Ecology and Evolutionary Biology Commons^™

The Influence Of Diet Composition, Plant Defensive Chemicals, And Winter Severity On The Nutritional Condition Of A Freeranging, Generalist Herbivore, Grace L. Parikh

Dissertations, Master's Theses and Master's Reports - Open

Herbivory requires animals to manage intake of toxic phytochemicals. Detoxification and excretion of these chemicals prevents toxicity, but is energetically expensive. I investigated the relationship between investment in detoxification and nutritional condition for moose on Isle Royale National Park (Alces alces) during winter, using urinary indices from urine samples collected in snow. The ratio of urinary urea nitrogen:creatinine is an indicator of nutritional condition, and the ratio of glucuronic acid:creatinine is an indicator of investment in detoxification. Nutritional condition declined with greater investment in detoxification. An alternative means of managing defensive chemical intake is to diversify the diet. Microhistological …

Interactive Effects Of Climate Change And Fungal Communities On The Decomposition Of Wood-Derived Carbon In Forest Soils, Samantha L. Mosier

Dissertations, Master's Theses and Master's Reports - Open

Soils are the largest sinks of carbon in terrestrial ecosystems. Soil organic carbon is important for ecosystem balance as it supplies plants with nutrients, maintains soil structure, and helps control the exchange of CO₂ with the atmosphere. The processes in which wood carbon is stabilized and destabilized in forest soils is still not understood completely. This study attempts to measure early wood decomposition by different fungal communities (inoculation with pure colonies of brown or white rot, or the original microbial community) under various interacting treatments: wood quality (wood from +CO₂, +CO₂+O₃, or ambient …

Climate Anomalies And Primary Production In Lake Superior, Marcel L. Dijkstra

Dissertations, Master's Theses and Master's Reports - Open

This dissertation supports the modeling of primary production in Lake Superior by offering site specific kinetics and algorithms developed from lab experiments performed on the natural phytoplankton assemblage of Lake Superior. Functions, developed for temperature, light and nutrient conditions and the maximum specific rate of primary production, were incorporated in a 1D specific primary production model and confirmed to published in-situ measured rates of primary production.

An extensive data set (supporting model calibration and confirmation), with a fine spatiotemporal resolution, was developed from field measurements taken bi-weekly during the sampling seasons of 2011, 2012 and 2014; considered to be meteorologically …

Ecophysiological Responses Of Sugar Maple Roots To Climatic Conditions, Mickey Philip Jarvi

Dissertations, Master's Theses and Master's Reports - Open

The severity of future climate change resulting from anthropogenic alteration of the global C cycle will depend in part on feedbacks between atmospheric greenhouse gases and forest ecosystem carbon balance, but how these two systems will interact is not entirely understood. Forests are both major sinks and sources for atmospheric CO₂ through the processes of photosynthesis and ecosystem respiration. The balance between these two processes could be altered if autotrophic respiration were to increase exponentially with temperature as climate warms. Root respiration, and especially fineroot respiration (<1 mm diameter), is a major contributor to total ecosystem C exchange. A study to assess long-term responses of root respiration to warmer soil conditions was conducted at the SMART (sugar maple altered rainfall and temperature) experiment located in Alberta, MI at the Michigan Technological University’s Ford Center and Forest. It was found that acclimation of fine-root respiration in this system was not due to an insufficient supply of carbohydrates from photosynthesis (substrate limitation), but was the result of adenylate control. As a result, fine root respiration was constrained to levels needed to perform work required of the fine roots (e.g. nutrient acquisition). Acclimation also occurred for roots 1-2 mm in diameter at the 0-10 cm soil depth, but not in any roots larger than 2 mm or in roots of any size at deeper soil depths. As a result, at the ecosystem level, total root system respiration was 60% greater in warmed soil than in unwarmed soil. The studies in experimentally warmed sugar maple forests were complemented by an examination of fine-root respiration and root biomass at sixteen sugar maple forests located across a latitudinal gradient across sugar maple’s native range, spanning approximately 10°C of mean annual temperature. Sugar maple in the southern, warmer sites had lower root N, lower specific fine-root respiration at a given temperature, and less fine-root biomass than that from the northern cooler regions. Fine root respiration at ambient soil temperature actually decreased from north to south, despite a nearly 10°C increase in soil temperature. However, within sites respiration measured across three sample dates did increase with temperature. The next big question is whether these adjustments that exist across sugar maple’s range are plastic responses to l local climate or result from genotypic differences among populations in different locations. If the former is true, all sugar maple would be capable of acclimation, reduction in root biomass, and/or reduction in root N as mechanisms for dealing with climatic warming, and sugar maple would have a large capacity to adjust to future climate change. The latter would suggest that predicted rates of climatic warming could have negative impacts on this important species across its entire current range. The lack of changes in fine root biomass and root N concentration at the SMART study location after four plus years of soil warming support the possibility that differences along the latitudinal transect are largely the result of inherent genetic differences among population.

