Physical Sciences and Mathematics Commons^™

Spline Modeling And Localized Mutual Information Monitoring Of Pairwise Associations In Animal Movement, Andrew Benjamin Whetten

Theses and Dissertations

to a new era of remote sensing and geospatial analysis. In environmental science and conservation ecology, biotelemetric data recorded is often high-dimensional, spatially and/or temporally, and functional in nature, meaning that there is an underlying continuity to the biological process of interest. GPS-tracking of animal movement is commonly characterized by irregular time-recording of animal position, and the movement relationships between animals are prone to sudden change. In this dissertation, I propose a spline modeling approach for exploring interactions and time-dependent correlation between the movement of apex predators exhibiting territorial and territory-sharing behavior. A measure of localized mutual information (LMI) is …

Transport And Fate Of Phosphorus In The Nearshore Zone Of Lake Michigan, Nathan Van Ee

Theses and Dissertations

Bioavailable phosphorus loads exported to Lake Michigan from the Milwaukee and Sheboygan River Watersheds appear to have increased in the last 40 years despite meeting total phosphorus (TP) loading goals set by the Great Lakes Water Quality Agreement (GLWQA).Overall, bioavailability of P delivered from the Milwaukee and Sheboygan Rivers was highest during the warmer months, which coincides with the nearshore nuisance algae growth season. However, first order loss rates of SRP calculated during baseflow recession were also greatest during the summer, suggesting that increased river residence time during the summer could reduce export of bioavailable P. Observations of phosphorus partitioning …

Autumn Tree Phenology In Northern Wisconsin: Humans Versus Photographs, Trevor Iglinski

Theses and Dissertations

Ecosystem primary productivity halts when plants go dormant, and so the timing of dormancy as it relates to autumn phenology has been a focus of much interdisciplinary research. While monitoring plant phenology has its roots in directly observing specimens, digital sensors along with modern methods have also become a mainstay in phenology. Results from different methods often vary, so there is still a need to better understand how digital cameras record autumn phenology, especially in comparison with ground-based observations (Keenan et al. 2014). This study compared autumn phenology derived from direct ground observations with upward-facing fisheye photography, in the context …

An Investigation Into The Trophic Magnification Of Polychlorinated Biphenyls In The Lake Michigan Food Web, Philip Hurst

Theses and Dissertations

Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants known to contribute to several adverse health conditions in humans including cancers and a suite of liver diseases. While there exist 209 unique PCB congeners, the World Health Organization has identified 12 that pose the greatest health risk to humans due to these congeners’ functional similarity to dioxins, another notoriously toxic class of contaminants. Along with methylmercury, PCBs are the primary drivers behind fish consumption advisories in the Great Lakes. These guidelines are informed primarily by surveys of contaminants in freshwater biota. However, the proliferation of invasive species, such as …

Seasonal Offshore/Inshore Migration Of Round Gobies, Erik Carlson

Theses and Dissertations

Since the invasion of round gobies (Neogobius melanostomus) in Lake Michigan, they have become integrated into both the nearshore and offshore food webs. Round gobies can be found in shallower water (<20 m) during the summer, but they disappear from these depths in early fall. They have been collected, occasionally, offshore in depths greater than 70 m during fall and early spring. These observations and other anecdotal evidence indicate that round goby migrate offshore during the fall and return in the spring. To study this, a large remotely operated vehicle (ROV) was used to conduct video transects offshore at various depths. The offshore sampling showed that round gobies migrated away from nearshore habitat in early October and were almost exclusively found deeper than 20 m by November. The round gobies remained offshore (>30 m) until mid-May, when they began the return to nearshore habitat. The cues to start the offshore and return migrations were not the focus of this project, but the fall offshore migrations coincided with decreasing temperatures nearshore in the fall, and in spring, the offshore movement of the thermal bar. The offshore migration in fall provide an increase in forage opportunity for deep, cold-water predators such as …

Unraveling Plague Ecology Through Vector And Host Genetics, Rachael Marie Giglio

Theses and Dissertations

The transmission of vector-borne diseases involves complex interactions between vectors and their host species. These complex host-parasite interactions can be difficult to study with traditional, field-based methods. My dissertation aims to use a population genomics approach to elucidate transmission pathways of plague among prairie dog colonies. Plague is a flea-borne, zoonotic disease caused by the bacterium Yersinia pestis. It is infamous for causing the Black Death (1347-1353), one of the most devastating pandemics in human history. Since its emergence in North America around 1900, plague has spread to native rodents, thus creating a sylvatic cycle. Prairie dogs (Cynomys spp.) are …

Incorporation, Morphology, And Extinction Of Framework-Building Metazoans In Early Cambrian Reef Ecosystems From The Western Usa And Mongolia And Their Effects On Reef Diversity, David Russell Cordie

