Life Sciences Commons^™

Biological Soil Crusts In A Northeastern Pine Barren: Composition And Ecological Effects, Jessica Gilbert

Honors Theses

Biological soil crusts (BSCs), otherwise known as cryptogamic soil crusts, biocrusts, or cyanobacterial crusts, are soil aggregations hosting diverse biotic communities. They are composed of cyanobacteria and algae, and generally have a covering of moss and/or lichen. BSCs are typically found in arid to semi-arid regions throughout the world, and are integral soil stabilizers, moisture retainers, and nitrogen fixers in these communities. Along with these factors, BSCs are able to impact germination and establishment of plants, either as an accompanying influence, or direct result of those listed above. BSCs have yet to be formally described in the inland northeastern United …

Functions Of Ecosystems: Stream Metabolism As An Efficient And Effective Means To Gage The Health And Understand The Interworking Of Urban Streams In A Watershed Of Rock Island, Il, Ryan Johnson, Dr. Kevin Geedey

Celebration of Learning

Stream metabolism is a critical functional measure of stream health that integrates physical parameters like slope and discharge, with ecosystem functions like photosynthesis and respiration. Stream metabolism is widely studied; however, urban stream metabolism remains poorly understood. Stream metabolism was measured for five streams ranging from 1^st to 5^th orders from October 11^th to October 18^th 2017 and four streams ranging from 1^st to 4^th order from October 22^nd to 25^th 2017 located within an approximately 9.3 square kilometer watershed of Rock Island, IL that has an urban to suburban type of …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

The Distribution, Abundance, And Gut Microbiome Of Ribbed Mussel, Geukensia Demissa, Across Natural And Restored Salt Marshes In Jamaica Bay, New York, Bethany Freynk

Student Theses and Dissertations

Coastal wetlands perform valuable functions by protecting shorelines from floodwaters and storm surges, providing habitats for marine species, and improving local water quality. Unfortunately, over half of the area of global wetlands has been lost over the past century. Locally, in Jamaica Bay (Queens, NY), loss of wetlands has exceeded 98%. Restoration of Jamaica Bay marshes began in 2003. Ribbed mussels, Geukensia demissa, live symbiotically with marsh plants and have been shown to stabilize sediments and provide organic nutrients that enhance marsh plant growth. Mussels are suspension feeders, which collect algae from seawater and deposit organic matter in marsh sediments. …

Secrets Of A Rare Bird: Breeding Behavior Of The Gray-Breasted Flycatcher (Lathrotriccus Griseipectus) In Ecuador, William Harris Kirkpatrick

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

The Tumbesian region of southwestern Ecuador and northwestern Peru is home to a large number of endemic bird species. Many of these species are threatened with extinction, and little is known about their basic biology. Thus, information regarding natural history of species in the region is needed to guide conservation management. We studied the reproductive biology of the Gray-breasted Flycatcher, Lathrotriccus griseipectus, a small Tyrannid that lives in the Tumbesian region. Due to habitat destruction, the range size of L. griseipectus has dwindled and the species is now listed as Vulnerable on the IUCN Red List. We used a mounted …

Larval-Ant Interactions In The Mojave Desert: Communication Brings Us Together, Alicia Mellor

UNLV Theses, Dissertations, Professional Papers, and Capstones

Butterflies are a diverse and essential group of pollinators whose abundance is predominantly determined by growth and survival of their larvae. In the family Lycaenidae, many species participate in a larval-ant mutualism where ants feed on nutrient-rich nectar produced by larvae and, in turn, protect those larvae from predators. Emerging evidence indicates larval scent in the form of cuticular hydrocarbons (CHCs), not nectar production, drives this interaction. This study takes two approaches to investigate CHCs as the driver behind the larval-ant mutualism in three butterfly species native to southern Nevada: Euphilotes bernardino martini (Martin’s blue), Brephidium exilis (western pygmy blue), …

Marine-Derived Nutrient Cycling In The St. Croix River, Maine, Betsy Barber

Electronic Theses and Dissertations

Anadromous species can boost freshwater productivity through nutrient subsidies. Along the Maine coast of the northeast United States, several alewife populations are recovering after freshwater connectivity is restored. Iteroparity in this part of their range may reduce their role as nutrient subsidies. Stable isotope analysis was used to detect marine-derived nutrient input. Spatial and temporal trends were characterized in the St. Croix as a baseline before alewife recovery, and nutrient-diffusing substrates indicated nutrient co-limitation. A reference watershed was used to compare nutrient dynamics when alewives were present versus absent. Results indicated isotope shifts within particular functional feeding groups, but not …