Movement Of Bigmouth Sleeper, Gobiomorus Dormitor, In The Río Cañas, Puerto Rico, Revealed By Radio Telemetry, And A Discussion Of The Species’ Amphidromous Characterization, Steve E. Lochmann, Christine Adelsberger, J. Wesley Neal

Gulf and Caribbean Research

Bigmouth Sleeper, Gobiomorus dormitor, are tropical fish native to rivers of Puerto Rico. They are popular sport fish targeted by local anglers. They are considered as diadromous, but this characterization is controversial. The displacement of Bigmouth Sleepers in the Río Cañas, Puerto Rico, was examined using radio telemetry. Twenty fish were radio-tagged and monitored from January to November 2008. Fish were in the Río Cañas 69%, 62%, and 59% of the time before (January-May), during (June-August), and after (September-November) the spawning season, respectively. Average detected linear home range (within the river) for all tracking periods was 2.3 km, but …

Impact Of Development On Freshwater Turtle Populations Of Coastal South Carolina: An Examination Of Land Use And Road Density, Andre Dominguez

Electronic Theses and Dissertations

Previous studies (Haxon 2000; Steen and Gibbs 2004; Marchand and Litvaitis 2004; Aresco 2005) have demonstrated that urbanization and development have disproportionally adverse affects on female turtles. In order to test this paradigm I caught 301 turtles (primarily Trachemys scripta scripta) in ten ponds (5 impacted and 5 unimpacted) across coastal South Carolina. Not only do coastal South Carolina turtles not follow the same male biased pattern of many other studies, there was an overall female bias (154:95). Turtle metrics were between the types of sites existed as well, indicating larger/older population of turtles in unimpacted sites. Water quality parameters …

Tide-Dependent Predation Patterns Of Piscivorous Fishes In Shallow Estuarine Creeks, Matthew Ross Helms

Electronic Theses and Dissertations

The distribution and foraging behavior of predatory salt marsh fishes is shaped by the movements of prey, many of whom seek shelter in shallow and tributary creeks. I hypothesized that the distribution of piscivorous fishes in marsh creek channels would differ with proximity to the mouths of intertidal creeks and with tidal stage. Custom-built trotlines baited with live minnows were deployed during four discrete tidal stages at two microhabitats in main creek channels: (1) adjacent to intertidal creek mouths, and (2) along straight banks in North Inlet estuary, South Carolina. Catch-per-unit-effort of predatory fishes was significantly higher (Wilcoxon signed-rank tests, …

Sun-Compass Orientation During Natal Dispersal In Hatchling Blanding's Turtles (Emydoidea Blandingii), Meredith Anne Schlenner