Theses and Dissertations

The early Cambrian represents an important transition in the evolution of life, perhaps most vividly exemplified by reef ecosystems as they changed from microbial-supported to metazoan-supported framework reefs. Microbial reefs were initially composed of Renalcis- and Epiphyton-group calcifying microbes. Subsequent reefs began to incorporate archaeocyathan sponges within this framework. This represents a shift in the source of carbonate production, which can be quantified using thin section point counts. In archaeocyathan reefs from the western USA, carbonate contribution from metazoan framework builders increased from zero to 29.7%. Similar reefs from Mongolia increased from zero to 5.0%. Increases in Laurentian archaeocyath contributions …

River Bank Inducement Influence On A Shallow Groundwater Microbial Community And Its Effects On Aquifer Reactivity, Natalie June Gayner

Theses and Dissertations

Placing groundwater wells next to riverbanks to draw in surface water, known as riverbank inducement (RBI), is common and proposed as a promising and sustainable practice for municipal and public water production across the globe. However, these systems require further investigation to determine risks associated with river infiltration especially with rivers containing wastewater treatment plant (WWTP) effluent. Since microbes drive biogeochemical transformations in groundwater and largely affect water quality, it is important to understand how the microbial communities in drinking water wells are affected by river infiltration. This study investigated if, and to what extent, the microbial community in a …

Invertebrate Paleoecology Of High Paleo-Latitude Carboniferous Strata Of The Tepuel-Genoa Basin, Argentina, Kate M. Gigstad

Theses and Dissertations

The Late Paleozoic Ice Age (LPIA), which began in the latest Devonian and ended in the Late Permian, was a time of active environmental changes. During this time, glaciers waxed and waned over the ancient continent of Gondwana that was situated over the southern pole. This time of transition from icehouse to greenhouse in the Permian is our closest analogue to our current environmental conditions and increased knowledge of our planetary past will greatly influence our future. Much of the previous research on marine invertebrate paleoecology during the LPIA occurs in far-field or low paleolatitude localities, but less is known …

A Hemimysis Driven Novel Ecosystem At A Modified Boulder Breakwall, Eric John Geisthardt

Theses and Dissertations

The US Army Corps of Engineers (USACE) is mandated to maintain and repair aging breakwall structures in all commercial ports on the Great Lakes. In May of 2014, the construction of Milwaukee Harbor USACE “green” breakwall (GBW) reconciliation created complex rocky aquatic habitat by depositing cobble-sized stone as a veneer over standard 6-10 ton boulders, thus creating “control” (boulder) and “treatment” (cobble) habitats. The breakwall is home to a prolific population of Hemimysis anomala, the introduced Ponto-Caspian mysid, which is significantly more abundant on cobble versus boulders (p<0.05, using a novel trap for Hemimysis). Fish and forage communities were sampled in 2015 and 2016 using a combination of experimental and micromesh gill nets, night scuba diving surveys, and a novel Hemimysis trap. This nearshore lithophilic mysid appears to provide a significant new seasonal food resource in the Milwaukee Harbor for pelagic prey fishes during inshore spawning migrations and upwelling events. Alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) fed heavily on Hemimysis with some individuals consuming hundreds of mysids. Night scuba diving surveys and gill netting confirmed that rainbow smelt preferred to forage on the cobble section (p<0.05), and also consumed more Hemimysis there than they did at the control breakwall site (p<0.05). Hemimysis were also the primary food item consumed by nearshore game fishes such as YOY yellow perch (Perca flavescens), YOY largemouth bass (Micropterus salmoides), and juvenile rock bass (Ambloplites rupestris) caught at the breakwall. This study provides the first documented evidence that where abundant in the Laurentian Great Lakes, Hemimysis do have the ability to significantly impact local food webs and drive the feeding ecology of both pelagic transient and nearshore resident fishes.

Late Paleo-Indian Period Lithic Economies, Mobility, And Group Organization In Wisconsin, Ethan Adam Epstein

Theses and Dissertations

The following dissertation focuses upon the organization of Pleistocene / Holocene period lithic technology in Wisconsin circa 10,000 – 10,500 years before present. Lithic debitage and flaked stone tools from the Plainview/Agate Basin components of the Heyrman I site (47DR381), the Dalles site (47IA374), and the Kelly North Tract site at Carcajou Point (47JE02) comprise the data set. These Wisconsin sites are located within a post glacial Great Lakes dune environment, an inland drainage/riverine environment, and an inland wetland/lacustrine environment. An assemblage approach is used to examine the structure of each site’s lithic economy. This broad approach to lithic organization …