Changes In Soil Microbial Functioning In Coastal Wetlands Exposed To Environmental Stressors And Subsidies, Shelby M. Servais

FIU Electronic Theses and Dissertations

Environmental perturbations are ubiquitous features of ecosystems and shape ecological structure and function. Climate change will alter the intensity and frequency of disturbances and expose ecosystems to novel combinations of useful inputs (subsidies) and harmful inputs (stressors). Coastal wetlands are particularly vulnerable to changing environmental conditions and are increasingly exposed to effects of interacting subsidies and stressors. In particular, the Florida Coastal Everglades, which has experienced accelerated change due to a history of water management practices, is vulnerable to new disturbances associated with climate change. The low-lying Florida Everglades faces multiple disturbances from storm surge, nutrient enrichment, and sea-level rise …

Habitat Associations And Detectability Of Three Unionid Species Along The Upper Sabine River In East Texas, Jared Dickson

Biology Theses

East Texas contains the highest diversity of mussels in the state. Of the 37 species in East Texas, six are listed by the state as threatened and three have been proposed for listing as threatened or endangered under the U.S. Endangered Species Act. Although diverse, mussel populations are declining and few studies exist that establish habitat relationships identifying determinants of mussel distributions in the upper Sabine River. I explored potential habitat preferences of three state listed species using an occupancy modeling approach, including the: Texas Pigtoe, Fusconaia askewi, Sandbank Pocketbook, Lampsilis satura, and Texas Heelsplitter, Potamilus amphicaenus. …

Geospatial Analysis Of Eastern Oyster Habitat And Disease In The Chesapeake Bay, Hannah Bradley

Senior Honors Projects, 2010-2019

Crassostrea virginica, common name eastern oyster, in the Chesapeake Bay is currently at 1% of its peak annual landings in 1884 (600,000 metric tons). This decline is in spite of being considered a resilient species. Causes of the decline include overharvesting, disease, and habitat loss. While efforts have been made to combat each cause, the key element to recovering the population is coordinated habitat restoration. This study aims to develop a GIS-based habitat model for the eastern oyster in the Chesapeake Bay. The first goal of this study was to determine the water quality parameters necessary for successful oyster …

Impervious Surface And Macroinvertebrates In The South Atlanta Metropolitan Area, Christopher H. Kodani

Georgia Journal of Science

Studies utilizing volunteer stream monitoring data are rare, particularly in in the Atlanta metropolitan area. This study investigated how the macroinvertebrate communities of 20 different stream sites in the south metropolitan Atlanta area were affected by the imperviousness of their surrounding watersheds. These sites were in a diverse landscape which included forests, wetlands, suburban day-use parks, and parking lots. Percentage impervious surface area was measured using Geographical Information System (GIS) analysis. Macroinvertebrates were collected using Georgia Adopt-A-Stream’s volunteer monitoring protocols, and a water quality index (WQI) was calculated from these data. The relationship between WQI and imperviousness was curvilinear and …

Sulfur Cave (Romania), An Extreme Environment With Microbial Mats In A Co2-H2S/O2 Gas Chemocline Dominated By Mycobacteria, Serban M. Sarbu, Joost W. Aerts, Jean-François Flot, Rob J.M. Van Spanning, Calin Baciu, Artur Ionescu, Boglárka M. Kis, Reka Incze, Sándor Sikó-Barabási, Zoltan Para, Botond Hegyeli, Nicu-Viorel Atudorei, Casey Barr, Kenneth Nealson, Ferenc L. Forray, Cristian Lascu, Emily J. Fleming, Wilbert Bitter, Radu Popa

International Journal of Speleology

Sulfur Cave (Puturosu Mountain, Romania) is an extreme environment, unique for displaying life in a gas chemocline. The lower part of the cave is filled with CO₂, CH₄, and H₂S of mofettic origin, while the upper part contains air that floats above the heavier volcanic gasses. S° and H₂SO₄ (from sulfur-oxidation) cover the cave wall at and below the CO₂-H₂S:O₂ gas/gas interface. On the cave wall, near the interface the pH is < 1 and unusual microbial biofilms occur on the rock’s surface. We provide context information on the geology, mineralogy, chemistry and biology to better understand this unique environment. We have used X-ray diffraction, optical microscopy, scanning electron microscopy with EDAX capabilities, stable isotope analysis and 16S and 18S rDNA amplicon sequencing. The most common taxa in the microbial biofilms are Mycobacteria, Acidithiobacillus and Ferroplasmaceae. Liquid water in this system originates solely from condensation of water …

