to historical levels. This study sought to determine the cause of the decline in the mussels in the lower section of the creek below the dam. Historical creek data, including a fish-based index of biotic integrity (f-IBI), invertebrate community …

Nutrient Competition Between Algae And Juncus Effusus In The Lake Fayetteville Artificial Spiral Wetland, Toryn Jones, Thad Scott

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

There is insufficient research focusing exclusively on how nutrient competition between algae and wetland macrophytes affects the growth of these species. This study examined the relationship between nutrient concentrations (N and P), algal concentrations, and the growth of Juncus effusus. Juncus effusus growth in the Lake Fayetteville artificial spiral wetland was monitored over a four month period during the prime growing season. Eighteen plants were taken from the wetland and replanted in 1 of 6 treatments: plant-only, algae-only, combined, plant-only +supplement, algaeonly +supplement, or combined +supplement. The algae and combined environments received an inoculation of algae, and the +supplement treatments …

Use Of Airborne Digital Imagery To Examine Floodplain Complexity At Varying Discharges, Katelyn P. Driscoll

Graduate Student Theses, Dissertations, & Professional Papers

Floodplains are composed of aquatic and terrestrial habitats that are frequently reshaped by hydrologic processes operating at various spatial and temporal scales. I hypothesized that floodplain habitat complexity is maximized at intermediate discharges because small changes in flow result in substantial aquatic habitat changes and extreme discharges are associated with a decreased habitat heterogeneity. Between April and September 2014, I collected ultra-high resolution digital multispectral imagery of the Clark Fork River, Montana taken on 6 dates between early spring and fall. Following image mosaicking into a single image, unsupervised classification of the spectral reflectance was used to identify and quantify …

A Gis Assessment Of Ecoregion Representation In Chile's Existing And Proposed Integrated Network Of Protected Areas, Jessica Schutz

Graduate Student Theses, Dissertations, & Professional Papers

Chile's state designated protected areas are reported to show representation bias and to be unable to meet conservation goals. Private protected areas are considered an important tool to resolve these issues, which has led to support for increasing the role of private protected areas in Chile and creating an integrated public-private protected area network. But the validity of the capacity of private protected areas to fix Chile's state protected area network bias, and the advantage of creating an integrated protected area network, have not been assessed. This study uses the most recent data on Chile's state, private, and international protected …

Assessing The Contributions Of Two Stocked Strains On A Minnesota-Wisconsin Border Water, Douglas Zentner

Journal of Earth and Life Science

Stocking has long been used as a management tool in the United States even though many of its effects remain cryptic. Past comparisons between stocked strains were generally based on the survival and growth rates of physically marked individuals. More recently the use of genetic markers to assess contributions of stocked individuals has been employed by fisheries managers. Using 13 microsatellite markers we assessed the contributions of two muskellunge (Esox masquinongy) strains (Wisconsin and Leech) stocked into the St. Louis River Estuary. Ancestry in the adult samples remained relatively constant with differences only observed between the 2008 and …

Using Wild I.D. As A Reliable Source For Mark And Recapture Studies On Northern Pike (Esox Lucius), Martin Evans

Journal of Earth and Life Science

Mark and recapture studies are a very popular method fisheries biologists use to assess certain fish populations in lakes. This process can be very labor intensive and expensive. Wild I.D. is free software developed by Dartmouth College that uses SIFT program to find unique features in photographs. Initially developed for identification of African land mammals the program gives each photo a score and percent match to other photos. Northern pike were used in this study to determine if the program can recognize simulated recapture events. Photos of sample fish were taken at two separate locations, the photos were then copied …