Are We Missing The Forest For The Trees? Quantifying The Maintenance Of Diversity In Temperate Deciduous Forests, Kathryn Barry

Theses and Dissertations

One of the most pressing questions of community ecology is: Why do we have so many species? Over 100 hypotheses have been proposed to answer this question for woody plants over the past 70 years, yet there remains no consensus among community ecologists. In this dissertation, I explore the evidence supporting several different hypotheses (Chapter 1). I provide evidence that negative density dependence, where individuals perform poorly near members of their own species, may only be relevant for canopy tree species (Chapter 2). Understory species do not demonstrate negative density dependence while canopy trees demonstrate negative density dependence that increases …

Functional Diversity Of Regional Marine Paleocommunities After The Permo-Triassic Mass Extinction: Case Studies From Panthalassa And Paleo-Tethys, Ashley Ann Dineen

Theses and Dissertations

The Permo-Triassic mass extinction (PTME) was the largest biodiversity collapse in Earth’s history. Published data has been interpreted as indicating that marine ecological devastation following the PTME was protracted and may have lasted 5 million years into the Middle Triassic (Anisian). However, a review of previous literature shows that understanding of biotic recovery is usually based on only a few components of the ecosystem, such as on taxonomic diversity, a single genus/phylum, or shallow water facies. Typically, paleocommunities are considered fully recovered when dominance and diversity are regained and normal ecosystem functioning has resumed. However, to more fully characterize Triassic …

Paleoecology Of Glacial And Non Glacial Carboniferous Faunas During The Late Paleozoic Ice Age In Patagonia, Nicole Braun

Theses and Dissertations

The Late Paleozoic Ice Age (LPIA) records the only icehouse to greenhouse transition in Earth’s history that involved complex marine and terrestrial life and serves as an analogue for Quaternary climate change. Identifying biotic responses to paleoenvironmental variations during the LPIA is important in order to understand how our modern fauna may respond to contemporary climate change. Low-paleolatitude (far-field) marine faunas far from ice centers have been recognized and used as a global proxy for biotic responses to the LPIA, but the biotic responses in high-paleolatitude (near-field) regions close to Gondwanan ice centers have received much less attention. We tested …

Paleoredox Geochemistry And Bioturbation Levels Of The Exceptionally Preserved Early Cambrian Indian Springs Biota, Poleta Formation, Nevada, Usa, Jonah Meron Novek

Theses and Dissertations

The early Cambrian Indian Springs biota, western Nevada, USA exhibits Burgess Shale-type (BST) preservation of a diverse array of animal phyla, including the earliest definitive echinoderms. It therefore provides an important window on animal life during the Cambrian radiation. The objective of this study is to analyze the trace metal paleoredox geochemistry and bioturbation levels of this BST deposit in order to characterize the paleoenvironmental conditions in which these animals lived and their fossils were preserved. A total of 28 rock samples were collected from outcrops at three previously reported intervals of exceptional preservation at the Indian Springs locality, as …

Microbially Induced Sedimentary Structures As An Ecological Niche In Subtidal Early Triassic Environments Of Eastern Panthalassa, Erin Wimer

Theses and Dissertations

Early Triassic microbially induced sedimentary structures (MISS) are a critical link in understanding the dynamics between changing environmental conditions and their effect on marine communities. The Permo-Triassic mass extinction (PTME) resulted in vacated ecospace and reduced bioturbation that allowed MISS to expand into Early Triassic subtidal environments. Data from southern Idaho and Montana indicate that MISS inhabited and proliferated in subtidal marine environments during the Griesbachian. This propagation led to changes in shallow substrate geochemical conditions that directly affected macrofaunal communities. The proliferation of microbial mats would have created anoxic and euxinic porewaters and made vertical bioturbation physiologically difficult. Geochemical …

Phosphorus Recycling By Profunda Quagga Mussels In Lake Michigan, Caroline Mosley

Theses and Dissertations

Quagga mussels (Dreissena rostiformis bugensis) act as ecosystem engineers in the southern basin of Lake Michigan, altering physical habitats and biogeochemical processes. Adapted to cold and oligotrophic conditions, profunda quagga mussels thrive on the soft substrate of deeper depths. At a 55 m site (10,000 mussels m-2) offshore from Milwaukee, WI, profunda mussel biomass (g m-2) was 1/3 of biomass (g m-2) measured at a 10 m comparison site (5,000 mussels m-2). Higher densities but less biomass is due to profunda mussels having less tissue for a given length and the population per m2 comprising of mostly small mussels ( …

Early Triassic Echinoids Of The Western United States: Their Implications For Paleoecology And The Habitable Zone Hypothesis Following The Permo-Triassic Mass Extinction, Jenna Rolle