Juvenile Amphibian Response To Oak And Maple Leaf Litter, Benjamin Breslau

Honors Scholar Theses

The composition of tree species within New England forests has changed significantly in recent decades, with an increase in maple (Acer spp.) abundance and a decrease in oak (Quercus spp.) abundance. Changing forest structure results in changing leaf litter composition of the forest floor, which influences the ground-dwelling amphibians that live in the litter. To better understand how changes to forest composition alters amphibian habitat quality, we recorded the growth and survival of 27 juvenile wood frogs (Lithobates sylvaticus or Rana sylvatica) and 27 juvenile American toads (Anaxyrus americanus) in response to leaf litter …

Cyanobacteria Reduce Quagga Mussel (Dreissena Rostriformis Bugensis) Spawning And Fertilization Success, Anna G. Boegehold, Nicholas S. Johnson, Jeffrey L. Ram, Donna R. Kashian

Environmental Science and Geology Faculty Research Publications

Quagga mussels (Dreissena rostriformis bugensis) are highly fecund broadcast spawners invasive to freshwaters of North America and western Europe. We hypothesized that environmental cues from phytoplankton can trigger gamete release in quagga mussels. Nutritious algae may stimulate dreissenid spawning, but less palatable food, such as bloom-forming cyanobacteria, could be a hindrance. The objective of our study was to test whether exposure to cyanobacteria can inhibit quagga mussel spawning and fertilization. We assessed spawning in the presence of serotonin, a known spawning inducer, where adult quagga mussels placed in individual vials were exposed to 13 cyanobacteria cultures and purified algal toxin …

Potential Benefits Of Restored Riparian Zones In An Agricultural Matrix For Bat Communities, Matthew T. Harris

Masters Theses, 2010-2019

Riparian buffers planted within agricultural matrices for wildlife conservation are expected to support numerous taxa, but a lack of empirical testing has limited evaluation of these practices. It is imperative that biologists and land managers understand how current conservation practices impact bats so that the ecosystem services provided by bats are maintained as farming practices continue to intensify in regions dominated by agriculture. This study evaluates the effects of planted riparian buffers along streams in an agricultural matrix by comparing acoustic bat activity along streams in active cattle pasture with activity at streams where riparian buffers have been planted. Forest …

Population Dynamics Of The Threatened Staghorn Coral, Acropora Cervicornis, And The Development Of A Species-Specific Monitoring Protocol, Elizabeth Goergen

HCNSO Student Theses and Dissertations

Historically, Acropora cervicornis was found in high densities on many Caribbean, Florida, and Gulf of Mexico reefs. A disease outbreak in the late 1970s and 80s caused up to 99% loss of A. cervicornis cover at some sites, leaving populations sparsely distributed throughout its range and typically found as isolated colonies. Even though populations are depauperate causing a decrease in sexual reproduction, its fast growth rate and ability to reproduce through asexual fragmentation affords this species the potential for quick recovery and population growth. However, limited to no natural recovery has been documented. Many of these populations are poorly studied …

Efficacy Of Magnesium Enriched Artificial Substrate For Oyster Restoration, Matthew Elder

Masters Theses, 2010-2019

The eastern oyster, Crassostrea virginica, is a keystone species that has undergone a large (> 95%) population decline due to overharvest, pollution, and disease. Restoration efforts focus on alternative larval attachment substrates such as concrete, to supplement the loss of natural oyster shell. Magnesium is a component of bivalve shells and its presence in the environment has shown to be important to the growth of mussels, but the same relationship has not been studied in oysters. Assuming that magnesium can be assimilated from the substrate on which the organism is growing, or that ions of magnesium are leached into …

Nutrient Limitation Of Algal Growth In Fishery Lakes, Madeline Ludwig

Biological and Agricultural Engineering Undergraduate Honors Theses

This study investigated the effect of nutrient addition on algal growth in three United States Forest Service lakes for fishery management in Arkansas. In fishery managed lakes, fertilization works by manipulating algae growth, a basal food resource in lakes, to promote the growth of the fish population. For the nutrient addition experiments, water was collected from each lake in cubitainers and spiked with nutrients; the treatments included the control, nitrogen (+N), phosphorus (+P), and nitrogen and phosphorus (+N +P). When algal growth was visually observed, a water sample was collected from each cubitainer and analyzed for chlorophyll-α. The results showed …