All Graduate Theses, Dissertations, and Other Capstone Projects

Blanding's turtle hatchlings emerge from their natal nests naïve to environmental stimuli and primarily sense visual cues on the horizon as a dispersal target. During a period of hours or days, hatchlings develop a compass mechanism that allows them to maintain a direction of travel, even when the target is not visible. We examined the dispersal directions of Blanding's turtle hatchlings captured during dispersal by translocating them into a circular arena in a field of corn in order to measure their dispersal direction guided by a compass mechanism. To test for use of a sun compass, a magnetic compass, or …

Climate-Adjusted Provenancing: A Strategy For Climate-Resilient Ecological Restoration, Suzanne M. Prober, Margaret Byrne, Elizabeth H. Mclean, Dorothy A. Steane, Brad M. Potts, Rene E. Vaillancourt, William D. Stock

Research outputs 2014 to 2021

Investments in ecological restoration are estimated at $US 2 trillion per annum worldwide and are increasing rapidly (Cunningham, 2008; Williams et al., 2014). These investments are occurring in an environment of accelerated climate change that is projected to continue into the next century, yet they currently take little account of such change. This has significant implications for the long-term success of restoration plantings across millions of hectares, with germplasm used in current restoration efforts potentially poorly-adapted to future climates. New approaches that optimize the climate-resilience of these restoration efforts are thus essential (Breed et al., 2013; Williams et al., 2014; …

The Next Generation Of Action Ecology: Novel Approaches Towards Global Ecological Research, R. L. White, A. E. Sutton, R. Salguero-Gómez, T. C. Bray, H. Campbell, E. Cieraad, N. Geekiyanage, L. Gherardi, A. C. Hughes, P. Søgaard Jørgensen, T. Poisot, Lucía Desoto, Naupaka B. Zimmerman

Biology Faculty Publications

Advances in the acquisition and dissemination of knowledge over the last decade have dramatically reshaped the way that ecological research is conducted. The advent of large, technology-based resources such as iNaturalist, Genbank, or the Global Biodiversity Information Facility (GBIF) allow ecologists to work at spatio-temporal scales previously unimaginable. This has generated a new approach in ecological research: one that relies on large datasets and rapid synthesis for theory testing and development, and findings that provide specific recommendations to policymakers and managers. This new approach has been termed action ecology, and here we aim to expand on earlier definitions to …

Ecology Postdocs In Academia: Primary Concerns And Possible Solutions, A. K. Shaw, D. E. Stanton, S. R. Supp, A. Budden, S. Eby, P. L. Reynolds, R. Salguero-Gómez, D. R. Scholes, Naupaka B. Zimmerman

Biology Faculty Publications

No abstract provided.

Connecting People And Ideas From Around The World: Global Innovation Platforms For Next-Generation Ecology And Beyond, P. Søgaard Jørgensen, F. Barraquand, V. Bonhomme, T. J. Curran, E. Cieraad, T. G. Ezard, L. Gherardi, R. A. Hayes, T. Poisot, R. Salguero-Gómez, Lucía Desoto, B. Swartz, J. M. Talbot, B. Wee, Naupaka B. Zimmerman

Biology Faculty Publications

We present a case for using Global Community Innovation Platforms (GCIPs), an approach to improve innovation and knowledge exchange in international scientific communities through a common and open online infrastructure. We highlight the value of GCIPs by focusing on recent efforts targeting the ecological sciences, where GCIPs are of high relevance given the urgent need for interdisciplinary, geographical, and cross-sector collaboration to cope with growing challenges to the environment as well as the scientific community itself. Amidst the emergence of new international institutions, organizations, and meetings, GCIPs provide a stable international infrastructure for rapid and long-term coordination that can be …

An Assessment Of The Role Of Roads In Population Demography And Genetic Structuring In Two Species Of Lizards In The Northern Chihuahuan Desert, Kevin Floyd

Open Access Theses & Dissertations

Roads can fragment habitat and increase mortality rates of wildlife, potentially reducing population sizes and gene flow, which in turn can reduce genetic diversity through genetic drift. Although negative road impacts have been found in a variety of taxa, not all species are impacted. For instance, species that move less and rarely encounter roads and those that avoid the roads are predicted to not be negatively affected. Yet tests of these predictions are uncommon, especially for reptiles and particularly lizards. Side-blotched lizards (Uta stansburiana) are small sit-and-wait predators, while the larger marbled whiptails (Aspidoscelis marmorata) are active foragers. Their responses …