Theses and Dissertations

Confronted with global climate change and ocean acidification, our collective knowledge of ecosystem response during times of environmental crisis in Earth's ancient past may provide insights towards combating ecological degradation in modern oceans. Early Triassic marine environments were characterized by oceanic warming due in part to elevated levels of atmospheric CO₂ and periodic intervals of localized anoxia, resulting in an overall restructuring of faunal dominance, distribution, and biodiversity. Re-assembly of ecological communities during the Early Triassic are largely unknown; however, a previous paleoecological study by Tyler Beatty et al. (2008), suggests that post-extinction recovery length was minimized in shallow …

Plankton Trophic Structure Within Lake Michigan As Revealed By Stable Carbon And Nitrogen Isotopes, Zachery G. Driscoll

Theses and Dissertations

Zooplankton represent a critical component of aquatic food webs in that they transfer energy from primary producers to higher trophic positions. However, their small size makes the application of traditional trophic ecology techniques difficult. Fortunately, novel techniques have been developed that can be used to elucidate feeding information between zooplankton species. I used the analysis of stable carbon and nitrogen isotope ratios to estimate the trophic structure of Lake Michigan's zooplankton community. The major zooplankton species, three size classes of seston, and seston from specific water column depths were collected in 2011 and 2012 for stable isotope analysis. Trophic position …

Sedimentology And Paleoecology Of Fossil-Bearing, High-Latitude Marine And Glacially Influenced Deposits In The Tepuel Basin, Patagonia, Argentina, Kathryn N. Pauls

Theses and Dissertations

The glacial and non-glacial intervals of the Late Paleozoic Ice Age (LPIA) are of great interest because they are our best deep time analogue for Pleistocene climate change. The changes and adaptations of the biota, as seen in the rock record, can serve as a proxy for understanding future trends in Earth's climate system. Most of the known LPIA marine faunal data come from low-latitudinal regions, and thus have been used as a global proxy. However, modern organisms in the low-latitudes (far-field basins) respond differently to a changing climate relative to marine organisms in the polar regions (near-field basins). In …

Impacts Of Spatial, Environmental, And Compositional Differences On Community-Level Flowering Phenology, Isaac William Park

Theses and Dissertations

This dissertation investigates three important topics related to flowering phenology throughout the United States. First, this work evaluates the utility of herbarium records for estimating historical variation in community-level flowering phenology, and evaluate the relationship of such estimates to satellite-derived greenup timing at regional scales. This dissertation then reconstructs historical variations in flowering phenology throughout the spring, summer, and autumn across South Carolina for the years 1951 through 2009. These estimates will then be compared to seasonal temperature variations throughout this period. Finally, this dissertation develops novel herbarium-based methods to separate intraspecific phenological variations over space from changes in flowering …

The Shifting Importance Of Competition And Facilitation Along Diversity, Environmental Severity, And Plant Ontogenetic Gradients, Alexandra Wright

Theses and Dissertations

Ecological theory and empirical studies have focused heavily on the importance of competition in plant communities. Competition can help explain species coexistence, the maintenance of species diversity, and biological invasions. Competition for resources appears to be ubiquitous among coexisting organisms. This overwhelming focus on competition over the past one hundred years may have overshadowed the importance of positive interactions (facilitation). Growing near your neighbors involves competition for resources, but it also involves alteration of a shared microclimate. Neighboring plants have the capacity to increase shade, decrease air temperatures, increase humidity, and increase shallow soil moisture in their local environment. In …

Complexity And Uncertainty In Human And Ecological Risk Assessment, Matthew Jordan Dellinger

Theses and Dissertations

Multiple interacting stressors in the environment present increasingly complex risks to human health. Too often, however, the data required for traditional risk assessment are either lacking or unavailable at the necessary spatial or temporal scale. In addition, assessment practices and management policies need to move away from single factor approaches in order to accommodate the reality of complex chemical mixtures and environmental stressors. Recent literature suggests that a paradigm shift is under way. This points to a need for the development of new techniques both for rapid data collection and flexible risk assessment strategies that can adapt to make use …

Air-Water Gas Exchange And The Carbon Cycle Of Green Bay, Lake Michigan, James Waples

Theses and Dissertations

The purpose of this study was to constrain estimates of the kinetics of gas transfer across the air-water interface as well as quantify the net flux of carbon between southern Green Bay (1635 km²) and the atmosphere.

In 1994 and 1995, over 3500 measurements of surface water CH₄ and CO₂ were made using a continuous sample disk equilibrator. Estimates of CH₄ flux from southern Green Bay to the atmosphere based on air-water concentration gradients, shear corrected wind speeds and the U/K (wind speed/transfer coefficient) relationship of Broecker et al. (1978) agreed to within ~10% of …