Gulls, Martin S. Lowney, Scott F. Beckerman, Scott C. Barras, Thomas W. Seamans

Wildlife Damage Management Technical Series

Abundant gull (Figure 1) populations in North America have led to a variety of conflicts with people. Gulls cause damage at aquaculture facilities and other properties, and often collide with aircraft. Their use of structures on and near water results in excessive amounts of bird droppings on boats and docks. Their presence near outdoor dining establishments, swimming beaches, and recreational sites can lead to negative interactions with people. Large amounts of gull fecal material pollutes water and beaches resulting in drinking water contamination and swim bans. A combination of dispersal techniques, exclusion and limited lethal control may reduce damage to …

Determining The Physiological And Behavioral Aspects Of Salinity Tolerance In The Asian Clam, Corbicula Fluminea, John Roden

Undergraduate Honors Theses

The Asian clam, Corbicula fluminea, is an invasive bivalve species that now occurs through most of the lower 48 United States. While a significant degree of salinity tolerance has been observed in C. fluminea, owing to its estuarine lineage, the physiological and behavioral responses to changes in salinity by these organisms are not completely understood. It was hypothesized that Corbicula would initially avoid elevated salinity levels (>1 g/L) behaviorally through valve closure, but would eventually have to open to dispel anaerobic waste products and deal with the salinity. To explore this, Corbicula were collected and put through …

Deciphering Climate-Driven Changes In Planktonic Diatom Communities In Lake Superior, Amy Kireta

Electronic Theses and Dissertations

Climate change is affecting lake systems throughout the world, including Lake Superior, the world’s largest lake by surface area. Climate-driven physical changes in Lake Superior are well documented, but there is still substantial uncertainty of how recent biological changes are related to climate change. This research addresses these uncertainties using a variety of approaches to understand the effects of modern climate-driven changes on Lake Superior diatom communities. First, I developed models for environmental variables related to diatom abundance using 10 years of summer monitoring data. Second, I investigated changes in fossilized diatom relative abundances before, during, and after the Medieval …

Big Data For Small Parks: Examining Regional Vegetation Patterns To Assess The Current Condition And Vulnerability Of Eastern National Parks To Climate Change, Kathryn M. Miller

Electronic Theses and Dissertations

The United States National Park Service mission is to preserve natural and cultural resources unimpaired for future generations. Given climate change, the paradigm of restoring natural resources to their pre-European settlement condition is no longer appropriate or achievable management. Instead, we must promote resilience and plan for adaptation. This approach poses many challenges, including knowledge gaps about the current condition of park ecosystems including wetlands, and lack of information about the matrix surrounding parks, which will strongly influence park ecosystem response to climate change. My dissertation research focused on filling these knowledge gaps to provide much needed information to managers …

Wildlife Use Of Vernal Pools In An Urbanizing Landscape With A Focus On Population Vitality Of Vernal Pool-Breeding Amphibians, Carly Jasmine Eakin Phd

Electronic Theses and Dissertations

Vernal pools in the northeastern United States provide essential habitat for pool-breeding amphibians and provide resources for other forest-dwelling wildlife. These pools and pool-breeding amphibians in particular are threatened by land conversion associated with urbanization and urban-associated factors. The responses of these amphibians and of birds and mammals using vernal pools to intermediate levels of urban development are largely unknown. I used field observations and lab experiments to study the amphibians, birds, and mammals associated with vernal pools along an urban development gradient in greater Bangor, Maine.