Introduction Effort, Climate Matching And Species Traits As Predictors Of Global Establishment Success In Non-Native Reptiles, Peter J. Mahoney, Karen H. Beard, Andrew M. Durso, Aimee G. Tallian, Arin Lexine Long, Ryan J. Kindermann, Nicole E. Nolan, Daniel Kinka, Harrison E. Mohn

Biology Faculty Publications

Non-native reptiles are often detrimental to native communities and ecosystems and can be extremely difficult to manage once established. Thus, there is considerable interest in predicting the likelihood of establishment of nonnative reptiles. We assessed three hypotheses describing possible factors contributing to the successful establishment of introduced reptiles in an effort to better identify potential invaders.

Stable Isotope Values Delineate The Non-Breeding Distributions Of Sooty Shearwaters Puffinus Griseus In The North Pacific Ocean, David Thompson, Leigh Torres, Graeme Taylor, Matt Rayner, Paul Sagar, Scott A. Shaffer, Richard Phillips, Sarah Bury

Faculty Publications, Biological Sciences

Following breeding, sooty shearwaters Puffinus griseus leave New Zealand waters and migrate to 1 of 3 distinct areas in the North Pacific Ocean, effectively exploiting environmental resources across a large proportion of this northern ocean basin. In this study, we combined electronic tracking technology with stable isotope analyses (δ15N and δ13C) of feathers grown during the non-breeding period in order to evaluate whether isotope signatures can be used to identify specific non-breeding areas used by sooty shearwaters. A region to the east of Japan was utilised by the majority of tracked birds, whereas others used areas off the west coast …

Approximation Of Fire-Return Intervals With Point Samples In The Southern Range Of The Coast Redwood Forest, California, Usa, Gregory Jones, Will Russell

Faculty Publications, Environmental Studies

A legacy of past fires is evident in the form of blackened basal hollows found throughout the southern range of the coast redwood (Sequoia sempervirens [D. Don] Endl.) forest.  A deeper look reveals cambial scars dating back centuries, telling a story of low- to moderate-intensity fires that burned periodically across California’s Central Coast bioregion.  While attempts have been made to reconstruct the fire history of this forest type, estimates of the fire-return interval vary widely, and the relationship of the fire-return interval to varying cultural influences is not fully understood.  We analyzed 373 fire scars from 70 cross-sections removed from …

Anthropogenic Litter And Microplastic In Urban Streams: Abundance, Source, And Fate, Amanda Rae Mccormick

Master's Theses

The accumulation and ecological effects of anthropogenic litter (AL) and microplastic are well-documented in marine ecosystems, but these materials’ abundances in rivers is unknown. AL enters rivers from recreation, runoff, and illegal dumping. Microplastic fibers and pellets are abundant in wastewater treatment plant (WWTP) effluent which enters rivers. Our objectives were to: (1) quantify AL abundance and composition in urban streams, (2) measure AL flux, accumulation, and export, and (3) measure riverine microplastic concentration and analyze its bacterial communities. We collected AL from 5 urban streams and observed greater AL density in riparian habitats and greater mass in benthic habitats. …

Horseshoe Crab Research In Urban Estuaries: Challenges And Opportunities, Jennifer Mattei, Mark L. Botton, Mark Beekey, Christina P. ColóN

Biology Faculty Publications

Horseshoe crabs rely on estuaries for food resources, places to spawn and for larvae and juveniles to develop and grow. Many of these estuaries are becoming increasingly urbanized and dominated by human activity. An urban estuary is characterized by armored shorelines, high nutrient loads, large fluctuations in algal and bacteria populations, increased levels of pollutants like heavy metals and pesticides, and seasonally low oxygen levels and pH. While urban estuaries are challenging for horseshoe crab survival and to researchers trying to study them, there are also opportunities for involving the public in research and increasing public awareness of the importance …

The Mismanagement Of Limulus Polyphemus In Long Island Sound, U.S.A.: What Are The Characteristics Of A Population In Decline?, Mark Beekey, Jennifer Mattei

Biology Faculty Publications

Over the past 15 years, horseshoe crabs in Connecticut have gone from being considered a nuisance species to a species of Greatest Conservation Need in 2015. This has happened through first, its discovery as an economically important species, second through research of its ecological role in coastal estuaries, and third, through education of the public concerning its role in the environment and their own health. To manage horseshoe crab populations successfully requires long term monitoring, research and education. The use of annual or biannual trawl data trends to assess the success of management decisions is limited due to the high …

Physical And Biological Constraints On The Abundance Of Cyanobacteria In The James River Estuary, Brendan C. Trache

Theses and Dissertations

The tidal-fresh James River experiences recurring blooms of toxin-producing cyanobacteria, including Microcystis aeruginosa. However, cyanobacteria cell densities in the James are relatively low. Our purpose was to identify key factors suppressing cyanobacteria growth in the face of eutrophication. A mesocosm experiment was designed to test the effects of light, mixing and grazing on cyanobacteria abundance, with nutrients held constant. We predicted that toxic cyanobacteria would be most abundant under stagnant conditions, with enhanced light, with no bivalve grazers present. Abundances of indicator gene copies and phytoplankton counts supported this hypothesis. However, chlorophyll-a, phycocyanin, and the toxin microcystin were all …

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 …

Carnivore Diet Identification Through Scat And Genetic Analysis In Namibia, Africa, Alicia J. Walsh

Honors Theses and Capstones

Worldwide the cheetah population is declining making them Africa’s most endangered large cat. Namibia, Africa currently has the largest population of cheetahs in the world. During the summer of 2014, I did scat analysis of carnivores on the property of the Cheetah Conservation Fund (CCF) in Namibia in order to better understand the predators that compete with the cheetah and how the ecosystem works as a whole. I worked at CCF for nine weeks to analyze the diets of carnivores in the area through genetic and scat analysis. Analyzing carnivore feces would ultimately identify the diet of various carnivores in …

Iron Deficiency Increases Growth And Nitrogen-Fixation Rates Of Phosphorus-Deficient Marine Cyanobacteria, Nathan S. Garcia, Feixue Fu, Peter N. Sedwick, David A. Hutchins

OES Faculty Publications

Marine dinitrogen (N²)-fixing cyanobacteria have large impacts on global biogeochemistry as they fix carbon dioxide (CO₂) and fertilize oligotrophic ocean waters with new nitrogen. Iron (Fe) and phosphorus (P) are the two most important limiting nutrients for marine biological N₂ fixation, and their availabilities vary between major ocean basins and regions. A long-standing question concerns the ability of two globally dominant N₂-fixing cyanobacteria, unicellular Crocosphaera and filamentous Trichodesmium, to maintain relatively high N₂-fixation rates in these regimes where both Fe and P are typically scarce. We show that under P-deficient …

Living On The Margin In The Anthropocene: Engagement Arenas For Sustainability Research And Action At The Ocean-Land Interface, B. C. Glavovic, K. Limburg, K-K. Liu, K-C. Emeis, H. Thomas, H. Kremer, B. Avril, J. Zhang, M. R. Mulholland, M. Glaser, D. P. Swaney

OES Faculty Publications

The advent of the Anthropocene underscores the need to develop and implement transformative governance strategies that safeguard the Earth's life-support systems, most critically at the ocean-land interface - the Margin. The seaward realm of the Margin is the new frontier for resource exploitation and colonization to meet the needs of coastal nations and humanity overall. Here, we spotlight the pivotal role of the Margin for planetary resilience and sustainability, highlight priority issues, and outline a research strategy which aims to: (a) better understand Margin social-ecological systems; (b) guide sustainable development of Margin resources; (c) design governance regimes to reverse unsustainable …