In Chapter 1, I examined bird and mammal use and assemblage composition at …

The Role And Contribution Of Saprotrophic Fungi During Standing Litter Decomposition Of Two Perennial Grass Species, Schizachyrium Scoparium And Schizachyrium Tenerum, Matthew Lodato

Master's Theses

In terrestrial ecosystems, most of the plant biomass produced enters the detrital pool, where microbial decomposers colonize, enzymatically degrade, and assimilate plant litter carbon and nutrients in amounts sufficient to bring about the decomposition of plant litter. Here, I estimated the biomass and production of fungi and microbial respiration associated with decaying Schizachyrium scoparium and Schizachyrium tenerum leaf litter, and constructed a partial organic matter budget estimating C flow into and through fungal decomposers. Significant losses in S. scoparium (57%) and S. tenerum (68%) leaf mass was observed during litter decomposition along with concomitant increases in fungal biomass, which reached …

Spatial Variation In Basal Resources And Trophic Position Of Selected Fishes Of The North-Central Gulf Of Mexico, Christopher Fleming

Master's Theses

The North-central Gulf of Mexico is a complex hydrologic environment with freshwater influx that varies on spatial and temporal scales. Freshwater input exerts influence on the isotope values of organisms living in coastal ecosystems. The objectives of this study were to determine relationships between total length and isotope value, estimate basal resource usage and trophic position of target species from Mississippi Sound, reef, and pelagic environments, and identify differences and similarities in spatial patterns of collection. Muscle tissue samples were collected from October 2014 through September 2015. Stable isotope analysis identified a trophic gradient extending from nearshore to offshore, with …

Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams

Electronic Theses and Dissertations

Oyster aquaculture is an expanding industry that relies on identifying and utilizing natural estuarine conditions for the economically viable production of a filter-feeding crop. The eastern oyster, Crassostrea virginica, is the principal species currently cultured in Maine. In addition to preferentially consumed phytoplankton, various detrital complexes (non-algal and/or non-living organic matter) may provide some nutrition to C. virginica between times of phytoplankton abundance. Here I investigated the importance of detrital proteins in supporting the growth of oysters cultured in the upper Damariscotta Estuary. Oyster aquaculture in this area is highly successful and previous reports indicate that labile detrital protein …

Linkages Between Marsh Fragmentation, Prey Availability, And Blue Crab (Callinectes Sapidus) Abundance And Mortality, Lennah Shakeri

Master's Theses

Coastal marshes are important nursery habitats for many commercially important invertebrate species, yet these marshes are being lost worldwide at an unprecedented rate due to subsidence, erosion, climate change, and human activity. As marsh is lost, it creates the opportunity for submerged aquatic vegetation (SAV) colonization and establishment in newly created open water areas. Blue crabs, Callinectes sapidus, use both marsh edge and SAV habitat during the juvenile stages and support one of the largest fisheries in the Gulf of Mexico, worth over $70 million in 2015. This thesis studied the linkages between habitat type, SAV cover, benthic prey …

Defending Wild Dogs: Population Dynamics And Disease In Endangered African Wild Dogs, Elizabeth Claire Arredondo

Graduate Theses and Dissertations

African wild dogs (Lycaon pictus) are endangered carnivores whose population is decreasing from habitat loss and fragmentation, interspecific competition, and disease. Survival rates are especially low in Kruger National Park (KNP), though it is unclear why. I estimated the abundance in KNP and survival rates over different time spans, six years and nine months, using public photographic survey data. In 2015, there were 298 (SE=12.1) individuals. Using a mark-recapture analysis in program R, I found that the survival rate between 2009-2015 was only 3.2%, and within the 9-month survey period (September 2014 – June 2015), monthly survival rates for the …

Ant Predation Of Blow Flies During Decomposition And Its Potential Impact On Pmi Estimations, Vincent J. Nappi

Student Theses

When an organism dies, the process of decomposition begins and many insects are attracted to the decomposing remains, or carrion, as a prospective food source for themselves, or their offspring. Blow flies (Family: Calliphoridae), in particular, are one of the first insects to discover and colonize a dead body due to the ability to detect a decomposing resource from large distances. As a result, forensic entomologists take advantage of the behavior and developmental cycles of early colonizers to calculate the post-mortem interval (PMI) in order to determine the time since death. However, along with the insects that are attracted to …

The Influence Of Conservation Tillage And Conventional Tillage On Soil Bacterial Diversity In Southern Illinois, Nasser Syed

Dissertations

Agriculture in the Midwest United States (Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin) is a critically important component of the United States economy and also for world exports of food grain. This is well reflected in the 2012 Census of Agriculture which showed that these states had a market value of crop and livestock products sold in excess of $80,000,000,000 (USDA, 2012). Within the U.S. the three Midwest states, Illinois, Iowa, and Minnesota are ranked 2nd, 3rd, and 4th for the economic value of crops sold. This economic value of agriculture in the Midwest encompasses not only corn, soybeans, …