Heterotrophic And Autotrophic Contribution To Dinitrogen Fixation In The Gulf Of Aqaba, Eyal Rahav, Barak Herut, Margaret R. Mulholland, Natalia Belkin, Hila Elifantz, Ilana Berman-Frank

OES Faculty Publications

We evaluated the seasonal contribution of heterotrophic and autotrophic diazotrophy to the total dinitrogen (N₂) fixation in the photic zone of a pelagic station in the northern Gulf of Aqaba, Red Sea. N₂ fixation rates were highest during a Trichodesmium bloom in winter (0.7 nmol N l^-1 d^-1), decreased 7-fold 1 wk later throughout the upper 200 m (~0.1 nmol N l^-1) d^-1), and were significantly coupled with both primary and bacterial productivity. N₂ fixation rates were generally higher in the upper 200 m (~0.4 nmol N l^{-1 …}

New Tracer To Estimate Community Predation Rates Of Phagotrophic Protists, Alexander B. Bochdansky, Melissa A. Clouse

OES Faculty Publications

Predation of eukaryotic microbes on prokaryotes is one of the most important trophic interactions on Earth, representing a major mortality term and shaping morphology and composition of prokaryotic communities. Here we introduce and validate a new tracer to determine predation rates on prokaryotes. Minicells of Escherichia coli marked with a bright green fluorescent protein (GFP) vector have many operational advantages over previously used prey analogs such as fluorescently labeled bacteria. GFP-minicells are similar in size to naturally occurring bacteria from a variety of environments including the oligotrophic open ocean and the deep sea. They are relatively stable against microbial and …

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 …

Ramapough/Ford The Impact And Survival Of An Indigenous Community In The Shadow Of Ford Motor Company’S Toxic Legacy, Chuck Stead

Antioch University Dissertations & Theses

The purpose of this study was to examine the history of the Ford Motor Company’s impact upon the Ramapo Watershed of New York and New Jersey, as well as upon the Ramapough Munsi Nation, an indigenous population living there. In a 25 year span the automaker produced a record number of vehicles and dumped a massive amount of lead paint, leaving behind a toxic legacy that continues to plaque the area and its residents. The Ramapough people are not unlike many native nations living in the United States who have experienced industrial excess. This study examines the mindset that allows …

Matrix And Edge Effects On The Maintenance Of Ecological Function In An Afromontane Protected Area, Robin M. Martino

Antioch University Dissertations & Theses

Land use type in the human dominated matrix surrounding tropical forest can influence edge effects at the forest-matrix interface. Edge effects can alter ecological processes and impact the function of forest edge ecosystems. A key ecological process that helps maintain tropical forest and is affected by forest disturbance is seed dispersal by large, fruit eating vertebrates (frugivores). This dissertation examines how the type of vegetation in the matrix, the `soft’ edge contrast of pine plantations and the `hard’ edge contrast of tea plantations, affect seed dispersal behavior of large frugivores, and the structure and composition of tree species, in forest …

Helping To Resolve Taxonomic Conflicts Within The Genus Amblyomma (Acari:Ixodidae) From A Molecular Perspective, Paula Lado

College of Graduate Studies: Theses & Dissertations

This work sought to reassess the taxonomic status of Amblyomma parvum Aragao, 1908 and of the A. maculatum group of ticks Camicas, 1998. By using different molecular markers, 12SrDNA, 16SrDNA, DL, COI, COII (mitochondrial) and ITS2 (nuclear), I analyzed the systematic relationships between these taxa and their closest relatives. Phylogenetic analyses by maximum parsimony, maximum likelihood, and Bayesian analysis were performed in order to determine relationships among species and populations, and to determine the evolutionary history of these ixodids. The data obtained supported the hypothesis of cryptic speciation occurring within A. parvum, with the northern populations of Central America being …